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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/*
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}