~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

TOMOYO Linux Cross Reference
Linux/kernel/trace/ftrace.c

Version: ~ [ linux-4.18-rc1 ] ~ [ linux-4.17.2 ] ~ [ linux-4.16.16 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.50 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.109 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.138 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.19.8 ] ~ [ linux-3.18.113 ] ~ [ linux-3.17.8 ] ~ [ linux-3.16.57 ] ~ [ linux-3.15.10 ] ~ [ linux-3.14.79 ] ~ [ linux-3.13.11 ] ~ [ linux-3.12.74 ] ~ [ linux-3.11.10 ] ~ [ linux-3.10.108 ] ~ [ linux-3.9.11 ] ~ [ linux-3.8.13 ] ~ [ linux-3.7.10 ] ~ [ linux-3.6.11 ] ~ [ linux-3.5.7 ] ~ [ linux-3.4.113 ] ~ [ linux-3.3.8 ] ~ [ linux-3.2.102 ] ~ [ linux-3.1.10 ] ~ [ linux-3.0.101 ] ~ [ linux-2.6.39.4 ] ~ [ linux-2.6.38.8 ] ~ [ linux-2.6.37.6 ] ~ [ linux-2.6.36.4 ] ~ [ linux-2.6.35.14 ] ~ [ linux-2.6.34.15 ] ~ [ linux-2.6.33.20 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.27.62 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  1 /*
  2  * Infrastructure for profiling code inserted by 'gcc -pg'.
  3  *
  4  * Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com>
  5  * Copyright (C) 2004-2008 Ingo Molnar <mingo@redhat.com>
  6  *
  7  * Originally ported from the -rt patch by:
  8  *   Copyright (C) 2007 Arnaldo Carvalho de Melo <acme@redhat.com>
  9  *
 10  * Based on code in the latency_tracer, that is:
 11  *
 12  *  Copyright (C) 2004-2006 Ingo Molnar
 13  *  Copyright (C) 2004 Nadia Yvette Chambers
 14  */
 15 
 16 #include <linux/stop_machine.h>
 17 #include <linux/clocksource.h>
 18 #include <linux/sched/task.h>
 19 #include <linux/kallsyms.h>
 20 #include <linux/seq_file.h>
 21 #include <linux/suspend.h>
 22 #include <linux/tracefs.h>
 23 #include <linux/hardirq.h>
 24 #include <linux/kthread.h>
 25 #include <linux/uaccess.h>
 26 #include <linux/bsearch.h>
 27 #include <linux/module.h>
 28 #include <linux/ftrace.h>
 29 #include <linux/sysctl.h>
 30 #include <linux/slab.h>
 31 #include <linux/ctype.h>
 32 #include <linux/sort.h>
 33 #include <linux/list.h>
 34 #include <linux/hash.h>
 35 #include <linux/rcupdate.h>
 36 
 37 #include <trace/events/sched.h>
 38 
 39 #include <asm/sections.h>
 40 #include <asm/setup.h>
 41 
 42 #include "trace_output.h"
 43 #include "trace_stat.h"
 44 
 45 #define FTRACE_WARN_ON(cond)                    \
 46         ({                                      \
 47                 int ___r = cond;                \
 48                 if (WARN_ON(___r))              \
 49                         ftrace_kill();          \
 50                 ___r;                           \
 51         })
 52 
 53 #define FTRACE_WARN_ON_ONCE(cond)               \
 54         ({                                      \
 55                 int ___r = cond;                \
 56                 if (WARN_ON_ONCE(___r))         \
 57                         ftrace_kill();          \
 58                 ___r;                           \
 59         })
 60 
 61 /* hash bits for specific function selection */
 62 #define FTRACE_HASH_BITS 7
 63 #define FTRACE_FUNC_HASHSIZE (1 << FTRACE_HASH_BITS)
 64 #define FTRACE_HASH_DEFAULT_BITS 10
 65 #define FTRACE_HASH_MAX_BITS 12
 66 
 67 #ifdef CONFIG_DYNAMIC_FTRACE
 68 #define INIT_OPS_HASH(opsname)  \
 69         .func_hash              = &opsname.local_hash,                  \
 70         .local_hash.regex_lock  = __MUTEX_INITIALIZER(opsname.local_hash.regex_lock),
 71 #define ASSIGN_OPS_HASH(opsname, val) \
 72         .func_hash              = val, \
 73         .local_hash.regex_lock  = __MUTEX_INITIALIZER(opsname.local_hash.regex_lock),
 74 #else
 75 #define INIT_OPS_HASH(opsname)
 76 #define ASSIGN_OPS_HASH(opsname, val)
 77 #endif
 78 
 79 static struct ftrace_ops ftrace_list_end __read_mostly = {
 80         .func           = ftrace_stub,
 81         .flags          = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_STUB,
 82         INIT_OPS_HASH(ftrace_list_end)
 83 };
 84 
 85 /* ftrace_enabled is a method to turn ftrace on or off */
 86 int ftrace_enabled __read_mostly;
 87 static int last_ftrace_enabled;
 88 
 89 /* Current function tracing op */
 90 struct ftrace_ops *function_trace_op __read_mostly = &ftrace_list_end;
 91 /* What to set function_trace_op to */
 92 static struct ftrace_ops *set_function_trace_op;
 93 
 94 static bool ftrace_pids_enabled(struct ftrace_ops *ops)
 95 {
 96         struct trace_array *tr;
 97 
 98         if (!(ops->flags & FTRACE_OPS_FL_PID) || !ops->private)
 99                 return false;
100 
101         tr = ops->private;
102 
103         return tr->function_pids != NULL;
104 }
105 
106 static void ftrace_update_trampoline(struct ftrace_ops *ops);
107 
108 /*
109  * ftrace_disabled is set when an anomaly is discovered.
110  * ftrace_disabled is much stronger than ftrace_enabled.
111  */
112 static int ftrace_disabled __read_mostly;
113 
114 static DEFINE_MUTEX(ftrace_lock);
115 
116 static struct ftrace_ops __rcu *ftrace_ops_list __read_mostly = &ftrace_list_end;
117 ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub;
118 static struct ftrace_ops global_ops;
119 
120 #if ARCH_SUPPORTS_FTRACE_OPS
121 static void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
122                                  struct ftrace_ops *op, struct pt_regs *regs);
123 #else
124 /* See comment below, where ftrace_ops_list_func is defined */
125 static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip);
126 #define ftrace_ops_list_func ((ftrace_func_t)ftrace_ops_no_ops)
127 #endif
128 
129 /*
130  * Traverse the ftrace_global_list, invoking all entries.  The reason that we
131  * can use rcu_dereference_raw_notrace() is that elements removed from this list
132  * are simply leaked, so there is no need to interact with a grace-period
133  * mechanism.  The rcu_dereference_raw_notrace() calls are needed to handle
134  * concurrent insertions into the ftrace_global_list.
135  *
136  * Silly Alpha and silly pointer-speculation compiler optimizations!
137  */
138 #define do_for_each_ftrace_op(op, list)                 \
139         op = rcu_dereference_raw_notrace(list);                 \
140         do
141 
142 /*
143  * Optimized for just a single item in the list (as that is the normal case).
144  */
145 #define while_for_each_ftrace_op(op)                            \
146         while (likely(op = rcu_dereference_raw_notrace((op)->next)) &&  \
147                unlikely((op) != &ftrace_list_end))
148 
149 static inline void ftrace_ops_init(struct ftrace_ops *ops)
150 {
151 #ifdef CONFIG_DYNAMIC_FTRACE
152         if (!(ops->flags & FTRACE_OPS_FL_INITIALIZED)) {
153                 mutex_init(&ops->local_hash.regex_lock);
154                 ops->func_hash = &ops->local_hash;
155                 ops->flags |= FTRACE_OPS_FL_INITIALIZED;
156         }
157 #endif
158 }
159 
160 /**
161  * ftrace_nr_registered_ops - return number of ops registered
162  *
163  * Returns the number of ftrace_ops registered and tracing functions
164  */
165 int ftrace_nr_registered_ops(void)
166 {
167         struct ftrace_ops *ops;
168         int cnt = 0;
169 
170         mutex_lock(&ftrace_lock);
171 
172         for (ops = rcu_dereference_protected(ftrace_ops_list,
173                                              lockdep_is_held(&ftrace_lock));
174              ops != &ftrace_list_end;
175              ops = rcu_dereference_protected(ops->next,
176                                              lockdep_is_held(&ftrace_lock)))
177                 cnt++;
178 
179         mutex_unlock(&ftrace_lock);
180 
181         return cnt;
182 }
183 
184 static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip,
185                             struct ftrace_ops *op, struct pt_regs *regs)
186 {
187         struct trace_array *tr = op->private;
188 
189         if (tr && this_cpu_read(tr->trace_buffer.data->ftrace_ignore_pid))
190                 return;
191 
192         op->saved_func(ip, parent_ip, op, regs);
193 }
194 
195 /**
196  * clear_ftrace_function - reset the ftrace function
197  *
198  * This NULLs the ftrace function and in essence stops
199  * tracing.  There may be lag
200  */
201 void clear_ftrace_function(void)
202 {
203         ftrace_trace_function = ftrace_stub;
204 }
205 
206 static void ftrace_sync(struct work_struct *work)
207 {
208         /*
209          * This function is just a stub to implement a hard force
210          * of synchronize_sched(). This requires synchronizing
211          * tasks even in userspace and idle.
212          *
213          * Yes, function tracing is rude.
214          */
215 }
216 
217 static void ftrace_sync_ipi(void *data)
218 {
219         /* Probably not needed, but do it anyway */
220         smp_rmb();
221 }
222 
223 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
224 static void update_function_graph_func(void);
225 
226 /* Both enabled by default (can be cleared by function_graph tracer flags */
227 static bool fgraph_sleep_time = true;
228 static bool fgraph_graph_time = true;
229 
230 #else
231 static inline void update_function_graph_func(void) { }
232 #endif
233 
234 
235 static ftrace_func_t ftrace_ops_get_list_func(struct ftrace_ops *ops)
236 {
237         /*
238          * If this is a dynamic, RCU, or per CPU ops, or we force list func,
239          * then it needs to call the list anyway.
240          */
241         if (ops->flags & (FTRACE_OPS_FL_DYNAMIC | FTRACE_OPS_FL_RCU) ||
242             FTRACE_FORCE_LIST_FUNC)
243                 return ftrace_ops_list_func;
244 
245         return ftrace_ops_get_func(ops);
246 }
247 
248 static void update_ftrace_function(void)
249 {
250         ftrace_func_t func;
251 
252         /*
253          * Prepare the ftrace_ops that the arch callback will use.
254          * If there's only one ftrace_ops registered, the ftrace_ops_list
255          * will point to the ops we want.
256          */
257         set_function_trace_op = rcu_dereference_protected(ftrace_ops_list,
258                                                 lockdep_is_held(&ftrace_lock));
259 
260         /* If there's no ftrace_ops registered, just call the stub function */
261         if (set_function_trace_op == &ftrace_list_end) {
262                 func = ftrace_stub;
263 
264         /*
265          * If we are at the end of the list and this ops is
266          * recursion safe and not dynamic and the arch supports passing ops,
267          * then have the mcount trampoline call the function directly.
268          */
269         } else if (rcu_dereference_protected(ftrace_ops_list->next,
270                         lockdep_is_held(&ftrace_lock)) == &ftrace_list_end) {
271                 func = ftrace_ops_get_list_func(ftrace_ops_list);
272 
273         } else {
274                 /* Just use the default ftrace_ops */
275                 set_function_trace_op = &ftrace_list_end;
276                 func = ftrace_ops_list_func;
277         }
278 
279         update_function_graph_func();
280 
281         /* If there's no change, then do nothing more here */
282         if (ftrace_trace_function == func)
283                 return;
284 
285         /*
286          * If we are using the list function, it doesn't care
287          * about the function_trace_ops.
288          */
289         if (func == ftrace_ops_list_func) {
290                 ftrace_trace_function = func;
291                 /*
292                  * Don't even bother setting function_trace_ops,
293                  * it would be racy to do so anyway.
294                  */
295                 return;
296         }
297 
298 #ifndef CONFIG_DYNAMIC_FTRACE
299         /*
300          * For static tracing, we need to be a bit more careful.
301          * The function change takes affect immediately. Thus,
302          * we need to coorditate the setting of the function_trace_ops
303          * with the setting of the ftrace_trace_function.
304          *
305          * Set the function to the list ops, which will call the
306          * function we want, albeit indirectly, but it handles the
307          * ftrace_ops and doesn't depend on function_trace_op.
308          */
309         ftrace_trace_function = ftrace_ops_list_func;
310         /*
311          * Make sure all CPUs see this. Yes this is slow, but static
312          * tracing is slow and nasty to have enabled.
313          */
314         schedule_on_each_cpu(ftrace_sync);
315         /* Now all cpus are using the list ops. */
316         function_trace_op = set_function_trace_op;
317         /* Make sure the function_trace_op is visible on all CPUs */
318         smp_wmb();
319         /* Nasty way to force a rmb on all cpus */
320         smp_call_function(ftrace_sync_ipi, NULL, 1);
321         /* OK, we are all set to update the ftrace_trace_function now! */
322 #endif /* !CONFIG_DYNAMIC_FTRACE */
323 
324         ftrace_trace_function = func;
325 }
326 
327 int using_ftrace_ops_list_func(void)
328 {
329         return ftrace_trace_function == ftrace_ops_list_func;
330 }
331 
332 static void add_ftrace_ops(struct ftrace_ops __rcu **list,
333                            struct ftrace_ops *ops)
334 {
335         rcu_assign_pointer(ops->next, *list);
336 
337         /*
338          * We are entering ops into the list but another
339          * CPU might be walking that list. We need to make sure
340          * the ops->next pointer is valid before another CPU sees
341          * the ops pointer included into the list.
342          */
343         rcu_assign_pointer(*list, ops);
344 }
345 
346 static int remove_ftrace_ops(struct ftrace_ops __rcu **list,
347                              struct ftrace_ops *ops)
348 {
349         struct ftrace_ops **p;
350 
351         /*
352          * If we are removing the last function, then simply point
353          * to the ftrace_stub.
354          */
355         if (rcu_dereference_protected(*list,
356                         lockdep_is_held(&ftrace_lock)) == ops &&
357             rcu_dereference_protected(ops->next,
358                         lockdep_is_held(&ftrace_lock)) == &ftrace_list_end) {
359                 *list = &ftrace_list_end;
360                 return 0;
361         }
362 
363         for (p = list; *p != &ftrace_list_end; p = &(*p)->next)
364                 if (*p == ops)
365                         break;
366 
367         if (*p != ops)
368                 return -1;
369 
370         *p = (*p)->next;
371         return 0;
372 }
373 
374 static void ftrace_update_trampoline(struct ftrace_ops *ops);
375 
376 static int __register_ftrace_function(struct ftrace_ops *ops)
377 {
378         if (ops->flags & FTRACE_OPS_FL_DELETED)
379                 return -EINVAL;
380 
381         if (WARN_ON(ops->flags & FTRACE_OPS_FL_ENABLED))
382                 return -EBUSY;
383 
384 #ifndef CONFIG_DYNAMIC_FTRACE_WITH_REGS
385         /*
386          * If the ftrace_ops specifies SAVE_REGS, then it only can be used
387          * if the arch supports it, or SAVE_REGS_IF_SUPPORTED is also set.
388          * Setting SAVE_REGS_IF_SUPPORTED makes SAVE_REGS irrelevant.
389          */
390         if (ops->flags & FTRACE_OPS_FL_SAVE_REGS &&
391             !(ops->flags & FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED))
392                 return -EINVAL;
393 
394         if (ops->flags & FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED)
395                 ops->flags |= FTRACE_OPS_FL_SAVE_REGS;
396 #endif
397 
398         if (!core_kernel_data((unsigned long)ops))
399                 ops->flags |= FTRACE_OPS_FL_DYNAMIC;
400 
401         add_ftrace_ops(&ftrace_ops_list, ops);
402 
403         /* Always save the function, and reset at unregistering */
404         ops->saved_func = ops->func;
405 
406         if (ftrace_pids_enabled(ops))
407                 ops->func = ftrace_pid_func;
408 
409         ftrace_update_trampoline(ops);
410 
411         if (ftrace_enabled)
412                 update_ftrace_function();
413 
414         return 0;
415 }
416 
417 static int __unregister_ftrace_function(struct ftrace_ops *ops)
418 {
419         int ret;
420 
421         if (WARN_ON(!(ops->flags & FTRACE_OPS_FL_ENABLED)))
422                 return -EBUSY;
423 
424         ret = remove_ftrace_ops(&ftrace_ops_list, ops);
425 
426         if (ret < 0)
427                 return ret;
428 
429         if (ftrace_enabled)
430                 update_ftrace_function();
431 
432         ops->func = ops->saved_func;
433 
434         return 0;
435 }
436 
437 static void ftrace_update_pid_func(void)
438 {
439         struct ftrace_ops *op;
440 
441         /* Only do something if we are tracing something */
442         if (ftrace_trace_function == ftrace_stub)
443                 return;
444 
445         do_for_each_ftrace_op(op, ftrace_ops_list) {
446                 if (op->flags & FTRACE_OPS_FL_PID) {
447                         op->func = ftrace_pids_enabled(op) ?
448                                 ftrace_pid_func : op->saved_func;
449                         ftrace_update_trampoline(op);
450                 }
451         } while_for_each_ftrace_op(op);
452 
453         update_ftrace_function();
454 }
455 
456 #ifdef CONFIG_FUNCTION_PROFILER
457 struct ftrace_profile {
458         struct hlist_node               node;
459         unsigned long                   ip;
460         unsigned long                   counter;
461 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
462         unsigned long long              time;
463         unsigned long long              time_squared;
464 #endif
465 };
466 
467 struct ftrace_profile_page {
468         struct ftrace_profile_page      *next;
469         unsigned long                   index;
470         struct ftrace_profile           records[];
471 };
472 
473 struct ftrace_profile_stat {
474         atomic_t                        disabled;
475         struct hlist_head               *hash;
476         struct ftrace_profile_page      *pages;
477         struct ftrace_profile_page      *start;
478         struct tracer_stat              stat;
479 };
480 
481 #define PROFILE_RECORDS_SIZE                                            \
482         (PAGE_SIZE - offsetof(struct ftrace_profile_page, records))
483 
484 #define PROFILES_PER_PAGE                                       \
485         (PROFILE_RECORDS_SIZE / sizeof(struct ftrace_profile))
486 
487 static int ftrace_profile_enabled __read_mostly;
488 
489 /* ftrace_profile_lock - synchronize the enable and disable of the profiler */
490 static DEFINE_MUTEX(ftrace_profile_lock);
491 
492 static DEFINE_PER_CPU(struct ftrace_profile_stat, ftrace_profile_stats);
493 
494 #define FTRACE_PROFILE_HASH_BITS 10
495 #define FTRACE_PROFILE_HASH_SIZE (1 << FTRACE_PROFILE_HASH_BITS)
496 
497 static void *
498 function_stat_next(void *v, int idx)
499 {
500         struct ftrace_profile *rec = v;
501         struct ftrace_profile_page *pg;
502 
503         pg = (struct ftrace_profile_page *)((unsigned long)rec & PAGE_MASK);
504 
505  again:
506         if (idx != 0)
507                 rec++;
508 
509         if ((void *)rec >= (void *)&pg->records[pg->index]) {
510                 pg = pg->next;
511                 if (!pg)
512                         return NULL;
513                 rec = &pg->records[0];
514                 if (!rec->counter)
515                         goto again;
516         }
517 
518         return rec;
519 }
520 
521 static void *function_stat_start(struct tracer_stat *trace)
522 {
523         struct ftrace_profile_stat *stat =
524                 container_of(trace, struct ftrace_profile_stat, stat);
525 
526         if (!stat || !stat->start)
527                 return NULL;
528 
529         return function_stat_next(&stat->start->records[0], 0);
530 }
531 
532 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
533 /* function graph compares on total time */
534 static int function_stat_cmp(void *p1, void *p2)
535 {
536         struct ftrace_profile *a = p1;
537         struct ftrace_profile *b = p2;
538 
539         if (a->time < b->time)
540                 return -1;
541         if (a->time > b->time)
542                 return 1;
543         else
544                 return 0;
545 }
546 #else
547 /* not function graph compares against hits */
548 static int function_stat_cmp(void *p1, void *p2)
549 {
550         struct ftrace_profile *a = p1;
551         struct ftrace_profile *b = p2;
552 
553         if (a->counter < b->counter)
554                 return -1;
555         if (a->counter > b->counter)
556                 return 1;
557         else
558                 return 0;
559 }
560 #endif
561 
562 static int function_stat_headers(struct seq_file *m)
563 {
564 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
565         seq_puts(m, "  Function                               "
566                  "Hit    Time            Avg             s^2\n"
567                     "  --------                               "
568                  "---    ----            ---             ---\n");
569 #else
570         seq_puts(m, "  Function                               Hit\n"
571                     "  --------                               ---\n");
572 #endif
573         return 0;
574 }
575 
576 static int function_stat_show(struct seq_file *m, void *v)
577 {
578         struct ftrace_profile *rec = v;
579         char str[KSYM_SYMBOL_LEN];
580         int ret = 0;
581 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
582         static struct trace_seq s;
583         unsigned long long avg;
584         unsigned long long stddev;
585 #endif
586         mutex_lock(&ftrace_profile_lock);
587 
588         /* we raced with function_profile_reset() */
589         if (unlikely(rec->counter == 0)) {
590                 ret = -EBUSY;
591                 goto out;
592         }
593 
594 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
595         avg = rec->time;
596         do_div(avg, rec->counter);
597         if (tracing_thresh && (avg < tracing_thresh))
598                 goto out;
599 #endif
600 
601         kallsyms_lookup(rec->ip, NULL, NULL, NULL, str);
602         seq_printf(m, "  %-30.30s  %10lu", str, rec->counter);
603 
604 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
605         seq_puts(m, "    ");
606 
607         /* Sample standard deviation (s^2) */
608         if (rec->counter <= 1)
609                 stddev = 0;
610         else {
611                 /*
612                  * Apply Welford's method:
613                  * s^2 = 1 / (n * (n-1)) * (n * \Sum (x_i)^2 - (\Sum x_i)^2)
614                  */
615                 stddev = rec->counter * rec->time_squared -
616                          rec->time * rec->time;
617 
618                 /*
619                  * Divide only 1000 for ns^2 -> us^2 conversion.
620                  * trace_print_graph_duration will divide 1000 again.
621                  */
622                 do_div(stddev, rec->counter * (rec->counter - 1) * 1000);
623         }
624 
625         trace_seq_init(&s);
626         trace_print_graph_duration(rec->time, &s);
627         trace_seq_puts(&s, "    ");
628         trace_print_graph_duration(avg, &s);
629         trace_seq_puts(&s, "    ");
630         trace_print_graph_duration(stddev, &s);
631         trace_print_seq(m, &s);
632 #endif
633         seq_putc(m, '\n');
634 out:
635         mutex_unlock(&ftrace_profile_lock);
636 
637         return ret;
638 }
639 
640 static void ftrace_profile_reset(struct ftrace_profile_stat *stat)
641 {
642         struct ftrace_profile_page *pg;
643 
644         pg = stat->pages = stat->start;
645 
646         while (pg) {
647                 memset(pg->records, 0, PROFILE_RECORDS_SIZE);
648                 pg->index = 0;
649                 pg = pg->next;
650         }
651 
652         memset(stat->hash, 0,
653                FTRACE_PROFILE_HASH_SIZE * sizeof(struct hlist_head));
654 }
655 
656 int ftrace_profile_pages_init(struct ftrace_profile_stat *stat)
657 {
658         struct ftrace_profile_page *pg;
659         int functions;
660         int pages;
661         int i;
662 
663         /* If we already allocated, do nothing */
664         if (stat->pages)
665                 return 0;
666 
667         stat->pages = (void *)get_zeroed_page(GFP_KERNEL);
668         if (!stat->pages)
669                 return -ENOMEM;
670 
671 #ifdef CONFIG_DYNAMIC_FTRACE
672         functions = ftrace_update_tot_cnt;
673 #else
674         /*
675          * We do not know the number of functions that exist because
676          * dynamic tracing is what counts them. With past experience
677          * we have around 20K functions. That should be more than enough.
678          * It is highly unlikely we will execute every function in
679          * the kernel.
680          */
681         functions = 20000;
682 #endif
683 
684         pg = stat->start = stat->pages;
685 
686         pages = DIV_ROUND_UP(functions, PROFILES_PER_PAGE);
687 
688         for (i = 1; i < pages; i++) {
689                 pg->next = (void *)get_zeroed_page(GFP_KERNEL);
690                 if (!pg->next)
691                         goto out_free;
692                 pg = pg->next;
693         }
694 
695         return 0;
696 
697  out_free:
698         pg = stat->start;
699         while (pg) {
700                 unsigned long tmp = (unsigned long)pg;
701 
702                 pg = pg->next;
703                 free_page(tmp);
704         }
705 
706         stat->pages = NULL;
707         stat->start = NULL;
708 
709         return -ENOMEM;
710 }
711 
712 static int ftrace_profile_init_cpu(int cpu)
713 {
714         struct ftrace_profile_stat *stat;
715         int size;
716 
717         stat = &per_cpu(ftrace_profile_stats, cpu);
718 
719         if (stat->hash) {
720                 /* If the profile is already created, simply reset it */
721                 ftrace_profile_reset(stat);
722                 return 0;
723         }
724 
725         /*
726          * We are profiling all functions, but usually only a few thousand
727          * functions are hit. We'll make a hash of 1024 items.
728          */
729         size = FTRACE_PROFILE_HASH_SIZE;
730 
731         stat->hash = kcalloc(size, sizeof(struct hlist_head), GFP_KERNEL);
732 
733         if (!stat->hash)
734                 return -ENOMEM;
735 
736         /* Preallocate the function profiling pages */
737         if (ftrace_profile_pages_init(stat) < 0) {
738                 kfree(stat->hash);
739                 stat->hash = NULL;
740                 return -ENOMEM;
741         }
742 
743         return 0;
744 }
745 
746 static int ftrace_profile_init(void)
747 {
748         int cpu;
749         int ret = 0;
750 
751         for_each_possible_cpu(cpu) {
752                 ret = ftrace_profile_init_cpu(cpu);
753                 if (ret)
754                         break;
755         }
756 
757         return ret;
758 }
759 
760 /* interrupts must be disabled */
761 static struct ftrace_profile *
762 ftrace_find_profiled_func(struct ftrace_profile_stat *stat, unsigned long ip)
763 {
764         struct ftrace_profile *rec;
765         struct hlist_head *hhd;
766         unsigned long key;
767 
768         key = hash_long(ip, FTRACE_PROFILE_HASH_BITS);
769         hhd = &stat->hash[key];
770 
771         if (hlist_empty(hhd))
772                 return NULL;
773 
774         hlist_for_each_entry_rcu_notrace(rec, hhd, node) {
775                 if (rec->ip == ip)
776                         return rec;
777         }
778 
779         return NULL;
780 }
781 
782 static void ftrace_add_profile(struct ftrace_profile_stat *stat,
783                                struct ftrace_profile *rec)
784 {
785         unsigned long key;
786 
787         key = hash_long(rec->ip, FTRACE_PROFILE_HASH_BITS);
788         hlist_add_head_rcu(&rec->node, &stat->hash[key]);
789 }
790 
791 /*
792  * The memory is already allocated, this simply finds a new record to use.
793  */
794 static struct ftrace_profile *
795 ftrace_profile_alloc(struct ftrace_profile_stat *stat, unsigned long ip)
796 {
797         struct ftrace_profile *rec = NULL;
798 
799         /* prevent recursion (from NMIs) */
800         if (atomic_inc_return(&stat->disabled) != 1)
801                 goto out;
802 
803         /*
804          * Try to find the function again since an NMI
805          * could have added it
806          */
807         rec = ftrace_find_profiled_func(stat, ip);
808         if (rec)
809                 goto out;
810 
811         if (stat->pages->index == PROFILES_PER_PAGE) {
812                 if (!stat->pages->next)
813                         goto out;
814                 stat->pages = stat->pages->next;
815         }
816 
817         rec = &stat->pages->records[stat->pages->index++];
818         rec->ip = ip;
819         ftrace_add_profile(stat, rec);
820 
821  out:
822         atomic_dec(&stat->disabled);
823 
824         return rec;
825 }
826 
827 static void
828 function_profile_call(unsigned long ip, unsigned long parent_ip,
829                       struct ftrace_ops *ops, struct pt_regs *regs)
830 {
831         struct ftrace_profile_stat *stat;
832         struct ftrace_profile *rec;
833         unsigned long flags;
834 
835         if (!ftrace_profile_enabled)
836                 return;
837 
838         local_irq_save(flags);
839 
840         stat = this_cpu_ptr(&ftrace_profile_stats);
841         if (!stat->hash || !ftrace_profile_enabled)
842                 goto out;
843 
844         rec = ftrace_find_profiled_func(stat, ip);
845         if (!rec) {
846                 rec = ftrace_profile_alloc(stat, ip);
847                 if (!rec)
848                         goto out;
849         }
850 
851         rec->counter++;
852  out:
853         local_irq_restore(flags);
854 }
855 
856 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
857 static int profile_graph_entry(struct ftrace_graph_ent *trace)
858 {
859         int index = trace->depth;
860 
861         function_profile_call(trace->func, 0, NULL, NULL);
862 
863         /* If function graph is shutting down, ret_stack can be NULL */
864         if (!current->ret_stack)
865                 return 0;
866 
867         if (index >= 0 && index < FTRACE_RETFUNC_DEPTH)
868                 current->ret_stack[index].subtime = 0;
869 
870         return 1;
871 }
872 
873 static void profile_graph_return(struct ftrace_graph_ret *trace)
874 {
875         struct ftrace_profile_stat *stat;
876         unsigned long long calltime;
877         struct ftrace_profile *rec;
878         unsigned long flags;
879 
880         local_irq_save(flags);
881         stat = this_cpu_ptr(&ftrace_profile_stats);
882         if (!stat->hash || !ftrace_profile_enabled)
883                 goto out;
884 
885         /* If the calltime was zero'd ignore it */
886         if (!trace->calltime)
887                 goto out;
888 
889         calltime = trace->rettime - trace->calltime;
890 
891         if (!fgraph_graph_time) {
892                 int index;
893 
894                 index = trace->depth;
895 
896                 /* Append this call time to the parent time to subtract */
897                 if (index)
898                         current->ret_stack[index - 1].subtime += calltime;
899 
900                 if (current->ret_stack[index].subtime < calltime)
901                         calltime -= current->ret_stack[index].subtime;
902                 else
903                         calltime = 0;
904         }
905 
906         rec = ftrace_find_profiled_func(stat, trace->func);
907         if (rec) {
908                 rec->time += calltime;
909                 rec->time_squared += calltime * calltime;
910         }
911 
912  out:
913         local_irq_restore(flags);
914 }
915 
916 static int register_ftrace_profiler(void)
917 {
918         return register_ftrace_graph(&profile_graph_return,
919                                      &profile_graph_entry);
920 }
921 
922 static void unregister_ftrace_profiler(void)
923 {
924         unregister_ftrace_graph();
925 }
926 #else
927 static struct ftrace_ops ftrace_profile_ops __read_mostly = {
928         .func           = function_profile_call,
929         .flags          = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_INITIALIZED,
930         INIT_OPS_HASH(ftrace_profile_ops)
931 };
932 
933 static int register_ftrace_profiler(void)
934 {
935         return register_ftrace_function(&ftrace_profile_ops);
936 }
937 
938 static void unregister_ftrace_profiler(void)
939 {
940         unregister_ftrace_function(&ftrace_profile_ops);
941 }
942 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
943 
944 static ssize_t
945 ftrace_profile_write(struct file *filp, const char __user *ubuf,
946                      size_t cnt, loff_t *ppos)
947 {
948         unsigned long val;
949         int ret;
950 
951         ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
952         if (ret)
953                 return ret;
954 
955         val = !!val;
956 
957         mutex_lock(&ftrace_profile_lock);
958         if (ftrace_profile_enabled ^ val) {
959                 if (val) {
960                         ret = ftrace_profile_init();
961                         if (ret < 0) {
962                                 cnt = ret;
963                                 goto out;
964                         }
965 
966                         ret = register_ftrace_profiler();
967                         if (ret < 0) {
968                                 cnt = ret;
969                                 goto out;
970                         }
971                         ftrace_profile_enabled = 1;
972                 } else {
973                         ftrace_profile_enabled = 0;
974                         /*
975                          * unregister_ftrace_profiler calls stop_machine
976                          * so this acts like an synchronize_sched.
977                          */
978                         unregister_ftrace_profiler();
979                 }
980         }
981  out:
982         mutex_unlock(&ftrace_profile_lock);
983 
984         *ppos += cnt;
985 
986         return cnt;
987 }
988 
989 static ssize_t
990 ftrace_profile_read(struct file *filp, char __user *ubuf,
991                      size_t cnt, loff_t *ppos)
992 {
993         char buf[64];           /* big enough to hold a number */
994         int r;
995 
996         r = sprintf(buf, "%u\n", ftrace_profile_enabled);
997         return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
998 }
999 
1000 static const struct file_operations ftrace_profile_fops = {
1001         .open           = tracing_open_generic,
1002         .read           = ftrace_profile_read,
1003         .write          = ftrace_profile_write,
1004         .llseek         = default_llseek,
1005 };
1006 
1007 /* used to initialize the real stat files */
1008 static struct tracer_stat function_stats __initdata = {
1009         .name           = "functions",
1010         .stat_start     = function_stat_start,
1011         .stat_next      = function_stat_next,
1012         .stat_cmp       = function_stat_cmp,
1013         .stat_headers   = function_stat_headers,
1014         .stat_show      = function_stat_show
1015 };
1016 
1017 static __init void ftrace_profile_tracefs(struct dentry *d_tracer)
1018 {
1019         struct ftrace_profile_stat *stat;
1020         struct dentry *entry;
1021         char *name;
1022         int ret;
1023         int cpu;
1024 
1025         for_each_possible_cpu(cpu) {
1026                 stat = &per_cpu(ftrace_profile_stats, cpu);
1027 
1028                 name = kasprintf(GFP_KERNEL, "function%d", cpu);
1029                 if (!name) {
1030                         /*
1031                          * The files created are permanent, if something happens
1032                          * we still do not free memory.
1033                          */
1034                         WARN(1,
1035                              "Could not allocate stat file for cpu %d\n",
1036                              cpu);
1037                         return;
1038                 }
1039                 stat->stat = function_stats;
1040                 stat->stat.name = name;
1041                 ret = register_stat_tracer(&stat->stat);
1042                 if (ret) {
1043                         WARN(1,
1044                              "Could not register function stat for cpu %d\n",
1045                              cpu);
1046                         kfree(name);
1047                         return;
1048                 }
1049         }
1050 
1051         entry = tracefs_create_file("function_profile_enabled", 0644,
1052                                     d_tracer, NULL, &ftrace_profile_fops);
1053         if (!entry)
1054                 pr_warn("Could not create tracefs 'function_profile_enabled' entry\n");
1055 }
1056 
1057 #else /* CONFIG_FUNCTION_PROFILER */
1058 static __init void ftrace_profile_tracefs(struct dentry *d_tracer)
1059 {
1060 }
1061 #endif /* CONFIG_FUNCTION_PROFILER */
1062 
1063 static struct pid * const ftrace_swapper_pid = &init_struct_pid;
1064 
1065 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
1066 static int ftrace_graph_active;
1067 #else
1068 # define ftrace_graph_active 0
1069 #endif
1070 
1071 #ifdef CONFIG_DYNAMIC_FTRACE
1072 
1073 static struct ftrace_ops *removed_ops;
1074 
1075 /*
1076  * Set when doing a global update, like enabling all recs or disabling them.
1077  * It is not set when just updating a single ftrace_ops.
1078  */
1079 static bool update_all_ops;
1080 
1081 #ifndef CONFIG_FTRACE_MCOUNT_RECORD
1082 # error Dynamic ftrace depends on MCOUNT_RECORD
1083 #endif
1084 
1085 struct ftrace_func_entry {
1086         struct hlist_node hlist;
1087         unsigned long ip;
1088 };
1089 
1090 struct ftrace_func_probe {
1091         struct ftrace_probe_ops *probe_ops;
1092         struct ftrace_ops       ops;
1093         struct trace_array      *tr;
1094         struct list_head        list;
1095         void                    *data;
1096         int                     ref;
1097 };
1098 
1099 /*
1100  * We make these constant because no one should touch them,
1101  * but they are used as the default "empty hash", to avoid allocating
1102  * it all the time. These are in a read only section such that if
1103  * anyone does try to modify it, it will cause an exception.
1104  */
1105 static const struct hlist_head empty_buckets[1];
1106 static const struct ftrace_hash empty_hash = {
1107         .buckets = (struct hlist_head *)empty_buckets,
1108 };
1109 #define EMPTY_HASH      ((struct ftrace_hash *)&empty_hash)
1110 
1111 static struct ftrace_ops global_ops = {
1112         .func                           = ftrace_stub,
1113         .local_hash.notrace_hash        = EMPTY_HASH,
1114         .local_hash.filter_hash         = EMPTY_HASH,
1115         INIT_OPS_HASH(global_ops)
1116         .flags                          = FTRACE_OPS_FL_RECURSION_SAFE |
1117                                           FTRACE_OPS_FL_INITIALIZED |
1118                                           FTRACE_OPS_FL_PID,
1119 };
1120 
1121 /*
1122  * Used by the stack undwinder to know about dynamic ftrace trampolines.
1123  */
1124 struct ftrace_ops *ftrace_ops_trampoline(unsigned long addr)
1125 {
1126         struct ftrace_ops *op = NULL;
1127 
1128         /*
1129          * Some of the ops may be dynamically allocated,
1130          * they are freed after a synchronize_sched().
1131          */
1132         preempt_disable_notrace();
1133 
1134         do_for_each_ftrace_op(op, ftrace_ops_list) {
1135                 /*
1136                  * This is to check for dynamically allocated trampolines.
1137                  * Trampolines that are in kernel text will have
1138                  * core_kernel_text() return true.
1139                  */
1140                 if (op->trampoline && op->trampoline_size)
1141                         if (addr >= op->trampoline &&
1142                             addr < op->trampoline + op->trampoline_size) {
1143                                 preempt_enable_notrace();
1144                                 return op;
1145                         }
1146         } while_for_each_ftrace_op(op);
1147         preempt_enable_notrace();
1148 
1149         return NULL;
1150 }
1151 
1152 /*
1153  * This is used by __kernel_text_address() to return true if the
1154  * address is on a dynamically allocated trampoline that would
1155  * not return true for either core_kernel_text() or
1156  * is_module_text_address().
1157  */
1158 bool is_ftrace_trampoline(unsigned long addr)
1159 {
1160         return ftrace_ops_trampoline(addr) != NULL;
1161 }
1162 
1163 struct ftrace_page {
1164         struct ftrace_page      *next;
1165         struct dyn_ftrace       *records;
1166         int                     index;
1167         int                     size;
1168 };
1169 
1170 #define ENTRY_SIZE sizeof(struct dyn_ftrace)
1171 #define ENTRIES_PER_PAGE (PAGE_SIZE / ENTRY_SIZE)
1172 
1173 /* estimate from running different kernels */
1174 #define NR_TO_INIT              10000
1175 
1176 static struct ftrace_page       *ftrace_pages_start;
1177 static struct ftrace_page       *ftrace_pages;
1178 
1179 static __always_inline unsigned long
1180 ftrace_hash_key(struct ftrace_hash *hash, unsigned long ip)
1181 {
1182         if (hash->size_bits > 0)
1183                 return hash_long(ip, hash->size_bits);
1184 
1185         return 0;
1186 }
1187 
1188 /* Only use this function if ftrace_hash_empty() has already been tested */
1189 static __always_inline struct ftrace_func_entry *
1190 __ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip)
1191 {
1192         unsigned long key;
1193         struct ftrace_func_entry *entry;
1194         struct hlist_head *hhd;
1195 
1196         key = ftrace_hash_key(hash, ip);
1197         hhd = &hash->buckets[key];
1198 
1199         hlist_for_each_entry_rcu_notrace(entry, hhd, hlist) {
1200                 if (entry->ip == ip)
1201                         return entry;
1202         }
1203         return NULL;
1204 }
1205 
1206 /**
1207  * ftrace_lookup_ip - Test to see if an ip exists in an ftrace_hash
1208  * @hash: The hash to look at
1209  * @ip: The instruction pointer to test
1210  *
1211  * Search a given @hash to see if a given instruction pointer (@ip)
1212  * exists in it.
1213  *
1214  * Returns the entry that holds the @ip if found. NULL otherwise.
1215  */
1216 struct ftrace_func_entry *
1217 ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip)
1218 {
1219         if (ftrace_hash_empty(hash))
1220                 return NULL;
1221 
1222         return __ftrace_lookup_ip(hash, ip);
1223 }
1224 
1225 static void __add_hash_entry(struct ftrace_hash *hash,
1226                              struct ftrace_func_entry *entry)
1227 {
1228         struct hlist_head *hhd;
1229         unsigned long key;
1230 
1231         key = ftrace_hash_key(hash, entry->ip);
1232         hhd = &hash->buckets[key];
1233         hlist_add_head(&entry->hlist, hhd);
1234         hash->count++;
1235 }
1236 
1237 static int add_hash_entry(struct ftrace_hash *hash, unsigned long ip)
1238 {
1239         struct ftrace_func_entry *entry;
1240 
1241         entry = kmalloc(sizeof(*entry), GFP_KERNEL);
1242         if (!entry)
1243                 return -ENOMEM;
1244 
1245         entry->ip = ip;
1246         __add_hash_entry(hash, entry);
1247 
1248         return 0;
1249 }
1250 
1251 static void
1252 free_hash_entry(struct ftrace_hash *hash,
1253                   struct ftrace_func_entry *entry)
1254 {
1255         hlist_del(&entry->hlist);
1256         kfree(entry);
1257         hash->count--;
1258 }
1259 
1260 static void
1261 remove_hash_entry(struct ftrace_hash *hash,
1262                   struct ftrace_func_entry *entry)
1263 {
1264         hlist_del_rcu(&entry->hlist);
1265         hash->count--;
1266 }
1267 
1268 static void ftrace_hash_clear(struct ftrace_hash *hash)
1269 {
1270         struct hlist_head *hhd;
1271         struct hlist_node *tn;
1272         struct ftrace_func_entry *entry;
1273         int size = 1 << hash->size_bits;
1274         int i;
1275 
1276         if (!hash->count)
1277                 return;
1278 
1279         for (i = 0; i < size; i++) {
1280                 hhd = &hash->buckets[i];
1281                 hlist_for_each_entry_safe(entry, tn, hhd, hlist)
1282                         free_hash_entry(hash, entry);
1283         }
1284         FTRACE_WARN_ON(hash->count);
1285 }
1286 
1287 static void free_ftrace_mod(struct ftrace_mod_load *ftrace_mod)
1288 {
1289         list_del(&ftrace_mod->list);
1290         kfree(ftrace_mod->module);
1291         kfree(ftrace_mod->func);
1292         kfree(ftrace_mod);
1293 }
1294 
1295 static void clear_ftrace_mod_list(struct list_head *head)
1296 {
1297         struct ftrace_mod_load *p, *n;
1298 
1299         /* stack tracer isn't supported yet */
1300         if (!head)
1301                 return;
1302 
1303         mutex_lock(&ftrace_lock);
1304         list_for_each_entry_safe(p, n, head, list)
1305                 free_ftrace_mod(p);
1306         mutex_unlock(&ftrace_lock);
1307 }
1308 
1309 static void free_ftrace_hash(struct ftrace_hash *hash)
1310 {
1311         if (!hash || hash == EMPTY_HASH)
1312                 return;
1313         ftrace_hash_clear(hash);
1314         kfree(hash->buckets);
1315         kfree(hash);
1316 }
1317 
1318 static void __free_ftrace_hash_rcu(struct rcu_head *rcu)
1319 {
1320         struct ftrace_hash *hash;
1321 
1322         hash = container_of(rcu, struct ftrace_hash, rcu);
1323         free_ftrace_hash(hash);
1324 }
1325 
1326 static void free_ftrace_hash_rcu(struct ftrace_hash *hash)
1327 {
1328         if (!hash || hash == EMPTY_HASH)
1329                 return;
1330         call_rcu_sched(&hash->rcu, __free_ftrace_hash_rcu);
1331 }
1332 
1333 void ftrace_free_filter(struct ftrace_ops *ops)
1334 {
1335         ftrace_ops_init(ops);
1336         free_ftrace_hash(ops->func_hash->filter_hash);
1337         free_ftrace_hash(ops->func_hash->notrace_hash);
1338 }
1339 
1340 static struct ftrace_hash *alloc_ftrace_hash(int size_bits)
1341 {
1342         struct ftrace_hash *hash;
1343         int size;
1344 
1345         hash = kzalloc(sizeof(*hash), GFP_KERNEL);
1346         if (!hash)
1347                 return NULL;
1348 
1349         size = 1 << size_bits;
1350         hash->buckets = kcalloc(size, sizeof(*hash->buckets), GFP_KERNEL);
1351 
1352         if (!hash->buckets) {
1353                 kfree(hash);
1354                 return NULL;
1355         }
1356 
1357         hash->size_bits = size_bits;
1358 
1359         return hash;
1360 }
1361 
1362 
1363 static int ftrace_add_mod(struct trace_array *tr,
1364                           const char *func, const char *module,
1365                           int enable)
1366 {
1367         struct ftrace_mod_load *ftrace_mod;
1368         struct list_head *mod_head = enable ? &tr->mod_trace : &tr->mod_notrace;
1369 
1370         ftrace_mod = kzalloc(sizeof(*ftrace_mod), GFP_KERNEL);
1371         if (!ftrace_mod)
1372                 return -ENOMEM;
1373 
1374         ftrace_mod->func = kstrdup(func, GFP_KERNEL);
1375         ftrace_mod->module = kstrdup(module, GFP_KERNEL);
1376         ftrace_mod->enable = enable;
1377 
1378         if (!ftrace_mod->func || !ftrace_mod->module)
1379                 goto out_free;
1380 
1381         list_add(&ftrace_mod->list, mod_head);
1382 
1383         return 0;
1384 
1385  out_free:
1386         free_ftrace_mod(ftrace_mod);
1387 
1388         return -ENOMEM;
1389 }
1390 
1391 static struct ftrace_hash *
1392 alloc_and_copy_ftrace_hash(int size_bits, struct ftrace_hash *hash)
1393 {
1394         struct ftrace_func_entry *entry;
1395         struct ftrace_hash *new_hash;
1396         int size;
1397         int ret;
1398         int i;
1399 
1400         new_hash = alloc_ftrace_hash(size_bits);
1401         if (!new_hash)
1402                 return NULL;
1403 
1404         if (hash)
1405                 new_hash->flags = hash->flags;
1406 
1407         /* Empty hash? */
1408         if (ftrace_hash_empty(hash))
1409                 return new_hash;
1410 
1411         size = 1 << hash->size_bits;
1412         for (i = 0; i < size; i++) {
1413                 hlist_for_each_entry(entry, &hash->buckets[i], hlist) {
1414                         ret = add_hash_entry(new_hash, entry->ip);
1415                         if (ret < 0)
1416                                 goto free_hash;
1417                 }
1418         }
1419 
1420         FTRACE_WARN_ON(new_hash->count != hash->count);
1421 
1422         return new_hash;
1423 
1424  free_hash:
1425         free_ftrace_hash(new_hash);
1426         return NULL;
1427 }
1428 
1429 static void
1430 ftrace_hash_rec_disable_modify(struct ftrace_ops *ops, int filter_hash);
1431 static void
1432 ftrace_hash_rec_enable_modify(struct ftrace_ops *ops, int filter_hash);
1433 
1434 static int ftrace_hash_ipmodify_update(struct ftrace_ops *ops,
1435                                        struct ftrace_hash *new_hash);
1436 
1437 static struct ftrace_hash *
1438 __ftrace_hash_move(struct ftrace_hash *src)
1439 {
1440         struct ftrace_func_entry *entry;
1441         struct hlist_node *tn;
1442         struct hlist_head *hhd;
1443         struct ftrace_hash *new_hash;
1444         int size = src->count;
1445         int bits = 0;
1446         int i;
1447 
1448         /*
1449          * If the new source is empty, just return the empty_hash.
1450          */
1451         if (ftrace_hash_empty(src))
1452                 return EMPTY_HASH;
1453 
1454         /*
1455          * Make the hash size about 1/2 the # found
1456          */
1457         for (size /= 2; size; size >>= 1)
1458                 bits++;
1459 
1460         /* Don't allocate too much */
1461         if (bits > FTRACE_HASH_MAX_BITS)
1462                 bits = FTRACE_HASH_MAX_BITS;
1463 
1464         new_hash = alloc_ftrace_hash(bits);
1465         if (!new_hash)
1466                 return NULL;
1467 
1468         new_hash->flags = src->flags;
1469 
1470         size = 1 << src->size_bits;
1471         for (i = 0; i < size; i++) {
1472                 hhd = &src->buckets[i];
1473                 hlist_for_each_entry_safe(entry, tn, hhd, hlist) {
1474                         remove_hash_entry(src, entry);
1475                         __add_hash_entry(new_hash, entry);
1476                 }
1477         }
1478 
1479         return new_hash;
1480 }
1481 
1482 static int
1483 ftrace_hash_move(struct ftrace_ops *ops, int enable,
1484                  struct ftrace_hash **dst, struct ftrace_hash *src)
1485 {
1486         struct ftrace_hash *new_hash;
1487         int ret;
1488 
1489         /* Reject setting notrace hash on IPMODIFY ftrace_ops */
1490         if (ops->flags & FTRACE_OPS_FL_IPMODIFY && !enable)
1491                 return -EINVAL;
1492 
1493         new_hash = __ftrace_hash_move(src);
1494         if (!new_hash)
1495                 return -ENOMEM;
1496 
1497         /* Make sure this can be applied if it is IPMODIFY ftrace_ops */
1498         if (enable) {
1499                 /* IPMODIFY should be updated only when filter_hash updating */
1500                 ret = ftrace_hash_ipmodify_update(ops, new_hash);
1501                 if (ret < 0) {
1502                         free_ftrace_hash(new_hash);
1503                         return ret;
1504                 }
1505         }
1506 
1507         /*
1508          * Remove the current set, update the hash and add
1509          * them back.
1510          */
1511         ftrace_hash_rec_disable_modify(ops, enable);
1512 
1513         rcu_assign_pointer(*dst, new_hash);
1514 
1515         ftrace_hash_rec_enable_modify(ops, enable);
1516 
1517         return 0;
1518 }
1519 
1520 static bool hash_contains_ip(unsigned long ip,
1521                              struct ftrace_ops_hash *hash)
1522 {
1523         /*
1524          * The function record is a match if it exists in the filter
1525          * hash and not in the notrace hash. Note, an emty hash is
1526          * considered a match for the filter hash, but an empty
1527          * notrace hash is considered not in the notrace hash.
1528          */
1529         return (ftrace_hash_empty(hash->filter_hash) ||
1530                 __ftrace_lookup_ip(hash->filter_hash, ip)) &&
1531                 (ftrace_hash_empty(hash->notrace_hash) ||
1532                  !__ftrace_lookup_ip(hash->notrace_hash, ip));
1533 }
1534 
1535 /*
1536  * Test the hashes for this ops to see if we want to call
1537  * the ops->func or not.
1538  *
1539  * It's a match if the ip is in the ops->filter_hash or
1540  * the filter_hash does not exist or is empty,
1541  *  AND
1542  * the ip is not in the ops->notrace_hash.
1543  *
1544  * This needs to be called with preemption disabled as
1545  * the hashes are freed with call_rcu_sched().
1546  */
1547 static int
1548 ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip, void *regs)
1549 {
1550         struct ftrace_ops_hash hash;
1551         int ret;
1552 
1553 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
1554         /*
1555          * There's a small race when adding ops that the ftrace handler
1556          * that wants regs, may be called without them. We can not
1557          * allow that handler to be called if regs is NULL.
1558          */
1559         if (regs == NULL && (ops->flags & FTRACE_OPS_FL_SAVE_REGS))
1560                 return 0;
1561 #endif
1562 
1563         rcu_assign_pointer(hash.filter_hash, ops->func_hash->filter_hash);
1564         rcu_assign_pointer(hash.notrace_hash, ops->func_hash->notrace_hash);
1565 
1566         if (hash_contains_ip(ip, &hash))
1567                 ret = 1;
1568         else
1569                 ret = 0;
1570 
1571         return ret;
1572 }
1573 
1574 /*
1575  * This is a double for. Do not use 'break' to break out of the loop,
1576  * you must use a goto.
1577  */
1578 #define do_for_each_ftrace_rec(pg, rec)                                 \
1579         for (pg = ftrace_pages_start; pg; pg = pg->next) {              \
1580                 int _____i;                                             \
1581                 for (_____i = 0; _____i < pg->index; _____i++) {        \
1582                         rec = &pg->records[_____i];
1583 
1584 #define while_for_each_ftrace_rec()             \
1585                 }                               \
1586         }
1587 
1588 
1589 static int ftrace_cmp_recs(const void *a, const void *b)
1590 {
1591         const struct dyn_ftrace *key = a;
1592         const struct dyn_ftrace *rec = b;
1593 
1594         if (key->flags < rec->ip)
1595                 return -1;
1596         if (key->ip >= rec->ip + MCOUNT_INSN_SIZE)
1597                 return 1;
1598         return 0;
1599 }
1600 
1601 /**
1602  * ftrace_location_range - return the first address of a traced location
1603  *      if it touches the given ip range
1604  * @start: start of range to search.
1605  * @end: end of range to search (inclusive). @end points to the last byte
1606  *      to check.
1607  *
1608  * Returns rec->ip if the related ftrace location is a least partly within
1609  * the given address range. That is, the first address of the instruction
1610  * that is either a NOP or call to the function tracer. It checks the ftrace
1611  * internal tables to determine if the address belongs or not.
1612  */
1613 unsigned long ftrace_location_range(unsigned long start, unsigned long end)
1614 {
1615         struct ftrace_page *pg;
1616         struct dyn_ftrace *rec;
1617         struct dyn_ftrace key;
1618 
1619         key.ip = start;
1620         key.flags = end;        /* overload flags, as it is unsigned long */
1621 
1622         for (pg = ftrace_pages_start; pg; pg = pg->next) {
1623                 if (end < pg->records[0].ip ||
1624                     start >= (pg->records[pg->index - 1].ip + MCOUNT_INSN_SIZE))
1625                         continue;
1626                 rec = bsearch(&key, pg->records, pg->index,
1627                               sizeof(struct dyn_ftrace),
1628                               ftrace_cmp_recs);
1629                 if (rec)
1630                         return rec->ip;
1631         }
1632 
1633         return 0;
1634 }
1635 
1636 /**
1637  * ftrace_location - return true if the ip giving is a traced location
1638  * @ip: the instruction pointer to check
1639  *
1640  * Returns rec->ip if @ip given is a pointer to a ftrace location.
1641  * That is, the instruction that is either a NOP or call to
1642  * the function tracer. It checks the ftrace internal tables to
1643  * determine if the address belongs or not.
1644  */
1645 unsigned long ftrace_location(unsigned long ip)
1646 {
1647         return ftrace_location_range(ip, ip);
1648 }
1649 
1650 /**
1651  * ftrace_text_reserved - return true if range contains an ftrace location
1652  * @start: start of range to search
1653  * @end: end of range to search (inclusive). @end points to the last byte to check.
1654  *
1655  * Returns 1 if @start and @end contains a ftrace location.
1656  * That is, the instruction that is either a NOP or call to
1657  * the function tracer. It checks the ftrace internal tables to
1658  * determine if the address belongs or not.
1659  */
1660 int ftrace_text_reserved(const void *start, const void *end)
1661 {
1662         unsigned long ret;
1663 
1664         ret = ftrace_location_range((unsigned long)start,
1665                                     (unsigned long)end);
1666 
1667         return (int)!!ret;
1668 }
1669 
1670 /* Test if ops registered to this rec needs regs */
1671 static bool test_rec_ops_needs_regs(struct dyn_ftrace *rec)
1672 {
1673         struct ftrace_ops *ops;
1674         bool keep_regs = false;
1675 
1676         for (ops = ftrace_ops_list;
1677              ops != &ftrace_list_end; ops = ops->next) {
1678                 /* pass rec in as regs to have non-NULL val */
1679                 if (ftrace_ops_test(ops, rec->ip, rec)) {
1680                         if (ops->flags & FTRACE_OPS_FL_SAVE_REGS) {
1681                                 keep_regs = true;
1682                                 break;
1683                         }
1684                 }
1685         }
1686 
1687         return  keep_regs;
1688 }
1689 
1690 static bool __ftrace_hash_rec_update(struct ftrace_ops *ops,
1691                                      int filter_hash,
1692                                      bool inc)
1693 {
1694         struct ftrace_hash *hash;
1695         struct ftrace_hash *other_hash;
1696         struct ftrace_page *pg;
1697         struct dyn_ftrace *rec;
1698         bool update = false;
1699         int count = 0;
1700         int all = false;
1701 
1702         /* Only update if the ops has been registered */
1703         if (!(ops->flags & FTRACE_OPS_FL_ENABLED))
1704                 return false;
1705 
1706         /*
1707          * In the filter_hash case:
1708          *   If the count is zero, we update all records.
1709          *   Otherwise we just update the items in the hash.
1710          *
1711          * In the notrace_hash case:
1712          *   We enable the update in the hash.
1713          *   As disabling notrace means enabling the tracing,
1714          *   and enabling notrace means disabling, the inc variable
1715          *   gets inversed.
1716          */
1717         if (filter_hash) {
1718                 hash = ops->func_hash->filter_hash;
1719                 other_hash = ops->func_hash->notrace_hash;
1720                 if (ftrace_hash_empty(hash))
1721                         all = true;
1722         } else {
1723                 inc = !inc;
1724                 hash = ops->func_hash->notrace_hash;
1725                 other_hash = ops->func_hash->filter_hash;
1726                 /*
1727                  * If the notrace hash has no items,
1728                  * then there's nothing to do.
1729                  */
1730                 if (ftrace_hash_empty(hash))
1731                         return false;
1732         }
1733 
1734         do_for_each_ftrace_rec(pg, rec) {
1735                 int in_other_hash = 0;
1736                 int in_hash = 0;
1737                 int match = 0;
1738 
1739                 if (rec->flags & FTRACE_FL_DISABLED)
1740                         continue;
1741 
1742                 if (all) {
1743                         /*
1744                          * Only the filter_hash affects all records.
1745                          * Update if the record is not in the notrace hash.
1746                          */
1747                         if (!other_hash || !ftrace_lookup_ip(other_hash, rec->ip))
1748                                 match = 1;
1749                 } else {
1750                         in_hash = !!ftrace_lookup_ip(hash, rec->ip);
1751                         in_other_hash = !!ftrace_lookup_ip(other_hash, rec->ip);
1752 
1753                         /*
1754                          * If filter_hash is set, we want to match all functions
1755                          * that are in the hash but not in the other hash.
1756                          *
1757                          * If filter_hash is not set, then we are decrementing.
1758                          * That means we match anything that is in the hash
1759                          * and also in the other_hash. That is, we need to turn
1760                          * off functions in the other hash because they are disabled
1761                          * by this hash.
1762                          */
1763                         if (filter_hash && in_hash && !in_other_hash)
1764                                 match = 1;
1765                         else if (!filter_hash && in_hash &&
1766                                  (in_other_hash || ftrace_hash_empty(other_hash)))
1767                                 match = 1;
1768                 }
1769                 if (!match)
1770                         continue;
1771 
1772                 if (inc) {
1773                         rec->flags++;
1774                         if (FTRACE_WARN_ON(ftrace_rec_count(rec) == FTRACE_REF_MAX))
1775                                 return false;
1776 
1777                         /*
1778                          * If there's only a single callback registered to a
1779                          * function, and the ops has a trampoline registered
1780                          * for it, then we can call it directly.
1781                          */
1782                         if (ftrace_rec_count(rec) == 1 && ops->trampoline)
1783                                 rec->flags |= FTRACE_FL_TRAMP;
1784                         else
1785                                 /*
1786                                  * If we are adding another function callback
1787                                  * to this function, and the previous had a
1788                                  * custom trampoline in use, then we need to go
1789                                  * back to the default trampoline.
1790                                  */
1791                                 rec->flags &= ~FTRACE_FL_TRAMP;
1792 
1793                         /*
1794                          * If any ops wants regs saved for this function
1795                          * then all ops will get saved regs.
1796                          */
1797                         if (ops->flags & FTRACE_OPS_FL_SAVE_REGS)
1798                                 rec->flags |= FTRACE_FL_REGS;
1799                 } else {
1800                         if (FTRACE_WARN_ON(ftrace_rec_count(rec) == 0))
1801                                 return false;
1802                         rec->flags--;
1803 
1804                         /*
1805                          * If the rec had REGS enabled and the ops that is
1806                          * being removed had REGS set, then see if there is
1807                          * still any ops for this record that wants regs.
1808                          * If not, we can stop recording them.
1809                          */
1810                         if (ftrace_rec_count(rec) > 0 &&
1811                             rec->flags & FTRACE_FL_REGS &&
1812                             ops->flags & FTRACE_OPS_FL_SAVE_REGS) {
1813                                 if (!test_rec_ops_needs_regs(rec))
1814                                         rec->flags &= ~FTRACE_FL_REGS;
1815                         }
1816 
1817                         /*
1818                          * If the rec had TRAMP enabled, then it needs to
1819                          * be cleared. As TRAMP can only be enabled iff
1820                          * there is only a single ops attached to it.
1821                          * In otherwords, always disable it on decrementing.
1822                          * In the future, we may set it if rec count is
1823                          * decremented to one, and the ops that is left
1824                          * has a trampoline.
1825                          */
1826                         rec->flags &= ~FTRACE_FL_TRAMP;
1827 
1828                         /*
1829                          * flags will be cleared in ftrace_check_record()
1830                          * if rec count is zero.
1831                          */
1832                 }
1833                 count++;
1834 
1835                 /* Must match FTRACE_UPDATE_CALLS in ftrace_modify_all_code() */
1836                 update |= ftrace_test_record(rec, 1) != FTRACE_UPDATE_IGNORE;
1837 
1838                 /* Shortcut, if we handled all records, we are done. */
1839                 if (!all && count == hash->count)
1840                         return update;
1841         } while_for_each_ftrace_rec();
1842 
1843         return update;
1844 }
1845 
1846 static bool ftrace_hash_rec_disable(struct ftrace_ops *ops,
1847                                     int filter_hash)
1848 {
1849         return __ftrace_hash_rec_update(ops, filter_hash, 0);
1850 }
1851 
1852 static bool ftrace_hash_rec_enable(struct ftrace_ops *ops,
1853                                    int filter_hash)
1854 {
1855         return __ftrace_hash_rec_update(ops, filter_hash, 1);
1856 }
1857 
1858 static void ftrace_hash_rec_update_modify(struct ftrace_ops *ops,
1859                                           int filter_hash, int inc)
1860 {
1861         struct ftrace_ops *op;
1862 
1863         __ftrace_hash_rec_update(ops, filter_hash, inc);
1864 
1865         if (ops->func_hash != &global_ops.local_hash)
1866                 return;
1867 
1868         /*
1869          * If the ops shares the global_ops hash, then we need to update
1870          * all ops that are enabled and use this hash.
1871          */
1872         do_for_each_ftrace_op(op, ftrace_ops_list) {
1873                 /* Already done */
1874                 if (op == ops)
1875                         continue;
1876                 if (op->func_hash == &global_ops.local_hash)
1877                         __ftrace_hash_rec_update(op, filter_hash, inc);
1878         } while_for_each_ftrace_op(op);
1879 }
1880 
1881 static void ftrace_hash_rec_disable_modify(struct ftrace_ops *ops,
1882                                            int filter_hash)
1883 {
1884         ftrace_hash_rec_update_modify(ops, filter_hash, 0);
1885 }
1886 
1887 static void ftrace_hash_rec_enable_modify(struct ftrace_ops *ops,
1888                                           int filter_hash)
1889 {
1890         ftrace_hash_rec_update_modify(ops, filter_hash, 1);
1891 }
1892 
1893 /*
1894  * Try to update IPMODIFY flag on each ftrace_rec. Return 0 if it is OK
1895  * or no-needed to update, -EBUSY if it detects a conflict of the flag
1896  * on a ftrace_rec, and -EINVAL if the new_hash tries to trace all recs.
1897  * Note that old_hash and new_hash has below meanings
1898  *  - If the hash is NULL, it hits all recs (if IPMODIFY is set, this is rejected)
1899  *  - If the hash is EMPTY_HASH, it hits nothing
1900  *  - Anything else hits the recs which match the hash entries.
1901  */
1902 static int __ftrace_hash_update_ipmodify(struct ftrace_ops *ops,
1903                                          struct ftrace_hash *old_hash,
1904                                          struct ftrace_hash *new_hash)
1905 {
1906         struct ftrace_page *pg;
1907         struct dyn_ftrace *rec, *end = NULL;
1908         int in_old, in_new;
1909 
1910         /* Only update if the ops has been registered */
1911         if (!(ops->flags & FTRACE_OPS_FL_ENABLED))
1912                 return 0;
1913 
1914         if (!(ops->flags & FTRACE_OPS_FL_IPMODIFY))
1915                 return 0;
1916 
1917         /*
1918          * Since the IPMODIFY is a very address sensitive action, we do not
1919          * allow ftrace_ops to set all functions to new hash.
1920          */
1921         if (!new_hash || !old_hash)
1922                 return -EINVAL;
1923 
1924         /* Update rec->flags */
1925         do_for_each_ftrace_rec(pg, rec) {
1926 
1927                 if (rec->flags & FTRACE_FL_DISABLED)
1928                         continue;
1929 
1930                 /* We need to update only differences of filter_hash */
1931                 in_old = !!ftrace_lookup_ip(old_hash, rec->ip);
1932                 in_new = !!ftrace_lookup_ip(new_hash, rec->ip);
1933                 if (in_old == in_new)
1934                         continue;
1935 
1936                 if (in_new) {
1937                         /* New entries must ensure no others are using it */
1938                         if (rec->flags & FTRACE_FL_IPMODIFY)
1939                                 goto rollback;
1940                         rec->flags |= FTRACE_FL_IPMODIFY;
1941                 } else /* Removed entry */
1942                         rec->flags &= ~FTRACE_FL_IPMODIFY;
1943         } while_for_each_ftrace_rec();
1944 
1945         return 0;
1946 
1947 rollback:
1948         end = rec;
1949 
1950         /* Roll back what we did above */
1951         do_for_each_ftrace_rec(pg, rec) {
1952 
1953                 if (rec->flags & FTRACE_FL_DISABLED)
1954                         continue;
1955 
1956                 if (rec == end)
1957                         goto err_out;
1958 
1959                 in_old = !!ftrace_lookup_ip(old_hash, rec->ip);
1960                 in_new = !!ftrace_lookup_ip(new_hash, rec->ip);
1961                 if (in_old == in_new)
1962                         continue;
1963 
1964                 if (in_new)
1965                         rec->flags &= ~FTRACE_FL_IPMODIFY;
1966                 else
1967                         rec->flags |= FTRACE_FL_IPMODIFY;
1968         } while_for_each_ftrace_rec();
1969 
1970 err_out:
1971         return -EBUSY;
1972 }
1973 
1974 static int ftrace_hash_ipmodify_enable(struct ftrace_ops *ops)
1975 {
1976         struct ftrace_hash *hash = ops->func_hash->filter_hash;
1977 
1978         if (ftrace_hash_empty(hash))
1979                 hash = NULL;
1980 
1981         return __ftrace_hash_update_ipmodify(ops, EMPTY_HASH, hash);
1982 }
1983 
1984 /* Disabling always succeeds */
1985 static void ftrace_hash_ipmodify_disable(struct ftrace_ops *ops)
1986 {
1987         struct ftrace_hash *hash = ops->func_hash->filter_hash;
1988 
1989         if (ftrace_hash_empty(hash))
1990                 hash = NULL;
1991 
1992         __ftrace_hash_update_ipmodify(ops, hash, EMPTY_HASH);
1993 }
1994 
1995 static int ftrace_hash_ipmodify_update(struct ftrace_ops *ops,
1996                                        struct ftrace_hash *new_hash)
1997 {
1998         struct ftrace_hash *old_hash = ops->func_hash->filter_hash;
1999 
2000         if (ftrace_hash_empty(old_hash))
2001                 old_hash = NULL;
2002 
2003         if (ftrace_hash_empty(new_hash))
2004                 new_hash = NULL;
2005 
2006         return __ftrace_hash_update_ipmodify(ops, old_hash, new_hash);
2007 }
2008 
2009 static void print_ip_ins(const char *fmt, const unsigned char *p)
2010 {
2011         int i;
2012 
2013         printk(KERN_CONT "%s", fmt);
2014 
2015         for (i = 0; i < MCOUNT_INSN_SIZE; i++)
2016                 printk(KERN_CONT "%s%02x", i ? ":" : "", p[i]);
2017 }
2018 
2019 static struct ftrace_ops *
2020 ftrace_find_tramp_ops_any(struct dyn_ftrace *rec);
2021 static struct ftrace_ops *
2022 ftrace_find_tramp_ops_next(struct dyn_ftrace *rec, struct ftrace_ops *ops);
2023 
2024 enum ftrace_bug_type ftrace_bug_type;
2025 const void *ftrace_expected;
2026 
2027 static void print_bug_type(void)
2028 {
2029         switch (ftrace_bug_type) {
2030         case FTRACE_BUG_UNKNOWN:
2031                 break;
2032         case FTRACE_BUG_INIT:
2033                 pr_info("Initializing ftrace call sites\n");
2034                 break;
2035         case FTRACE_BUG_NOP:
2036                 pr_info("Setting ftrace call site to NOP\n");
2037                 break;
2038         case FTRACE_BUG_CALL:
2039                 pr_info("Setting ftrace call site to call ftrace function\n");
2040                 break;
2041         case FTRACE_BUG_UPDATE:
2042                 pr_info("Updating ftrace call site to call a different ftrace function\n");
2043                 break;
2044         }
2045 }
2046 
2047 /**
2048  * ftrace_bug - report and shutdown function tracer
2049  * @failed: The failed type (EFAULT, EINVAL, EPERM)
2050  * @rec: The record that failed
2051  *
2052  * The arch code that enables or disables the function tracing
2053  * can call ftrace_bug() when it has detected a problem in
2054  * modifying the code. @failed should be one of either:
2055  * EFAULT - if the problem happens on reading the @ip address
2056  * EINVAL - if what is read at @ip is not what was expected
2057  * EPERM - if the problem happens on writting to the @ip address
2058  */
2059 void ftrace_bug(int failed, struct dyn_ftrace *rec)
2060 {
2061         unsigned long ip = rec ? rec->ip : 0;
2062 
2063         switch (failed) {
2064         case -EFAULT:
2065                 FTRACE_WARN_ON_ONCE(1);
2066                 pr_info("ftrace faulted on modifying ");
2067                 print_ip_sym(ip);
2068                 break;
2069         case -EINVAL:
2070                 FTRACE_WARN_ON_ONCE(1);
2071                 pr_info("ftrace failed to modify ");
2072                 print_ip_sym(ip);
2073                 print_ip_ins(" actual:   ", (unsigned char *)ip);
2074                 pr_cont("\n");
2075                 if (ftrace_expected) {
2076                         print_ip_ins(" expected: ", ftrace_expected);
2077                         pr_cont("\n");
2078                 }
2079                 break;
2080         case -EPERM:
2081                 FTRACE_WARN_ON_ONCE(1);
2082                 pr_info("ftrace faulted on writing ");
2083                 print_ip_sym(ip);
2084                 break;
2085         default:
2086                 FTRACE_WARN_ON_ONCE(1);
2087                 pr_info("ftrace faulted on unknown error ");
2088                 print_ip_sym(ip);
2089         }
2090         print_bug_type();
2091         if (rec) {
2092                 struct ftrace_ops *ops = NULL;
2093 
2094                 pr_info("ftrace record flags: %lx\n", rec->flags);
2095                 pr_cont(" (%ld)%s", ftrace_rec_count(rec),
2096                         rec->flags & FTRACE_FL_REGS ? " R" : "  ");
2097                 if (rec->flags & FTRACE_FL_TRAMP_EN) {
2098                         ops = ftrace_find_tramp_ops_any(rec);
2099                         if (ops) {
2100                                 do {
2101                                         pr_cont("\ttramp: %pS (%pS)",
2102                                                 (void *)ops->trampoline,
2103                                                 (void *)ops->func);
2104                                         ops = ftrace_find_tramp_ops_next(rec, ops);
2105                                 } while (ops);
2106                         } else
2107                                 pr_cont("\ttramp: ERROR!");
2108 
2109                 }
2110                 ip = ftrace_get_addr_curr(rec);
2111                 pr_cont("\n expected tramp: %lx\n", ip);
2112         }
2113 }
2114 
2115 static int ftrace_check_record(struct dyn_ftrace *rec, int enable, int update)
2116 {
2117         unsigned long flag = 0UL;
2118 
2119         ftrace_bug_type = FTRACE_BUG_UNKNOWN;
2120 
2121         if (rec->flags & FTRACE_FL_DISABLED)
2122                 return FTRACE_UPDATE_IGNORE;
2123 
2124         /*
2125          * If we are updating calls:
2126          *
2127          *   If the record has a ref count, then we need to enable it
2128          *   because someone is using it.
2129          *
2130          *   Otherwise we make sure its disabled.
2131          *
2132          * If we are disabling calls, then disable all records that
2133          * are enabled.
2134          */
2135         if (enable && ftrace_rec_count(rec))
2136                 flag = FTRACE_FL_ENABLED;
2137 
2138         /*
2139          * If enabling and the REGS flag does not match the REGS_EN, or
2140          * the TRAMP flag doesn't match the TRAMP_EN, then do not ignore
2141          * this record. Set flags to fail the compare against ENABLED.
2142          */
2143         if (flag) {
2144                 if (!(rec->flags & FTRACE_FL_REGS) != 
2145                     !(rec->flags & FTRACE_FL_REGS_EN))
2146                         flag |= FTRACE_FL_REGS;
2147 
2148                 if (!(rec->flags & FTRACE_FL_TRAMP) != 
2149                     !(rec->flags & FTRACE_FL_TRAMP_EN))
2150                         flag |= FTRACE_FL_TRAMP;
2151         }
2152 
2153         /* If the state of this record hasn't changed, then do nothing */
2154         if ((rec->flags & FTRACE_FL_ENABLED) == flag)
2155                 return FTRACE_UPDATE_IGNORE;
2156 
2157         if (flag) {
2158                 /* Save off if rec is being enabled (for return value) */
2159                 flag ^= rec->flags & FTRACE_FL_ENABLED;
2160 
2161                 if (update) {
2162                         rec->flags |= FTRACE_FL_ENABLED;
2163                         if (flag & FTRACE_FL_REGS) {
2164                                 if (rec->flags & FTRACE_FL_REGS)
2165                                         rec->flags |= FTRACE_FL_REGS_EN;
2166                                 else
2167                                         rec->flags &= ~FTRACE_FL_REGS_EN;
2168                         }
2169                         if (flag & FTRACE_FL_TRAMP) {
2170                                 if (rec->flags & FTRACE_FL_TRAMP)
2171                                         rec->flags |= FTRACE_FL_TRAMP_EN;
2172                                 else
2173                                         rec->flags &= ~FTRACE_FL_TRAMP_EN;
2174                         }
2175                 }
2176 
2177                 /*
2178                  * If this record is being updated from a nop, then
2179                  *   return UPDATE_MAKE_CALL.
2180                  * Otherwise,
2181                  *   return UPDATE_MODIFY_CALL to tell the caller to convert
2182                  *   from the save regs, to a non-save regs function or
2183                  *   vice versa, or from a trampoline call.
2184                  */
2185                 if (flag & FTRACE_FL_ENABLED) {
2186                         ftrace_bug_type = FTRACE_BUG_CALL;
2187                         return FTRACE_UPDATE_MAKE_CALL;
2188                 }
2189 
2190                 ftrace_bug_type = FTRACE_BUG_UPDATE;
2191                 return FTRACE_UPDATE_MODIFY_CALL;
2192         }
2193 
2194         if (update) {
2195                 /* If there's no more users, clear all flags */
2196                 if (!ftrace_rec_count(rec))
2197                         rec->flags = 0;
2198                 else
2199                         /*
2200                          * Just disable the record, but keep the ops TRAMP
2201                          * and REGS states. The _EN flags must be disabled though.
2202                          */
2203                         rec->flags &= ~(FTRACE_FL_ENABLED | FTRACE_FL_TRAMP_EN |
2204                                         FTRACE_FL_REGS_EN);
2205         }
2206 
2207         ftrace_bug_type = FTRACE_BUG_NOP;
2208         return FTRACE_UPDATE_MAKE_NOP;
2209 }
2210 
2211 /**
2212  * ftrace_update_record, set a record that now is tracing or not
2213  * @rec: the record to update
2214  * @enable: set to 1 if the record is tracing, zero to force disable
2215  *
2216  * The records that represent all functions that can be traced need
2217  * to be updated when tracing has been enabled.
2218  */
2219 int ftrace_update_record(struct dyn_ftrace *rec, int enable)
2220 {
2221         return ftrace_check_record(rec, enable, 1);
2222 }
2223 
2224 /**
2225  * ftrace_test_record, check if the record has been enabled or not
2226  * @rec: the record to test
2227  * @enable: set to 1 to check if enabled, 0 if it is disabled
2228  *
2229  * The arch code may need to test if a record is already set to
2230  * tracing to determine how to modify the function code that it
2231  * represents.
2232  */
2233 int ftrace_test_record(struct dyn_ftrace *rec, int enable)
2234 {
2235         return ftrace_check_record(rec, enable, 0);
2236 }
2237 
2238 static struct ftrace_ops *
2239 ftrace_find_tramp_ops_any(struct dyn_ftrace *rec)
2240 {
2241         struct ftrace_ops *op;
2242         unsigned long ip = rec->ip;
2243 
2244         do_for_each_ftrace_op(op, ftrace_ops_list) {
2245 
2246                 if (!op->trampoline)
2247                         continue;
2248 
2249                 if (hash_contains_ip(ip, op->func_hash))
2250                         return op;
2251         } while_for_each_ftrace_op(op);
2252 
2253         return NULL;
2254 }
2255 
2256 static struct ftrace_ops *
2257 ftrace_find_tramp_ops_next(struct dyn_ftrace *rec,
2258                            struct ftrace_ops *op)
2259 {
2260         unsigned long ip = rec->ip;
2261 
2262         while_for_each_ftrace_op(op) {
2263 
2264                 if (!op->trampoline)
2265                         continue;
2266 
2267                 if (hash_contains_ip(ip, op->func_hash))
2268                         return op;
2269         } 
2270 
2271         return NULL;
2272 }
2273 
2274 static struct ftrace_ops *
2275 ftrace_find_tramp_ops_curr(struct dyn_ftrace *rec)
2276 {
2277         struct ftrace_ops *op;
2278         unsigned long ip = rec->ip;
2279 
2280         /*
2281          * Need to check removed ops first.
2282          * If they are being removed, and this rec has a tramp,
2283          * and this rec is in the ops list, then it would be the
2284          * one with the tramp.
2285          */
2286         if (removed_ops) {
2287                 if (hash_contains_ip(ip, &removed_ops->old_hash))
2288                         return removed_ops;
2289         }
2290 
2291         /*
2292          * Need to find the current trampoline for a rec.
2293          * Now, a trampoline is only attached to a rec if there
2294          * was a single 'ops' attached to it. But this can be called
2295          * when we are adding another op to the rec or removing the
2296          * current one. Thus, if the op is being added, we can
2297          * ignore it because it hasn't attached itself to the rec
2298          * yet.
2299          *
2300          * If an ops is being modified (hooking to different functions)
2301          * then we don't care about the new functions that are being
2302          * added, just the old ones (that are probably being removed).
2303          *
2304          * If we are adding an ops to a function that already is using
2305          * a trampoline, it needs to be removed (trampolines are only
2306          * for single ops connected), then an ops that is not being
2307          * modified also needs to be checked.
2308          */
2309         do_for_each_ftrace_op(op, ftrace_ops_list) {
2310 
2311                 if (!op->trampoline)
2312                         continue;
2313 
2314                 /*
2315                  * If the ops is being added, it hasn't gotten to
2316                  * the point to be removed from this tree yet.
2317                  */
2318                 if (op->flags & FTRACE_OPS_FL_ADDING)
2319                         continue;
2320 
2321 
2322                 /*
2323                  * If the ops is being modified and is in the old
2324                  * hash, then it is probably being removed from this
2325                  * function.
2326                  */
2327                 if ((op->flags & FTRACE_OPS_FL_MODIFYING) &&
2328                     hash_contains_ip(ip, &op->old_hash))
2329                         return op;
2330                 /*
2331                  * If the ops is not being added or modified, and it's
2332                  * in its normal filter hash, then this must be the one
2333                  * we want!
2334                  */
2335                 if (!(op->flags & FTRACE_OPS_FL_MODIFYING) &&
2336                     hash_contains_ip(ip, op->func_hash))
2337                         return op;
2338 
2339         } while_for_each_ftrace_op(op);
2340 
2341         return NULL;
2342 }
2343 
2344 static struct ftrace_ops *
2345 ftrace_find_tramp_ops_new(struct dyn_ftrace *rec)
2346 {
2347         struct ftrace_ops *op;
2348         unsigned long ip = rec->ip;
2349 
2350         do_for_each_ftrace_op(op, ftrace_ops_list) {
2351                 /* pass rec in as regs to have non-NULL val */
2352                 if (hash_contains_ip(ip, op->func_hash))
2353                         return op;
2354         } while_for_each_ftrace_op(op);
2355 
2356         return NULL;
2357 }
2358 
2359 /**
2360  * ftrace_get_addr_new - Get the call address to set to
2361  * @rec:  The ftrace record descriptor
2362  *
2363  * If the record has the FTRACE_FL_REGS set, that means that it
2364  * wants to convert to a callback that saves all regs. If FTRACE_FL_REGS
2365  * is not not set, then it wants to convert to the normal callback.
2366  *
2367  * Returns the address of the trampoline to set to
2368  */
2369 unsigned long ftrace_get_addr_new(struct dyn_ftrace *rec)
2370 {
2371         struct ftrace_ops *ops;
2372 
2373         /* Trampolines take precedence over regs */
2374         if (rec->flags & FTRACE_FL_TRAMP) {
2375                 ops = ftrace_find_tramp_ops_new(rec);
2376                 if (FTRACE_WARN_ON(!ops || !ops->trampoline)) {
2377                         pr_warn("Bad trampoline accounting at: %p (%pS) (%lx)\n",
2378                                 (void *)rec->ip, (void *)rec->ip, rec->flags);
2379                         /* Ftrace is shutting down, return anything */
2380                         return (unsigned long)FTRACE_ADDR;
2381                 }
2382                 return ops->trampoline;
2383         }
2384 
2385         if (rec->flags & FTRACE_FL_REGS)
2386                 return (unsigned long)FTRACE_REGS_ADDR;
2387         else
2388                 return (unsigned long)FTRACE_ADDR;
2389 }
2390 
2391 /**
2392  * ftrace_get_addr_curr - Get the call address that is already there
2393  * @rec:  The ftrace record descriptor
2394  *
2395  * The FTRACE_FL_REGS_EN is set when the record already points to
2396  * a function that saves all the regs. Basically the '_EN' version
2397  * represents the current state of the function.
2398  *
2399  * Returns the address of the trampoline that is currently being called
2400  */
2401 unsigned long ftrace_get_addr_curr(struct dyn_ftrace *rec)
2402 {
2403         struct ftrace_ops *ops;
2404 
2405         /* Trampolines take precedence over regs */
2406         if (rec->flags & FTRACE_FL_TRAMP_EN) {
2407                 ops = ftrace_find_tramp_ops_curr(rec);
2408                 if (FTRACE_WARN_ON(!ops)) {
2409                         pr_warn("Bad trampoline accounting at: %p (%pS)\n",
2410                                 (void *)rec->ip, (void *)rec->ip);
2411                         /* Ftrace is shutting down, return anything */
2412                         return (unsigned long)FTRACE_ADDR;
2413                 }
2414                 return ops->trampoline;
2415         }
2416 
2417         if (rec->flags & FTRACE_FL_REGS_EN)
2418                 return (unsigned long)FTRACE_REGS_ADDR;
2419         else
2420                 return (unsigned long)FTRACE_ADDR;
2421 }
2422 
2423 static int
2424 __ftrace_replace_code(struct dyn_ftrace *rec, int enable)
2425 {
2426         unsigned long ftrace_old_addr;
2427         unsigned long ftrace_addr;
2428         int ret;
2429 
2430         ftrace_addr = ftrace_get_addr_new(rec);
2431 
2432         /* This needs to be done before we call ftrace_update_record */
2433         ftrace_old_addr = ftrace_get_addr_curr(rec);
2434 
2435         ret = ftrace_update_record(rec, enable);
2436 
2437         ftrace_bug_type = FTRACE_BUG_UNKNOWN;
2438 
2439         switch (ret) {
2440         case FTRACE_UPDATE_IGNORE:
2441                 return 0;
2442 
2443         case FTRACE_UPDATE_MAKE_CALL:
2444                 ftrace_bug_type = FTRACE_BUG_CALL;
2445                 return ftrace_make_call(rec, ftrace_addr);
2446 
2447         case FTRACE_UPDATE_MAKE_NOP:
2448                 ftrace_bug_type = FTRACE_BUG_NOP;
2449                 return ftrace_make_nop(NULL, rec, ftrace_old_addr);
2450 
2451         case FTRACE_UPDATE_MODIFY_CALL:
2452                 ftrace_bug_type = FTRACE_BUG_UPDATE;
2453                 return ftrace_modify_call(rec, ftrace_old_addr, ftrace_addr);
2454         }
2455 
2456         return -1; /* unknow ftrace bug */
2457 }
2458 
2459 void __weak ftrace_replace_code(int enable)
2460 {
2461         struct dyn_ftrace *rec;
2462         struct ftrace_page *pg;
2463         int failed;
2464 
2465         if (unlikely(ftrace_disabled))
2466                 return;
2467 
2468         do_for_each_ftrace_rec(pg, rec) {
2469 
2470                 if (rec->flags & FTRACE_FL_DISABLED)
2471                         continue;
2472 
2473                 failed = __ftrace_replace_code(rec, enable);
2474                 if (failed) {
2475                         ftrace_bug(failed, rec);
2476                         /* Stop processing */
2477                         return;
2478                 }
2479         } while_for_each_ftrace_rec();
2480 }
2481 
2482 struct ftrace_rec_iter {
2483         struct ftrace_page      *pg;
2484         int                     index;
2485 };
2486 
2487 /**
2488  * ftrace_rec_iter_start, start up iterating over traced functions
2489  *
2490  * Returns an iterator handle that is used to iterate over all
2491  * the records that represent address locations where functions
2492  * are traced.
2493  *
2494  * May return NULL if no records are available.
2495  */
2496 struct ftrace_rec_iter *ftrace_rec_iter_start(void)
2497 {
2498         /*
2499          * We only use a single iterator.
2500          * Protected by the ftrace_lock mutex.
2501          */
2502         static struct ftrace_rec_iter ftrace_rec_iter;
2503         struct ftrace_rec_iter *iter = &ftrace_rec_iter;
2504 
2505         iter->pg = ftrace_pages_start;
2506         iter->index = 0;
2507 
2508         /* Could have empty pages */
2509         while (iter->pg && !iter->pg->index)
2510                 iter->pg = iter->pg->next;
2511 
2512         if (!iter->pg)
2513                 return NULL;
2514 
2515         return iter;
2516 }
2517 
2518 /**
2519  * ftrace_rec_iter_next, get the next record to process.
2520  * @iter: The handle to the iterator.
2521  *
2522  * Returns the next iterator after the given iterator @iter.
2523  */
2524 struct ftrace_rec_iter *ftrace_rec_iter_next(struct ftrace_rec_iter *iter)
2525 {
2526         iter->index++;
2527 
2528         if (iter->index >= iter->pg->index) {
2529                 iter->pg = iter->pg->next;
2530                 iter->index = 0;
2531 
2532                 /* Could have empty pages */
2533                 while (iter->pg && !iter->pg->index)
2534                         iter->pg = iter->pg->next;
2535         }
2536 
2537         if (!iter->pg)
2538                 return NULL;
2539 
2540         return iter;
2541 }
2542 
2543 /**
2544  * ftrace_rec_iter_record, get the record at the iterator location
2545  * @iter: The current iterator location
2546  *
2547  * Returns the record that the current @iter is at.
2548  */
2549 struct dyn_ftrace *ftrace_rec_iter_record(struct ftrace_rec_iter *iter)
2550 {
2551         return &iter->pg->records[iter->index];
2552 }
2553 
2554 static int
2555 ftrace_code_disable(struct module *mod, struct dyn_ftrace *rec)
2556 {
2557         int ret;
2558 
2559         if (unlikely(ftrace_disabled))
2560                 return 0;
2561 
2562         ret = ftrace_make_nop(mod, rec, MCOUNT_ADDR);
2563         if (ret) {
2564                 ftrace_bug_type = FTRACE_BUG_INIT;
2565                 ftrace_bug(ret, rec);
2566                 return 0;
2567         }
2568         return 1;
2569 }
2570 
2571 /*
2572  * archs can override this function if they must do something
2573  * before the modifying code is performed.
2574  */
2575 int __weak ftrace_arch_code_modify_prepare(void)
2576 {
2577         return 0;
2578 }
2579 
2580 /*
2581  * archs can override this function if they must do something
2582  * after the modifying code is performed.
2583  */
2584 int __weak ftrace_arch_code_modify_post_process(void)
2585 {
2586         return 0;
2587 }
2588 
2589 void ftrace_modify_all_code(int command)
2590 {
2591         int update = command & FTRACE_UPDATE_TRACE_FUNC;
2592         int err = 0;
2593 
2594         /*
2595          * If the ftrace_caller calls a ftrace_ops func directly,
2596          * we need to make sure that it only traces functions it
2597          * expects to trace. When doing the switch of functions,
2598          * we need to update to the ftrace_ops_list_func first
2599          * before the transition between old and new calls are set,
2600          * as the ftrace_ops_list_func will check the ops hashes
2601          * to make sure the ops are having the right functions
2602          * traced.
2603          */
2604         if (update) {
2605                 err = ftrace_update_ftrace_func(ftrace_ops_list_func);
2606                 if (FTRACE_WARN_ON(err))
2607                         return;
2608         }
2609 
2610         if (command & FTRACE_UPDATE_CALLS)
2611                 ftrace_replace_code(1);
2612         else if (command & FTRACE_DISABLE_CALLS)
2613                 ftrace_replace_code(0);
2614 
2615         if (update && ftrace_trace_function != ftrace_ops_list_func) {
2616                 function_trace_op = set_function_trace_op;
2617                 smp_wmb();
2618                 /* If irqs are disabled, we are in stop machine */
2619                 if (!irqs_disabled())
2620                         smp_call_function(ftrace_sync_ipi, NULL, 1);
2621                 err = ftrace_update_ftrace_func(ftrace_trace_function);
2622                 if (FTRACE_WARN_ON(err))
2623                         return;
2624         }
2625 
2626         if (command & FTRACE_START_FUNC_RET)
2627                 err = ftrace_enable_ftrace_graph_caller();
2628         else if (command & FTRACE_STOP_FUNC_RET)
2629                 err = ftrace_disable_ftrace_graph_caller();
2630         FTRACE_WARN_ON(err);
2631 }
2632 
2633 static int __ftrace_modify_code(void *data)
2634 {
2635         int *command = data;
2636 
2637         ftrace_modify_all_code(*command);
2638 
2639         return 0;
2640 }
2641 
2642 /**
2643  * ftrace_run_stop_machine, go back to the stop machine method
2644  * @command: The command to tell ftrace what to do
2645  *
2646  * If an arch needs to fall back to the stop machine method, the
2647  * it can call this function.
2648  */
2649 void ftrace_run_stop_machine(int command)
2650 {
2651         stop_machine(__ftrace_modify_code, &command, NULL);
2652 }
2653 
2654 /**
2655  * arch_ftrace_update_code, modify the code to trace or not trace
2656  * @command: The command that needs to be done
2657  *
2658  * Archs can override this function if it does not need to
2659  * run stop_machine() to modify code.
2660  */
2661 void __weak arch_ftrace_update_code(int command)
2662 {
2663         ftrace_run_stop_machine(command);
2664 }
2665 
2666 static void ftrace_run_update_code(int command)
2667 {
2668         int ret;
2669 
2670         ret = ftrace_arch_code_modify_prepare();
2671         FTRACE_WARN_ON(ret);
2672         if (ret)
2673                 return;
2674 
2675         /*
2676          * By default we use stop_machine() to modify the code.
2677          * But archs can do what ever they want as long as it
2678          * is safe. The stop_machine() is the safest, but also
2679          * produces the most overhead.
2680          */
2681         arch_ftrace_update_code(command);
2682 
2683         ret = ftrace_arch_code_modify_post_process();
2684         FTRACE_WARN_ON(ret);
2685 }
2686 
2687 static void ftrace_run_modify_code(struct ftrace_ops *ops, int command,
2688                                    struct ftrace_ops_hash *old_hash)
2689 {
2690         ops->flags |= FTRACE_OPS_FL_MODIFYING;
2691         ops->old_hash.filter_hash = old_hash->filter_hash;
2692         ops->old_hash.notrace_hash = old_hash->notrace_hash;
2693         ftrace_run_update_code(command);
2694         ops->old_hash.filter_hash = NULL;
2695         ops->old_hash.notrace_hash = NULL;
2696         ops->flags &= ~FTRACE_OPS_FL_MODIFYING;
2697 }
2698 
2699 static ftrace_func_t saved_ftrace_func;
2700 static int ftrace_start_up;
2701 
2702 void __weak arch_ftrace_trampoline_free(struct ftrace_ops *ops)
2703 {
2704 }
2705 
2706 static void ftrace_startup_enable(int command)
2707 {
2708         if (saved_ftrace_func != ftrace_trace_function) {
2709                 saved_ftrace_func = ftrace_trace_function;
2710                 command |= FTRACE_UPDATE_TRACE_FUNC;
2711         }
2712 
2713         if (!command || !ftrace_enabled)
2714                 return;
2715 
2716         ftrace_run_update_code(command);
2717 }
2718 
2719 static void ftrace_startup_all(int command)
2720 {
2721         update_all_ops = true;
2722         ftrace_startup_enable(command);
2723         update_all_ops = false;
2724 }
2725 
2726 static int ftrace_startup(struct ftrace_ops *ops, int command)
2727 {
2728         int ret;
2729 
2730         if (unlikely(ftrace_disabled))
2731                 return -ENODEV;
2732 
2733         ret = __register_ftrace_function(ops);
2734         if (ret)
2735                 return ret;
2736 
2737         ftrace_start_up++;
2738 
2739         /*
2740          * Note that ftrace probes uses this to start up
2741          * and modify functions it will probe. But we still
2742          * set the ADDING flag for modification, as probes
2743          * do not have trampolines. If they add them in the
2744          * future, then the probes will need to distinguish
2745          * between adding and updating probes.
2746          */
2747         ops->flags |= FTRACE_OPS_FL_ENABLED | FTRACE_OPS_FL_ADDING;
2748 
2749         ret = ftrace_hash_ipmodify_enable(ops);
2750         if (ret < 0) {
2751                 /* Rollback registration process */
2752                 __unregister_ftrace_function(ops);
2753                 ftrace_start_up--;
2754                 ops->flags &= ~FTRACE_OPS_FL_ENABLED;
2755                 return ret;
2756         }
2757 
2758         if (ftrace_hash_rec_enable(ops, 1))
2759                 command |= FTRACE_UPDATE_CALLS;
2760 
2761         ftrace_startup_enable(command);
2762 
2763         ops->flags &= ~FTRACE_OPS_FL_ADDING;
2764 
2765         return 0;
2766 }
2767 
2768 static int ftrace_shutdown(struct ftrace_ops *ops, int command)
2769 {
2770         int ret;
2771 
2772         if (unlikely(ftrace_disabled))
2773                 return -ENODEV;
2774 
2775         ret = __unregister_ftrace_function(ops);
2776         if (ret)
2777                 return ret;
2778 
2779         ftrace_start_up--;
2780         /*
2781          * Just warn in case of unbalance, no need to kill ftrace, it's not
2782          * critical but the ftrace_call callers may be never nopped again after
2783          * further ftrace uses.
2784          */
2785         WARN_ON_ONCE(ftrace_start_up < 0);
2786 
2787         /* Disabling ipmodify never fails */
2788         ftrace_hash_ipmodify_disable(ops);
2789 
2790         if (ftrace_hash_rec_disable(ops, 1))
2791                 command |= FTRACE_UPDATE_CALLS;
2792 
2793         ops->flags &= ~FTRACE_OPS_FL_ENABLED;
2794 
2795         if (saved_ftrace_func != ftrace_trace_function) {
2796                 saved_ftrace_func = ftrace_trace_function;
2797                 command |= FTRACE_UPDATE_TRACE_FUNC;
2798         }
2799 
2800         if (!command || !ftrace_enabled) {
2801                 /*
2802                  * If these are dynamic or per_cpu ops, they still
2803                  * need their data freed. Since, function tracing is
2804                  * not currently active, we can just free them
2805                  * without synchronizing all CPUs.
2806                  */
2807                 if (ops->flags & FTRACE_OPS_FL_DYNAMIC)
2808                         goto free_ops;
2809 
2810                 return 0;
2811         }
2812 
2813         /*
2814          * If the ops uses a trampoline, then it needs to be
2815          * tested first on update.
2816          */
2817         ops->flags |= FTRACE_OPS_FL_REMOVING;
2818         removed_ops = ops;
2819 
2820         /* The trampoline logic checks the old hashes */
2821         ops->old_hash.filter_hash = ops->func_hash->filter_hash;
2822         ops->old_hash.notrace_hash = ops->func_hash->notrace_hash;
2823 
2824         ftrace_run_update_code(command);
2825 
2826         /*
2827          * If there's no more ops registered with ftrace, run a
2828          * sanity check to make sure all rec flags are cleared.
2829          */
2830         if (rcu_dereference_protected(ftrace_ops_list,
2831                         lockdep_is_held(&ftrace_lock)) == &ftrace_list_end) {
2832                 struct ftrace_page *pg;
2833                 struct dyn_ftrace *rec;
2834 
2835                 do_for_each_ftrace_rec(pg, rec) {
2836                         if (FTRACE_WARN_ON_ONCE(rec->flags & ~FTRACE_FL_DISABLED))
2837                                 pr_warn("  %pS flags:%lx\n",
2838                                         (void *)rec->ip, rec->flags);
2839                 } while_for_each_ftrace_rec();
2840         }
2841 
2842         ops->old_hash.filter_hash = NULL;
2843         ops->old_hash.notrace_hash = NULL;
2844 
2845         removed_ops = NULL;
2846         ops->flags &= ~FTRACE_OPS_FL_REMOVING;
2847 
2848         /*
2849          * Dynamic ops may be freed, we must make sure that all
2850          * callers are done before leaving this function.
2851          * The same goes for freeing the per_cpu data of the per_cpu
2852          * ops.
2853          */
2854         if (ops->flags & FTRACE_OPS_FL_DYNAMIC) {
2855                 /*
2856                  * We need to do a hard force of sched synchronization.
2857                  * This is because we use preempt_disable() to do RCU, but
2858                  * the function tracers can be called where RCU is not watching
2859                  * (like before user_exit()). We can not rely on the RCU
2860                  * infrastructure to do the synchronization, thus we must do it
2861                  * ourselves.
2862                  */
2863                 schedule_on_each_cpu(ftrace_sync);
2864 
2865                 /*
2866                  * When the kernel is preeptive, tasks can be preempted
2867                  * while on a ftrace trampoline. Just scheduling a task on
2868                  * a CPU is not good enough to flush them. Calling
2869                  * synchornize_rcu_tasks() will wait for those tasks to
2870                  * execute and either schedule voluntarily or enter user space.
2871                  */
2872                 if (IS_ENABLED(CONFIG_PREEMPT))
2873                         synchronize_rcu_tasks();
2874 
2875  free_ops:
2876                 arch_ftrace_trampoline_free(ops);
2877         }
2878 
2879         return 0;
2880 }
2881 
2882 static void ftrace_startup_sysctl(void)
2883 {
2884         int command;
2885 
2886         if (unlikely(ftrace_disabled))
2887                 return;
2888 
2889         /* Force update next time */
2890         saved_ftrace_func = NULL;
2891         /* ftrace_start_up is true if we want ftrace running */
2892         if (ftrace_start_up) {
2893                 command = FTRACE_UPDATE_CALLS;
2894                 if (ftrace_graph_active)
2895                         command |= FTRACE_START_FUNC_RET;
2896                 ftrace_startup_enable(command);
2897         }
2898 }
2899 
2900 static void ftrace_shutdown_sysctl(void)
2901 {
2902         int command;
2903 
2904         if (unlikely(ftrace_disabled))
2905                 return;
2906 
2907         /* ftrace_start_up is true if ftrace is running */
2908         if (ftrace_start_up) {
2909                 command = FTRACE_DISABLE_CALLS;
2910                 if (ftrace_graph_active)
2911                         command |= FTRACE_STOP_FUNC_RET;
2912                 ftrace_run_update_code(command);
2913         }
2914 }
2915 
2916 static u64              ftrace_update_time;
2917 unsigned long           ftrace_update_tot_cnt;
2918 
2919 static inline int ops_traces_mod(struct ftrace_ops *ops)
2920 {
2921         /*
2922          * Filter_hash being empty will default to trace module.
2923          * But notrace hash requires a test of individual module functions.
2924          */
2925         return ftrace_hash_empty(ops->func_hash->filter_hash) &&
2926                 ftrace_hash_empty(ops->func_hash->notrace_hash);
2927 }
2928 
2929 /*
2930  * Check if the current ops references the record.
2931  *
2932  * If the ops traces all functions, then it was already accounted for.
2933  * If the ops does not trace the current record function, skip it.
2934  * If the ops ignores the function via notrace filter, skip it.
2935  */
2936 static inline bool
2937 ops_references_rec(struct ftrace_ops *ops, struct dyn_ftrace *rec)
2938 {
2939         /* If ops isn't enabled, ignore it */
2940         if (!(ops->flags & FTRACE_OPS_FL_ENABLED))
2941                 return 0;
2942 
2943         /* If ops traces all then it includes this function */
2944         if (ops_traces_mod(ops))
2945                 return 1;
2946 
2947         /* The function must be in the filter */
2948         if (!ftrace_hash_empty(ops->func_hash->filter_hash) &&
2949             !__ftrace_lookup_ip(ops->func_hash->filter_hash, rec->ip))
2950                 return 0;
2951 
2952         /* If in notrace hash, we ignore it too */
2953         if (ftrace_lookup_ip(ops->func_hash->notrace_hash, rec->ip))
2954                 return 0;
2955 
2956         return 1;
2957 }
2958 
2959 static int ftrace_update_code(struct module *mod, struct ftrace_page *new_pgs)
2960 {
2961         struct ftrace_page *pg;
2962         struct dyn_ftrace *p;
2963         u64 start, stop;
2964         unsigned long update_cnt = 0;
2965         unsigned long rec_flags = 0;
2966         int i;
2967 
2968         start = ftrace_now(raw_smp_processor_id());
2969 
2970         /*
2971          * When a module is loaded, this function is called to convert
2972          * the calls to mcount in its text to nops, and also to create
2973          * an entry in the ftrace data. Now, if ftrace is activated
2974          * after this call, but before the module sets its text to
2975          * read-only, the modification of enabling ftrace can fail if
2976          * the read-only is done while ftrace is converting the calls.
2977          * To prevent this, the module's records are set as disabled
2978          * and will be enabled after the call to set the module's text
2979          * to read-only.
2980          */
2981         if (mod)
2982                 rec_flags |= FTRACE_FL_DISABLED;
2983 
2984         for (pg = new_pgs; pg; pg = pg->next) {
2985 
2986                 for (i = 0; i < pg->index; i++) {
2987 
2988                         /* If something went wrong, bail without enabling anything */
2989                         if (unlikely(ftrace_disabled))
2990                                 return -1;
2991 
2992                         p = &pg->records[i];
2993                         p->flags = rec_flags;
2994 
2995                         /*
2996                          * Do the initial record conversion from mcount jump
2997                          * to the NOP instructions.
2998                          */
2999                         if (!ftrace_code_disable(mod, p))
3000                                 break;
3001 
3002                         update_cnt++;
3003                 }
3004         }
3005 
3006         stop = ftrace_now(raw_smp_processor_id());
3007         ftrace_update_time = stop - start;
3008         ftrace_update_tot_cnt += update_cnt;
3009 
3010         return 0;
3011 }
3012 
3013 static int ftrace_allocate_records(struct ftrace_page *pg, int count)
3014 {
3015         int order;
3016         int cnt;
3017 
3018         if (WARN_ON(!count))
3019                 return -EINVAL;
3020 
3021         order = get_count_order(DIV_ROUND_UP(count, ENTRIES_PER_PAGE));
3022 
3023         /*
3024          * We want to fill as much as possible. No more than a page
3025          * may be empty.
3026          */
3027         while ((PAGE_SIZE << order) / ENTRY_SIZE >= count + ENTRIES_PER_PAGE)
3028                 order--;
3029 
3030  again:
3031         pg->records = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, order);
3032 
3033         if (!pg->records) {
3034                 /* if we can't allocate this size, try something smaller */
3035                 if (!order)
3036                         return -ENOMEM;
3037                 order >>= 1;
3038                 goto again;
3039         }
3040 
3041         cnt = (PAGE_SIZE << order) / ENTRY_SIZE;
3042         pg->size = cnt;
3043 
3044         if (cnt > count)
3045                 cnt = count;
3046 
3047         return cnt;
3048 }
3049 
3050 static struct ftrace_page *
3051 ftrace_allocate_pages(unsigned long num_to_init)
3052 {
3053         struct ftrace_page *start_pg;
3054         struct ftrace_page *pg;
3055         int order;
3056         int cnt;
3057 
3058         if (!num_to_init)
3059                 return 0;
3060 
3061         start_pg = pg = kzalloc(sizeof(*pg), GFP_KERNEL);
3062         if (!pg)
3063                 return NULL;
3064 
3065         /*
3066          * Try to allocate as much as possible in one continues
3067          * location that fills in all of the space. We want to
3068          * waste as little space as possible.
3069          */
3070         for (;;) {
3071                 cnt = ftrace_allocate_records(pg, num_to_init);
3072                 if (cnt < 0)
3073                         goto free_pages;
3074 
3075                 num_to_init -= cnt;
3076                 if (!num_to_init)
3077                         break;
3078 
3079                 pg->next = kzalloc(sizeof(*pg), GFP_KERNEL);
3080                 if (!pg->next)
3081                         goto free_pages;
3082 
3083                 pg = pg->next;
3084         }
3085 
3086         return start_pg;
3087 
3088  free_pages:
3089         pg = start_pg;
3090         while (pg) {
3091                 order = get_count_order(pg->size / ENTRIES_PER_PAGE);
3092                 free_pages((unsigned long)pg->records, order);
3093                 start_pg = pg->next;
3094                 kfree(pg);
3095                 pg = start_pg;
3096         }
3097         pr_info("ftrace: FAILED to allocate memory for functions\n");
3098         return NULL;
3099 }
3100 
3101 #define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */
3102 
3103 struct ftrace_iterator {
3104         loff_t                          pos;
3105         loff_t                          func_pos;
3106         loff_t                          mod_pos;
3107         struct ftrace_page              *pg;
3108         struct dyn_ftrace               *func;
3109         struct ftrace_func_probe        *probe;
3110         struct ftrace_func_entry        *probe_entry;
3111         struct trace_parser             parser;
3112         struct ftrace_hash              *hash;
3113         struct ftrace_ops               *ops;
3114         struct trace_array              *tr;
3115         struct list_head                *mod_list;
3116         int                             pidx;
3117         int                             idx;
3118         unsigned                        flags;
3119 };
3120 
3121 static void *
3122 t_probe_next(struct seq_file *m, loff_t *pos)
3123 {
3124         struct ftrace_iterator *iter = m->private;
3125         struct trace_array *tr = iter->ops->private;
3126         struct list_head *func_probes;
3127         struct ftrace_hash *hash;
3128         struct list_head *next;
3129         struct hlist_node *hnd = NULL;
3130         struct hlist_head *hhd;
3131         int size;
3132 
3133         (*pos)++;
3134         iter->pos = *pos;
3135 
3136         if (!tr)
3137                 return NULL;
3138 
3139         func_probes = &tr->func_probes;
3140         if (list_empty(func_probes))
3141                 return NULL;
3142 
3143         if (!iter->probe) {
3144                 next = func_probes->next;
3145                 iter->probe = list_entry(next, struct ftrace_func_probe, list);
3146         }
3147 
3148         if (iter->probe_entry)
3149                 hnd = &iter->probe_entry->hlist;
3150 
3151         hash = iter->probe->ops.func_hash->filter_hash;
3152         size = 1 << hash->size_bits;
3153 
3154  retry:
3155         if (iter->pidx >= size) {
3156                 if (iter->probe->list.next == func_probes)
3157                         return NULL;
3158                 next = iter->probe->list.next;
3159                 iter->probe = list_entry(next, struct ftrace_func_probe, list);
3160                 hash = iter->probe->ops.func_hash->filter_hash;
3161                 size = 1 << hash->size_bits;
3162                 iter->pidx = 0;
3163         }
3164 
3165         hhd = &hash->buckets[iter->pidx];
3166 
3167         if (hlist_empty(hhd)) {
3168                 iter->pidx++;
3169                 hnd = NULL;
3170                 goto retry;
3171         }
3172 
3173         if (!hnd)
3174                 hnd = hhd->first;
3175         else {
3176                 hnd = hnd->next;
3177                 if (!hnd) {
3178                         iter->pidx++;
3179                         goto retry;
3180                 }
3181         }
3182 
3183         if (WARN_ON_ONCE(!hnd))
3184                 return NULL;
3185 
3186         iter->probe_entry = hlist_entry(hnd, struct ftrace_func_entry, hlist);
3187 
3188         return iter;
3189 }
3190 
3191 static void *t_probe_start(struct seq_file *m, loff_t *pos)
3192 {
3193         struct ftrace_iterator *iter = m->private;
3194         void *p = NULL;
3195         loff_t l;
3196 
3197         if (!(iter->flags & FTRACE_ITER_DO_PROBES))
3198                 return NULL;
3199 
3200         if (iter->mod_pos > *pos)
3201                 return NULL;
3202 
3203         iter->probe = NULL;
3204         iter->probe_entry = NULL;
3205         iter->pidx = 0;
3206         for (l = 0; l <= (*pos - iter->mod_pos); ) {
3207                 p = t_probe_next(m, &l);
3208                 if (!p)
3209                         break;
3210         }
3211         if (!p)
3212                 return NULL;
3213 
3214         /* Only set this if we have an item */
3215         iter->flags |= FTRACE_ITER_PROBE;
3216 
3217         return iter;
3218 }
3219 
3220 static int
3221 t_probe_show(struct seq_file *m, struct ftrace_iterator *iter)
3222 {
3223         struct ftrace_func_entry *probe_entry;
3224         struct ftrace_probe_ops *probe_ops;
3225         struct ftrace_func_probe *probe;
3226 
3227         probe = iter->probe;
3228         probe_entry = iter->probe_entry;
3229 
3230         if (WARN_ON_ONCE(!probe || !probe_entry))
3231                 return -EIO;
3232 
3233         probe_ops = probe->probe_ops;
3234 
3235         if (probe_ops->print)
3236                 return probe_ops->print(m, probe_entry->ip, probe_ops, probe->data);
3237 
3238         seq_printf(m, "%ps:%ps\n", (void *)probe_entry->ip,
3239                    (void *)probe_ops->func);
3240 
3241         return 0;
3242 }
3243 
3244 static void *
3245 t_mod_next(struct seq_file *m, loff_t *pos)
3246 {
3247         struct ftrace_iterator *iter = m->private;
3248         struct trace_array *tr = iter->tr;
3249 
3250         (*pos)++;
3251         iter->pos = *pos;
3252 
3253         iter->mod_list = iter->mod_list->next;
3254 
3255         if (iter->mod_list == &tr->mod_trace ||
3256             iter->mod_list == &tr->mod_notrace) {
3257                 iter->flags &= ~FTRACE_ITER_MOD;
3258                 return NULL;
3259         }
3260 
3261         iter->mod_pos = *pos;
3262 
3263         return iter;
3264 }
3265 
3266 static void *t_mod_start(struct seq_file *m, loff_t *pos)
3267 {
3268         struct ftrace_iterator *iter = m->private;
3269         void *p = NULL;
3270         loff_t l;
3271 
3272         if (iter->func_pos > *pos)
3273                 return NULL;
3274 
3275         iter->mod_pos = iter->func_pos;
3276 
3277         /* probes are only available if tr is set */
3278         if (!iter->tr)
3279                 return NULL;
3280 
3281         for (l = 0; l <= (*pos - iter->func_pos); ) {
3282                 p = t_mod_next(m, &l);
3283                 if (!p)
3284                         break;
3285         }
3286         if (!p) {
3287                 iter->flags &= ~FTRACE_ITER_MOD;
3288                 return t_probe_start(m, pos);
3289         }
3290 
3291         /* Only set this if we have an item */
3292         iter->flags |= FTRACE_ITER_MOD;
3293 
3294         return iter;
3295 }
3296 
3297 static int
3298 t_mod_show(struct seq_file *m, struct ftrace_iterator *iter)
3299 {
3300         struct ftrace_mod_load *ftrace_mod;
3301         struct trace_array *tr = iter->tr;
3302 
3303         if (WARN_ON_ONCE(!iter->mod_list) ||
3304                          iter->mod_list == &tr->mod_trace ||
3305                          iter->mod_list == &tr->mod_notrace)
3306                 return -EIO;
3307 
3308         ftrace_mod = list_entry(iter->mod_list, struct ftrace_mod_load, list);
3309 
3310         if (ftrace_mod->func)
3311                 seq_printf(m, "%s", ftrace_mod->func);
3312         else
3313                 seq_putc(m, '*');
3314 
3315         seq_printf(m, ":mod:%s\n", ftrace_mod->module);
3316 
3317         return 0;
3318 }
3319 
3320 static void *
3321 t_func_next(struct seq_file *m, loff_t *pos)
3322 {
3323         struct ftrace_iterator *iter = m->private;
3324         struct dyn_ftrace *rec = NULL;
3325 
3326         (*pos)++;
3327 
3328  retry:
3329         if (iter->idx >= iter->pg->index) {
3330                 if (iter->pg->next) {
3331                         iter->pg = iter->pg->next;
3332                         iter->idx = 0;
3333                         goto retry;
3334                 }
3335         } else {
3336                 rec = &iter->pg->records[iter->idx++];
3337                 if (((iter->flags & (FTRACE_ITER_FILTER | FTRACE_ITER_NOTRACE)) &&
3338                      !ftrace_lookup_ip(iter->hash, rec->ip)) ||
3339 
3340                     ((iter->flags & FTRACE_ITER_ENABLED) &&
3341                      !(rec->flags & FTRACE_FL_ENABLED))) {
3342 
3343                         rec = NULL;
3344                         goto retry;
3345                 }
3346         }
3347 
3348         if (!rec)
3349                 return NULL;
3350 
3351         iter->pos = iter->func_pos = *pos;
3352         iter->func = rec;
3353 
3354         return iter;
3355 }
3356 
3357 static void *
3358 t_next(struct seq_file *m, void *v, loff_t *pos)
3359 {
3360         struct ftrace_iterator *iter = m->private;
3361         loff_t l = *pos; /* t_probe_start() must use original pos */
3362         void *ret;
3363 
3364         if (unlikely(ftrace_disabled))
3365                 return NULL;
3366 
3367         if (iter->flags & FTRACE_ITER_PROBE)
3368                 return t_probe_next(m, pos);
3369 
3370         if (iter->flags & FTRACE_ITER_MOD)
3371                 return t_mod_next(m, pos);
3372 
3373         if (iter->flags & FTRACE_ITER_PRINTALL) {
3374                 /* next must increment pos, and t_probe_start does not */
3375                 (*pos)++;
3376                 return t_mod_start(m, &l);
3377         }
3378 
3379         ret = t_func_next(m, pos);
3380 
3381         if (!ret)
3382                 return t_mod_start(m, &l);
3383 
3384         return ret;
3385 }
3386 
3387 static void reset_iter_read(struct ftrace_iterator *iter)
3388 {
3389         iter->pos = 0;
3390         iter->func_pos = 0;
3391         iter->flags &= ~(FTRACE_ITER_PRINTALL | FTRACE_ITER_PROBE | FTRACE_ITER_MOD);
3392 }
3393 
3394 static void *t_start(struct seq_file *m, loff_t *pos)
3395 {
3396         struct ftrace_iterator *iter = m->private;
3397         void *p = NULL;
3398         loff_t l;
3399 
3400         mutex_lock(&ftrace_lock);
3401 
3402         if (unlikely(ftrace_disabled))
3403                 return NULL;
3404 
3405         /*
3406          * If an lseek was done, then reset and start from beginning.
3407          */
3408         if (*pos < iter->pos)
3409                 reset_iter_read(iter);
3410 
3411         /*
3412          * For set_ftrace_filter reading, if we have the filter
3413          * off, we can short cut and just print out that all
3414          * functions are enabled.
3415          */
3416         if ((iter->flags & (FTRACE_ITER_FILTER | FTRACE_ITER_NOTRACE)) &&
3417             ftrace_hash_empty(iter->hash)) {
3418                 iter->func_pos = 1; /* Account for the message */
3419                 if (*pos > 0)
3420                         return t_mod_start(m, pos);
3421                 iter->flags |= FTRACE_ITER_PRINTALL;
3422                 /* reset in case of seek/pread */
3423                 iter->flags &= ~FTRACE_ITER_PROBE;
3424                 return iter;
3425         }
3426 
3427         if (iter->flags & FTRACE_ITER_MOD)
3428                 return t_mod_start(m, pos);
3429 
3430         /*
3431          * Unfortunately, we need to restart at ftrace_pages_start
3432          * every time we let go of the ftrace_mutex. This is because
3433          * those pointers can change without the lock.
3434          */
3435         iter->pg = ftrace_pages_start;
3436         iter->idx = 0;
3437         for (l = 0; l <= *pos; ) {
3438                 p = t_func_next(m, &l);
3439                 if (!p)
3440                         break;
3441         }
3442 
3443         if (!p)
3444                 return t_mod_start(m, pos);
3445 
3446         return iter;
3447 }
3448 
3449 static void t_stop(struct seq_file *m, void *p)
3450 {
3451         mutex_unlock(&ftrace_lock);
3452 }
3453 
3454 void * __weak
3455 arch_ftrace_trampoline_func(struct ftrace_ops *ops, struct dyn_ftrace *rec)
3456 {
3457         return NULL;
3458 }
3459 
3460 static void add_trampoline_func(struct seq_file *m, struct ftrace_ops *ops,
3461                                 struct dyn_ftrace *rec)
3462 {
3463         void *ptr;
3464 
3465         ptr = arch_ftrace_trampoline_func(ops, rec);
3466         if (ptr)
3467                 seq_printf(m, " ->%pS", ptr);
3468 }
3469 
3470 static int t_show(struct seq_file *m, void *v)
3471 {
3472         struct ftrace_iterator *iter = m->private;
3473         struct dyn_ftrace *rec;
3474 
3475         if (iter->flags & FTRACE_ITER_PROBE)
3476                 return t_probe_show(m, iter);
3477 
3478         if (iter->flags & FTRACE_ITER_MOD)
3479                 return t_mod_show(m, iter);
3480 
3481         if (iter->flags & FTRACE_ITER_PRINTALL) {
3482                 if (iter->flags & FTRACE_ITER_NOTRACE)
3483                         seq_puts(m, "#### no functions disabled ####\n");
3484                 else
3485                         seq_puts(m, "#### all functions enabled ####\n");
3486                 return 0;
3487         }
3488 
3489         rec = iter->func;
3490 
3491         if (!rec)
3492                 return 0;
3493 
3494         seq_printf(m, "%ps", (void *)rec->ip);
3495         if (iter->flags & FTRACE_ITER_ENABLED) {
3496                 struct ftrace_ops *ops;
3497 
3498                 seq_printf(m, " (%ld)%s%s",
3499                            ftrace_rec_count(rec),
3500                            rec->flags & FTRACE_FL_REGS ? " R" : "  ",
3501                            rec->flags & FTRACE_FL_IPMODIFY ? " I" : "  ");
3502                 if (rec->flags & FTRACE_FL_TRAMP_EN) {
3503                         ops = ftrace_find_tramp_ops_any(rec);
3504                         if (ops) {
3505                                 do {
3506                                         seq_printf(m, "\ttramp: %pS (%pS)",
3507                                                    (void *)ops->trampoline,
3508                                                    (void *)ops->func);
3509                                         add_trampoline_func(m, ops, rec);
3510                                         ops = ftrace_find_tramp_ops_next(rec, ops);
3511                                 } while (ops);
3512                         } else
3513                                 seq_puts(m, "\ttramp: ERROR!");
3514                 } else {
3515                         add_trampoline_func(m, NULL, rec);
3516                 }
3517         }       
3518 
3519         seq_putc(m, '\n');
3520 
3521         return 0;
3522 }
3523 
3524 static const struct seq_operations show_ftrace_seq_ops = {
3525         .start = t_start,
3526         .next = t_next,
3527         .stop = t_stop,
3528         .show = t_show,
3529 };
3530 
3531 static int
3532 ftrace_avail_open(struct inode *inode, struct file *file)
3533 {
3534         struct ftrace_iterator *iter;
3535 
3536         if (unlikely(ftrace_disabled))
3537                 return -ENODEV;
3538 
3539         iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter));
3540         if (!iter)
3541                 return -ENOMEM;
3542 
3543         iter->pg = ftrace_pages_start;
3544         iter->ops = &global_ops;
3545 
3546         return 0;
3547 }
3548 
3549 static int
3550 ftrace_enabled_open(struct inode *inode, struct file *file)
3551 {
3552         struct ftrace_iterator *iter;
3553 
3554         iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter));
3555         if (!iter)
3556                 return -ENOMEM;
3557 
3558         iter->pg = ftrace_pages_start;
3559         iter->flags = FTRACE_ITER_ENABLED;
3560         iter->ops = &global_ops;
3561 
3562         return 0;
3563 }
3564 
3565 /**
3566  * ftrace_regex_open - initialize function tracer filter files
3567  * @ops: The ftrace_ops that hold the hash filters
3568  * @flag: The type of filter to process
3569  * @inode: The inode, usually passed in to your open routine
3570  * @file: The file, usually passed in to your open routine
3571  *
3572  * ftrace_regex_open() initializes the filter files for the
3573  * @ops. Depending on @flag it may process the filter hash or
3574  * the notrace hash of @ops. With this called from the open
3575  * routine, you can use ftrace_filter_write() for the write
3576  * routine if @flag has FTRACE_ITER_FILTER set, or
3577  * ftrace_notrace_write() if @flag has FTRACE_ITER_NOTRACE set.
3578  * tracing_lseek() should be used as the lseek routine, and
3579  * release must call ftrace_regex_release().
3580  */
3581 int
3582 ftrace_regex_open(struct ftrace_ops *ops, int flag,
3583                   struct inode *inode, struct file *file)
3584 {
3585         struct ftrace_iterator *iter;
3586         struct ftrace_hash *hash;
3587         struct list_head *mod_head;
3588         struct trace_array *tr = ops->private;
3589         int ret = 0;
3590 
3591         ftrace_ops_init(ops);
3592 
3593         if (unlikely(ftrace_disabled))
3594                 return -ENODEV;
3595 
3596         iter = kzalloc(sizeof(*iter), GFP_KERNEL);
3597         if (!iter)
3598                 return -ENOMEM;
3599 
3600         if (trace_parser_get_init(&iter->parser, FTRACE_BUFF_MAX)) {
3601                 kfree(iter);
3602                 return -ENOMEM;
3603         }
3604 
3605         iter->ops = ops;
3606         iter->flags = flag;
3607         iter->tr = tr;
3608 
3609         mutex_lock(&ops->func_hash->regex_lock);
3610 
3611         if (flag & FTRACE_ITER_NOTRACE) {
3612                 hash = ops->func_hash->notrace_hash;
3613                 mod_head = tr ? &tr->mod_notrace : NULL;
3614         } else {
3615                 hash = ops->func_hash->filter_hash;
3616                 mod_head = tr ? &tr->mod_trace : NULL;
3617         }
3618 
3619         iter->mod_list = mod_head;
3620 
3621         if (file->f_mode & FMODE_WRITE) {
3622                 const int size_bits = FTRACE_HASH_DEFAULT_BITS;
3623 
3624                 if (file->f_flags & O_TRUNC) {
3625                         iter->hash = alloc_ftrace_hash(size_bits);
3626                         clear_ftrace_mod_list(mod_head);
3627                 } else {
3628                         iter->hash = alloc_and_copy_ftrace_hash(size_bits, hash);
3629                 }
3630 
3631                 if (!iter->hash) {
3632                         trace_parser_put(&iter->parser);
3633                         kfree(iter);
3634                         ret = -ENOMEM;
3635                         goto out_unlock;
3636                 }
3637         } else
3638                 iter->hash = hash;
3639 
3640         if (file->f_mode & FMODE_READ) {
3641                 iter->pg = ftrace_pages_start;
3642 
3643                 ret = seq_open(file, &show_ftrace_seq_ops);
3644                 if (!ret) {
3645                         struct seq_file *m = file->private_data;
3646                         m->private = iter;
3647                 } else {
3648                         /* Failed */
3649                         free_ftrace_hash(iter->hash);
3650                         trace_parser_put(&iter->parser);
3651                         kfree(iter);
3652                 }
3653         } else
3654                 file->private_data = iter;
3655 
3656  out_unlock:
3657         mutex_unlock(&ops->func_hash->regex_lock);
3658 
3659         return ret;
3660 }
3661 
3662 static int
3663 ftrace_filter_open(struct inode *inode, struct file *file)
3664 {
3665         struct ftrace_ops *ops = inode->i_private;
3666 
3667         return ftrace_regex_open(ops,
3668                         FTRACE_ITER_FILTER | FTRACE_ITER_DO_PROBES,
3669                         inode, file);
3670 }
3671 
3672 static int
3673 ftrace_notrace_open(struct inode *inode, struct file *file)
3674 {
3675         struct ftrace_ops *ops = inode->i_private;
3676 
3677         return ftrace_regex_open(ops, FTRACE_ITER_NOTRACE,
3678                                  inode, file);
3679 }
3680 
3681 /* Type for quick search ftrace basic regexes (globs) from filter_parse_regex */
3682 struct ftrace_glob {
3683         char *search;
3684         unsigned len;
3685         int type;
3686 };
3687 
3688 /*
3689  * If symbols in an architecture don't correspond exactly to the user-visible
3690  * name of what they represent, it is possible to define this function to
3691  * perform the necessary adjustments.
3692 */
3693 char * __weak arch_ftrace_match_adjust(char *str, const char *search)
3694 {
3695         return str;
3696 }
3697 
3698 static int ftrace_match(char *str, struct ftrace_glob *g)
3699 {
3700         int matched = 0;
3701         int slen;
3702 
3703         str = arch_ftrace_match_adjust(str, g->search);
3704 
3705         switch (g->type) {
3706         case MATCH_FULL:
3707                 if (strcmp(str, g->search) == 0)
3708                         matched = 1;
3709                 break;
3710         case MATCH_FRONT_ONLY:
3711                 if (strncmp(str, g->search, g->len) == 0)
3712                         matched = 1;
3713                 break;
3714         case MATCH_MIDDLE_ONLY:
3715                 if (strstr(str, g->search))
3716                         matched = 1;
3717                 break;
3718         case MATCH_END_ONLY:
3719                 slen = strlen(str);
3720                 if (slen >= g->len &&
3721                     memcmp(str + slen - g->len, g->search, g->len) == 0)
3722                         matched = 1;
3723                 break;
3724         case MATCH_GLOB:
3725                 if (glob_match(g->search, str))
3726                         matched = 1;
3727                 break;
3728         }
3729 
3730         return matched;
3731 }
3732 
3733 static int
3734 enter_record(struct ftrace_hash *hash, struct dyn_ftrace *rec, int clear_filter)
3735 {
3736         struct ftrace_func_entry *entry;
3737         int ret = 0;
3738 
3739         entry = ftrace_lookup_ip(hash, rec->ip);
3740         if (clear_filter) {
3741                 /* Do nothing if it doesn't exist */
3742                 if (!entry)
3743                         return 0;
3744 
3745                 free_hash_entry(hash, entry);
3746         } else {
3747                 /* Do nothing if it exists */
3748                 if (entry)
3749                         return 0;
3750 
3751                 ret = add_hash_entry(hash, rec->ip);
3752         }
3753         return ret;
3754 }
3755 
3756 static int
3757 ftrace_match_record(struct dyn_ftrace *rec, struct ftrace_glob *func_g,
3758                 struct ftrace_glob *mod_g, int exclude_mod)
3759 {
3760         char str[KSYM_SYMBOL_LEN];
3761         char *modname;
3762 
3763         kallsyms_lookup(rec->ip, NULL, NULL, &modname, str);
3764 
3765         if (mod_g) {
3766                 int mod_matches = (modname) ? ftrace_match(modname, mod_g) : 0;
3767 
3768                 /* blank module name to match all modules */
3769                 if (!mod_g->len) {
3770                         /* blank module globbing: modname xor exclude_mod */
3771                         if (!exclude_mod != !modname)
3772                                 goto func_match;
3773                         return 0;
3774                 }
3775 
3776                 /*
3777                  * exclude_mod is set to trace everything but the given
3778                  * module. If it is set and the module matches, then
3779                  * return 0. If it is not set, and the module doesn't match
3780                  * also return 0. Otherwise, check the function to see if
3781                  * that matches.
3782                  */
3783                 if (!mod_matches == !exclude_mod)
3784                         return 0;
3785 func_match:
3786                 /* blank search means to match all funcs in the mod */
3787                 if (!func_g->len)
3788                         return 1;
3789         }
3790 
3791         return ftrace_match(str, func_g);
3792 }
3793 
3794 static int
3795 match_records(struct ftrace_hash *hash, char *func, int len, char *mod)
3796 {
3797         struct ftrace_page *pg;
3798         struct dyn_ftrace *rec;
3799         struct ftrace_glob func_g = { .type = MATCH_FULL };
3800         struct ftrace_glob mod_g = { .type = MATCH_FULL };
3801         struct ftrace_glob *mod_match = (mod) ? &mod_g : NULL;
3802         int exclude_mod = 0;
3803         int found = 0;
3804         int ret;
3805         int clear_filter = 0;
3806 
3807         if (func) {
3808                 func_g.type = filter_parse_regex(func, len, &func_g.search,
3809                                                  &clear_filter);
3810                 func_g.len = strlen(func_g.search);
3811         }
3812 
3813         if (mod) {
3814                 mod_g.type = filter_parse_regex(mod, strlen(mod),
3815                                 &mod_g.search, &exclude_mod);
3816                 mod_g.len = strlen(mod_g.search);
3817         }
3818 
3819         mutex_lock(&ftrace_lock);
3820 
3821         if (unlikely(ftrace_disabled))
3822                 goto out_unlock;
3823 
3824         do_for_each_ftrace_rec(pg, rec) {
3825 
3826                 if (rec->flags & FTRACE_FL_DISABLED)
3827                         continue;
3828 
3829                 if (ftrace_match_record(rec, &func_g, mod_match, exclude_mod)) {
3830                         ret = enter_record(hash, rec, clear_filter);
3831                         if (ret < 0) {
3832                                 found = ret;
3833                                 goto out_unlock;
3834                         }
3835                         found = 1;
3836                 }
3837         } while_for_each_ftrace_rec();
3838  out_unlock:
3839         mutex_unlock(&ftrace_lock);
3840 
3841         return found;
3842 }
3843 
3844 static int
3845 ftrace_match_records(struct ftrace_hash *hash, char *buff, int len)
3846 {
3847         return match_records(hash, buff, len, NULL);
3848 }
3849 
3850 static void ftrace_ops_update_code(struct ftrace_ops *ops,
3851                                    struct ftrace_ops_hash *old_hash)
3852 {
3853         struct ftrace_ops *op;
3854 
3855         if (!ftrace_enabled)
3856                 return;
3857 
3858         if (ops->flags & FTRACE_OPS_FL_ENABLED) {
3859                 ftrace_run_modify_code(ops, FTRACE_UPDATE_CALLS, old_hash);
3860                 return;
3861         }
3862 
3863         /*
3864          * If this is the shared global_ops filter, then we need to
3865          * check if there is another ops that shares it, is enabled.
3866          * If so, we still need to run the modify code.
3867          */
3868         if (ops->func_hash != &global_ops.local_hash)
3869                 return;
3870 
3871         do_for_each_ftrace_op(op, ftrace_ops_list) {
3872                 if (op->func_hash == &global_ops.local_hash &&
3873                     op->flags & FTRACE_OPS_FL_ENABLED) {
3874                         ftrace_run_modify_code(op, FTRACE_UPDATE_CALLS, old_hash);
3875                         /* Only need to do this once */
3876                         return;
3877                 }
3878         } while_for_each_ftrace_op(op);
3879 }
3880 
3881 static int ftrace_hash_move_and_update_ops(struct ftrace_ops *ops,
3882                                            struct ftrace_hash **orig_hash,
3883                                            struct ftrace_hash *hash,
3884                                            int enable)
3885 {
3886         struct ftrace_ops_hash old_hash_ops;
3887         struct ftrace_hash *old_hash;
3888         int ret;
3889 
3890         old_hash = *orig_hash;
3891         old_hash_ops.filter_hash = ops->func_hash->filter_hash;
3892         old_hash_ops.notrace_hash = ops->func_hash->notrace_hash;
3893         ret = ftrace_hash_move(ops, enable, orig_hash, hash);
3894         if (!ret) {
3895                 ftrace_ops_update_code(ops, &old_hash_ops);
3896                 free_ftrace_hash_rcu(old_hash);
3897         }
3898         return ret;
3899 }
3900 
3901 static bool module_exists(const char *module)
3902 {
3903         /* All modules have the symbol __this_module */
3904         const char this_mod[] = "__this_module";
3905         char modname[MAX_PARAM_PREFIX_LEN + sizeof(this_mod) + 2];
3906         unsigned long val;
3907         int n;
3908 
3909         n = snprintf(modname, sizeof(modname), "%s:%s", module, this_mod);
3910 
3911         if (n > sizeof(modname) - 1)
3912                 return false;
3913 
3914         val = module_kallsyms_lookup_name(modname);
3915         return val != 0;
3916 }
3917 
3918 static int cache_mod(struct trace_array *tr,
3919                      const char *func, char *module, int enable)
3920 {
3921         struct ftrace_mod_load *ftrace_mod, *n;
3922         struct list_head *head = enable ? &tr->mod_trace : &tr->mod_notrace;
3923         int ret;
3924 
3925         mutex_lock(&ftrace_lock);
3926 
3927         /* We do not cache inverse filters */
3928         if (func[0] == '!') {
3929                 func++;
3930                 ret = -EINVAL;
3931 
3932                 /* Look to remove this hash */
3933                 list_for_each_entry_safe(ftrace_mod, n, head, list) {
3934                         if (strcmp(ftrace_mod->module, module) != 0)
3935                                 continue;
3936 
3937                         /* no func matches all */
3938                         if (strcmp(func, "*") == 0 ||
3939                             (ftrace_mod->func &&
3940                              strcmp(ftrace_mod->func, func) == 0)) {
3941                                 ret = 0;
3942                                 free_ftrace_mod(ftrace_mod);
3943                                 continue;
3944                         }
3945                 }
3946                 goto out;
3947         }
3948 
3949         ret = -EINVAL;
3950         /* We only care about modules that have not been loaded yet */
3951         if (module_exists(module))
3952                 goto out;
3953 
3954         /* Save this string off, and execute it when the module is loaded */
3955         ret = ftrace_add_mod(tr, func, module, enable);
3956  out:
3957         mutex_unlock(&ftrace_lock);
3958 
3959         return ret;
3960 }
3961 
3962 static int
3963 ftrace_set_regex(struct ftrace_ops *ops, unsigned char *buf, int len,
3964                  int reset, int enable);
3965 
3966 #ifdef CONFIG_MODULES
3967 static void process_mod_list(struct list_head *head, struct ftrace_ops *ops,
3968                              char *mod, bool enable)
3969 {
3970         struct ftrace_mod_load *ftrace_mod, *n;
3971         struct ftrace_hash **orig_hash, *new_hash;
3972         LIST_HEAD(process_mods);
3973         char *func;
3974         int ret;
3975 
3976         mutex_lock(&ops->func_hash->regex_lock);
3977 
3978         if (enable)
3979                 orig_hash = &ops->func_hash->filter_hash;
3980         else
3981                 orig_hash = &ops->func_hash->notrace_hash;
3982 
3983         new_hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS,
3984                                               *orig_hash);
3985         if (!new_hash)
3986                 goto out; /* warn? */
3987 
3988         mutex_lock(&ftrace_lock);
3989 
3990         list_for_each_entry_safe(ftrace_mod, n, head, list) {
3991 
3992                 if (strcmp(ftrace_mod->module, mod) != 0)
3993                         continue;
3994 
3995                 if (ftrace_mod->func)
3996                         func = kstrdup(ftrace_mod->func, GFP_KERNEL);
3997                 else
3998                         func = kstrdup("*", GFP_KERNEL);
3999 
4000                 if (!func) /* warn? */
4001                         continue;
4002 
4003                 list_del(&ftrace_mod->list);
4004                 list_add(&ftrace_mod->list, &process_mods);
4005 
4006                 /* Use the newly allocated func, as it may be "*" */
4007                 kfree(ftrace_mod->func);
4008                 ftrace_mod->func = func;
4009         }
4010 
4011         mutex_unlock(&ftrace_lock);
4012 
4013         list_for_each_entry_safe(ftrace_mod, n, &process_mods, list) {
4014 
4015                 func = ftrace_mod->func;
4016 
4017                 /* Grabs ftrace_lock, which is why we have this extra step */
4018                 match_records(new_hash, func, strlen(func), mod);
4019                 free_ftrace_mod(ftrace_mod);
4020         }
4021 
4022         if (enable && list_empty(head))
4023                 new_hash->flags &= ~FTRACE_HASH_FL_MOD;
4024 
4025         mutex_lock(&ftrace_lock);
4026 
4027         ret = ftrace_hash_move_and_update_ops(ops, orig_hash,
4028                                               new_hash, enable);
4029         mutex_unlock(&ftrace_lock);
4030 
4031  out:
4032         mutex_unlock(&ops->func_hash->regex_lock);
4033 
4034         free_ftrace_hash(new_hash);
4035 }
4036 
4037 static void process_cached_mods(const char *mod_name)
4038 {
4039         struct trace_array *tr;
4040         char *mod;
4041 
4042         mod = kstrdup(mod_name, GFP_KERNEL);
4043         if (!mod)
4044                 return;
4045 
4046         mutex_lock(&trace_types_lock);
4047         list_for_each_entry(tr, &ftrace_trace_arrays, list) {
4048                 if (!list_empty(&tr->mod_trace))
4049                         process_mod_list(&tr->mod_trace, tr->ops, mod, true);
4050                 if (!list_empty(&tr->mod_notrace))
4051                         process_mod_list(&tr->mod_notrace, tr->ops, mod, false);
4052         }
4053         mutex_unlock(&trace_types_lock);
4054 
4055         kfree(mod);
4056 }
4057 #endif
4058 
4059 /*
4060  * We register the module command as a template to show others how
4061  * to register the a command as well.
4062  */
4063 
4064 static int
4065 ftrace_mod_callback(struct trace_array *tr, struct ftrace_hash *hash,
4066                     char *func_orig, char *cmd, char *module, int enable)
4067 {
4068         char *func;
4069         int ret;
4070 
4071         /* match_records() modifies func, and we need the original */
4072         func = kstrdup(func_orig, GFP_KERNEL);
4073         if (!func)
4074                 return -ENOMEM;
4075 
4076         /*
4077          * cmd == 'mod' because we only registered this func
4078          * for the 'mod' ftrace_func_command.
4079          * But if you register one func with multiple commands,
4080          * you can tell which command was used by the cmd
4081          * parameter.
4082          */
4083         ret = match_records(hash, func, strlen(func), module);
4084         kfree(func);
4085 
4086         if (!ret)
4087                 return cache_mod(tr, func_orig, module, enable);
4088         if (ret < 0)
4089                 return ret;
4090         return 0;
4091 }
4092 
4093 static struct ftrace_func_command ftrace_mod_cmd = {
4094         .name                   = "mod",
4095         .func                   = ftrace_mod_callback,
4096 };
4097 
4098 static int __init ftrace_mod_cmd_init(void)
4099 {
4100         return register_ftrace_command(&ftrace_mod_cmd);
4101 }
4102 core_initcall(ftrace_mod_cmd_init);
4103 
4104 static void function_trace_probe_call(unsigned long ip, unsigned long parent_ip,
4105                                       struct ftrace_ops *op, struct pt_regs *pt_regs)
4106 {
4107         struct ftrace_probe_ops *probe_ops;
4108         struct ftrace_func_probe *probe;
4109 
4110         probe = container_of(op, struct ftrace_func_probe, ops);
4111         probe_ops = probe->probe_ops;
4112 
4113         /*
4114          * Disable preemption for these calls to prevent a RCU grace
4115          * period. This syncs the hash iteration and freeing of items
4116          * on the hash. rcu_read_lock is too dangerous here.
4117          */
4118         preempt_disable_notrace();
4119         probe_ops->func(ip, parent_ip, probe->tr, probe_ops, probe->data);
4120         preempt_enable_notrace();
4121 }
4122 
4123 struct ftrace_func_map {
4124         struct ftrace_func_entry        entry;
4125         void                            *data;
4126 };
4127 
4128 struct ftrace_func_mapper {
4129         struct ftrace_hash              hash;
4130 };
4131 
4132 /**
4133  * allocate_ftrace_func_mapper - allocate a new ftrace_func_mapper
4134  *
4135  * Returns a ftrace_func_mapper descriptor that can be used to map ips to data.
4136  */
4137 struct ftrace_func_mapper *allocate_ftrace_func_mapper(void)
4138 {
4139         struct ftrace_hash *hash;
4140 
4141         /*
4142          * The mapper is simply a ftrace_hash, but since the entries
4143          * in the hash are not ftrace_func_entry type, we define it
4144          * as a separate structure.
4145          */
4146         hash = alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS);
4147         return (struct ftrace_func_mapper *)hash;
4148 }
4149 
4150 /**
4151  * ftrace_func_mapper_find_ip - Find some data mapped to an ip
4152  * @mapper: The mapper that has the ip maps
4153  * @ip: the instruction pointer to find the data for
4154  *
4155  * Returns the data mapped to @ip if found otherwise NULL. The return
4156  * is actually the address of the mapper data pointer. The address is
4157  * returned for use cases where the data is no bigger than a long, and
4158  * the user can use the data pointer as its data instead of having to
4159  * allocate more memory for the reference.
4160  */
4161 void **ftrace_func_mapper_find_ip(struct ftrace_func_mapper *mapper,
4162                                   unsigned long ip)
4163 {
4164         struct ftrace_func_entry *entry;
4165         struct ftrace_func_map *map;
4166 
4167         entry = ftrace_lookup_ip(&mapper->hash, ip);
4168         if (!entry)
4169                 return NULL;
4170 
4171         map = (struct ftrace_func_map *)entry;
4172         return &map->data;
4173 }
4174 
4175 /**
4176  * ftrace_func_mapper_add_ip - Map some data to an ip
4177  * @mapper: The mapper that has the ip maps
4178  * @ip: The instruction pointer address to map @data to
4179  * @data: The data to map to @ip
4180  *
4181  * Returns 0 on succes otherwise an error.
4182  */
4183 int ftrace_func_mapper_add_ip(struct ftrace_func_mapper *mapper,
4184                               unsigned long ip, void *data)
4185 {
4186         struct ftrace_func_entry *entry;
4187         struct ftrace_func_map *map;
4188 
4189         entry = ftrace_lookup_ip(&mapper->hash, ip);
4190         if (entry)
4191                 return -EBUSY;
4192 
4193         map = kmalloc(sizeof(*map), GFP_KERNEL);
4194         if (!map)
4195                 return -ENOMEM;
4196 
4197         map->entry.ip = ip;
4198         map->data = data;
4199 
4200         __add_hash_entry(&mapper->hash, &map->entry);
4201 
4202         return 0;
4203 }
4204 
4205 /**
4206  * ftrace_func_mapper_remove_ip - Remove an ip from the mapping
4207  * @mapper: The mapper that has the ip maps
4208  * @ip: The instruction pointer address to remove the data from
4209  *
4210  * Returns the data if it is found, otherwise NULL.
4211  * Note, if the data pointer is used as the data itself, (see 
4212  * ftrace_func_mapper_find_ip(), then the return value may be meaningless,
4213  * if the data pointer was set to zero.
4214  */
4215 void *ftrace_func_mapper_remove_ip(struct ftrace_func_mapper *mapper,
4216                                    unsigned long ip)
4217 {
4218         struct ftrace_func_entry *entry;
4219         struct ftrace_func_map *map;
4220         void *data;
4221 
4222         entry = ftrace_lookup_ip(&mapper->hash, ip);
4223         if (!entry)
4224                 return NULL;
4225 
4226         map = (struct ftrace_func_map *)entry;
4227         data = map->data;
4228 
4229         remove_hash_entry(&mapper->hash, entry);
4230         kfree(entry);
4231 
4232         return data;
4233 }
4234 
4235 /**
4236  * free_ftrace_func_mapper - free a mapping of ips and data
4237  * @mapper: The mapper that has the ip maps
4238  * @free_func: A function to be called on each data item.
4239  *
4240  * This is used to free the function mapper. The @free_func is optional
4241  * and can be used if the data needs to be freed as well.
4242  */
4243 void free_ftrace_func_mapper(struct ftrace_func_mapper *mapper,
4244                              ftrace_mapper_func free_func)
4245 {
4246         struct ftrace_func_entry *entry;
4247         struct ftrace_func_map *map;
4248         struct hlist_head *hhd;
4249         int size = 1 << mapper->hash.size_bits;
4250         int i;
4251 
4252         if (free_func && mapper->hash.count) {
4253                 for (i = 0; i < size; i++) {
4254                         hhd = &mapper->hash.buckets[i];
4255                         hlist_for_each_entry(entry, hhd, hlist) {
4256                                 map = (struct ftrace_func_map *)entry;
4257                                 free_func(map);
4258                         }
4259                 }
4260         }
4261         free_ftrace_hash(&mapper->hash);
4262 }
4263 
4264 static void release_probe(struct ftrace_func_probe *probe)
4265 {
4266         struct ftrace_probe_ops *probe_ops;
4267 
4268         mutex_lock(&ftrace_lock);
4269 
4270         WARN_ON(probe->ref <= 0);
4271 
4272         /* Subtract the ref that was used to protect this instance */
4273         probe->ref--;
4274 
4275         if (!probe->ref) {
4276                 probe_ops = probe->probe_ops;
4277                 /*
4278                  * Sending zero as ip tells probe_ops to free
4279                  * the probe->data itself
4280                  */
4281                 if (probe_ops->free)
4282                         probe_ops->free(probe_ops, probe->tr, 0, probe->data);
4283                 list_del(&probe->list);
4284                 kfree(probe);
4285         }
4286         mutex_unlock(&ftrace_lock);
4287 }
4288 
4289 static void acquire_probe_locked(struct ftrace_func_probe *probe)
4290 {
4291         /*
4292          * Add one ref to keep it from being freed when releasing the
4293          * ftrace_lock mutex.
4294          */
4295         probe->ref++;
4296 }
4297 
4298 int
4299 register_ftrace_function_probe(char *glob, struct trace_array *tr,
4300                                struct ftrace_probe_ops *probe_ops,
4301                                void *data)
4302 {
4303         struct ftrace_func_entry *entry;
4304         struct ftrace_func_probe *probe;
4305         struct ftrace_hash **orig_hash;
4306         struct ftrace_hash *old_hash;
4307         struct ftrace_hash *hash;
4308         int count = 0;
4309         int size;
4310         int ret;
4311         int i;
4312 
4313         if (WARN_ON(!tr))
4314                 return -EINVAL;
4315 
4316         /* We do not support '!' for function probes */
4317         if (WARN_ON(glob[0] == '!'))
4318                 return -EINVAL;
4319 
4320 
4321         mutex_lock(&ftrace_lock);
4322         /* Check if the probe_ops is already registered */
4323         list_for_each_entry(probe, &tr->func_probes, list) {
4324                 if (probe->probe_ops == probe_ops)
4325                         break;
4326         }
4327         if (&probe->list == &tr->func_probes) {
4328                 probe = kzalloc(sizeof(*probe), GFP_KERNEL);
4329                 if (!probe) {
4330                         mutex_unlock(&ftrace_lock);
4331                         return -ENOMEM;
4332                 }
4333                 probe->probe_ops = probe_ops;
4334                 probe->ops.func = function_trace_probe_call;
4335                 probe->tr = tr;
4336                 ftrace_ops_init(&probe->ops);
4337                 list_add(&probe->list, &tr->func_probes);
4338         }
4339 
4340         acquire_probe_locked(probe);
4341 
4342         mutex_unlock(&ftrace_lock);
4343 
4344         mutex_lock(&probe->ops.func_hash->regex_lock);
4345 
4346         orig_hash = &probe->ops.func_hash->filter_hash;
4347         old_hash = *orig_hash;
4348         hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, old_hash);
4349 
4350         ret = ftrace_match_records(hash, glob, strlen(glob));
4351 
4352         /* Nothing found? */
4353         if (!ret)
4354                 ret = -EINVAL;
4355 
4356         if (ret < 0)
4357                 goto out;
4358 
4359         size = 1 << hash->size_bits;
4360         for (i = 0; i < size; i++) {
4361                 hlist_for_each_entry(entry, &hash->buckets[i], hlist) {
4362                         if (ftrace_lookup_ip(old_hash, entry->ip))
4363                                 continue;
4364                         /*
4365                          * The caller might want to do something special
4366                          * for each function we find. We call the callback
4367                          * to give the caller an opportunity to do so.
4368                          */
4369                         if (probe_ops->init) {
4370                                 ret = probe_ops->init(probe_ops, tr,
4371                                                       entry->ip, data,
4372                                                       &probe->data);
4373                                 if (ret < 0) {
4374                                         if (probe_ops->free && count)
4375                                                 probe_ops->free(probe_ops, tr,
4376                                                                 0, probe->data);
4377                                         probe->data = NULL;
4378                                         goto out;
4379                                 }
4380                         }
4381                         count++;
4382                 }
4383         }
4384 
4385         mutex_lock(&ftrace_lock);
4386 
4387         if (!count) {
4388                 /* Nothing was added? */
4389                 ret = -EINVAL;
4390                 goto out_unlock;
4391         }
4392 
4393         ret = ftrace_hash_move_and_update_ops(&probe->ops, orig_hash,
4394                                               hash, 1);
4395         if (ret < 0)
4396                 goto err_unlock;
4397 
4398         /* One ref for each new function traced */
4399         probe->ref += count;
4400 
4401         if (!(probe->ops.flags & FTRACE_OPS_FL_ENABLED))
4402                 ret = ftrace_startup(&probe->ops, 0);
4403 
4404  out_unlock:
4405         mutex_unlock(&ftrace_lock);
4406 
4407         if (!ret)
4408                 ret = count;
4409  out:
4410         mutex_unlock(&probe->ops.func_hash->regex_lock);
4411         free_ftrace_hash(hash);
4412 
4413         release_probe(probe);
4414 
4415         return ret;
4416 
4417  err_unlock:
4418         if (!probe_ops->free || !count)
4419                 goto out_unlock;
4420 
4421         /* Failed to do the move, need to call the free functions */
4422         for (i = 0; i < size; i++) {
4423                 hlist_for_each_entry(entry, &hash->buckets[i], hlist) {
4424                         if (ftrace_lookup_ip(old_hash, entry->ip))
4425                                 continue;
4426                         probe_ops->free(probe_ops, tr, entry->ip, probe->data);
4427                 }
4428         }
4429         goto out_unlock;
4430 }
4431 
4432 int
4433 unregister_ftrace_function_probe_func(char *glob, struct trace_array *tr,
4434                                       struct ftrace_probe_ops *probe_ops)
4435 {
4436         struct ftrace_ops_hash old_hash_ops;
4437         struct ftrace_func_entry *entry;
4438         struct ftrace_func_probe *probe;
4439         struct ftrace_glob func_g;
4440         struct ftrace_hash **orig_hash;
4441         struct ftrace_hash *old_hash;
4442         struct ftrace_hash *hash = NULL;
4443         struct hlist_node *tmp;
4444         struct hlist_head hhd;
4445         char str[KSYM_SYMBOL_LEN];
4446         int count = 0;
4447         int i, ret = -ENODEV;
4448         int size;
4449 
4450         if (!glob || !strlen(glob) || !strcmp(glob, "*"))
4451                 func_g.search = NULL;
4452         else {
4453                 int not;
4454 
4455                 func_g.type = filter_parse_regex(glob, strlen(glob),
4456                                                  &func_g.search, &not);
4457                 func_g.len = strlen(func_g.search);
4458 
4459                 /* we do not support '!' for function probes */
4460                 if (WARN_ON(not))
4461                         return -EINVAL;
4462         }
4463 
4464         mutex_lock(&ftrace_lock);
4465         /* Check if the probe_ops is already registered */
4466         list_for_each_entry(probe, &tr->func_probes, list) {
4467                 if (probe->probe_ops == probe_ops)
4468                         break;
4469         }
4470         if (&probe->list == &tr->func_probes)
4471                 goto err_unlock_ftrace;
4472 
4473         ret = -EINVAL;
4474         if (!(probe->ops.flags & FTRACE_OPS_FL_INITIALIZED))
4475                 goto err_unlock_ftrace;
4476 
4477         acquire_probe_locked(probe);
4478 
4479         mutex_unlock(&ftrace_lock);
4480 
4481         mutex_lock(&probe->ops.func_hash->regex_lock);
4482 
4483         orig_hash = &probe->ops.func_hash->filter_hash;
4484         old_hash = *orig_hash;
4485 
4486         if (ftrace_hash_empty(old_hash))
4487                 goto out_unlock;
4488 
4489         old_hash_ops.filter_hash = old_hash;
4490         /* Probes only have filters */
4491         old_hash_ops.notrace_hash = NULL;
4492 
4493         ret = -ENOMEM;
4494         hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, old_hash);
4495         if (!hash)
4496                 goto out_unlock;
4497 
4498         INIT_HLIST_HEAD(&hhd);
4499 
4500         size = 1 << hash->size_bits;
4501         for (i = 0; i < size; i++) {
4502                 hlist_for_each_entry_safe(entry, tmp, &hash->buckets[i], hlist) {
4503 
4504                         if (func_g.search) {
4505                                 kallsyms_lookup(entry->ip, NULL, NULL,
4506                                                 NULL, str);
4507                                 if (!ftrace_match(str, &func_g))
4508                                         continue;
4509                         }
4510                         count++;
4511                         remove_hash_entry(hash, entry);
4512                         hlist_add_head(&entry->hlist, &hhd);
4513                 }
4514         }
4515 
4516         /* Nothing found? */
4517         if (!count) {
4518                 ret = -EINVAL;
4519                 goto out_unlock;
4520         }
4521 
4522         mutex_lock(&ftrace_lock);
4523 
4524         WARN_ON(probe->ref < count);
4525 
4526         probe->ref -= count;
4527 
4528         if (ftrace_hash_empty(hash))
4529                 ftrace_shutdown(&probe->ops, 0);
4530 
4531         ret = ftrace_hash_move_and_update_ops(&probe->ops, orig_hash,
4532                                               hash, 1);
4533 
4534         /* still need to update the function call sites */
4535         if (ftrace_enabled && !ftrace_hash_empty(hash))
4536                 ftrace_run_modify_code(&probe->ops, FTRACE_UPDATE_CALLS,
4537                                        &old_hash_ops);
4538         synchronize_sched();
4539 
4540         hlist_for_each_entry_safe(entry, tmp, &hhd, hlist) {
4541                 hlist_del(&entry->hlist);
4542                 if (probe_ops->free)
4543                         probe_ops->free(probe_ops, tr, entry->ip, probe->data);
4544                 kfree(entry);
4545         }
4546         mutex_unlock(&ftrace_lock);
4547 
4548  out_unlock:
4549         mutex_unlock(&probe->ops.func_hash->regex_lock);
4550         free_ftrace_hash(hash);
4551 
4552         release_probe(probe);
4553 
4554         return ret;
4555 
4556  err_unlock_ftrace:
4557         mutex_unlock(&ftrace_lock);
4558         return ret;
4559 }
4560 
4561 void clear_ftrace_function_probes(struct trace_array *tr)
4562 {
4563         struct ftrace_func_probe *probe, *n;
4564 
4565         list_for_each_entry_safe(probe, n, &tr->func_probes, list)
4566                 unregister_ftrace_function_probe_func(NULL, tr, probe->probe_ops);
4567 }
4568 
4569 static LIST_HEAD(ftrace_commands);
4570 static DEFINE_MUTEX(ftrace_cmd_mutex);
4571 
4572 /*
4573  * Currently we only register ftrace commands from __init, so mark this
4574  * __init too.
4575  */
4576 __init int register_ftrace_command(struct ftrace_func_command *cmd)
4577 {
4578         struct ftrace_func_command *p;
4579         int ret = 0;
4580 
4581         mutex_lock(&ftrace_cmd_mutex);
4582         list_for_each_entry(p, &ftrace_commands, list) {
4583                 if (strcmp(cmd->name, p->name) == 0) {
4584                         ret = -EBUSY;
4585                         goto out_unlock;
4586                 }
4587         }
4588         list_add(&cmd->list, &ftrace_commands);
4589  out_unlock:
4590         mutex_unlock(&ftrace_cmd_mutex);
4591 
4592         return ret;
4593 }
4594 
4595 /*
4596  * Currently we only unregister ftrace commands from __init, so mark
4597  * this __init too.
4598  */
4599 __init int unregister_ftrace_command(struct ftrace_func_command *cmd)
4600 {
4601         struct ftrace_func_command *p, *n;
4602         int ret = -ENODEV;
4603 
4604         mutex_lock(&ftrace_cmd_mutex);
4605         list_for_each_entry_safe(p, n, &ftrace_commands, list) {
4606                 if (strcmp(cmd->name, p->name) == 0) {
4607                         ret = 0;
4608                         list_del_init(&p->list);
4609                         goto out_unlock;
4610                 }
4611         }
4612  out_unlock:
4613         mutex_unlock(&ftrace_cmd_mutex);
4614 
4615         return ret;
4616 }
4617 
4618 static int ftrace_process_regex(struct ftrace_iterator *iter,
4619                                 char *buff, int len, int enable)
4620 {
4621         struct ftrace_hash *hash = iter->hash;
4622         struct trace_array *tr = iter->ops->private;
4623         char *func, *command, *next = buff;
4624         struct ftrace_func_command *p;
4625         int ret = -EINVAL;
4626 
4627         func = strsep(&next, ":");
4628 
4629         if (!next) {
4630                 ret = ftrace_match_records(hash, func, len);
4631                 if (!ret)
4632                         ret = -EINVAL;
4633                 if (ret < 0)
4634                         return ret;
4635                 return 0;
4636         }
4637 
4638         /* command found */
4639 
4640         command = strsep(&next, ":");
4641 
4642         mutex_lock(&ftrace_cmd_mutex);
4643         list_for_each_entry(p, &ftrace_commands, list) {
4644                 if (strcmp(p->name, command) == 0) {
4645                         ret = p->func(tr, hash, func, command, next, enable);
4646                         goto out_unlock;
4647                 }
4648         }
4649  out_unlock:
4650         mutex_unlock(&ftrace_cmd_mutex);
4651 
4652         return ret;
4653 }
4654 
4655 static ssize_t
4656 ftrace_regex_write(struct file *file, const char __user *ubuf,
4657                    size_t cnt, loff_t *ppos, int enable)
4658 {
4659         struct ftrace_iterator *iter;
4660         struct trace_parser *parser;
4661         ssize_t ret, read;
4662 
4663         if (!cnt)
4664                 return 0;
4665 
4666         if (file->f_mode & FMODE_READ) {
4667                 struct seq_file *m = file->private_data;
4668                 iter = m->private;
4669         } else
4670                 iter = file->private_data;
4671 
4672         if (unlikely(ftrace_disabled))
4673                 return -ENODEV;
4674 
4675         /* iter->hash is a local copy, so we don't need regex_lock */
4676 
4677         parser = &iter->parser;
4678         read = trace_get_user(parser, ubuf, cnt, ppos);
4679 
4680         if (read >= 0 && trace_parser_loaded(parser) &&
4681             !trace_parser_cont(parser)) {
4682                 ret = ftrace_process_regex(iter, parser->buffer,
4683                                            parser->idx, enable);
4684                 trace_parser_clear(parser);
4685                 if (ret < 0)
4686                         goto out;
4687         }
4688 
4689         ret = read;
4690  out:
4691         return ret;
4692 }
4693 
4694 ssize_t
4695 ftrace_filter_write(struct file *file, const char __user *ubuf,
4696                     size_t cnt, loff_t *ppos)
4697 {
4698         return ftrace_regex_write(file, ubuf, cnt, ppos, 1);
4699 }
4700 
4701 ssize_t
4702 ftrace_notrace_write(struct file *file, const char __user *ubuf,
4703                      size_t cnt, loff_t *ppos)
4704 {
4705         return ftrace_regex_write(file, ubuf, cnt, ppos, 0);
4706 }
4707 
4708 static int
4709 ftrace_match_addr(struct ftrace_hash *hash, unsigned long ip, int remove)
4710 {
4711         struct ftrace_func_entry *entry;
4712 
4713         if (!ftrace_location(ip))
4714                 return -EINVAL;
4715 
4716         if (remove) {
4717                 entry = ftrace_lookup_ip(hash, ip);
4718                 if (!entry)
4719                         return -ENOENT;
4720                 free_hash_entry(hash, entry);
4721                 return 0;
4722         }
4723 
4724         return add_hash_entry(hash, ip);
4725 }
4726 
4727 static int
4728 ftrace_set_hash(struct ftrace_ops *ops, unsigned char *buf, int len,
4729                 unsigned long ip, int remove, int reset, int enable)
4730 {
4731         struct ftrace_hash **orig_hash;
4732         struct ftrace_hash *hash;
4733         int ret;
4734 
4735         if (unlikely(ftrace_disabled))
4736                 return -ENODEV;
4737 
4738         mutex_lock(&ops->func_hash->regex_lock);
4739 
4740         if (enable)
4741                 orig_hash = &ops->func_hash->filter_hash;
4742         else
4743                 orig_hash = &ops->func_hash->notrace_hash;
4744 
4745         if (reset)
4746                 hash = alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS);
4747         else
4748                 hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, *orig_hash);
4749 
4750         if (!hash) {
4751                 ret = -ENOMEM;
4752                 goto out_regex_unlock;
4753         }
4754 
4755         if (buf && !ftrace_match_records(hash, buf, len)) {
4756                 ret = -EINVAL;
4757                 goto out_regex_unlock;
4758         }
4759         if (ip) {
4760                 ret = ftrace_match_addr(hash, ip, remove);
4761                 if (ret < 0)
4762                         goto out_regex_unlock;
4763         }
4764 
4765         mutex_lock(&ftrace_lock);
4766         ret = ftrace_hash_move_and_update_ops(ops, orig_hash, hash, enable);
4767         mutex_unlock(&ftrace_lock);
4768 
4769  out_regex_unlock:
4770         mutex_unlock(&ops->func_hash->regex_lock);
4771 
4772         free_ftrace_hash(hash);
4773         return ret;
4774 }
4775 
4776 static int
4777 ftrace_set_addr(struct ftrace_ops *ops, unsigned long ip, int remove,
4778                 int reset, int enable)
4779 {
4780         return ftrace_set_hash(ops, 0, 0, ip, remove, reset, enable);
4781 }
4782 
4783 /**
4784  * ftrace_set_filter_ip - set a function to filter on in ftrace by address
4785  * @ops - the ops to set the filter with
4786  * @ip - the address to add to or remove from the filter.
4787  * @remove - non zero to remove the ip from the filter
4788  * @reset - non zero to reset all filters before applying this filter.
4789  *
4790  * Filters denote which functions should be enabled when tracing is enabled
4791  * If @ip is NULL, it failes to update filter.
4792  */
4793 int ftrace_set_filter_ip(struct ftrace_ops *ops, unsigned long ip,
4794                          int remove, int reset)
4795 {
4796         ftrace_ops_init(ops);
4797         return ftrace_set_addr(ops, ip, remove, reset, 1);
4798 }
4799 EXPORT_SYMBOL_GPL(ftrace_set_filter_ip);
4800 
4801 /**
4802  * ftrace_ops_set_global_filter - setup ops to use global filters
4803  * @ops - the ops which will use the global filters
4804  *
4805  * ftrace users who need global function trace filtering should call this.
4806  * It can set the global filter only if ops were not initialized before.
4807  */
4808 void ftrace_ops_set_global_filter(struct ftrace_ops *ops)
4809 {
4810         if (ops->flags & FTRACE_OPS_FL_INITIALIZED)
4811                 return;
4812 
4813         ftrace_ops_init(ops);
4814         ops->func_hash = &global_ops.local_hash;
4815 }
4816 EXPORT_SYMBOL_GPL(ftrace_ops_set_global_filter);
4817 
4818 static int
4819 ftrace_set_regex(struct ftrace_ops *ops, unsigned char *buf, int len,
4820                  int reset, int enable)
4821 {
4822         return ftrace_set_hash(ops, buf, len, 0, 0, reset, enable);
4823 }
4824 
4825 /**
4826  * ftrace_set_filter - set a function to filter on in ftrace
4827  * @ops - the ops to set the filter with
4828  * @buf - the string that holds the function filter text.
4829  * @len - the length of the string.
4830  * @reset - non zero to reset all filters before applying this filter.
4831  *
4832  * Filters denote which functions should be enabled when tracing is enabled.
4833  * If @buf is NULL and reset is set, all functions will be enabled for tracing.
4834  */
4835 int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf,
4836                        int len, int reset)
4837 {
4838         ftrace_ops_init(ops);
4839         return ftrace_set_regex(ops, buf, len, reset, 1);
4840 }
4841 EXPORT_SYMBOL_GPL(ftrace_set_filter);
4842 
4843 /**
4844  * ftrace_set_notrace - set a function to not trace in ftrace
4845  * @ops - the ops to set the notrace filter with
4846  * @buf - the string that holds the function notrace text.
4847  * @len - the length of the string.
4848  * @reset - non zero to reset all filters before applying this filter.
4849  *
4850  * Notrace Filters denote which functions should not be enabled when tracing
4851  * is enabled. If @buf is NULL and reset is set, all functions will be enabled
4852  * for tracing.
4853  */
4854 int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf,
4855                         int len, int reset)
4856 {
4857         ftrace_ops_init(ops);
4858         return ftrace_set_regex(ops, buf, len, reset, 0);
4859 }
4860 EXPORT_SYMBOL_GPL(ftrace_set_notrace);
4861 /**
4862  * ftrace_set_global_filter - set a function to filter on with global tracers
4863  * @buf - the string that holds the function filter text.
4864  * @len - the length of the string.
4865  * @reset - non zero to reset all filters before applying this filter.
4866  *
4867  * Filters denote which functions should be enabled when tracing is enabled.
4868  * If @buf is NULL and reset is set, all functions will be enabled for tracing.
4869  */
4870 void ftrace_set_global_filter(unsigned char *buf, int len, int reset)
4871 {
4872         ftrace_set_regex(&global_ops, buf, len, reset, 1);
4873 }
4874 EXPORT_SYMBOL_GPL(ftrace_set_global_filter);
4875 
4876 /**
4877  * ftrace_set_global_notrace - set a function to not trace with global tracers
4878  * @buf - the string that holds the function notrace text.
4879  * @len - the length of the string.
4880  * @reset - non zero to reset all filters before applying this filter.
4881  *
4882  * Notrace Filters denote which functions should not be enabled when tracing
4883  * is enabled. If @buf is NULL and reset is set, all functions will be enabled
4884  * for tracing.
4885  */
4886 void ftrace_set_global_notrace(unsigned char *buf, int len, int reset)
4887 {
4888         ftrace_set_regex(&global_ops, buf, len, reset, 0);
4889 }
4890 EXPORT_SYMBOL_GPL(ftrace_set_global_notrace);
4891 
4892 /*
4893  * command line interface to allow users to set filters on boot up.
4894  */
4895 #define FTRACE_FILTER_SIZE              COMMAND_LINE_SIZE
4896 static char ftrace_notrace_buf[FTRACE_FILTER_SIZE] __initdata;
4897 static char ftrace_filter_buf[FTRACE_FILTER_SIZE] __initdata;
4898 
4899 /* Used by function selftest to not test if filter is set */
4900 bool ftrace_filter_param __initdata;
4901 
4902 static int __init set_ftrace_notrace(char *str)
4903 {
4904         ftrace_filter_param = true;
4905         strlcpy(ftrace_notrace_buf, str, FTRACE_FILTER_SIZE);
4906         return 1;
4907 }
4908 __setup("ftrace_notrace=", set_ftrace_notrace);
4909 
4910 static int __init set_ftrace_filter(char *str)
4911 {
4912         ftrace_filter_param = true;
4913         strlcpy(ftrace_filter_buf, str, FTRACE_FILTER_SIZE);
4914         return 1;
4915 }
4916 __setup("ftrace_filter=", set_ftrace_filter);
4917 
4918 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
4919 static char ftrace_graph_buf[FTRACE_FILTER_SIZE] __initdata;
4920 static char ftrace_graph_notrace_buf[FTRACE_FILTER_SIZE] __initdata;
4921 static int ftrace_graph_set_hash(struct ftrace_hash *hash, char *buffer);
4922 
4923 static int __init set_graph_function(char *str)
4924 {
4925         strlcpy(ftrace_graph_buf, str, FTRACE_FILTER_SIZE);
4926         return 1;
4927 }
4928 __setup("ftrace_graph_filter=", set_graph_function);
4929 
4930 static int __init set_graph_notrace_function(char *str)
4931 {
4932         strlcpy(ftrace_graph_notrace_buf, str, FTRACE_FILTER_SIZE);
4933         return 1;
4934 }
4935 __setup("ftrace_graph_notrace=", set_graph_notrace_function);
4936 
4937 static int __init set_graph_max_depth_function(char *str)
4938 {
4939         if (!str)
4940                 return 0;
4941         fgraph_max_depth = simple_strtoul(str, NULL, 0);
4942         return 1;
4943 }
4944 __setup("ftrace_graph_max_depth=", set_graph_max_depth_function);
4945 
4946 static void __init set_ftrace_early_graph(char *buf, int enable)
4947 {
4948         int ret;
4949         char *func;
4950         struct ftrace_hash *hash;
4951 
4952         hash = alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS);
4953         if (WARN_ON(!hash))
4954                 return;
4955 
4956         while (buf) {
4957                 func = strsep(&buf, ",");
4958                 /* we allow only one expression at a time */
4959                 ret = ftrace_graph_set_hash(hash, func);
4960                 if (ret)
4961                         printk(KERN_DEBUG "ftrace: function %s not "
4962                                           "traceable\n", func);
4963         }
4964 
4965         if (enable)
4966                 ftrace_graph_hash = hash;
4967         else
4968                 ftrace_graph_notrace_hash = hash;
4969 }
4970 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
4971 
4972 void __init
4973 ftrace_set_early_filter(struct ftrace_ops *ops, char *buf, int enable)
4974 {
4975         char *func;
4976 
4977         ftrace_ops_init(ops);
4978 
4979         while (buf) {
4980                 func = strsep(&buf, ",");
4981                 ftrace_set_regex(ops, func, strlen(func), 0, enable);
4982         }
4983 }
4984 
4985 static void __init set_ftrace_early_filters(void)
4986 {
4987         if (ftrace_filter_buf[0])
4988                 ftrace_set_early_filter(&global_ops, ftrace_filter_buf, 1);
4989         if (ftrace_notrace_buf[0])
4990                 ftrace_set_early_filter(&global_ops, ftrace_notrace_buf, 0);
4991 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
4992         if (ftrace_graph_buf[0])
4993                 set_ftrace_early_graph(ftrace_graph_buf, 1);
4994         if (ftrace_graph_notrace_buf[0])
4995                 set_ftrace_early_graph(ftrace_graph_notrace_buf, 0);
4996 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
4997 }
4998 
4999 int ftrace_regex_release(struct inode *inode, struct file *file)
5000 {
5001         struct seq_file *m = (struct seq_file *)file->private_data;
5002         struct ftrace_iterator *iter;
5003         struct ftrace_hash **orig_hash;
5004         struct trace_parser *parser;
5005         int filter_hash;
5006         int ret;
5007 
5008         if (file->f_mode & FMODE_READ) {
5009                 iter = m->private;
5010                 seq_release(inode, file);
5011         } else
5012                 iter = file->private_data;
5013 
5014         parser = &iter->parser;
5015         if (trace_parser_loaded(parser)) {
5016                 ftrace_match_records(iter->hash, parser->buffer, parser->idx);
5017         }
5018 
5019         trace_parser_put(parser);
5020 
5021         mutex_lock(&iter->ops->func_hash->regex_lock);
5022 
5023         if (file->f_mode & FMODE_WRITE) {
5024                 filter_hash = !!(iter->flags & FTRACE_ITER_FILTER);
5025 
5026                 if (filter_hash) {
5027                         orig_hash = &iter->ops->func_hash->filter_hash;
5028                         if (iter->tr && !list_empty(&iter->tr->mod_trace))
5029                                 iter->hash->flags |= FTRACE_HASH_FL_MOD;
5030                 } else
5031                         orig_hash = &iter->ops->func_hash->notrace_hash;
5032 
5033                 mutex_lock(&ftrace_lock);
5034                 ret = ftrace_hash_move_and_update_ops(iter->ops, orig_hash,
5035                                                       iter->hash, filter_hash);
5036                 mutex_unlock(&ftrace_lock);
5037         } else {
5038                 /* For read only, the hash is the ops hash */
5039                 iter->hash = NULL;
5040         }
5041 
5042         mutex_unlock(&iter->ops->func_hash->regex_lock);
5043         free_ftrace_hash(iter->hash);
5044         kfree(iter);
5045 
5046         return 0;
5047 }
5048 
5049 static const struct file_operations ftrace_avail_fops = {
5050         .open = ftrace_avail_open,
5051         .read = seq_read,
5052         .llseek = seq_lseek,
5053         .release = seq_release_private,
5054 };
5055 
5056 static const struct file_operations ftrace_enabled_fops = {
5057         .open = ftrace_enabled_open,
5058         .read = seq_read,
5059         .llseek = seq_lseek,
5060         .release = seq_release_private,
5061 };
5062 
5063 static const struct file_operations ftrace_filter_fops = {
5064         .open = ftrace_filter_open,
5065         .read = seq_read,
5066         .write = ftrace_filter_write,
5067         .llseek = tracing_lseek,
5068         .release = ftrace_regex_release,
5069 };
5070 
5071 static const struct file_operations ftrace_notrace_fops = {
5072         .open = ftrace_notrace_open,
5073         .read = seq_read,
5074         .write = ftrace_notrace_write,
5075         .llseek = tracing_lseek,
5076         .release = ftrace_regex_release,
5077 };
5078 
5079 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
5080 
5081 static DEFINE_MUTEX(graph_lock);
5082 
5083 struct ftrace_hash *ftrace_graph_hash = EMPTY_HASH;
5084 struct ftrace_hash *ftrace_graph_notrace_hash = EMPTY_HASH;
5085 
5086 enum graph_filter_type {
5087         GRAPH_FILTER_NOTRACE    = 0,
5088         GRAPH_FILTER_FUNCTION,
5089 };
5090 
5091 #define FTRACE_GRAPH_EMPTY      ((void *)1)
5092 
5093 struct ftrace_graph_data {
5094         struct ftrace_hash              *hash;
5095         struct ftrace_func_entry        *entry;
5096         int                             idx;   /* for hash table iteration */
5097         enum graph_filter_type          type;
5098         struct ftrace_hash              *new_hash;
5099         const struct seq_operations     *seq_ops;
5100         struct trace_parser             parser;
5101 };
5102 
5103 static void *
5104 __g_next(struct seq_file *m, loff_t *pos)
5105 {
5106         struct ftrace_graph_data *fgd = m->private;
5107         struct ftrace_func_entry *entry = fgd->entry;
5108         struct hlist_head *head;
5109         int i, idx = fgd->idx;
5110 
5111         if (*pos >= fgd->hash->count)
5112                 return NULL;
5113 
5114         if (entry) {
5115                 hlist_for_each_entry_continue(entry, hlist) {
5116                         fgd->entry = entry;
5117                         return entry;
5118                 }
5119 
5120                 idx++;
5121         }
5122 
5123         for (i = idx; i < 1 << fgd->hash->size_bits; i++) {
5124                 head = &fgd->hash->buckets[i];
5125                 hlist_for_each_entry(entry, head, hlist) {
5126                         fgd->entry = entry;
5127                         fgd->idx = i;
5128                         return entry;
5129                 }
5130         }
5131         return NULL;
5132 }
5133 
5134 static void *
5135 g_next(struct seq_file *m, void *v, loff_t *pos)
5136 {
5137         (*pos)++;
5138         return __g_next(m, pos);
5139 }
5140 
5141 static void *g_start(struct seq_file *m, loff_t *pos)
5142 {
5143         struct ftrace_graph_data *fgd = m->private;
5144 
5145         mutex_lock(&graph_lock);
5146 
5147         if (fgd->type == GRAPH_FILTER_FUNCTION)
5148                 fgd->hash = rcu_dereference_protected(ftrace_graph_hash,
5149                                         lockdep_is_held(&graph_lock));
5150         else
5151                 fgd->hash = rcu_dereference_protected(ftrace_graph_notrace_hash,
5152                                         lockdep_is_held(&graph_lock));
5153 
5154         /* Nothing, tell g_show to print all functions are enabled */
5155         if (ftrace_hash_empty(fgd->hash) && !*pos)
5156                 return FTRACE_GRAPH_EMPTY;
5157 
5158         fgd->idx = 0;
5159         fgd->entry = NULL;
5160         return __g_next(m, pos);
5161 }
5162 
5163 static void g_stop(struct seq_file *m, void *p)
5164 {
5165         mutex_unlock(&graph_lock);
5166 }
5167 
5168 static int g_show(struct seq_file *m, void *v)
5169 {
5170         struct ftrace_func_entry *entry = v;
5171 
5172         if (!entry)
5173                 return 0;
5174 
5175         if (entry == FTRACE_GRAPH_EMPTY) {
5176                 struct ftrace_graph_data *fgd = m->private;
5177 
5178                 if (fgd->type == GRAPH_FILTER_FUNCTION)
5179                         seq_puts(m, "#### all functions enabled ####\n");
5180                 else
5181                         seq_puts(m, "#### no functions disabled ####\n");
5182                 return 0;
5183         }
5184 
5185         seq_printf(m, "%ps\n", (void *)entry->ip);
5186 
5187         return 0;
5188 }
5189 
5190 static const struct seq_operations ftrace_graph_seq_ops = {
5191         .start = g_start,
5192         .next = g_next,
5193         .stop = g_stop,
5194         .show = g_show,
5195 };
5196 
5197 static int
5198 __ftrace_graph_open(struct inode *inode, struct file *file,
5199                     struct ftrace_graph_data *fgd)
5200 {
5201         int ret = 0;
5202         struct ftrace_hash *new_hash = NULL;
5203 
5204         if (file->f_mode & FMODE_WRITE) {
5205                 const int size_bits = FTRACE_HASH_DEFAULT_BITS;
5206 
5207                 if (trace_parser_get_init(&fgd->parser, FTRACE_BUFF_MAX))
5208                         return -ENOMEM;
5209 
5210                 if (file->f_flags & O_TRUNC)
5211                         new_hash = alloc_ftrace_hash(size_bits);
5212                 else
5213                         new_hash = alloc_and_copy_ftrace_hash(size_bits,
5214                                                               fgd->hash);
5215                 if (!new_hash) {
5216                         ret = -ENOMEM;
5217                         goto out;
5218                 }
5219         }
5220 
5221         if (file->f_mode & FMODE_READ) {
5222                 ret = seq_open(file, &ftrace_graph_seq_ops);
5223                 if (!ret) {
5224                         struct seq_file *m = file->private_data;
5225                         m->private = fgd;
5226                 } else {
5227                         /* Failed */
5228                         free_ftrace_hash(new_hash);
5229                         new_hash = NULL;
5230                 }
5231         } else
5232                 file->private_data = fgd;
5233 
5234 out:
5235         if (ret < 0 && file->f_mode & FMODE_WRITE)
5236                 trace_parser_put(&fgd->parser);
5237 
5238         fgd->new_hash = new_hash;
5239 
5240         /*
5241          * All uses of fgd->hash must be taken with the graph_lock
5242          * held. The graph_lock is going to be released, so force
5243          * fgd->hash to be reinitialized when it is taken again.
5244          */
5245         fgd->hash = NULL;
5246 
5247         return ret;
5248 }
5249 
5250 static int
5251 ftrace_graph_open(struct inode *inode, struct file *file)
5252 {
5253         struct ftrace_graph_data *fgd;
5254         int ret;
5255 
5256         if (unlikely(ftrace_disabled))
5257                 return -ENODEV;
5258 
5259         fgd = kmalloc(sizeof(*fgd), GFP_KERNEL);
5260         if (fgd == NULL)
5261                 return -ENOMEM;
5262 
5263         mutex_lock(&graph_lock);
5264 
5265         fgd->hash = rcu_dereference_protected(ftrace_graph_hash,
5266                                         lockdep_is_held(&graph_lock));
5267         fgd->type = GRAPH_FILTER_FUNCTION;
5268         fgd->seq_ops = &ftrace_graph_seq_ops;
5269 
5270         ret = __ftrace_graph_open(inode, file, fgd);
5271         if (ret < 0)
5272                 kfree(fgd);
5273 
5274         mutex_unlock(&graph_lock);
5275         return ret;
5276 }
5277 
5278 static int
5279 ftrace_graph_notrace_open(struct inode *inode, struct file *file)
5280 {
5281         struct ftrace_graph_data *fgd;
5282         int ret;
5283 
5284         if (unlikely(ftrace_disabled))
5285                 return -ENODEV;
5286 
5287         fgd = kmalloc(sizeof(*fgd), GFP_KERNEL);
5288         if (fgd == NULL)
5289                 return -ENOMEM;
5290 
5291         mutex_lock(&graph_lock);
5292 
5293         fgd->hash = rcu_dereference_protected(ftrace_graph_notrace_hash,
5294                                         lockdep_is_held(&graph_lock));
5295         fgd->type = GRAPH_FILTER_NOTRACE;
5296         fgd->seq_ops = &ftrace_graph_seq_ops;
5297 
5298         ret = __ftrace_graph_open(inode, file, fgd);
5299         if (ret < 0)
5300                 kfree(fgd);
5301 
5302         mutex_unlock(&graph_lock);
5303         return ret;
5304 }
5305 
5306 static int
5307 ftrace_graph_release(struct inode *inode, struct file *file)
5308 {
5309         struct ftrace_graph_data *fgd;
5310         struct ftrace_hash *old_hash, *new_hash;
5311         struct trace_parser *parser;
5312         int ret = 0;
5313 
5314         if (file->f_mode & FMODE_READ) {
5315                 struct seq_file *m = file->private_data;
5316 
5317                 fgd = m->private;
5318                 seq_release(inode, file);
5319         } else {
5320                 fgd = file->private_data;
5321         }
5322 
5323 
5324         if (file->f_mode & FMODE_WRITE) {
5325 
5326                 parser = &fgd->parser;
5327 
5328                 if (trace_parser_loaded((parser))) {
5329                         ret = ftrace_graph_set_hash(fgd->new_hash,
5330                                                     parser->buffer);
5331                 }
5332 
5333                 trace_parser_put(parser);
5334 
5335                 new_hash = __ftrace_hash_move(fgd->new_hash);
5336                 if (!new_hash) {
5337                         ret = -ENOMEM;
5338                         goto out;
5339                 }
5340 
5341                 mutex_lock(&graph_lock);
5342 
5343                 if (fgd->type == GRAPH_FILTER_FUNCTION) {
5344                         old_hash = rcu_dereference_protected(ftrace_graph_hash,
5345                                         lockdep_is_held(&graph_lock));
5346                         rcu_assign_pointer(ftrace_graph_hash, new_hash);
5347                 } else {
5348                         old_hash = rcu_dereference_protected(ftrace_graph_notrace_hash,
5349                                         lockdep_is_held(&graph_lock));
5350                         rcu_assign_pointer(ftrace_graph_notrace_hash, new_hash);
5351                 }
5352 
5353                 mutex_unlock(&graph_lock);
5354 
5355                 /* Wait till all users are no longer using the old hash */
5356                 synchronize_sched();
5357 
5358                 free_ftrace_hash(old_hash);
5359         }
5360 
5361  out:
5362         free_ftrace_hash(fgd->new_hash);
5363         kfree(fgd);
5364 
5365         return ret;
5366 }
5367 
5368 static int
5369 ftrace_graph_set_hash(struct ftrace_hash *hash, char *buffer)
5370 {
5371         struct ftrace_glob func_g;
5372         struct dyn_ftrace *rec;
5373         struct ftrace_page *pg;
5374         struct ftrace_func_entry *entry;
5375         int fail = 1;
5376         int not;
5377 
5378         /* decode regex */
5379         func_g.type = filter_parse_regex(buffer, strlen(buffer),
5380                                          &func_g.search, &not);
5381 
5382         func_g.len = strlen(func_g.search);
5383 
5384         mutex_lock(&ftrace_lock);
5385 
5386         if (unlikely(ftrace_disabled)) {
5387                 mutex_unlock(&ftrace_lock);
5388                 return -ENODEV;
5389         }
5390 
5391         do_for_each_ftrace_rec(pg, rec) {
5392 
5393                 if (rec->flags & FTRACE_FL_DISABLED)
5394                         continue;
5395 
5396                 if (ftrace_match_record(rec, &func_g, NULL, 0)) {
5397                         entry = ftrace_lookup_ip(hash, rec->ip);
5398 
5399                         if (!not) {
5400                                 fail = 0;
5401 
5402                                 if (entry)
5403                                         continue;
5404                                 if (add_hash_entry(hash, rec->ip) < 0)
5405                                         goto out;
5406                         } else {
5407                                 if (entry) {
5408                                         free_hash_entry(hash, entry);
5409                                         fail = 0;
5410                                 }
5411                         }
5412                 }
5413         } while_for_each_ftrace_rec();
5414 out:
5415         mutex_unlock(&ftrace_lock);
5416 
5417         if (fail)
5418                 return -EINVAL;
5419 
5420         return 0;
5421 }
5422 
5423 static ssize_t
5424 ftrace_graph_write(struct file *file, const char __user *ubuf,
5425                    size_t cnt, loff_t *ppos)
5426 {
5427         ssize_t read, ret = 0;
5428         struct ftrace_graph_data *fgd = file->private_data;
5429         struct trace_parser *parser;
5430 
5431         if (!cnt)
5432                 return 0;
5433 
5434         /* Read mode uses seq functions */
5435         if (file->f_mode & FMODE_READ) {
5436                 struct seq_file *m = file->private_data;
5437                 fgd = m->private;
5438         }
5439 
5440         parser = &fgd->parser;
5441 
5442         read = trace_get_user(parser, ubuf, cnt, ppos);
5443 
5444         if (read >= 0 && trace_parser_loaded(parser) &&
5445             !trace_parser_cont(parser)) {
5446 
5447                 ret = ftrace_graph_set_hash(fgd->new_hash,
5448                                             parser->buffer);
5449                 trace_parser_clear(parser);
5450         }
5451 
5452         if (!ret)
5453                 ret = read;
5454 
5455         return ret;
5456 }
5457 
5458 static const struct file_operations ftrace_graph_fops = {
5459         .open           = ftrace_graph_open,
5460         .read           = seq_read,
5461         .write          = ftrace_graph_write,
5462         .llseek         = tracing_lseek,
5463         .release        = ftrace_graph_release,
5464 };
5465 
5466 static const struct file_operations ftrace_graph_notrace_fops = {
5467         .open           = ftrace_graph_notrace_open,
5468         .read           = seq_read,
5469         .write          = ftrace_graph_write,
5470         .llseek         = tracing_lseek,
5471         .release        = ftrace_graph_release,
5472 };
5473 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
5474 
5475 void ftrace_create_filter_files(struct ftrace_ops *ops,
5476                                 struct dentry *parent)
5477 {
5478 
5479         trace_create_file("set_ftrace_filter", 0644, parent,
5480                           ops, &ftrace_filter_fops);
5481 
5482         trace_create_file("set_ftrace_notrace", 0644, parent,
5483                           ops, &ftrace_notrace_fops);
5484 }
5485 
5486 /*
5487  * The name "destroy_filter_files" is really a misnomer. Although
5488  * in the future, it may actualy delete the files, but this is
5489  * really intended to make sure the ops passed in are disabled
5490  * and that when this function returns, the caller is free to
5491  * free the ops.
5492  *
5493  * The "destroy" name is only to match the "create" name that this
5494  * should be paired with.
5495  */
5496 void ftrace_destroy_filter_files(struct ftrace_ops *ops)
5497 {
5498         mutex_lock(&ftrace_lock);
5499         if (ops->flags & FTRACE_OPS_FL_ENABLED)
5500                 ftrace_shutdown(ops, 0);
5501         ops->flags |= FTRACE_OPS_FL_DELETED;
5502         mutex_unlock(&ftrace_lock);
5503 }
5504 
5505 static __init int ftrace_init_dyn_tracefs(struct dentry *d_tracer)
5506 {
5507 
5508         trace_create_file("available_filter_functions", 0444,
5509                         d_tracer, NULL, &ftrace_avail_fops);
5510 
5511         trace_create_file("enabled_functions", 0444,
5512                         d_tracer, NULL, &ftrace_enabled_fops);
5513 
5514         ftrace_create_filter_files(&global_ops, d_tracer);
5515 
5516 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
5517         trace_create_file("set_graph_function", 0644, d_tracer,
5518                                     NULL,
5519                                     &ftrace_graph_fops);
5520         trace_create_file("set_graph_notrace", 0644, d_tracer,
5521                                     NULL,
5522                                     &ftrace_graph_notrace_fops);
5523 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
5524 
5525         return 0;
5526 }
5527 
5528 static int ftrace_cmp_ips(const void *a, const void *b)
5529 {
5530         const unsigned long *ipa = a;
5531         const unsigned long *ipb = b;
5532 
5533         if (*ipa > *ipb)
5534                 return 1;
5535         if (*ipa < *ipb)
5536                 return -1;
5537         return 0;
5538 }
5539 
5540 static int ftrace_process_locs(struct module *mod,
5541                                unsigned long *start,
5542                                unsigned long *end)
5543 {
5544         struct ftrace_page *start_pg;
5545         struct ftrace_page *pg;
5546         struct dyn_ftrace *rec;
5547         unsigned long count;
5548         unsigned long *p;
5549         unsigned long addr;
5550         unsigned long flags = 0; /* Shut up gcc */
5551         int ret = -ENOMEM;
5552 
5553         count = end - start;
5554 
5555         if (!count)
5556                 return 0;
5557 
5558         sort(start, count, sizeof(*start),
5559              ftrace_cmp_ips, NULL);
5560 
5561         start_pg = ftrace_allocate_pages(count);
5562         if (!start_pg)
5563                 return -ENOMEM;
5564 
5565         mutex_lock(&ftrace_lock);
5566 
5567         /*
5568          * Core and each module needs their own pages, as
5569          * modules will free them when they are removed.
5570          * Force a new page to be allocated for modules.
5571          */
5572         if (!mod) {
5573                 WARN_ON(ftrace_pages || ftrace_pages_start);
5574                 /* First initialization */
5575                 ftrace_pages = ftrace_pages_start = start_pg;
5576         } else {
5577                 if (!ftrace_pages)
5578                         goto out;
5579 
5580                 if (WARN_ON(ftrace_pages->next)) {
5581                         /* Hmm, we have free pages? */
5582                         while (ftrace_pages->next)
5583                                 ftrace_pages = ftrace_pages->next;
5584                 }
5585 
5586                 ftrace_pages->next = start_pg;
5587         }
5588 
5589         p = start;
5590         pg = start_pg;
5591         while (p < end) {
5592                 addr = ftrace_call_adjust(*p++);
5593                 /*
5594                  * Some architecture linkers will pad between
5595                  * the different mcount_loc sections of different
5596                  * object files to satisfy alignments.
5597                  * Skip any NULL pointers.
5598                  */
5599                 if (!addr)
5600                         continue;
5601 
5602                 if (pg->index == pg->size) {
5603                         /* We should have allocated enough */
5604                         if (WARN_ON(!pg->next))
5605                                 break;
5606                         pg = pg->next;
5607                 }
5608 
5609                 rec = &pg->records[pg->index++];
5610                 rec->ip = addr;
5611         }
5612 
5613         /* We should have used all pages */
5614         WARN_ON(pg->next);
5615 
5616         /* Assign the last page to ftrace_pages */
5617         ftrace_pages = pg;
5618 
5619         /*
5620          * We only need to disable interrupts on start up
5621          * because we are modifying code that an interrupt
5622          * may execute, and the modification is not atomic.
5623          * But for modules, nothing runs the code we modify
5624          * until we are finished with it, and there's no
5625          * reason to cause large interrupt latencies while we do it.
5626          */
5627         if (!mod)
5628                 local_irq_save(flags);
5629         ftrace_update_code(mod, start_pg);
5630         if (!mod)
5631                 local_irq_restore(flags);
5632         ret = 0;
5633  out:
5634         mutex_unlock(&ftrace_lock);
5635 
5636         return ret;
5637 }
5638 
5639 struct ftrace_mod_func {
5640         struct list_head        list;
5641         char                    *name;
5642         unsigned long           ip;
5643         unsigned int            size;
5644 };
5645 
5646 struct ftrace_mod_map {
5647         struct rcu_head         rcu;
5648         struct list_head        list;
5649         struct module           *mod;
5650         unsigned long           start_addr;
5651         unsigned long           end_addr;
5652         struct list_head        funcs;
5653         unsigned int            num_funcs;
5654 };
5655 
5656 #ifdef CONFIG_MODULES
5657 
5658 #define next_to_ftrace_page(p) container_of(p, struct ftrace_page, next)
5659 
5660 static LIST_HEAD(ftrace_mod_maps);
5661 
5662 static int referenced_filters(struct dyn_ftrace *rec)
5663 {
5664         struct ftrace_ops *ops;
5665         int cnt = 0;
5666 
5667         for (ops = ftrace_ops_list; ops != &ftrace_list_end; ops = ops->next) {
5668                 if (ops_references_rec(ops, rec))
5669                     cnt++;
5670         }
5671 
5672         return cnt;
5673 }
5674 
5675 static void
5676 clear_mod_from_hash(struct ftrace_page *pg, struct ftrace_hash *hash)
5677 {
5678         struct ftrace_func_entry *entry;
5679         struct dyn_ftrace *rec;
5680         int i;
5681 
5682         if (ftrace_hash_empty(hash))
5683                 return;
5684 
5685         for (i = 0; i < pg->index; i++) {
5686                 rec = &pg->records[i];
5687                 entry = __ftrace_lookup_ip(hash, rec->ip);
5688                 /*
5689                  * Do not allow this rec to match again.
5690                  * Yeah, it may waste some memory, but will be removed
5691                  * if/when the hash is modified again.
5692                  */
5693                 if (entry)
5694                         entry->ip = 0;
5695         }
5696 }
5697 
5698 /* Clear any records from hashs */
5699 static void clear_mod_from_hashes(struct ftrace_page *pg)
5700 {
5701         struct trace_array *tr;
5702 
5703         mutex_lock(&trace_types_lock);
5704         list_for_each_entry(tr, &ftrace_trace_arrays, list) {
5705                 if (!tr->ops || !tr->ops->func_hash)
5706                         continue;
5707                 mutex_lock(&tr->ops->func_hash->regex_lock);
5708                 clear_mod_from_hash(pg, tr->ops->func_hash->filter_hash);
5709                 clear_mod_from_hash(pg, tr->ops->func_hash->notrace_hash);
5710                 mutex_unlock(&tr->ops->func_hash->regex_lock);
5711         }
5712         mutex_unlock(&trace_types_lock);
5713 }
5714 
5715 static void ftrace_free_mod_map(struct rcu_head *rcu)
5716 {
5717         struct ftrace_mod_map *mod_map = container_of(rcu, struct ftrace_mod_map, rcu);
5718         struct ftrace_mod_func *mod_func;
5719         struct ftrace_mod_func *n;
5720 
5721         /* All the contents of mod_map are now not visible to readers */
5722         list_for_each_entry_safe(mod_func, n, &mod_map->funcs, list) {
5723                 kfree(mod_func->name);
5724                 list_del(&mod_func->list);
5725                 kfree(mod_func);
5726         }
5727 
5728         kfree(mod_map);
5729 }
5730 
5731 void ftrace_release_mod(struct module *mod)
5732 {
5733         struct ftrace_mod_map *mod_map;
5734         struct ftrace_mod_map *n;
5735         struct dyn_ftrace *rec;
5736         struct ftrace_page **last_pg;
5737         struct ftrace_page *tmp_page = NULL;
5738         struct ftrace_page *pg;
5739         int order;
5740 
5741         mutex_lock(&ftrace_lock);
5742 
5743         if (ftrace_disabled)
5744                 goto out_unlock;
5745 
5746         list_for_each_entry_safe(mod_map, n, &ftrace_mod_maps, list) {
5747                 if (mod_map->mod == mod) {
5748                         list_del_rcu(&mod_map->list);
5749                         call_rcu_sched(&mod_map->rcu, ftrace_free_mod_map);
5750                         break;
5751                 }
5752         }
5753 
5754         /*
5755          * Each module has its own ftrace_pages, remove
5756          * them from the list.
5757          */
5758         last_pg = &ftrace_pages_start;
5759         for (pg = ftrace_pages_start; pg; pg = *last_pg) {
5760                 rec = &pg->records[0];
5761                 if (within_module_core(rec->ip, mod) ||
5762                     within_module_init(rec->ip, mod)) {
5763                         /*
5764                          * As core pages are first, the first
5765                          * page should never be a module page.
5766                          */
5767                         if (WARN_ON(pg == ftrace_pages_start))
5768                                 goto out_unlock;
5769 
5770                         /* Check if we are deleting the last page */
5771                         if (pg == ftrace_pages)
5772                                 ftrace_pages = next_to_ftrace_page(last_pg);
5773 
5774                         ftrace_update_tot_cnt -= pg->index;
5775                         *last_pg = pg->next;
5776 
5777                         pg->next = tmp_page;
5778                         tmp_page = pg;
5779                 } else
5780                         last_pg = &pg->next;
5781         }
5782  out_unlock:
5783         mutex_unlock(&ftrace_lock);
5784 
5785         for (pg = tmp_page; pg; pg = tmp_page) {
5786 
5787                 /* Needs to be called outside of ftrace_lock */
5788                 clear_mod_from_hashes(pg);
5789 
5790                 order = get_count_order(pg->size / ENTRIES_PER_PAGE);
5791                 free_pages((unsigned long)pg->records, order);
5792                 tmp_page = pg->next;
5793                 kfree(pg);
5794         }
5795 }
5796 
5797 void ftrace_module_enable(struct module *mod)
5798 {
5799         struct dyn_ftrace *rec;
5800         struct ftrace_page *pg;
5801 
5802         mutex_lock(&ftrace_lock);
5803 
5804         if (ftrace_disabled)
5805                 goto out_unlock;
5806 
5807         /*
5808          * If the tracing is enabled, go ahead and enable the record.
5809          *
5810          * The reason not to enable the record immediatelly is the
5811          * inherent check of ftrace_make_nop/ftrace_make_call for
5812          * correct previous instructions.  Making first the NOP
5813          * conversion puts the module to the correct state, thus
5814          * passing the ftrace_make_call check.
5815          *
5816          * We also delay this to after the module code already set the
5817          * text to read-only, as we now need to set it back to read-write
5818          * so that we can modify the text.
5819          */
5820         if (ftrace_start_up)
5821                 ftrace_arch_code_modify_prepare();
5822 
5823         do_for_each_ftrace_rec(pg, rec) {
5824                 int cnt;
5825                 /*
5826                  * do_for_each_ftrace_rec() is a double loop.
5827                  * module text shares the pg. If a record is
5828                  * not part of this module, then skip this pg,
5829                  * which the "break" will do.
5830                  */
5831                 if (!within_module_core(rec->ip, mod) &&
5832                     !within_module_init(rec->ip, mod))
5833                         break;
5834 
5835                 cnt = 0;
5836 
5837                 /*
5838                  * When adding a module, we need to check if tracers are
5839                  * currently enabled and if they are, and can trace this record,
5840                  * we need to enable the module functions as well as update the
5841                  * reference counts for those function records.
5842                  */
5843                 if (ftrace_start_up)
5844                         cnt += referenced_filters(rec);
5845 
5846                 /* This clears FTRACE_FL_DISABLED */
5847                 rec->flags = cnt;
5848 
5849                 if (ftrace_start_up && cnt) {
5850                         int failed = __ftrace_replace_code(rec, 1);
5851                         if (failed) {
5852                                 ftrace_bug(failed, rec);
5853                                 goto out_loop;
5854                         }
5855                 }
5856 
5857         } while_for_each_ftrace_rec();
5858 
5859  out_loop:
5860         if (ftrace_start_up)
5861                 ftrace_arch_code_modify_post_process();
5862 
5863  out_unlock:
5864         mutex_unlock(&ftrace_lock);
5865 
5866         process_cached_mods(mod->name);
5867 }
5868 
5869 void ftrace_module_init(struct module *mod)
5870 {
5871         if (ftrace_disabled || !mod->num_ftrace_callsites)
5872                 return;
5873 
5874         ftrace_process_locs(mod, mod->ftrace_callsites,
5875                             mod->ftrace_callsites + mod->num_ftrace_callsites);
5876 }
5877 
5878 static void save_ftrace_mod_rec(struct ftrace_mod_map *mod_map,
5879                                 struct dyn_ftrace *rec)
5880 {
5881         struct ftrace_mod_func *mod_func;
5882         unsigned long symsize;
5883         unsigned long offset;
5884         char str[KSYM_SYMBOL_LEN];
5885         char *modname;
5886         const char *ret;
5887 
5888         ret = kallsyms_lookup(rec->ip, &symsize, &offset, &modname, str);
5889         if (!ret)
5890                 return;
5891 
5892         mod_func = kmalloc(sizeof(*mod_func), GFP_KERNEL);
5893         if (!mod_func)
5894                 return;
5895 
5896         mod_func->name = kstrdup(str, GFP_KERNEL);
5897         if (!mod_func->name) {
5898                 kfree(mod_func);
5899                 return;
5900         }
5901 
5902         mod_func->ip = rec->ip - offset;
5903         mod_func->size = symsize;
5904 
5905         mod_map->num_funcs++;
5906 
5907         list_add_rcu(&mod_func->list, &mod_map->funcs);
5908 }
5909 
5910 static struct ftrace_mod_map *
5911 allocate_ftrace_mod_map(struct module *mod,
5912                         unsigned long start, unsigned long end)
5913 {
5914         struct ftrace_mod_map *mod_map;
5915 
5916         mod_map = kmalloc(sizeof(*mod_map), GFP_KERNEL);
5917         if (!mod_map)
5918                 return NULL;
5919 
5920         mod_map->mod = mod;
5921         mod_map->start_addr = start;
5922         mod_map->end_addr = end;
5923         mod_map->num_funcs = 0;
5924 
5925         INIT_LIST_HEAD_RCU(&mod_map->funcs);
5926 
5927         list_add_rcu(&mod_map->list, &ftrace_mod_maps);
5928 
5929         return mod_map;
5930 }
5931 
5932 static const char *
5933 ftrace_func_address_lookup(struct ftrace_mod_map *mod_map,
5934                            unsigned long addr, unsigned long *size,
5935                            unsigned long *off, char *sym)
5936 {
5937         struct ftrace_mod_func *found_func =  NULL;
5938         struct ftrace_mod_func *mod_func;
5939 
5940         list_for_each_entry_rcu(mod_func, &mod_map->funcs, list) {
5941                 if (addr >= mod_func->ip &&
5942                     addr < mod_func->ip + mod_func->size) {
5943                         found_func = mod_func;
5944                         break;
5945                 }
5946         }
5947 
5948         if (found_func) {
5949                 if (size)
5950                         *size = found_func->size;
5951                 if (off)
5952                         *off = addr - found_func->ip;
5953                 if (sym)
5954                         strlcpy(sym, found_func->name, KSYM_NAME_LEN);
5955 
5956                 return found_func->name;
5957         }
5958 
5959         return NULL;
5960 }
5961 
5962 const char *
5963 ftrace_mod_address_lookup(unsigned long addr, unsigned long *size,
5964                    unsigned long *off, char **modname, char *sym)
5965 {
5966         struct ftrace_mod_map *mod_map;
5967         const char *ret = NULL;
5968 
5969         /* mod_map is freed via call_rcu_sched() */
5970         preempt_disable();
5971         list_for_each_entry_rcu(mod_map, &ftrace_mod_maps, list) {
5972                 ret = ftrace_func_address_lookup(mod_map, addr, size, off, sym);
5973                 if (ret) {
5974                         if (modname)
5975                                 *modname = mod_map->mod->name;
5976                         break;
5977                 }
5978         }
5979         preempt_enable();
5980 
5981         return ret;
5982 }
5983 
5984 int ftrace_mod_get_kallsym(unsigned int symnum, unsigned long *value,
5985                            char *type, char *name,
5986                            char *module_name, int *exported)
5987 {
5988         struct ftrace_mod_map *mod_map;
5989         struct ftrace_mod_func *mod_func;
5990 
5991         preempt_disable();
5992         list_for_each_entry_rcu(mod_map, &ftrace_mod_maps, list) {
5993 
5994                 if (symnum >= mod_map->num_funcs) {
5995                         symnum -= mod_map->num_funcs;
5996                         continue;
5997                 }
5998 
5999                 list_for_each_entry_rcu(mod_func, &mod_map->funcs, list) {
6000                         if (symnum > 1) {
6001                                 symnum--;
6002                                 continue;
6003                         }
6004 
6005                         *value = mod_func->ip;
6006                         *type = 'T';
6007                         strlcpy(name, mod_func->name, KSYM_NAME_LEN);
6008                         strlcpy(module_name, mod_map->mod->name, MODULE_NAME_LEN);
6009                         *exported = 1;
6010                         preempt_enable();
6011                         return 0;
6012                 }
6013                 WARN_ON(1);
6014                 break;
6015         }
6016         preempt_enable();
6017         return -ERANGE;
6018 }
6019 
6020 #else
6021 static void save_ftrace_mod_rec(struct ftrace_mod_map *mod_map,
6022                                 struct dyn_ftrace *rec) { }
6023 static inline struct ftrace_mod_map *
6024 allocate_ftrace_mod_map(struct module *mod,
6025                         unsigned long start, unsigned long end)
6026 {
6027         return NULL;
6028 }
6029 #endif /* CONFIG_MODULES */
6030 
6031 struct ftrace_init_func {
6032         struct list_head list;
6033         unsigned long ip;
6034 };
6035 
6036 /* Clear any init ips from hashes */
6037 static void
6038 clear_func_from_hash(struct ftrace_init_func *func, struct ftrace_hash *hash)
6039 {
6040         struct ftrace_func_entry *entry;
6041 
6042         if (ftrace_hash_empty(hash))
6043                 return;
6044 
6045         entry = __ftrace_lookup_ip(hash, func->ip);
6046 
6047         /*
6048          * Do not allow this rec to match again.
6049          * Yeah, it may waste some memory, but will be removed
6050          * if/when the hash is modified again.
6051          */
6052         if (entry)
6053                 entry->ip = 0;
6054 }
6055 
6056 static void
6057 clear_func_from_hashes(struct ftrace_init_func *func)
6058 {
6059         struct trace_array *tr;
6060 
6061         mutex_lock(&trace_types_lock);
6062         list_for_each_entry(tr, &ftrace_trace_arrays, list) {
6063                 if (!tr->ops || !tr->ops->func_hash)
6064                         continue;
6065                 mutex_lock(&tr->ops->func_hash->regex_lock);
6066                 clear_func_from_hash(func, tr->ops->func_hash->filter_hash);
6067                 clear_func_from_hash(func, tr->ops->func_hash->notrace_hash);
6068                 mutex_unlock(&tr->ops->func_hash->regex_lock);
6069         }
6070         mutex_unlock(&trace_types_lock);
6071 }
6072 
6073 static void add_to_clear_hash_list(struct list_head *clear_list,
6074                                    struct dyn_ftrace *rec)
6075 {
6076         struct ftrace_init_func *func;
6077 
6078         func = kmalloc(sizeof(*func), GFP_KERNEL);
6079         if (!func) {
6080                 WARN_ONCE(1, "alloc failure, ftrace filter could be stale\n");
6081                 return;
6082         }
6083 
6084         func->ip = rec->ip;
6085         list_add(&func->list, clear_list);
6086 }
6087 
6088 void ftrace_free_mem(struct module *mod, void *start_ptr, void *end_ptr)
6089 {
6090         unsigned long start = (unsigned long)(start_ptr);
6091         unsigned long end = (unsigned long)(end_ptr);
6092         struct ftrace_page **last_pg = &ftrace_pages_start;
6093         struct ftrace_page *pg;
6094         struct dyn_ftrace *rec;
6095         struct dyn_ftrace key;
6096         struct ftrace_mod_map *mod_map = NULL;
6097         struct ftrace_init_func *func, *func_next;
6098         struct list_head clear_hash;
6099         int order;
6100 
6101         INIT_LIST_HEAD(&clear_hash);
6102 
6103         key.ip = start;
6104         key.flags = end;        /* overload flags, as it is unsigned long */
6105 
6106         mutex_lock(&ftrace_lock);
6107 
6108         /*
6109          * If we are freeing module init memory, then check if
6110          * any tracer is active. If so, we need to save a mapping of
6111          * the module functions being freed with the address.
6112          */
6113         if (mod && ftrace_ops_list != &ftrace_list_end)
6114                 mod_map = allocate_ftrace_mod_map(mod, start, end);
6115 
6116         for (pg = ftrace_pages_start; pg; last_pg = &pg->next, pg = *last_pg) {
6117                 if (end < pg->records[0].ip ||
6118                     start >= (pg->records[pg->index - 1].ip + MCOUNT_INSN_SIZE))
6119                         continue;
6120  again:
6121                 rec = bsearch(&key, pg->records, pg->index,
6122                               sizeof(struct dyn_ftrace),
6123                               ftrace_cmp_recs);
6124                 if (!rec)
6125                         continue;
6126 
6127                 /* rec will be cleared from hashes after ftrace_lock unlock */
6128                 add_to_clear_hash_list(&clear_hash, rec);
6129 
6130                 if (mod_map)
6131                         save_ftrace_mod_rec(mod_map, rec);
6132 
6133                 pg->index--;
6134                 ftrace_update_tot_cnt--;
6135                 if (!pg->index) {
6136                         *last_pg = pg->next;
6137                         order = get_count_order(pg->size / ENTRIES_PER_PAGE);
6138                         free_pages((unsigned long)pg->records, order);
6139                         kfree(pg);
6140                         pg = container_of(last_pg, struct ftrace_page, next);
6141                         if (!(*last_pg))
6142                                 ftrace_pages = pg;
6143                         continue;
6144                 }
6145                 memmove(rec, rec + 1,
6146                         (pg->index - (rec - pg->records)) * sizeof(*rec));
6147                 /* More than one function may be in this block */
6148                 goto again;
6149         }
6150         mutex_unlock(&ftrace_lock);
6151 
6152         list_for_each_entry_safe(func, func_next, &clear_hash, list) {
6153                 clear_func_from_hashes(func);
6154                 kfree(func);
6155         }
6156 }
6157 
6158 void __init ftrace_free_init_mem(void)
6159 {
6160         void *start = (void *)(&__init_begin);
6161         void *end = (void *)(&__init_end);
6162 
6163         ftrace_free_mem(NULL, start, end);
6164 }
6165 
6166 void __init ftrace_init(void)
6167 {
6168         extern unsigned long __start_mcount_loc[];
6169         extern unsigned long __stop_mcount_loc[];
6170         unsigned long count, flags;
6171         int ret;
6172 
6173         local_irq_save(flags);
6174         ret = ftrace_dyn_arch_init();
6175         local_irq_restore(flags);
6176         if (ret)
6177                 goto failed;
6178 
6179         count = __stop_mcount_loc - __start_mcount_loc;
6180         if (!count) {
6181                 pr_info("ftrace: No functions to be traced?\n");
6182                 goto failed;
6183         }
6184 
6185         pr_info("ftrace: allocating %ld entries in %ld pages\n",
6186                 count, count / ENTRIES_PER_PAGE + 1);
6187 
6188         last_ftrace_enabled = ftrace_enabled = 1;
6189 
6190         ret = ftrace_process_locs(NULL,
6191                                   __start_mcount_loc,
6192                                   __stop_mcount_loc);
6193 
6194         set_ftrace_early_filters();
6195 
6196         return;
6197  failed:
6198         ftrace_disabled = 1;
6199 }
6200 
6201 /* Do nothing if arch does not support this */
6202 void __weak arch_ftrace_update_trampoline(struct ftrace_ops *ops)
6203 {
6204 }
6205 
6206 static void ftrace_update_trampoline(struct ftrace_ops *ops)
6207 {
6208         arch_ftrace_update_trampoline(ops);
6209 }
6210 
6211 void ftrace_init_trace_array(struct trace_array *tr)
6212 {
6213         INIT_LIST_HEAD(&tr->func_probes);
6214         INIT_LIST_HEAD(&tr->mod_trace);
6215         INIT_LIST_HEAD(&tr->mod_notrace);
6216 }
6217 #else
6218 
6219 static struct ftrace_ops global_ops = {
6220         .func                   = ftrace_stub,
6221         .flags                  = FTRACE_OPS_FL_RECURSION_SAFE |
6222                                   FTRACE_OPS_FL_INITIALIZED |
6223                                   FTRACE_OPS_FL_PID,
6224 };
6225 
6226 static int __init ftrace_nodyn_init(void)
6227 {
6228         ftrace_enabled = 1;
6229         return 0;
6230 }
6231 core_initcall(ftrace_nodyn_init);
6232 
6233 static inline int ftrace_init_dyn_tracefs(struct dentry *d_tracer) { return 0; }
6234 static inline void ftrace_startup_enable(int command) { }
6235 static inline void ftrace_startup_all(int command) { }
6236 /* Keep as macros so we do not need to define the commands */
6237 # define ftrace_startup(ops, command)                                   \
6238         ({                                                              \
6239                 int ___ret = __register_ftrace_function(ops);           \
6240                 if (!___ret)                                            \
6241                         (ops)->flags |= FTRACE_OPS_FL_ENABLED;          \
6242                 ___ret;                                                 \
6243         })
6244 # define ftrace_shutdown(ops, command)                                  \
6245         ({                                                              \
6246                 int ___ret = __unregister_ftrace_function(ops);         \
6247                 if (!___ret)                                            \
6248                         (ops)->flags &= ~FTRACE_OPS_FL_ENABLED;         \
6249                 ___ret;                                                 \
6250         })
6251 
6252 # define ftrace_startup_sysctl()        do { } while (0)
6253 # define ftrace_shutdown_sysctl()       do { } while (0)
6254 
6255 static inline int
6256 ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip, void *regs)
6257 {
6258         return 1;
6259 }
6260 
6261 static void ftrace_update_trampoline(struct ftrace_ops *ops)
6262 {
6263 }
6264 
6265 #endif /* CONFIG_DYNAMIC_FTRACE */
6266 
6267 __init void ftrace_init_global_array_ops(struct trace_array *tr)
6268 {
6269         tr->ops = &global_ops;
6270         tr->ops->private = tr;
6271         ftrace_init_trace_array(tr);
6272 }
6273 
6274 void ftrace_init_array_ops(struct trace_array *tr, ftrace_func_t func)
6275 {
6276         /* If we filter on pids, update to use the pid function */
6277         if (tr->flags & TRACE_ARRAY_FL_GLOBAL) {
6278                 if (WARN_ON(tr->ops->func != ftrace_stub))
6279                         printk("ftrace ops had %pS for function\n",
6280                                tr->ops->func);
6281         }
6282         tr->ops->func = func;
6283         tr->ops->private = tr;
6284 }
6285 
6286 void ftrace_reset_array_ops(struct trace_array *tr)
6287 {
6288         tr->ops->func = ftrace_stub;
6289 }
6290 
6291 static inline void
6292 __ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
6293                        struct ftrace_ops *ignored, struct pt_regs *regs)
6294 {
6295         struct ftrace_ops *op;
6296         int bit;
6297 
6298         bit = trace_test_and_set_recursion(TRACE_LIST_START, TRACE_LIST_MAX);
6299         if (bit < 0)
6300                 return;
6301 
6302         /*
6303          * Some of the ops may be dynamically allocated,
6304          * they must be freed after a synchronize_sched().
6305          */
6306         preempt_disable_notrace();
6307 
6308         do_for_each_ftrace_op(op, ftrace_ops_list) {
6309                 /*
6310                  * Check the following for each ops before calling their func:
6311                  *  if RCU flag is set, then rcu_is_watching() must be true
6312                  *  if PER_CPU is set, then ftrace_function_local_disable()
6313                  *                          must be false
6314                  *  Otherwise test if the ip matches the ops filter
6315                  *
6316                  * If any of the above fails then the op->func() is not executed.
6317                  */
6318                 if ((!(op->flags & FTRACE_OPS_FL_RCU) || rcu_is_watching()) &&
6319                     ftrace_ops_test(op, ip, regs)) {
6320                         if (FTRACE_WARN_ON(!op->func)) {
6321                                 pr_warn("op=%p %pS\n", op, op);
6322                                 goto out;
6323                         }
6324                         op->func(ip, parent_ip, op, regs);
6325                 }
6326         } while_for_each_ftrace_op(op);
6327 out:
6328         preempt_enable_notrace();
6329         trace_clear_recursion(bit);
6330 }
6331 
6332 /*
6333  * Some archs only support passing ip and parent_ip. Even though
6334  * the list function ignores the op parameter, we do not want any
6335  * C side effects, where a function is called without the caller
6336  * sending a third parameter.
6337  * Archs are to support both the regs and ftrace_ops at the same time.
6338  * If they support ftrace_ops, it is assumed they support regs.
6339  * If call backs want to use regs, they must either check for regs
6340  * being NULL, or CONFIG_DYNAMIC_FTRACE_WITH_REGS.
6341  * Note, CONFIG_DYNAMIC_FTRACE_WITH_REGS expects a full regs to be saved.
6342  * An architecture can pass partial regs with ftrace_ops and still
6343  * set the ARCH_SUPPORTS_FTRACE_OPS.
6344  */
6345 #if ARCH_SUPPORTS_FTRACE_OPS
6346 static void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
6347                                  struct ftrace_ops *op, struct pt_regs *regs)
6348 {
6349         __ftrace_ops_list_func(ip, parent_ip, NULL, regs);
6350 }
6351 #else
6352 static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip)
6353 {
6354         __ftrace_ops_list_func(ip, parent_ip, NULL, NULL);
6355 }
6356 #endif
6357 
6358 /*
6359  * If there's only one function registered but it does not support
6360  * recursion, needs RCU protection and/or requires per cpu handling, then
6361  * this function will be called by the mcount trampoline.
6362  */
6363 static void ftrace_ops_assist_func(unsigned long ip, unsigned long parent_ip,
6364                                    struct ftrace_ops *op, struct pt_regs *regs)
6365 {
6366         int bit;
6367 
6368         if ((op->flags & FTRACE_OPS_FL_RCU) && !rcu_is_watching())
6369                 return;
6370 
6371         bit = trace_test_and_set_recursion(TRACE_LIST_START, TRACE_LIST_MAX);
6372         if (bit < 0)
6373                 return;
6374 
6375         preempt_disable_notrace();
6376 
6377         op->func(ip, parent_ip, op, regs);
6378 
6379         preempt_enable_notrace();
6380         trace_clear_recursion(bit);
6381 }
6382 
6383 /**
6384  * ftrace_ops_get_func - get the function a trampoline should call
6385  * @ops: the ops to get the function for
6386  *
6387  * Normally the mcount trampoline will call the ops->func, but there
6388  * are times that it should not. For example, if the ops does not
6389  * have its own recursion protection, then it should call the
6390  * ftrace_ops_assist_func() instead.
6391  *
6392  * Returns the function that the trampoline should call for @ops.
6393  */
6394 ftrace_func_t ftrace_ops_get_func(struct ftrace_ops *ops)
6395 {
6396         /*
6397          * If the function does not handle recursion, needs to be RCU safe,
6398          * or does per cpu logic, then we need to call the assist handler.
6399          */
6400         if (!(ops->flags & FTRACE_OPS_FL_RECURSION_SAFE) ||
6401             ops->flags & FTRACE_OPS_FL_RCU)
6402                 return ftrace_ops_assist_func;
6403 
6404         return ops->func;
6405 }
6406 
6407 static void
6408 ftrace_filter_pid_sched_switch_probe(void *data, bool preempt,
6409                     struct task_struct *prev, struct task_struct *next)
6410 {
6411         struct trace_array *tr = data;
6412         struct trace_pid_list *pid_list;
6413 
6414         pid_list = rcu_dereference_sched(tr->function_pids);
6415 
6416         this_cpu_write(tr->trace_buffer.data->ftrace_ignore_pid,
6417                        trace_ignore_this_task(pid_list, next));
6418 }
6419 
6420 static void
6421 ftrace_pid_follow_sched_process_fork(void *data,
6422                                      struct task_struct *self,
6423                                      struct task_struct *task)
6424 {
6425         struct trace_pid_list *pid_list;
6426         struct trace_array *tr = data;
6427 
6428         pid_list = rcu_dereference_sched(tr->function_pids);
6429         trace_filter_add_remove_task(pid_list, self, task);
6430 }
6431 
6432 static void
6433 ftrace_pid_follow_sched_process_exit(void *data, struct task_struct *task)
6434 {
6435         struct trace_pid_list *pid_list;
6436         struct trace_array *tr = data;
6437 
6438         pid_list = rcu_dereference_sched(tr->function_pids);
6439         trace_filter_add_remove_task(pid_list, NULL, task);
6440 }
6441 
6442 void ftrace_pid_follow_fork(struct trace_array *tr, bool enable)
6443 {
6444         if (enable) {
6445                 register_trace_sched_process_fork(ftrace_pid_follow_sched_process_fork,
6446                                                   tr);
6447                 register_trace_sched_process_exit(ftrace_pid_follow_sched_process_exit,
6448                                                   tr);
6449         } else {
6450                 unregister_trace_sched_process_fork(ftrace_pid_follow_sched_process_fork,
6451                                                     tr);
6452                 unregister_trace_sched_process_exit(ftrace_pid_follow_sched_process_exit,
6453                                                     tr);
6454         }
6455 }
6456 
6457 static void clear_ftrace_pids(struct trace_array *tr)
6458 {
6459         struct trace_pid_list *pid_list;
6460         int cpu;
6461 
6462         pid_list = rcu_dereference_protected(tr->function_pids,
6463                                              lockdep_is_held(&ftrace_lock));
6464         if (!pid_list)
6465                 return;
6466 
6467         unregister_trace_sched_switch(ftrace_filter_pid_sched_switch_probe, tr);
6468 
6469         for_each_possible_cpu(cpu)
6470                 per_cpu_ptr(tr->trace_buffer.data, cpu)->ftrace_ignore_pid = false;
6471 
6472         rcu_assign_pointer(tr->function_pids, NULL);
6473 
6474         /* Wait till all users are no longer using pid filtering */
6475         synchronize_sched();
6476 
6477         trace_free_pid_list(pid_list);
6478 }
6479 
6480 void ftrace_clear_pids(struct trace_array *tr)
6481 {
6482         mutex_lock(&ftrace_lock);
6483 
6484         clear_ftrace_pids(tr);
6485 
6486         mutex_unlock(&ftrace_lock);
6487 }
6488 
6489 static void ftrace_pid_reset(struct trace_array *tr)
6490 {
6491         mutex_lock(&ftrace_lock);
6492         clear_ftrace_pids(tr);
6493 
6494         ftrace_update_pid_func();
6495         ftrace_startup_all(0);
6496 
6497         mutex_unlock(&ftrace_lock);
6498 }
6499 
6500 /* Greater than any max PID */
6501 #define FTRACE_NO_PIDS          (void *)(PID_MAX_LIMIT + 1)
6502 
6503 static void *fpid_start(struct seq_file *m, loff_t *pos)
6504         __acquires(RCU)
6505 {
6506         struct trace_pid_list *pid_list;
6507         struct trace_array *tr = m->private;
6508 
6509         mutex_lock(&ftrace_lock);
6510         rcu_read_lock_sched();
6511 
6512         pid_list = rcu_dereference_sched(tr->function_pids);
6513 
6514         if (!pid_list)
6515                 return !(*pos) ? FTRACE_NO_PIDS : NULL;
6516 
6517         return trace_pid_start(pid_list, pos);
6518 }
6519 
6520 static void *fpid_next(struct seq_file *m, void *v, loff_t *pos)
6521 {
6522         struct trace_array *tr = m->private;
6523         struct trace_pid_list *pid_list = rcu_dereference_sched(tr->function_pids);
6524 
6525         if (v == FTRACE_NO_PIDS)
6526                 return NULL;
6527 
6528         return trace_pid_next(pid_list, v, pos);
6529 }
6530 
6531 static void fpid_stop(struct seq_file *m, void *p)
6532         __releases(RCU)
6533 {
6534         rcu_read_unlock_sched();
6535         mutex_unlock(&ftrace_lock);
6536 }
6537 
6538 static int fpid_show(struct seq_file *m, void *v)
6539 {
6540         if (v == FTRACE_NO_PIDS) {
6541                 seq_puts(m, "no pid\n");
6542                 return 0;
6543         }
6544 
6545         return trace_pid_show(m, v);
6546 }
6547 
6548 static const struct seq_operations ftrace_pid_sops = {
6549         .start = fpid_start,
6550         .next = fpid_next,
6551         .stop = fpid_stop,
6552         .show = fpid_show,
6553 };
6554 
6555 static int
6556 ftrace_pid_open(struct inode *inode, struct file *file)
6557 {
6558         struct trace_array *tr = inode->i_private;
6559         struct seq_file *m;
6560         int ret = 0;
6561 
6562         if (trace_array_get(tr) < 0)
6563                 return -ENODEV;
6564 
6565         if ((file->f_mode & FMODE_WRITE) &&
6566             (file->f_flags & O_TRUNC))
6567                 ftrace_pid_reset(tr);
6568 
6569         ret = seq_open(file, &ftrace_pid_sops);
6570         if (ret < 0) {
6571                 trace_array_put(tr);
6572         } else {
6573                 m = file->private_data;
6574                 /* copy tr over to seq ops */
6575                 m->private = tr;
6576         }
6577 
6578         return ret;
6579 }
6580 
6581 static void ignore_task_cpu(void *data)
6582 {
6583         struct trace_array *tr = data;
6584         struct trace_pid_list *pid_list;
6585 
6586         /*
6587          * This function is called by on_each_cpu() while the
6588          * event_mutex is held.
6589          */
6590         pid_list = rcu_dereference_protected(tr->function_pids,
6591                                              mutex_is_locked(&ftrace_lock));
6592 
6593         this_cpu_write(tr->trace_buffer.data->ftrace_ignore_pid,
6594                        trace_ignore_this_task(pid_list, current));
6595 }
6596 
6597 static ssize_t
6598 ftrace_pid_write(struct file *filp, const char __user *ubuf,
6599                    size_t cnt, loff_t *ppos)
6600 {
6601         struct seq_file *m = filp->private_data;
6602         struct trace_array *tr = m->private;
6603         struct trace_pid_list *filtered_pids = NULL;
6604         struct trace_pid_list *pid_list;
6605         ssize_t ret;
6606 
6607         if (!cnt)
6608                 return 0;
6609 
6610         mutex_lock(&ftrace_lock);
6611 
6612         filtered_pids = rcu_dereference_protected(tr->function_pids,
6613                                              lockdep_is_held(&ftrace_lock));
6614 
6615         ret = trace_pid_write(filtered_pids, &pid_list, ubuf, cnt);
6616         if (ret < 0)
6617                 goto out;
6618 
6619         rcu_assign_pointer(tr->function_pids, pid_list);
6620 
6621         if (filtered_pids) {
6622                 synchronize_sched();
6623                 trace_free_pid_list(filtered_pids);
6624         } else if (pid_list) {
6625                 /* Register a probe to set whether to ignore the tracing of a task */
6626                 register_trace_sched_switch(ftrace_filter_pid_sched_switch_probe, tr);
6627         }
6628 
6629         /*
6630          * Ignoring of pids is done at task switch. But we have to
6631          * check for those tasks that are currently running.
6632          * Always do this in case a pid was appended or removed.
6633          */
6634         on_each_cpu(ignore_task_cpu, tr, 1);
6635 
6636         ftrace_update_pid_func();
6637         ftrace_startup_all(0);
6638  out:
6639         mutex_unlock(&ftrace_lock);
6640 
6641         if (ret > 0)
6642                 *ppos += ret;
6643 
6644         return ret;
6645 }
6646 
6647 static int
6648 ftrace_pid_release(struct inode *inode, struct file *file)
6649 {
6650         struct trace_array *tr = inode->i_private;
6651 
6652         trace_array_put(tr);
6653 
6654         return seq_release(inode, file);
6655 }
6656 
6657 static const struct file_operations ftrace_pid_fops = {
6658         .open           = ftrace_pid_open,
6659         .write          = ftrace_pid_write,
6660         .read           = seq_read,
6661         .llseek         = tracing_lseek,
6662         .release        = ftrace_pid_release,
6663 };
6664 
6665 void ftrace_init_tracefs(struct trace_array *tr, struct dentry *d_tracer)
6666 {
6667         trace_create_file("set_ftrace_pid", 0644, d_tracer,
6668                             tr, &ftrace_pid_fops);
6669 }
6670 
6671 void __init ftrace_init_tracefs_toplevel(struct trace_array *tr,
6672                                          struct dentry *d_tracer)
6673 {
6674         /* Only the top level directory has the dyn_tracefs and profile */
6675         WARN_ON(!(tr->flags & TRACE_ARRAY_FL_GLOBAL));
6676 
6677         ftrace_init_dyn_tracefs(d_tracer);
6678         ftrace_profile_tracefs(d_tracer);
6679 }
6680 
6681 /**
6682  * ftrace_kill - kill ftrace
6683  *
6684  * This function should be used by panic code. It stops ftrace
6685  * but in a not so nice way. If you need to simply kill ftrace
6686  * from a non-atomic section, use ftrace_kill.
6687  */
6688 void ftrace_kill(void)
6689 {
6690         ftrace_disabled = 1;
6691         ftrace_enabled = 0;
6692         clear_ftrace_function();
6693 }
6694 
6695 /**
6696  * Test if ftrace is dead or not.
6697  */
6698 int ftrace_is_dead(void)
6699 {
6700         return ftrace_disabled;
6701 }
6702 
6703 /**
6704  * register_ftrace_function - register a function for profiling
6705  * @ops - ops structure that holds the function for profiling.
6706  *
6707  * Register a function to be called by all functions in the
6708  * kernel.
6709  *
6710  * Note: @ops->func and all the functions it calls must be labeled
6711  *       with "notrace", otherwise it will go into a
6712  *       recursive loop.
6713  */
6714 int register_ftrace_function(struct ftrace_ops *ops)
6715 {
6716         int ret = -1;
6717 
6718         ftrace_ops_init(ops);
6719 
6720         mutex_lock(&ftrace_lock);
6721 
6722         ret = ftrace_startup(ops, 0);
6723 
6724         mutex_unlock(&ftrace_lock);
6725 
6726         return ret;
6727 }
6728 EXPORT_SYMBOL_GPL(register_ftrace_function);
6729 
6730 /**
6731  * unregister_ftrace_function - unregister a function for profiling.
6732  * @ops - ops structure that holds the function to unregister
6733  *
6734  * Unregister a function that was added to be called by ftrace profiling.
6735  */
6736 int unregister_ftrace_function(struct ftrace_ops *ops)
6737 {
6738         int ret;
6739 
6740         mutex_lock(&ftrace_lock);
6741         ret = ftrace_shutdown(ops, 0);
6742         mutex_unlock(&ftrace_lock);
6743 
6744         return ret;
6745 }
6746 EXPORT_SYMBOL_GPL(unregister_ftrace_function);
6747 
6748 int
6749 ftrace_enable_sysctl(struct ctl_table *table, int write,
6750                      void __user *buffer, size_t *lenp,
6751                      loff_t *ppos)
6752 {
6753         int ret = -ENODEV;
6754 
6755         mutex_lock(&ftrace_lock);
6756 
6757         if (unlikely(ftrace_disabled))
6758                 goto out;
6759 
6760         ret = proc_dointvec(table, write, buffer, lenp, ppos);
6761 
6762         if (ret || !write || (last_ftrace_enabled == !!ftrace_enabled))
6763                 goto out;
6764 
6765         last_ftrace_enabled = !!ftrace_enabled;
6766 
6767         if (ftrace_enabled) {
6768 
6769                 /* we are starting ftrace again */
6770                 if (rcu_dereference_protected(ftrace_ops_list,
6771                         lockdep_is_held(&ftrace_lock)) != &ftrace_list_end)
6772                         update_ftrace_function();
6773 
6774                 ftrace_startup_sysctl();
6775 
6776         } else {
6777                 /* stopping ftrace calls (just send to ftrace_stub) */
6778                 ftrace_trace_function = ftrace_stub;
6779 
6780                 ftrace_shutdown_sysctl();
6781         }
6782 
6783  out:
6784         mutex_unlock(&ftrace_lock);
6785         return ret;
6786 }
6787 
6788 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
6789 
6790 static struct ftrace_ops graph_ops = {
6791         .func                   = ftrace_stub,
6792         .flags                  = FTRACE_OPS_FL_RECURSION_SAFE |
6793                                    FTRACE_OPS_FL_INITIALIZED |
6794                                    FTRACE_OPS_FL_PID |
6795                                    FTRACE_OPS_FL_STUB,
6796 #ifdef FTRACE_GRAPH_TRAMP_ADDR
6797         .trampoline             = FTRACE_GRAPH_TRAMP_ADDR,
6798         /* trampoline_size is only needed for dynamically allocated tramps */
6799 #endif
6800         ASSIGN_OPS_HASH(graph_ops, &global_ops.local_hash)
6801 };
6802 
6803 void ftrace_graph_sleep_time_control(bool enable)
6804 {
6805         fgraph_sleep_time = enable;
6806 }
6807 
6808 void ftrace_graph_graph_time_control(bool enable)
6809 {
6810         fgraph_graph_time = enable;
6811 }
6812 
6813 int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace)
6814 {
6815         return 0;
6816 }
6817 
6818 /* The callbacks that hook a function */
6819 trace_func_graph_ret_t ftrace_graph_return =
6820                         (trace_func_graph_ret_t)ftrace_stub;
6821 trace_func_graph_ent_t ftrace_graph_entry = ftrace_graph_entry_stub;
6822 static trace_func_graph_ent_t __ftrace_graph_entry = ftrace_graph_entry_stub;
6823 
6824 /* Try to assign a return stack array on FTRACE_RETSTACK_ALLOC_SIZE tasks. */
6825 static int alloc_retstack_tasklist(struct ftrace_ret_stack **ret_stack_list)
6826 {
6827         int i;
6828         int ret = 0;
6829         int start = 0, end = FTRACE_RETSTACK_ALLOC_SIZE;
6830         struct task_struct *g, *t;
6831 
6832         for (i = 0; i < FTRACE_RETSTACK_ALLOC_SIZE; i++) {
6833                 ret_stack_list[i] =
6834                         kmalloc_array(FTRACE_RETFUNC_DEPTH,
6835                                       sizeof(struct ftrace_ret_stack),
6836                                       GFP_KERNEL);
6837                 if (!ret_stack_list[i]) {
6838                         start = 0;
6839                         end = i;
6840                         ret = -ENOMEM;
6841                         goto free;
6842                 }
6843         }
6844 
6845         read_lock(&tasklist_lock);
6846         do_each_thread(g, t) {
6847                 if (start == end) {
6848                         ret = -EAGAIN;
6849                         goto unlock;
6850                 }
6851 
6852                 if (t->ret_stack == NULL) {
6853                         atomic_set(&t->tracing_graph_pause, 0);
6854                         atomic_set(&t->trace_overrun, 0);
6855                         t->curr_ret_stack = -1;
6856                         /* Make sure the tasks see the -1 first: */
6857                         smp_wmb();
6858                         t->ret_stack = ret_stack_list[start++];
6859                 }
6860         } while_each_thread(g, t);
6861 
6862 unlock:
6863         read_unlock(&tasklist_lock);
6864 free:
6865         for (i = start; i < end; i++)
6866                 kfree(ret_stack_list[i]);
6867         return ret;
6868 }
6869 
6870 static void
6871 ftrace_graph_probe_sched_switch(void *ignore, bool preempt,
6872                         struct task_struct *prev, struct task_struct *next)
6873 {
6874         unsigned long long timestamp;
6875         int index;
6876 
6877         /*
6878          * Does the user want to count the time a function was asleep.
6879          * If so, do not update the time stamps.
6880          */
6881         if (fgraph_sleep_time)
6882                 return;
6883 
6884         timestamp = trace_clock_local();
6885 
6886         prev->ftrace_timestamp = timestamp;
6887 
6888         /* only process tasks that we timestamped */
6889         if (!next->ftrace_timestamp)
6890                 return;
6891 
6892         /*
6893          * Update all the counters in next to make up for the
6894          * time next was sleeping.
6895          */
6896         timestamp -= next->ftrace_timestamp;
6897 
6898         for (index = next->curr_ret_stack; index >= 0; index--)
6899                 next->ret_stack[index].calltime += timestamp;
6900 }
6901 
6902 /* Allocate a return stack for each task */
6903 static int start_graph_tracing(void)
6904 {
6905         struct ftrace_ret_stack **ret_stack_list;
6906         int ret, cpu;
6907 
6908         ret_stack_list = kmalloc_array(FTRACE_RETSTACK_ALLOC_SIZE,
6909                                        sizeof(struct ftrace_ret_stack *),
6910                                        GFP_KERNEL);
6911 
6912         if (!ret_stack_list)
6913                 return -ENOMEM;
6914 
6915         /* The cpu_boot init_task->ret_stack will never be freed */
6916         for_each_online_cpu(cpu) {
6917                 if (!idle_task(cpu)->ret_stack)
6918                         ftrace_graph_init_idle_task(idle_task(cpu), cpu);
6919         }
6920 
6921         do {
6922                 ret = alloc_retstack_tasklist(ret_stack_list);
6923         } while (ret == -EAGAIN);
6924 
6925         if (!ret) {
6926                 ret = register_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL);
6927                 if (ret)
6928                         pr_info("ftrace_graph: Couldn't activate tracepoint"
6929                                 " probe to kernel_sched_switch\n");
6930         }
6931 
6932         kfree(ret_stack_list);
6933         return ret;
6934 }
6935 
6936 /*
6937  * Hibernation protection.
6938  * The state of the current task is too much unstable during
6939  * suspend/restore to disk. We want to protect against that.
6940  */
6941 static int
6942 ftrace_suspend_notifier_call(struct notifier_block *bl, unsigned long state,
6943                                                         void *unused)
6944 {
6945         switch (state) {
6946         case PM_HIBERNATION_PREPARE:
6947                 pause_graph_tracing();
6948                 break;
6949 
6950         case PM_POST_HIBERNATION:
6951                 unpause_graph_tracing();
6952                 break;
6953         }
6954         return NOTIFY_DONE;
6955 }
6956 
6957 static int ftrace_graph_entry_test(struct ftrace_graph_ent *trace)
6958 {
6959         if (!ftrace_ops_test(&global_ops, trace->func, NULL))
6960                 return 0;
6961         return __ftrace_graph_entry(trace);
6962 }
6963 
6964 /*
6965  * The function graph tracer should only trace the functions defined
6966  * by set_ftrace_filter and set_ftrace_notrace. If another function
6967  * tracer ops is registered, the graph tracer requires testing the
6968  * function against the global ops, and not just trace any function
6969  * that any ftrace_ops registered.
6970  */
6971 static void update_function_graph_func(void)
6972 {
6973         struct ftrace_ops *op;
6974         bool do_test = false;
6975 
6976         /*
6977          * The graph and global ops share the same set of functions
6978          * to test. If any other ops is on the list, then
6979          * the graph tracing needs to test if its the function
6980          * it should call.
6981          */
6982         do_for_each_ftrace_op(op, ftrace_ops_list) {
6983                 if (op != &global_ops && op != &graph_ops &&
6984                     op != &ftrace_list_end) {
6985                         do_test = true;
6986                         /* in double loop, break out with goto */
6987                         goto out;
6988                 }
6989         } while_for_each_ftrace_op(op);
6990  out:
6991         if (do_test)
6992                 ftrace_graph_entry = ftrace_graph_entry_test;
6993         else
6994                 ftrace_graph_entry = __ftrace_graph_entry;
6995 }
6996 
6997 static struct notifier_block ftrace_suspend_notifier = {
6998         .notifier_call = ftrace_suspend_notifier_call,
6999 };
7000 
7001 int register_ftrace_graph(trace_func_graph_ret_t retfunc,
7002                         trace_func_graph_ent_t entryfunc)
7003 {
7004         int ret = 0;
7005 
7006         mutex_lock(&ftrace_lock);
7007 
7008         /* we currently allow only one tracer registered at a time */
7009         if (ftrace_graph_active) {
7010                 ret = -EBUSY;
7011                 goto out;
7012         }
7013 
7014         register_pm_notifier(&ftrace_suspend_notifier);
7015 
7016         ftrace_graph_active++;
7017         ret = start_graph_tracing();
7018         if (ret) {
7019                 ftrace_graph_active--;
7020                 goto out;
7021         }
7022 
7023         ftrace_graph_return = retfunc;
7024 
7025         /*
7026          * Update the indirect function to the entryfunc, and the
7027          * function that gets called to the entry_test first. Then
7028          * call the update fgraph entry function to determine if
7029          * the entryfunc should be called directly or not.
7030          */
7031         __ftrace_graph_entry = entryfunc;
7032         ftrace_graph_entry = ftrace_graph_entry_test;
7033         update_function_graph_func();
7034 
7035         ret = ftrace_startup(&graph_ops, FTRACE_START_FUNC_RET);
7036 out:
7037         mutex_unlock(&ftrace_lock);
7038         return ret;
7039 }
7040 
7041 void unregister_ftrace_graph(void)
7042 {
7043         mutex_lock(&ftrace_lock);
7044 
7045         if (unlikely(!ftrace_graph_active))
7046                 goto out;
7047 
7048         ftrace_graph_active--;
7049         ftrace_graph_return = (trace_func_graph_ret_t)ftrace_stub;
7050         ftrace_graph_entry = ftrace_graph_entry_stub;
7051         __ftrace_graph_entry = ftrace_graph_entry_stub;
7052         ftrace_shutdown(&graph_ops, FTRACE_STOP_FUNC_RET);
7053         unregister_pm_notifier(&ftrace_suspend_notifier);
7054         unregister_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL);
7055 
7056  out:
7057         mutex_unlock(&ftrace_lock);
7058 }
7059 
7060 static DEFINE_PER_CPU(struct ftrace_ret_stack *, idle_ret_stack);
7061 
7062 static void
7063 graph_init_task(struct task_struct *t, struct ftrace_ret_stack *ret_stack)
7064 {
7065         atomic_set(&t->tracing_graph_pause, 0);
7066         atomic_set(&t->trace_overrun, 0);
7067         t->ftrace_timestamp = 0;
7068         /* make curr_ret_stack visible before we add the ret_stack */
7069         smp_wmb();
7070         t->ret_stack = ret_stack;
7071 }
7072 
7073 /*
7074  * Allocate a return stack for the idle task. May be the first
7075  * time through, or it may be done by CPU hotplug online.
7076  */
7077 void ftrace_graph_init_idle_task(struct task_struct *t, int cpu)
7078 {
7079         t->curr_ret_stack = -1;
7080         /*
7081          * The idle task has no parent, it either has its own
7082          * stack or no stack at all.
7083          */
7084         if (t->ret_stack)
7085                 WARN_ON(t->ret_stack != per_cpu(idle_ret_stack, cpu));
7086 
7087         if (ftrace_graph_active) {
7088                 struct ftrace_ret_stack *ret_stack;
7089 
7090                 ret_stack = per_cpu(idle_ret_stack, cpu);
7091                 if (!ret_stack) {
7092                         ret_stack =
7093                                 kmalloc_array(FTRACE_RETFUNC_DEPTH,
7094                                               sizeof(struct ftrace_ret_stack),
7095                                               GFP_KERNEL);
7096                         if (!ret_stack)
7097                                 return;
7098                         per_cpu(idle_ret_stack, cpu) = ret_stack;
7099                 }
7100                 graph_init_task(t, ret_stack);
7101         }
7102 }
7103 
7104 /* Allocate a return stack for newly created task */
7105 void ftrace_graph_init_task(struct task_struct *t)
7106 {
7107         /* Make sure we do not use the parent ret_stack */
7108         t->ret_stack = NULL;
7109         t->curr_ret_stack = -1;
7110 
7111         if (ftrace_graph_active) {
7112                 struct ftrace_ret_stack *ret_stack;
7113 
7114                 ret_stack = kmalloc_array(FTRACE_RETFUNC_DEPTH,
7115                                           sizeof(struct ftrace_ret_stack),
7116                                           GFP_KERNEL);
7117                 if (!ret_stack)
7118                         return;
7119                 graph_init_task(t, ret_stack);
7120         }
7121 }
7122 
7123 void ftrace_graph_exit_task(struct task_struct *t)
7124 {
7125         struct ftrace_ret_stack *ret_stack = t->ret_stack;
7126 
7127         t->ret_stack = NULL;
7128         /* NULL must become visible to IRQs before we free it: */
7129         barrier();
7130 
7131         kfree(ret_stack);
7132 }
7133 #endif
7134 

~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

kernel.org | git.kernel.org | LWN.net | Project Home | Wiki (Japanese) | Wiki (English) | SVN repository | Mail admin

Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.

osdn.jp