Loading...
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
27const 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 in basic type function template */
39#define DEFINE_BASIC_PRINT_TYPE_FUNC(type, fmt) \
40int PRINT_TYPE_FUNC_NAME(type)(struct trace_seq *s, const char *name, \
41 void *data, void *ent) \
42{ \
43 trace_seq_printf(s, " %s=" fmt, name, *(type *)data); \
44 return !trace_seq_has_overflowed(s); \
45} \
46const char PRINT_TYPE_FMT_NAME(type)[] = fmt; \
47NOKPROBE_SYMBOL(PRINT_TYPE_FUNC_NAME(type));
48
49DEFINE_BASIC_PRINT_TYPE_FUNC(u8 , "0x%x")
50DEFINE_BASIC_PRINT_TYPE_FUNC(u16, "0x%x")
51DEFINE_BASIC_PRINT_TYPE_FUNC(u32, "0x%x")
52DEFINE_BASIC_PRINT_TYPE_FUNC(u64, "0x%Lx")
53DEFINE_BASIC_PRINT_TYPE_FUNC(s8, "%d")
54DEFINE_BASIC_PRINT_TYPE_FUNC(s16, "%d")
55DEFINE_BASIC_PRINT_TYPE_FUNC(s32, "%d")
56DEFINE_BASIC_PRINT_TYPE_FUNC(s64, "%Ld")
57
58/* Print type function for string type */
59int PRINT_TYPE_FUNC_NAME(string)(struct trace_seq *s, const char *name,
60 void *data, void *ent)
61{
62 int len = *(u32 *)data >> 16;
63
64 if (!len)
65 trace_seq_printf(s, " %s=(fault)", name);
66 else
67 trace_seq_printf(s, " %s=\"%s\"", name,
68 (const char *)get_loc_data(data, ent));
69 return !trace_seq_has_overflowed(s);
70}
71NOKPROBE_SYMBOL(PRINT_TYPE_FUNC_NAME(string));
72
73const char PRINT_TYPE_FMT_NAME(string)[] = "\\\"%s\\\"";
74
75#define CHECK_FETCH_FUNCS(method, fn) \
76 (((FETCH_FUNC_NAME(method, u8) == fn) || \
77 (FETCH_FUNC_NAME(method, u16) == fn) || \
78 (FETCH_FUNC_NAME(method, u32) == fn) || \
79 (FETCH_FUNC_NAME(method, u64) == fn) || \
80 (FETCH_FUNC_NAME(method, string) == fn) || \
81 (FETCH_FUNC_NAME(method, string_size) == fn)) \
82 && (fn != NULL))
83
84/* Data fetch function templates */
85#define DEFINE_FETCH_reg(type) \
86void FETCH_FUNC_NAME(reg, type)(struct pt_regs *regs, void *offset, void *dest) \
87{ \
88 *(type *)dest = (type)regs_get_register(regs, \
89 (unsigned int)((unsigned long)offset)); \
90} \
91NOKPROBE_SYMBOL(FETCH_FUNC_NAME(reg, type));
92DEFINE_BASIC_FETCH_FUNCS(reg)
93/* No string on the register */
94#define fetch_reg_string NULL
95#define fetch_reg_string_size NULL
96
97#define DEFINE_FETCH_retval(type) \
98void FETCH_FUNC_NAME(retval, type)(struct pt_regs *regs, \
99 void *dummy, void *dest) \
100{ \
101 *(type *)dest = (type)regs_return_value(regs); \
102} \
103NOKPROBE_SYMBOL(FETCH_FUNC_NAME(retval, type));
104DEFINE_BASIC_FETCH_FUNCS(retval)
105/* No string on the retval */
106#define fetch_retval_string NULL
107#define fetch_retval_string_size NULL
108
109/* Dereference memory access function */
110struct deref_fetch_param {
111 struct fetch_param orig;
112 long offset;
113 fetch_func_t fetch;
114 fetch_func_t fetch_size;
115};
116
117#define DEFINE_FETCH_deref(type) \
118void FETCH_FUNC_NAME(deref, type)(struct pt_regs *regs, \
119 void *data, void *dest) \
120{ \
121 struct deref_fetch_param *dprm = data; \
122 unsigned long addr; \
123 call_fetch(&dprm->orig, regs, &addr); \
124 if (addr) { \
125 addr += dprm->offset; \
126 dprm->fetch(regs, (void *)addr, dest); \
127 } else \
128 *(type *)dest = 0; \
129} \
130NOKPROBE_SYMBOL(FETCH_FUNC_NAME(deref, type));
131DEFINE_BASIC_FETCH_FUNCS(deref)
132DEFINE_FETCH_deref(string)
133
134void FETCH_FUNC_NAME(deref, string_size)(struct pt_regs *regs,
135 void *data, void *dest)
136{
137 struct deref_fetch_param *dprm = data;
138 unsigned long addr;
139
140 call_fetch(&dprm->orig, regs, &addr);
141 if (addr && dprm->fetch_size) {
142 addr += dprm->offset;
143 dprm->fetch_size(regs, (void *)addr, dest);
144 } else
145 *(string_size *)dest = 0;
146}
147NOKPROBE_SYMBOL(FETCH_FUNC_NAME(deref, string_size));
148
149static void update_deref_fetch_param(struct deref_fetch_param *data)
150{
151 if (CHECK_FETCH_FUNCS(deref, data->orig.fn))
152 update_deref_fetch_param(data->orig.data);
153 else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn))
154 update_symbol_cache(data->orig.data);
155}
156NOKPROBE_SYMBOL(update_deref_fetch_param);
157
158static void free_deref_fetch_param(struct deref_fetch_param *data)
159{
160 if (CHECK_FETCH_FUNCS(deref, data->orig.fn))
161 free_deref_fetch_param(data->orig.data);
162 else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn))
163 free_symbol_cache(data->orig.data);
164 kfree(data);
165}
166NOKPROBE_SYMBOL(free_deref_fetch_param);
167
168/* Bitfield fetch function */
169struct bitfield_fetch_param {
170 struct fetch_param orig;
171 unsigned char hi_shift;
172 unsigned char low_shift;
173};
174
175#define DEFINE_FETCH_bitfield(type) \
176void FETCH_FUNC_NAME(bitfield, type)(struct pt_regs *regs, \
177 void *data, void *dest) \
178{ \
179 struct bitfield_fetch_param *bprm = data; \
180 type buf = 0; \
181 call_fetch(&bprm->orig, regs, &buf); \
182 if (buf) { \
183 buf <<= bprm->hi_shift; \
184 buf >>= bprm->low_shift; \
185 } \
186 *(type *)dest = buf; \
187} \
188NOKPROBE_SYMBOL(FETCH_FUNC_NAME(bitfield, type));
189DEFINE_BASIC_FETCH_FUNCS(bitfield)
190#define fetch_bitfield_string NULL
191#define fetch_bitfield_string_size NULL
192
193static void
194update_bitfield_fetch_param(struct bitfield_fetch_param *data)
195{
196 /*
197 * Don't check the bitfield itself, because this must be the
198 * last fetch function.
199 */
200 if (CHECK_FETCH_FUNCS(deref, data->orig.fn))
201 update_deref_fetch_param(data->orig.data);
202 else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn))
203 update_symbol_cache(data->orig.data);
204}
205
206static void
207free_bitfield_fetch_param(struct bitfield_fetch_param *data)
208{
209 /*
210 * Don't check the bitfield itself, because this must be the
211 * last fetch function.
212 */
213 if (CHECK_FETCH_FUNCS(deref, data->orig.fn))
214 free_deref_fetch_param(data->orig.data);
215 else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn))
216 free_symbol_cache(data->orig.data);
217
218 kfree(data);
219}
220
221static const struct fetch_type *find_fetch_type(const char *type,
222 const struct fetch_type *ftbl)
223{
224 int i;
225
226 if (!type)
227 type = DEFAULT_FETCH_TYPE_STR;
228
229 /* Special case: bitfield */
230 if (*type == 'b') {
231 unsigned long bs;
232
233 type = strchr(type, '/');
234 if (!type)
235 goto fail;
236
237 type++;
238 if (kstrtoul(type, 0, &bs))
239 goto fail;
240
241 switch (bs) {
242 case 8:
243 return find_fetch_type("u8", ftbl);
244 case 16:
245 return find_fetch_type("u16", ftbl);
246 case 32:
247 return find_fetch_type("u32", ftbl);
248 case 64:
249 return find_fetch_type("u64", ftbl);
250 default:
251 goto fail;
252 }
253 }
254
255 for (i = 0; ftbl[i].name; i++) {
256 if (strcmp(type, ftbl[i].name) == 0)
257 return &ftbl[i];
258 }
259
260fail:
261 return NULL;
262}
263
264/* Special function : only accept unsigned long */
265static void fetch_kernel_stack_address(struct pt_regs *regs, void *dummy, void *dest)
266{
267 *(unsigned long *)dest = kernel_stack_pointer(regs);
268}
269NOKPROBE_SYMBOL(fetch_kernel_stack_address);
270
271static void fetch_user_stack_address(struct pt_regs *regs, void *dummy, void *dest)
272{
273 *(unsigned long *)dest = user_stack_pointer(regs);
274}
275NOKPROBE_SYMBOL(fetch_user_stack_address);
276
277static fetch_func_t get_fetch_size_function(const struct fetch_type *type,
278 fetch_func_t orig_fn,
279 const struct fetch_type *ftbl)
280{
281 int i;
282
283 if (type != &ftbl[FETCH_TYPE_STRING])
284 return NULL; /* Only string type needs size function */
285
286 for (i = 0; i < FETCH_MTD_END; i++)
287 if (type->fetch[i] == orig_fn)
288 return ftbl[FETCH_TYPE_STRSIZE].fetch[i];
289
290 WARN_ON(1); /* This should not happen */
291
292 return NULL;
293}
294
295/* Split symbol and offset. */
296int traceprobe_split_symbol_offset(char *symbol, unsigned long *offset)
297{
298 char *tmp;
299 int ret;
300
301 if (!offset)
302 return -EINVAL;
303
304 tmp = strchr(symbol, '+');
305 if (tmp) {
306 /* skip sign because kstrtoul doesn't accept '+' */
307 ret = kstrtoul(tmp + 1, 0, offset);
308 if (ret)
309 return ret;
310
311 *tmp = '\0';
312 } else
313 *offset = 0;
314
315 return 0;
316}
317
318#define PARAM_MAX_STACK (THREAD_SIZE / sizeof(unsigned long))
319
320static int parse_probe_vars(char *arg, const struct fetch_type *t,
321 struct fetch_param *f, bool is_return,
322 bool is_kprobe)
323{
324 int ret = 0;
325 unsigned long param;
326
327 if (strcmp(arg, "retval") == 0) {
328 if (is_return)
329 f->fn = t->fetch[FETCH_MTD_retval];
330 else
331 ret = -EINVAL;
332 } else if (strncmp(arg, "stack", 5) == 0) {
333 if (arg[5] == '\0') {
334 if (strcmp(t->name, DEFAULT_FETCH_TYPE_STR))
335 return -EINVAL;
336
337 if (is_kprobe)
338 f->fn = fetch_kernel_stack_address;
339 else
340 f->fn = fetch_user_stack_address;
341 } else if (isdigit(arg[5])) {
342 ret = kstrtoul(arg + 5, 10, ¶m);
343 if (ret || (is_kprobe && param > PARAM_MAX_STACK))
344 ret = -EINVAL;
345 else {
346 f->fn = t->fetch[FETCH_MTD_stack];
347 f->data = (void *)param;
348 }
349 } else
350 ret = -EINVAL;
351 } else
352 ret = -EINVAL;
353
354 return ret;
355}
356
357/* Recursive argument parser */
358static int parse_probe_arg(char *arg, const struct fetch_type *t,
359 struct fetch_param *f, bool is_return, bool is_kprobe,
360 const struct fetch_type *ftbl)
361{
362 unsigned long param;
363 long offset;
364 char *tmp;
365 int ret = 0;
366
367 switch (arg[0]) {
368 case '$':
369 ret = parse_probe_vars(arg + 1, t, f, is_return, is_kprobe);
370 break;
371
372 case '%': /* named register */
373 ret = regs_query_register_offset(arg + 1);
374 if (ret >= 0) {
375 f->fn = t->fetch[FETCH_MTD_reg];
376 f->data = (void *)(unsigned long)ret;
377 ret = 0;
378 }
379 break;
380
381 case '@': /* memory, file-offset or symbol */
382 if (isdigit(arg[1])) {
383 ret = kstrtoul(arg + 1, 0, ¶m);
384 if (ret)
385 break;
386
387 f->fn = t->fetch[FETCH_MTD_memory];
388 f->data = (void *)param;
389 } else if (arg[1] == '+') {
390 /* kprobes don't support file offsets */
391 if (is_kprobe)
392 return -EINVAL;
393
394 ret = kstrtol(arg + 2, 0, &offset);
395 if (ret)
396 break;
397
398 f->fn = t->fetch[FETCH_MTD_file_offset];
399 f->data = (void *)offset;
400 } else {
401 /* uprobes don't support symbols */
402 if (!is_kprobe)
403 return -EINVAL;
404
405 ret = traceprobe_split_symbol_offset(arg + 1, &offset);
406 if (ret)
407 break;
408
409 f->data = alloc_symbol_cache(arg + 1, offset);
410 if (f->data)
411 f->fn = t->fetch[FETCH_MTD_symbol];
412 }
413 break;
414
415 case '+': /* deref memory */
416 arg++; /* Skip '+', because kstrtol() rejects it. */
417 case '-':
418 tmp = strchr(arg, '(');
419 if (!tmp)
420 break;
421
422 *tmp = '\0';
423 ret = kstrtol(arg, 0, &offset);
424
425 if (ret)
426 break;
427
428 arg = tmp + 1;
429 tmp = strrchr(arg, ')');
430
431 if (tmp) {
432 struct deref_fetch_param *dprm;
433 const struct fetch_type *t2;
434
435 t2 = find_fetch_type(NULL, ftbl);
436 *tmp = '\0';
437 dprm = kzalloc(sizeof(struct deref_fetch_param), GFP_KERNEL);
438
439 if (!dprm)
440 return -ENOMEM;
441
442 dprm->offset = offset;
443 dprm->fetch = t->fetch[FETCH_MTD_memory];
444 dprm->fetch_size = get_fetch_size_function(t,
445 dprm->fetch, ftbl);
446 ret = parse_probe_arg(arg, t2, &dprm->orig, is_return,
447 is_kprobe, ftbl);
448 if (ret)
449 kfree(dprm);
450 else {
451 f->fn = t->fetch[FETCH_MTD_deref];
452 f->data = (void *)dprm;
453 }
454 }
455 break;
456 }
457 if (!ret && !f->fn) { /* Parsed, but do not find fetch method */
458 pr_info("%s type has no corresponding fetch method.\n", t->name);
459 ret = -EINVAL;
460 }
461
462 return ret;
463}
464
465#define BYTES_TO_BITS(nb) ((BITS_PER_LONG * (nb)) / sizeof(long))
466
467/* Bitfield type needs to be parsed into a fetch function */
468static int __parse_bitfield_probe_arg(const char *bf,
469 const struct fetch_type *t,
470 struct fetch_param *f)
471{
472 struct bitfield_fetch_param *bprm;
473 unsigned long bw, bo;
474 char *tail;
475
476 if (*bf != 'b')
477 return 0;
478
479 bprm = kzalloc(sizeof(*bprm), GFP_KERNEL);
480 if (!bprm)
481 return -ENOMEM;
482
483 bprm->orig = *f;
484 f->fn = t->fetch[FETCH_MTD_bitfield];
485 f->data = (void *)bprm;
486 bw = simple_strtoul(bf + 1, &tail, 0); /* Use simple one */
487
488 if (bw == 0 || *tail != '@')
489 return -EINVAL;
490
491 bf = tail + 1;
492 bo = simple_strtoul(bf, &tail, 0);
493
494 if (tail == bf || *tail != '/')
495 return -EINVAL;
496
497 bprm->hi_shift = BYTES_TO_BITS(t->size) - (bw + bo);
498 bprm->low_shift = bprm->hi_shift + bo;
499
500 return (BYTES_TO_BITS(t->size) < (bw + bo)) ? -EINVAL : 0;
501}
502
503/* String length checking wrapper */
504int traceprobe_parse_probe_arg(char *arg, ssize_t *size,
505 struct probe_arg *parg, bool is_return, bool is_kprobe,
506 const struct fetch_type *ftbl)
507{
508 const char *t;
509 int ret;
510
511 if (strlen(arg) > MAX_ARGSTR_LEN) {
512 pr_info("Argument is too long.: %s\n", arg);
513 return -ENOSPC;
514 }
515 parg->comm = kstrdup(arg, GFP_KERNEL);
516 if (!parg->comm) {
517 pr_info("Failed to allocate memory for command '%s'.\n", arg);
518 return -ENOMEM;
519 }
520 t = strchr(parg->comm, ':');
521 if (t) {
522 arg[t - parg->comm] = '\0';
523 t++;
524 }
525 parg->type = find_fetch_type(t, ftbl);
526 if (!parg->type) {
527 pr_info("Unsupported type: %s\n", t);
528 return -EINVAL;
529 }
530 parg->offset = *size;
531 *size += parg->type->size;
532 ret = parse_probe_arg(arg, parg->type, &parg->fetch, is_return,
533 is_kprobe, ftbl);
534
535 if (ret >= 0 && t != NULL)
536 ret = __parse_bitfield_probe_arg(t, parg->type, &parg->fetch);
537
538 if (ret >= 0) {
539 parg->fetch_size.fn = get_fetch_size_function(parg->type,
540 parg->fetch.fn,
541 ftbl);
542 parg->fetch_size.data = parg->fetch.data;
543 }
544
545 return ret;
546}
547
548/* Return 1 if name is reserved or already used by another argument */
549int traceprobe_conflict_field_name(const char *name,
550 struct probe_arg *args, int narg)
551{
552 int i;
553
554 for (i = 0; i < ARRAY_SIZE(reserved_field_names); i++)
555 if (strcmp(reserved_field_names[i], name) == 0)
556 return 1;
557
558 for (i = 0; i < narg; i++)
559 if (strcmp(args[i].name, name) == 0)
560 return 1;
561
562 return 0;
563}
564
565void traceprobe_update_arg(struct probe_arg *arg)
566{
567 if (CHECK_FETCH_FUNCS(bitfield, arg->fetch.fn))
568 update_bitfield_fetch_param(arg->fetch.data);
569 else if (CHECK_FETCH_FUNCS(deref, arg->fetch.fn))
570 update_deref_fetch_param(arg->fetch.data);
571 else if (CHECK_FETCH_FUNCS(symbol, arg->fetch.fn))
572 update_symbol_cache(arg->fetch.data);
573}
574
575void traceprobe_free_probe_arg(struct probe_arg *arg)
576{
577 if (CHECK_FETCH_FUNCS(bitfield, arg->fetch.fn))
578 free_bitfield_fetch_param(arg->fetch.data);
579 else if (CHECK_FETCH_FUNCS(deref, arg->fetch.fn))
580 free_deref_fetch_param(arg->fetch.data);
581 else if (CHECK_FETCH_FUNCS(symbol, arg->fetch.fn))
582 free_symbol_cache(arg->fetch.data);
583
584 kfree(arg->name);
585 kfree(arg->comm);
586}
587
588int traceprobe_command(const char *buf, int (*createfn)(int, char **))
589{
590 char **argv;
591 int argc, ret;
592
593 argc = 0;
594 ret = 0;
595 argv = argv_split(GFP_KERNEL, buf, &argc);
596 if (!argv)
597 return -ENOMEM;
598
599 if (argc)
600 ret = createfn(argc, argv);
601
602 argv_free(argv);
603
604 return ret;
605}
606
607#define WRITE_BUFSIZE 4096
608
609ssize_t traceprobe_probes_write(struct file *file, const char __user *buffer,
610 size_t count, loff_t *ppos,
611 int (*createfn)(int, char **))
612{
613 char *kbuf, *tmp;
614 int ret = 0;
615 size_t done = 0;
616 size_t size;
617
618 kbuf = kmalloc(WRITE_BUFSIZE, GFP_KERNEL);
619 if (!kbuf)
620 return -ENOMEM;
621
622 while (done < count) {
623 size = count - done;
624
625 if (size >= WRITE_BUFSIZE)
626 size = WRITE_BUFSIZE - 1;
627
628 if (copy_from_user(kbuf, buffer + done, size)) {
629 ret = -EFAULT;
630 goto out;
631 }
632 kbuf[size] = '\0';
633 tmp = strchr(kbuf, '\n');
634
635 if (tmp) {
636 *tmp = '\0';
637 size = tmp - kbuf + 1;
638 } else if (done + size < count) {
639 pr_warn("Line length is too long: Should be less than %d\n",
640 WRITE_BUFSIZE);
641 ret = -EINVAL;
642 goto out;
643 }
644 done += size;
645 /* Remove comments */
646 tmp = strchr(kbuf, '#');
647
648 if (tmp)
649 *tmp = '\0';
650
651 ret = traceprobe_command(kbuf, createfn);
652 if (ret)
653 goto out;
654 }
655 ret = done;
656
657out:
658 kfree(kbuf);
659
660 return ret;
661}
662
663static int __set_print_fmt(struct trace_probe *tp, char *buf, int len,
664 bool is_return)
665{
666 int i;
667 int pos = 0;
668
669 const char *fmt, *arg;
670
671 if (!is_return) {
672 fmt = "(%lx)";
673 arg = "REC->" FIELD_STRING_IP;
674 } else {
675 fmt = "(%lx <- %lx)";
676 arg = "REC->" FIELD_STRING_FUNC ", REC->" FIELD_STRING_RETIP;
677 }
678
679 /* When len=0, we just calculate the needed length */
680#define LEN_OR_ZERO (len ? len - pos : 0)
681
682 pos += snprintf(buf + pos, LEN_OR_ZERO, "\"%s", fmt);
683
684 for (i = 0; i < tp->nr_args; i++) {
685 pos += snprintf(buf + pos, LEN_OR_ZERO, " %s=%s",
686 tp->args[i].name, tp->args[i].type->fmt);
687 }
688
689 pos += snprintf(buf + pos, LEN_OR_ZERO, "\", %s", arg);
690
691 for (i = 0; i < tp->nr_args; i++) {
692 if (strcmp(tp->args[i].type->name, "string") == 0)
693 pos += snprintf(buf + pos, LEN_OR_ZERO,
694 ", __get_str(%s)",
695 tp->args[i].name);
696 else
697 pos += snprintf(buf + pos, LEN_OR_ZERO, ", REC->%s",
698 tp->args[i].name);
699 }
700
701#undef LEN_OR_ZERO
702
703 /* return the length of print_fmt */
704 return pos;
705}
706
707int set_print_fmt(struct trace_probe *tp, bool is_return)
708{
709 int len;
710 char *print_fmt;
711
712 /* First: called with 0 length to calculate the needed length */
713 len = __set_print_fmt(tp, NULL, 0, is_return);
714 print_fmt = kmalloc(len + 1, GFP_KERNEL);
715 if (!print_fmt)
716 return -ENOMEM;
717
718 /* Second: actually write the @print_fmt */
719 __set_print_fmt(tp, print_fmt, len + 1, is_return);
720 tp->call.print_fmt = print_fmt;
721
722 return 0;
723}
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Common code for probe-based Dynamic events.
4 *
5 * This code was copied from kernel/trace/trace_kprobe.c written by
6 * Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
7 *
8 * Updates to make this generic:
9 * Copyright (C) IBM Corporation, 2010-2011
10 * Author: Srikar Dronamraju
11 */
12#define pr_fmt(fmt) "trace_probe: " fmt
13
14#include <linux/bpf.h>
15#include "trace_btf.h"
16
17#include "trace_probe.h"
18
19#undef C
20#define C(a, b) b
21
22static const char *trace_probe_err_text[] = { ERRORS };
23
24static const char *reserved_field_names[] = {
25 "common_type",
26 "common_flags",
27 "common_preempt_count",
28 "common_pid",
29 "common_tgid",
30 FIELD_STRING_IP,
31 FIELD_STRING_RETIP,
32 FIELD_STRING_FUNC,
33};
34
35/* Printing in basic type function template */
36#define DEFINE_BASIC_PRINT_TYPE_FUNC(tname, type, fmt) \
37int PRINT_TYPE_FUNC_NAME(tname)(struct trace_seq *s, void *data, void *ent)\
38{ \
39 trace_seq_printf(s, fmt, *(type *)data); \
40 return !trace_seq_has_overflowed(s); \
41} \
42const char PRINT_TYPE_FMT_NAME(tname)[] = fmt;
43
44DEFINE_BASIC_PRINT_TYPE_FUNC(u8, u8, "%u")
45DEFINE_BASIC_PRINT_TYPE_FUNC(u16, u16, "%u")
46DEFINE_BASIC_PRINT_TYPE_FUNC(u32, u32, "%u")
47DEFINE_BASIC_PRINT_TYPE_FUNC(u64, u64, "%Lu")
48DEFINE_BASIC_PRINT_TYPE_FUNC(s8, s8, "%d")
49DEFINE_BASIC_PRINT_TYPE_FUNC(s16, s16, "%d")
50DEFINE_BASIC_PRINT_TYPE_FUNC(s32, s32, "%d")
51DEFINE_BASIC_PRINT_TYPE_FUNC(s64, s64, "%Ld")
52DEFINE_BASIC_PRINT_TYPE_FUNC(x8, u8, "0x%x")
53DEFINE_BASIC_PRINT_TYPE_FUNC(x16, u16, "0x%x")
54DEFINE_BASIC_PRINT_TYPE_FUNC(x32, u32, "0x%x")
55DEFINE_BASIC_PRINT_TYPE_FUNC(x64, u64, "0x%Lx")
56DEFINE_BASIC_PRINT_TYPE_FUNC(char, u8, "'%c'")
57
58int PRINT_TYPE_FUNC_NAME(symbol)(struct trace_seq *s, void *data, void *ent)
59{
60 trace_seq_printf(s, "%pS", (void *)*(unsigned long *)data);
61 return !trace_seq_has_overflowed(s);
62}
63const char PRINT_TYPE_FMT_NAME(symbol)[] = "%pS";
64
65/* Print type function for string type */
66int PRINT_TYPE_FUNC_NAME(string)(struct trace_seq *s, void *data, void *ent)
67{
68 int len = *(u32 *)data >> 16;
69
70 if (!len)
71 trace_seq_puts(s, FAULT_STRING);
72 else
73 trace_seq_printf(s, "\"%s\"",
74 (const char *)get_loc_data(data, ent));
75 return !trace_seq_has_overflowed(s);
76}
77
78const char PRINT_TYPE_FMT_NAME(string)[] = "\\\"%s\\\"";
79
80/* Fetch type information table */
81static const struct fetch_type probe_fetch_types[] = {
82 /* Special types */
83 __ASSIGN_FETCH_TYPE("string", string, string, sizeof(u32), 1, 1,
84 "__data_loc char[]"),
85 __ASSIGN_FETCH_TYPE("ustring", string, string, sizeof(u32), 1, 1,
86 "__data_loc char[]"),
87 __ASSIGN_FETCH_TYPE("symstr", string, string, sizeof(u32), 1, 1,
88 "__data_loc char[]"),
89 /* Basic types */
90 ASSIGN_FETCH_TYPE(u8, u8, 0),
91 ASSIGN_FETCH_TYPE(u16, u16, 0),
92 ASSIGN_FETCH_TYPE(u32, u32, 0),
93 ASSIGN_FETCH_TYPE(u64, u64, 0),
94 ASSIGN_FETCH_TYPE(s8, u8, 1),
95 ASSIGN_FETCH_TYPE(s16, u16, 1),
96 ASSIGN_FETCH_TYPE(s32, u32, 1),
97 ASSIGN_FETCH_TYPE(s64, u64, 1),
98 ASSIGN_FETCH_TYPE_ALIAS(x8, u8, u8, 0),
99 ASSIGN_FETCH_TYPE_ALIAS(x16, u16, u16, 0),
100 ASSIGN_FETCH_TYPE_ALIAS(x32, u32, u32, 0),
101 ASSIGN_FETCH_TYPE_ALIAS(x64, u64, u64, 0),
102 ASSIGN_FETCH_TYPE_ALIAS(char, u8, u8, 0),
103 ASSIGN_FETCH_TYPE_ALIAS(symbol, ADDR_FETCH_TYPE, ADDR_FETCH_TYPE, 0),
104
105 ASSIGN_FETCH_TYPE_END
106};
107
108static const struct fetch_type *find_fetch_type(const char *type, unsigned long flags)
109{
110 int i;
111
112 /* Reject the symbol/symstr for uprobes */
113 if (type && (flags & TPARG_FL_USER) &&
114 (!strcmp(type, "symbol") || !strcmp(type, "symstr")))
115 return NULL;
116
117 if (!type)
118 type = DEFAULT_FETCH_TYPE_STR;
119
120 /* Special case: bitfield */
121 if (*type == 'b') {
122 unsigned long bs;
123
124 type = strchr(type, '/');
125 if (!type)
126 goto fail;
127
128 type++;
129 if (kstrtoul(type, 0, &bs))
130 goto fail;
131
132 switch (bs) {
133 case 8:
134 return find_fetch_type("u8", flags);
135 case 16:
136 return find_fetch_type("u16", flags);
137 case 32:
138 return find_fetch_type("u32", flags);
139 case 64:
140 return find_fetch_type("u64", flags);
141 default:
142 goto fail;
143 }
144 }
145
146 for (i = 0; probe_fetch_types[i].name; i++) {
147 if (strcmp(type, probe_fetch_types[i].name) == 0)
148 return &probe_fetch_types[i];
149 }
150
151fail:
152 return NULL;
153}
154
155static struct trace_probe_log trace_probe_log;
156
157void trace_probe_log_init(const char *subsystem, int argc, const char **argv)
158{
159 trace_probe_log.subsystem = subsystem;
160 trace_probe_log.argc = argc;
161 trace_probe_log.argv = argv;
162 trace_probe_log.index = 0;
163}
164
165void trace_probe_log_clear(void)
166{
167 memset(&trace_probe_log, 0, sizeof(trace_probe_log));
168}
169
170void trace_probe_log_set_index(int index)
171{
172 trace_probe_log.index = index;
173}
174
175void __trace_probe_log_err(int offset, int err_type)
176{
177 char *command, *p;
178 int i, len = 0, pos = 0;
179
180 if (!trace_probe_log.argv)
181 return;
182
183 /* Recalculate the length and allocate buffer */
184 for (i = 0; i < trace_probe_log.argc; i++) {
185 if (i == trace_probe_log.index)
186 pos = len;
187 len += strlen(trace_probe_log.argv[i]) + 1;
188 }
189 command = kzalloc(len, GFP_KERNEL);
190 if (!command)
191 return;
192
193 if (trace_probe_log.index >= trace_probe_log.argc) {
194 /**
195 * Set the error position is next to the last arg + space.
196 * Note that len includes the terminal null and the cursor
197 * appears at pos + 1.
198 */
199 pos = len;
200 offset = 0;
201 }
202
203 /* And make a command string from argv array */
204 p = command;
205 for (i = 0; i < trace_probe_log.argc; i++) {
206 len = strlen(trace_probe_log.argv[i]);
207 strcpy(p, trace_probe_log.argv[i]);
208 p[len] = ' ';
209 p += len + 1;
210 }
211 *(p - 1) = '\0';
212
213 tracing_log_err(NULL, trace_probe_log.subsystem, command,
214 trace_probe_err_text, err_type, pos + offset);
215
216 kfree(command);
217}
218
219/* Split symbol and offset. */
220int traceprobe_split_symbol_offset(char *symbol, long *offset)
221{
222 char *tmp;
223 int ret;
224
225 if (!offset)
226 return -EINVAL;
227
228 tmp = strpbrk(symbol, "+-");
229 if (tmp) {
230 ret = kstrtol(tmp, 0, offset);
231 if (ret)
232 return ret;
233 *tmp = '\0';
234 } else
235 *offset = 0;
236
237 return 0;
238}
239
240/* @buf must has MAX_EVENT_NAME_LEN size */
241int traceprobe_parse_event_name(const char **pevent, const char **pgroup,
242 char *buf, int offset)
243{
244 const char *slash, *event = *pevent;
245 int len;
246
247 slash = strchr(event, '/');
248 if (!slash)
249 slash = strchr(event, '.');
250
251 if (slash) {
252 if (slash == event) {
253 trace_probe_log_err(offset, NO_GROUP_NAME);
254 return -EINVAL;
255 }
256 if (slash - event + 1 > MAX_EVENT_NAME_LEN) {
257 trace_probe_log_err(offset, GROUP_TOO_LONG);
258 return -EINVAL;
259 }
260 strscpy(buf, event, slash - event + 1);
261 if (!is_good_system_name(buf)) {
262 trace_probe_log_err(offset, BAD_GROUP_NAME);
263 return -EINVAL;
264 }
265 *pgroup = buf;
266 *pevent = slash + 1;
267 offset += slash - event + 1;
268 event = *pevent;
269 }
270 len = strlen(event);
271 if (len == 0) {
272 if (slash) {
273 *pevent = NULL;
274 return 0;
275 }
276 trace_probe_log_err(offset, NO_EVENT_NAME);
277 return -EINVAL;
278 } else if (len > MAX_EVENT_NAME_LEN) {
279 trace_probe_log_err(offset, EVENT_TOO_LONG);
280 return -EINVAL;
281 }
282 if (!is_good_name(event)) {
283 trace_probe_log_err(offset, BAD_EVENT_NAME);
284 return -EINVAL;
285 }
286 return 0;
287}
288
289static int parse_trace_event_arg(char *arg, struct fetch_insn *code,
290 struct traceprobe_parse_context *ctx)
291{
292 struct ftrace_event_field *field;
293 struct list_head *head;
294
295 head = trace_get_fields(ctx->event);
296 list_for_each_entry(field, head, link) {
297 if (!strcmp(arg, field->name)) {
298 code->op = FETCH_OP_TP_ARG;
299 code->data = field;
300 return 0;
301 }
302 }
303 return -ENOENT;
304}
305
306#ifdef CONFIG_PROBE_EVENTS_BTF_ARGS
307
308static u32 btf_type_int(const struct btf_type *t)
309{
310 return *(u32 *)(t + 1);
311}
312
313static bool btf_type_is_char_ptr(struct btf *btf, const struct btf_type *type)
314{
315 const struct btf_type *real_type;
316 u32 intdata;
317 s32 tid;
318
319 real_type = btf_type_skip_modifiers(btf, type->type, &tid);
320 if (!real_type)
321 return false;
322
323 if (BTF_INFO_KIND(real_type->info) != BTF_KIND_INT)
324 return false;
325
326 intdata = btf_type_int(real_type);
327 return !(BTF_INT_ENCODING(intdata) & BTF_INT_SIGNED)
328 && BTF_INT_BITS(intdata) == 8;
329}
330
331static bool btf_type_is_char_array(struct btf *btf, const struct btf_type *type)
332{
333 const struct btf_type *real_type;
334 const struct btf_array *array;
335 u32 intdata;
336 s32 tid;
337
338 if (BTF_INFO_KIND(type->info) != BTF_KIND_ARRAY)
339 return false;
340
341 array = (const struct btf_array *)(type + 1);
342
343 real_type = btf_type_skip_modifiers(btf, array->type, &tid);
344
345 intdata = btf_type_int(real_type);
346 return !(BTF_INT_ENCODING(intdata) & BTF_INT_SIGNED)
347 && BTF_INT_BITS(intdata) == 8;
348}
349
350static int check_prepare_btf_string_fetch(char *typename,
351 struct fetch_insn **pcode,
352 struct traceprobe_parse_context *ctx)
353{
354 struct btf *btf = ctx->btf;
355
356 if (!btf || !ctx->last_type)
357 return 0;
358
359 /* char [] does not need any change. */
360 if (btf_type_is_char_array(btf, ctx->last_type))
361 return 0;
362
363 /* char * requires dereference the pointer. */
364 if (btf_type_is_char_ptr(btf, ctx->last_type)) {
365 struct fetch_insn *code = *pcode + 1;
366
367 if (code->op == FETCH_OP_END) {
368 trace_probe_log_err(ctx->offset, TOO_MANY_OPS);
369 return -E2BIG;
370 }
371 if (typename[0] == 'u')
372 code->op = FETCH_OP_UDEREF;
373 else
374 code->op = FETCH_OP_DEREF;
375 code->offset = 0;
376 *pcode = code;
377 return 0;
378 }
379 /* Other types are not available for string */
380 trace_probe_log_err(ctx->offset, BAD_TYPE4STR);
381 return -EINVAL;
382}
383
384static const char *fetch_type_from_btf_type(struct btf *btf,
385 const struct btf_type *type,
386 struct traceprobe_parse_context *ctx)
387{
388 u32 intdata;
389
390 /* TODO: const char * could be converted as a string */
391 switch (BTF_INFO_KIND(type->info)) {
392 case BTF_KIND_ENUM:
393 /* enum is "int", so convert to "s32" */
394 return "s32";
395 case BTF_KIND_ENUM64:
396 return "s64";
397 case BTF_KIND_PTR:
398 /* pointer will be converted to "x??" */
399 if (IS_ENABLED(CONFIG_64BIT))
400 return "x64";
401 else
402 return "x32";
403 case BTF_KIND_INT:
404 intdata = btf_type_int(type);
405 if (BTF_INT_ENCODING(intdata) & BTF_INT_SIGNED) {
406 switch (BTF_INT_BITS(intdata)) {
407 case 8:
408 return "s8";
409 case 16:
410 return "s16";
411 case 32:
412 return "s32";
413 case 64:
414 return "s64";
415 }
416 } else { /* unsigned */
417 switch (BTF_INT_BITS(intdata)) {
418 case 8:
419 return "u8";
420 case 16:
421 return "u16";
422 case 32:
423 return "u32";
424 case 64:
425 return "u64";
426 }
427 /* bitfield, size is encoded in the type */
428 ctx->last_bitsize = BTF_INT_BITS(intdata);
429 ctx->last_bitoffs += BTF_INT_OFFSET(intdata);
430 return "u64";
431 }
432 }
433 /* TODO: support other types */
434
435 return NULL;
436}
437
438static int query_btf_context(struct traceprobe_parse_context *ctx)
439{
440 const struct btf_param *param;
441 const struct btf_type *type;
442 struct btf *btf;
443 s32 nr;
444
445 if (ctx->btf)
446 return 0;
447
448 if (!ctx->funcname)
449 return -EINVAL;
450
451 type = btf_find_func_proto(ctx->funcname, &btf);
452 if (!type)
453 return -ENOENT;
454
455 ctx->btf = btf;
456 ctx->proto = type;
457
458 /* ctx->params is optional, since func(void) will not have params. */
459 nr = 0;
460 param = btf_get_func_param(type, &nr);
461 if (!IS_ERR_OR_NULL(param)) {
462 /* Hide the first 'data' argument of tracepoint */
463 if (ctx->flags & TPARG_FL_TPOINT) {
464 nr--;
465 param++;
466 }
467 }
468
469 if (nr > 0) {
470 ctx->nr_params = nr;
471 ctx->params = param;
472 } else {
473 ctx->nr_params = 0;
474 ctx->params = NULL;
475 }
476
477 return 0;
478}
479
480static void clear_btf_context(struct traceprobe_parse_context *ctx)
481{
482 if (ctx->btf) {
483 btf_put(ctx->btf);
484 ctx->btf = NULL;
485 ctx->proto = NULL;
486 ctx->params = NULL;
487 ctx->nr_params = 0;
488 }
489}
490
491/* Return 1 if the field separater is arrow operator ('->') */
492static int split_next_field(char *varname, char **next_field,
493 struct traceprobe_parse_context *ctx)
494{
495 char *field;
496 int ret = 0;
497
498 field = strpbrk(varname, ".-");
499 if (field) {
500 if (field[0] == '-' && field[1] == '>') {
501 field[0] = '\0';
502 field += 2;
503 ret = 1;
504 } else if (field[0] == '.') {
505 field[0] = '\0';
506 field += 1;
507 } else {
508 trace_probe_log_err(ctx->offset + field - varname, BAD_HYPHEN);
509 return -EINVAL;
510 }
511 *next_field = field;
512 }
513
514 return ret;
515}
516
517/*
518 * Parse the field of data structure. The @type must be a pointer type
519 * pointing the target data structure type.
520 */
521static int parse_btf_field(char *fieldname, const struct btf_type *type,
522 struct fetch_insn **pcode, struct fetch_insn *end,
523 struct traceprobe_parse_context *ctx)
524{
525 struct fetch_insn *code = *pcode;
526 const struct btf_member *field;
527 u32 bitoffs, anon_offs;
528 char *next;
529 int is_ptr;
530 s32 tid;
531
532 do {
533 /* Outer loop for solving arrow operator ('->') */
534 if (BTF_INFO_KIND(type->info) != BTF_KIND_PTR) {
535 trace_probe_log_err(ctx->offset, NO_PTR_STRCT);
536 return -EINVAL;
537 }
538 /* Convert a struct pointer type to a struct type */
539 type = btf_type_skip_modifiers(ctx->btf, type->type, &tid);
540 if (!type) {
541 trace_probe_log_err(ctx->offset, BAD_BTF_TID);
542 return -EINVAL;
543 }
544
545 bitoffs = 0;
546 do {
547 /* Inner loop for solving dot operator ('.') */
548 next = NULL;
549 is_ptr = split_next_field(fieldname, &next, ctx);
550 if (is_ptr < 0)
551 return is_ptr;
552
553 anon_offs = 0;
554 field = btf_find_struct_member(ctx->btf, type, fieldname,
555 &anon_offs);
556 if (!field) {
557 trace_probe_log_err(ctx->offset, NO_BTF_FIELD);
558 return -ENOENT;
559 }
560 /* Add anonymous structure/union offset */
561 bitoffs += anon_offs;
562
563 /* Accumulate the bit-offsets of the dot-connected fields */
564 if (btf_type_kflag(type)) {
565 bitoffs += BTF_MEMBER_BIT_OFFSET(field->offset);
566 ctx->last_bitsize = BTF_MEMBER_BITFIELD_SIZE(field->offset);
567 } else {
568 bitoffs += field->offset;
569 ctx->last_bitsize = 0;
570 }
571
572 type = btf_type_skip_modifiers(ctx->btf, field->type, &tid);
573 if (!type) {
574 trace_probe_log_err(ctx->offset, BAD_BTF_TID);
575 return -EINVAL;
576 }
577
578 ctx->offset += next - fieldname;
579 fieldname = next;
580 } while (!is_ptr && fieldname);
581
582 if (++code == end) {
583 trace_probe_log_err(ctx->offset, TOO_MANY_OPS);
584 return -EINVAL;
585 }
586 code->op = FETCH_OP_DEREF; /* TODO: user deref support */
587 code->offset = bitoffs / 8;
588 *pcode = code;
589
590 ctx->last_bitoffs = bitoffs % 8;
591 ctx->last_type = type;
592 } while (fieldname);
593
594 return 0;
595}
596
597static int parse_btf_arg(char *varname,
598 struct fetch_insn **pcode, struct fetch_insn *end,
599 struct traceprobe_parse_context *ctx)
600{
601 struct fetch_insn *code = *pcode;
602 const struct btf_param *params;
603 const struct btf_type *type;
604 char *field = NULL;
605 int i, is_ptr, ret;
606 u32 tid;
607
608 if (WARN_ON_ONCE(!ctx->funcname))
609 return -EINVAL;
610
611 is_ptr = split_next_field(varname, &field, ctx);
612 if (is_ptr < 0)
613 return is_ptr;
614 if (!is_ptr && field) {
615 /* dot-connected field on an argument is not supported. */
616 trace_probe_log_err(ctx->offset + field - varname,
617 NOSUP_DAT_ARG);
618 return -EOPNOTSUPP;
619 }
620
621 if (ctx->flags & TPARG_FL_RETURN) {
622 if (strcmp(varname, "$retval") != 0) {
623 trace_probe_log_err(ctx->offset, NO_BTFARG);
624 return -ENOENT;
625 }
626 code->op = FETCH_OP_RETVAL;
627 /* Check whether the function return type is not void */
628 if (query_btf_context(ctx) == 0) {
629 if (ctx->proto->type == 0) {
630 trace_probe_log_err(ctx->offset, NO_RETVAL);
631 return -ENOENT;
632 }
633 tid = ctx->proto->type;
634 goto found;
635 }
636 if (field) {
637 trace_probe_log_err(ctx->offset + field - varname,
638 NO_BTF_ENTRY);
639 return -ENOENT;
640 }
641 return 0;
642 }
643
644 if (!ctx->btf) {
645 ret = query_btf_context(ctx);
646 if (ret < 0 || ctx->nr_params == 0) {
647 trace_probe_log_err(ctx->offset, NO_BTF_ENTRY);
648 return PTR_ERR(params);
649 }
650 }
651 params = ctx->params;
652
653 for (i = 0; i < ctx->nr_params; i++) {
654 const char *name = btf_name_by_offset(ctx->btf, params[i].name_off);
655
656 if (name && !strcmp(name, varname)) {
657 code->op = FETCH_OP_ARG;
658 if (ctx->flags & TPARG_FL_TPOINT)
659 code->param = i + 1;
660 else
661 code->param = i;
662 tid = params[i].type;
663 goto found;
664 }
665 }
666 trace_probe_log_err(ctx->offset, NO_BTFARG);
667 return -ENOENT;
668
669found:
670 type = btf_type_skip_modifiers(ctx->btf, tid, &tid);
671 if (!type) {
672 trace_probe_log_err(ctx->offset, BAD_BTF_TID);
673 return -EINVAL;
674 }
675 /* Initialize the last type information */
676 ctx->last_type = type;
677 ctx->last_bitoffs = 0;
678 ctx->last_bitsize = 0;
679 if (field) {
680 ctx->offset += field - varname;
681 return parse_btf_field(field, type, pcode, end, ctx);
682 }
683 return 0;
684}
685
686static const struct fetch_type *find_fetch_type_from_btf_type(
687 struct traceprobe_parse_context *ctx)
688{
689 struct btf *btf = ctx->btf;
690 const char *typestr = NULL;
691
692 if (btf && ctx->last_type)
693 typestr = fetch_type_from_btf_type(btf, ctx->last_type, ctx);
694
695 return find_fetch_type(typestr, ctx->flags);
696}
697
698static int parse_btf_bitfield(struct fetch_insn **pcode,
699 struct traceprobe_parse_context *ctx)
700{
701 struct fetch_insn *code = *pcode;
702
703 if ((ctx->last_bitsize % 8 == 0) && ctx->last_bitoffs == 0)
704 return 0;
705
706 code++;
707 if (code->op != FETCH_OP_NOP) {
708 trace_probe_log_err(ctx->offset, TOO_MANY_OPS);
709 return -EINVAL;
710 }
711 *pcode = code;
712
713 code->op = FETCH_OP_MOD_BF;
714 code->lshift = 64 - (ctx->last_bitsize + ctx->last_bitoffs);
715 code->rshift = 64 - ctx->last_bitsize;
716 code->basesize = 64 / 8;
717 return 0;
718}
719
720#else
721static void clear_btf_context(struct traceprobe_parse_context *ctx)
722{
723 ctx->btf = NULL;
724}
725
726static int query_btf_context(struct traceprobe_parse_context *ctx)
727{
728 return -EOPNOTSUPP;
729}
730
731static int parse_btf_arg(char *varname,
732 struct fetch_insn **pcode, struct fetch_insn *end,
733 struct traceprobe_parse_context *ctx)
734{
735 trace_probe_log_err(ctx->offset, NOSUP_BTFARG);
736 return -EOPNOTSUPP;
737}
738
739static int parse_btf_bitfield(struct fetch_insn **pcode,
740 struct traceprobe_parse_context *ctx)
741{
742 trace_probe_log_err(ctx->offset, NOSUP_BTFARG);
743 return -EOPNOTSUPP;
744}
745
746#define find_fetch_type_from_btf_type(ctx) \
747 find_fetch_type(NULL, ctx->flags)
748
749static int check_prepare_btf_string_fetch(char *typename,
750 struct fetch_insn **pcode,
751 struct traceprobe_parse_context *ctx)
752{
753 return 0;
754}
755
756#endif
757
758#define PARAM_MAX_STACK (THREAD_SIZE / sizeof(unsigned long))
759
760/* Parse $vars. @orig_arg points '$', which syncs to @ctx->offset */
761static int parse_probe_vars(char *orig_arg, const struct fetch_type *t,
762 struct fetch_insn **pcode,
763 struct fetch_insn *end,
764 struct traceprobe_parse_context *ctx)
765{
766 struct fetch_insn *code = *pcode;
767 int err = TP_ERR_BAD_VAR;
768 char *arg = orig_arg + 1;
769 unsigned long param;
770 int ret = 0;
771 int len;
772
773 if (ctx->flags & TPARG_FL_TEVENT) {
774 if (code->data)
775 return -EFAULT;
776 ret = parse_trace_event_arg(arg, code, ctx);
777 if (!ret)
778 return 0;
779 if (strcmp(arg, "comm") == 0 || strcmp(arg, "COMM") == 0) {
780 code->op = FETCH_OP_COMM;
781 return 0;
782 }
783 /* backward compatibility */
784 ctx->offset = 0;
785 goto inval;
786 }
787
788 if (str_has_prefix(arg, "retval")) {
789 if (!(ctx->flags & TPARG_FL_RETURN)) {
790 err = TP_ERR_RETVAL_ON_PROBE;
791 goto inval;
792 }
793 if (!(ctx->flags & TPARG_FL_KERNEL) ||
794 !IS_ENABLED(CONFIG_PROBE_EVENTS_BTF_ARGS)) {
795 code->op = FETCH_OP_RETVAL;
796 return 0;
797 }
798 return parse_btf_arg(orig_arg, pcode, end, ctx);
799 }
800
801 len = str_has_prefix(arg, "stack");
802 if (len) {
803
804 if (arg[len] == '\0') {
805 code->op = FETCH_OP_STACKP;
806 return 0;
807 }
808
809 if (isdigit(arg[len])) {
810 ret = kstrtoul(arg + len, 10, ¶m);
811 if (ret)
812 goto inval;
813
814 if ((ctx->flags & TPARG_FL_KERNEL) &&
815 param > PARAM_MAX_STACK) {
816 err = TP_ERR_BAD_STACK_NUM;
817 goto inval;
818 }
819 code->op = FETCH_OP_STACK;
820 code->param = (unsigned int)param;
821 return 0;
822 }
823 goto inval;
824 }
825
826 if (strcmp(arg, "comm") == 0 || strcmp(arg, "COMM") == 0) {
827 code->op = FETCH_OP_COMM;
828 return 0;
829 }
830
831#ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API
832 len = str_has_prefix(arg, "arg");
833 if (len && tparg_is_function_entry(ctx->flags)) {
834 ret = kstrtoul(arg + len, 10, ¶m);
835 if (ret)
836 goto inval;
837
838 if (!param || param > PARAM_MAX_STACK) {
839 err = TP_ERR_BAD_ARG_NUM;
840 goto inval;
841 }
842
843 code->op = FETCH_OP_ARG;
844 code->param = (unsigned int)param - 1;
845 /*
846 * The tracepoint probe will probe a stub function, and the
847 * first parameter of the stub is a dummy and should be ignored.
848 */
849 if (ctx->flags & TPARG_FL_TPOINT)
850 code->param++;
851 return 0;
852 }
853#endif
854
855inval:
856 __trace_probe_log_err(ctx->offset, err);
857 return -EINVAL;
858}
859
860static int str_to_immediate(char *str, unsigned long *imm)
861{
862 if (isdigit(str[0]))
863 return kstrtoul(str, 0, imm);
864 else if (str[0] == '-')
865 return kstrtol(str, 0, (long *)imm);
866 else if (str[0] == '+')
867 return kstrtol(str + 1, 0, (long *)imm);
868 return -EINVAL;
869}
870
871static int __parse_imm_string(char *str, char **pbuf, int offs)
872{
873 size_t len = strlen(str);
874
875 if (str[len - 1] != '"') {
876 trace_probe_log_err(offs + len, IMMSTR_NO_CLOSE);
877 return -EINVAL;
878 }
879 *pbuf = kstrndup(str, len - 1, GFP_KERNEL);
880 if (!*pbuf)
881 return -ENOMEM;
882 return 0;
883}
884
885/* Recursive argument parser */
886static int
887parse_probe_arg(char *arg, const struct fetch_type *type,
888 struct fetch_insn **pcode, struct fetch_insn *end,
889 struct traceprobe_parse_context *ctx)
890{
891 struct fetch_insn *code = *pcode;
892 unsigned long param;
893 int deref = FETCH_OP_DEREF;
894 long offset = 0;
895 char *tmp;
896 int ret = 0;
897
898 switch (arg[0]) {
899 case '$':
900 ret = parse_probe_vars(arg, type, pcode, end, ctx);
901 break;
902
903 case '%': /* named register */
904 if (ctx->flags & (TPARG_FL_TEVENT | TPARG_FL_FPROBE)) {
905 /* eprobe and fprobe do not handle registers */
906 trace_probe_log_err(ctx->offset, BAD_VAR);
907 break;
908 }
909 ret = regs_query_register_offset(arg + 1);
910 if (ret >= 0) {
911 code->op = FETCH_OP_REG;
912 code->param = (unsigned int)ret;
913 ret = 0;
914 } else
915 trace_probe_log_err(ctx->offset, BAD_REG_NAME);
916 break;
917
918 case '@': /* memory, file-offset or symbol */
919 if (isdigit(arg[1])) {
920 ret = kstrtoul(arg + 1, 0, ¶m);
921 if (ret) {
922 trace_probe_log_err(ctx->offset, BAD_MEM_ADDR);
923 break;
924 }
925 /* load address */
926 code->op = FETCH_OP_IMM;
927 code->immediate = param;
928 } else if (arg[1] == '+') {
929 /* kprobes don't support file offsets */
930 if (ctx->flags & TPARG_FL_KERNEL) {
931 trace_probe_log_err(ctx->offset, FILE_ON_KPROBE);
932 return -EINVAL;
933 }
934 ret = kstrtol(arg + 2, 0, &offset);
935 if (ret) {
936 trace_probe_log_err(ctx->offset, BAD_FILE_OFFS);
937 break;
938 }
939
940 code->op = FETCH_OP_FOFFS;
941 code->immediate = (unsigned long)offset; // imm64?
942 } else {
943 /* uprobes don't support symbols */
944 if (!(ctx->flags & TPARG_FL_KERNEL)) {
945 trace_probe_log_err(ctx->offset, SYM_ON_UPROBE);
946 return -EINVAL;
947 }
948 /* Preserve symbol for updating */
949 code->op = FETCH_NOP_SYMBOL;
950 code->data = kstrdup(arg + 1, GFP_KERNEL);
951 if (!code->data)
952 return -ENOMEM;
953 if (++code == end) {
954 trace_probe_log_err(ctx->offset, TOO_MANY_OPS);
955 return -EINVAL;
956 }
957 code->op = FETCH_OP_IMM;
958 code->immediate = 0;
959 }
960 /* These are fetching from memory */
961 if (++code == end) {
962 trace_probe_log_err(ctx->offset, TOO_MANY_OPS);
963 return -EINVAL;
964 }
965 *pcode = code;
966 code->op = FETCH_OP_DEREF;
967 code->offset = offset;
968 break;
969
970 case '+': /* deref memory */
971 case '-':
972 if (arg[1] == 'u') {
973 deref = FETCH_OP_UDEREF;
974 arg[1] = arg[0];
975 arg++;
976 }
977 if (arg[0] == '+')
978 arg++; /* Skip '+', because kstrtol() rejects it. */
979 tmp = strchr(arg, '(');
980 if (!tmp) {
981 trace_probe_log_err(ctx->offset, DEREF_NEED_BRACE);
982 return -EINVAL;
983 }
984 *tmp = '\0';
985 ret = kstrtol(arg, 0, &offset);
986 if (ret) {
987 trace_probe_log_err(ctx->offset, BAD_DEREF_OFFS);
988 break;
989 }
990 ctx->offset += (tmp + 1 - arg) + (arg[0] != '-' ? 1 : 0);
991 arg = tmp + 1;
992 tmp = strrchr(arg, ')');
993 if (!tmp) {
994 trace_probe_log_err(ctx->offset + strlen(arg),
995 DEREF_OPEN_BRACE);
996 return -EINVAL;
997 } else {
998 const struct fetch_type *t2 = find_fetch_type(NULL, ctx->flags);
999 int cur_offs = ctx->offset;
1000
1001 *tmp = '\0';
1002 ret = parse_probe_arg(arg, t2, &code, end, ctx);
1003 if (ret)
1004 break;
1005 ctx->offset = cur_offs;
1006 if (code->op == FETCH_OP_COMM ||
1007 code->op == FETCH_OP_DATA) {
1008 trace_probe_log_err(ctx->offset, COMM_CANT_DEREF);
1009 return -EINVAL;
1010 }
1011 if (++code == end) {
1012 trace_probe_log_err(ctx->offset, TOO_MANY_OPS);
1013 return -EINVAL;
1014 }
1015 *pcode = code;
1016
1017 code->op = deref;
1018 code->offset = offset;
1019 /* Reset the last type if used */
1020 ctx->last_type = NULL;
1021 }
1022 break;
1023 case '\\': /* Immediate value */
1024 if (arg[1] == '"') { /* Immediate string */
1025 ret = __parse_imm_string(arg + 2, &tmp, ctx->offset + 2);
1026 if (ret)
1027 break;
1028 code->op = FETCH_OP_DATA;
1029 code->data = tmp;
1030 } else {
1031 ret = str_to_immediate(arg + 1, &code->immediate);
1032 if (ret)
1033 trace_probe_log_err(ctx->offset + 1, BAD_IMM);
1034 else
1035 code->op = FETCH_OP_IMM;
1036 }
1037 break;
1038 default:
1039 if (isalpha(arg[0]) || arg[0] == '_') { /* BTF variable */
1040 if (!tparg_is_function_entry(ctx->flags)) {
1041 trace_probe_log_err(ctx->offset, NOSUP_BTFARG);
1042 return -EINVAL;
1043 }
1044 ret = parse_btf_arg(arg, pcode, end, ctx);
1045 break;
1046 }
1047 }
1048 if (!ret && code->op == FETCH_OP_NOP) {
1049 /* Parsed, but do not find fetch method */
1050 trace_probe_log_err(ctx->offset, BAD_FETCH_ARG);
1051 ret = -EINVAL;
1052 }
1053 return ret;
1054}
1055
1056#define BYTES_TO_BITS(nb) ((BITS_PER_LONG * (nb)) / sizeof(long))
1057
1058/* Bitfield type needs to be parsed into a fetch function */
1059static int __parse_bitfield_probe_arg(const char *bf,
1060 const struct fetch_type *t,
1061 struct fetch_insn **pcode)
1062{
1063 struct fetch_insn *code = *pcode;
1064 unsigned long bw, bo;
1065 char *tail;
1066
1067 if (*bf != 'b')
1068 return 0;
1069
1070 bw = simple_strtoul(bf + 1, &tail, 0); /* Use simple one */
1071
1072 if (bw == 0 || *tail != '@')
1073 return -EINVAL;
1074
1075 bf = tail + 1;
1076 bo = simple_strtoul(bf, &tail, 0);
1077
1078 if (tail == bf || *tail != '/')
1079 return -EINVAL;
1080 code++;
1081 if (code->op != FETCH_OP_NOP)
1082 return -EINVAL;
1083 *pcode = code;
1084
1085 code->op = FETCH_OP_MOD_BF;
1086 code->lshift = BYTES_TO_BITS(t->size) - (bw + bo);
1087 code->rshift = BYTES_TO_BITS(t->size) - bw;
1088 code->basesize = t->size;
1089
1090 return (BYTES_TO_BITS(t->size) < (bw + bo)) ? -EINVAL : 0;
1091}
1092
1093/* String length checking wrapper */
1094static int traceprobe_parse_probe_arg_body(const char *argv, ssize_t *size,
1095 struct probe_arg *parg,
1096 struct traceprobe_parse_context *ctx)
1097{
1098 struct fetch_insn *code, *scode, *tmp = NULL;
1099 char *t, *t2, *t3;
1100 int ret, len;
1101 char *arg;
1102
1103 arg = kstrdup(argv, GFP_KERNEL);
1104 if (!arg)
1105 return -ENOMEM;
1106
1107 ret = -EINVAL;
1108 len = strlen(arg);
1109 if (len > MAX_ARGSTR_LEN) {
1110 trace_probe_log_err(ctx->offset, ARG_TOO_LONG);
1111 goto out;
1112 } else if (len == 0) {
1113 trace_probe_log_err(ctx->offset, NO_ARG_BODY);
1114 goto out;
1115 }
1116
1117 ret = -ENOMEM;
1118 parg->comm = kstrdup(arg, GFP_KERNEL);
1119 if (!parg->comm)
1120 goto out;
1121
1122 ret = -EINVAL;
1123 t = strchr(arg, ':');
1124 if (t) {
1125 *t = '\0';
1126 t2 = strchr(++t, '[');
1127 if (t2) {
1128 *t2++ = '\0';
1129 t3 = strchr(t2, ']');
1130 if (!t3) {
1131 int offs = t2 + strlen(t2) - arg;
1132
1133 trace_probe_log_err(ctx->offset + offs,
1134 ARRAY_NO_CLOSE);
1135 goto out;
1136 } else if (t3[1] != '\0') {
1137 trace_probe_log_err(ctx->offset + t3 + 1 - arg,
1138 BAD_ARRAY_SUFFIX);
1139 goto out;
1140 }
1141 *t3 = '\0';
1142 if (kstrtouint(t2, 0, &parg->count) || !parg->count) {
1143 trace_probe_log_err(ctx->offset + t2 - arg,
1144 BAD_ARRAY_NUM);
1145 goto out;
1146 }
1147 if (parg->count > MAX_ARRAY_LEN) {
1148 trace_probe_log_err(ctx->offset + t2 - arg,
1149 ARRAY_TOO_BIG);
1150 goto out;
1151 }
1152 }
1153 }
1154
1155 /*
1156 * Since $comm and immediate string can not be dereferenced,
1157 * we can find those by strcmp. But ignore for eprobes.
1158 */
1159 if (!(ctx->flags & TPARG_FL_TEVENT) &&
1160 (strcmp(arg, "$comm") == 0 || strcmp(arg, "$COMM") == 0 ||
1161 strncmp(arg, "\\\"", 2) == 0)) {
1162 /* The type of $comm must be "string", and not an array type. */
1163 if (parg->count || (t && strcmp(t, "string"))) {
1164 trace_probe_log_err(ctx->offset + (t ? (t - arg) : 0),
1165 NEED_STRING_TYPE);
1166 goto out;
1167 }
1168 parg->type = find_fetch_type("string", ctx->flags);
1169 } else
1170 parg->type = find_fetch_type(t, ctx->flags);
1171 if (!parg->type) {
1172 trace_probe_log_err(ctx->offset + (t ? (t - arg) : 0), BAD_TYPE);
1173 goto out;
1174 }
1175
1176 code = tmp = kcalloc(FETCH_INSN_MAX, sizeof(*code), GFP_KERNEL);
1177 if (!code)
1178 goto out;
1179 code[FETCH_INSN_MAX - 1].op = FETCH_OP_END;
1180
1181 ctx->last_type = NULL;
1182 ret = parse_probe_arg(arg, parg->type, &code, &code[FETCH_INSN_MAX - 1],
1183 ctx);
1184 if (ret)
1185 goto fail;
1186
1187 /* Update storing type if BTF is available */
1188 if (IS_ENABLED(CONFIG_PROBE_EVENTS_BTF_ARGS) &&
1189 ctx->last_type) {
1190 if (!t) {
1191 parg->type = find_fetch_type_from_btf_type(ctx);
1192 } else if (strstr(t, "string")) {
1193 ret = check_prepare_btf_string_fetch(t, &code, ctx);
1194 if (ret)
1195 goto fail;
1196 }
1197 }
1198 parg->offset = *size;
1199 *size += parg->type->size * (parg->count ?: 1);
1200
1201 if (parg->count) {
1202 len = strlen(parg->type->fmttype) + 6;
1203 parg->fmt = kmalloc(len, GFP_KERNEL);
1204 if (!parg->fmt) {
1205 ret = -ENOMEM;
1206 goto out;
1207 }
1208 snprintf(parg->fmt, len, "%s[%d]", parg->type->fmttype,
1209 parg->count);
1210 }
1211
1212 ret = -EINVAL;
1213 /* Store operation */
1214 if (parg->type->is_string) {
1215 if (!strcmp(parg->type->name, "symstr")) {
1216 if (code->op != FETCH_OP_REG && code->op != FETCH_OP_STACK &&
1217 code->op != FETCH_OP_RETVAL && code->op != FETCH_OP_ARG &&
1218 code->op != FETCH_OP_DEREF && code->op != FETCH_OP_TP_ARG) {
1219 trace_probe_log_err(ctx->offset + (t ? (t - arg) : 0),
1220 BAD_SYMSTRING);
1221 goto fail;
1222 }
1223 } else {
1224 if (code->op != FETCH_OP_DEREF && code->op != FETCH_OP_UDEREF &&
1225 code->op != FETCH_OP_IMM && code->op != FETCH_OP_COMM &&
1226 code->op != FETCH_OP_DATA && code->op != FETCH_OP_TP_ARG) {
1227 trace_probe_log_err(ctx->offset + (t ? (t - arg) : 0),
1228 BAD_STRING);
1229 goto fail;
1230 }
1231 }
1232 if (!strcmp(parg->type->name, "symstr") ||
1233 (code->op == FETCH_OP_IMM || code->op == FETCH_OP_COMM ||
1234 code->op == FETCH_OP_DATA) || code->op == FETCH_OP_TP_ARG ||
1235 parg->count) {
1236 /*
1237 * IMM, DATA and COMM is pointing actual address, those
1238 * must be kept, and if parg->count != 0, this is an
1239 * array of string pointers instead of string address
1240 * itself.
1241 * For the symstr, it doesn't need to dereference, thus
1242 * it just get the value.
1243 */
1244 code++;
1245 if (code->op != FETCH_OP_NOP) {
1246 trace_probe_log_err(ctx->offset, TOO_MANY_OPS);
1247 goto fail;
1248 }
1249 }
1250 /* If op == DEREF, replace it with STRING */
1251 if (!strcmp(parg->type->name, "ustring") ||
1252 code->op == FETCH_OP_UDEREF)
1253 code->op = FETCH_OP_ST_USTRING;
1254 else if (!strcmp(parg->type->name, "symstr"))
1255 code->op = FETCH_OP_ST_SYMSTR;
1256 else
1257 code->op = FETCH_OP_ST_STRING;
1258 code->size = parg->type->size;
1259 parg->dynamic = true;
1260 } else if (code->op == FETCH_OP_DEREF) {
1261 code->op = FETCH_OP_ST_MEM;
1262 code->size = parg->type->size;
1263 } else if (code->op == FETCH_OP_UDEREF) {
1264 code->op = FETCH_OP_ST_UMEM;
1265 code->size = parg->type->size;
1266 } else {
1267 code++;
1268 if (code->op != FETCH_OP_NOP) {
1269 trace_probe_log_err(ctx->offset, TOO_MANY_OPS);
1270 goto fail;
1271 }
1272 code->op = FETCH_OP_ST_RAW;
1273 code->size = parg->type->size;
1274 }
1275 scode = code;
1276 /* Modify operation */
1277 if (t != NULL) {
1278 ret = __parse_bitfield_probe_arg(t, parg->type, &code);
1279 if (ret) {
1280 trace_probe_log_err(ctx->offset + t - arg, BAD_BITFIELD);
1281 goto fail;
1282 }
1283 } else if (IS_ENABLED(CONFIG_PROBE_EVENTS_BTF_ARGS) &&
1284 ctx->last_type) {
1285 ret = parse_btf_bitfield(&code, ctx);
1286 if (ret)
1287 goto fail;
1288 }
1289 ret = -EINVAL;
1290 /* Loop(Array) operation */
1291 if (parg->count) {
1292 if (scode->op != FETCH_OP_ST_MEM &&
1293 scode->op != FETCH_OP_ST_STRING &&
1294 scode->op != FETCH_OP_ST_USTRING) {
1295 trace_probe_log_err(ctx->offset + (t ? (t - arg) : 0),
1296 BAD_STRING);
1297 goto fail;
1298 }
1299 code++;
1300 if (code->op != FETCH_OP_NOP) {
1301 trace_probe_log_err(ctx->offset, TOO_MANY_OPS);
1302 goto fail;
1303 }
1304 code->op = FETCH_OP_LP_ARRAY;
1305 code->param = parg->count;
1306 }
1307 code++;
1308 code->op = FETCH_OP_END;
1309
1310 ret = 0;
1311 /* Shrink down the code buffer */
1312 parg->code = kcalloc(code - tmp + 1, sizeof(*code), GFP_KERNEL);
1313 if (!parg->code)
1314 ret = -ENOMEM;
1315 else
1316 memcpy(parg->code, tmp, sizeof(*code) * (code - tmp + 1));
1317
1318fail:
1319 if (ret) {
1320 for (code = tmp; code < tmp + FETCH_INSN_MAX; code++)
1321 if (code->op == FETCH_NOP_SYMBOL ||
1322 code->op == FETCH_OP_DATA)
1323 kfree(code->data);
1324 }
1325 kfree(tmp);
1326out:
1327 kfree(arg);
1328
1329 return ret;
1330}
1331
1332/* Return 1 if name is reserved or already used by another argument */
1333static int traceprobe_conflict_field_name(const char *name,
1334 struct probe_arg *args, int narg)
1335{
1336 int i;
1337
1338 for (i = 0; i < ARRAY_SIZE(reserved_field_names); i++)
1339 if (strcmp(reserved_field_names[i], name) == 0)
1340 return 1;
1341
1342 for (i = 0; i < narg; i++)
1343 if (strcmp(args[i].name, name) == 0)
1344 return 1;
1345
1346 return 0;
1347}
1348
1349static char *generate_probe_arg_name(const char *arg, int idx)
1350{
1351 char *name = NULL;
1352 const char *end;
1353
1354 /*
1355 * If argument name is omitted, try arg as a name (BTF variable)
1356 * or "argN".
1357 */
1358 if (IS_ENABLED(CONFIG_PROBE_EVENTS_BTF_ARGS)) {
1359 end = strchr(arg, ':');
1360 if (!end)
1361 end = arg + strlen(arg);
1362
1363 name = kmemdup_nul(arg, end - arg, GFP_KERNEL);
1364 if (!name || !is_good_name(name)) {
1365 kfree(name);
1366 name = NULL;
1367 }
1368 }
1369
1370 if (!name)
1371 name = kasprintf(GFP_KERNEL, "arg%d", idx + 1);
1372
1373 return name;
1374}
1375
1376int traceprobe_parse_probe_arg(struct trace_probe *tp, int i, const char *arg,
1377 struct traceprobe_parse_context *ctx)
1378{
1379 struct probe_arg *parg = &tp->args[i];
1380 const char *body;
1381
1382 /* Increment count for freeing args in error case */
1383 tp->nr_args++;
1384
1385 body = strchr(arg, '=');
1386 if (body) {
1387 if (body - arg > MAX_ARG_NAME_LEN) {
1388 trace_probe_log_err(0, ARG_NAME_TOO_LONG);
1389 return -EINVAL;
1390 } else if (body == arg) {
1391 trace_probe_log_err(0, NO_ARG_NAME);
1392 return -EINVAL;
1393 }
1394 parg->name = kmemdup_nul(arg, body - arg, GFP_KERNEL);
1395 body++;
1396 } else {
1397 parg->name = generate_probe_arg_name(arg, i);
1398 body = arg;
1399 }
1400 if (!parg->name)
1401 return -ENOMEM;
1402
1403 if (!is_good_name(parg->name)) {
1404 trace_probe_log_err(0, BAD_ARG_NAME);
1405 return -EINVAL;
1406 }
1407 if (traceprobe_conflict_field_name(parg->name, tp->args, i)) {
1408 trace_probe_log_err(0, USED_ARG_NAME);
1409 return -EINVAL;
1410 }
1411 ctx->offset = body - arg;
1412 /* Parse fetch argument */
1413 return traceprobe_parse_probe_arg_body(body, &tp->size, parg, ctx);
1414}
1415
1416void traceprobe_free_probe_arg(struct probe_arg *arg)
1417{
1418 struct fetch_insn *code = arg->code;
1419
1420 while (code && code->op != FETCH_OP_END) {
1421 if (code->op == FETCH_NOP_SYMBOL ||
1422 code->op == FETCH_OP_DATA)
1423 kfree(code->data);
1424 code++;
1425 }
1426 kfree(arg->code);
1427 kfree(arg->name);
1428 kfree(arg->comm);
1429 kfree(arg->fmt);
1430}
1431
1432static int argv_has_var_arg(int argc, const char *argv[], int *args_idx,
1433 struct traceprobe_parse_context *ctx)
1434{
1435 int i, found = 0;
1436
1437 for (i = 0; i < argc; i++)
1438 if (str_has_prefix(argv[i], "$arg")) {
1439 trace_probe_log_set_index(i + 2);
1440
1441 if (!tparg_is_function_entry(ctx->flags)) {
1442 trace_probe_log_err(0, NOFENTRY_ARGS);
1443 return -EINVAL;
1444 }
1445
1446 if (isdigit(argv[i][4])) {
1447 found = 1;
1448 continue;
1449 }
1450
1451 if (argv[i][4] != '*') {
1452 trace_probe_log_err(0, BAD_VAR);
1453 return -EINVAL;
1454 }
1455
1456 if (*args_idx >= 0 && *args_idx < argc) {
1457 trace_probe_log_err(0, DOUBLE_ARGS);
1458 return -EINVAL;
1459 }
1460 found = 1;
1461 *args_idx = i;
1462 }
1463
1464 return found;
1465}
1466
1467static int sprint_nth_btf_arg(int idx, const char *type,
1468 char *buf, int bufsize,
1469 struct traceprobe_parse_context *ctx)
1470{
1471 const char *name;
1472 int ret;
1473
1474 if (idx >= ctx->nr_params) {
1475 trace_probe_log_err(0, NO_BTFARG);
1476 return -ENOENT;
1477 }
1478 name = btf_name_by_offset(ctx->btf, ctx->params[idx].name_off);
1479 if (!name) {
1480 trace_probe_log_err(0, NO_BTF_ENTRY);
1481 return -ENOENT;
1482 }
1483 ret = snprintf(buf, bufsize, "%s%s", name, type);
1484 if (ret >= bufsize) {
1485 trace_probe_log_err(0, ARGS_2LONG);
1486 return -E2BIG;
1487 }
1488 return ret;
1489}
1490
1491/* Return new_argv which must be freed after use */
1492const char **traceprobe_expand_meta_args(int argc, const char *argv[],
1493 int *new_argc, char *buf, int bufsize,
1494 struct traceprobe_parse_context *ctx)
1495{
1496 const struct btf_param *params = NULL;
1497 int i, j, n, used, ret, args_idx = -1;
1498 const char **new_argv = NULL;
1499
1500 ret = argv_has_var_arg(argc, argv, &args_idx, ctx);
1501 if (ret < 0)
1502 return ERR_PTR(ret);
1503
1504 if (!ret) {
1505 *new_argc = argc;
1506 return NULL;
1507 }
1508
1509 ret = query_btf_context(ctx);
1510 if (ret < 0 || ctx->nr_params == 0) {
1511 if (args_idx != -1) {
1512 /* $arg* requires BTF info */
1513 trace_probe_log_err(0, NOSUP_BTFARG);
1514 return (const char **)params;
1515 }
1516 *new_argc = argc;
1517 return NULL;
1518 }
1519
1520 if (args_idx >= 0)
1521 *new_argc = argc + ctx->nr_params - 1;
1522 else
1523 *new_argc = argc;
1524
1525 new_argv = kcalloc(*new_argc, sizeof(char *), GFP_KERNEL);
1526 if (!new_argv)
1527 return ERR_PTR(-ENOMEM);
1528
1529 used = 0;
1530 for (i = 0, j = 0; i < argc; i++) {
1531 trace_probe_log_set_index(i + 2);
1532 if (i == args_idx) {
1533 for (n = 0; n < ctx->nr_params; n++) {
1534 ret = sprint_nth_btf_arg(n, "", buf + used,
1535 bufsize - used, ctx);
1536 if (ret < 0)
1537 goto error;
1538
1539 new_argv[j++] = buf + used;
1540 used += ret + 1;
1541 }
1542 continue;
1543 }
1544
1545 if (str_has_prefix(argv[i], "$arg")) {
1546 char *type = NULL;
1547
1548 n = simple_strtoul(argv[i] + 4, &type, 10);
1549 if (type && !(*type == ':' || *type == '\0')) {
1550 trace_probe_log_err(0, BAD_VAR);
1551 ret = -ENOENT;
1552 goto error;
1553 }
1554 /* Note: $argN starts from $arg1 */
1555 ret = sprint_nth_btf_arg(n - 1, type, buf + used,
1556 bufsize - used, ctx);
1557 if (ret < 0)
1558 goto error;
1559 new_argv[j++] = buf + used;
1560 used += ret + 1;
1561 } else
1562 new_argv[j++] = argv[i];
1563 }
1564
1565 return new_argv;
1566
1567error:
1568 kfree(new_argv);
1569 return ERR_PTR(ret);
1570}
1571
1572void traceprobe_finish_parse(struct traceprobe_parse_context *ctx)
1573{
1574 clear_btf_context(ctx);
1575}
1576
1577int traceprobe_update_arg(struct probe_arg *arg)
1578{
1579 struct fetch_insn *code = arg->code;
1580 long offset;
1581 char *tmp;
1582 char c;
1583 int ret = 0;
1584
1585 while (code && code->op != FETCH_OP_END) {
1586 if (code->op == FETCH_NOP_SYMBOL) {
1587 if (code[1].op != FETCH_OP_IMM)
1588 return -EINVAL;
1589
1590 tmp = strpbrk(code->data, "+-");
1591 if (tmp)
1592 c = *tmp;
1593 ret = traceprobe_split_symbol_offset(code->data,
1594 &offset);
1595 if (ret)
1596 return ret;
1597
1598 code[1].immediate =
1599 (unsigned long)kallsyms_lookup_name(code->data);
1600 if (tmp)
1601 *tmp = c;
1602 if (!code[1].immediate)
1603 return -ENOENT;
1604 code[1].immediate += offset;
1605 }
1606 code++;
1607 }
1608 return 0;
1609}
1610
1611/* When len=0, we just calculate the needed length */
1612#define LEN_OR_ZERO (len ? len - pos : 0)
1613static int __set_print_fmt(struct trace_probe *tp, char *buf, int len,
1614 enum probe_print_type ptype)
1615{
1616 struct probe_arg *parg;
1617 int i, j;
1618 int pos = 0;
1619 const char *fmt, *arg;
1620
1621 switch (ptype) {
1622 case PROBE_PRINT_NORMAL:
1623 fmt = "(%lx)";
1624 arg = ", REC->" FIELD_STRING_IP;
1625 break;
1626 case PROBE_PRINT_RETURN:
1627 fmt = "(%lx <- %lx)";
1628 arg = ", REC->" FIELD_STRING_FUNC ", REC->" FIELD_STRING_RETIP;
1629 break;
1630 case PROBE_PRINT_EVENT:
1631 fmt = "";
1632 arg = "";
1633 break;
1634 default:
1635 WARN_ON_ONCE(1);
1636 return 0;
1637 }
1638
1639 pos += snprintf(buf + pos, LEN_OR_ZERO, "\"%s", fmt);
1640
1641 for (i = 0; i < tp->nr_args; i++) {
1642 parg = tp->args + i;
1643 pos += snprintf(buf + pos, LEN_OR_ZERO, " %s=", parg->name);
1644 if (parg->count) {
1645 pos += snprintf(buf + pos, LEN_OR_ZERO, "{%s",
1646 parg->type->fmt);
1647 for (j = 1; j < parg->count; j++)
1648 pos += snprintf(buf + pos, LEN_OR_ZERO, ",%s",
1649 parg->type->fmt);
1650 pos += snprintf(buf + pos, LEN_OR_ZERO, "}");
1651 } else
1652 pos += snprintf(buf + pos, LEN_OR_ZERO, "%s",
1653 parg->type->fmt);
1654 }
1655
1656 pos += snprintf(buf + pos, LEN_OR_ZERO, "\"%s", arg);
1657
1658 for (i = 0; i < tp->nr_args; i++) {
1659 parg = tp->args + i;
1660 if (parg->count) {
1661 if (parg->type->is_string)
1662 fmt = ", __get_str(%s[%d])";
1663 else
1664 fmt = ", REC->%s[%d]";
1665 for (j = 0; j < parg->count; j++)
1666 pos += snprintf(buf + pos, LEN_OR_ZERO,
1667 fmt, parg->name, j);
1668 } else {
1669 if (parg->type->is_string)
1670 fmt = ", __get_str(%s)";
1671 else
1672 fmt = ", REC->%s";
1673 pos += snprintf(buf + pos, LEN_OR_ZERO,
1674 fmt, parg->name);
1675 }
1676 }
1677
1678 /* return the length of print_fmt */
1679 return pos;
1680}
1681#undef LEN_OR_ZERO
1682
1683int traceprobe_set_print_fmt(struct trace_probe *tp, enum probe_print_type ptype)
1684{
1685 struct trace_event_call *call = trace_probe_event_call(tp);
1686 int len;
1687 char *print_fmt;
1688
1689 /* First: called with 0 length to calculate the needed length */
1690 len = __set_print_fmt(tp, NULL, 0, ptype);
1691 print_fmt = kmalloc(len + 1, GFP_KERNEL);
1692 if (!print_fmt)
1693 return -ENOMEM;
1694
1695 /* Second: actually write the @print_fmt */
1696 __set_print_fmt(tp, print_fmt, len + 1, ptype);
1697 call->print_fmt = print_fmt;
1698
1699 return 0;
1700}
1701
1702int traceprobe_define_arg_fields(struct trace_event_call *event_call,
1703 size_t offset, struct trace_probe *tp)
1704{
1705 int ret, i;
1706
1707 /* Set argument names as fields */
1708 for (i = 0; i < tp->nr_args; i++) {
1709 struct probe_arg *parg = &tp->args[i];
1710 const char *fmt = parg->type->fmttype;
1711 int size = parg->type->size;
1712
1713 if (parg->fmt)
1714 fmt = parg->fmt;
1715 if (parg->count)
1716 size *= parg->count;
1717 ret = trace_define_field(event_call, fmt, parg->name,
1718 offset + parg->offset, size,
1719 parg->type->is_signed,
1720 FILTER_OTHER);
1721 if (ret)
1722 return ret;
1723 }
1724 return 0;
1725}
1726
1727static void trace_probe_event_free(struct trace_probe_event *tpe)
1728{
1729 kfree(tpe->class.system);
1730 kfree(tpe->call.name);
1731 kfree(tpe->call.print_fmt);
1732 kfree(tpe);
1733}
1734
1735int trace_probe_append(struct trace_probe *tp, struct trace_probe *to)
1736{
1737 if (trace_probe_has_sibling(tp))
1738 return -EBUSY;
1739
1740 list_del_init(&tp->list);
1741 trace_probe_event_free(tp->event);
1742
1743 tp->event = to->event;
1744 list_add_tail(&tp->list, trace_probe_probe_list(to));
1745
1746 return 0;
1747}
1748
1749void trace_probe_unlink(struct trace_probe *tp)
1750{
1751 list_del_init(&tp->list);
1752 if (list_empty(trace_probe_probe_list(tp)))
1753 trace_probe_event_free(tp->event);
1754 tp->event = NULL;
1755}
1756
1757void trace_probe_cleanup(struct trace_probe *tp)
1758{
1759 int i;
1760
1761 for (i = 0; i < tp->nr_args; i++)
1762 traceprobe_free_probe_arg(&tp->args[i]);
1763
1764 if (tp->event)
1765 trace_probe_unlink(tp);
1766}
1767
1768int trace_probe_init(struct trace_probe *tp, const char *event,
1769 const char *group, bool alloc_filter)
1770{
1771 struct trace_event_call *call;
1772 size_t size = sizeof(struct trace_probe_event);
1773 int ret = 0;
1774
1775 if (!event || !group)
1776 return -EINVAL;
1777
1778 if (alloc_filter)
1779 size += sizeof(struct trace_uprobe_filter);
1780
1781 tp->event = kzalloc(size, GFP_KERNEL);
1782 if (!tp->event)
1783 return -ENOMEM;
1784
1785 INIT_LIST_HEAD(&tp->event->files);
1786 INIT_LIST_HEAD(&tp->event->class.fields);
1787 INIT_LIST_HEAD(&tp->event->probes);
1788 INIT_LIST_HEAD(&tp->list);
1789 list_add(&tp->list, &tp->event->probes);
1790
1791 call = trace_probe_event_call(tp);
1792 call->class = &tp->event->class;
1793 call->name = kstrdup(event, GFP_KERNEL);
1794 if (!call->name) {
1795 ret = -ENOMEM;
1796 goto error;
1797 }
1798
1799 tp->event->class.system = kstrdup(group, GFP_KERNEL);
1800 if (!tp->event->class.system) {
1801 ret = -ENOMEM;
1802 goto error;
1803 }
1804
1805 return 0;
1806
1807error:
1808 trace_probe_cleanup(tp);
1809 return ret;
1810}
1811
1812static struct trace_event_call *
1813find_trace_event_call(const char *system, const char *event_name)
1814{
1815 struct trace_event_call *tp_event;
1816 const char *name;
1817
1818 list_for_each_entry(tp_event, &ftrace_events, list) {
1819 if (!tp_event->class->system ||
1820 strcmp(system, tp_event->class->system))
1821 continue;
1822 name = trace_event_name(tp_event);
1823 if (!name || strcmp(event_name, name))
1824 continue;
1825 return tp_event;
1826 }
1827
1828 return NULL;
1829}
1830
1831int trace_probe_register_event_call(struct trace_probe *tp)
1832{
1833 struct trace_event_call *call = trace_probe_event_call(tp);
1834 int ret;
1835
1836 lockdep_assert_held(&event_mutex);
1837
1838 if (find_trace_event_call(trace_probe_group_name(tp),
1839 trace_probe_name(tp)))
1840 return -EEXIST;
1841
1842 ret = register_trace_event(&call->event);
1843 if (!ret)
1844 return -ENODEV;
1845
1846 ret = trace_add_event_call(call);
1847 if (ret)
1848 unregister_trace_event(&call->event);
1849
1850 return ret;
1851}
1852
1853int trace_probe_add_file(struct trace_probe *tp, struct trace_event_file *file)
1854{
1855 struct event_file_link *link;
1856
1857 link = kmalloc(sizeof(*link), GFP_KERNEL);
1858 if (!link)
1859 return -ENOMEM;
1860
1861 link->file = file;
1862 INIT_LIST_HEAD(&link->list);
1863 list_add_tail_rcu(&link->list, &tp->event->files);
1864 trace_probe_set_flag(tp, TP_FLAG_TRACE);
1865 return 0;
1866}
1867
1868struct event_file_link *trace_probe_get_file_link(struct trace_probe *tp,
1869 struct trace_event_file *file)
1870{
1871 struct event_file_link *link;
1872
1873 trace_probe_for_each_link(link, tp) {
1874 if (link->file == file)
1875 return link;
1876 }
1877
1878 return NULL;
1879}
1880
1881int trace_probe_remove_file(struct trace_probe *tp,
1882 struct trace_event_file *file)
1883{
1884 struct event_file_link *link;
1885
1886 link = trace_probe_get_file_link(tp, file);
1887 if (!link)
1888 return -ENOENT;
1889
1890 list_del_rcu(&link->list);
1891 kvfree_rcu_mightsleep(link);
1892
1893 if (list_empty(&tp->event->files))
1894 trace_probe_clear_flag(tp, TP_FLAG_TRACE);
1895
1896 return 0;
1897}
1898
1899/*
1900 * Return the smallest index of different type argument (start from 1).
1901 * If all argument types and name are same, return 0.
1902 */
1903int trace_probe_compare_arg_type(struct trace_probe *a, struct trace_probe *b)
1904{
1905 int i;
1906
1907 /* In case of more arguments */
1908 if (a->nr_args < b->nr_args)
1909 return a->nr_args + 1;
1910 if (a->nr_args > b->nr_args)
1911 return b->nr_args + 1;
1912
1913 for (i = 0; i < a->nr_args; i++) {
1914 if ((b->nr_args <= i) ||
1915 ((a->args[i].type != b->args[i].type) ||
1916 (a->args[i].count != b->args[i].count) ||
1917 strcmp(a->args[i].name, b->args[i].name)))
1918 return i + 1;
1919 }
1920
1921 return 0;
1922}
1923
1924bool trace_probe_match_command_args(struct trace_probe *tp,
1925 int argc, const char **argv)
1926{
1927 char buf[MAX_ARGSTR_LEN + 1];
1928 int i;
1929
1930 if (tp->nr_args < argc)
1931 return false;
1932
1933 for (i = 0; i < argc; i++) {
1934 snprintf(buf, sizeof(buf), "%s=%s",
1935 tp->args[i].name, tp->args[i].comm);
1936 if (strcmp(buf, argv[i]))
1937 return false;
1938 }
1939 return true;
1940}
1941
1942int trace_probe_create(const char *raw_command, int (*createfn)(int, const char **))
1943{
1944 int argc = 0, ret = 0;
1945 char **argv;
1946
1947 argv = argv_split(GFP_KERNEL, raw_command, &argc);
1948 if (!argv)
1949 return -ENOMEM;
1950
1951 if (argc)
1952 ret = createfn(argc, (const char **)argv);
1953
1954 argv_free(argv);
1955
1956 return ret;
1957}
1958
1959int trace_probe_print_args(struct trace_seq *s, struct probe_arg *args, int nr_args,
1960 u8 *data, void *field)
1961{
1962 void *p;
1963 int i, j;
1964
1965 for (i = 0; i < nr_args; i++) {
1966 struct probe_arg *a = args + i;
1967
1968 trace_seq_printf(s, " %s=", a->name);
1969 if (likely(!a->count)) {
1970 if (!a->type->print(s, data + a->offset, field))
1971 return -ENOMEM;
1972 continue;
1973 }
1974 trace_seq_putc(s, '{');
1975 p = data + a->offset;
1976 for (j = 0; j < a->count; j++) {
1977 if (!a->type->print(s, p, field))
1978 return -ENOMEM;
1979 trace_seq_putc(s, j == a->count - 1 ? '}' : ',');
1980 p += a->type->size;
1981 }
1982 }
1983 return 0;
1984}