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

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

Version: ~ [ linux-5.9-rc6 ] ~ [ linux-5.8.10 ] ~ [ linux-5.7.19 ] ~ [ linux-5.6.19 ] ~ [ linux-5.5.19 ] ~ [ linux-5.4.66 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.146 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.198 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.236 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.236 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.19.8 ] ~ [ linux-3.18.140 ] ~ [ linux-3.17.8 ] ~ [ linux-3.16.85 ] ~ [ 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-2.6.32.71 ] ~ [ 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  * Common code for probe-based Dynamic events.
  3  *
  4  * This program is free software; you can redistribute it and/or modify
  5  * it under the terms of the GNU General Public License version 2 as
  6  * published by the Free Software Foundation.
  7  *
  8  * This program is distributed in the hope that it will be useful,
  9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
 10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 11  * GNU General Public License for more details.
 12  *
 13  * You should have received a copy of the GNU General Public License
 14  * along with this program; if not, write to the Free Software
 15  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 16  *
 17  * This code was copied from kernel/trace/trace_kprobe.c written by
 18  * Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
 19  *
 20  * Updates to make this generic:
 21  * Copyright (C) IBM Corporation, 2010-2011
 22  * Author:     Srikar Dronamraju
 23  */
 24 
 25 #include "trace_probe.h"
 26 
 27 const char *reserved_field_names[] = {
 28         "common_type",
 29         "common_flags",
 30         "common_preempt_count",
 31         "common_pid",
 32         "common_tgid",
 33         FIELD_STRING_IP,
 34         FIELD_STRING_RETIP,
 35         FIELD_STRING_FUNC,
 36 };
 37 
 38 /* Printing function type */
 39 #define PRINT_TYPE_FUNC_NAME(type)      print_type_##type
 40 #define PRINT_TYPE_FMT_NAME(type)       print_type_format_##type
 41 
 42 /* Printing  in basic type function template */
 43 #define DEFINE_BASIC_PRINT_TYPE_FUNC(type, fmt, cast)                   \
 44 static __kprobes int PRINT_TYPE_FUNC_NAME(type)(struct trace_seq *s,    \
 45                                                 const char *name,       \
 46                                                 void *data, void *ent)\
 47 {                                                                       \
 48         return trace_seq_printf(s, " %s=" fmt, name, (cast)*(type *)data);\
 49 }                                                                       \
 50 static const char PRINT_TYPE_FMT_NAME(type)[] = fmt;
 51 
 52 DEFINE_BASIC_PRINT_TYPE_FUNC(u8, "%x", unsigned int)
 53 DEFINE_BASIC_PRINT_TYPE_FUNC(u16, "%x", unsigned int)
 54 DEFINE_BASIC_PRINT_TYPE_FUNC(u32, "%lx", unsigned long)
 55 DEFINE_BASIC_PRINT_TYPE_FUNC(u64, "%llx", unsigned long long)
 56 DEFINE_BASIC_PRINT_TYPE_FUNC(s8, "%d", int)
 57 DEFINE_BASIC_PRINT_TYPE_FUNC(s16, "%d", int)
 58 DEFINE_BASIC_PRINT_TYPE_FUNC(s32, "%ld", long)
 59 DEFINE_BASIC_PRINT_TYPE_FUNC(s64, "%lld", long long)
 60 
 61 static inline void *get_rloc_data(u32 *dl)
 62 {
 63         return (u8 *)dl + get_rloc_offs(*dl);
 64 }
 65 
 66 /* For data_loc conversion */
 67 static inline void *get_loc_data(u32 *dl, void *ent)
 68 {
 69         return (u8 *)ent + get_rloc_offs(*dl);
 70 }
 71 
 72 /* For defining macros, define string/string_size types */
 73 typedef u32 string;
 74 typedef u32 string_size;
 75 
 76 /* Print type function for string type */
 77 static __kprobes int PRINT_TYPE_FUNC_NAME(string)(struct trace_seq *s,
 78                                                   const char *name,
 79                                                   void *data, void *ent)
 80 {
 81         int len = *(u32 *)data >> 16;
 82 
 83         if (!len)
 84                 return trace_seq_printf(s, " %s=(fault)", name);
 85         else
 86                 return trace_seq_printf(s, " %s=\"%s\"", name,
 87                                         (const char *)get_loc_data(data, ent));
 88 }
 89 
 90 static const char PRINT_TYPE_FMT_NAME(string)[] = "\\\"%s\\\"";
 91 
 92 #define FETCH_FUNC_NAME(method, type)   fetch_##method##_##type
 93 /*
 94  * Define macro for basic types - we don't need to define s* types, because
 95  * we have to care only about bitwidth at recording time.
 96  */
 97 #define DEFINE_BASIC_FETCH_FUNCS(method) \
 98 DEFINE_FETCH_##method(u8)               \
 99 DEFINE_FETCH_##method(u16)              \
100 DEFINE_FETCH_##method(u32)              \
101 DEFINE_FETCH_##method(u64)
102 
103 #define CHECK_FETCH_FUNCS(method, fn)                   \
104         (((FETCH_FUNC_NAME(method, u8) == fn) ||        \
105           (FETCH_FUNC_NAME(method, u16) == fn) ||       \
106           (FETCH_FUNC_NAME(method, u32) == fn) ||       \
107           (FETCH_FUNC_NAME(method, u64) == fn) ||       \
108           (FETCH_FUNC_NAME(method, string) == fn) ||    \
109           (FETCH_FUNC_NAME(method, string_size) == fn)) \
110          && (fn != NULL))
111 
112 /* Data fetch function templates */
113 #define DEFINE_FETCH_reg(type)                                          \
114 static __kprobes void FETCH_FUNC_NAME(reg, type)(struct pt_regs *regs,  \
115                                         void *offset, void *dest)       \
116 {                                                                       \
117         *(type *)dest = (type)regs_get_register(regs,                   \
118                                 (unsigned int)((unsigned long)offset)); \
119 }
120 DEFINE_BASIC_FETCH_FUNCS(reg)
121 /* No string on the register */
122 #define fetch_reg_string        NULL
123 #define fetch_reg_string_size   NULL
124 
125 #define DEFINE_FETCH_stack(type)                                        \
126 static __kprobes void FETCH_FUNC_NAME(stack, type)(struct pt_regs *regs,\
127                                           void *offset, void *dest)     \
128 {                                                                       \
129         *(type *)dest = (type)regs_get_kernel_stack_nth(regs,           \
130                                 (unsigned int)((unsigned long)offset)); \
131 }
132 DEFINE_BASIC_FETCH_FUNCS(stack)
133 /* No string on the stack entry */
134 #define fetch_stack_string      NULL
135 #define fetch_stack_string_size NULL
136 
137 #define DEFINE_FETCH_retval(type)                                       \
138 static __kprobes void FETCH_FUNC_NAME(retval, type)(struct pt_regs *regs,\
139                                           void *dummy, void *dest)      \
140 {                                                                       \
141         *(type *)dest = (type)regs_return_value(regs);                  \
142 }
143 DEFINE_BASIC_FETCH_FUNCS(retval)
144 /* No string on the retval */
145 #define fetch_retval_string             NULL
146 #define fetch_retval_string_size        NULL
147 
148 #define DEFINE_FETCH_memory(type)                                       \
149 static __kprobes void FETCH_FUNC_NAME(memory, type)(struct pt_regs *regs,\
150                                           void *addr, void *dest)       \
151 {                                                                       \
152         type retval;                                                    \
153         if (probe_kernel_address(addr, retval))                         \
154                 *(type *)dest = 0;                                      \
155         else                                                            \
156                 *(type *)dest = retval;                                 \
157 }
158 DEFINE_BASIC_FETCH_FUNCS(memory)
159 /*
160  * Fetch a null-terminated string. Caller MUST set *(u32 *)dest with max
161  * length and relative data location.
162  */
163 static __kprobes void FETCH_FUNC_NAME(memory, string)(struct pt_regs *regs,
164                                                       void *addr, void *dest)
165 {
166         long ret;
167         int maxlen = get_rloc_len(*(u32 *)dest);
168         u8 *dst = get_rloc_data(dest);
169         u8 *src = addr;
170         mm_segment_t old_fs = get_fs();
171 
172         if (!maxlen)
173                 return;
174 
175         /*
176          * Try to get string again, since the string can be changed while
177          * probing.
178          */
179         set_fs(KERNEL_DS);
180         pagefault_disable();
181 
182         do
183                 ret = __copy_from_user_inatomic(dst++, src++, 1);
184         while (dst[-1] && ret == 0 && src - (u8 *)addr < maxlen);
185 
186         dst[-1] = '\0';
187         pagefault_enable();
188         set_fs(old_fs);
189 
190         if (ret < 0) {  /* Failed to fetch string */
191                 ((u8 *)get_rloc_data(dest))[0] = '\0';
192                 *(u32 *)dest = make_data_rloc(0, get_rloc_offs(*(u32 *)dest));
193         } else {
194                 *(u32 *)dest = make_data_rloc(src - (u8 *)addr,
195                                               get_rloc_offs(*(u32 *)dest));
196         }
197 }
198 
199 /* Return the length of string -- including null terminal byte */
200 static __kprobes void FETCH_FUNC_NAME(memory, string_size)(struct pt_regs *regs,
201                                                         void *addr, void *dest)
202 {
203         mm_segment_t old_fs;
204         int ret, len = 0;
205         u8 c;
206 
207         old_fs = get_fs();
208         set_fs(KERNEL_DS);
209         pagefault_disable();
210 
211         do {
212                 ret = __copy_from_user_inatomic(&c, (u8 *)addr + len, 1);
213                 len++;
214         } while (c && ret == 0 && len < MAX_STRING_SIZE);
215 
216         pagefault_enable();
217         set_fs(old_fs);
218 
219         if (ret < 0)    /* Failed to check the length */
220                 *(u32 *)dest = 0;
221         else
222                 *(u32 *)dest = len;
223 }
224 
225 /* Memory fetching by symbol */
226 struct symbol_cache {
227         char            *symbol;
228         long            offset;
229         unsigned long   addr;
230 };
231 
232 static unsigned long update_symbol_cache(struct symbol_cache *sc)
233 {
234         sc->addr = (unsigned long)kallsyms_lookup_name(sc->symbol);
235 
236         if (sc->addr)
237                 sc->addr += sc->offset;
238 
239         return sc->addr;
240 }
241 
242 static void free_symbol_cache(struct symbol_cache *sc)
243 {
244         kfree(sc->symbol);
245         kfree(sc);
246 }
247 
248 static struct symbol_cache *alloc_symbol_cache(const char *sym, long offset)
249 {
250         struct symbol_cache *sc;
251 
252         if (!sym || strlen(sym) == 0)
253                 return NULL;
254 
255         sc = kzalloc(sizeof(struct symbol_cache), GFP_KERNEL);
256         if (!sc)
257                 return NULL;
258 
259         sc->symbol = kstrdup(sym, GFP_KERNEL);
260         if (!sc->symbol) {
261                 kfree(sc);
262                 return NULL;
263         }
264         sc->offset = offset;
265         update_symbol_cache(sc);
266 
267         return sc;
268 }
269 
270 #define DEFINE_FETCH_symbol(type)                                       \
271 static __kprobes void FETCH_FUNC_NAME(symbol, type)(struct pt_regs *regs,\
272                                           void *data, void *dest)       \
273 {                                                                       \
274         struct symbol_cache *sc = data;                                 \
275         if (sc->addr)                                                   \
276                 fetch_memory_##type(regs, (void *)sc->addr, dest);      \
277         else                                                            \
278                 *(type *)dest = 0;                                      \
279 }
280 DEFINE_BASIC_FETCH_FUNCS(symbol)
281 DEFINE_FETCH_symbol(string)
282 DEFINE_FETCH_symbol(string_size)
283 
284 /* Dereference memory access function */
285 struct deref_fetch_param {
286         struct fetch_param      orig;
287         long                    offset;
288 };
289 
290 #define DEFINE_FETCH_deref(type)                                        \
291 static __kprobes void FETCH_FUNC_NAME(deref, type)(struct pt_regs *regs,\
292                                             void *data, void *dest)     \
293 {                                                                       \
294         struct deref_fetch_param *dprm = data;                          \
295         unsigned long addr;                                             \
296         call_fetch(&dprm->orig, regs, &addr);                           \
297         if (addr) {                                                     \
298                 addr += dprm->offset;                                   \
299                 fetch_memory_##type(regs, (void *)addr, dest);          \
300         } else                                                          \
301                 *(type *)dest = 0;                                      \
302 }
303 DEFINE_BASIC_FETCH_FUNCS(deref)
304 DEFINE_FETCH_deref(string)
305 DEFINE_FETCH_deref(string_size)
306 
307 static __kprobes void update_deref_fetch_param(struct deref_fetch_param *data)
308 {
309         if (CHECK_FETCH_FUNCS(deref, data->orig.fn))
310                 update_deref_fetch_param(data->orig.data);
311         else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn))
312                 update_symbol_cache(data->orig.data);
313 }
314 
315 static __kprobes void free_deref_fetch_param(struct deref_fetch_param *data)
316 {
317         if (CHECK_FETCH_FUNCS(deref, data->orig.fn))
318                 free_deref_fetch_param(data->orig.data);
319         else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn))
320                 free_symbol_cache(data->orig.data);
321         kfree(data);
322 }
323 
324 /* Bitfield fetch function */
325 struct bitfield_fetch_param {
326         struct fetch_param      orig;
327         unsigned char           hi_shift;
328         unsigned char           low_shift;
329 };
330 
331 #define DEFINE_FETCH_bitfield(type)                                     \
332 static __kprobes void FETCH_FUNC_NAME(bitfield, type)(struct pt_regs *regs,\
333                                             void *data, void *dest)     \
334 {                                                                       \
335         struct bitfield_fetch_param *bprm = data;                       \
336         type buf = 0;                                                   \
337         call_fetch(&bprm->orig, regs, &buf);                            \
338         if (buf) {                                                      \
339                 buf <<= bprm->hi_shift;                                 \
340                 buf >>= bprm->low_shift;                                \
341         }                                                               \
342         *(type *)dest = buf;                                            \
343 }
344 
345 DEFINE_BASIC_FETCH_FUNCS(bitfield)
346 #define fetch_bitfield_string           NULL
347 #define fetch_bitfield_string_size      NULL
348 
349 static __kprobes void
350 update_bitfield_fetch_param(struct bitfield_fetch_param *data)
351 {
352         /*
353          * Don't check the bitfield itself, because this must be the
354          * last fetch function.
355          */
356         if (CHECK_FETCH_FUNCS(deref, data->orig.fn))
357                 update_deref_fetch_param(data->orig.data);
358         else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn))
359                 update_symbol_cache(data->orig.data);
360 }
361 
362 static __kprobes void
363 free_bitfield_fetch_param(struct bitfield_fetch_param *data)
364 {
365         /*
366          * Don't check the bitfield itself, because this must be the
367          * last fetch function.
368          */
369         if (CHECK_FETCH_FUNCS(deref, data->orig.fn))
370                 free_deref_fetch_param(data->orig.data);
371         else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn))
372                 free_symbol_cache(data->orig.data);
373 
374         kfree(data);
375 }
376 
377 /* Default (unsigned long) fetch type */
378 #define __DEFAULT_FETCH_TYPE(t) u##t
379 #define _DEFAULT_FETCH_TYPE(t) __DEFAULT_FETCH_TYPE(t)
380 #define DEFAULT_FETCH_TYPE _DEFAULT_FETCH_TYPE(BITS_PER_LONG)
381 #define DEFAULT_FETCH_TYPE_STR __stringify(DEFAULT_FETCH_TYPE)
382 
383 #define ASSIGN_FETCH_FUNC(method, type) \
384         [FETCH_MTD_##method] = FETCH_FUNC_NAME(method, type)
385 
386 #define __ASSIGN_FETCH_TYPE(_name, ptype, ftype, _size, sign, _fmttype) \
387         {.name = _name,                         \
388          .size = _size,                                 \
389          .is_signed = sign,                             \
390          .print = PRINT_TYPE_FUNC_NAME(ptype),          \
391          .fmt = PRINT_TYPE_FMT_NAME(ptype),             \
392          .fmttype = _fmttype,                           \
393          .fetch = {                                     \
394 ASSIGN_FETCH_FUNC(reg, ftype),                          \
395 ASSIGN_FETCH_FUNC(stack, ftype),                        \
396 ASSIGN_FETCH_FUNC(retval, ftype),                       \
397 ASSIGN_FETCH_FUNC(memory, ftype),                       \
398 ASSIGN_FETCH_FUNC(symbol, ftype),                       \
399 ASSIGN_FETCH_FUNC(deref, ftype),                        \
400 ASSIGN_FETCH_FUNC(bitfield, ftype),                     \
401           }                                             \
402         }
403 
404 #define ASSIGN_FETCH_TYPE(ptype, ftype, sign)                   \
405         __ASSIGN_FETCH_TYPE(#ptype, ptype, ftype, sizeof(ftype), sign, #ptype)
406 
407 #define FETCH_TYPE_STRING       0
408 #define FETCH_TYPE_STRSIZE      1
409 
410 /* Fetch type information table */
411 static const struct fetch_type fetch_type_table[] = {
412         /* Special types */
413         [FETCH_TYPE_STRING] = __ASSIGN_FETCH_TYPE("string", string, string,
414                                         sizeof(u32), 1, "__data_loc char[]"),
415         [FETCH_TYPE_STRSIZE] = __ASSIGN_FETCH_TYPE("string_size", u32,
416                                         string_size, sizeof(u32), 0, "u32"),
417         /* Basic types */
418         ASSIGN_FETCH_TYPE(u8,  u8,  0),
419         ASSIGN_FETCH_TYPE(u16, u16, 0),
420         ASSIGN_FETCH_TYPE(u32, u32, 0),
421         ASSIGN_FETCH_TYPE(u64, u64, 0),
422         ASSIGN_FETCH_TYPE(s8,  u8,  1),
423         ASSIGN_FETCH_TYPE(s16, u16, 1),
424         ASSIGN_FETCH_TYPE(s32, u32, 1),
425         ASSIGN_FETCH_TYPE(s64, u64, 1),
426 };
427 
428 static const struct fetch_type *find_fetch_type(const char *type)
429 {
430         int i;
431 
432         if (!type)
433                 type = DEFAULT_FETCH_TYPE_STR;
434 
435         /* Special case: bitfield */
436         if (*type == 'b') {
437                 unsigned long bs;
438 
439                 type = strchr(type, '/');
440                 if (!type)
441                         goto fail;
442 
443                 type++;
444                 if (kstrtoul(type, 0, &bs))
445                         goto fail;
446 
447                 switch (bs) {
448                 case 8:
449                         return find_fetch_type("u8");
450                 case 16:
451                         return find_fetch_type("u16");
452                 case 32:
453                         return find_fetch_type("u32");
454                 case 64:
455                         return find_fetch_type("u64");
456                 default:
457                         goto fail;
458                 }
459         }
460 
461         for (i = 0; i < ARRAY_SIZE(fetch_type_table); i++)
462                 if (strcmp(type, fetch_type_table[i].name) == 0)
463                         return &fetch_type_table[i];
464 
465 fail:
466         return NULL;
467 }
468 
469 /* Special function : only accept unsigned long */
470 static __kprobes void fetch_stack_address(struct pt_regs *regs,
471                                         void *dummy, void *dest)
472 {
473         *(unsigned long *)dest = kernel_stack_pointer(regs);
474 }
475 
476 static fetch_func_t get_fetch_size_function(const struct fetch_type *type,
477                                         fetch_func_t orig_fn)
478 {
479         int i;
480 
481         if (type != &fetch_type_table[FETCH_TYPE_STRING])
482                 return NULL;    /* Only string type needs size function */
483 
484         for (i = 0; i < FETCH_MTD_END; i++)
485                 if (type->fetch[i] == orig_fn)
486                         return fetch_type_table[FETCH_TYPE_STRSIZE].fetch[i];
487 
488         WARN_ON(1);     /* This should not happen */
489 
490         return NULL;
491 }
492 
493 /* Split symbol and offset. */
494 int traceprobe_split_symbol_offset(char *symbol, unsigned long *offset)
495 {
496         char *tmp;
497         int ret;
498 
499         if (!offset)
500                 return -EINVAL;
501 
502         tmp = strchr(symbol, '+');
503         if (tmp) {
504                 /* skip sign because kstrtoul doesn't accept '+' */
505                 ret = kstrtoul(tmp + 1, 0, offset);
506                 if (ret)
507                         return ret;
508 
509                 *tmp = '\0';
510         } else
511                 *offset = 0;
512 
513         return 0;
514 }
515 
516 #define PARAM_MAX_STACK (THREAD_SIZE / sizeof(unsigned long))
517 
518 static int parse_probe_vars(char *arg, const struct fetch_type *t,
519                             struct fetch_param *f, bool is_return)
520 {
521         int ret = 0;
522         unsigned long param;
523 
524         if (strcmp(arg, "retval") == 0) {
525                 if (is_return)
526                         f->fn = t->fetch[FETCH_MTD_retval];
527                 else
528                         ret = -EINVAL;
529         } else if (strncmp(arg, "stack", 5) == 0) {
530                 if (arg[5] == '\0') {
531                         if (strcmp(t->name, DEFAULT_FETCH_TYPE_STR) == 0)
532                                 f->fn = fetch_stack_address;
533                         else
534                                 ret = -EINVAL;
535                 } else if (isdigit(arg[5])) {
536                         ret = kstrtoul(arg + 5, 10, &param);
537                         if (ret || param > PARAM_MAX_STACK)
538                                 ret = -EINVAL;
539                         else {
540                                 f->fn = t->fetch[FETCH_MTD_stack];
541                                 f->data = (void *)param;
542                         }
543                 } else
544                         ret = -EINVAL;
545         } else
546                 ret = -EINVAL;
547 
548         return ret;
549 }
550 
551 /* Recursive argument parser */
552 static int parse_probe_arg(char *arg, const struct fetch_type *t,
553                      struct fetch_param *f, bool is_return, bool is_kprobe)
554 {
555         unsigned long param;
556         long offset;
557         char *tmp;
558         int ret;
559 
560         ret = 0;
561 
562         /* Until uprobe_events supports only reg arguments */
563         if (!is_kprobe && arg[0] != '%')
564                 return -EINVAL;
565 
566         switch (arg[0]) {
567         case '$':
568                 ret = parse_probe_vars(arg + 1, t, f, is_return);
569                 break;
570 
571         case '%':       /* named register */
572                 ret = regs_query_register_offset(arg + 1);
573                 if (ret >= 0) {
574                         f->fn = t->fetch[FETCH_MTD_reg];
575                         f->data = (void *)(unsigned long)ret;
576                         ret = 0;
577                 }
578                 break;
579 
580         case '@':       /* memory or symbol */
581                 if (isdigit(arg[1])) {
582                         ret = kstrtoul(arg + 1, 0, &param);
583                         if (ret)
584                                 break;
585 
586                         f->fn = t->fetch[FETCH_MTD_memory];
587                         f->data = (void *)param;
588                 } else {
589                         ret = traceprobe_split_symbol_offset(arg + 1, &offset);
590                         if (ret)
591                                 break;
592 
593                         f->data = alloc_symbol_cache(arg + 1, offset);
594                         if (f->data)
595                                 f->fn = t->fetch[FETCH_MTD_symbol];
596                 }
597                 break;
598 
599         case '+':       /* deref memory */
600                 arg++;  /* Skip '+', because kstrtol() rejects it. */
601         case '-':
602                 tmp = strchr(arg, '(');
603                 if (!tmp)
604                         break;
605 
606                 *tmp = '\0';
607                 ret = kstrtol(arg, 0, &offset);
608 
609                 if (ret)
610                         break;
611 
612                 arg = tmp + 1;
613                 tmp = strrchr(arg, ')');
614 
615                 if (tmp) {
616                         struct deref_fetch_param        *dprm;
617                         const struct fetch_type         *t2;
618 
619                         t2 = find_fetch_type(NULL);
620                         *tmp = '\0';
621                         dprm = kzalloc(sizeof(struct deref_fetch_param), GFP_KERNEL);
622 
623                         if (!dprm)
624                                 return -ENOMEM;
625 
626                         dprm->offset = offset;
627                         ret = parse_probe_arg(arg, t2, &dprm->orig, is_return,
628                                                         is_kprobe);
629                         if (ret)
630                                 kfree(dprm);
631                         else {
632                                 f->fn = t->fetch[FETCH_MTD_deref];
633                                 f->data = (void *)dprm;
634                         }
635                 }
636                 break;
637         }
638         if (!ret && !f->fn) {   /* Parsed, but do not find fetch method */
639                 pr_info("%s type has no corresponding fetch method.\n", t->name);
640                 ret = -EINVAL;
641         }
642 
643         return ret;
644 }
645 
646 #define BYTES_TO_BITS(nb)       ((BITS_PER_LONG * (nb)) / sizeof(long))
647 
648 /* Bitfield type needs to be parsed into a fetch function */
649 static int __parse_bitfield_probe_arg(const char *bf,
650                                       const struct fetch_type *t,
651                                       struct fetch_param *f)
652 {
653         struct bitfield_fetch_param *bprm;
654         unsigned long bw, bo;
655         char *tail;
656 
657         if (*bf != 'b')
658                 return 0;
659 
660         bprm = kzalloc(sizeof(*bprm), GFP_KERNEL);
661         if (!bprm)
662                 return -ENOMEM;
663 
664         bprm->orig = *f;
665         f->fn = t->fetch[FETCH_MTD_bitfield];
666         f->data = (void *)bprm;
667         bw = simple_strtoul(bf + 1, &tail, 0);  /* Use simple one */
668 
669         if (bw == 0 || *tail != '@')
670                 return -EINVAL;
671 
672         bf = tail + 1;
673         bo = simple_strtoul(bf, &tail, 0);
674 
675         if (tail == bf || *tail != '/')
676                 return -EINVAL;
677 
678         bprm->hi_shift = BYTES_TO_BITS(t->size) - (bw + bo);
679         bprm->low_shift = bprm->hi_shift + bo;
680 
681         return (BYTES_TO_BITS(t->size) < (bw + bo)) ? -EINVAL : 0;
682 }
683 
684 /* String length checking wrapper */
685 int traceprobe_parse_probe_arg(char *arg, ssize_t *size,
686                 struct probe_arg *parg, bool is_return, bool is_kprobe)
687 {
688         const char *t;
689         int ret;
690 
691         if (strlen(arg) > MAX_ARGSTR_LEN) {
692                 pr_info("Argument is too long.: %s\n",  arg);
693                 return -ENOSPC;
694         }
695         parg->comm = kstrdup(arg, GFP_KERNEL);
696         if (!parg->comm) {
697                 pr_info("Failed to allocate memory for command '%s'.\n", arg);
698                 return -ENOMEM;
699         }
700         t = strchr(parg->comm, ':');
701         if (t) {
702                 arg[t - parg->comm] = '\0';
703                 t++;
704         }
705         parg->type = find_fetch_type(t);
706         if (!parg->type) {
707                 pr_info("Unsupported type: %s\n", t);
708                 return -EINVAL;
709         }
710         parg->offset = *size;
711         *size += parg->type->size;
712         ret = parse_probe_arg(arg, parg->type, &parg->fetch, is_return, is_kprobe);
713 
714         if (ret >= 0 && t != NULL)
715                 ret = __parse_bitfield_probe_arg(t, parg->type, &parg->fetch);
716 
717         if (ret >= 0) {
718                 parg->fetch_size.fn = get_fetch_size_function(parg->type,
719                                                               parg->fetch.fn);
720                 parg->fetch_size.data = parg->fetch.data;
721         }
722 
723         return ret;
724 }
725 
726 /* Return 1 if name is reserved or already used by another argument */
727 int traceprobe_conflict_field_name(const char *name,
728                                struct probe_arg *args, int narg)
729 {
730         int i;
731 
732         for (i = 0; i < ARRAY_SIZE(reserved_field_names); i++)
733                 if (strcmp(reserved_field_names[i], name) == 0)
734                         return 1;
735 
736         for (i = 0; i < narg; i++)
737                 if (strcmp(args[i].name, name) == 0)
738                         return 1;
739 
740         return 0;
741 }
742 
743 void traceprobe_update_arg(struct probe_arg *arg)
744 {
745         if (CHECK_FETCH_FUNCS(bitfield, arg->fetch.fn))
746                 update_bitfield_fetch_param(arg->fetch.data);
747         else if (CHECK_FETCH_FUNCS(deref, arg->fetch.fn))
748                 update_deref_fetch_param(arg->fetch.data);
749         else if (CHECK_FETCH_FUNCS(symbol, arg->fetch.fn))
750                 update_symbol_cache(arg->fetch.data);
751 }
752 
753 void traceprobe_free_probe_arg(struct probe_arg *arg)
754 {
755         if (CHECK_FETCH_FUNCS(bitfield, arg->fetch.fn))
756                 free_bitfield_fetch_param(arg->fetch.data);
757         else if (CHECK_FETCH_FUNCS(deref, arg->fetch.fn))
758                 free_deref_fetch_param(arg->fetch.data);
759         else if (CHECK_FETCH_FUNCS(symbol, arg->fetch.fn))
760                 free_symbol_cache(arg->fetch.data);
761 
762         kfree(arg->name);
763         kfree(arg->comm);
764 }
765 
766 int traceprobe_command(const char *buf, int (*createfn)(int, char **))
767 {
768         char **argv;
769         int argc, ret;
770 
771         argc = 0;
772         ret = 0;
773         argv = argv_split(GFP_KERNEL, buf, &argc);
774         if (!argv)
775                 return -ENOMEM;
776 
777         if (argc)
778                 ret = createfn(argc, argv);
779 
780         argv_free(argv);
781 
782         return ret;
783 }
784 
785 #define WRITE_BUFSIZE  4096
786 
787 ssize_t traceprobe_probes_write(struct file *file, const char __user *buffer,
788                                 size_t count, loff_t *ppos,
789                                 int (*createfn)(int, char **))
790 {
791         char *kbuf, *tmp;
792         int ret = 0;
793         size_t done = 0;
794         size_t size;
795 
796         kbuf = kmalloc(WRITE_BUFSIZE, GFP_KERNEL);
797         if (!kbuf)
798                 return -ENOMEM;
799 
800         while (done < count) {
801                 size = count - done;
802 
803                 if (size >= WRITE_BUFSIZE)
804                         size = WRITE_BUFSIZE - 1;
805 
806                 if (copy_from_user(kbuf, buffer + done, size)) {
807                         ret = -EFAULT;
808                         goto out;
809                 }
810                 kbuf[size] = '\0';
811                 tmp = strchr(kbuf, '\n');
812 
813                 if (tmp) {
814                         *tmp = '\0';
815                         size = tmp - kbuf + 1;
816                 } else if (done + size < count) {
817                         pr_warning("Line length is too long: "
818                                    "Should be less than %d.", WRITE_BUFSIZE);
819                         ret = -EINVAL;
820                         goto out;
821                 }
822                 done += size;
823                 /* Remove comments */
824                 tmp = strchr(kbuf, '#');
825 
826                 if (tmp)
827                         *tmp = '\0';
828 
829                 ret = traceprobe_command(kbuf, createfn);
830                 if (ret)
831                         goto out;
832         }
833         ret = done;
834 
835 out:
836         kfree(kbuf);
837 
838         return ret;
839 }
840 

~ [ 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