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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,
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 /* Recalcurate 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 * appaers 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 $comm and immediate string can not be dereferred,
596 * we can find those by strcmp.
597 */
598 if (strcmp(arg, "$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 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 fmt = ", __get_str(%s[%d])";
881 else
882 fmt = ", REC->%s[%d]";
883 for (j = 0; j < parg->count; j++)
884 pos += snprintf(buf + pos, LEN_OR_ZERO,
885 fmt, parg->name, j);
886 } else {
887 if (strcmp(parg->type->name, "string") == 0)
888 fmt = ", __get_str(%s)";
889 else
890 fmt = ", REC->%s";
891 pos += snprintf(buf + pos, LEN_OR_ZERO,
892 fmt, parg->name);
893 }
894 }
895
896 /* return the length of print_fmt */
897 return pos;
898}
899#undef LEN_OR_ZERO
900
901int traceprobe_set_print_fmt(struct trace_probe *tp, bool is_return)
902{
903 struct trace_event_call *call = trace_probe_event_call(tp);
904 int len;
905 char *print_fmt;
906
907 /* First: called with 0 length to calculate the needed length */
908 len = __set_print_fmt(tp, NULL, 0, is_return);
909 print_fmt = kmalloc(len + 1, GFP_KERNEL);
910 if (!print_fmt)
911 return -ENOMEM;
912
913 /* Second: actually write the @print_fmt */
914 __set_print_fmt(tp, print_fmt, len + 1, is_return);
915 call->print_fmt = print_fmt;
916
917 return 0;
918}
919
920int traceprobe_define_arg_fields(struct trace_event_call *event_call,
921 size_t offset, struct trace_probe *tp)
922{
923 int ret, i;
924
925 /* Set argument names as fields */
926 for (i = 0; i < tp->nr_args; i++) {
927 struct probe_arg *parg = &tp->args[i];
928 const char *fmt = parg->type->fmttype;
929 int size = parg->type->size;
930
931 if (parg->fmt)
932 fmt = parg->fmt;
933 if (parg->count)
934 size *= parg->count;
935 ret = trace_define_field(event_call, fmt, parg->name,
936 offset + parg->offset, size,
937 parg->type->is_signed,
938 FILTER_OTHER);
939 if (ret)
940 return ret;
941 }
942 return 0;
943}
944
945static void trace_probe_event_free(struct trace_probe_event *tpe)
946{
947 kfree(tpe->class.system);
948 kfree(tpe->call.name);
949 kfree(tpe->call.print_fmt);
950 kfree(tpe);
951}
952
953int trace_probe_append(struct trace_probe *tp, struct trace_probe *to)
954{
955 if (trace_probe_has_sibling(tp))
956 return -EBUSY;
957
958 list_del_init(&tp->list);
959 trace_probe_event_free(tp->event);
960
961 tp->event = to->event;
962 list_add_tail(&tp->list, trace_probe_probe_list(to));
963
964 return 0;
965}
966
967void trace_probe_unlink(struct trace_probe *tp)
968{
969 list_del_init(&tp->list);
970 if (list_empty(trace_probe_probe_list(tp)))
971 trace_probe_event_free(tp->event);
972 tp->event = NULL;
973}
974
975void trace_probe_cleanup(struct trace_probe *tp)
976{
977 int i;
978
979 for (i = 0; i < tp->nr_args; i++)
980 traceprobe_free_probe_arg(&tp->args[i]);
981
982 if (tp->event)
983 trace_probe_unlink(tp);
984}
985
986int trace_probe_init(struct trace_probe *tp, const char *event,
987 const char *group)
988{
989 struct trace_event_call *call;
990 int ret = 0;
991
992 if (!event || !group)
993 return -EINVAL;
994
995 tp->event = kzalloc(sizeof(struct trace_probe_event), GFP_KERNEL);
996 if (!tp->event)
997 return -ENOMEM;
998
999 INIT_LIST_HEAD(&tp->event->files);
1000 INIT_LIST_HEAD(&tp->event->class.fields);
1001 INIT_LIST_HEAD(&tp->event->probes);
1002 INIT_LIST_HEAD(&tp->list);
1003 list_add(&tp->event->probes, &tp->list);
1004
1005 call = trace_probe_event_call(tp);
1006 call->class = &tp->event->class;
1007 call->name = kstrdup(event, GFP_KERNEL);
1008 if (!call->name) {
1009 ret = -ENOMEM;
1010 goto error;
1011 }
1012
1013 tp->event->class.system = kstrdup(group, GFP_KERNEL);
1014 if (!tp->event->class.system) {
1015 ret = -ENOMEM;
1016 goto error;
1017 }
1018
1019 return 0;
1020
1021error:
1022 trace_probe_cleanup(tp);
1023 return ret;
1024}
1025
1026int trace_probe_register_event_call(struct trace_probe *tp)
1027{
1028 struct trace_event_call *call = trace_probe_event_call(tp);
1029 int ret;
1030
1031 ret = register_trace_event(&call->event);
1032 if (!ret)
1033 return -ENODEV;
1034
1035 ret = trace_add_event_call(call);
1036 if (ret)
1037 unregister_trace_event(&call->event);
1038
1039 return ret;
1040}
1041
1042int trace_probe_add_file(struct trace_probe *tp, struct trace_event_file *file)
1043{
1044 struct event_file_link *link;
1045
1046 link = kmalloc(sizeof(*link), GFP_KERNEL);
1047 if (!link)
1048 return -ENOMEM;
1049
1050 link->file = file;
1051 INIT_LIST_HEAD(&link->list);
1052 list_add_tail_rcu(&link->list, &tp->event->files);
1053 trace_probe_set_flag(tp, TP_FLAG_TRACE);
1054 return 0;
1055}
1056
1057struct event_file_link *trace_probe_get_file_link(struct trace_probe *tp,
1058 struct trace_event_file *file)
1059{
1060 struct event_file_link *link;
1061
1062 trace_probe_for_each_link(link, tp) {
1063 if (link->file == file)
1064 return link;
1065 }
1066
1067 return NULL;
1068}
1069
1070int trace_probe_remove_file(struct trace_probe *tp,
1071 struct trace_event_file *file)
1072{
1073 struct event_file_link *link;
1074
1075 link = trace_probe_get_file_link(tp, file);
1076 if (!link)
1077 return -ENOENT;
1078
1079 list_del_rcu(&link->list);
1080 synchronize_rcu();
1081 kfree(link);
1082
1083 if (list_empty(&tp->event->files))
1084 trace_probe_clear_flag(tp, TP_FLAG_TRACE);
1085
1086 return 0;
1087}
1088
1089/*
1090 * Return the smallest index of different type argument (start from 1).
1091 * If all argument types and name are same, return 0.
1092 */
1093int trace_probe_compare_arg_type(struct trace_probe *a, struct trace_probe *b)
1094{
1095 int i;
1096
1097 /* In case of more arguments */
1098 if (a->nr_args < b->nr_args)
1099 return a->nr_args + 1;
1100 if (a->nr_args > b->nr_args)
1101 return b->nr_args + 1;
1102
1103 for (i = 0; i < a->nr_args; i++) {
1104 if ((b->nr_args <= i) ||
1105 ((a->args[i].type != b->args[i].type) ||
1106 (a->args[i].count != b->args[i].count) ||
1107 strcmp(a->args[i].name, b->args[i].name)))
1108 return i + 1;
1109 }
1110
1111 return 0;
1112}
1113
1114bool trace_probe_match_command_args(struct trace_probe *tp,
1115 int argc, const char **argv)
1116{
1117 char buf[MAX_ARGSTR_LEN + 1];
1118 int i;
1119
1120 if (tp->nr_args < argc)
1121 return false;
1122
1123 for (i = 0; i < argc; i++) {
1124 snprintf(buf, sizeof(buf), "%s=%s",
1125 tp->args[i].name, tp->args[i].comm);
1126 if (strcmp(buf, argv[i]))
1127 return false;
1128 }
1129 return true;
1130}
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) \
40__kprobes int PRINT_TYPE_FUNC_NAME(type)(struct trace_seq *s, \
41 const char *name, \
42 void *data, void *ent) \
43{ \
44 return trace_seq_printf(s, " %s=" fmt, name, *(type *)data); \
45} \
46const char PRINT_TYPE_FMT_NAME(type)[] = fmt;
47
48DEFINE_BASIC_PRINT_TYPE_FUNC(u8 , "0x%x")
49DEFINE_BASIC_PRINT_TYPE_FUNC(u16, "0x%x")
50DEFINE_BASIC_PRINT_TYPE_FUNC(u32, "0x%x")
51DEFINE_BASIC_PRINT_TYPE_FUNC(u64, "0x%Lx")
52DEFINE_BASIC_PRINT_TYPE_FUNC(s8, "%d")
53DEFINE_BASIC_PRINT_TYPE_FUNC(s16, "%d")
54DEFINE_BASIC_PRINT_TYPE_FUNC(s32, "%d")
55DEFINE_BASIC_PRINT_TYPE_FUNC(s64, "%Ld")
56
57/* Print type function for string type */
58__kprobes int PRINT_TYPE_FUNC_NAME(string)(struct trace_seq *s,
59 const char *name,
60 void *data, void *ent)
61{
62 int len = *(u32 *)data >> 16;
63
64 if (!len)
65 return trace_seq_printf(s, " %s=(fault)", name);
66 else
67 return trace_seq_printf(s, " %s=\"%s\"", name,
68 (const char *)get_loc_data(data, ent));
69}
70
71const char PRINT_TYPE_FMT_NAME(string)[] = "\\\"%s\\\"";
72
73#define CHECK_FETCH_FUNCS(method, fn) \
74 (((FETCH_FUNC_NAME(method, u8) == fn) || \
75 (FETCH_FUNC_NAME(method, u16) == fn) || \
76 (FETCH_FUNC_NAME(method, u32) == fn) || \
77 (FETCH_FUNC_NAME(method, u64) == fn) || \
78 (FETCH_FUNC_NAME(method, string) == fn) || \
79 (FETCH_FUNC_NAME(method, string_size) == fn)) \
80 && (fn != NULL))
81
82/* Data fetch function templates */
83#define DEFINE_FETCH_reg(type) \
84__kprobes void FETCH_FUNC_NAME(reg, type)(struct pt_regs *regs, \
85 void *offset, void *dest) \
86{ \
87 *(type *)dest = (type)regs_get_register(regs, \
88 (unsigned int)((unsigned long)offset)); \
89}
90DEFINE_BASIC_FETCH_FUNCS(reg)
91/* No string on the register */
92#define fetch_reg_string NULL
93#define fetch_reg_string_size NULL
94
95#define DEFINE_FETCH_retval(type) \
96__kprobes void FETCH_FUNC_NAME(retval, type)(struct pt_regs *regs, \
97 void *dummy, void *dest) \
98{ \
99 *(type *)dest = (type)regs_return_value(regs); \
100}
101DEFINE_BASIC_FETCH_FUNCS(retval)
102/* No string on the retval */
103#define fetch_retval_string NULL
104#define fetch_retval_string_size NULL
105
106/* Dereference memory access function */
107struct deref_fetch_param {
108 struct fetch_param orig;
109 long offset;
110 fetch_func_t fetch;
111 fetch_func_t fetch_size;
112};
113
114#define DEFINE_FETCH_deref(type) \
115__kprobes void FETCH_FUNC_NAME(deref, type)(struct pt_regs *regs, \
116 void *data, void *dest) \
117{ \
118 struct deref_fetch_param *dprm = data; \
119 unsigned long addr; \
120 call_fetch(&dprm->orig, regs, &addr); \
121 if (addr) { \
122 addr += dprm->offset; \
123 dprm->fetch(regs, (void *)addr, dest); \
124 } else \
125 *(type *)dest = 0; \
126}
127DEFINE_BASIC_FETCH_FUNCS(deref)
128DEFINE_FETCH_deref(string)
129
130__kprobes void FETCH_FUNC_NAME(deref, string_size)(struct pt_regs *regs,
131 void *data, void *dest)
132{
133 struct deref_fetch_param *dprm = data;
134 unsigned long addr;
135
136 call_fetch(&dprm->orig, regs, &addr);
137 if (addr && dprm->fetch_size) {
138 addr += dprm->offset;
139 dprm->fetch_size(regs, (void *)addr, dest);
140 } else
141 *(string_size *)dest = 0;
142}
143
144static __kprobes void update_deref_fetch_param(struct deref_fetch_param *data)
145{
146 if (CHECK_FETCH_FUNCS(deref, data->orig.fn))
147 update_deref_fetch_param(data->orig.data);
148 else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn))
149 update_symbol_cache(data->orig.data);
150}
151
152static __kprobes void free_deref_fetch_param(struct deref_fetch_param *data)
153{
154 if (CHECK_FETCH_FUNCS(deref, data->orig.fn))
155 free_deref_fetch_param(data->orig.data);
156 else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn))
157 free_symbol_cache(data->orig.data);
158 kfree(data);
159}
160
161/* Bitfield fetch function */
162struct bitfield_fetch_param {
163 struct fetch_param orig;
164 unsigned char hi_shift;
165 unsigned char low_shift;
166};
167
168#define DEFINE_FETCH_bitfield(type) \
169__kprobes void FETCH_FUNC_NAME(bitfield, type)(struct pt_regs *regs, \
170 void *data, void *dest) \
171{ \
172 struct bitfield_fetch_param *bprm = data; \
173 type buf = 0; \
174 call_fetch(&bprm->orig, regs, &buf); \
175 if (buf) { \
176 buf <<= bprm->hi_shift; \
177 buf >>= bprm->low_shift; \
178 } \
179 *(type *)dest = buf; \
180}
181
182DEFINE_BASIC_FETCH_FUNCS(bitfield)
183#define fetch_bitfield_string NULL
184#define fetch_bitfield_string_size NULL
185
186static __kprobes void
187update_bitfield_fetch_param(struct bitfield_fetch_param *data)
188{
189 /*
190 * Don't check the bitfield itself, because this must be the
191 * last fetch function.
192 */
193 if (CHECK_FETCH_FUNCS(deref, data->orig.fn))
194 update_deref_fetch_param(data->orig.data);
195 else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn))
196 update_symbol_cache(data->orig.data);
197}
198
199static __kprobes void
200free_bitfield_fetch_param(struct bitfield_fetch_param *data)
201{
202 /*
203 * Don't check the bitfield itself, because this must be the
204 * last fetch function.
205 */
206 if (CHECK_FETCH_FUNCS(deref, data->orig.fn))
207 free_deref_fetch_param(data->orig.data);
208 else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn))
209 free_symbol_cache(data->orig.data);
210
211 kfree(data);
212}
213
214static const struct fetch_type *find_fetch_type(const char *type,
215 const struct fetch_type *ftbl)
216{
217 int i;
218
219 if (!type)
220 type = DEFAULT_FETCH_TYPE_STR;
221
222 /* Special case: bitfield */
223 if (*type == 'b') {
224 unsigned long bs;
225
226 type = strchr(type, '/');
227 if (!type)
228 goto fail;
229
230 type++;
231 if (kstrtoul(type, 0, &bs))
232 goto fail;
233
234 switch (bs) {
235 case 8:
236 return find_fetch_type("u8", ftbl);
237 case 16:
238 return find_fetch_type("u16", ftbl);
239 case 32:
240 return find_fetch_type("u32", ftbl);
241 case 64:
242 return find_fetch_type("u64", ftbl);
243 default:
244 goto fail;
245 }
246 }
247
248 for (i = 0; ftbl[i].name; i++) {
249 if (strcmp(type, ftbl[i].name) == 0)
250 return &ftbl[i];
251 }
252
253fail:
254 return NULL;
255}
256
257/* Special function : only accept unsigned long */
258static __kprobes void fetch_kernel_stack_address(struct pt_regs *regs,
259 void *dummy, void *dest)
260{
261 *(unsigned long *)dest = kernel_stack_pointer(regs);
262}
263
264static __kprobes void fetch_user_stack_address(struct pt_regs *regs,
265 void *dummy, void *dest)
266{
267 *(unsigned long *)dest = user_stack_pointer(regs);
268}
269
270static fetch_func_t get_fetch_size_function(const struct fetch_type *type,
271 fetch_func_t orig_fn,
272 const struct fetch_type *ftbl)
273{
274 int i;
275
276 if (type != &ftbl[FETCH_TYPE_STRING])
277 return NULL; /* Only string type needs size function */
278
279 for (i = 0; i < FETCH_MTD_END; i++)
280 if (type->fetch[i] == orig_fn)
281 return ftbl[FETCH_TYPE_STRSIZE].fetch[i];
282
283 WARN_ON(1); /* This should not happen */
284
285 return NULL;
286}
287
288/* Split symbol and offset. */
289int traceprobe_split_symbol_offset(char *symbol, unsigned long *offset)
290{
291 char *tmp;
292 int ret;
293
294 if (!offset)
295 return -EINVAL;
296
297 tmp = strchr(symbol, '+');
298 if (tmp) {
299 /* skip sign because kstrtoul doesn't accept '+' */
300 ret = kstrtoul(tmp + 1, 0, offset);
301 if (ret)
302 return ret;
303
304 *tmp = '\0';
305 } else
306 *offset = 0;
307
308 return 0;
309}
310
311#define PARAM_MAX_STACK (THREAD_SIZE / sizeof(unsigned long))
312
313static int parse_probe_vars(char *arg, const struct fetch_type *t,
314 struct fetch_param *f, bool is_return,
315 bool is_kprobe)
316{
317 int ret = 0;
318 unsigned long param;
319
320 if (strcmp(arg, "retval") == 0) {
321 if (is_return)
322 f->fn = t->fetch[FETCH_MTD_retval];
323 else
324 ret = -EINVAL;
325 } else if (strncmp(arg, "stack", 5) == 0) {
326 if (arg[5] == '\0') {
327 if (strcmp(t->name, DEFAULT_FETCH_TYPE_STR))
328 return -EINVAL;
329
330 if (is_kprobe)
331 f->fn = fetch_kernel_stack_address;
332 else
333 f->fn = fetch_user_stack_address;
334 } else if (isdigit(arg[5])) {
335 ret = kstrtoul(arg + 5, 10, ¶m);
336 if (ret || (is_kprobe && param > PARAM_MAX_STACK))
337 ret = -EINVAL;
338 else {
339 f->fn = t->fetch[FETCH_MTD_stack];
340 f->data = (void *)param;
341 }
342 } else
343 ret = -EINVAL;
344 } else
345 ret = -EINVAL;
346
347 return ret;
348}
349
350/* Recursive argument parser */
351static int parse_probe_arg(char *arg, const struct fetch_type *t,
352 struct fetch_param *f, bool is_return, bool is_kprobe)
353{
354 const struct fetch_type *ftbl;
355 unsigned long param;
356 long offset;
357 char *tmp;
358 int ret = 0;
359
360 ftbl = is_kprobe ? kprobes_fetch_type_table : uprobes_fetch_type_table;
361 BUG_ON(ftbl == NULL);
362
363 switch (arg[0]) {
364 case '$':
365 ret = parse_probe_vars(arg + 1, t, f, is_return, is_kprobe);
366 break;
367
368 case '%': /* named register */
369 ret = regs_query_register_offset(arg + 1);
370 if (ret >= 0) {
371 f->fn = t->fetch[FETCH_MTD_reg];
372 f->data = (void *)(unsigned long)ret;
373 ret = 0;
374 }
375 break;
376
377 case '@': /* memory, file-offset or symbol */
378 if (isdigit(arg[1])) {
379 ret = kstrtoul(arg + 1, 0, ¶m);
380 if (ret)
381 break;
382
383 f->fn = t->fetch[FETCH_MTD_memory];
384 f->data = (void *)param;
385 } else if (arg[1] == '+') {
386 /* kprobes don't support file offsets */
387 if (is_kprobe)
388 return -EINVAL;
389
390 ret = kstrtol(arg + 2, 0, &offset);
391 if (ret)
392 break;
393
394 f->fn = t->fetch[FETCH_MTD_file_offset];
395 f->data = (void *)offset;
396 } else {
397 /* uprobes don't support symbols */
398 if (!is_kprobe)
399 return -EINVAL;
400
401 ret = traceprobe_split_symbol_offset(arg + 1, &offset);
402 if (ret)
403 break;
404
405 f->data = alloc_symbol_cache(arg + 1, offset);
406 if (f->data)
407 f->fn = t->fetch[FETCH_MTD_symbol];
408 }
409 break;
410
411 case '+': /* deref memory */
412 arg++; /* Skip '+', because kstrtol() rejects it. */
413 case '-':
414 tmp = strchr(arg, '(');
415 if (!tmp)
416 break;
417
418 *tmp = '\0';
419 ret = kstrtol(arg, 0, &offset);
420
421 if (ret)
422 break;
423
424 arg = tmp + 1;
425 tmp = strrchr(arg, ')');
426
427 if (tmp) {
428 struct deref_fetch_param *dprm;
429 const struct fetch_type *t2;
430
431 t2 = find_fetch_type(NULL, ftbl);
432 *tmp = '\0';
433 dprm = kzalloc(sizeof(struct deref_fetch_param), GFP_KERNEL);
434
435 if (!dprm)
436 return -ENOMEM;
437
438 dprm->offset = offset;
439 dprm->fetch = t->fetch[FETCH_MTD_memory];
440 dprm->fetch_size = get_fetch_size_function(t,
441 dprm->fetch, ftbl);
442 ret = parse_probe_arg(arg, t2, &dprm->orig, is_return,
443 is_kprobe);
444 if (ret)
445 kfree(dprm);
446 else {
447 f->fn = t->fetch[FETCH_MTD_deref];
448 f->data = (void *)dprm;
449 }
450 }
451 break;
452 }
453 if (!ret && !f->fn) { /* Parsed, but do not find fetch method */
454 pr_info("%s type has no corresponding fetch method.\n", t->name);
455 ret = -EINVAL;
456 }
457
458 return ret;
459}
460
461#define BYTES_TO_BITS(nb) ((BITS_PER_LONG * (nb)) / sizeof(long))
462
463/* Bitfield type needs to be parsed into a fetch function */
464static int __parse_bitfield_probe_arg(const char *bf,
465 const struct fetch_type *t,
466 struct fetch_param *f)
467{
468 struct bitfield_fetch_param *bprm;
469 unsigned long bw, bo;
470 char *tail;
471
472 if (*bf != 'b')
473 return 0;
474
475 bprm = kzalloc(sizeof(*bprm), GFP_KERNEL);
476 if (!bprm)
477 return -ENOMEM;
478
479 bprm->orig = *f;
480 f->fn = t->fetch[FETCH_MTD_bitfield];
481 f->data = (void *)bprm;
482 bw = simple_strtoul(bf + 1, &tail, 0); /* Use simple one */
483
484 if (bw == 0 || *tail != '@')
485 return -EINVAL;
486
487 bf = tail + 1;
488 bo = simple_strtoul(bf, &tail, 0);
489
490 if (tail == bf || *tail != '/')
491 return -EINVAL;
492
493 bprm->hi_shift = BYTES_TO_BITS(t->size) - (bw + bo);
494 bprm->low_shift = bprm->hi_shift + bo;
495
496 return (BYTES_TO_BITS(t->size) < (bw + bo)) ? -EINVAL : 0;
497}
498
499/* String length checking wrapper */
500int traceprobe_parse_probe_arg(char *arg, ssize_t *size,
501 struct probe_arg *parg, bool is_return, bool is_kprobe)
502{
503 const struct fetch_type *ftbl;
504 const char *t;
505 int ret;
506
507 ftbl = is_kprobe ? kprobes_fetch_type_table : uprobes_fetch_type_table;
508 BUG_ON(ftbl == NULL);
509
510 if (strlen(arg) > MAX_ARGSTR_LEN) {
511 pr_info("Argument is too long.: %s\n", arg);
512 return -ENOSPC;
513 }
514 parg->comm = kstrdup(arg, GFP_KERNEL);
515 if (!parg->comm) {
516 pr_info("Failed to allocate memory for command '%s'.\n", arg);
517 return -ENOMEM;
518 }
519 t = strchr(parg->comm, ':');
520 if (t) {
521 arg[t - parg->comm] = '\0';
522 t++;
523 }
524 parg->type = find_fetch_type(t, ftbl);
525 if (!parg->type) {
526 pr_info("Unsupported type: %s\n", t);
527 return -EINVAL;
528 }
529 parg->offset = *size;
530 *size += parg->type->size;
531 ret = parse_probe_arg(arg, parg->type, &parg->fetch, is_return, is_kprobe);
532
533 if (ret >= 0 && t != NULL)
534 ret = __parse_bitfield_probe_arg(t, parg->type, &parg->fetch);
535
536 if (ret >= 0) {
537 parg->fetch_size.fn = get_fetch_size_function(parg->type,
538 parg->fetch.fn,
539 ftbl);
540 parg->fetch_size.data = parg->fetch.data;
541 }
542
543 return ret;
544}
545
546/* Return 1 if name is reserved or already used by another argument */
547int traceprobe_conflict_field_name(const char *name,
548 struct probe_arg *args, int narg)
549{
550 int i;
551
552 for (i = 0; i < ARRAY_SIZE(reserved_field_names); i++)
553 if (strcmp(reserved_field_names[i], name) == 0)
554 return 1;
555
556 for (i = 0; i < narg; i++)
557 if (strcmp(args[i].name, name) == 0)
558 return 1;
559
560 return 0;
561}
562
563void traceprobe_update_arg(struct probe_arg *arg)
564{
565 if (CHECK_FETCH_FUNCS(bitfield, arg->fetch.fn))
566 update_bitfield_fetch_param(arg->fetch.data);
567 else if (CHECK_FETCH_FUNCS(deref, arg->fetch.fn))
568 update_deref_fetch_param(arg->fetch.data);
569 else if (CHECK_FETCH_FUNCS(symbol, arg->fetch.fn))
570 update_symbol_cache(arg->fetch.data);
571}
572
573void traceprobe_free_probe_arg(struct probe_arg *arg)
574{
575 if (CHECK_FETCH_FUNCS(bitfield, arg->fetch.fn))
576 free_bitfield_fetch_param(arg->fetch.data);
577 else if (CHECK_FETCH_FUNCS(deref, arg->fetch.fn))
578 free_deref_fetch_param(arg->fetch.data);
579 else if (CHECK_FETCH_FUNCS(symbol, arg->fetch.fn))
580 free_symbol_cache(arg->fetch.data);
581
582 kfree(arg->name);
583 kfree(arg->comm);
584}
585
586int traceprobe_command(const char *buf, int (*createfn)(int, char **))
587{
588 char **argv;
589 int argc, ret;
590
591 argc = 0;
592 ret = 0;
593 argv = argv_split(GFP_KERNEL, buf, &argc);
594 if (!argv)
595 return -ENOMEM;
596
597 if (argc)
598 ret = createfn(argc, argv);
599
600 argv_free(argv);
601
602 return ret;
603}
604
605#define WRITE_BUFSIZE 4096
606
607ssize_t traceprobe_probes_write(struct file *file, const char __user *buffer,
608 size_t count, loff_t *ppos,
609 int (*createfn)(int, char **))
610{
611 char *kbuf, *tmp;
612 int ret = 0;
613 size_t done = 0;
614 size_t size;
615
616 kbuf = kmalloc(WRITE_BUFSIZE, GFP_KERNEL);
617 if (!kbuf)
618 return -ENOMEM;
619
620 while (done < count) {
621 size = count - done;
622
623 if (size >= WRITE_BUFSIZE)
624 size = WRITE_BUFSIZE - 1;
625
626 if (copy_from_user(kbuf, buffer + done, size)) {
627 ret = -EFAULT;
628 goto out;
629 }
630 kbuf[size] = '\0';
631 tmp = strchr(kbuf, '\n');
632
633 if (tmp) {
634 *tmp = '\0';
635 size = tmp - kbuf + 1;
636 } else if (done + size < count) {
637 pr_warning("Line length is too long: "
638 "Should be less than %d.", WRITE_BUFSIZE);
639 ret = -EINVAL;
640 goto out;
641 }
642 done += size;
643 /* Remove comments */
644 tmp = strchr(kbuf, '#');
645
646 if (tmp)
647 *tmp = '\0';
648
649 ret = traceprobe_command(kbuf, createfn);
650 if (ret)
651 goto out;
652 }
653 ret = done;
654
655out:
656 kfree(kbuf);
657
658 return ret;
659}
660
661static int __set_print_fmt(struct trace_probe *tp, char *buf, int len,
662 bool is_return)
663{
664 int i;
665 int pos = 0;
666
667 const char *fmt, *arg;
668
669 if (!is_return) {
670 fmt = "(%lx)";
671 arg = "REC->" FIELD_STRING_IP;
672 } else {
673 fmt = "(%lx <- %lx)";
674 arg = "REC->" FIELD_STRING_FUNC ", REC->" FIELD_STRING_RETIP;
675 }
676
677 /* When len=0, we just calculate the needed length */
678#define LEN_OR_ZERO (len ? len - pos : 0)
679
680 pos += snprintf(buf + pos, LEN_OR_ZERO, "\"%s", fmt);
681
682 for (i = 0; i < tp->nr_args; i++) {
683 pos += snprintf(buf + pos, LEN_OR_ZERO, " %s=%s",
684 tp->args[i].name, tp->args[i].type->fmt);
685 }
686
687 pos += snprintf(buf + pos, LEN_OR_ZERO, "\", %s", arg);
688
689 for (i = 0; i < tp->nr_args; i++) {
690 if (strcmp(tp->args[i].type->name, "string") == 0)
691 pos += snprintf(buf + pos, LEN_OR_ZERO,
692 ", __get_str(%s)",
693 tp->args[i].name);
694 else
695 pos += snprintf(buf + pos, LEN_OR_ZERO, ", REC->%s",
696 tp->args[i].name);
697 }
698
699#undef LEN_OR_ZERO
700
701 /* return the length of print_fmt */
702 return pos;
703}
704
705int set_print_fmt(struct trace_probe *tp, bool is_return)
706{
707 int len;
708 char *print_fmt;
709
710 /* First: called with 0 length to calculate the needed length */
711 len = __set_print_fmt(tp, NULL, 0, is_return);
712 print_fmt = kmalloc(len + 1, GFP_KERNEL);
713 if (!print_fmt)
714 return -ENOMEM;
715
716 /* Second: actually write the @print_fmt */
717 __set_print_fmt(tp, print_fmt, len + 1, is_return);
718 tp->call.print_fmt = print_fmt;
719
720 return 0;
721}