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 #define pr_fmt(fmt) "trace_probe: " fmt
25
26 #include "trace_probe.h"
27
28 const char *reserved_field_names[] = {
29 "common_type",
30 "common_flags",
31 "common_preempt_count",
32 "common_pid",
33 "common_tgid",
34 FIELD_STRING_IP,
35 FIELD_STRING_RETIP,
36 FIELD_STRING_FUNC,
37 };
38
39 /* Printing in basic type function template */
40 #define DEFINE_BASIC_PRINT_TYPE_FUNC(tname, type, fmt) \
41 int PRINT_TYPE_FUNC_NAME(tname)(struct trace_seq *s, const char *name, \
42 void *data, void *ent) \
43 { \
44 trace_seq_printf(s, " %s=" fmt, name, *(type *)data); \
45 return !trace_seq_has_overflowed(s); \
46 } \
47 const char PRINT_TYPE_FMT_NAME(tname)[] = fmt; \
48 NOKPROBE_SYMBOL(PRINT_TYPE_FUNC_NAME(tname));
49
50 DEFINE_BASIC_PRINT_TYPE_FUNC(u8, u8, "%u")
51 DEFINE_BASIC_PRINT_TYPE_FUNC(u16, u16, "%u")
52 DEFINE_BASIC_PRINT_TYPE_FUNC(u32, u32, "%u")
53 DEFINE_BASIC_PRINT_TYPE_FUNC(u64, u64, "%Lu")
54 DEFINE_BASIC_PRINT_TYPE_FUNC(s8, s8, "%d")
55 DEFINE_BASIC_PRINT_TYPE_FUNC(s16, s16, "%d")
56 DEFINE_BASIC_PRINT_TYPE_FUNC(s32, s32, "%d")
57 DEFINE_BASIC_PRINT_TYPE_FUNC(s64, s64, "%Ld")
58 DEFINE_BASIC_PRINT_TYPE_FUNC(x8, u8, "0x%x")
59 DEFINE_BASIC_PRINT_TYPE_FUNC(x16, u16, "0x%x")
60 DEFINE_BASIC_PRINT_TYPE_FUNC(x32, u32, "0x%x")
61 DEFINE_BASIC_PRINT_TYPE_FUNC(x64, u64, "0x%Lx")
62
63 /* Print type function for string type */
PRINT_TYPE_FUNC_NAME(string)64 int PRINT_TYPE_FUNC_NAME(string)(struct trace_seq *s, const char *name,
65 void *data, void *ent)
66 {
67 int len = *(u32 *)data >> 16;
68
69 if (!len)
70 trace_seq_printf(s, " %s=(fault)", name);
71 else
72 trace_seq_printf(s, " %s=\"%s\"", name,
73 (const char *)get_loc_data(data, ent));
74 return !trace_seq_has_overflowed(s);
75 }
76 NOKPROBE_SYMBOL(PRINT_TYPE_FUNC_NAME(string));
77
78 const char PRINT_TYPE_FMT_NAME(string)[] = "\\\"%s\\\"";
79
80 #define CHECK_FETCH_FUNCS(method, fn) \
81 (((FETCH_FUNC_NAME(method, u8) == fn) || \
82 (FETCH_FUNC_NAME(method, u16) == fn) || \
83 (FETCH_FUNC_NAME(method, u32) == fn) || \
84 (FETCH_FUNC_NAME(method, u64) == fn) || \
85 (FETCH_FUNC_NAME(method, string) == fn) || \
86 (FETCH_FUNC_NAME(method, string_size) == fn)) \
87 && (fn != NULL))
88
89 /* Data fetch function templates */
90 #define DEFINE_FETCH_reg(type) \
91 void FETCH_FUNC_NAME(reg, type)(struct pt_regs *regs, void *offset, void *dest) \
92 { \
93 *(type *)dest = (type)regs_get_register(regs, \
94 (unsigned int)((unsigned long)offset)); \
95 } \
96 NOKPROBE_SYMBOL(FETCH_FUNC_NAME(reg, type));
97 DEFINE_BASIC_FETCH_FUNCS(reg)
98 /* No string on the register */
99 #define fetch_reg_string NULL
100 #define fetch_reg_string_size NULL
101
102 #define DEFINE_FETCH_retval(type) \
103 void FETCH_FUNC_NAME(retval, type)(struct pt_regs *regs, \
104 void *dummy, void *dest) \
105 { \
106 *(type *)dest = (type)regs_return_value(regs); \
107 } \
108 NOKPROBE_SYMBOL(FETCH_FUNC_NAME(retval, type));
109 DEFINE_BASIC_FETCH_FUNCS(retval)
110 /* No string on the retval */
111 #define fetch_retval_string NULL
112 #define fetch_retval_string_size NULL
113
114 /* Dereference memory access function */
115 struct deref_fetch_param {
116 struct fetch_param orig;
117 long offset;
118 fetch_func_t fetch;
119 fetch_func_t fetch_size;
120 };
121
122 #define DEFINE_FETCH_deref(type) \
123 void FETCH_FUNC_NAME(deref, type)(struct pt_regs *regs, \
124 void *data, void *dest) \
125 { \
126 struct deref_fetch_param *dprm = data; \
127 unsigned long addr; \
128 call_fetch(&dprm->orig, regs, &addr); \
129 if (addr) { \
130 addr += dprm->offset; \
131 dprm->fetch(regs, (void *)addr, dest); \
132 } else \
133 *(type *)dest = 0; \
134 } \
135 NOKPROBE_SYMBOL(FETCH_FUNC_NAME(deref, type));
136 DEFINE_BASIC_FETCH_FUNCS(deref)
DEFINE_FETCH_deref(string)137 DEFINE_FETCH_deref(string)
138
139 void FETCH_FUNC_NAME(deref, string_size)(struct pt_regs *regs,
140 void *data, void *dest)
141 {
142 struct deref_fetch_param *dprm = data;
143 unsigned long addr;
144
145 call_fetch(&dprm->orig, regs, &addr);
146 if (addr && dprm->fetch_size) {
147 addr += dprm->offset;
148 dprm->fetch_size(regs, (void *)addr, dest);
149 } else
150 *(string_size *)dest = 0;
151 }
152 NOKPROBE_SYMBOL(FETCH_FUNC_NAME(deref, string_size));
153
update_deref_fetch_param(struct deref_fetch_param * data)154 static void update_deref_fetch_param(struct deref_fetch_param *data)
155 {
156 if (CHECK_FETCH_FUNCS(deref, data->orig.fn))
157 update_deref_fetch_param(data->orig.data);
158 else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn))
159 update_symbol_cache(data->orig.data);
160 }
161 NOKPROBE_SYMBOL(update_deref_fetch_param);
162
free_deref_fetch_param(struct deref_fetch_param * data)163 static void free_deref_fetch_param(struct deref_fetch_param *data)
164 {
165 if (CHECK_FETCH_FUNCS(deref, data->orig.fn))
166 free_deref_fetch_param(data->orig.data);
167 else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn))
168 free_symbol_cache(data->orig.data);
169 kfree(data);
170 }
171 NOKPROBE_SYMBOL(free_deref_fetch_param);
172
173 /* Bitfield fetch function */
174 struct bitfield_fetch_param {
175 struct fetch_param orig;
176 unsigned char hi_shift;
177 unsigned char low_shift;
178 };
179
180 #define DEFINE_FETCH_bitfield(type) \
181 void FETCH_FUNC_NAME(bitfield, type)(struct pt_regs *regs, \
182 void *data, void *dest) \
183 { \
184 struct bitfield_fetch_param *bprm = data; \
185 type buf = 0; \
186 call_fetch(&bprm->orig, regs, &buf); \
187 if (buf) { \
188 buf <<= bprm->hi_shift; \
189 buf >>= bprm->low_shift; \
190 } \
191 *(type *)dest = buf; \
192 } \
193 NOKPROBE_SYMBOL(FETCH_FUNC_NAME(bitfield, type));
DEFINE_BASIC_FETCH_FUNCS(bitfield)194 DEFINE_BASIC_FETCH_FUNCS(bitfield)
195 #define fetch_bitfield_string NULL
196 #define fetch_bitfield_string_size NULL
197
198 static void
199 update_bitfield_fetch_param(struct bitfield_fetch_param *data)
200 {
201 /*
202 * Don't check the bitfield itself, because this must be the
203 * last fetch function.
204 */
205 if (CHECK_FETCH_FUNCS(deref, data->orig.fn))
206 update_deref_fetch_param(data->orig.data);
207 else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn))
208 update_symbol_cache(data->orig.data);
209 }
210
211 static void
free_bitfield_fetch_param(struct bitfield_fetch_param * data)212 free_bitfield_fetch_param(struct bitfield_fetch_param *data)
213 {
214 /*
215 * Don't check the bitfield itself, because this must be the
216 * last fetch function.
217 */
218 if (CHECK_FETCH_FUNCS(deref, data->orig.fn))
219 free_deref_fetch_param(data->orig.data);
220 else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn))
221 free_symbol_cache(data->orig.data);
222
223 kfree(data);
224 }
225
FETCH_FUNC_NAME(comm,string)226 void FETCH_FUNC_NAME(comm, string)(struct pt_regs *regs,
227 void *data, void *dest)
228 {
229 int maxlen = get_rloc_len(*(u32 *)dest);
230 u8 *dst = get_rloc_data(dest);
231 long ret;
232
233 if (!maxlen)
234 return;
235
236 ret = strlcpy(dst, current->comm, maxlen);
237 *(u32 *)dest = make_data_rloc(ret, get_rloc_offs(*(u32 *)dest));
238 }
239 NOKPROBE_SYMBOL(FETCH_FUNC_NAME(comm, string));
240
FETCH_FUNC_NAME(comm,string_size)241 void FETCH_FUNC_NAME(comm, string_size)(struct pt_regs *regs,
242 void *data, void *dest)
243 {
244 *(u32 *)dest = strlen(current->comm) + 1;
245 }
246 NOKPROBE_SYMBOL(FETCH_FUNC_NAME(comm, string_size));
247
find_fetch_type(const char * type,const struct fetch_type * ftbl)248 static const struct fetch_type *find_fetch_type(const char *type,
249 const struct fetch_type *ftbl)
250 {
251 int i;
252
253 if (!type)
254 type = DEFAULT_FETCH_TYPE_STR;
255
256 /* Special case: bitfield */
257 if (*type == 'b') {
258 unsigned long bs;
259
260 type = strchr(type, '/');
261 if (!type)
262 goto fail;
263
264 type++;
265 if (kstrtoul(type, 0, &bs))
266 goto fail;
267
268 switch (bs) {
269 case 8:
270 return find_fetch_type("u8", ftbl);
271 case 16:
272 return find_fetch_type("u16", ftbl);
273 case 32:
274 return find_fetch_type("u32", ftbl);
275 case 64:
276 return find_fetch_type("u64", ftbl);
277 default:
278 goto fail;
279 }
280 }
281
282 for (i = 0; ftbl[i].name; i++) {
283 if (strcmp(type, ftbl[i].name) == 0)
284 return &ftbl[i];
285 }
286
287 fail:
288 return NULL;
289 }
290
291 /* Special function : only accept unsigned long */
fetch_kernel_stack_address(struct pt_regs * regs,void * dummy,void * dest)292 static void fetch_kernel_stack_address(struct pt_regs *regs, void *dummy, void *dest)
293 {
294 *(unsigned long *)dest = kernel_stack_pointer(regs);
295 }
296 NOKPROBE_SYMBOL(fetch_kernel_stack_address);
297
fetch_user_stack_address(struct pt_regs * regs,void * dummy,void * dest)298 static void fetch_user_stack_address(struct pt_regs *regs, void *dummy, void *dest)
299 {
300 *(unsigned long *)dest = user_stack_pointer(regs);
301 }
302 NOKPROBE_SYMBOL(fetch_user_stack_address);
303
get_fetch_size_function(const struct fetch_type * type,fetch_func_t orig_fn,const struct fetch_type * ftbl)304 static fetch_func_t get_fetch_size_function(const struct fetch_type *type,
305 fetch_func_t orig_fn,
306 const struct fetch_type *ftbl)
307 {
308 int i;
309
310 if (type != &ftbl[FETCH_TYPE_STRING])
311 return NULL; /* Only string type needs size function */
312
313 for (i = 0; i < FETCH_MTD_END; i++)
314 if (type->fetch[i] == orig_fn)
315 return ftbl[FETCH_TYPE_STRSIZE].fetch[i];
316
317 WARN_ON(1); /* This should not happen */
318
319 return NULL;
320 }
321
322 /* Split symbol and offset. */
traceprobe_split_symbol_offset(char * symbol,long * offset)323 int traceprobe_split_symbol_offset(char *symbol, long *offset)
324 {
325 char *tmp;
326 int ret;
327
328 if (!offset)
329 return -EINVAL;
330
331 tmp = strpbrk(symbol, "+-");
332 if (tmp) {
333 ret = kstrtol(tmp, 0, offset);
334 if (ret)
335 return ret;
336 *tmp = '\0';
337 } else
338 *offset = 0;
339
340 return 0;
341 }
342
343 #define PARAM_MAX_STACK (THREAD_SIZE / sizeof(unsigned long))
344
parse_probe_vars(char * arg,const struct fetch_type * t,struct fetch_param * f,bool is_return,bool is_kprobe)345 static int parse_probe_vars(char *arg, const struct fetch_type *t,
346 struct fetch_param *f, bool is_return,
347 bool is_kprobe)
348 {
349 int ret = 0;
350 unsigned long param;
351
352 if (strcmp(arg, "retval") == 0) {
353 if (is_return)
354 f->fn = t->fetch[FETCH_MTD_retval];
355 else
356 ret = -EINVAL;
357 } else if (strncmp(arg, "stack", 5) == 0) {
358 if (arg[5] == '\0') {
359 if (strcmp(t->name, DEFAULT_FETCH_TYPE_STR))
360 return -EINVAL;
361
362 if (is_kprobe)
363 f->fn = fetch_kernel_stack_address;
364 else
365 f->fn = fetch_user_stack_address;
366 } else if (isdigit(arg[5])) {
367 ret = kstrtoul(arg + 5, 10, ¶m);
368 if (ret || (is_kprobe && param > PARAM_MAX_STACK))
369 ret = -EINVAL;
370 else {
371 f->fn = t->fetch[FETCH_MTD_stack];
372 f->data = (void *)param;
373 }
374 } else
375 ret = -EINVAL;
376 } else if (strcmp(arg, "comm") == 0) {
377 if (strcmp(t->name, "string") != 0 &&
378 strcmp(t->name, "string_size") != 0)
379 return -EINVAL;
380 f->fn = t->fetch[FETCH_MTD_comm];
381 } else
382 ret = -EINVAL;
383
384 return ret;
385 }
386
387 /* Recursive argument parser */
parse_probe_arg(char * arg,const struct fetch_type * t,struct fetch_param * f,bool is_return,bool is_kprobe,const struct fetch_type * ftbl)388 static int parse_probe_arg(char *arg, const struct fetch_type *t,
389 struct fetch_param *f, bool is_return, bool is_kprobe,
390 const struct fetch_type *ftbl)
391 {
392 unsigned long param;
393 long offset;
394 char *tmp;
395 int ret = 0;
396
397 switch (arg[0]) {
398 case '$':
399 ret = parse_probe_vars(arg + 1, t, f, is_return, is_kprobe);
400 break;
401
402 case '%': /* named register */
403 ret = regs_query_register_offset(arg + 1);
404 if (ret >= 0) {
405 f->fn = t->fetch[FETCH_MTD_reg];
406 f->data = (void *)(unsigned long)ret;
407 ret = 0;
408 }
409 break;
410
411 case '@': /* memory, file-offset or symbol */
412 if (isdigit(arg[1])) {
413 ret = kstrtoul(arg + 1, 0, ¶m);
414 if (ret)
415 break;
416
417 f->fn = t->fetch[FETCH_MTD_memory];
418 f->data = (void *)param;
419 } else if (arg[1] == '+') {
420 /* kprobes don't support file offsets */
421 if (is_kprobe)
422 return -EINVAL;
423
424 ret = kstrtol(arg + 2, 0, &offset);
425 if (ret)
426 break;
427
428 f->fn = t->fetch[FETCH_MTD_file_offset];
429 f->data = (void *)offset;
430 } else {
431 /* uprobes don't support symbols */
432 if (!is_kprobe)
433 return -EINVAL;
434
435 ret = traceprobe_split_symbol_offset(arg + 1, &offset);
436 if (ret)
437 break;
438
439 f->data = alloc_symbol_cache(arg + 1, offset);
440 if (f->data)
441 f->fn = t->fetch[FETCH_MTD_symbol];
442 }
443 break;
444
445 case '+': /* deref memory */
446 arg++; /* Skip '+', because kstrtol() rejects it. */
447 case '-':
448 tmp = strchr(arg, '(');
449 if (!tmp)
450 break;
451
452 *tmp = '\0';
453 ret = kstrtol(arg, 0, &offset);
454
455 if (ret)
456 break;
457
458 arg = tmp + 1;
459 tmp = strrchr(arg, ')');
460
461 if (tmp) {
462 struct deref_fetch_param *dprm;
463 const struct fetch_type *t2;
464
465 t2 = find_fetch_type(NULL, ftbl);
466 *tmp = '\0';
467 dprm = kzalloc(sizeof(struct deref_fetch_param), GFP_KERNEL);
468
469 if (!dprm)
470 return -ENOMEM;
471
472 dprm->offset = offset;
473 dprm->fetch = t->fetch[FETCH_MTD_memory];
474 dprm->fetch_size = get_fetch_size_function(t,
475 dprm->fetch, ftbl);
476 ret = parse_probe_arg(arg, t2, &dprm->orig, is_return,
477 is_kprobe, ftbl);
478 if (ret)
479 kfree(dprm);
480 else {
481 f->fn = t->fetch[FETCH_MTD_deref];
482 f->data = (void *)dprm;
483 }
484 }
485 break;
486 }
487 if (!ret && !f->fn) { /* Parsed, but do not find fetch method */
488 pr_info("%s type has no corresponding fetch method.\n", t->name);
489 ret = -EINVAL;
490 }
491
492 return ret;
493 }
494
495 #define BYTES_TO_BITS(nb) ((BITS_PER_LONG * (nb)) / sizeof(long))
496
497 /* Bitfield type needs to be parsed into a fetch function */
__parse_bitfield_probe_arg(const char * bf,const struct fetch_type * t,struct fetch_param * f)498 static int __parse_bitfield_probe_arg(const char *bf,
499 const struct fetch_type *t,
500 struct fetch_param *f)
501 {
502 struct bitfield_fetch_param *bprm;
503 unsigned long bw, bo;
504 char *tail;
505
506 if (*bf != 'b')
507 return 0;
508
509 bprm = kzalloc(sizeof(*bprm), GFP_KERNEL);
510 if (!bprm)
511 return -ENOMEM;
512
513 bprm->orig = *f;
514 f->fn = t->fetch[FETCH_MTD_bitfield];
515 f->data = (void *)bprm;
516 bw = simple_strtoul(bf + 1, &tail, 0); /* Use simple one */
517
518 if (bw == 0 || *tail != '@')
519 return -EINVAL;
520
521 bf = tail + 1;
522 bo = simple_strtoul(bf, &tail, 0);
523
524 if (tail == bf || *tail != '/')
525 return -EINVAL;
526
527 bprm->hi_shift = BYTES_TO_BITS(t->size) - (bw + bo);
528 bprm->low_shift = bprm->hi_shift + bo;
529
530 return (BYTES_TO_BITS(t->size) < (bw + bo)) ? -EINVAL : 0;
531 }
532
533 /* String length checking wrapper */
traceprobe_parse_probe_arg(char * arg,ssize_t * size,struct probe_arg * parg,bool is_return,bool is_kprobe,const struct fetch_type * ftbl)534 int traceprobe_parse_probe_arg(char *arg, ssize_t *size,
535 struct probe_arg *parg, bool is_return, bool is_kprobe,
536 const struct fetch_type *ftbl)
537 {
538 const char *t;
539 int ret;
540
541 if (strlen(arg) > MAX_ARGSTR_LEN) {
542 pr_info("Argument is too long.: %s\n", arg);
543 return -ENOSPC;
544 }
545 parg->comm = kstrdup(arg, GFP_KERNEL);
546 if (!parg->comm) {
547 pr_info("Failed to allocate memory for command '%s'.\n", arg);
548 return -ENOMEM;
549 }
550 t = strchr(parg->comm, ':');
551 if (t) {
552 arg[t - parg->comm] = '\0';
553 t++;
554 }
555 /*
556 * The default type of $comm should be "string", and it can't be
557 * dereferenced.
558 */
559 if (!t && strcmp(arg, "$comm") == 0)
560 t = "string";
561 parg->type = find_fetch_type(t, ftbl);
562 if (!parg->type) {
563 pr_info("Unsupported type: %s\n", t);
564 return -EINVAL;
565 }
566 parg->offset = *size;
567 *size += parg->type->size;
568 ret = parse_probe_arg(arg, parg->type, &parg->fetch, is_return,
569 is_kprobe, ftbl);
570
571 if (ret >= 0 && t != NULL)
572 ret = __parse_bitfield_probe_arg(t, parg->type, &parg->fetch);
573
574 if (ret >= 0) {
575 parg->fetch_size.fn = get_fetch_size_function(parg->type,
576 parg->fetch.fn,
577 ftbl);
578 parg->fetch_size.data = parg->fetch.data;
579 }
580
581 return ret;
582 }
583
584 /* Return 1 if name is reserved or already used by another argument */
traceprobe_conflict_field_name(const char * name,struct probe_arg * args,int narg)585 int traceprobe_conflict_field_name(const char *name,
586 struct probe_arg *args, int narg)
587 {
588 int i;
589
590 for (i = 0; i < ARRAY_SIZE(reserved_field_names); i++)
591 if (strcmp(reserved_field_names[i], name) == 0)
592 return 1;
593
594 for (i = 0; i < narg; i++)
595 if (strcmp(args[i].name, name) == 0)
596 return 1;
597
598 return 0;
599 }
600
traceprobe_update_arg(struct probe_arg * arg)601 void traceprobe_update_arg(struct probe_arg *arg)
602 {
603 if (CHECK_FETCH_FUNCS(bitfield, arg->fetch.fn))
604 update_bitfield_fetch_param(arg->fetch.data);
605 else if (CHECK_FETCH_FUNCS(deref, arg->fetch.fn))
606 update_deref_fetch_param(arg->fetch.data);
607 else if (CHECK_FETCH_FUNCS(symbol, arg->fetch.fn))
608 update_symbol_cache(arg->fetch.data);
609 }
610
traceprobe_free_probe_arg(struct probe_arg * arg)611 void traceprobe_free_probe_arg(struct probe_arg *arg)
612 {
613 if (CHECK_FETCH_FUNCS(bitfield, arg->fetch.fn))
614 free_bitfield_fetch_param(arg->fetch.data);
615 else if (CHECK_FETCH_FUNCS(deref, arg->fetch.fn))
616 free_deref_fetch_param(arg->fetch.data);
617 else if (CHECK_FETCH_FUNCS(symbol, arg->fetch.fn))
618 free_symbol_cache(arg->fetch.data);
619
620 kfree(arg->name);
621 kfree(arg->comm);
622 }
623
traceprobe_command(const char * buf,int (* createfn)(int,char **))624 int traceprobe_command(const char *buf, int (*createfn)(int, char **))
625 {
626 char **argv;
627 int argc, ret;
628
629 argc = 0;
630 ret = 0;
631 argv = argv_split(GFP_KERNEL, buf, &argc);
632 if (!argv)
633 return -ENOMEM;
634
635 if (argc)
636 ret = createfn(argc, argv);
637
638 argv_free(argv);
639
640 return ret;
641 }
642
643 #define WRITE_BUFSIZE 4096
644
traceprobe_probes_write(struct file * file,const char __user * buffer,size_t count,loff_t * ppos,int (* createfn)(int,char **))645 ssize_t traceprobe_probes_write(struct file *file, const char __user *buffer,
646 size_t count, loff_t *ppos,
647 int (*createfn)(int, char **))
648 {
649 char *kbuf, *buf, *tmp;
650 int ret = 0;
651 size_t done = 0;
652 size_t size;
653
654 kbuf = kmalloc(WRITE_BUFSIZE, GFP_KERNEL);
655 if (!kbuf)
656 return -ENOMEM;
657
658 while (done < count) {
659 size = count - done;
660
661 if (size >= WRITE_BUFSIZE)
662 size = WRITE_BUFSIZE - 1;
663
664 if (copy_from_user(kbuf, buffer + done, size)) {
665 ret = -EFAULT;
666 goto out;
667 }
668 kbuf[size] = '\0';
669 buf = kbuf;
670 do {
671 tmp = strchr(buf, '\n');
672 if (tmp) {
673 *tmp = '\0';
674 size = tmp - buf + 1;
675 } else {
676 size = strlen(buf);
677 if (done + size < count) {
678 if (buf != kbuf)
679 break;
680 /* This can accept WRITE_BUFSIZE - 2 ('\n' + '\0') */
681 pr_warn("Line length is too long: Should be less than %d\n",
682 WRITE_BUFSIZE - 2);
683 ret = -EINVAL;
684 goto out;
685 }
686 }
687 done += size;
688
689 /* Remove comments */
690 tmp = strchr(buf, '#');
691
692 if (tmp)
693 *tmp = '\0';
694
695 ret = traceprobe_command(buf, createfn);
696 if (ret)
697 goto out;
698 buf += size;
699
700 } while (done < count);
701 }
702 ret = done;
703
704 out:
705 kfree(kbuf);
706
707 return ret;
708 }
709
__set_print_fmt(struct trace_probe * tp,char * buf,int len,bool is_return)710 static int __set_print_fmt(struct trace_probe *tp, char *buf, int len,
711 bool is_return)
712 {
713 int i;
714 int pos = 0;
715
716 const char *fmt, *arg;
717
718 if (!is_return) {
719 fmt = "(%lx)";
720 arg = "REC->" FIELD_STRING_IP;
721 } else {
722 fmt = "(%lx <- %lx)";
723 arg = "REC->" FIELD_STRING_FUNC ", REC->" FIELD_STRING_RETIP;
724 }
725
726 /* When len=0, we just calculate the needed length */
727 #define LEN_OR_ZERO (len ? len - pos : 0)
728
729 pos += snprintf(buf + pos, LEN_OR_ZERO, "\"%s", fmt);
730
731 for (i = 0; i < tp->nr_args; i++) {
732 pos += snprintf(buf + pos, LEN_OR_ZERO, " %s=%s",
733 tp->args[i].name, tp->args[i].type->fmt);
734 }
735
736 pos += snprintf(buf + pos, LEN_OR_ZERO, "\", %s", arg);
737
738 for (i = 0; i < tp->nr_args; i++) {
739 if (strcmp(tp->args[i].type->name, "string") == 0)
740 pos += snprintf(buf + pos, LEN_OR_ZERO,
741 ", __get_str(%s)",
742 tp->args[i].name);
743 else
744 pos += snprintf(buf + pos, LEN_OR_ZERO, ", REC->%s",
745 tp->args[i].name);
746 }
747
748 #undef LEN_OR_ZERO
749
750 /* return the length of print_fmt */
751 return pos;
752 }
753
set_print_fmt(struct trace_probe * tp,bool is_return)754 int set_print_fmt(struct trace_probe *tp, bool is_return)
755 {
756 int len;
757 char *print_fmt;
758
759 /* First: called with 0 length to calculate the needed length */
760 len = __set_print_fmt(tp, NULL, 0, is_return);
761 print_fmt = kmalloc(len + 1, GFP_KERNEL);
762 if (!print_fmt)
763 return -ENOMEM;
764
765 /* Second: actually write the @print_fmt */
766 __set_print_fmt(tp, print_fmt, len + 1, is_return);
767 tp->call.print_fmt = print_fmt;
768
769 return 0;
770 }
771