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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 "trace_probe.h"
15
16#undef C
17#define C(a, b) b
18
19static const char *trace_probe_err_text[] = { ERRORS };
20
21static const char *reserved_field_names[] = {
22 "common_type",
23 "common_flags",
24 "common_preempt_count",
25 "common_pid",
26 "common_tgid",
27 FIELD_STRING_IP,
28 FIELD_STRING_RETIP,
29 FIELD_STRING_FUNC,
30};
31
32/* Printing in basic type function template */
33#define DEFINE_BASIC_PRINT_TYPE_FUNC(tname, type, fmt) \
34int PRINT_TYPE_FUNC_NAME(tname)(struct trace_seq *s, void *data, void *ent)\
35{ \
36 trace_seq_printf(s, fmt, *(type *)data); \
37 return !trace_seq_has_overflowed(s); \
38} \
39const char PRINT_TYPE_FMT_NAME(tname)[] = fmt;
40
41DEFINE_BASIC_PRINT_TYPE_FUNC(u8, u8, "%u")
42DEFINE_BASIC_PRINT_TYPE_FUNC(u16, u16, "%u")
43DEFINE_BASIC_PRINT_TYPE_FUNC(u32, u32, "%u")
44DEFINE_BASIC_PRINT_TYPE_FUNC(u64, u64, "%Lu")
45DEFINE_BASIC_PRINT_TYPE_FUNC(s8, s8, "%d")
46DEFINE_BASIC_PRINT_TYPE_FUNC(s16, s16, "%d")
47DEFINE_BASIC_PRINT_TYPE_FUNC(s32, s32, "%d")
48DEFINE_BASIC_PRINT_TYPE_FUNC(s64, s64, "%Ld")
49DEFINE_BASIC_PRINT_TYPE_FUNC(x8, u8, "0x%x")
50DEFINE_BASIC_PRINT_TYPE_FUNC(x16, u16, "0x%x")
51DEFINE_BASIC_PRINT_TYPE_FUNC(x32, u32, "0x%x")
52DEFINE_BASIC_PRINT_TYPE_FUNC(x64, u64, "0x%Lx")
53
54int PRINT_TYPE_FUNC_NAME(symbol)(struct trace_seq *s, void *data, void *ent)
55{
56 trace_seq_printf(s, "%pS", (void *)*(unsigned long *)data);
57 return !trace_seq_has_overflowed(s);
58}
59const char PRINT_TYPE_FMT_NAME(symbol)[] = "%pS";
60
61/* Print type function for string type */
62int PRINT_TYPE_FUNC_NAME(string)(struct trace_seq *s, void *data, void *ent)
63{
64 int len = *(u32 *)data >> 16;
65
66 if (!len)
67 trace_seq_puts(s, "(fault)");
68 else
69 trace_seq_printf(s, "\"%s\"",
70 (const char *)get_loc_data(data, ent));
71 return !trace_seq_has_overflowed(s);
72}
73
74const char PRINT_TYPE_FMT_NAME(string)[] = "\\\"%s\\\"";
75
76/* Fetch type information table */
77static const struct fetch_type probe_fetch_types[] = {
78 /* Special types */
79 __ASSIGN_FETCH_TYPE("string", string, string, sizeof(u32), 1, 1,
80 "__data_loc char[]"),
81 __ASSIGN_FETCH_TYPE("ustring", string, string, sizeof(u32), 1, 1,
82 "__data_loc char[]"),
83 __ASSIGN_FETCH_TYPE("symstr", string, string, sizeof(u32), 1, 1,
84 "__data_loc char[]"),
85 /* Basic types */
86 ASSIGN_FETCH_TYPE(u8, u8, 0),
87 ASSIGN_FETCH_TYPE(u16, u16, 0),
88 ASSIGN_FETCH_TYPE(u32, u32, 0),
89 ASSIGN_FETCH_TYPE(u64, u64, 0),
90 ASSIGN_FETCH_TYPE(s8, u8, 1),
91 ASSIGN_FETCH_TYPE(s16, u16, 1),
92 ASSIGN_FETCH_TYPE(s32, u32, 1),
93 ASSIGN_FETCH_TYPE(s64, u64, 1),
94 ASSIGN_FETCH_TYPE_ALIAS(x8, u8, u8, 0),
95 ASSIGN_FETCH_TYPE_ALIAS(x16, u16, u16, 0),
96 ASSIGN_FETCH_TYPE_ALIAS(x32, u32, u32, 0),
97 ASSIGN_FETCH_TYPE_ALIAS(x64, u64, u64, 0),
98 ASSIGN_FETCH_TYPE_ALIAS(symbol, ADDR_FETCH_TYPE, ADDR_FETCH_TYPE, 0),
99
100 ASSIGN_FETCH_TYPE_END
101};
102
103static const struct fetch_type *find_fetch_type(const char *type, unsigned long flags)
104{
105 int i;
106
107 /* Reject the symbol/symstr for uprobes */
108 if (type && (flags & TPARG_FL_USER) &&
109 (!strcmp(type, "symbol") || !strcmp(type, "symstr")))
110 return NULL;
111
112 if (!type)
113 type = DEFAULT_FETCH_TYPE_STR;
114
115 /* Special case: bitfield */
116 if (*type == 'b') {
117 unsigned long bs;
118
119 type = strchr(type, '/');
120 if (!type)
121 goto fail;
122
123 type++;
124 if (kstrtoul(type, 0, &bs))
125 goto fail;
126
127 switch (bs) {
128 case 8:
129 return find_fetch_type("u8", flags);
130 case 16:
131 return find_fetch_type("u16", flags);
132 case 32:
133 return find_fetch_type("u32", flags);
134 case 64:
135 return find_fetch_type("u64", flags);
136 default:
137 goto fail;
138 }
139 }
140
141 for (i = 0; probe_fetch_types[i].name; i++) {
142 if (strcmp(type, probe_fetch_types[i].name) == 0)
143 return &probe_fetch_types[i];
144 }
145
146fail:
147 return NULL;
148}
149
150static struct trace_probe_log trace_probe_log;
151
152void trace_probe_log_init(const char *subsystem, int argc, const char **argv)
153{
154 trace_probe_log.subsystem = subsystem;
155 trace_probe_log.argc = argc;
156 trace_probe_log.argv = argv;
157 trace_probe_log.index = 0;
158}
159
160void trace_probe_log_clear(void)
161{
162 memset(&trace_probe_log, 0, sizeof(trace_probe_log));
163}
164
165void trace_probe_log_set_index(int index)
166{
167 trace_probe_log.index = index;
168}
169
170void __trace_probe_log_err(int offset, int err_type)
171{
172 char *command, *p;
173 int i, len = 0, pos = 0;
174
175 if (!trace_probe_log.argv)
176 return;
177
178 /* Recalculate the length and allocate buffer */
179 for (i = 0; i < trace_probe_log.argc; i++) {
180 if (i == trace_probe_log.index)
181 pos = len;
182 len += strlen(trace_probe_log.argv[i]) + 1;
183 }
184 command = kzalloc(len, GFP_KERNEL);
185 if (!command)
186 return;
187
188 if (trace_probe_log.index >= trace_probe_log.argc) {
189 /**
190 * Set the error position is next to the last arg + space.
191 * Note that len includes the terminal null and the cursor
192 * appears at pos + 1.
193 */
194 pos = len;
195 offset = 0;
196 }
197
198 /* And make a command string from argv array */
199 p = command;
200 for (i = 0; i < trace_probe_log.argc; i++) {
201 len = strlen(trace_probe_log.argv[i]);
202 strcpy(p, trace_probe_log.argv[i]);
203 p[len] = ' ';
204 p += len + 1;
205 }
206 *(p - 1) = '\0';
207
208 tracing_log_err(NULL, trace_probe_log.subsystem, command,
209 trace_probe_err_text, err_type, pos + offset);
210
211 kfree(command);
212}
213
214/* Split symbol and offset. */
215int traceprobe_split_symbol_offset(char *symbol, long *offset)
216{
217 char *tmp;
218 int ret;
219
220 if (!offset)
221 return -EINVAL;
222
223 tmp = strpbrk(symbol, "+-");
224 if (tmp) {
225 ret = kstrtol(tmp, 0, offset);
226 if (ret)
227 return ret;
228 *tmp = '\0';
229 } else
230 *offset = 0;
231
232 return 0;
233}
234
235/* @buf must has MAX_EVENT_NAME_LEN size */
236int traceprobe_parse_event_name(const char **pevent, const char **pgroup,
237 char *buf, int offset)
238{
239 const char *slash, *event = *pevent;
240 int len;
241
242 slash = strchr(event, '/');
243 if (!slash)
244 slash = strchr(event, '.');
245
246 if (slash) {
247 if (slash == event) {
248 trace_probe_log_err(offset, NO_GROUP_NAME);
249 return -EINVAL;
250 }
251 if (slash - event + 1 > MAX_EVENT_NAME_LEN) {
252 trace_probe_log_err(offset, GROUP_TOO_LONG);
253 return -EINVAL;
254 }
255 strlcpy(buf, event, slash - event + 1);
256 if (!is_good_system_name(buf)) {
257 trace_probe_log_err(offset, BAD_GROUP_NAME);
258 return -EINVAL;
259 }
260 *pgroup = buf;
261 *pevent = slash + 1;
262 offset += slash - event + 1;
263 event = *pevent;
264 }
265 len = strlen(event);
266 if (len == 0) {
267 if (slash) {
268 *pevent = NULL;
269 return 0;
270 }
271 trace_probe_log_err(offset, NO_EVENT_NAME);
272 return -EINVAL;
273 } else if (len > MAX_EVENT_NAME_LEN) {
274 trace_probe_log_err(offset, EVENT_TOO_LONG);
275 return -EINVAL;
276 }
277 if (!is_good_name(event)) {
278 trace_probe_log_err(offset, BAD_EVENT_NAME);
279 return -EINVAL;
280 }
281 return 0;
282}
283
284#define PARAM_MAX_STACK (THREAD_SIZE / sizeof(unsigned long))
285
286static int parse_probe_vars(char *arg, const struct fetch_type *t,
287 struct fetch_insn *code, unsigned int flags, int offs)
288{
289 unsigned long param;
290 int ret = 0;
291 int len;
292
293 if (flags & TPARG_FL_TPOINT) {
294 if (code->data)
295 return -EFAULT;
296 code->data = kstrdup(arg, GFP_KERNEL);
297 if (!code->data)
298 return -ENOMEM;
299 code->op = FETCH_OP_TP_ARG;
300 } else if (strcmp(arg, "retval") == 0) {
301 if (flags & TPARG_FL_RETURN) {
302 code->op = FETCH_OP_RETVAL;
303 } else {
304 trace_probe_log_err(offs, RETVAL_ON_PROBE);
305 ret = -EINVAL;
306 }
307 } else if ((len = str_has_prefix(arg, "stack"))) {
308 if (arg[len] == '\0') {
309 code->op = FETCH_OP_STACKP;
310 } else if (isdigit(arg[len])) {
311 ret = kstrtoul(arg + len, 10, ¶m);
312 if (ret) {
313 goto inval_var;
314 } else if ((flags & TPARG_FL_KERNEL) &&
315 param > PARAM_MAX_STACK) {
316 trace_probe_log_err(offs, BAD_STACK_NUM);
317 ret = -EINVAL;
318 } else {
319 code->op = FETCH_OP_STACK;
320 code->param = (unsigned int)param;
321 }
322 } else
323 goto inval_var;
324 } else if (strcmp(arg, "comm") == 0 || strcmp(arg, "COMM") == 0) {
325 code->op = FETCH_OP_COMM;
326#ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API
327 } else if (((flags & TPARG_FL_MASK) ==
328 (TPARG_FL_KERNEL | TPARG_FL_FENTRY)) &&
329 (len = str_has_prefix(arg, "arg"))) {
330 ret = kstrtoul(arg + len, 10, ¶m);
331 if (ret) {
332 goto inval_var;
333 } else if (!param || param > PARAM_MAX_STACK) {
334 trace_probe_log_err(offs, BAD_ARG_NUM);
335 return -EINVAL;
336 }
337 code->op = FETCH_OP_ARG;
338 code->param = (unsigned int)param - 1;
339#endif
340 } else
341 goto inval_var;
342
343 return ret;
344
345inval_var:
346 trace_probe_log_err(offs, BAD_VAR);
347 return -EINVAL;
348}
349
350static int str_to_immediate(char *str, unsigned long *imm)
351{
352 if (isdigit(str[0]))
353 return kstrtoul(str, 0, imm);
354 else if (str[0] == '-')
355 return kstrtol(str, 0, (long *)imm);
356 else if (str[0] == '+')
357 return kstrtol(str + 1, 0, (long *)imm);
358 return -EINVAL;
359}
360
361static int __parse_imm_string(char *str, char **pbuf, int offs)
362{
363 size_t len = strlen(str);
364
365 if (str[len - 1] != '"') {
366 trace_probe_log_err(offs + len, IMMSTR_NO_CLOSE);
367 return -EINVAL;
368 }
369 *pbuf = kstrndup(str, len - 1, GFP_KERNEL);
370 if (!*pbuf)
371 return -ENOMEM;
372 return 0;
373}
374
375/* Recursive argument parser */
376static int
377parse_probe_arg(char *arg, const struct fetch_type *type,
378 struct fetch_insn **pcode, struct fetch_insn *end,
379 unsigned int flags, int offs)
380{
381 struct fetch_insn *code = *pcode;
382 unsigned long param;
383 int deref = FETCH_OP_DEREF;
384 long offset = 0;
385 char *tmp;
386 int ret = 0;
387
388 switch (arg[0]) {
389 case '$':
390 ret = parse_probe_vars(arg + 1, type, code, flags, offs);
391 break;
392
393 case '%': /* named register */
394 if (flags & TPARG_FL_TPOINT) {
395 /* eprobes do not handle registers */
396 trace_probe_log_err(offs, BAD_VAR);
397 break;
398 }
399 ret = regs_query_register_offset(arg + 1);
400 if (ret >= 0) {
401 code->op = FETCH_OP_REG;
402 code->param = (unsigned int)ret;
403 ret = 0;
404 } else
405 trace_probe_log_err(offs, BAD_REG_NAME);
406 break;
407
408 case '@': /* memory, file-offset or symbol */
409 if (isdigit(arg[1])) {
410 ret = kstrtoul(arg + 1, 0, ¶m);
411 if (ret) {
412 trace_probe_log_err(offs, BAD_MEM_ADDR);
413 break;
414 }
415 /* load address */
416 code->op = FETCH_OP_IMM;
417 code->immediate = param;
418 } else if (arg[1] == '+') {
419 /* kprobes don't support file offsets */
420 if (flags & TPARG_FL_KERNEL) {
421 trace_probe_log_err(offs, FILE_ON_KPROBE);
422 return -EINVAL;
423 }
424 ret = kstrtol(arg + 2, 0, &offset);
425 if (ret) {
426 trace_probe_log_err(offs, BAD_FILE_OFFS);
427 break;
428 }
429
430 code->op = FETCH_OP_FOFFS;
431 code->immediate = (unsigned long)offset; // imm64?
432 } else {
433 /* uprobes don't support symbols */
434 if (!(flags & TPARG_FL_KERNEL)) {
435 trace_probe_log_err(offs, SYM_ON_UPROBE);
436 return -EINVAL;
437 }
438 /* Preserve symbol for updating */
439 code->op = FETCH_NOP_SYMBOL;
440 code->data = kstrdup(arg + 1, GFP_KERNEL);
441 if (!code->data)
442 return -ENOMEM;
443 if (++code == end) {
444 trace_probe_log_err(offs, TOO_MANY_OPS);
445 return -EINVAL;
446 }
447 code->op = FETCH_OP_IMM;
448 code->immediate = 0;
449 }
450 /* These are fetching from memory */
451 if (++code == end) {
452 trace_probe_log_err(offs, TOO_MANY_OPS);
453 return -EINVAL;
454 }
455 *pcode = code;
456 code->op = FETCH_OP_DEREF;
457 code->offset = offset;
458 break;
459
460 case '+': /* deref memory */
461 case '-':
462 if (arg[1] == 'u') {
463 deref = FETCH_OP_UDEREF;
464 arg[1] = arg[0];
465 arg++;
466 }
467 if (arg[0] == '+')
468 arg++; /* Skip '+', because kstrtol() rejects it. */
469 tmp = strchr(arg, '(');
470 if (!tmp) {
471 trace_probe_log_err(offs, DEREF_NEED_BRACE);
472 return -EINVAL;
473 }
474 *tmp = '\0';
475 ret = kstrtol(arg, 0, &offset);
476 if (ret) {
477 trace_probe_log_err(offs, BAD_DEREF_OFFS);
478 break;
479 }
480 offs += (tmp + 1 - arg) + (arg[0] != '-' ? 1 : 0);
481 arg = tmp + 1;
482 tmp = strrchr(arg, ')');
483 if (!tmp) {
484 trace_probe_log_err(offs + strlen(arg),
485 DEREF_OPEN_BRACE);
486 return -EINVAL;
487 } else {
488 const struct fetch_type *t2 = find_fetch_type(NULL, flags);
489
490 *tmp = '\0';
491 ret = parse_probe_arg(arg, t2, &code, end, flags, offs);
492 if (ret)
493 break;
494 if (code->op == FETCH_OP_COMM ||
495 code->op == FETCH_OP_DATA) {
496 trace_probe_log_err(offs, COMM_CANT_DEREF);
497 return -EINVAL;
498 }
499 if (++code == end) {
500 trace_probe_log_err(offs, TOO_MANY_OPS);
501 return -EINVAL;
502 }
503 *pcode = code;
504
505 code->op = deref;
506 code->offset = offset;
507 }
508 break;
509 case '\\': /* Immediate value */
510 if (arg[1] == '"') { /* Immediate string */
511 ret = __parse_imm_string(arg + 2, &tmp, offs + 2);
512 if (ret)
513 break;
514 code->op = FETCH_OP_DATA;
515 code->data = tmp;
516 } else {
517 ret = str_to_immediate(arg + 1, &code->immediate);
518 if (ret)
519 trace_probe_log_err(offs + 1, BAD_IMM);
520 else
521 code->op = FETCH_OP_IMM;
522 }
523 break;
524 }
525 if (!ret && code->op == FETCH_OP_NOP) {
526 /* Parsed, but do not find fetch method */
527 trace_probe_log_err(offs, BAD_FETCH_ARG);
528 ret = -EINVAL;
529 }
530 return ret;
531}
532
533#define BYTES_TO_BITS(nb) ((BITS_PER_LONG * (nb)) / sizeof(long))
534
535/* Bitfield type needs to be parsed into a fetch function */
536static int __parse_bitfield_probe_arg(const char *bf,
537 const struct fetch_type *t,
538 struct fetch_insn **pcode)
539{
540 struct fetch_insn *code = *pcode;
541 unsigned long bw, bo;
542 char *tail;
543
544 if (*bf != 'b')
545 return 0;
546
547 bw = simple_strtoul(bf + 1, &tail, 0); /* Use simple one */
548
549 if (bw == 0 || *tail != '@')
550 return -EINVAL;
551
552 bf = tail + 1;
553 bo = simple_strtoul(bf, &tail, 0);
554
555 if (tail == bf || *tail != '/')
556 return -EINVAL;
557 code++;
558 if (code->op != FETCH_OP_NOP)
559 return -EINVAL;
560 *pcode = code;
561
562 code->op = FETCH_OP_MOD_BF;
563 code->lshift = BYTES_TO_BITS(t->size) - (bw + bo);
564 code->rshift = BYTES_TO_BITS(t->size) - bw;
565 code->basesize = t->size;
566
567 return (BYTES_TO_BITS(t->size) < (bw + bo)) ? -EINVAL : 0;
568}
569
570/* String length checking wrapper */
571static int traceprobe_parse_probe_arg_body(const char *argv, ssize_t *size,
572 struct probe_arg *parg, unsigned int flags, int offset)
573{
574 struct fetch_insn *code, *scode, *tmp = NULL;
575 char *t, *t2, *t3;
576 char *arg;
577 int ret, len;
578
579 arg = kstrdup(argv, GFP_KERNEL);
580 if (!arg)
581 return -ENOMEM;
582
583 ret = -EINVAL;
584 len = strlen(arg);
585 if (len > MAX_ARGSTR_LEN) {
586 trace_probe_log_err(offset, ARG_TOO_LONG);
587 goto out;
588 } else if (len == 0) {
589 trace_probe_log_err(offset, NO_ARG_BODY);
590 goto out;
591 }
592
593 ret = -ENOMEM;
594 parg->comm = kstrdup(arg, GFP_KERNEL);
595 if (!parg->comm)
596 goto out;
597
598 ret = -EINVAL;
599 t = strchr(arg, ':');
600 if (t) {
601 *t = '\0';
602 t2 = strchr(++t, '[');
603 if (t2) {
604 *t2++ = '\0';
605 t3 = strchr(t2, ']');
606 if (!t3) {
607 offset += t2 + strlen(t2) - arg;
608 trace_probe_log_err(offset,
609 ARRAY_NO_CLOSE);
610 goto out;
611 } else if (t3[1] != '\0') {
612 trace_probe_log_err(offset + t3 + 1 - arg,
613 BAD_ARRAY_SUFFIX);
614 goto out;
615 }
616 *t3 = '\0';
617 if (kstrtouint(t2, 0, &parg->count) || !parg->count) {
618 trace_probe_log_err(offset + t2 - arg,
619 BAD_ARRAY_NUM);
620 goto out;
621 }
622 if (parg->count > MAX_ARRAY_LEN) {
623 trace_probe_log_err(offset + t2 - arg,
624 ARRAY_TOO_BIG);
625 goto out;
626 }
627 }
628 }
629
630 /*
631 * Since $comm and immediate string can not be dereferenced,
632 * we can find those by strcmp. But ignore for eprobes.
633 */
634 if (!(flags & TPARG_FL_TPOINT) &&
635 (strcmp(arg, "$comm") == 0 || strcmp(arg, "$COMM") == 0 ||
636 strncmp(arg, "\\\"", 2) == 0)) {
637 /* The type of $comm must be "string", and not an array. */
638 if (parg->count || (t && strcmp(t, "string")))
639 goto out;
640 parg->type = find_fetch_type("string", flags);
641 } else
642 parg->type = find_fetch_type(t, flags);
643 if (!parg->type) {
644 trace_probe_log_err(offset + (t ? (t - arg) : 0), BAD_TYPE);
645 goto out;
646 }
647 parg->offset = *size;
648 *size += parg->type->size * (parg->count ?: 1);
649
650 ret = -ENOMEM;
651 if (parg->count) {
652 len = strlen(parg->type->fmttype) + 6;
653 parg->fmt = kmalloc(len, GFP_KERNEL);
654 if (!parg->fmt)
655 goto out;
656 snprintf(parg->fmt, len, "%s[%d]", parg->type->fmttype,
657 parg->count);
658 }
659
660 code = tmp = kcalloc(FETCH_INSN_MAX, sizeof(*code), GFP_KERNEL);
661 if (!code)
662 goto out;
663 code[FETCH_INSN_MAX - 1].op = FETCH_OP_END;
664
665 ret = parse_probe_arg(arg, parg->type, &code, &code[FETCH_INSN_MAX - 1],
666 flags, offset);
667 if (ret)
668 goto fail;
669
670 ret = -EINVAL;
671 /* Store operation */
672 if (parg->type->is_string) {
673 if (!strcmp(parg->type->name, "symstr")) {
674 if (code->op != FETCH_OP_REG && code->op != FETCH_OP_STACK &&
675 code->op != FETCH_OP_RETVAL && code->op != FETCH_OP_ARG &&
676 code->op != FETCH_OP_DEREF && code->op != FETCH_OP_TP_ARG) {
677 trace_probe_log_err(offset + (t ? (t - arg) : 0),
678 BAD_SYMSTRING);
679 goto fail;
680 }
681 } else {
682 if (code->op != FETCH_OP_DEREF && code->op != FETCH_OP_UDEREF &&
683 code->op != FETCH_OP_IMM && code->op != FETCH_OP_COMM &&
684 code->op != FETCH_OP_DATA && code->op != FETCH_OP_TP_ARG) {
685 trace_probe_log_err(offset + (t ? (t - arg) : 0),
686 BAD_STRING);
687 goto fail;
688 }
689 }
690 if (!strcmp(parg->type->name, "symstr") ||
691 (code->op == FETCH_OP_IMM || code->op == FETCH_OP_COMM ||
692 code->op == FETCH_OP_DATA) || code->op == FETCH_OP_TP_ARG ||
693 parg->count) {
694 /*
695 * IMM, DATA and COMM is pointing actual address, those
696 * must be kept, and if parg->count != 0, this is an
697 * array of string pointers instead of string address
698 * itself.
699 * For the symstr, it doesn't need to dereference, thus
700 * it just get the value.
701 */
702 code++;
703 if (code->op != FETCH_OP_NOP) {
704 trace_probe_log_err(offset, TOO_MANY_OPS);
705 goto fail;
706 }
707 }
708 /* If op == DEREF, replace it with STRING */
709 if (!strcmp(parg->type->name, "ustring") ||
710 code->op == FETCH_OP_UDEREF)
711 code->op = FETCH_OP_ST_USTRING;
712 else if (!strcmp(parg->type->name, "symstr"))
713 code->op = FETCH_OP_ST_SYMSTR;
714 else
715 code->op = FETCH_OP_ST_STRING;
716 code->size = parg->type->size;
717 parg->dynamic = true;
718 } else if (code->op == FETCH_OP_DEREF) {
719 code->op = FETCH_OP_ST_MEM;
720 code->size = parg->type->size;
721 } else if (code->op == FETCH_OP_UDEREF) {
722 code->op = FETCH_OP_ST_UMEM;
723 code->size = parg->type->size;
724 } else {
725 code++;
726 if (code->op != FETCH_OP_NOP) {
727 trace_probe_log_err(offset, TOO_MANY_OPS);
728 goto fail;
729 }
730 code->op = FETCH_OP_ST_RAW;
731 code->size = parg->type->size;
732 }
733 scode = code;
734 /* Modify operation */
735 if (t != NULL) {
736 ret = __parse_bitfield_probe_arg(t, parg->type, &code);
737 if (ret) {
738 trace_probe_log_err(offset + t - arg, BAD_BITFIELD);
739 goto fail;
740 }
741 }
742 ret = -EINVAL;
743 /* Loop(Array) operation */
744 if (parg->count) {
745 if (scode->op != FETCH_OP_ST_MEM &&
746 scode->op != FETCH_OP_ST_STRING &&
747 scode->op != FETCH_OP_ST_USTRING) {
748 trace_probe_log_err(offset + (t ? (t - arg) : 0),
749 BAD_STRING);
750 goto fail;
751 }
752 code++;
753 if (code->op != FETCH_OP_NOP) {
754 trace_probe_log_err(offset, TOO_MANY_OPS);
755 goto fail;
756 }
757 code->op = FETCH_OP_LP_ARRAY;
758 code->param = parg->count;
759 }
760 code++;
761 code->op = FETCH_OP_END;
762
763 ret = 0;
764 /* Shrink down the code buffer */
765 parg->code = kcalloc(code - tmp + 1, sizeof(*code), GFP_KERNEL);
766 if (!parg->code)
767 ret = -ENOMEM;
768 else
769 memcpy(parg->code, tmp, sizeof(*code) * (code - tmp + 1));
770
771fail:
772 if (ret) {
773 for (code = tmp; code < tmp + FETCH_INSN_MAX; code++)
774 if (code->op == FETCH_NOP_SYMBOL ||
775 code->op == FETCH_OP_DATA)
776 kfree(code->data);
777 }
778 kfree(tmp);
779out:
780 kfree(arg);
781
782 return ret;
783}
784
785/* Return 1 if name is reserved or already used by another argument */
786static int traceprobe_conflict_field_name(const char *name,
787 struct probe_arg *args, int narg)
788{
789 int i;
790
791 for (i = 0; i < ARRAY_SIZE(reserved_field_names); i++)
792 if (strcmp(reserved_field_names[i], name) == 0)
793 return 1;
794
795 for (i = 0; i < narg; i++)
796 if (strcmp(args[i].name, name) == 0)
797 return 1;
798
799 return 0;
800}
801
802int traceprobe_parse_probe_arg(struct trace_probe *tp, int i, const char *arg,
803 unsigned int flags)
804{
805 struct probe_arg *parg = &tp->args[i];
806 const char *body;
807
808 /* Increment count for freeing args in error case */
809 tp->nr_args++;
810
811 body = strchr(arg, '=');
812 if (body) {
813 if (body - arg > MAX_ARG_NAME_LEN) {
814 trace_probe_log_err(0, ARG_NAME_TOO_LONG);
815 return -EINVAL;
816 } else if (body == arg) {
817 trace_probe_log_err(0, NO_ARG_NAME);
818 return -EINVAL;
819 }
820 parg->name = kmemdup_nul(arg, body - arg, GFP_KERNEL);
821 body++;
822 } else {
823 /* If argument name is omitted, set "argN" */
824 parg->name = kasprintf(GFP_KERNEL, "arg%d", i + 1);
825 body = arg;
826 }
827 if (!parg->name)
828 return -ENOMEM;
829
830 if (!is_good_name(parg->name)) {
831 trace_probe_log_err(0, BAD_ARG_NAME);
832 return -EINVAL;
833 }
834 if (traceprobe_conflict_field_name(parg->name, tp->args, i)) {
835 trace_probe_log_err(0, USED_ARG_NAME);
836 return -EINVAL;
837 }
838 /* Parse fetch argument */
839 return traceprobe_parse_probe_arg_body(body, &tp->size, parg, flags,
840 body - arg);
841}
842
843void traceprobe_free_probe_arg(struct probe_arg *arg)
844{
845 struct fetch_insn *code = arg->code;
846
847 while (code && code->op != FETCH_OP_END) {
848 if (code->op == FETCH_NOP_SYMBOL ||
849 code->op == FETCH_OP_DATA)
850 kfree(code->data);
851 code++;
852 }
853 kfree(arg->code);
854 kfree(arg->name);
855 kfree(arg->comm);
856 kfree(arg->fmt);
857}
858
859int traceprobe_update_arg(struct probe_arg *arg)
860{
861 struct fetch_insn *code = arg->code;
862 long offset;
863 char *tmp;
864 char c;
865 int ret = 0;
866
867 while (code && code->op != FETCH_OP_END) {
868 if (code->op == FETCH_NOP_SYMBOL) {
869 if (code[1].op != FETCH_OP_IMM)
870 return -EINVAL;
871
872 tmp = strpbrk(code->data, "+-");
873 if (tmp)
874 c = *tmp;
875 ret = traceprobe_split_symbol_offset(code->data,
876 &offset);
877 if (ret)
878 return ret;
879
880 code[1].immediate =
881 (unsigned long)kallsyms_lookup_name(code->data);
882 if (tmp)
883 *tmp = c;
884 if (!code[1].immediate)
885 return -ENOENT;
886 code[1].immediate += offset;
887 }
888 code++;
889 }
890 return 0;
891}
892
893/* When len=0, we just calculate the needed length */
894#define LEN_OR_ZERO (len ? len - pos : 0)
895static int __set_print_fmt(struct trace_probe *tp, char *buf, int len,
896 enum probe_print_type ptype)
897{
898 struct probe_arg *parg;
899 int i, j;
900 int pos = 0;
901 const char *fmt, *arg;
902
903 switch (ptype) {
904 case PROBE_PRINT_NORMAL:
905 fmt = "(%lx)";
906 arg = ", REC->" FIELD_STRING_IP;
907 break;
908 case PROBE_PRINT_RETURN:
909 fmt = "(%lx <- %lx)";
910 arg = ", REC->" FIELD_STRING_FUNC ", REC->" FIELD_STRING_RETIP;
911 break;
912 case PROBE_PRINT_EVENT:
913 fmt = "";
914 arg = "";
915 break;
916 default:
917 WARN_ON_ONCE(1);
918 return 0;
919 }
920
921 pos += snprintf(buf + pos, LEN_OR_ZERO, "\"%s", fmt);
922
923 for (i = 0; i < tp->nr_args; i++) {
924 parg = tp->args + i;
925 pos += snprintf(buf + pos, LEN_OR_ZERO, " %s=", parg->name);
926 if (parg->count) {
927 pos += snprintf(buf + pos, LEN_OR_ZERO, "{%s",
928 parg->type->fmt);
929 for (j = 1; j < parg->count; j++)
930 pos += snprintf(buf + pos, LEN_OR_ZERO, ",%s",
931 parg->type->fmt);
932 pos += snprintf(buf + pos, LEN_OR_ZERO, "}");
933 } else
934 pos += snprintf(buf + pos, LEN_OR_ZERO, "%s",
935 parg->type->fmt);
936 }
937
938 pos += snprintf(buf + pos, LEN_OR_ZERO, "\"%s", arg);
939
940 for (i = 0; i < tp->nr_args; i++) {
941 parg = tp->args + i;
942 if (parg->count) {
943 if (parg->type->is_string)
944 fmt = ", __get_str(%s[%d])";
945 else
946 fmt = ", REC->%s[%d]";
947 for (j = 0; j < parg->count; j++)
948 pos += snprintf(buf + pos, LEN_OR_ZERO,
949 fmt, parg->name, j);
950 } else {
951 if (parg->type->is_string)
952 fmt = ", __get_str(%s)";
953 else
954 fmt = ", REC->%s";
955 pos += snprintf(buf + pos, LEN_OR_ZERO,
956 fmt, parg->name);
957 }
958 }
959
960 /* return the length of print_fmt */
961 return pos;
962}
963#undef LEN_OR_ZERO
964
965int traceprobe_set_print_fmt(struct trace_probe *tp, enum probe_print_type ptype)
966{
967 struct trace_event_call *call = trace_probe_event_call(tp);
968 int len;
969 char *print_fmt;
970
971 /* First: called with 0 length to calculate the needed length */
972 len = __set_print_fmt(tp, NULL, 0, ptype);
973 print_fmt = kmalloc(len + 1, GFP_KERNEL);
974 if (!print_fmt)
975 return -ENOMEM;
976
977 /* Second: actually write the @print_fmt */
978 __set_print_fmt(tp, print_fmt, len + 1, ptype);
979 call->print_fmt = print_fmt;
980
981 return 0;
982}
983
984int traceprobe_define_arg_fields(struct trace_event_call *event_call,
985 size_t offset, struct trace_probe *tp)
986{
987 int ret, i;
988
989 /* Set argument names as fields */
990 for (i = 0; i < tp->nr_args; i++) {
991 struct probe_arg *parg = &tp->args[i];
992 const char *fmt = parg->type->fmttype;
993 int size = parg->type->size;
994
995 if (parg->fmt)
996 fmt = parg->fmt;
997 if (parg->count)
998 size *= parg->count;
999 ret = trace_define_field(event_call, fmt, parg->name,
1000 offset + parg->offset, size,
1001 parg->type->is_signed,
1002 FILTER_OTHER);
1003 if (ret)
1004 return ret;
1005 }
1006 return 0;
1007}
1008
1009static void trace_probe_event_free(struct trace_probe_event *tpe)
1010{
1011 kfree(tpe->class.system);
1012 kfree(tpe->call.name);
1013 kfree(tpe->call.print_fmt);
1014 kfree(tpe);
1015}
1016
1017int trace_probe_append(struct trace_probe *tp, struct trace_probe *to)
1018{
1019 if (trace_probe_has_sibling(tp))
1020 return -EBUSY;
1021
1022 list_del_init(&tp->list);
1023 trace_probe_event_free(tp->event);
1024
1025 tp->event = to->event;
1026 list_add_tail(&tp->list, trace_probe_probe_list(to));
1027
1028 return 0;
1029}
1030
1031void trace_probe_unlink(struct trace_probe *tp)
1032{
1033 list_del_init(&tp->list);
1034 if (list_empty(trace_probe_probe_list(tp)))
1035 trace_probe_event_free(tp->event);
1036 tp->event = NULL;
1037}
1038
1039void trace_probe_cleanup(struct trace_probe *tp)
1040{
1041 int i;
1042
1043 for (i = 0; i < tp->nr_args; i++)
1044 traceprobe_free_probe_arg(&tp->args[i]);
1045
1046 if (tp->event)
1047 trace_probe_unlink(tp);
1048}
1049
1050int trace_probe_init(struct trace_probe *tp, const char *event,
1051 const char *group, bool alloc_filter)
1052{
1053 struct trace_event_call *call;
1054 size_t size = sizeof(struct trace_probe_event);
1055 int ret = 0;
1056
1057 if (!event || !group)
1058 return -EINVAL;
1059
1060 if (alloc_filter)
1061 size += sizeof(struct trace_uprobe_filter);
1062
1063 tp->event = kzalloc(size, GFP_KERNEL);
1064 if (!tp->event)
1065 return -ENOMEM;
1066
1067 INIT_LIST_HEAD(&tp->event->files);
1068 INIT_LIST_HEAD(&tp->event->class.fields);
1069 INIT_LIST_HEAD(&tp->event->probes);
1070 INIT_LIST_HEAD(&tp->list);
1071 list_add(&tp->list, &tp->event->probes);
1072
1073 call = trace_probe_event_call(tp);
1074 call->class = &tp->event->class;
1075 call->name = kstrdup(event, GFP_KERNEL);
1076 if (!call->name) {
1077 ret = -ENOMEM;
1078 goto error;
1079 }
1080
1081 tp->event->class.system = kstrdup(group, GFP_KERNEL);
1082 if (!tp->event->class.system) {
1083 ret = -ENOMEM;
1084 goto error;
1085 }
1086
1087 return 0;
1088
1089error:
1090 trace_probe_cleanup(tp);
1091 return ret;
1092}
1093
1094static struct trace_event_call *
1095find_trace_event_call(const char *system, const char *event_name)
1096{
1097 struct trace_event_call *tp_event;
1098 const char *name;
1099
1100 list_for_each_entry(tp_event, &ftrace_events, list) {
1101 if (!tp_event->class->system ||
1102 strcmp(system, tp_event->class->system))
1103 continue;
1104 name = trace_event_name(tp_event);
1105 if (!name || strcmp(event_name, name))
1106 continue;
1107 return tp_event;
1108 }
1109
1110 return NULL;
1111}
1112
1113int trace_probe_register_event_call(struct trace_probe *tp)
1114{
1115 struct trace_event_call *call = trace_probe_event_call(tp);
1116 int ret;
1117
1118 lockdep_assert_held(&event_mutex);
1119
1120 if (find_trace_event_call(trace_probe_group_name(tp),
1121 trace_probe_name(tp)))
1122 return -EEXIST;
1123
1124 ret = register_trace_event(&call->event);
1125 if (!ret)
1126 return -ENODEV;
1127
1128 ret = trace_add_event_call(call);
1129 if (ret)
1130 unregister_trace_event(&call->event);
1131
1132 return ret;
1133}
1134
1135int trace_probe_add_file(struct trace_probe *tp, struct trace_event_file *file)
1136{
1137 struct event_file_link *link;
1138
1139 link = kmalloc(sizeof(*link), GFP_KERNEL);
1140 if (!link)
1141 return -ENOMEM;
1142
1143 link->file = file;
1144 INIT_LIST_HEAD(&link->list);
1145 list_add_tail_rcu(&link->list, &tp->event->files);
1146 trace_probe_set_flag(tp, TP_FLAG_TRACE);
1147 return 0;
1148}
1149
1150struct event_file_link *trace_probe_get_file_link(struct trace_probe *tp,
1151 struct trace_event_file *file)
1152{
1153 struct event_file_link *link;
1154
1155 trace_probe_for_each_link(link, tp) {
1156 if (link->file == file)
1157 return link;
1158 }
1159
1160 return NULL;
1161}
1162
1163int trace_probe_remove_file(struct trace_probe *tp,
1164 struct trace_event_file *file)
1165{
1166 struct event_file_link *link;
1167
1168 link = trace_probe_get_file_link(tp, file);
1169 if (!link)
1170 return -ENOENT;
1171
1172 list_del_rcu(&link->list);
1173 kvfree_rcu(link);
1174
1175 if (list_empty(&tp->event->files))
1176 trace_probe_clear_flag(tp, TP_FLAG_TRACE);
1177
1178 return 0;
1179}
1180
1181/*
1182 * Return the smallest index of different type argument (start from 1).
1183 * If all argument types and name are same, return 0.
1184 */
1185int trace_probe_compare_arg_type(struct trace_probe *a, struct trace_probe *b)
1186{
1187 int i;
1188
1189 /* In case of more arguments */
1190 if (a->nr_args < b->nr_args)
1191 return a->nr_args + 1;
1192 if (a->nr_args > b->nr_args)
1193 return b->nr_args + 1;
1194
1195 for (i = 0; i < a->nr_args; i++) {
1196 if ((b->nr_args <= i) ||
1197 ((a->args[i].type != b->args[i].type) ||
1198 (a->args[i].count != b->args[i].count) ||
1199 strcmp(a->args[i].name, b->args[i].name)))
1200 return i + 1;
1201 }
1202
1203 return 0;
1204}
1205
1206bool trace_probe_match_command_args(struct trace_probe *tp,
1207 int argc, const char **argv)
1208{
1209 char buf[MAX_ARGSTR_LEN + 1];
1210 int i;
1211
1212 if (tp->nr_args < argc)
1213 return false;
1214
1215 for (i = 0; i < argc; i++) {
1216 snprintf(buf, sizeof(buf), "%s=%s",
1217 tp->args[i].name, tp->args[i].comm);
1218 if (strcmp(buf, argv[i]))
1219 return false;
1220 }
1221 return true;
1222}
1223
1224int trace_probe_create(const char *raw_command, int (*createfn)(int, const char **))
1225{
1226 int argc = 0, ret = 0;
1227 char **argv;
1228
1229 argv = argv_split(GFP_KERNEL, raw_command, &argc);
1230 if (!argv)
1231 return -ENOMEM;
1232
1233 if (argc)
1234 ret = createfn(argc, (const char **)argv);
1235
1236 argv_free(argv);
1237
1238 return ret;
1239}
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 "trace_probe.h"
15
16#undef C
17#define C(a, b) b
18
19static const char *trace_probe_err_text[] = { ERRORS };
20
21static const char *reserved_field_names[] = {
22 "common_type",
23 "common_flags",
24 "common_preempt_count",
25 "common_pid",
26 "common_tgid",
27 FIELD_STRING_IP,
28 FIELD_STRING_RETIP,
29 FIELD_STRING_FUNC,
30};
31
32/* Printing in basic type function template */
33#define DEFINE_BASIC_PRINT_TYPE_FUNC(tname, type, fmt) \
34int PRINT_TYPE_FUNC_NAME(tname)(struct trace_seq *s, void *data, void *ent)\
35{ \
36 trace_seq_printf(s, fmt, *(type *)data); \
37 return !trace_seq_has_overflowed(s); \
38} \
39const char PRINT_TYPE_FMT_NAME(tname)[] = fmt;
40
41DEFINE_BASIC_PRINT_TYPE_FUNC(u8, u8, "%u")
42DEFINE_BASIC_PRINT_TYPE_FUNC(u16, u16, "%u")
43DEFINE_BASIC_PRINT_TYPE_FUNC(u32, u32, "%u")
44DEFINE_BASIC_PRINT_TYPE_FUNC(u64, u64, "%Lu")
45DEFINE_BASIC_PRINT_TYPE_FUNC(s8, s8, "%d")
46DEFINE_BASIC_PRINT_TYPE_FUNC(s16, s16, "%d")
47DEFINE_BASIC_PRINT_TYPE_FUNC(s32, s32, "%d")
48DEFINE_BASIC_PRINT_TYPE_FUNC(s64, s64, "%Ld")
49DEFINE_BASIC_PRINT_TYPE_FUNC(x8, u8, "0x%x")
50DEFINE_BASIC_PRINT_TYPE_FUNC(x16, u16, "0x%x")
51DEFINE_BASIC_PRINT_TYPE_FUNC(x32, u32, "0x%x")
52DEFINE_BASIC_PRINT_TYPE_FUNC(x64, u64, "0x%Lx")
53
54int PRINT_TYPE_FUNC_NAME(symbol)(struct trace_seq *s, void *data, void *ent)
55{
56 trace_seq_printf(s, "%pS", (void *)*(unsigned long *)data);
57 return !trace_seq_has_overflowed(s);
58}
59const char PRINT_TYPE_FMT_NAME(symbol)[] = "%pS";
60
61/* Print type function for string type */
62int PRINT_TYPE_FUNC_NAME(string)(struct trace_seq *s, void *data, void *ent)
63{
64 int len = *(u32 *)data >> 16;
65
66 if (!len)
67 trace_seq_puts(s, "(fault)");
68 else
69 trace_seq_printf(s, "\"%s\"",
70 (const char *)get_loc_data(data, ent));
71 return !trace_seq_has_overflowed(s);
72}
73
74const char PRINT_TYPE_FMT_NAME(string)[] = "\\\"%s\\\"";
75
76/* Fetch type information table */
77static const struct fetch_type probe_fetch_types[] = {
78 /* Special types */
79 __ASSIGN_FETCH_TYPE("string", string, string, sizeof(u32), 1,
80 "__data_loc char[]"),
81 __ASSIGN_FETCH_TYPE("ustring", string, string, sizeof(u32), 1,
82 "__data_loc char[]"),
83 /* Basic types */
84 ASSIGN_FETCH_TYPE(u8, u8, 0),
85 ASSIGN_FETCH_TYPE(u16, u16, 0),
86 ASSIGN_FETCH_TYPE(u32, u32, 0),
87 ASSIGN_FETCH_TYPE(u64, u64, 0),
88 ASSIGN_FETCH_TYPE(s8, u8, 1),
89 ASSIGN_FETCH_TYPE(s16, u16, 1),
90 ASSIGN_FETCH_TYPE(s32, u32, 1),
91 ASSIGN_FETCH_TYPE(s64, u64, 1),
92 ASSIGN_FETCH_TYPE_ALIAS(x8, u8, u8, 0),
93 ASSIGN_FETCH_TYPE_ALIAS(x16, u16, u16, 0),
94 ASSIGN_FETCH_TYPE_ALIAS(x32, u32, u32, 0),
95 ASSIGN_FETCH_TYPE_ALIAS(x64, u64, u64, 0),
96 ASSIGN_FETCH_TYPE_ALIAS(symbol, ADDR_FETCH_TYPE, ADDR_FETCH_TYPE, 0),
97
98 ASSIGN_FETCH_TYPE_END
99};
100
101static const struct fetch_type *find_fetch_type(const char *type)
102{
103 int i;
104
105 if (!type)
106 type = DEFAULT_FETCH_TYPE_STR;
107
108 /* Special case: bitfield */
109 if (*type == 'b') {
110 unsigned long bs;
111
112 type = strchr(type, '/');
113 if (!type)
114 goto fail;
115
116 type++;
117 if (kstrtoul(type, 0, &bs))
118 goto fail;
119
120 switch (bs) {
121 case 8:
122 return find_fetch_type("u8");
123 case 16:
124 return find_fetch_type("u16");
125 case 32:
126 return find_fetch_type("u32");
127 case 64:
128 return find_fetch_type("u64");
129 default:
130 goto fail;
131 }
132 }
133
134 for (i = 0; probe_fetch_types[i].name; i++) {
135 if (strcmp(type, probe_fetch_types[i].name) == 0)
136 return &probe_fetch_types[i];
137 }
138
139fail:
140 return NULL;
141}
142
143static struct trace_probe_log trace_probe_log;
144
145void trace_probe_log_init(const char *subsystem, int argc, const char **argv)
146{
147 trace_probe_log.subsystem = subsystem;
148 trace_probe_log.argc = argc;
149 trace_probe_log.argv = argv;
150 trace_probe_log.index = 0;
151}
152
153void trace_probe_log_clear(void)
154{
155 memset(&trace_probe_log, 0, sizeof(trace_probe_log));
156}
157
158void trace_probe_log_set_index(int index)
159{
160 trace_probe_log.index = index;
161}
162
163void __trace_probe_log_err(int offset, int err_type)
164{
165 char *command, *p;
166 int i, len = 0, pos = 0;
167
168 if (!trace_probe_log.argv)
169 return;
170
171 /* Recalculate the length and allocate buffer */
172 for (i = 0; i < trace_probe_log.argc; i++) {
173 if (i == trace_probe_log.index)
174 pos = len;
175 len += strlen(trace_probe_log.argv[i]) + 1;
176 }
177 command = kzalloc(len, GFP_KERNEL);
178 if (!command)
179 return;
180
181 if (trace_probe_log.index >= trace_probe_log.argc) {
182 /**
183 * Set the error position is next to the last arg + space.
184 * Note that len includes the terminal null and the cursor
185 * appears at pos + 1.
186 */
187 pos = len;
188 offset = 0;
189 }
190
191 /* And make a command string from argv array */
192 p = command;
193 for (i = 0; i < trace_probe_log.argc; i++) {
194 len = strlen(trace_probe_log.argv[i]);
195 strcpy(p, trace_probe_log.argv[i]);
196 p[len] = ' ';
197 p += len + 1;
198 }
199 *(p - 1) = '\0';
200
201 tracing_log_err(NULL, trace_probe_log.subsystem, command,
202 trace_probe_err_text, err_type, pos + offset);
203
204 kfree(command);
205}
206
207/* Split symbol and offset. */
208int traceprobe_split_symbol_offset(char *symbol, long *offset)
209{
210 char *tmp;
211 int ret;
212
213 if (!offset)
214 return -EINVAL;
215
216 tmp = strpbrk(symbol, "+-");
217 if (tmp) {
218 ret = kstrtol(tmp, 0, offset);
219 if (ret)
220 return ret;
221 *tmp = '\0';
222 } else
223 *offset = 0;
224
225 return 0;
226}
227
228/* @buf must has MAX_EVENT_NAME_LEN size */
229int traceprobe_parse_event_name(const char **pevent, const char **pgroup,
230 char *buf, int offset)
231{
232 const char *slash, *event = *pevent;
233 int len;
234
235 slash = strchr(event, '/');
236 if (slash) {
237 if (slash == event) {
238 trace_probe_log_err(offset, NO_GROUP_NAME);
239 return -EINVAL;
240 }
241 if (slash - event + 1 > MAX_EVENT_NAME_LEN) {
242 trace_probe_log_err(offset, GROUP_TOO_LONG);
243 return -EINVAL;
244 }
245 strlcpy(buf, event, slash - event + 1);
246 if (!is_good_name(buf)) {
247 trace_probe_log_err(offset, BAD_GROUP_NAME);
248 return -EINVAL;
249 }
250 *pgroup = buf;
251 *pevent = slash + 1;
252 offset += slash - event + 1;
253 event = *pevent;
254 }
255 len = strlen(event);
256 if (len == 0) {
257 trace_probe_log_err(offset, NO_EVENT_NAME);
258 return -EINVAL;
259 } else if (len > MAX_EVENT_NAME_LEN) {
260 trace_probe_log_err(offset, EVENT_TOO_LONG);
261 return -EINVAL;
262 }
263 if (!is_good_name(event)) {
264 trace_probe_log_err(offset, BAD_EVENT_NAME);
265 return -EINVAL;
266 }
267 return 0;
268}
269
270#define PARAM_MAX_STACK (THREAD_SIZE / sizeof(unsigned long))
271
272static int parse_probe_vars(char *arg, const struct fetch_type *t,
273 struct fetch_insn *code, unsigned int flags, int offs)
274{
275 unsigned long param;
276 int ret = 0;
277 int len;
278
279 if (strcmp(arg, "retval") == 0) {
280 if (flags & TPARG_FL_RETURN) {
281 code->op = FETCH_OP_RETVAL;
282 } else {
283 trace_probe_log_err(offs, RETVAL_ON_PROBE);
284 ret = -EINVAL;
285 }
286 } else if ((len = str_has_prefix(arg, "stack"))) {
287 if (arg[len] == '\0') {
288 code->op = FETCH_OP_STACKP;
289 } else if (isdigit(arg[len])) {
290 ret = kstrtoul(arg + len, 10, ¶m);
291 if (ret) {
292 goto inval_var;
293 } else if ((flags & TPARG_FL_KERNEL) &&
294 param > PARAM_MAX_STACK) {
295 trace_probe_log_err(offs, BAD_STACK_NUM);
296 ret = -EINVAL;
297 } else {
298 code->op = FETCH_OP_STACK;
299 code->param = (unsigned int)param;
300 }
301 } else
302 goto inval_var;
303 } else if (strcmp(arg, "comm") == 0) {
304 code->op = FETCH_OP_COMM;
305#ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API
306 } else if (((flags & TPARG_FL_MASK) ==
307 (TPARG_FL_KERNEL | TPARG_FL_FENTRY)) &&
308 (len = str_has_prefix(arg, "arg"))) {
309 ret = kstrtoul(arg + len, 10, ¶m);
310 if (ret) {
311 goto inval_var;
312 } else if (!param || param > PARAM_MAX_STACK) {
313 trace_probe_log_err(offs, BAD_ARG_NUM);
314 return -EINVAL;
315 }
316 code->op = FETCH_OP_ARG;
317 code->param = (unsigned int)param - 1;
318#endif
319 } else
320 goto inval_var;
321
322 return ret;
323
324inval_var:
325 trace_probe_log_err(offs, BAD_VAR);
326 return -EINVAL;
327}
328
329static int str_to_immediate(char *str, unsigned long *imm)
330{
331 if (isdigit(str[0]))
332 return kstrtoul(str, 0, imm);
333 else if (str[0] == '-')
334 return kstrtol(str, 0, (long *)imm);
335 else if (str[0] == '+')
336 return kstrtol(str + 1, 0, (long *)imm);
337 return -EINVAL;
338}
339
340static int __parse_imm_string(char *str, char **pbuf, int offs)
341{
342 size_t len = strlen(str);
343
344 if (str[len - 1] != '"') {
345 trace_probe_log_err(offs + len, IMMSTR_NO_CLOSE);
346 return -EINVAL;
347 }
348 *pbuf = kstrndup(str, len - 1, GFP_KERNEL);
349 return 0;
350}
351
352/* Recursive argument parser */
353static int
354parse_probe_arg(char *arg, const struct fetch_type *type,
355 struct fetch_insn **pcode, struct fetch_insn *end,
356 unsigned int flags, int offs)
357{
358 struct fetch_insn *code = *pcode;
359 unsigned long param;
360 int deref = FETCH_OP_DEREF;
361 long offset = 0;
362 char *tmp;
363 int ret = 0;
364
365 switch (arg[0]) {
366 case '$':
367 ret = parse_probe_vars(arg + 1, type, code, flags, offs);
368 break;
369
370 case '%': /* named register */
371 ret = regs_query_register_offset(arg + 1);
372 if (ret >= 0) {
373 code->op = FETCH_OP_REG;
374 code->param = (unsigned int)ret;
375 ret = 0;
376 } else
377 trace_probe_log_err(offs, BAD_REG_NAME);
378 break;
379
380 case '@': /* memory, file-offset or symbol */
381 if (isdigit(arg[1])) {
382 ret = kstrtoul(arg + 1, 0, ¶m);
383 if (ret) {
384 trace_probe_log_err(offs, BAD_MEM_ADDR);
385 break;
386 }
387 /* load address */
388 code->op = FETCH_OP_IMM;
389 code->immediate = param;
390 } else if (arg[1] == '+') {
391 /* kprobes don't support file offsets */
392 if (flags & TPARG_FL_KERNEL) {
393 trace_probe_log_err(offs, FILE_ON_KPROBE);
394 return -EINVAL;
395 }
396 ret = kstrtol(arg + 2, 0, &offset);
397 if (ret) {
398 trace_probe_log_err(offs, BAD_FILE_OFFS);
399 break;
400 }
401
402 code->op = FETCH_OP_FOFFS;
403 code->immediate = (unsigned long)offset; // imm64?
404 } else {
405 /* uprobes don't support symbols */
406 if (!(flags & TPARG_FL_KERNEL)) {
407 trace_probe_log_err(offs, SYM_ON_UPROBE);
408 return -EINVAL;
409 }
410 /* Preserve symbol for updating */
411 code->op = FETCH_NOP_SYMBOL;
412 code->data = kstrdup(arg + 1, GFP_KERNEL);
413 if (!code->data)
414 return -ENOMEM;
415 if (++code == end) {
416 trace_probe_log_err(offs, TOO_MANY_OPS);
417 return -EINVAL;
418 }
419 code->op = FETCH_OP_IMM;
420 code->immediate = 0;
421 }
422 /* These are fetching from memory */
423 if (++code == end) {
424 trace_probe_log_err(offs, TOO_MANY_OPS);
425 return -EINVAL;
426 }
427 *pcode = code;
428 code->op = FETCH_OP_DEREF;
429 code->offset = offset;
430 break;
431
432 case '+': /* deref memory */
433 case '-':
434 if (arg[1] == 'u') {
435 deref = FETCH_OP_UDEREF;
436 arg[1] = arg[0];
437 arg++;
438 }
439 if (arg[0] == '+')
440 arg++; /* Skip '+', because kstrtol() rejects it. */
441 tmp = strchr(arg, '(');
442 if (!tmp) {
443 trace_probe_log_err(offs, DEREF_NEED_BRACE);
444 return -EINVAL;
445 }
446 *tmp = '\0';
447 ret = kstrtol(arg, 0, &offset);
448 if (ret) {
449 trace_probe_log_err(offs, BAD_DEREF_OFFS);
450 break;
451 }
452 offs += (tmp + 1 - arg) + (arg[0] != '-' ? 1 : 0);
453 arg = tmp + 1;
454 tmp = strrchr(arg, ')');
455 if (!tmp) {
456 trace_probe_log_err(offs + strlen(arg),
457 DEREF_OPEN_BRACE);
458 return -EINVAL;
459 } else {
460 const struct fetch_type *t2 = find_fetch_type(NULL);
461
462 *tmp = '\0';
463 ret = parse_probe_arg(arg, t2, &code, end, flags, offs);
464 if (ret)
465 break;
466 if (code->op == FETCH_OP_COMM ||
467 code->op == FETCH_OP_DATA) {
468 trace_probe_log_err(offs, COMM_CANT_DEREF);
469 return -EINVAL;
470 }
471 if (++code == end) {
472 trace_probe_log_err(offs, TOO_MANY_OPS);
473 return -EINVAL;
474 }
475 *pcode = code;
476
477 code->op = deref;
478 code->offset = offset;
479 }
480 break;
481 case '\\': /* Immediate value */
482 if (arg[1] == '"') { /* Immediate string */
483 ret = __parse_imm_string(arg + 2, &tmp, offs + 2);
484 if (ret)
485 break;
486 code->op = FETCH_OP_DATA;
487 code->data = tmp;
488 } else {
489 ret = str_to_immediate(arg + 1, &code->immediate);
490 if (ret)
491 trace_probe_log_err(offs + 1, BAD_IMM);
492 else
493 code->op = FETCH_OP_IMM;
494 }
495 break;
496 }
497 if (!ret && code->op == FETCH_OP_NOP) {
498 /* Parsed, but do not find fetch method */
499 trace_probe_log_err(offs, BAD_FETCH_ARG);
500 ret = -EINVAL;
501 }
502 return ret;
503}
504
505#define BYTES_TO_BITS(nb) ((BITS_PER_LONG * (nb)) / sizeof(long))
506
507/* Bitfield type needs to be parsed into a fetch function */
508static int __parse_bitfield_probe_arg(const char *bf,
509 const struct fetch_type *t,
510 struct fetch_insn **pcode)
511{
512 struct fetch_insn *code = *pcode;
513 unsigned long bw, bo;
514 char *tail;
515
516 if (*bf != 'b')
517 return 0;
518
519 bw = simple_strtoul(bf + 1, &tail, 0); /* Use simple one */
520
521 if (bw == 0 || *tail != '@')
522 return -EINVAL;
523
524 bf = tail + 1;
525 bo = simple_strtoul(bf, &tail, 0);
526
527 if (tail == bf || *tail != '/')
528 return -EINVAL;
529 code++;
530 if (code->op != FETCH_OP_NOP)
531 return -EINVAL;
532 *pcode = code;
533
534 code->op = FETCH_OP_MOD_BF;
535 code->lshift = BYTES_TO_BITS(t->size) - (bw + bo);
536 code->rshift = BYTES_TO_BITS(t->size) - bw;
537 code->basesize = t->size;
538
539 return (BYTES_TO_BITS(t->size) < (bw + bo)) ? -EINVAL : 0;
540}
541
542/* String length checking wrapper */
543static int traceprobe_parse_probe_arg_body(char *arg, ssize_t *size,
544 struct probe_arg *parg, unsigned int flags, int offset)
545{
546 struct fetch_insn *code, *scode, *tmp = NULL;
547 char *t, *t2, *t3;
548 int ret, len;
549
550 len = strlen(arg);
551 if (len > MAX_ARGSTR_LEN) {
552 trace_probe_log_err(offset, ARG_TOO_LONG);
553 return -EINVAL;
554 } else if (len == 0) {
555 trace_probe_log_err(offset, NO_ARG_BODY);
556 return -EINVAL;
557 }
558
559 parg->comm = kstrdup(arg, GFP_KERNEL);
560 if (!parg->comm)
561 return -ENOMEM;
562
563 t = strchr(arg, ':');
564 if (t) {
565 *t = '\0';
566 t2 = strchr(++t, '[');
567 if (t2) {
568 *t2++ = '\0';
569 t3 = strchr(t2, ']');
570 if (!t3) {
571 offset += t2 + strlen(t2) - arg;
572 trace_probe_log_err(offset,
573 ARRAY_NO_CLOSE);
574 return -EINVAL;
575 } else if (t3[1] != '\0') {
576 trace_probe_log_err(offset + t3 + 1 - arg,
577 BAD_ARRAY_SUFFIX);
578 return -EINVAL;
579 }
580 *t3 = '\0';
581 if (kstrtouint(t2, 0, &parg->count) || !parg->count) {
582 trace_probe_log_err(offset + t2 - arg,
583 BAD_ARRAY_NUM);
584 return -EINVAL;
585 }
586 if (parg->count > MAX_ARRAY_LEN) {
587 trace_probe_log_err(offset + t2 - arg,
588 ARRAY_TOO_BIG);
589 return -EINVAL;
590 }
591 }
592 }
593
594 /*
595 * Since $comm and immediate string can not be dereferenced,
596 * we can find those by strcmp.
597 */
598 if (strcmp(arg, "$comm") == 0 || strncmp(arg, "\\\"", 2) == 0) {
599 /* The type of $comm must be "string", and not an array. */
600 if (parg->count || (t && strcmp(t, "string")))
601 return -EINVAL;
602 parg->type = find_fetch_type("string");
603 } else
604 parg->type = find_fetch_type(t);
605 if (!parg->type) {
606 trace_probe_log_err(offset + (t ? (t - arg) : 0), BAD_TYPE);
607 return -EINVAL;
608 }
609 parg->offset = *size;
610 *size += parg->type->size * (parg->count ?: 1);
611
612 if (parg->count) {
613 len = strlen(parg->type->fmttype) + 6;
614 parg->fmt = kmalloc(len, GFP_KERNEL);
615 if (!parg->fmt)
616 return -ENOMEM;
617 snprintf(parg->fmt, len, "%s[%d]", parg->type->fmttype,
618 parg->count);
619 }
620
621 code = tmp = kcalloc(FETCH_INSN_MAX, sizeof(*code), GFP_KERNEL);
622 if (!code)
623 return -ENOMEM;
624 code[FETCH_INSN_MAX - 1].op = FETCH_OP_END;
625
626 ret = parse_probe_arg(arg, parg->type, &code, &code[FETCH_INSN_MAX - 1],
627 flags, offset);
628 if (ret)
629 goto fail;
630
631 /* Store operation */
632 if (!strcmp(parg->type->name, "string") ||
633 !strcmp(parg->type->name, "ustring")) {
634 if (code->op != FETCH_OP_DEREF && code->op != FETCH_OP_UDEREF &&
635 code->op != FETCH_OP_IMM && code->op != FETCH_OP_COMM &&
636 code->op != FETCH_OP_DATA) {
637 trace_probe_log_err(offset + (t ? (t - arg) : 0),
638 BAD_STRING);
639 ret = -EINVAL;
640 goto fail;
641 }
642 if ((code->op == FETCH_OP_IMM || code->op == FETCH_OP_COMM ||
643 code->op == FETCH_OP_DATA) || parg->count) {
644 /*
645 * IMM, DATA and COMM is pointing actual address, those
646 * must be kept, and if parg->count != 0, this is an
647 * array of string pointers instead of string address
648 * itself.
649 */
650 code++;
651 if (code->op != FETCH_OP_NOP) {
652 trace_probe_log_err(offset, TOO_MANY_OPS);
653 ret = -EINVAL;
654 goto fail;
655 }
656 }
657 /* If op == DEREF, replace it with STRING */
658 if (!strcmp(parg->type->name, "ustring") ||
659 code->op == FETCH_OP_UDEREF)
660 code->op = FETCH_OP_ST_USTRING;
661 else
662 code->op = FETCH_OP_ST_STRING;
663 code->size = parg->type->size;
664 parg->dynamic = true;
665 } else if (code->op == FETCH_OP_DEREF) {
666 code->op = FETCH_OP_ST_MEM;
667 code->size = parg->type->size;
668 } else if (code->op == FETCH_OP_UDEREF) {
669 code->op = FETCH_OP_ST_UMEM;
670 code->size = parg->type->size;
671 } else {
672 code++;
673 if (code->op != FETCH_OP_NOP) {
674 trace_probe_log_err(offset, TOO_MANY_OPS);
675 ret = -EINVAL;
676 goto fail;
677 }
678 code->op = FETCH_OP_ST_RAW;
679 code->size = parg->type->size;
680 }
681 scode = code;
682 /* Modify operation */
683 if (t != NULL) {
684 ret = __parse_bitfield_probe_arg(t, parg->type, &code);
685 if (ret) {
686 trace_probe_log_err(offset + t - arg, BAD_BITFIELD);
687 goto fail;
688 }
689 }
690 /* Loop(Array) operation */
691 if (parg->count) {
692 if (scode->op != FETCH_OP_ST_MEM &&
693 scode->op != FETCH_OP_ST_STRING &&
694 scode->op != FETCH_OP_ST_USTRING) {
695 trace_probe_log_err(offset + (t ? (t - arg) : 0),
696 BAD_STRING);
697 ret = -EINVAL;
698 goto fail;
699 }
700 code++;
701 if (code->op != FETCH_OP_NOP) {
702 trace_probe_log_err(offset, TOO_MANY_OPS);
703 ret = -EINVAL;
704 goto fail;
705 }
706 code->op = FETCH_OP_LP_ARRAY;
707 code->param = parg->count;
708 }
709 code++;
710 code->op = FETCH_OP_END;
711
712 /* Shrink down the code buffer */
713 parg->code = kcalloc(code - tmp + 1, sizeof(*code), GFP_KERNEL);
714 if (!parg->code)
715 ret = -ENOMEM;
716 else
717 memcpy(parg->code, tmp, sizeof(*code) * (code - tmp + 1));
718
719fail:
720 if (ret) {
721 for (code = tmp; code < tmp + FETCH_INSN_MAX; code++)
722 if (code->op == FETCH_NOP_SYMBOL ||
723 code->op == FETCH_OP_DATA)
724 kfree(code->data);
725 }
726 kfree(tmp);
727
728 return ret;
729}
730
731/* Return 1 if name is reserved or already used by another argument */
732static int traceprobe_conflict_field_name(const char *name,
733 struct probe_arg *args, int narg)
734{
735 int i;
736
737 for (i = 0; i < ARRAY_SIZE(reserved_field_names); i++)
738 if (strcmp(reserved_field_names[i], name) == 0)
739 return 1;
740
741 for (i = 0; i < narg; i++)
742 if (strcmp(args[i].name, name) == 0)
743 return 1;
744
745 return 0;
746}
747
748int traceprobe_parse_probe_arg(struct trace_probe *tp, int i, char *arg,
749 unsigned int flags)
750{
751 struct probe_arg *parg = &tp->args[i];
752 char *body;
753
754 /* Increment count for freeing args in error case */
755 tp->nr_args++;
756
757 body = strchr(arg, '=');
758 if (body) {
759 if (body - arg > MAX_ARG_NAME_LEN) {
760 trace_probe_log_err(0, ARG_NAME_TOO_LONG);
761 return -EINVAL;
762 } else if (body == arg) {
763 trace_probe_log_err(0, NO_ARG_NAME);
764 return -EINVAL;
765 }
766 parg->name = kmemdup_nul(arg, body - arg, GFP_KERNEL);
767 body++;
768 } else {
769 /* If argument name is omitted, set "argN" */
770 parg->name = kasprintf(GFP_KERNEL, "arg%d", i + 1);
771 body = arg;
772 }
773 if (!parg->name)
774 return -ENOMEM;
775
776 if (!is_good_name(parg->name)) {
777 trace_probe_log_err(0, BAD_ARG_NAME);
778 return -EINVAL;
779 }
780 if (traceprobe_conflict_field_name(parg->name, tp->args, i)) {
781 trace_probe_log_err(0, USED_ARG_NAME);
782 return -EINVAL;
783 }
784 /* Parse fetch argument */
785 return traceprobe_parse_probe_arg_body(body, &tp->size, parg, flags,
786 body - arg);
787}
788
789void traceprobe_free_probe_arg(struct probe_arg *arg)
790{
791 struct fetch_insn *code = arg->code;
792
793 while (code && code->op != FETCH_OP_END) {
794 if (code->op == FETCH_NOP_SYMBOL ||
795 code->op == FETCH_OP_DATA)
796 kfree(code->data);
797 code++;
798 }
799 kfree(arg->code);
800 kfree(arg->name);
801 kfree(arg->comm);
802 kfree(arg->fmt);
803}
804
805int traceprobe_update_arg(struct probe_arg *arg)
806{
807 struct fetch_insn *code = arg->code;
808 long offset;
809 char *tmp;
810 char c;
811 int ret = 0;
812
813 while (code && code->op != FETCH_OP_END) {
814 if (code->op == FETCH_NOP_SYMBOL) {
815 if (code[1].op != FETCH_OP_IMM)
816 return -EINVAL;
817
818 tmp = strpbrk(code->data, "+-");
819 if (tmp)
820 c = *tmp;
821 ret = traceprobe_split_symbol_offset(code->data,
822 &offset);
823 if (ret)
824 return ret;
825
826 code[1].immediate =
827 (unsigned long)kallsyms_lookup_name(code->data);
828 if (tmp)
829 *tmp = c;
830 if (!code[1].immediate)
831 return -ENOENT;
832 code[1].immediate += offset;
833 }
834 code++;
835 }
836 return 0;
837}
838
839/* When len=0, we just calculate the needed length */
840#define LEN_OR_ZERO (len ? len - pos : 0)
841static int __set_print_fmt(struct trace_probe *tp, char *buf, int len,
842 bool is_return)
843{
844 struct probe_arg *parg;
845 int i, j;
846 int pos = 0;
847 const char *fmt, *arg;
848
849 if (!is_return) {
850 fmt = "(%lx)";
851 arg = "REC->" FIELD_STRING_IP;
852 } else {
853 fmt = "(%lx <- %lx)";
854 arg = "REC->" FIELD_STRING_FUNC ", REC->" FIELD_STRING_RETIP;
855 }
856
857 pos += snprintf(buf + pos, LEN_OR_ZERO, "\"%s", fmt);
858
859 for (i = 0; i < tp->nr_args; i++) {
860 parg = tp->args + i;
861 pos += snprintf(buf + pos, LEN_OR_ZERO, " %s=", parg->name);
862 if (parg->count) {
863 pos += snprintf(buf + pos, LEN_OR_ZERO, "{%s",
864 parg->type->fmt);
865 for (j = 1; j < parg->count; j++)
866 pos += snprintf(buf + pos, LEN_OR_ZERO, ",%s",
867 parg->type->fmt);
868 pos += snprintf(buf + pos, LEN_OR_ZERO, "}");
869 } else
870 pos += snprintf(buf + pos, LEN_OR_ZERO, "%s",
871 parg->type->fmt);
872 }
873
874 pos += snprintf(buf + pos, LEN_OR_ZERO, "\", %s", arg);
875
876 for (i = 0; i < tp->nr_args; i++) {
877 parg = tp->args + i;
878 if (parg->count) {
879 if ((strcmp(parg->type->name, "string") == 0) ||
880 (strcmp(parg->type->name, "ustring") == 0))
881 fmt = ", __get_str(%s[%d])";
882 else
883 fmt = ", REC->%s[%d]";
884 for (j = 0; j < parg->count; j++)
885 pos += snprintf(buf + pos, LEN_OR_ZERO,
886 fmt, parg->name, j);
887 } else {
888 if ((strcmp(parg->type->name, "string") == 0) ||
889 (strcmp(parg->type->name, "ustring") == 0))
890 fmt = ", __get_str(%s)";
891 else
892 fmt = ", REC->%s";
893 pos += snprintf(buf + pos, LEN_OR_ZERO,
894 fmt, parg->name);
895 }
896 }
897
898 /* return the length of print_fmt */
899 return pos;
900}
901#undef LEN_OR_ZERO
902
903int traceprobe_set_print_fmt(struct trace_probe *tp, bool is_return)
904{
905 struct trace_event_call *call = trace_probe_event_call(tp);
906 int len;
907 char *print_fmt;
908
909 /* First: called with 0 length to calculate the needed length */
910 len = __set_print_fmt(tp, NULL, 0, is_return);
911 print_fmt = kmalloc(len + 1, GFP_KERNEL);
912 if (!print_fmt)
913 return -ENOMEM;
914
915 /* Second: actually write the @print_fmt */
916 __set_print_fmt(tp, print_fmt, len + 1, is_return);
917 call->print_fmt = print_fmt;
918
919 return 0;
920}
921
922int traceprobe_define_arg_fields(struct trace_event_call *event_call,
923 size_t offset, struct trace_probe *tp)
924{
925 int ret, i;
926
927 /* Set argument names as fields */
928 for (i = 0; i < tp->nr_args; i++) {
929 struct probe_arg *parg = &tp->args[i];
930 const char *fmt = parg->type->fmttype;
931 int size = parg->type->size;
932
933 if (parg->fmt)
934 fmt = parg->fmt;
935 if (parg->count)
936 size *= parg->count;
937 ret = trace_define_field(event_call, fmt, parg->name,
938 offset + parg->offset, size,
939 parg->type->is_signed,
940 FILTER_OTHER);
941 if (ret)
942 return ret;
943 }
944 return 0;
945}
946
947static void trace_probe_event_free(struct trace_probe_event *tpe)
948{
949 kfree(tpe->class.system);
950 kfree(tpe->call.name);
951 kfree(tpe->call.print_fmt);
952 kfree(tpe);
953}
954
955int trace_probe_append(struct trace_probe *tp, struct trace_probe *to)
956{
957 if (trace_probe_has_sibling(tp))
958 return -EBUSY;
959
960 list_del_init(&tp->list);
961 trace_probe_event_free(tp->event);
962
963 tp->event = to->event;
964 list_add_tail(&tp->list, trace_probe_probe_list(to));
965
966 return 0;
967}
968
969void trace_probe_unlink(struct trace_probe *tp)
970{
971 list_del_init(&tp->list);
972 if (list_empty(trace_probe_probe_list(tp)))
973 trace_probe_event_free(tp->event);
974 tp->event = NULL;
975}
976
977void trace_probe_cleanup(struct trace_probe *tp)
978{
979 int i;
980
981 for (i = 0; i < tp->nr_args; i++)
982 traceprobe_free_probe_arg(&tp->args[i]);
983
984 if (tp->event)
985 trace_probe_unlink(tp);
986}
987
988int trace_probe_init(struct trace_probe *tp, const char *event,
989 const char *group, bool alloc_filter)
990{
991 struct trace_event_call *call;
992 size_t size = sizeof(struct trace_probe_event);
993 int ret = 0;
994
995 if (!event || !group)
996 return -EINVAL;
997
998 if (alloc_filter)
999 size += sizeof(struct trace_uprobe_filter);
1000
1001 tp->event = kzalloc(size, GFP_KERNEL);
1002 if (!tp->event)
1003 return -ENOMEM;
1004
1005 INIT_LIST_HEAD(&tp->event->files);
1006 INIT_LIST_HEAD(&tp->event->class.fields);
1007 INIT_LIST_HEAD(&tp->event->probes);
1008 INIT_LIST_HEAD(&tp->list);
1009 list_add(&tp->list, &tp->event->probes);
1010
1011 call = trace_probe_event_call(tp);
1012 call->class = &tp->event->class;
1013 call->name = kstrdup(event, GFP_KERNEL);
1014 if (!call->name) {
1015 ret = -ENOMEM;
1016 goto error;
1017 }
1018
1019 tp->event->class.system = kstrdup(group, GFP_KERNEL);
1020 if (!tp->event->class.system) {
1021 ret = -ENOMEM;
1022 goto error;
1023 }
1024
1025 return 0;
1026
1027error:
1028 trace_probe_cleanup(tp);
1029 return ret;
1030}
1031
1032static struct trace_event_call *
1033find_trace_event_call(const char *system, const char *event_name)
1034{
1035 struct trace_event_call *tp_event;
1036 const char *name;
1037
1038 list_for_each_entry(tp_event, &ftrace_events, list) {
1039 if (!tp_event->class->system ||
1040 strcmp(system, tp_event->class->system))
1041 continue;
1042 name = trace_event_name(tp_event);
1043 if (!name || strcmp(event_name, name))
1044 continue;
1045 return tp_event;
1046 }
1047
1048 return NULL;
1049}
1050
1051int trace_probe_register_event_call(struct trace_probe *tp)
1052{
1053 struct trace_event_call *call = trace_probe_event_call(tp);
1054 int ret;
1055
1056 lockdep_assert_held(&event_mutex);
1057
1058 if (find_trace_event_call(trace_probe_group_name(tp),
1059 trace_probe_name(tp)))
1060 return -EEXIST;
1061
1062 ret = register_trace_event(&call->event);
1063 if (!ret)
1064 return -ENODEV;
1065
1066 ret = trace_add_event_call(call);
1067 if (ret)
1068 unregister_trace_event(&call->event);
1069
1070 return ret;
1071}
1072
1073int trace_probe_add_file(struct trace_probe *tp, struct trace_event_file *file)
1074{
1075 struct event_file_link *link;
1076
1077 link = kmalloc(sizeof(*link), GFP_KERNEL);
1078 if (!link)
1079 return -ENOMEM;
1080
1081 link->file = file;
1082 INIT_LIST_HEAD(&link->list);
1083 list_add_tail_rcu(&link->list, &tp->event->files);
1084 trace_probe_set_flag(tp, TP_FLAG_TRACE);
1085 return 0;
1086}
1087
1088struct event_file_link *trace_probe_get_file_link(struct trace_probe *tp,
1089 struct trace_event_file *file)
1090{
1091 struct event_file_link *link;
1092
1093 trace_probe_for_each_link(link, tp) {
1094 if (link->file == file)
1095 return link;
1096 }
1097
1098 return NULL;
1099}
1100
1101int trace_probe_remove_file(struct trace_probe *tp,
1102 struct trace_event_file *file)
1103{
1104 struct event_file_link *link;
1105
1106 link = trace_probe_get_file_link(tp, file);
1107 if (!link)
1108 return -ENOENT;
1109
1110 list_del_rcu(&link->list);
1111 synchronize_rcu();
1112 kfree(link);
1113
1114 if (list_empty(&tp->event->files))
1115 trace_probe_clear_flag(tp, TP_FLAG_TRACE);
1116
1117 return 0;
1118}
1119
1120/*
1121 * Return the smallest index of different type argument (start from 1).
1122 * If all argument types and name are same, return 0.
1123 */
1124int trace_probe_compare_arg_type(struct trace_probe *a, struct trace_probe *b)
1125{
1126 int i;
1127
1128 /* In case of more arguments */
1129 if (a->nr_args < b->nr_args)
1130 return a->nr_args + 1;
1131 if (a->nr_args > b->nr_args)
1132 return b->nr_args + 1;
1133
1134 for (i = 0; i < a->nr_args; i++) {
1135 if ((b->nr_args <= i) ||
1136 ((a->args[i].type != b->args[i].type) ||
1137 (a->args[i].count != b->args[i].count) ||
1138 strcmp(a->args[i].name, b->args[i].name)))
1139 return i + 1;
1140 }
1141
1142 return 0;
1143}
1144
1145bool trace_probe_match_command_args(struct trace_probe *tp,
1146 int argc, const char **argv)
1147{
1148 char buf[MAX_ARGSTR_LEN + 1];
1149 int i;
1150
1151 if (tp->nr_args < argc)
1152 return false;
1153
1154 for (i = 0; i < argc; i++) {
1155 snprintf(buf, sizeof(buf), "%s=%s",
1156 tp->args[i].name, tp->args[i].comm);
1157 if (strcmp(buf, argv[i]))
1158 return false;
1159 }
1160 return true;
1161}
1162
1163int trace_probe_create(const char *raw_command, int (*createfn)(int, const char **))
1164{
1165 int argc = 0, ret = 0;
1166 char **argv;
1167
1168 argv = argv_split(GFP_KERNEL, raw_command, &argc);
1169 if (!argv)
1170 return -ENOMEM;
1171
1172 if (argc)
1173 ret = createfn(argc, (const char **)argv);
1174
1175 argv_free(argv);
1176
1177 return ret;
1178}