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Linux/kernel/trace/trace_kprobe.c

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  1 // SPDX-License-Identifier: GPL-2.0
  2 /*
  3  * Kprobes-based tracing events
  4  *
  5  * Created by Masami Hiramatsu <mhiramat@redhat.com>
  6  *
  7  */
  8 #define pr_fmt(fmt)     "trace_kprobe: " fmt
  9 
 10 #include <linux/security.h>
 11 #include <linux/module.h>
 12 #include <linux/uaccess.h>
 13 #include <linux/rculist.h>
 14 #include <linux/error-injection.h>
 15 
 16 #include <asm/setup.h>  /* for COMMAND_LINE_SIZE */
 17 
 18 #include "trace_dynevent.h"
 19 #include "trace_kprobe_selftest.h"
 20 #include "trace_probe.h"
 21 #include "trace_probe_tmpl.h"
 22 
 23 #define KPROBE_EVENT_SYSTEM "kprobes"
 24 #define KRETPROBE_MAXACTIVE_MAX 4096
 25 
 26 /* Kprobe early definition from command line */
 27 static char kprobe_boot_events_buf[COMMAND_LINE_SIZE] __initdata;
 28 
 29 static int __init set_kprobe_boot_events(char *str)
 30 {
 31         strlcpy(kprobe_boot_events_buf, str, COMMAND_LINE_SIZE);
 32         disable_tracing_selftest("running kprobe events");
 33 
 34         return 0;
 35 }
 36 __setup("kprobe_event=", set_kprobe_boot_events);
 37 
 38 static int trace_kprobe_create(const char *raw_command);
 39 static int trace_kprobe_show(struct seq_file *m, struct dyn_event *ev);
 40 static int trace_kprobe_release(struct dyn_event *ev);
 41 static bool trace_kprobe_is_busy(struct dyn_event *ev);
 42 static bool trace_kprobe_match(const char *system, const char *event,
 43                         int argc, const char **argv, struct dyn_event *ev);
 44 
 45 static struct dyn_event_operations trace_kprobe_ops = {
 46         .create = trace_kprobe_create,
 47         .show = trace_kprobe_show,
 48         .is_busy = trace_kprobe_is_busy,
 49         .free = trace_kprobe_release,
 50         .match = trace_kprobe_match,
 51 };
 52 
 53 /*
 54  * Kprobe event core functions
 55  */
 56 struct trace_kprobe {
 57         struct dyn_event        devent;
 58         struct kretprobe        rp;     /* Use rp.kp for kprobe use */
 59         unsigned long __percpu *nhit;
 60         const char              *symbol;        /* symbol name */
 61         struct trace_probe      tp;
 62 };
 63 
 64 static bool is_trace_kprobe(struct dyn_event *ev)
 65 {
 66         return ev->ops == &trace_kprobe_ops;
 67 }
 68 
 69 static struct trace_kprobe *to_trace_kprobe(struct dyn_event *ev)
 70 {
 71         return container_of(ev, struct trace_kprobe, devent);
 72 }
 73 
 74 /**
 75  * for_each_trace_kprobe - iterate over the trace_kprobe list
 76  * @pos:        the struct trace_kprobe * for each entry
 77  * @dpos:       the struct dyn_event * to use as a loop cursor
 78  */
 79 #define for_each_trace_kprobe(pos, dpos)        \
 80         for_each_dyn_event(dpos)                \
 81                 if (is_trace_kprobe(dpos) && (pos = to_trace_kprobe(dpos)))
 82 
 83 #define SIZEOF_TRACE_KPROBE(n)                          \
 84         (offsetof(struct trace_kprobe, tp.args) +       \
 85         (sizeof(struct probe_arg) * (n)))
 86 
 87 static nokprobe_inline bool trace_kprobe_is_return(struct trace_kprobe *tk)
 88 {
 89         return tk->rp.handler != NULL;
 90 }
 91 
 92 static nokprobe_inline const char *trace_kprobe_symbol(struct trace_kprobe *tk)
 93 {
 94         return tk->symbol ? tk->symbol : "unknown";
 95 }
 96 
 97 static nokprobe_inline unsigned long trace_kprobe_offset(struct trace_kprobe *tk)
 98 {
 99         return tk->rp.kp.offset;
100 }
101 
102 static nokprobe_inline bool trace_kprobe_has_gone(struct trace_kprobe *tk)
103 {
104         return !!(kprobe_gone(&tk->rp.kp));
105 }
106 
107 static nokprobe_inline bool trace_kprobe_within_module(struct trace_kprobe *tk,
108                                                  struct module *mod)
109 {
110         int len = strlen(module_name(mod));
111         const char *name = trace_kprobe_symbol(tk);
112 
113         return strncmp(module_name(mod), name, len) == 0 && name[len] == ':';
114 }
115 
116 static nokprobe_inline bool trace_kprobe_module_exist(struct trace_kprobe *tk)
117 {
118         char *p;
119         bool ret;
120 
121         if (!tk->symbol)
122                 return false;
123         p = strchr(tk->symbol, ':');
124         if (!p)
125                 return true;
126         *p = '\0';
127         rcu_read_lock_sched();
128         ret = !!find_module(tk->symbol);
129         rcu_read_unlock_sched();
130         *p = ':';
131 
132         return ret;
133 }
134 
135 static bool trace_kprobe_is_busy(struct dyn_event *ev)
136 {
137         struct trace_kprobe *tk = to_trace_kprobe(ev);
138 
139         return trace_probe_is_enabled(&tk->tp);
140 }
141 
142 static bool trace_kprobe_match_command_head(struct trace_kprobe *tk,
143                                             int argc, const char **argv)
144 {
145         char buf[MAX_ARGSTR_LEN + 1];
146 
147         if (!argc)
148                 return true;
149 
150         if (!tk->symbol)
151                 snprintf(buf, sizeof(buf), "0x%p", tk->rp.kp.addr);
152         else if (tk->rp.kp.offset)
153                 snprintf(buf, sizeof(buf), "%s+%u",
154                          trace_kprobe_symbol(tk), tk->rp.kp.offset);
155         else
156                 snprintf(buf, sizeof(buf), "%s", trace_kprobe_symbol(tk));
157         if (strcmp(buf, argv[0]))
158                 return false;
159         argc--; argv++;
160 
161         return trace_probe_match_command_args(&tk->tp, argc, argv);
162 }
163 
164 static bool trace_kprobe_match(const char *system, const char *event,
165                         int argc, const char **argv, struct dyn_event *ev)
166 {
167         struct trace_kprobe *tk = to_trace_kprobe(ev);
168 
169         return strcmp(trace_probe_name(&tk->tp), event) == 0 &&
170             (!system || strcmp(trace_probe_group_name(&tk->tp), system) == 0) &&
171             trace_kprobe_match_command_head(tk, argc, argv);
172 }
173 
174 static nokprobe_inline unsigned long trace_kprobe_nhit(struct trace_kprobe *tk)
175 {
176         unsigned long nhit = 0;
177         int cpu;
178 
179         for_each_possible_cpu(cpu)
180                 nhit += *per_cpu_ptr(tk->nhit, cpu);
181 
182         return nhit;
183 }
184 
185 static nokprobe_inline bool trace_kprobe_is_registered(struct trace_kprobe *tk)
186 {
187         return !(list_empty(&tk->rp.kp.list) &&
188                  hlist_unhashed(&tk->rp.kp.hlist));
189 }
190 
191 /* Return 0 if it fails to find the symbol address */
192 static nokprobe_inline
193 unsigned long trace_kprobe_address(struct trace_kprobe *tk)
194 {
195         unsigned long addr;
196 
197         if (tk->symbol) {
198                 addr = (unsigned long)
199                         kallsyms_lookup_name(trace_kprobe_symbol(tk));
200                 if (addr)
201                         addr += tk->rp.kp.offset;
202         } else {
203                 addr = (unsigned long)tk->rp.kp.addr;
204         }
205         return addr;
206 }
207 
208 static nokprobe_inline struct trace_kprobe *
209 trace_kprobe_primary_from_call(struct trace_event_call *call)
210 {
211         struct trace_probe *tp;
212 
213         tp = trace_probe_primary_from_call(call);
214         if (WARN_ON_ONCE(!tp))
215                 return NULL;
216 
217         return container_of(tp, struct trace_kprobe, tp);
218 }
219 
220 bool trace_kprobe_on_func_entry(struct trace_event_call *call)
221 {
222         struct trace_kprobe *tk = trace_kprobe_primary_from_call(call);
223 
224         return tk ? (kprobe_on_func_entry(tk->rp.kp.addr,
225                         tk->rp.kp.addr ? NULL : tk->rp.kp.symbol_name,
226                         tk->rp.kp.addr ? 0 : tk->rp.kp.offset) == 0) : false;
227 }
228 
229 bool trace_kprobe_error_injectable(struct trace_event_call *call)
230 {
231         struct trace_kprobe *tk = trace_kprobe_primary_from_call(call);
232 
233         return tk ? within_error_injection_list(trace_kprobe_address(tk)) :
234                false;
235 }
236 
237 static int register_kprobe_event(struct trace_kprobe *tk);
238 static int unregister_kprobe_event(struct trace_kprobe *tk);
239 
240 static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs);
241 static int kretprobe_dispatcher(struct kretprobe_instance *ri,
242                                 struct pt_regs *regs);
243 
244 static void free_trace_kprobe(struct trace_kprobe *tk)
245 {
246         if (tk) {
247                 trace_probe_cleanup(&tk->tp);
248                 kfree(tk->symbol);
249                 free_percpu(tk->nhit);
250                 kfree(tk);
251         }
252 }
253 
254 /*
255  * Allocate new trace_probe and initialize it (including kprobes).
256  */
257 static struct trace_kprobe *alloc_trace_kprobe(const char *group,
258                                              const char *event,
259                                              void *addr,
260                                              const char *symbol,
261                                              unsigned long offs,
262                                              int maxactive,
263                                              int nargs, bool is_return)
264 {
265         struct trace_kprobe *tk;
266         int ret = -ENOMEM;
267 
268         tk = kzalloc(SIZEOF_TRACE_KPROBE(nargs), GFP_KERNEL);
269         if (!tk)
270                 return ERR_PTR(ret);
271 
272         tk->nhit = alloc_percpu(unsigned long);
273         if (!tk->nhit)
274                 goto error;
275 
276         if (symbol) {
277                 tk->symbol = kstrdup(symbol, GFP_KERNEL);
278                 if (!tk->symbol)
279                         goto error;
280                 tk->rp.kp.symbol_name = tk->symbol;
281                 tk->rp.kp.offset = offs;
282         } else
283                 tk->rp.kp.addr = addr;
284 
285         if (is_return)
286                 tk->rp.handler = kretprobe_dispatcher;
287         else
288                 tk->rp.kp.pre_handler = kprobe_dispatcher;
289 
290         tk->rp.maxactive = maxactive;
291         INIT_HLIST_NODE(&tk->rp.kp.hlist);
292         INIT_LIST_HEAD(&tk->rp.kp.list);
293 
294         ret = trace_probe_init(&tk->tp, event, group, false);
295         if (ret < 0)
296                 goto error;
297 
298         dyn_event_init(&tk->devent, &trace_kprobe_ops);
299         return tk;
300 error:
301         free_trace_kprobe(tk);
302         return ERR_PTR(ret);
303 }
304 
305 static struct trace_kprobe *find_trace_kprobe(const char *event,
306                                               const char *group)
307 {
308         struct dyn_event *pos;
309         struct trace_kprobe *tk;
310 
311         for_each_trace_kprobe(tk, pos)
312                 if (strcmp(trace_probe_name(&tk->tp), event) == 0 &&
313                     strcmp(trace_probe_group_name(&tk->tp), group) == 0)
314                         return tk;
315         return NULL;
316 }
317 
318 static inline int __enable_trace_kprobe(struct trace_kprobe *tk)
319 {
320         int ret = 0;
321 
322         if (trace_kprobe_is_registered(tk) && !trace_kprobe_has_gone(tk)) {
323                 if (trace_kprobe_is_return(tk))
324                         ret = enable_kretprobe(&tk->rp);
325                 else
326                         ret = enable_kprobe(&tk->rp.kp);
327         }
328 
329         return ret;
330 }
331 
332 static void __disable_trace_kprobe(struct trace_probe *tp)
333 {
334         struct trace_probe *pos;
335         struct trace_kprobe *tk;
336 
337         list_for_each_entry(pos, trace_probe_probe_list(tp), list) {
338                 tk = container_of(pos, struct trace_kprobe, tp);
339                 if (!trace_kprobe_is_registered(tk))
340                         continue;
341                 if (trace_kprobe_is_return(tk))
342                         disable_kretprobe(&tk->rp);
343                 else
344                         disable_kprobe(&tk->rp.kp);
345         }
346 }
347 
348 /*
349  * Enable trace_probe
350  * if the file is NULL, enable "perf" handler, or enable "trace" handler.
351  */
352 static int enable_trace_kprobe(struct trace_event_call *call,
353                                 struct trace_event_file *file)
354 {
355         struct trace_probe *pos, *tp;
356         struct trace_kprobe *tk;
357         bool enabled;
358         int ret = 0;
359 
360         tp = trace_probe_primary_from_call(call);
361         if (WARN_ON_ONCE(!tp))
362                 return -ENODEV;
363         enabled = trace_probe_is_enabled(tp);
364 
365         /* This also changes "enabled" state */
366         if (file) {
367                 ret = trace_probe_add_file(tp, file);
368                 if (ret)
369                         return ret;
370         } else
371                 trace_probe_set_flag(tp, TP_FLAG_PROFILE);
372 
373         if (enabled)
374                 return 0;
375 
376         list_for_each_entry(pos, trace_probe_probe_list(tp), list) {
377                 tk = container_of(pos, struct trace_kprobe, tp);
378                 if (trace_kprobe_has_gone(tk))
379                         continue;
380                 ret = __enable_trace_kprobe(tk);
381                 if (ret)
382                         break;
383                 enabled = true;
384         }
385 
386         if (ret) {
387                 /* Failed to enable one of them. Roll back all */
388                 if (enabled)
389                         __disable_trace_kprobe(tp);
390                 if (file)
391                         trace_probe_remove_file(tp, file);
392                 else
393                         trace_probe_clear_flag(tp, TP_FLAG_PROFILE);
394         }
395 
396         return ret;
397 }
398 
399 /*
400  * Disable trace_probe
401  * if the file is NULL, disable "perf" handler, or disable "trace" handler.
402  */
403 static int disable_trace_kprobe(struct trace_event_call *call,
404                                 struct trace_event_file *file)
405 {
406         struct trace_probe *tp;
407 
408         tp = trace_probe_primary_from_call(call);
409         if (WARN_ON_ONCE(!tp))
410                 return -ENODEV;
411 
412         if (file) {
413                 if (!trace_probe_get_file_link(tp, file))
414                         return -ENOENT;
415                 if (!trace_probe_has_single_file(tp))
416                         goto out;
417                 trace_probe_clear_flag(tp, TP_FLAG_TRACE);
418         } else
419                 trace_probe_clear_flag(tp, TP_FLAG_PROFILE);
420 
421         if (!trace_probe_is_enabled(tp))
422                 __disable_trace_kprobe(tp);
423 
424  out:
425         if (file)
426                 /*
427                  * Synchronization is done in below function. For perf event,
428                  * file == NULL and perf_trace_event_unreg() calls
429                  * tracepoint_synchronize_unregister() to ensure synchronize
430                  * event. We don't need to care about it.
431                  */
432                 trace_probe_remove_file(tp, file);
433 
434         return 0;
435 }
436 
437 #if defined(CONFIG_DYNAMIC_FTRACE) && \
438         !defined(CONFIG_KPROBE_EVENTS_ON_NOTRACE)
439 static bool __within_notrace_func(unsigned long addr)
440 {
441         unsigned long offset, size;
442 
443         if (!addr || !kallsyms_lookup_size_offset(addr, &size, &offset))
444                 return false;
445 
446         /* Get the entry address of the target function */
447         addr -= offset;
448 
449         /*
450          * Since ftrace_location_range() does inclusive range check, we need
451          * to subtract 1 byte from the end address.
452          */
453         return !ftrace_location_range(addr, addr + size - 1);
454 }
455 
456 static bool within_notrace_func(struct trace_kprobe *tk)
457 {
458         unsigned long addr = trace_kprobe_address(tk);
459         char symname[KSYM_NAME_LEN], *p;
460 
461         if (!__within_notrace_func(addr))
462                 return false;
463 
464         /* Check if the address is on a suffixed-symbol */
465         if (!lookup_symbol_name(addr, symname)) {
466                 p = strchr(symname, '.');
467                 if (!p)
468                         return true;
469                 *p = '\0';
470                 addr = (unsigned long)kprobe_lookup_name(symname, 0);
471                 if (addr)
472                         return __within_notrace_func(addr);
473         }
474 
475         return true;
476 }
477 #else
478 #define within_notrace_func(tk) (false)
479 #endif
480 
481 /* Internal register function - just handle k*probes and flags */
482 static int __register_trace_kprobe(struct trace_kprobe *tk)
483 {
484         int i, ret;
485 
486         ret = security_locked_down(LOCKDOWN_KPROBES);
487         if (ret)
488                 return ret;
489 
490         if (trace_kprobe_is_registered(tk))
491                 return -EINVAL;
492 
493         if (within_notrace_func(tk)) {
494                 pr_warn("Could not probe notrace function %s\n",
495                         trace_kprobe_symbol(tk));
496                 return -EINVAL;
497         }
498 
499         for (i = 0; i < tk->tp.nr_args; i++) {
500                 ret = traceprobe_update_arg(&tk->tp.args[i]);
501                 if (ret)
502                         return ret;
503         }
504 
505         /* Set/clear disabled flag according to tp->flag */
506         if (trace_probe_is_enabled(&tk->tp))
507                 tk->rp.kp.flags &= ~KPROBE_FLAG_DISABLED;
508         else
509                 tk->rp.kp.flags |= KPROBE_FLAG_DISABLED;
510 
511         if (trace_kprobe_is_return(tk))
512                 ret = register_kretprobe(&tk->rp);
513         else
514                 ret = register_kprobe(&tk->rp.kp);
515 
516         return ret;
517 }
518 
519 /* Internal unregister function - just handle k*probes and flags */
520 static void __unregister_trace_kprobe(struct trace_kprobe *tk)
521 {
522         if (trace_kprobe_is_registered(tk)) {
523                 if (trace_kprobe_is_return(tk))
524                         unregister_kretprobe(&tk->rp);
525                 else
526                         unregister_kprobe(&tk->rp.kp);
527                 /* Cleanup kprobe for reuse and mark it unregistered */
528                 INIT_HLIST_NODE(&tk->rp.kp.hlist);
529                 INIT_LIST_HEAD(&tk->rp.kp.list);
530                 if (tk->rp.kp.symbol_name)
531                         tk->rp.kp.addr = NULL;
532         }
533 }
534 
535 /* Unregister a trace_probe and probe_event */
536 static int unregister_trace_kprobe(struct trace_kprobe *tk)
537 {
538         /* If other probes are on the event, just unregister kprobe */
539         if (trace_probe_has_sibling(&tk->tp))
540                 goto unreg;
541 
542         /* Enabled event can not be unregistered */
543         if (trace_probe_is_enabled(&tk->tp))
544                 return -EBUSY;
545 
546         /* Will fail if probe is being used by ftrace or perf */
547         if (unregister_kprobe_event(tk))
548                 return -EBUSY;
549 
550 unreg:
551         __unregister_trace_kprobe(tk);
552         dyn_event_remove(&tk->devent);
553         trace_probe_unlink(&tk->tp);
554 
555         return 0;
556 }
557 
558 static bool trace_kprobe_has_same_kprobe(struct trace_kprobe *orig,
559                                          struct trace_kprobe *comp)
560 {
561         struct trace_probe_event *tpe = orig->tp.event;
562         struct trace_probe *pos;
563         int i;
564 
565         list_for_each_entry(pos, &tpe->probes, list) {
566                 orig = container_of(pos, struct trace_kprobe, tp);
567                 if (strcmp(trace_kprobe_symbol(orig),
568                            trace_kprobe_symbol(comp)) ||
569                     trace_kprobe_offset(orig) != trace_kprobe_offset(comp))
570                         continue;
571 
572                 /*
573                  * trace_probe_compare_arg_type() ensured that nr_args and
574                  * each argument name and type are same. Let's compare comm.
575                  */
576                 for (i = 0; i < orig->tp.nr_args; i++) {
577                         if (strcmp(orig->tp.args[i].comm,
578                                    comp->tp.args[i].comm))
579                                 break;
580                 }
581 
582                 if (i == orig->tp.nr_args)
583                         return true;
584         }
585 
586         return false;
587 }
588 
589 static int append_trace_kprobe(struct trace_kprobe *tk, struct trace_kprobe *to)
590 {
591         int ret;
592 
593         ret = trace_probe_compare_arg_type(&tk->tp, &to->tp);
594         if (ret) {
595                 /* Note that argument starts index = 2 */
596                 trace_probe_log_set_index(ret + 1);
597                 trace_probe_log_err(0, DIFF_ARG_TYPE);
598                 return -EEXIST;
599         }
600         if (trace_kprobe_has_same_kprobe(to, tk)) {
601                 trace_probe_log_set_index(0);
602                 trace_probe_log_err(0, SAME_PROBE);
603                 return -EEXIST;
604         }
605 
606         /* Append to existing event */
607         ret = trace_probe_append(&tk->tp, &to->tp);
608         if (ret)
609                 return ret;
610 
611         /* Register k*probe */
612         ret = __register_trace_kprobe(tk);
613         if (ret == -ENOENT && !trace_kprobe_module_exist(tk)) {
614                 pr_warn("This probe might be able to register after target module is loaded. Continue.\n");
615                 ret = 0;
616         }
617 
618         if (ret)
619                 trace_probe_unlink(&tk->tp);
620         else
621                 dyn_event_add(&tk->devent);
622 
623         return ret;
624 }
625 
626 /* Register a trace_probe and probe_event */
627 static int register_trace_kprobe(struct trace_kprobe *tk)
628 {
629         struct trace_kprobe *old_tk;
630         int ret;
631 
632         mutex_lock(&event_mutex);
633 
634         old_tk = find_trace_kprobe(trace_probe_name(&tk->tp),
635                                    trace_probe_group_name(&tk->tp));
636         if (old_tk) {
637                 if (trace_kprobe_is_return(tk) != trace_kprobe_is_return(old_tk)) {
638                         trace_probe_log_set_index(0);
639                         trace_probe_log_err(0, DIFF_PROBE_TYPE);
640                         ret = -EEXIST;
641                 } else {
642                         ret = append_trace_kprobe(tk, old_tk);
643                 }
644                 goto end;
645         }
646 
647         /* Register new event */
648         ret = register_kprobe_event(tk);
649         if (ret) {
650                 pr_warn("Failed to register probe event(%d)\n", ret);
651                 goto end;
652         }
653 
654         /* Register k*probe */
655         ret = __register_trace_kprobe(tk);
656         if (ret == -ENOENT && !trace_kprobe_module_exist(tk)) {
657                 pr_warn("This probe might be able to register after target module is loaded. Continue.\n");
658                 ret = 0;
659         }
660 
661         if (ret < 0)
662                 unregister_kprobe_event(tk);
663         else
664                 dyn_event_add(&tk->devent);
665 
666 end:
667         mutex_unlock(&event_mutex);
668         return ret;
669 }
670 
671 /* Module notifier call back, checking event on the module */
672 static int trace_kprobe_module_callback(struct notifier_block *nb,
673                                        unsigned long val, void *data)
674 {
675         struct module *mod = data;
676         struct dyn_event *pos;
677         struct trace_kprobe *tk;
678         int ret;
679 
680         if (val != MODULE_STATE_COMING)
681                 return NOTIFY_DONE;
682 
683         /* Update probes on coming module */
684         mutex_lock(&event_mutex);
685         for_each_trace_kprobe(tk, pos) {
686                 if (trace_kprobe_within_module(tk, mod)) {
687                         /* Don't need to check busy - this should have gone. */
688                         __unregister_trace_kprobe(tk);
689                         ret = __register_trace_kprobe(tk);
690                         if (ret)
691                                 pr_warn("Failed to re-register probe %s on %s: %d\n",
692                                         trace_probe_name(&tk->tp),
693                                         module_name(mod), ret);
694                 }
695         }
696         mutex_unlock(&event_mutex);
697 
698         return NOTIFY_DONE;
699 }
700 
701 static struct notifier_block trace_kprobe_module_nb = {
702         .notifier_call = trace_kprobe_module_callback,
703         .priority = 1   /* Invoked after kprobe module callback */
704 };
705 
706 /* Convert certain expected symbols into '_' when generating event names */
707 static inline void sanitize_event_name(char *name)
708 {
709         while (*name++ != '\0')
710                 if (*name == ':' || *name == '.')
711                         *name = '_';
712 }
713 
714 static int __trace_kprobe_create(int argc, const char *argv[])
715 {
716         /*
717          * Argument syntax:
718          *  - Add kprobe:
719          *      p[:[GRP/]EVENT] [MOD:]KSYM[+OFFS]|KADDR [FETCHARGS]
720          *  - Add kretprobe:
721          *      r[MAXACTIVE][:[GRP/]EVENT] [MOD:]KSYM[+0] [FETCHARGS]
722          *    Or
723          *      p:[GRP/]EVENT] [MOD:]KSYM[+0]%return [FETCHARGS]
724          *
725          * Fetch args:
726          *  $retval     : fetch return value
727          *  $stack      : fetch stack address
728          *  $stackN     : fetch Nth of stack (N:0-)
729          *  $comm       : fetch current task comm
730          *  @ADDR       : fetch memory at ADDR (ADDR should be in kernel)
731          *  @SYM[+|-offs] : fetch memory at SYM +|- offs (SYM is a data symbol)
732          *  %REG        : fetch register REG
733          * Dereferencing memory fetch:
734          *  +|-offs(ARG) : fetch memory at ARG +|- offs address.
735          * Alias name of args:
736          *  NAME=FETCHARG : set NAME as alias of FETCHARG.
737          * Type of args:
738          *  FETCHARG:TYPE : use TYPE instead of unsigned long.
739          */
740         struct trace_kprobe *tk = NULL;
741         int i, len, ret = 0;
742         bool is_return = false;
743         char *symbol = NULL, *tmp = NULL;
744         const char *event = NULL, *group = KPROBE_EVENT_SYSTEM;
745         int maxactive = 0;
746         long offset = 0;
747         void *addr = NULL;
748         char buf[MAX_EVENT_NAME_LEN];
749         unsigned int flags = TPARG_FL_KERNEL;
750 
751         switch (argv[0][0]) {
752         case 'r':
753                 is_return = true;
754                 break;
755         case 'p':
756                 break;
757         default:
758                 return -ECANCELED;
759         }
760         if (argc < 2)
761                 return -ECANCELED;
762 
763         trace_probe_log_init("trace_kprobe", argc, argv);
764 
765         event = strchr(&argv[0][1], ':');
766         if (event)
767                 event++;
768 
769         if (isdigit(argv[0][1])) {
770                 if (!is_return) {
771                         trace_probe_log_err(1, MAXACT_NO_KPROBE);
772                         goto parse_error;
773                 }
774                 if (event)
775                         len = event - &argv[0][1] - 1;
776                 else
777                         len = strlen(&argv[0][1]);
778                 if (len > MAX_EVENT_NAME_LEN - 1) {
779                         trace_probe_log_err(1, BAD_MAXACT);
780                         goto parse_error;
781                 }
782                 memcpy(buf, &argv[0][1], len);
783                 buf[len] = '\0';
784                 ret = kstrtouint(buf, 0, &maxactive);
785                 if (ret || !maxactive) {
786                         trace_probe_log_err(1, BAD_MAXACT);
787                         goto parse_error;
788                 }
789                 /* kretprobes instances are iterated over via a list. The
790                  * maximum should stay reasonable.
791                  */
792                 if (maxactive > KRETPROBE_MAXACTIVE_MAX) {
793                         trace_probe_log_err(1, MAXACT_TOO_BIG);
794                         goto parse_error;
795                 }
796         }
797 
798         /* try to parse an address. if that fails, try to read the
799          * input as a symbol. */
800         if (kstrtoul(argv[1], 0, (unsigned long *)&addr)) {
801                 trace_probe_log_set_index(1);
802                 /* Check whether uprobe event specified */
803                 if (strchr(argv[1], '/') && strchr(argv[1], ':')) {
804                         ret = -ECANCELED;
805                         goto error;
806                 }
807                 /* a symbol specified */
808                 symbol = kstrdup(argv[1], GFP_KERNEL);
809                 if (!symbol)
810                         return -ENOMEM;
811 
812                 tmp = strchr(symbol, '%');
813                 if (tmp) {
814                         if (!strcmp(tmp, "%return")) {
815                                 *tmp = '\0';
816                                 is_return = true;
817                         } else {
818                                 trace_probe_log_err(tmp - symbol, BAD_ADDR_SUFFIX);
819                                 goto parse_error;
820                         }
821                 }
822 
823                 /* TODO: support .init module functions */
824                 ret = traceprobe_split_symbol_offset(symbol, &offset);
825                 if (ret || offset < 0 || offset > UINT_MAX) {
826                         trace_probe_log_err(0, BAD_PROBE_ADDR);
827                         goto parse_error;
828                 }
829                 if (is_return)
830                         flags |= TPARG_FL_RETURN;
831                 ret = kprobe_on_func_entry(NULL, symbol, offset);
832                 if (ret == 0)
833                         flags |= TPARG_FL_FENTRY;
834                 /* Defer the ENOENT case until register kprobe */
835                 if (ret == -EINVAL && is_return) {
836                         trace_probe_log_err(0, BAD_RETPROBE);
837                         goto parse_error;
838                 }
839         }
840 
841         trace_probe_log_set_index(0);
842         if (event) {
843                 ret = traceprobe_parse_event_name(&event, &group, buf,
844                                                   event - argv[0]);
845                 if (ret)
846                         goto parse_error;
847         } else {
848                 /* Make a new event name */
849                 if (symbol)
850                         snprintf(buf, MAX_EVENT_NAME_LEN, "%c_%s_%ld",
851                                  is_return ? 'r' : 'p', symbol, offset);
852                 else
853                         snprintf(buf, MAX_EVENT_NAME_LEN, "%c_0x%p",
854                                  is_return ? 'r' : 'p', addr);
855                 sanitize_event_name(buf);
856                 event = buf;
857         }
858 
859         /* setup a probe */
860         tk = alloc_trace_kprobe(group, event, addr, symbol, offset, maxactive,
861                                argc - 2, is_return);
862         if (IS_ERR(tk)) {
863                 ret = PTR_ERR(tk);
864                 /* This must return -ENOMEM, else there is a bug */
865                 WARN_ON_ONCE(ret != -ENOMEM);
866                 goto out;       /* We know tk is not allocated */
867         }
868         argc -= 2; argv += 2;
869 
870         /* parse arguments */
871         for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) {
872                 tmp = kstrdup(argv[i], GFP_KERNEL);
873                 if (!tmp) {
874                         ret = -ENOMEM;
875                         goto error;
876                 }
877 
878                 trace_probe_log_set_index(i + 2);
879                 ret = traceprobe_parse_probe_arg(&tk->tp, i, tmp, flags);
880                 kfree(tmp);
881                 if (ret)
882                         goto error;     /* This can be -ENOMEM */
883         }
884 
885         ret = traceprobe_set_print_fmt(&tk->tp, is_return);
886         if (ret < 0)
887                 goto error;
888 
889         ret = register_trace_kprobe(tk);
890         if (ret) {
891                 trace_probe_log_set_index(1);
892                 if (ret == -EILSEQ)
893                         trace_probe_log_err(0, BAD_INSN_BNDRY);
894                 else if (ret == -ENOENT)
895                         trace_probe_log_err(0, BAD_PROBE_ADDR);
896                 else if (ret != -ENOMEM && ret != -EEXIST)
897                         trace_probe_log_err(0, FAIL_REG_PROBE);
898                 goto error;
899         }
900 
901 out:
902         trace_probe_log_clear();
903         kfree(symbol);
904         return ret;
905 
906 parse_error:
907         ret = -EINVAL;
908 error:
909         free_trace_kprobe(tk);
910         goto out;
911 }
912 
913 static int trace_kprobe_create(const char *raw_command)
914 {
915         return trace_probe_create(raw_command, __trace_kprobe_create);
916 }
917 
918 static int create_or_delete_trace_kprobe(const char *raw_command)
919 {
920         int ret;
921 
922         if (raw_command[0] == '-')
923                 return dyn_event_release(raw_command, &trace_kprobe_ops);
924 
925         ret = trace_kprobe_create(raw_command);
926         return ret == -ECANCELED ? -EINVAL : ret;
927 }
928 
929 static int trace_kprobe_run_command(struct dynevent_cmd *cmd)
930 {
931         return create_or_delete_trace_kprobe(cmd->seq.buffer);
932 }
933 
934 /**
935  * kprobe_event_cmd_init - Initialize a kprobe event command object
936  * @cmd: A pointer to the dynevent_cmd struct representing the new event
937  * @buf: A pointer to the buffer used to build the command
938  * @maxlen: The length of the buffer passed in @buf
939  *
940  * Initialize a synthetic event command object.  Use this before
941  * calling any of the other kprobe_event functions.
942  */
943 void kprobe_event_cmd_init(struct dynevent_cmd *cmd, char *buf, int maxlen)
944 {
945         dynevent_cmd_init(cmd, buf, maxlen, DYNEVENT_TYPE_KPROBE,
946                           trace_kprobe_run_command);
947 }
948 EXPORT_SYMBOL_GPL(kprobe_event_cmd_init);
949 
950 /**
951  * __kprobe_event_gen_cmd_start - Generate a kprobe event command from arg list
952  * @cmd: A pointer to the dynevent_cmd struct representing the new event
953  * @name: The name of the kprobe event
954  * @loc: The location of the kprobe event
955  * @kretprobe: Is this a return probe?
956  * @args: Variable number of arg (pairs), one pair for each field
957  *
958  * NOTE: Users normally won't want to call this function directly, but
959  * rather use the kprobe_event_gen_cmd_start() wrapper, which automatically
960  * adds a NULL to the end of the arg list.  If this function is used
961  * directly, make sure the last arg in the variable arg list is NULL.
962  *
963  * Generate a kprobe event command to be executed by
964  * kprobe_event_gen_cmd_end().  This function can be used to generate the
965  * complete command or only the first part of it; in the latter case,
966  * kprobe_event_add_fields() can be used to add more fields following this.
967  *
968  * Unlikely the synth_event_gen_cmd_start(), @loc must be specified. This
969  * returns -EINVAL if @loc == NULL.
970  *
971  * Return: 0 if successful, error otherwise.
972  */
973 int __kprobe_event_gen_cmd_start(struct dynevent_cmd *cmd, bool kretprobe,
974                                  const char *name, const char *loc, ...)
975 {
976         char buf[MAX_EVENT_NAME_LEN];
977         struct dynevent_arg arg;
978         va_list args;
979         int ret;
980 
981         if (cmd->type != DYNEVENT_TYPE_KPROBE)
982                 return -EINVAL;
983 
984         if (!loc)
985                 return -EINVAL;
986 
987         if (kretprobe)
988                 snprintf(buf, MAX_EVENT_NAME_LEN, "r:kprobes/%s", name);
989         else
990                 snprintf(buf, MAX_EVENT_NAME_LEN, "p:kprobes/%s", name);
991 
992         ret = dynevent_str_add(cmd, buf);
993         if (ret)
994                 return ret;
995 
996         dynevent_arg_init(&arg, 0);
997         arg.str = loc;
998         ret = dynevent_arg_add(cmd, &arg, NULL);
999         if (ret)
1000                 return ret;
1001 
1002         va_start(args, loc);
1003         for (;;) {
1004                 const char *field;
1005 
1006                 field = va_arg(args, const char *);
1007                 if (!field)
1008                         break;
1009 
1010                 if (++cmd->n_fields > MAX_TRACE_ARGS) {
1011                         ret = -EINVAL;
1012                         break;
1013                 }
1014 
1015                 arg.str = field;
1016                 ret = dynevent_arg_add(cmd, &arg, NULL);
1017                 if (ret)
1018                         break;
1019         }
1020         va_end(args);
1021 
1022         return ret;
1023 }
1024 EXPORT_SYMBOL_GPL(__kprobe_event_gen_cmd_start);
1025 
1026 /**
1027  * __kprobe_event_add_fields - Add probe fields to a kprobe command from arg list
1028  * @cmd: A pointer to the dynevent_cmd struct representing the new event
1029  * @args: Variable number of arg (pairs), one pair for each field
1030  *
1031  * NOTE: Users normally won't want to call this function directly, but
1032  * rather use the kprobe_event_add_fields() wrapper, which
1033  * automatically adds a NULL to the end of the arg list.  If this
1034  * function is used directly, make sure the last arg in the variable
1035  * arg list is NULL.
1036  *
1037  * Add probe fields to an existing kprobe command using a variable
1038  * list of args.  Fields are added in the same order they're listed.
1039  *
1040  * Return: 0 if successful, error otherwise.
1041  */
1042 int __kprobe_event_add_fields(struct dynevent_cmd *cmd, ...)
1043 {
1044         struct dynevent_arg arg;
1045         va_list args;
1046         int ret = 0;
1047 
1048         if (cmd->type != DYNEVENT_TYPE_KPROBE)
1049                 return -EINVAL;
1050 
1051         dynevent_arg_init(&arg, 0);
1052 
1053         va_start(args, cmd);
1054         for (;;) {
1055                 const char *field;
1056 
1057                 field = va_arg(args, const char *);
1058                 if (!field)
1059                         break;
1060 
1061                 if (++cmd->n_fields > MAX_TRACE_ARGS) {
1062                         ret = -EINVAL;
1063                         break;
1064                 }
1065 
1066                 arg.str = field;
1067                 ret = dynevent_arg_add(cmd, &arg, NULL);
1068                 if (ret)
1069                         break;
1070         }
1071         va_end(args);
1072 
1073         return ret;
1074 }
1075 EXPORT_SYMBOL_GPL(__kprobe_event_add_fields);
1076 
1077 /**
1078  * kprobe_event_delete - Delete a kprobe event
1079  * @name: The name of the kprobe event to delete
1080  *
1081  * Delete a kprobe event with the give @name from kernel code rather
1082  * than directly from the command line.
1083  *
1084  * Return: 0 if successful, error otherwise.
1085  */
1086 int kprobe_event_delete(const char *name)
1087 {
1088         char buf[MAX_EVENT_NAME_LEN];
1089 
1090         snprintf(buf, MAX_EVENT_NAME_LEN, "-:%s", name);
1091 
1092         return create_or_delete_trace_kprobe(buf);
1093 }
1094 EXPORT_SYMBOL_GPL(kprobe_event_delete);
1095 
1096 static int trace_kprobe_release(struct dyn_event *ev)
1097 {
1098         struct trace_kprobe *tk = to_trace_kprobe(ev);
1099         int ret = unregister_trace_kprobe(tk);
1100 
1101         if (!ret)
1102                 free_trace_kprobe(tk);
1103         return ret;
1104 }
1105 
1106 static int trace_kprobe_show(struct seq_file *m, struct dyn_event *ev)
1107 {
1108         struct trace_kprobe *tk = to_trace_kprobe(ev);
1109         int i;
1110 
1111         seq_putc(m, trace_kprobe_is_return(tk) ? 'r' : 'p');
1112         if (trace_kprobe_is_return(tk) && tk->rp.maxactive)
1113                 seq_printf(m, "%d", tk->rp.maxactive);
1114         seq_printf(m, ":%s/%s", trace_probe_group_name(&tk->tp),
1115                                 trace_probe_name(&tk->tp));
1116 
1117         if (!tk->symbol)
1118                 seq_printf(m, " 0x%p", tk->rp.kp.addr);
1119         else if (tk->rp.kp.offset)
1120                 seq_printf(m, " %s+%u", trace_kprobe_symbol(tk),
1121                            tk->rp.kp.offset);
1122         else
1123                 seq_printf(m, " %s", trace_kprobe_symbol(tk));
1124 
1125         for (i = 0; i < tk->tp.nr_args; i++)
1126                 seq_printf(m, " %s=%s", tk->tp.args[i].name, tk->tp.args[i].comm);
1127         seq_putc(m, '\n');
1128 
1129         return 0;
1130 }
1131 
1132 static int probes_seq_show(struct seq_file *m, void *v)
1133 {
1134         struct dyn_event *ev = v;
1135 
1136         if (!is_trace_kprobe(ev))
1137                 return 0;
1138 
1139         return trace_kprobe_show(m, ev);
1140 }
1141 
1142 static const struct seq_operations probes_seq_op = {
1143         .start  = dyn_event_seq_start,
1144         .next   = dyn_event_seq_next,
1145         .stop   = dyn_event_seq_stop,
1146         .show   = probes_seq_show
1147 };
1148 
1149 static int probes_open(struct inode *inode, struct file *file)
1150 {
1151         int ret;
1152 
1153         ret = security_locked_down(LOCKDOWN_TRACEFS);
1154         if (ret)
1155                 return ret;
1156 
1157         if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) {
1158                 ret = dyn_events_release_all(&trace_kprobe_ops);
1159                 if (ret < 0)
1160                         return ret;
1161         }
1162 
1163         return seq_open(file, &probes_seq_op);
1164 }
1165 
1166 static ssize_t probes_write(struct file *file, const char __user *buffer,
1167                             size_t count, loff_t *ppos)
1168 {
1169         return trace_parse_run_command(file, buffer, count, ppos,
1170                                        create_or_delete_trace_kprobe);
1171 }
1172 
1173 static const struct file_operations kprobe_events_ops = {
1174         .owner          = THIS_MODULE,
1175         .open           = probes_open,
1176         .read           = seq_read,
1177         .llseek         = seq_lseek,
1178         .release        = seq_release,
1179         .write          = probes_write,
1180 };
1181 
1182 /* Probes profiling interfaces */
1183 static int probes_profile_seq_show(struct seq_file *m, void *v)
1184 {
1185         struct dyn_event *ev = v;
1186         struct trace_kprobe *tk;
1187 
1188         if (!is_trace_kprobe(ev))
1189                 return 0;
1190 
1191         tk = to_trace_kprobe(ev);
1192         seq_printf(m, "  %-44s %15lu %15lu\n",
1193                    trace_probe_name(&tk->tp),
1194                    trace_kprobe_nhit(tk),
1195                    tk->rp.kp.nmissed);
1196 
1197         return 0;
1198 }
1199 
1200 static const struct seq_operations profile_seq_op = {
1201         .start  = dyn_event_seq_start,
1202         .next   = dyn_event_seq_next,
1203         .stop   = dyn_event_seq_stop,
1204         .show   = probes_profile_seq_show
1205 };
1206 
1207 static int profile_open(struct inode *inode, struct file *file)
1208 {
1209         int ret;
1210 
1211         ret = security_locked_down(LOCKDOWN_TRACEFS);
1212         if (ret)
1213                 return ret;
1214 
1215         return seq_open(file, &profile_seq_op);
1216 }
1217 
1218 static const struct file_operations kprobe_profile_ops = {
1219         .owner          = THIS_MODULE,
1220         .open           = profile_open,
1221         .read           = seq_read,
1222         .llseek         = seq_lseek,
1223         .release        = seq_release,
1224 };
1225 
1226 /* Kprobe specific fetch functions */
1227 
1228 /* Return the length of string -- including null terminal byte */
1229 static nokprobe_inline int
1230 fetch_store_strlen_user(unsigned long addr)
1231 {
1232         const void __user *uaddr =  (__force const void __user *)addr;
1233 
1234         return strnlen_user_nofault(uaddr, MAX_STRING_SIZE);
1235 }
1236 
1237 /* Return the length of string -- including null terminal byte */
1238 static nokprobe_inline int
1239 fetch_store_strlen(unsigned long addr)
1240 {
1241         int ret, len = 0;
1242         u8 c;
1243 
1244 #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
1245         if (addr < TASK_SIZE)
1246                 return fetch_store_strlen_user(addr);
1247 #endif
1248 
1249         do {
1250                 ret = copy_from_kernel_nofault(&c, (u8 *)addr + len, 1);
1251                 len++;
1252         } while (c && ret == 0 && len < MAX_STRING_SIZE);
1253 
1254         return (ret < 0) ? ret : len;
1255 }
1256 
1257 /*
1258  * Fetch a null-terminated string from user. Caller MUST set *(u32 *)buf
1259  * with max length and relative data location.
1260  */
1261 static nokprobe_inline int
1262 fetch_store_string_user(unsigned long addr, void *dest, void *base)
1263 {
1264         const void __user *uaddr =  (__force const void __user *)addr;
1265         int maxlen = get_loc_len(*(u32 *)dest);
1266         void *__dest;
1267         long ret;
1268 
1269         if (unlikely(!maxlen))
1270                 return -ENOMEM;
1271 
1272         __dest = get_loc_data(dest, base);
1273 
1274         ret = strncpy_from_user_nofault(__dest, uaddr, maxlen);
1275         if (ret >= 0)
1276                 *(u32 *)dest = make_data_loc(ret, __dest - base);
1277 
1278         return ret;
1279 }
1280 
1281 /*
1282  * Fetch a null-terminated string. Caller MUST set *(u32 *)buf with max
1283  * length and relative data location.
1284  */
1285 static nokprobe_inline int
1286 fetch_store_string(unsigned long addr, void *dest, void *base)
1287 {
1288         int maxlen = get_loc_len(*(u32 *)dest);
1289         void *__dest;
1290         long ret;
1291 
1292 #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
1293         if ((unsigned long)addr < TASK_SIZE)
1294                 return fetch_store_string_user(addr, dest, base);
1295 #endif
1296 
1297         if (unlikely(!maxlen))
1298                 return -ENOMEM;
1299 
1300         __dest = get_loc_data(dest, base);
1301 
1302         /*
1303          * Try to get string again, since the string can be changed while
1304          * probing.
1305          */
1306         ret = strncpy_from_kernel_nofault(__dest, (void *)addr, maxlen);
1307         if (ret >= 0)
1308                 *(u32 *)dest = make_data_loc(ret, __dest - base);
1309 
1310         return ret;
1311 }
1312 
1313 static nokprobe_inline int
1314 probe_mem_read_user(void *dest, void *src, size_t size)
1315 {
1316         const void __user *uaddr =  (__force const void __user *)src;
1317 
1318         return copy_from_user_nofault(dest, uaddr, size);
1319 }
1320 
1321 static nokprobe_inline int
1322 probe_mem_read(void *dest, void *src, size_t size)
1323 {
1324 #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
1325         if ((unsigned long)src < TASK_SIZE)
1326                 return probe_mem_read_user(dest, src, size);
1327 #endif
1328         return copy_from_kernel_nofault(dest, src, size);
1329 }
1330 
1331 /* Note that we don't verify it, since the code does not come from user space */
1332 static int
1333 process_fetch_insn(struct fetch_insn *code, struct pt_regs *regs, void *dest,
1334                    void *base)
1335 {
1336         unsigned long val;
1337 
1338 retry:
1339         /* 1st stage: get value from context */
1340         switch (code->op) {
1341         case FETCH_OP_REG:
1342                 val = regs_get_register(regs, code->param);
1343                 break;
1344         case FETCH_OP_STACK:
1345                 val = regs_get_kernel_stack_nth(regs, code->param);
1346                 break;
1347         case FETCH_OP_STACKP:
1348                 val = kernel_stack_pointer(regs);
1349                 break;
1350         case FETCH_OP_RETVAL:
1351                 val = regs_return_value(regs);
1352                 break;
1353         case FETCH_OP_IMM:
1354                 val = code->immediate;
1355                 break;
1356         case FETCH_OP_COMM:
1357                 val = (unsigned long)current->comm;
1358                 break;
1359         case FETCH_OP_DATA:
1360                 val = (unsigned long)code->data;
1361                 break;
1362 #ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API
1363         case FETCH_OP_ARG:
1364                 val = regs_get_kernel_argument(regs, code->param);
1365                 break;
1366 #endif
1367         case FETCH_NOP_SYMBOL:  /* Ignore a place holder */
1368                 code++;
1369                 goto retry;
1370         default:
1371                 return -EILSEQ;
1372         }
1373         code++;
1374 
1375         return process_fetch_insn_bottom(code, val, dest, base);
1376 }
1377 NOKPROBE_SYMBOL(process_fetch_insn)
1378 
1379 /* Kprobe handler */
1380 static nokprobe_inline void
1381 __kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs,
1382                     struct trace_event_file *trace_file)
1383 {
1384         struct kprobe_trace_entry_head *entry;
1385         struct trace_event_call *call = trace_probe_event_call(&tk->tp);
1386         struct trace_event_buffer fbuffer;
1387         int dsize;
1388 
1389         WARN_ON(call != trace_file->event_call);
1390 
1391         if (trace_trigger_soft_disabled(trace_file))
1392                 return;
1393 
1394         fbuffer.trace_ctx = tracing_gen_ctx();
1395         fbuffer.trace_file = trace_file;
1396 
1397         dsize = __get_data_size(&tk->tp, regs);
1398 
1399         fbuffer.event =
1400                 trace_event_buffer_lock_reserve(&fbuffer.buffer, trace_file,
1401                                         call->event.type,
1402                                         sizeof(*entry) + tk->tp.size + dsize,
1403                                         fbuffer.trace_ctx);
1404         if (!fbuffer.event)
1405                 return;
1406 
1407         fbuffer.regs = regs;
1408         entry = fbuffer.entry = ring_buffer_event_data(fbuffer.event);
1409         entry->ip = (unsigned long)tk->rp.kp.addr;
1410         store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize);
1411 
1412         trace_event_buffer_commit(&fbuffer);
1413 }
1414 
1415 static void
1416 kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs)
1417 {
1418         struct event_file_link *link;
1419 
1420         trace_probe_for_each_link_rcu(link, &tk->tp)
1421                 __kprobe_trace_func(tk, regs, link->file);
1422 }
1423 NOKPROBE_SYMBOL(kprobe_trace_func);
1424 
1425 /* Kretprobe handler */
1426 static nokprobe_inline void
1427 __kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri,
1428                        struct pt_regs *regs,
1429                        struct trace_event_file *trace_file)
1430 {
1431         struct kretprobe_trace_entry_head *entry;
1432         struct trace_event_buffer fbuffer;
1433         struct trace_event_call *call = trace_probe_event_call(&tk->tp);
1434         int dsize;
1435 
1436         WARN_ON(call != trace_file->event_call);
1437 
1438         if (trace_trigger_soft_disabled(trace_file))
1439                 return;
1440 
1441         fbuffer.trace_ctx = tracing_gen_ctx();
1442         fbuffer.trace_file = trace_file;
1443 
1444         dsize = __get_data_size(&tk->tp, regs);
1445         fbuffer.event =
1446                 trace_event_buffer_lock_reserve(&fbuffer.buffer, trace_file,
1447                                         call->event.type,
1448                                         sizeof(*entry) + tk->tp.size + dsize,
1449                                         fbuffer.trace_ctx);
1450         if (!fbuffer.event)
1451                 return;
1452 
1453         fbuffer.regs = regs;
1454         entry = fbuffer.entry = ring_buffer_event_data(fbuffer.event);
1455         entry->func = (unsigned long)tk->rp.kp.addr;
1456         entry->ret_ip = (unsigned long)ri->ret_addr;
1457         store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize);
1458 
1459         trace_event_buffer_commit(&fbuffer);
1460 }
1461 
1462 static void
1463 kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri,
1464                      struct pt_regs *regs)
1465 {
1466         struct event_file_link *link;
1467 
1468         trace_probe_for_each_link_rcu(link, &tk->tp)
1469                 __kretprobe_trace_func(tk, ri, regs, link->file);
1470 }
1471 NOKPROBE_SYMBOL(kretprobe_trace_func);
1472 
1473 /* Event entry printers */
1474 static enum print_line_t
1475 print_kprobe_event(struct trace_iterator *iter, int flags,
1476                    struct trace_event *event)
1477 {
1478         struct kprobe_trace_entry_head *field;
1479         struct trace_seq *s = &iter->seq;
1480         struct trace_probe *tp;
1481 
1482         field = (struct kprobe_trace_entry_head *)iter->ent;
1483         tp = trace_probe_primary_from_call(
1484                 container_of(event, struct trace_event_call, event));
1485         if (WARN_ON_ONCE(!tp))
1486                 goto out;
1487 
1488         trace_seq_printf(s, "%s: (", trace_probe_name(tp));
1489 
1490         if (!seq_print_ip_sym(s, field->ip, flags | TRACE_ITER_SYM_OFFSET))
1491                 goto out;
1492 
1493         trace_seq_putc(s, ')');
1494 
1495         if (print_probe_args(s, tp->args, tp->nr_args,
1496                              (u8 *)&field[1], field) < 0)
1497                 goto out;
1498 
1499         trace_seq_putc(s, '\n');
1500  out:
1501         return trace_handle_return(s);
1502 }
1503 
1504 static enum print_line_t
1505 print_kretprobe_event(struct trace_iterator *iter, int flags,
1506                       struct trace_event *event)
1507 {
1508         struct kretprobe_trace_entry_head *field;
1509         struct trace_seq *s = &iter->seq;
1510         struct trace_probe *tp;
1511 
1512         field = (struct kretprobe_trace_entry_head *)iter->ent;
1513         tp = trace_probe_primary_from_call(
1514                 container_of(event, struct trace_event_call, event));
1515         if (WARN_ON_ONCE(!tp))
1516                 goto out;
1517 
1518         trace_seq_printf(s, "%s: (", trace_probe_name(tp));
1519 
1520         if (!seq_print_ip_sym(s, field->ret_ip, flags | TRACE_ITER_SYM_OFFSET))
1521                 goto out;
1522 
1523         trace_seq_puts(s, " <- ");
1524 
1525         if (!seq_print_ip_sym(s, field->func, flags & ~TRACE_ITER_SYM_OFFSET))
1526                 goto out;
1527 
1528         trace_seq_putc(s, ')');
1529 
1530         if (print_probe_args(s, tp->args, tp->nr_args,
1531                              (u8 *)&field[1], field) < 0)
1532                 goto out;
1533 
1534         trace_seq_putc(s, '\n');
1535 
1536  out:
1537         return trace_handle_return(s);
1538 }
1539 
1540 
1541 static int kprobe_event_define_fields(struct trace_event_call *event_call)
1542 {
1543         int ret;
1544         struct kprobe_trace_entry_head field;
1545         struct trace_probe *tp;
1546 
1547         tp = trace_probe_primary_from_call(event_call);
1548         if (WARN_ON_ONCE(!tp))
1549                 return -ENOENT;
1550 
1551         DEFINE_FIELD(unsigned long, ip, FIELD_STRING_IP, 0);
1552 
1553         return traceprobe_define_arg_fields(event_call, sizeof(field), tp);
1554 }
1555 
1556 static int kretprobe_event_define_fields(struct trace_event_call *event_call)
1557 {
1558         int ret;
1559         struct kretprobe_trace_entry_head field;
1560         struct trace_probe *tp;
1561 
1562         tp = trace_probe_primary_from_call(event_call);
1563         if (WARN_ON_ONCE(!tp))
1564                 return -ENOENT;
1565 
1566         DEFINE_FIELD(unsigned long, func, FIELD_STRING_FUNC, 0);
1567         DEFINE_FIELD(unsigned long, ret_ip, FIELD_STRING_RETIP, 0);
1568 
1569         return traceprobe_define_arg_fields(event_call, sizeof(field), tp);
1570 }
1571 
1572 #ifdef CONFIG_PERF_EVENTS
1573 
1574 /* Kprobe profile handler */
1575 static int
1576 kprobe_perf_func(struct trace_kprobe *tk, struct pt_regs *regs)
1577 {
1578         struct trace_event_call *call = trace_probe_event_call(&tk->tp);
1579         struct kprobe_trace_entry_head *entry;
1580         struct hlist_head *head;
1581         int size, __size, dsize;
1582         int rctx;
1583 
1584         if (bpf_prog_array_valid(call)) {
1585                 unsigned long orig_ip = instruction_pointer(regs);
1586                 int ret;
1587 
1588                 ret = trace_call_bpf(call, regs);
1589 
1590                 /*
1591                  * We need to check and see if we modified the pc of the
1592                  * pt_regs, and if so return 1 so that we don't do the
1593                  * single stepping.
1594                  */
1595                 if (orig_ip != instruction_pointer(regs))
1596                         return 1;
1597                 if (!ret)
1598                         return 0;
1599         }
1600 
1601         head = this_cpu_ptr(call->perf_events);
1602         if (hlist_empty(head))
1603                 return 0;
1604 
1605         dsize = __get_data_size(&tk->tp, regs);
1606         __size = sizeof(*entry) + tk->tp.size + dsize;
1607         size = ALIGN(__size + sizeof(u32), sizeof(u64));
1608         size -= sizeof(u32);
1609 
1610         entry = perf_trace_buf_alloc(size, NULL, &rctx);
1611         if (!entry)
1612                 return 0;
1613 
1614         entry->ip = (unsigned long)tk->rp.kp.addr;
1615         memset(&entry[1], 0, dsize);
1616         store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize);
1617         perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs,
1618                               head, NULL);
1619         return 0;
1620 }
1621 NOKPROBE_SYMBOL(kprobe_perf_func);
1622 
1623 /* Kretprobe profile handler */
1624 static void
1625 kretprobe_perf_func(struct trace_kprobe *tk, struct kretprobe_instance *ri,
1626                     struct pt_regs *regs)
1627 {
1628         struct trace_event_call *call = trace_probe_event_call(&tk->tp);
1629         struct kretprobe_trace_entry_head *entry;
1630         struct hlist_head *head;
1631         int size, __size, dsize;
1632         int rctx;
1633 
1634         if (bpf_prog_array_valid(call) && !trace_call_bpf(call, regs))
1635                 return;
1636 
1637         head = this_cpu_ptr(call->perf_events);
1638         if (hlist_empty(head))
1639                 return;
1640 
1641         dsize = __get_data_size(&tk->tp, regs);
1642         __size = sizeof(*entry) + tk->tp.size + dsize;
1643         size = ALIGN(__size + sizeof(u32), sizeof(u64));
1644         size -= sizeof(u32);
1645 
1646         entry = perf_trace_buf_alloc(size, NULL, &rctx);
1647         if (!entry)
1648                 return;
1649 
1650         entry->func = (unsigned long)tk->rp.kp.addr;
1651         entry->ret_ip = (unsigned long)ri->ret_addr;
1652         store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize);
1653         perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs,
1654                               head, NULL);
1655 }
1656 NOKPROBE_SYMBOL(kretprobe_perf_func);
1657 
1658 int bpf_get_kprobe_info(const struct perf_event *event, u32 *fd_type,
1659                         const char **symbol, u64 *probe_offset,
1660                         u64 *probe_addr, bool perf_type_tracepoint)
1661 {
1662         const char *pevent = trace_event_name(event->tp_event);
1663         const char *group = event->tp_event->class->system;
1664         struct trace_kprobe *tk;
1665 
1666         if (perf_type_tracepoint)
1667                 tk = find_trace_kprobe(pevent, group);
1668         else
1669                 tk = trace_kprobe_primary_from_call(event->tp_event);
1670         if (!tk)
1671                 return -EINVAL;
1672 
1673         *fd_type = trace_kprobe_is_return(tk) ? BPF_FD_TYPE_KRETPROBE
1674                                               : BPF_FD_TYPE_KPROBE;
1675         if (tk->symbol) {
1676                 *symbol = tk->symbol;
1677                 *probe_offset = tk->rp.kp.offset;
1678                 *probe_addr = 0;
1679         } else {
1680                 *symbol = NULL;
1681                 *probe_offset = 0;
1682                 *probe_addr = (unsigned long)tk->rp.kp.addr;
1683         }
1684         return 0;
1685 }
1686 #endif  /* CONFIG_PERF_EVENTS */
1687 
1688 /*
1689  * called by perf_trace_init() or __ftrace_set_clr_event() under event_mutex.
1690  *
1691  * kprobe_trace_self_tests_init() does enable_trace_probe/disable_trace_probe
1692  * lockless, but we can't race with this __init function.
1693  */
1694 static int kprobe_register(struct trace_event_call *event,
1695                            enum trace_reg type, void *data)
1696 {
1697         struct trace_event_file *file = data;
1698 
1699         switch (type) {
1700         case TRACE_REG_REGISTER:
1701                 return enable_trace_kprobe(event, file);
1702         case TRACE_REG_UNREGISTER:
1703                 return disable_trace_kprobe(event, file);
1704 
1705 #ifdef CONFIG_PERF_EVENTS
1706         case TRACE_REG_PERF_REGISTER:
1707                 return enable_trace_kprobe(event, NULL);
1708         case TRACE_REG_PERF_UNREGISTER:
1709                 return disable_trace_kprobe(event, NULL);
1710         case TRACE_REG_PERF_OPEN:
1711         case TRACE_REG_PERF_CLOSE:
1712         case TRACE_REG_PERF_ADD:
1713         case TRACE_REG_PERF_DEL:
1714                 return 0;
1715 #endif
1716         }
1717         return 0;
1718 }
1719 
1720 static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs)
1721 {
1722         struct trace_kprobe *tk = container_of(kp, struct trace_kprobe, rp.kp);
1723         int ret = 0;
1724 
1725         raw_cpu_inc(*tk->nhit);
1726 
1727         if (trace_probe_test_flag(&tk->tp, TP_FLAG_TRACE))
1728                 kprobe_trace_func(tk, regs);
1729 #ifdef CONFIG_PERF_EVENTS
1730         if (trace_probe_test_flag(&tk->tp, TP_FLAG_PROFILE))
1731                 ret = kprobe_perf_func(tk, regs);
1732 #endif
1733         return ret;
1734 }
1735 NOKPROBE_SYMBOL(kprobe_dispatcher);
1736 
1737 static int
1738 kretprobe_dispatcher(struct kretprobe_instance *ri, struct pt_regs *regs)
1739 {
1740         struct kretprobe *rp = get_kretprobe(ri);
1741         struct trace_kprobe *tk = container_of(rp, struct trace_kprobe, rp);
1742 
1743         raw_cpu_inc(*tk->nhit);
1744 
1745         if (trace_probe_test_flag(&tk->tp, TP_FLAG_TRACE))
1746                 kretprobe_trace_func(tk, ri, regs);
1747 #ifdef CONFIG_PERF_EVENTS
1748         if (trace_probe_test_flag(&tk->tp, TP_FLAG_PROFILE))
1749                 kretprobe_perf_func(tk, ri, regs);
1750 #endif
1751         return 0;       /* We don't tweak kernel, so just return 0 */
1752 }
1753 NOKPROBE_SYMBOL(kretprobe_dispatcher);
1754 
1755 static struct trace_event_functions kretprobe_funcs = {
1756         .trace          = print_kretprobe_event
1757 };
1758 
1759 static struct trace_event_functions kprobe_funcs = {
1760         .trace          = print_kprobe_event
1761 };
1762 
1763 static struct trace_event_fields kretprobe_fields_array[] = {
1764         { .type = TRACE_FUNCTION_TYPE,
1765           .define_fields = kretprobe_event_define_fields },
1766         {}
1767 };
1768 
1769 static struct trace_event_fields kprobe_fields_array[] = {
1770         { .type = TRACE_FUNCTION_TYPE,
1771           .define_fields = kprobe_event_define_fields },
1772         {}
1773 };
1774 
1775 static inline void init_trace_event_call(struct trace_kprobe *tk)
1776 {
1777         struct trace_event_call *call = trace_probe_event_call(&tk->tp);
1778 
1779         if (trace_kprobe_is_return(tk)) {
1780                 call->event.funcs = &kretprobe_funcs;
1781                 call->class->fields_array = kretprobe_fields_array;
1782         } else {
1783                 call->event.funcs = &kprobe_funcs;
1784                 call->class->fields_array = kprobe_fields_array;
1785         }
1786 
1787         call->flags = TRACE_EVENT_FL_KPROBE;
1788         call->class->reg = kprobe_register;
1789 }
1790 
1791 static int register_kprobe_event(struct trace_kprobe *tk)
1792 {
1793         init_trace_event_call(tk);
1794 
1795         return trace_probe_register_event_call(&tk->tp);
1796 }
1797 
1798 static int unregister_kprobe_event(struct trace_kprobe *tk)
1799 {
1800         return trace_probe_unregister_event_call(&tk->tp);
1801 }
1802 
1803 #ifdef CONFIG_PERF_EVENTS
1804 /* create a trace_kprobe, but don't add it to global lists */
1805 struct trace_event_call *
1806 create_local_trace_kprobe(char *func, void *addr, unsigned long offs,
1807                           bool is_return)
1808 {
1809         struct trace_kprobe *tk;
1810         int ret;
1811         char *event;
1812 
1813         /*
1814          * local trace_kprobes are not added to dyn_event, so they are never
1815          * searched in find_trace_kprobe(). Therefore, there is no concern of
1816          * duplicated name here.
1817          */
1818         event = func ? func : "DUMMY_EVENT";
1819 
1820         tk = alloc_trace_kprobe(KPROBE_EVENT_SYSTEM, event, (void *)addr, func,
1821                                 offs, 0 /* maxactive */, 0 /* nargs */,
1822                                 is_return);
1823 
1824         if (IS_ERR(tk)) {
1825                 pr_info("Failed to allocate trace_probe.(%d)\n",
1826                         (int)PTR_ERR(tk));
1827                 return ERR_CAST(tk);
1828         }
1829 
1830         init_trace_event_call(tk);
1831 
1832         if (traceprobe_set_print_fmt(&tk->tp, trace_kprobe_is_return(tk)) < 0) {
1833                 ret = -ENOMEM;
1834                 goto error;
1835         }
1836 
1837         ret = __register_trace_kprobe(tk);
1838         if (ret < 0)
1839                 goto error;
1840 
1841         return trace_probe_event_call(&tk->tp);
1842 error:
1843         free_trace_kprobe(tk);
1844         return ERR_PTR(ret);
1845 }
1846 
1847 void destroy_local_trace_kprobe(struct trace_event_call *event_call)
1848 {
1849         struct trace_kprobe *tk;
1850 
1851         tk = trace_kprobe_primary_from_call(event_call);
1852         if (unlikely(!tk))
1853                 return;
1854 
1855         if (trace_probe_is_enabled(&tk->tp)) {
1856                 WARN_ON(1);
1857                 return;
1858         }
1859 
1860         __unregister_trace_kprobe(tk);
1861 
1862         free_trace_kprobe(tk);
1863 }
1864 #endif /* CONFIG_PERF_EVENTS */
1865 
1866 static __init void enable_boot_kprobe_events(void)
1867 {
1868         struct trace_array *tr = top_trace_array();
1869         struct trace_event_file *file;
1870         struct trace_kprobe *tk;
1871         struct dyn_event *pos;
1872 
1873         mutex_lock(&event_mutex);
1874         for_each_trace_kprobe(tk, pos) {
1875                 list_for_each_entry(file, &tr->events, list)
1876                         if (file->event_call == trace_probe_event_call(&tk->tp))
1877                                 trace_event_enable_disable(file, 1, 0);
1878         }
1879         mutex_unlock(&event_mutex);
1880 }
1881 
1882 static __init void setup_boot_kprobe_events(void)
1883 {
1884         char *p, *cmd = kprobe_boot_events_buf;
1885         int ret;
1886 
1887         strreplace(kprobe_boot_events_buf, ',', ' ');
1888 
1889         while (cmd && *cmd != '\0') {
1890                 p = strchr(cmd, ';');
1891                 if (p)
1892                         *p++ = '\0';
1893 
1894                 ret = create_or_delete_trace_kprobe(cmd);
1895                 if (ret)
1896                         pr_warn("Failed to add event(%d): %s\n", ret, cmd);
1897 
1898                 cmd = p;
1899         }
1900 
1901         enable_boot_kprobe_events();
1902 }
1903 
1904 /*
1905  * Register dynevent at core_initcall. This allows kernel to setup kprobe
1906  * events in postcore_initcall without tracefs.
1907  */
1908 static __init int init_kprobe_trace_early(void)
1909 {
1910         int ret;
1911 
1912         ret = dyn_event_register(&trace_kprobe_ops);
1913         if (ret)
1914                 return ret;
1915 
1916         if (register_module_notifier(&trace_kprobe_module_nb))
1917                 return -EINVAL;
1918 
1919         return 0;
1920 }
1921 core_initcall(init_kprobe_trace_early);
1922 
1923 /* Make a tracefs interface for controlling probe points */
1924 static __init int init_kprobe_trace(void)
1925 {
1926         int ret;
1927         struct dentry *entry;
1928 
1929         ret = tracing_init_dentry();
1930         if (ret)
1931                 return 0;
1932 
1933         entry = tracefs_create_file("kprobe_events", 0644, NULL,
1934                                     NULL, &kprobe_events_ops);
1935 
1936         /* Event list interface */
1937         if (!entry)
1938                 pr_warn("Could not create tracefs 'kprobe_events' entry\n");
1939 
1940         /* Profile interface */
1941         entry = tracefs_create_file("kprobe_profile", 0444, NULL,
1942                                     NULL, &kprobe_profile_ops);
1943 
1944         if (!entry)
1945                 pr_warn("Could not create tracefs 'kprobe_profile' entry\n");
1946 
1947         setup_boot_kprobe_events();
1948 
1949         return 0;
1950 }
1951 fs_initcall(init_kprobe_trace);
1952 
1953 
1954 #ifdef CONFIG_FTRACE_STARTUP_TEST
1955 static __init struct trace_event_file *
1956 find_trace_probe_file(struct trace_kprobe *tk, struct trace_array *tr)
1957 {
1958         struct trace_event_file *file;
1959 
1960         list_for_each_entry(file, &tr->events, list)
1961                 if (file->event_call == trace_probe_event_call(&tk->tp))
1962                         return file;
1963 
1964         return NULL;
1965 }
1966 
1967 /*
1968  * Nobody but us can call enable_trace_kprobe/disable_trace_kprobe at this
1969  * stage, we can do this lockless.
1970  */
1971 static __init int kprobe_trace_self_tests_init(void)
1972 {
1973         int ret, warn = 0;
1974         int (*target)(int, int, int, int, int, int);
1975         struct trace_kprobe *tk;
1976         struct trace_event_file *file;
1977 
1978         if (tracing_is_disabled())
1979                 return -ENODEV;
1980 
1981         if (tracing_selftest_disabled)
1982                 return 0;
1983 
1984         target = kprobe_trace_selftest_target;
1985 
1986         pr_info("Testing kprobe tracing: ");
1987 
1988         ret = create_or_delete_trace_kprobe("p:testprobe kprobe_trace_selftest_target $stack $stack0 +0($stack)");
1989         if (WARN_ON_ONCE(ret)) {
1990                 pr_warn("error on probing function entry.\n");
1991                 warn++;
1992         } else {
1993                 /* Enable trace point */
1994                 tk = find_trace_kprobe("testprobe", KPROBE_EVENT_SYSTEM);
1995                 if (WARN_ON_ONCE(tk == NULL)) {
1996                         pr_warn("error on getting new probe.\n");
1997                         warn++;
1998                 } else {
1999                         file = find_trace_probe_file(tk, top_trace_array());
2000                         if (WARN_ON_ONCE(file == NULL)) {
2001                                 pr_warn("error on getting probe file.\n");
2002                                 warn++;
2003                         } else
2004                                 enable_trace_kprobe(
2005                                         trace_probe_event_call(&tk->tp), file);
2006                 }
2007         }
2008 
2009         ret = create_or_delete_trace_kprobe("r:testprobe2 kprobe_trace_selftest_target $retval");
2010         if (WARN_ON_ONCE(ret)) {
2011                 pr_warn("error on probing function return.\n");
2012                 warn++;
2013         } else {
2014                 /* Enable trace point */
2015                 tk = find_trace_kprobe("testprobe2", KPROBE_EVENT_SYSTEM);
2016                 if (WARN_ON_ONCE(tk == NULL)) {
2017                         pr_warn("error on getting 2nd new probe.\n");
2018                         warn++;
2019                 } else {
2020                         file = find_trace_probe_file(tk, top_trace_array());
2021                         if (WARN_ON_ONCE(file == NULL)) {
2022                                 pr_warn("error on getting probe file.\n");
2023                                 warn++;
2024                         } else
2025                                 enable_trace_kprobe(
2026                                         trace_probe_event_call(&tk->tp), file);
2027                 }
2028         }
2029 
2030         if (warn)
2031                 goto end;
2032 
2033         ret = target(1, 2, 3, 4, 5, 6);
2034 
2035         /*
2036          * Not expecting an error here, the check is only to prevent the
2037          * optimizer from removing the call to target() as otherwise there
2038          * are no side-effects and the call is never performed.
2039          */
2040         if (ret != 21)
2041                 warn++;
2042 
2043         /* Disable trace points before removing it */
2044         tk = find_trace_kprobe("testprobe", KPROBE_EVENT_SYSTEM);
2045         if (WARN_ON_ONCE(tk == NULL)) {
2046                 pr_warn("error on getting test probe.\n");
2047                 warn++;
2048         } else {
2049                 if (trace_kprobe_nhit(tk) != 1) {
2050                         pr_warn("incorrect number of testprobe hits\n");
2051                         warn++;
2052                 }
2053 
2054                 file = find_trace_probe_file(tk, top_trace_array());
2055                 if (WARN_ON_ONCE(file == NULL)) {
2056                         pr_warn("error on getting probe file.\n");
2057                         warn++;
2058                 } else
2059                         disable_trace_kprobe(
2060                                 trace_probe_event_call(&tk->tp), file);
2061         }
2062 
2063         tk = find_trace_kprobe("testprobe2", KPROBE_EVENT_SYSTEM);
2064         if (WARN_ON_ONCE(tk == NULL)) {
2065                 pr_warn("error on getting 2nd test probe.\n");
2066                 warn++;
2067         } else {
2068                 if (trace_kprobe_nhit(tk) != 1) {
2069                         pr_warn("incorrect number of testprobe2 hits\n");
2070                         warn++;
2071                 }
2072 
2073                 file = find_trace_probe_file(tk, top_trace_array());
2074                 if (WARN_ON_ONCE(file == NULL)) {
2075                         pr_warn("error on getting probe file.\n");
2076                         warn++;
2077                 } else
2078                         disable_trace_kprobe(
2079                                 trace_probe_event_call(&tk->tp), file);
2080         }
2081 
2082         ret = create_or_delete_trace_kprobe("-:testprobe");
2083         if (WARN_ON_ONCE(ret)) {
2084                 pr_warn("error on deleting a probe.\n");
2085                 warn++;
2086         }
2087 
2088         ret = create_or_delete_trace_kprobe("-:testprobe2");
2089         if (WARN_ON_ONCE(ret)) {
2090                 pr_warn("error on deleting a probe.\n");
2091                 warn++;
2092         }
2093 
2094 end:
2095         ret = dyn_events_release_all(&trace_kprobe_ops);
2096         if (WARN_ON_ONCE(ret)) {
2097                 pr_warn("error on cleaning up probes.\n");
2098                 warn++;
2099         }
2100         /*
2101          * Wait for the optimizer work to finish. Otherwise it might fiddle
2102          * with probes in already freed __init text.
2103          */
2104         wait_for_kprobe_optimizer();
2105         if (warn)
2106                 pr_cont("NG: Some tests are failed. Please check them.\n");
2107         else
2108                 pr_cont("OK\n");
2109         return 0;
2110 }
2111 
2112 late_initcall(kprobe_trace_self_tests_init);
2113 
2114 #endif
2115 

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