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tracing/probes: Support function parameters if BTF is available
[linux-2.6-block.git] / kernel / trace / trace_probe.c
CommitLineData
bcea3f96 1// SPDX-License-Identifier: GPL-2.0
8ab83f56
SD		 2/*
3 * Common code for probe-based Dynamic events.
4 *
8ab83f56
SD		 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 */
72576341 12#define pr_fmt(fmt) "trace_probe: " fmt
8ab83f56 13
b576e097
MHG		 14#include <linux/bpf.h>
15
8ab83f56
SD		 16#include "trace_probe.h"
17
ab105a4f
MH		 18#undef C
19#define C(a, b) b
20
21static const char *trace_probe_err_text[] = { ERRORS };
22
08416252 23static const char *reserved_field_names[] = {
8ab83f56
SD		 24 "common_type",
25 "common_flags",
26 "common_preempt_count",
27 "common_pid",
28 "common_tgid",
29 FIELD_STRING_IP,
30 FIELD_STRING_RETIP,
31 FIELD_STRING_FUNC,
32};
33
8ab83f56 34/* Printing in basic type function template */
17ce3dc7 35#define DEFINE_BASIC_PRINT_TYPE_FUNC(tname, type, fmt) \
56de7630 36int PRINT_TYPE_FUNC_NAME(tname)(struct trace_seq *s, void *data, void *ent)\
8ab83f56 37{ \
56de7630 38 trace_seq_printf(s, fmt, *(type *)data); \
d2b0191a 39 return !trace_seq_has_overflowed(s); \
8ab83f56 40} \
7bfbc63e 41const char PRINT_TYPE_FMT_NAME(tname)[] = fmt;
8ab83f56 42
bdca79c2
MH		 43DEFINE_BASIC_PRINT_TYPE_FUNC(u8, u8, "%u")
44DEFINE_BASIC_PRINT_TYPE_FUNC(u16, u16, "%u")
45DEFINE_BASIC_PRINT_TYPE_FUNC(u32, u32, "%u")
46DEFINE_BASIC_PRINT_TYPE_FUNC(u64, u64, "%Lu")
17ce3dc7
MH		 47DEFINE_BASIC_PRINT_TYPE_FUNC(s8, s8, "%d")
48DEFINE_BASIC_PRINT_TYPE_FUNC(s16, s16, "%d")
49DEFINE_BASIC_PRINT_TYPE_FUNC(s32, s32, "%d")
50DEFINE_BASIC_PRINT_TYPE_FUNC(s64, s64, "%Ld")
51DEFINE_BASIC_PRINT_TYPE_FUNC(x8, u8, "0x%x")
52DEFINE_BASIC_PRINT_TYPE_FUNC(x16, u16, "0x%x")
53DEFINE_BASIC_PRINT_TYPE_FUNC(x32, u32, "0x%x")
54DEFINE_BASIC_PRINT_TYPE_FUNC(x64, u64, "0x%Lx")
8478cca1 55DEFINE_BASIC_PRINT_TYPE_FUNC(char, u8, "'%c'")
8ab83f56 56
60c2e0ce
MH		 57int PRINT_TYPE_FUNC_NAME(symbol)(struct trace_seq *s, void *data, void *ent)
58{
59 trace_seq_printf(s, "%pS", (void *)*(unsigned long *)data);
60 return !trace_seq_has_overflowed(s);
61}
62const char PRINT_TYPE_FMT_NAME(symbol)[] = "%pS";
63
8ab83f56 64/* Print type function for string type */
56de7630 65int PRINT_TYPE_FUNC_NAME(string)(struct trace_seq *s, void *data, void *ent)
8ab83f56
SD		 66{
67 int len = *(u32 *)data >> 16;
68
69 if (!len)
56de7630 70 trace_seq_puts(s, "(fault)");
8ab83f56 71 else
56de7630 72 trace_seq_printf(s, "\"%s\"",
d2b0191a
SRRH		 73 (const char *)get_loc_data(data, ent));
74 return !trace_seq_has_overflowed(s);
8ab83f56
SD		 75}
76
b26c74e1 77const char PRINT_TYPE_FMT_NAME(string)[] = "\\\"%s\\\"";
8ab83f56 78
f451bc89
MH		 79/* Fetch type information table */
80static const struct fetch_type probe_fetch_types[] = {
81 /* Special types */
b26a124c 82 __ASSIGN_FETCH_TYPE("string", string, string, sizeof(u32), 1, 1,
f451bc89 83 "__data_loc char[]"),
b26a124c
MHG		 84 __ASSIGN_FETCH_TYPE("ustring", string, string, sizeof(u32), 1, 1,
85 "__data_loc char[]"),
86 __ASSIGN_FETCH_TYPE("symstr", string, string, sizeof(u32), 1, 1,
88903c46 87 "__data_loc char[]"),
f451bc89
MH		 88 /* Basic types */
89 ASSIGN_FETCH_TYPE(u8, u8, 0),
90 ASSIGN_FETCH_TYPE(u16, u16, 0),
91 ASSIGN_FETCH_TYPE(u32, u32, 0),
92 ASSIGN_FETCH_TYPE(u64, u64, 0),
93 ASSIGN_FETCH_TYPE(s8, u8, 1),
94 ASSIGN_FETCH_TYPE(s16, u16, 1),
95 ASSIGN_FETCH_TYPE(s32, u32, 1),
96 ASSIGN_FETCH_TYPE(s64, u64, 1),
97 ASSIGN_FETCH_TYPE_ALIAS(x8, u8, u8, 0),
98 ASSIGN_FETCH_TYPE_ALIAS(x16, u16, u16, 0),
99 ASSIGN_FETCH_TYPE_ALIAS(x32, u32, u32, 0),
100 ASSIGN_FETCH_TYPE_ALIAS(x64, u64, u64, 0),
8478cca1 101 ASSIGN_FETCH_TYPE_ALIAS(char, u8, u8, 0),
60c2e0ce 102 ASSIGN_FETCH_TYPE_ALIAS(symbol, ADDR_FETCH_TYPE, ADDR_FETCH_TYPE, 0),
f451bc89
MH		 103
104 ASSIGN_FETCH_TYPE_END
105};
106
d4505aa6 107static const struct fetch_type *find_fetch_type(const char *type, unsigned long flags)
8ab83f56
SD		 108{
109 int i;
110
d4505aa6
MHG		 111 /* Reject the symbol/symstr for uprobes */
112 if (type && (flags & TPARG_FL_USER) &&
113 (!strcmp(type, "symbol") || !strcmp(type, "symstr")))
114 return NULL;
115
8ab83f56
SD		 116 if (!type)
117 type = DEFAULT_FETCH_TYPE_STR;
118
119 /* Special case: bitfield */
120 if (*type == 'b') {
121 unsigned long bs;
122
123 type = strchr(type, '/');
124 if (!type)
125 goto fail;
126
127 type++;
bcd83ea6 128 if (kstrtoul(type, 0, &bs))
8ab83f56
SD		 129 goto fail;
130
131 switch (bs) {
132 case 8:
d4505aa6 133 return find_fetch_type("u8", flags);
8ab83f56 134 case 16:
d4505aa6 135 return find_fetch_type("u16", flags);
8ab83f56 136 case 32:
d4505aa6 137 return find_fetch_type("u32", flags);
8ab83f56 138 case 64:
d4505aa6 139 return find_fetch_type("u64", flags);
8ab83f56
SD		 140 default:
141 goto fail;
142 }
143 }
144
f451bc89
MH		 145 for (i = 0; probe_fetch_types[i].name; i++) {
146 if (strcmp(type, probe_fetch_types[i].name) == 0)
147 return &probe_fetch_types[i];
34fee3a1 148 }
8ab83f56
SD		 149
150fail:
151 return NULL;
152}
153
ab105a4f
MH		 154static struct trace_probe_log trace_probe_log;
155
156void trace_probe_log_init(const char *subsystem, int argc, const char **argv)
157{
158 trace_probe_log.subsystem = subsystem;
159 trace_probe_log.argc = argc;
160 trace_probe_log.argv = argv;
161 trace_probe_log.index = 0;
162}
163
164void trace_probe_log_clear(void)
165{
166 memset(&trace_probe_log, 0, sizeof(trace_probe_log));
167}
168
169void trace_probe_log_set_index(int index)
170{
171 trace_probe_log.index = index;
172}
173
174void __trace_probe_log_err(int offset, int err_type)
175{
176 char *command, *p;
177 int i, len = 0, pos = 0;
178
179 if (!trace_probe_log.argv)
180 return;
181
f2cc020d 182 /* Recalculate the length and allocate buffer */
ab105a4f
MH		 183 for (i = 0; i < trace_probe_log.argc; i++) {
184 if (i == trace_probe_log.index)
185 pos = len;
186 len += strlen(trace_probe_log.argv[i]) + 1;
187 }
188 command = kzalloc(len, GFP_KERNEL);
189 if (!command)
190 return;
191
d2aea95a
MH		 192 if (trace_probe_log.index >= trace_probe_log.argc) {
193 /**
194 * Set the error position is next to the last arg + space.
195 * Note that len includes the terminal null and the cursor
f2cc020d 196 * appears at pos + 1.
d2aea95a
MH		 197 */
198 pos = len;
199 offset = 0;
200 }
201
ab105a4f
MH		 202 /* And make a command string from argv array */
203 p = command;
204 for (i = 0; i < trace_probe_log.argc; i++) {
205 len = strlen(trace_probe_log.argv[i]);
206 strcpy(p, trace_probe_log.argv[i]);
207 p[len] = ' ';
208 p += len + 1;
209 }
210 *(p - 1) = '\0';
211
2f754e77 212 tracing_log_err(NULL, trace_probe_log.subsystem, command,
ab105a4f
MH		 213 trace_probe_err_text, err_type, pos + offset);
214
215 kfree(command);
216}
217
8ab83f56 218/* Split symbol and offset. */
c5d343b6 219int traceprobe_split_symbol_offset(char *symbol, long *offset)
8ab83f56
SD		 220{
221 char *tmp;
222 int ret;
223
224 if (!offset)
225 return -EINVAL;
226
c5d343b6 227 tmp = strpbrk(symbol, "+-");
8ab83f56 228 if (tmp) {
c5d343b6 229 ret = kstrtol(tmp, 0, offset);
8ab83f56
SD		 230 if (ret)
231 return ret;
8ab83f56
SD		 232 *tmp = '\0';
233 } else
234 *offset = 0;
235
236 return 0;
237}
238
6212dd29
MH		 239/* @buf must has MAX_EVENT_NAME_LEN size */
240int traceprobe_parse_event_name(const char **pevent, const char **pgroup,
ab105a4f 241 char *buf, int offset)
6212dd29
MH		 242{
243 const char *slash, *event = *pevent;
dec65d79 244 int len;
6212dd29
MH		 245
246 slash = strchr(event, '/');
bc1b9734
SRV		 247 if (!slash)
248 slash = strchr(event, '.');
249
6212dd29
MH		 250 if (slash) {
251 if (slash == event) {
ab105a4f 252 trace_probe_log_err(offset, NO_GROUP_NAME);
6212dd29
MH		 253 return -EINVAL;
254 }
255 if (slash - event + 1 > MAX_EVENT_NAME_LEN) {
ab105a4f
MH		 256 trace_probe_log_err(offset, GROUP_TOO_LONG);
257 return -EINVAL;
6212dd29
MH		 258 }
259 strlcpy(buf, event, slash - event + 1);
575b76cb 260 if (!is_good_system_name(buf)) {
ab105a4f 261 trace_probe_log_err(offset, BAD_GROUP_NAME);
5b7a9622
MH		 262 return -EINVAL;
263 }
6212dd29
MH		 264 *pgroup = buf;
265 *pevent = slash + 1;
ab105a4f 266 offset += slash - event + 1;
dec65d79 267 event = *pevent;
6212dd29 268 }
dec65d79
MH		 269 len = strlen(event);
270 if (len == 0) {
95c104c3
LY		 271 if (slash) {
272 *pevent = NULL;
273 return 0;
274 }
ab105a4f 275 trace_probe_log_err(offset, NO_EVENT_NAME);
6212dd29 276 return -EINVAL;
dec65d79 277 } else if (len > MAX_EVENT_NAME_LEN) {
ab105a4f
MH		 278 trace_probe_log_err(offset, EVENT_TOO_LONG);
279 return -EINVAL;
6212dd29 280 }
5b7a9622 281 if (!is_good_name(event)) {
ab105a4f 282 trace_probe_log_err(offset, BAD_EVENT_NAME);
5b7a9622
MH		 283 return -EINVAL;
284 }
6212dd29
MH		 285 return 0;
286}
287
1b8b0cd7
MHG		 288static int parse_trace_event_arg(char *arg, struct fetch_insn *code,
289 struct traceprobe_parse_context *ctx)
290{
291 struct ftrace_event_field *field;
292 struct list_head *head;
293
294 head = trace_get_fields(ctx->event);
295 list_for_each_entry(field, head, link) {
296 if (!strcmp(arg, field->name)) {
297 code->op = FETCH_OP_TP_ARG;
298 code->data = field;
299 return 0;
300 }
301 }
302 return -ENOENT;
303}
304
b576e097
MHG		 305#ifdef CONFIG_PROBE_EVENTS_BTF_ARGS
306
307static struct btf *traceprobe_get_btf(void)
308{
309 struct btf *btf = bpf_get_btf_vmlinux();
310
311 if (IS_ERR_OR_NULL(btf))
312 return NULL;
313
314 return btf;
315}
316
317static u32 btf_type_int(const struct btf_type *t)
318{
319 return *(u32 *)(t + 1);
320}
321
322static const char *type_from_btf_id(struct btf *btf, s32 id)
323{
324 const struct btf_type *t;
325 u32 intdata;
326 s32 tid;
327
328 /* TODO: const char * could be converted as a string */
329 t = btf_type_skip_modifiers(btf, id, &tid);
330
331 switch (BTF_INFO_KIND(t->info)) {
332 case BTF_KIND_ENUM:
333 /* enum is "int", so convert to "s32" */
334 return "s32";
335 case BTF_KIND_ENUM64:
336 return "s64";
337 case BTF_KIND_PTR:
338 /* pointer will be converted to "x??" */
339 if (IS_ENABLED(CONFIG_64BIT))
340 return "x64";
341 else
342 return "x32";
343 case BTF_KIND_INT:
344 intdata = btf_type_int(t);
345 if (BTF_INT_ENCODING(intdata) & BTF_INT_SIGNED) {
346 switch (BTF_INT_BITS(intdata)) {
347 case 8:
348 return "s8";
349 case 16:
350 return "s16";
351 case 32:
352 return "s32";
353 case 64:
354 return "s64";
355 }
356 } else { /* unsigned */
357 switch (BTF_INT_BITS(intdata)) {
358 case 8:
359 return "u8";
360 case 16:
361 return "u16";
362 case 32:
363 return "u32";
364 case 64:
365 return "u64";
366 }
367 }
368 }
369 /* TODO: support other types */
370
371 return NULL;
372}
373
374static const struct btf_param *find_btf_func_param(const char *funcname, s32 *nr)
375{
376 struct btf *btf = traceprobe_get_btf();
377 const struct btf_type *t;
378 s32 id;
379
380 if (!btf || !funcname || !nr)
381 return ERR_PTR(-EINVAL);
382
383 id = btf_find_by_name_kind(btf, funcname, BTF_KIND_FUNC);
384 if (id <= 0)
385 return ERR_PTR(-ENOENT);
386
387 /* Get BTF_KIND_FUNC type */
388 t = btf_type_by_id(btf, id);
389 if (!btf_type_is_func(t))
390 return ERR_PTR(-ENOENT);
391
392 /* The type of BTF_KIND_FUNC is BTF_KIND_FUNC_PROTO */
393 t = btf_type_by_id(btf, t->type);
394 if (!btf_type_is_func_proto(t))
395 return ERR_PTR(-ENOENT);
396
397 *nr = btf_type_vlen(t);
398
399 if (*nr)
400 return (const struct btf_param *)(t + 1);
401 else
402 return NULL;
403}
404
405static int parse_btf_arg(const char *varname, struct fetch_insn *code,
406 struct traceprobe_parse_context *ctx)
407{
408 struct btf *btf = traceprobe_get_btf();
409 const struct btf_param *params;
410 int i;
411
412 if (!btf) {
413 trace_probe_log_err(ctx->offset, NOSUP_BTFARG);
414 return -EOPNOTSUPP;
415 }
416
417 if (WARN_ON_ONCE(!ctx->funcname))
418 return -EINVAL;
419
420 if (!ctx->params) {
421 params = find_btf_func_param(ctx->funcname, &ctx->nr_params);
422 if (IS_ERR(params)) {
423 trace_probe_log_err(ctx->offset, NO_BTF_ENTRY);
424 return PTR_ERR(params);
425 }
426 ctx->params = params;
427 } else
428 params = ctx->params;
429
430 for (i = 0; i < ctx->nr_params; i++) {
431 const char *name = btf_name_by_offset(btf, params[i].name_off);
432
433 if (name && !strcmp(name, varname)) {
434 code->op = FETCH_OP_ARG;
435 code->param = i;
436 return 0;
437 }
438 }
439 trace_probe_log_err(ctx->offset, NO_BTFARG);
440 return -ENOENT;
441}
442
443static const struct fetch_type *parse_btf_arg_type(int arg_idx,
444 struct traceprobe_parse_context *ctx)
445{
446 struct btf *btf = traceprobe_get_btf();
447 const char *typestr = NULL;
448
449 if (btf && ctx->params)
450 typestr = type_from_btf_id(btf, ctx->params[arg_idx].type);
451
452 return find_fetch_type(typestr, ctx->flags);
453}
454#else
455static struct btf *traceprobe_get_btf(void)
456{
457 return NULL;
458}
459
460static int parse_btf_arg(const char *varname, struct fetch_insn *code,
461 struct traceprobe_parse_context *ctx)
462{
463 trace_probe_log_err(ctx->offset, NOSUP_BTFARG);
464 return -EOPNOTSUPP;
465}
466#define parse_btf_arg_type(idx, ctx) \
467 find_fetch_type(NULL, ctx->flags)
468#endif
469
8ab83f56
SD		 470#define PARAM_MAX_STACK (THREAD_SIZE / sizeof(unsigned long))
471
472static int parse_probe_vars(char *arg, const struct fetch_type *t,
1b8b0cd7
MHG		 473 struct fetch_insn *code,
474 struct traceprobe_parse_context *ctx)
8ab83f56 475{
8ab83f56 476 unsigned long param;
1b8b0cd7 477 int err = TP_ERR_BAD_VAR;
3d739c1f
SRV		 478 int ret = 0;
479 int len;
8ab83f56 480
1b8b0cd7 481 if (ctx->flags & TPARG_FL_TEVENT) {
2673c60e
SRG		 482 if (code->data)
483 return -EFAULT;
1b8b0cd7
MHG		 484 ret = parse_trace_event_arg(arg, code, ctx);
485 if (!ret)
486 return 0;
487 if (strcmp(arg, "comm") == 0 || strcmp(arg, "COMM") == 0) {
488 code->op = FETCH_OP_COMM;
489 return 0;
490 }
491 /* backward compatibility */
492 ctx->offset = 0;
493 goto inval;
494 }
495
496 if (strcmp(arg, "retval") == 0) {
497 if (ctx->flags & TPARG_FL_RETURN) {
53305928 498 code->op = FETCH_OP_RETVAL;
1b8b0cd7 499 return 0;
ab105a4f 500 }
1b8b0cd7
MHG		 501 err = TP_ERR_RETVAL_ON_PROBE;
502 goto inval;
503 }
504
505 len = str_has_prefix(arg, "stack");
506 if (len) {
507
3d739c1f 508 if (arg[len] == '\0') {
53305928 509 code->op = FETCH_OP_STACKP;
1b8b0cd7
MHG		 510 return 0;
511 }
512
513 if (isdigit(arg[len])) {
3d739c1f 514 ret = kstrtoul(arg + len, 10, &param);
1b8b0cd7
MHG		 515 if (ret)
516 goto inval;
517
518 if ((ctx->flags & TPARG_FL_KERNEL) &&
519 param > PARAM_MAX_STACK) {
520 err = TP_ERR_BAD_STACK_NUM;
521 goto inval;
8ab83f56 522 }
1b8b0cd7
MHG		 523 code->op = FETCH_OP_STACK;
524 code->param = (unsigned int)param;
525 return 0;
526 }
527 goto inval;
528 }
529
530 if (strcmp(arg, "comm") == 0 || strcmp(arg, "COMM") == 0) {
53305928 531 code->op = FETCH_OP_COMM;
1b8b0cd7
MHG		 532 return 0;
533 }
534
a1303af5 535#ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API
1b8b0cd7
MHG		 536 len = str_has_prefix(arg, "arg");
537 if (len && tparg_is_function_entry(ctx->flags)) {
3d739c1f 538 ret = kstrtoul(arg + len, 10, &param);
1b8b0cd7
MHG		 539 if (ret)
540 goto inval;
541
542 if (!param || param > PARAM_MAX_STACK) {
543 err = TP_ERR_BAD_ARG_NUM;
544 goto inval;
ab105a4f 545 }
1b8b0cd7 546
a1303af5
MH		 547 code->op = FETCH_OP_ARG;
548 code->param = (unsigned int)param - 1;
e2d0d7b2
MHG		 549 /*
550 * The tracepoint probe will probe a stub function, and the
551 * first parameter of the stub is a dummy and should be ignored.
552 */
1b8b0cd7 553 if (ctx->flags & TPARG_FL_TPOINT)
e2d0d7b2 554 code->param++;
1b8b0cd7
MHG		 555 return 0;
556 }
a1303af5 557#endif
8ab83f56 558
1b8b0cd7
MHG		 559inval:
560 __trace_probe_log_err(ctx->offset, err);
ab105a4f 561 return -EINVAL;
8ab83f56
SD		 562}
563
6218bf9f
MH		 564static int str_to_immediate(char *str, unsigned long *imm)
565{
566 if (isdigit(str[0]))
567 return kstrtoul(str, 0, imm);
568 else if (str[0] == '-')
569 return kstrtol(str, 0, (long *)imm);
570 else if (str[0] == '+')
571 return kstrtol(str + 1, 0, (long *)imm);
572 return -EINVAL;
573}
574
a42e3c4d
MH		 575static int __parse_imm_string(char *str, char **pbuf, int offs)
576{
577 size_t len = strlen(str);
578
579 if (str[len - 1] != '"') {
580 trace_probe_log_err(offs + len, IMMSTR_NO_CLOSE);
581 return -EINVAL;
582 }
583 *pbuf = kstrndup(str, len - 1, GFP_KERNEL);
1c1857d4
XW		 584 if (!*pbuf)
585 return -ENOMEM;
a42e3c4d
MH		 586 return 0;
587}
588
8ab83f56 589/* Recursive argument parser */
53305928
MH		 590static int
591parse_probe_arg(char *arg, const struct fetch_type *type,
592 struct fetch_insn **pcode, struct fetch_insn *end,
1b8b0cd7 593 struct traceprobe_parse_context *ctx)
8ab83f56 594{
53305928 595 struct fetch_insn *code = *pcode;
8ab83f56 596 unsigned long param;
e65f7ae7 597 int deref = FETCH_OP_DEREF;
bf173ca9 598 long offset = 0;
8ab83f56 599 char *tmp;
34fee3a1 600 int ret = 0;
8ab83f56 601
8ab83f56
SD		 602 switch (arg[0]) {
603 case '$':
1b8b0cd7 604 ret = parse_probe_vars(arg + 1, type, code, ctx);
8ab83f56
SD		 605 break;
606
607 case '%': /* named register */
1b8b0cd7 608 if (ctx->flags & (TPARG_FL_TEVENT | TPARG_FL_FPROBE)) {
334e5519 609 /* eprobe and fprobe do not handle registers */
1b8b0cd7 610 trace_probe_log_err(ctx->offset, BAD_VAR);
2673c60e
SRG		 611 break;
612 }
8ab83f56
SD		 613 ret = regs_query_register_offset(arg + 1);
614 if (ret >= 0) {
53305928
MH		 615 code->op = FETCH_OP_REG;
616 code->param = (unsigned int)ret;
8ab83f56 617 ret = 0;
ab105a4f 618 } else
1b8b0cd7 619 trace_probe_log_err(ctx->offset, BAD_REG_NAME);
8ab83f56
SD		 620 break;
621
b7e0bf34 622 case '@': /* memory, file-offset or symbol */
8ab83f56 623 if (isdigit(arg[1])) {
bcd83ea6 624 ret = kstrtoul(arg + 1, 0, &param);
ab105a4f 625 if (ret) {
1b8b0cd7 626 trace_probe_log_err(ctx->offset, BAD_MEM_ADDR);
8ab83f56 627 break;
ab105a4f 628 }
53305928
MH		 629 /* load address */
630 code->op = FETCH_OP_IMM;
631 code->immediate = param;
b7e0bf34
NK		 632 } else if (arg[1] == '+') {
633 /* kprobes don't support file offsets */
1b8b0cd7
MHG		 634 if (ctx->flags & TPARG_FL_KERNEL) {
635 trace_probe_log_err(ctx->offset, FILE_ON_KPROBE);
b7e0bf34 636 return -EINVAL;
ab105a4f 637 }
b7e0bf34 638 ret = kstrtol(arg + 2, 0, &offset);
ab105a4f 639 if (ret) {
1b8b0cd7 640 trace_probe_log_err(ctx->offset, BAD_FILE_OFFS);
b7e0bf34 641 break;
ab105a4f 642 }
b7e0bf34 643
53305928
MH		 644 code->op = FETCH_OP_FOFFS;
645 code->immediate = (unsigned long)offset; // imm64?
8ab83f56 646 } else {
b079d374 647 /* uprobes don't support symbols */
1b8b0cd7
MHG		 648 if (!(ctx->flags & TPARG_FL_KERNEL)) {
649 trace_probe_log_err(ctx->offset, SYM_ON_UPROBE);
b079d374 650 return -EINVAL;
ab105a4f 651 }
a6682814
MH		 652 /* Preserve symbol for updating */
653 code->op = FETCH_NOP_SYMBOL;
654 code->data = kstrdup(arg + 1, GFP_KERNEL);
655 if (!code->data)
656 return -ENOMEM;
ab105a4f 657 if (++code == end) {
1b8b0cd7 658 trace_probe_log_err(ctx->offset, TOO_MANY_OPS);
ab105a4f
MH		 659 return -EINVAL;
660 }
53305928 661 code->op = FETCH_OP_IMM;
a6682814 662 code->immediate = 0;
8ab83f56 663 }
53305928 664 /* These are fetching from memory */
ab105a4f 665 if (++code == end) {
1b8b0cd7 666 trace_probe_log_err(ctx->offset, TOO_MANY_OPS);
ab105a4f
MH		 667 return -EINVAL;
668 }
53305928
MH		 669 *pcode = code;
670 code->op = FETCH_OP_DEREF;
671 code->offset = offset;
8ab83f56
SD		 672 break;
673
674 case '+': /* deref memory */
8ab83f56 675 case '-':
e65f7ae7
MH		 676 if (arg[1] == 'u') {
677 deref = FETCH_OP_UDEREF;
678 arg[1] = arg[0];
679 arg++;
680 }
681 if (arg[0] == '+')
682 arg++; /* Skip '+', because kstrtol() rejects it. */
8ab83f56 683 tmp = strchr(arg, '(');
ab105a4f 684 if (!tmp) {
1b8b0cd7 685 trace_probe_log_err(ctx->offset, DEREF_NEED_BRACE);
53305928 686 return -EINVAL;
ab105a4f 687 }
8ab83f56 688 *tmp = '\0';
bcd83ea6 689 ret = kstrtol(arg, 0, &offset);
ab105a4f 690 if (ret) {
1b8b0cd7 691 trace_probe_log_err(ctx->offset, BAD_DEREF_OFFS);
8ab83f56 692 break;
ab105a4f 693 }
1b8b0cd7 694 ctx->offset += (tmp + 1 - arg) + (arg[0] != '-' ? 1 : 0);
8ab83f56
SD		 695 arg = tmp + 1;
696 tmp = strrchr(arg, ')');
ab105a4f 697 if (!tmp) {
1b8b0cd7 698 trace_probe_log_err(ctx->offset + strlen(arg),
ab105a4f
MH		 699 DEREF_OPEN_BRACE);
700 return -EINVAL;
701 } else {
1b8b0cd7
MHG		 702 const struct fetch_type *t2 = find_fetch_type(NULL, ctx->flags);
703 int cur_offs = ctx->offset;
8ab83f56 704
8ab83f56 705 *tmp = '\0';
1b8b0cd7 706 ret = parse_probe_arg(arg, t2, &code, end, ctx);
8ab83f56 707 if (ret)
53305928 708 break;
1b8b0cd7 709 ctx->offset = cur_offs;
a42e3c4d
MH		 710 if (code->op == FETCH_OP_COMM ||
711 code->op == FETCH_OP_DATA) {
1b8b0cd7 712 trace_probe_log_err(ctx->offset, COMM_CANT_DEREF);
ab105a4f
MH		 713 return -EINVAL;
714 }
715 if (++code == end) {
1b8b0cd7 716 trace_probe_log_err(ctx->offset, TOO_MANY_OPS);
53305928 717 return -EINVAL;
ab105a4f 718 }
53305928
MH		 719 *pcode = code;
720
e65f7ae7 721 code->op = deref;
53305928 722 code->offset = offset;
8ab83f56
SD		 723 }
724 break;
6218bf9f 725 case '\\': /* Immediate value */
a42e3c4d 726 if (arg[1] == '"') { /* Immediate string */
1b8b0cd7 727 ret = __parse_imm_string(arg + 2, &tmp, ctx->offset + 2);
a42e3c4d
MH		 728 if (ret)
729 break;
730 code->op = FETCH_OP_DATA;
731 code->data = tmp;
732 } else {
733 ret = str_to_immediate(arg + 1, &code->immediate);
734 if (ret)
1b8b0cd7 735 trace_probe_log_err(ctx->offset + 1, BAD_IMM);
a42e3c4d
MH		 736 else
737 code->op = FETCH_OP_IMM;
738 }
6218bf9f 739 break;
b576e097
MHG		 740 default:
741 if (isalpha(arg[0]) || arg[0] == '_') { /* BTF variable */
742 if (!tparg_is_function_entry(ctx->flags)) {
743 trace_probe_log_err(ctx->offset, NOSUP_BTFARG);
744 return -EINVAL;
745 }
746 ret = parse_btf_arg(arg, code, ctx);
747 break;
748 }
8ab83f56 749 }
53305928
MH		 750 if (!ret && code->op == FETCH_OP_NOP) {
751 /* Parsed, but do not find fetch method */
1b8b0cd7 752 trace_probe_log_err(ctx->offset, BAD_FETCH_ARG);
8ab83f56
SD		 753 ret = -EINVAL;
754 }
8ab83f56
SD		 755 return ret;
756}
757
758#define BYTES_TO_BITS(nb) ((BITS_PER_LONG * (nb)) / sizeof(long))
759
760/* Bitfield type needs to be parsed into a fetch function */
761static int __parse_bitfield_probe_arg(const char *bf,
762 const struct fetch_type *t,
53305928 763 struct fetch_insn **pcode)
8ab83f56 764{
53305928 765 struct fetch_insn *code = *pcode;
8ab83f56
SD		 766 unsigned long bw, bo;
767 char *tail;
768
769 if (*bf != 'b')
770 return 0;
771
8ab83f56
SD		 772 bw = simple_strtoul(bf + 1, &tail, 0); /* Use simple one */
773
774 if (bw == 0 || *tail != '@')
775 return -EINVAL;
776
777 bf = tail + 1;
778 bo = simple_strtoul(bf, &tail, 0);
779
780 if (tail == bf || *tail != '/')
781 return -EINVAL;
53305928
MH		 782 code++;
783 if (code->op != FETCH_OP_NOP)
ab105a4f 784 return -EINVAL;
53305928 785 *pcode = code;
8ab83f56 786
53305928
MH		 787 code->op = FETCH_OP_MOD_BF;
788 code->lshift = BYTES_TO_BITS(t->size) - (bw + bo);
789 code->rshift = BYTES_TO_BITS(t->size) - bw;
790 code->basesize = t->size;
8ab83f56
SD		 791
792 return (BYTES_TO_BITS(t->size) < (bw + bo)) ? -EINVAL : 0;
793}
794
795/* String length checking wrapper */
fcd9db51 796static int traceprobe_parse_probe_arg_body(const char *argv, ssize_t *size,
1b8b0cd7
MHG		 797 struct probe_arg *parg,
798 struct traceprobe_parse_context *ctx)
8ab83f56 799{
40b53b77 800 struct fetch_insn *code, *scode, *tmp = NULL;
ab105a4f 801 char *t, *t2, *t3;
40b53b77 802 int ret, len;
1b8b0cd7 803 char *arg;
8ab83f56 804
fcd9db51
SRV		 805 arg = kstrdup(argv, GFP_KERNEL);
806 if (!arg)
807 return -ENOMEM;
808
809 ret = -EINVAL;
ab105a4f
MH		 810 len = strlen(arg);
811 if (len > MAX_ARGSTR_LEN) {
1b8b0cd7 812 trace_probe_log_err(ctx->offset, ARG_TOO_LONG);
fcd9db51 813 goto out;
ab105a4f 814 } else if (len == 0) {
1b8b0cd7 815 trace_probe_log_err(ctx->offset, NO_ARG_BODY);
fcd9db51 816 goto out;
8ab83f56 817 }
ab105a4f 818
fcd9db51 819 ret = -ENOMEM;
8ab83f56 820 parg->comm = kstrdup(arg, GFP_KERNEL);
ab105a4f 821 if (!parg->comm)
fcd9db51 822 goto out;
ab105a4f 823
fcd9db51 824 ret = -EINVAL;
40b53b77 825 t = strchr(arg, ':');
8ab83f56 826 if (t) {
40b53b77
MH		 827 *t = '\0';
828 t2 = strchr(++t, '[');
829 if (t2) {
ab105a4f
MH		 830 *t2++ = '\0';
831 t3 = strchr(t2, ']');
832 if (!t3) {
1b8b0cd7
MHG		 833 int offs = t2 + strlen(t2) - arg;
834
835 trace_probe_log_err(ctx->offset + offs,
ab105a4f 836 ARRAY_NO_CLOSE);
fcd9db51 837 goto out;
ab105a4f 838 } else if (t3[1] != '\0') {
1b8b0cd7 839 trace_probe_log_err(ctx->offset + t3 + 1 - arg,
ab105a4f 840 BAD_ARRAY_SUFFIX);
fcd9db51 841 goto out;
ab105a4f
MH		 842 }
843 *t3 = '\0';
844 if (kstrtouint(t2, 0, &parg->count) || !parg->count) {
1b8b0cd7 845 trace_probe_log_err(ctx->offset + t2 - arg,
ab105a4f 846 BAD_ARRAY_NUM);
fcd9db51 847 goto out;
ab105a4f
MH		 848 }
849 if (parg->count > MAX_ARRAY_LEN) {
1b8b0cd7 850 trace_probe_log_err(ctx->offset + t2 - arg,
ab105a4f 851 ARRAY_TOO_BIG);
fcd9db51 852 goto out;
ab105a4f 853 }
40b53b77 854 }
8ab83f56 855 }
3dd1f7f2 856
a42e3c4d 857 /*
f2cc020d 858 * Since $comm and immediate string can not be dereferenced,
02333de9 859 * we can find those by strcmp. But ignore for eprobes.
a42e3c4d 860 */
1b8b0cd7 861 if (!(ctx->flags & TPARG_FL_TEVENT) &&
ab838444
SRG		 862 (strcmp(arg, "$comm") == 0 || strcmp(arg, "$COMM") == 0 ||
863 strncmp(arg, "\\\"", 2) == 0)) {
3dd1f7f2
MH		 864 /* The type of $comm must be "string", and not an array. */
865 if (parg->count || (t && strcmp(t, "string")))
fcd9db51 866 goto out;
1b8b0cd7 867 parg->type = find_fetch_type("string", ctx->flags);
3dd1f7f2 868 } else
1b8b0cd7 869 parg->type = find_fetch_type(t, ctx->flags);
8ab83f56 870 if (!parg->type) {
1b8b0cd7 871 trace_probe_log_err(ctx->offset + (t ? (t - arg) : 0), BAD_TYPE);
fcd9db51 872 goto out;
8ab83f56
SD		 873 }
874 parg->offset = *size;
40b53b77
MH		 875 *size += parg->type->size * (parg->count ?: 1);
876
fcd9db51 877 ret = -ENOMEM;
40b53b77
MH		 878 if (parg->count) {
879 len = strlen(parg->type->fmttype) + 6;
880 parg->fmt = kmalloc(len, GFP_KERNEL);
881 if (!parg->fmt)
fcd9db51 882 goto out;
40b53b77
MH		 883 snprintf(parg->fmt, len, "%s[%d]", parg->type->fmttype,
884 parg->count);
885 }
8ab83f56 886
8623b006 887 code = tmp = kcalloc(FETCH_INSN_MAX, sizeof(*code), GFP_KERNEL);
53305928 888 if (!code)
fcd9db51 889 goto out;
53305928
MH		 890 code[FETCH_INSN_MAX - 1].op = FETCH_OP_END;
891
892 ret = parse_probe_arg(arg, parg->type, &code, &code[FETCH_INSN_MAX - 1],
1b8b0cd7 893 ctx);
53305928
MH		 894 if (ret)
895 goto fail;
896
b576e097
MHG		 897 /* Update storing type if BTF is available */
898 if (IS_ENABLED(CONFIG_PROBE_EVENTS_BTF_ARGS) &&
899 !t && code->op == FETCH_OP_ARG)
900 parg->type = parse_btf_arg_type(code->param, ctx);
901
fcd9db51 902 ret = -EINVAL;
53305928 903 /* Store operation */
b26a124c
MHG		 904 if (parg->type->is_string) {
905 if (!strcmp(parg->type->name, "symstr")) {
906 if (code->op != FETCH_OP_REG && code->op != FETCH_OP_STACK &&
907 code->op != FETCH_OP_RETVAL && code->op != FETCH_OP_ARG &&
908 code->op != FETCH_OP_DEREF && code->op != FETCH_OP_TP_ARG) {
1b8b0cd7 909 trace_probe_log_err(ctx->offset + (t ? (t - arg) : 0),
b26a124c
MHG		 910 BAD_SYMSTRING);
911 goto fail;
912 }
913 } else {
914 if (code->op != FETCH_OP_DEREF && code->op != FETCH_OP_UDEREF &&
915 code->op != FETCH_OP_IMM && code->op != FETCH_OP_COMM &&
916 code->op != FETCH_OP_DATA && code->op != FETCH_OP_TP_ARG) {
1b8b0cd7 917 trace_probe_log_err(ctx->offset + (t ? (t - arg) : 0),
b26a124c
MHG		 918 BAD_STRING);
919 goto fail;
920 }
53305928 921 }
b26a124c
MHG		 922 if (!strcmp(parg->type->name, "symstr") ||
923 (code->op == FETCH_OP_IMM || code->op == FETCH_OP_COMM ||
7491e2c4
TSV		 924 code->op == FETCH_OP_DATA) || code->op == FETCH_OP_TP_ARG ||
925 parg->count) {
40b53b77 926 /*
a42e3c4d
MH		 927 * IMM, DATA and COMM is pointing actual address, those
928 * must be kept, and if parg->count != 0, this is an
929 * array of string pointers instead of string address
930 * itself.
b26a124c
MHG		 931 * For the symstr, it doesn't need to dereference, thus
932 * it just get the value.
40b53b77 933 */
53305928 934 code++;
40b53b77 935 if (code->op != FETCH_OP_NOP) {
1b8b0cd7 936 trace_probe_log_err(ctx->offset, TOO_MANY_OPS);
40b53b77
MH		 937 goto fail;
938 }
939 }
88903c46 940 /* If op == DEREF, replace it with STRING */
e65f7ae7
MH		 941 if (!strcmp(parg->type->name, "ustring") ||
942 code->op == FETCH_OP_UDEREF)
88903c46 943 code->op = FETCH_OP_ST_USTRING;
b26a124c
MHG		 944 else if (!strcmp(parg->type->name, "symstr"))
945 code->op = FETCH_OP_ST_SYMSTR;
88903c46
MH		 946 else
947 code->op = FETCH_OP_ST_STRING;
40b53b77 948 code->size = parg->type->size;
53305928
MH		 949 parg->dynamic = true;
950 } else if (code->op == FETCH_OP_DEREF) {
951 code->op = FETCH_OP_ST_MEM;
952 code->size = parg->type->size;
e65f7ae7
MH		 953 } else if (code->op == FETCH_OP_UDEREF) {
954 code->op = FETCH_OP_ST_UMEM;
955 code->size = parg->type->size;
53305928
MH		 956 } else {
957 code++;
958 if (code->op != FETCH_OP_NOP) {
1b8b0cd7 959 trace_probe_log_err(ctx->offset, TOO_MANY_OPS);
53305928
MH		 960 goto fail;
961 }
962 code->op = FETCH_OP_ST_RAW;
963 code->size = parg->type->size;
964 }
40b53b77 965 scode = code;
53305928
MH		 966 /* Modify operation */
967 if (t != NULL) {
968 ret = __parse_bitfield_probe_arg(t, parg->type, &code);
ab105a4f 969 if (ret) {
1b8b0cd7 970 trace_probe_log_err(ctx->offset + t - arg, BAD_BITFIELD);
53305928 971 goto fail;
ab105a4f 972 }
8ab83f56 973 }
fcd9db51 974 ret = -EINVAL;
40b53b77
MH		 975 /* Loop(Array) operation */
976 if (parg->count) {
977 if (scode->op != FETCH_OP_ST_MEM &&
88903c46
MH		 978 scode->op != FETCH_OP_ST_STRING &&
979 scode->op != FETCH_OP_ST_USTRING) {
1b8b0cd7 980 trace_probe_log_err(ctx->offset + (t ? (t - arg) : 0),
ab105a4f 981 BAD_STRING);
40b53b77
MH		 982 goto fail;
983 }
984 code++;
985 if (code->op != FETCH_OP_NOP) {
1b8b0cd7 986 trace_probe_log_err(ctx->offset, TOO_MANY_OPS);
40b53b77
MH		 987 goto fail;
988 }
989 code->op = FETCH_OP_LP_ARRAY;
990 code->param = parg->count;
991 }
53305928
MH		 992 code++;
993 code->op = FETCH_OP_END;
994
fcd9db51 995 ret = 0;
53305928 996 /* Shrink down the code buffer */
8623b006 997 parg->code = kcalloc(code - tmp + 1, sizeof(*code), GFP_KERNEL);
53305928
MH		 998 if (!parg->code)
999 ret = -ENOMEM;
1000 else
1001 memcpy(parg->code, tmp, sizeof(*code) * (code - tmp + 1));
1002
1003fail:
a6682814
MH		 1004 if (ret) {
1005 for (code = tmp; code < tmp + FETCH_INSN_MAX; code++)
a42e3c4d
MH		 1006 if (code->op == FETCH_NOP_SYMBOL ||
1007 code->op == FETCH_OP_DATA)
a6682814
MH		 1008 kfree(code->data);
1009 }
53305928 1010 kfree(tmp);
fcd9db51
SRV		 1011out:
1012 kfree(arg);
8ab83f56
SD		 1013
1014 return ret;
1015}
1016
1017/* Return 1 if name is reserved or already used by another argument */
d00bbea9
MH		 1018static int traceprobe_conflict_field_name(const char *name,
1019 struct probe_arg *args, int narg)
8ab83f56
SD		 1020{
1021 int i;
1022
1023 for (i = 0; i < ARRAY_SIZE(reserved_field_names); i++)
1024 if (strcmp(reserved_field_names[i], name) == 0)
1025 return 1;
1026
1027 for (i = 0; i < narg; i++)
1028 if (strcmp(args[i].name, name) == 0)
1029 return 1;
1030
1031 return 0;
1032}
1033
b576e097
MHG		 1034static char *generate_probe_arg_name(const char *arg, int idx)
1035{
1036 char *name = NULL;
1037 const char *end;
1038
1039 /*
1040 * If argument name is omitted, try arg as a name (BTF variable)
1041 * or "argN".
1042 */
1043 if (IS_ENABLED(CONFIG_PROBE_EVENTS_BTF_ARGS)) {
1044 end = strchr(arg, ':');
1045 if (!end)
1046 end = arg + strlen(arg);
1047
1048 name = kmemdup_nul(arg, end - arg, GFP_KERNEL);
1049 if (!name || !is_good_name(name)) {
1050 kfree(name);
1051 name = NULL;
1052 }
1053 }
1054
1055 if (!name)
1056 name = kasprintf(GFP_KERNEL, "arg%d", idx + 1);
1057
1058 return name;
1059}
1060
fcd9db51 1061int traceprobe_parse_probe_arg(struct trace_probe *tp, int i, const char *arg,
1b8b0cd7 1062 struct traceprobe_parse_context *ctx)
d00bbea9
MH		 1063{
1064 struct probe_arg *parg = &tp->args[i];
fcd9db51 1065 const char *body;
d00bbea9
MH		 1066
1067 /* Increment count for freeing args in error case */
1068 tp->nr_args++;
1069
1070 body = strchr(arg, '=');
1071 if (body) {
ab105a4f
MH		 1072 if (body - arg > MAX_ARG_NAME_LEN) {
1073 trace_probe_log_err(0, ARG_NAME_TOO_LONG);
1074 return -EINVAL;
1075 } else if (body == arg) {
1076 trace_probe_log_err(0, NO_ARG_NAME);
b4443c17 1077 return -EINVAL;
ab105a4f 1078 }
d00bbea9
MH		 1079 parg->name = kmemdup_nul(arg, body - arg, GFP_KERNEL);
1080 body++;
1081 } else {
b576e097 1082 parg->name = generate_probe_arg_name(arg, i);
d00bbea9
MH		 1083 body = arg;
1084 }
1085 if (!parg->name)
1086 return -ENOMEM;
1087
1088 if (!is_good_name(parg->name)) {
ab105a4f 1089 trace_probe_log_err(0, BAD_ARG_NAME);
d00bbea9
MH		 1090 return -EINVAL;
1091 }
d00bbea9 1092 if (traceprobe_conflict_field_name(parg->name, tp->args, i)) {
ab105a4f 1093 trace_probe_log_err(0, USED_ARG_NAME);
d00bbea9
MH		 1094 return -EINVAL;
1095 }
1b8b0cd7 1096 ctx->offset = body - arg;
d00bbea9 1097 /* Parse fetch argument */
1b8b0cd7 1098 return traceprobe_parse_probe_arg_body(body, &tp->size, parg, ctx);
d00bbea9
MH		 1099}
1100
8ab83f56
SD		 1101void traceprobe_free_probe_arg(struct probe_arg *arg)
1102{
a6682814
MH		 1103 struct fetch_insn *code = arg->code;
1104
1105 while (code && code->op != FETCH_OP_END) {
a42e3c4d
MH		 1106 if (code->op == FETCH_NOP_SYMBOL ||
1107 code->op == FETCH_OP_DATA)
a6682814
MH		 1108 kfree(code->data);
1109 code++;
1110 }
53305928 1111 kfree(arg->code);
8ab83f56
SD		 1112 kfree(arg->name);
1113 kfree(arg->comm);
40b53b77 1114 kfree(arg->fmt);
8ab83f56
SD		 1115}
1116
a6682814
MH		 1117int traceprobe_update_arg(struct probe_arg *arg)
1118{
1119 struct fetch_insn *code = arg->code;
1120 long offset;
1121 char *tmp;
1122 char c;
1123 int ret = 0;
1124
1125 while (code && code->op != FETCH_OP_END) {
1126 if (code->op == FETCH_NOP_SYMBOL) {
1127 if (code[1].op != FETCH_OP_IMM)
1128 return -EINVAL;
1129
ee474b81 1130 tmp = strpbrk(code->data, "+-");
a6682814
MH		 1131 if (tmp)
1132 c = *tmp;
1133 ret = traceprobe_split_symbol_offset(code->data,
1134 &offset);
1135 if (ret)
1136 return ret;
1137
1138 code[1].immediate =
1139 (unsigned long)kallsyms_lookup_name(code->data);
1140 if (tmp)
1141 *tmp = c;
1142 if (!code[1].immediate)
1143 return -ENOENT;
1144 code[1].immediate += offset;
1145 }
1146 code++;
1147 }
1148 return 0;
1149}
1150
40b53b77
MH		 1151/* When len=0, we just calculate the needed length */
1152#define LEN_OR_ZERO (len ? len - pos : 0)
5bf652aa 1153static int __set_print_fmt(struct trace_probe *tp, char *buf, int len,
007517a0 1154 enum probe_print_type ptype)
5bf652aa 1155{
40b53b77
MH		 1156 struct probe_arg *parg;
1157 int i, j;
5bf652aa 1158 int pos = 0;
5bf652aa
NK		 1159 const char *fmt, *arg;
1160
007517a0
SRV		 1161 switch (ptype) {
1162 case PROBE_PRINT_NORMAL:
5bf652aa 1163 fmt = "(%lx)";
b61edd57 1164 arg = ", REC->" FIELD_STRING_IP;
007517a0
SRV		 1165 break;
1166 case PROBE_PRINT_RETURN:
5bf652aa 1167 fmt = "(%lx <- %lx)";
b61edd57 1168 arg = ", REC->" FIELD_STRING_FUNC ", REC->" FIELD_STRING_RETIP;
007517a0 1169 break;
7491e2c4 1170 case PROBE_PRINT_EVENT:
b61edd57
SRG		 1171 fmt = "";
1172 arg = "";
7491e2c4 1173 break;
007517a0
SRV		 1174 default:
1175 WARN_ON_ONCE(1);
1176 return 0;
5bf652aa
NK		 1177 }
1178
5bf652aa
NK		 1179 pos += snprintf(buf + pos, LEN_OR_ZERO, "\"%s", fmt);
1180
1181 for (i = 0; i < tp->nr_args; i++) {
40b53b77
MH		 1182 parg = tp->args + i;
1183 pos += snprintf(buf + pos, LEN_OR_ZERO, " %s=", parg->name);
1184 if (parg->count) {
1185 pos += snprintf(buf + pos, LEN_OR_ZERO, "{%s",
1186 parg->type->fmt);
1187 for (j = 1; j < parg->count; j++)
1188 pos += snprintf(buf + pos, LEN_OR_ZERO, ",%s",
1189 parg->type->fmt);
1190 pos += snprintf(buf + pos, LEN_OR_ZERO, "}");
1191 } else
1192 pos += snprintf(buf + pos, LEN_OR_ZERO, "%s",
1193 parg->type->fmt);
5bf652aa
NK		 1194 }
1195
b61edd57 1196 pos += snprintf(buf + pos, LEN_OR_ZERO, "\"%s", arg);
5bf652aa
NK		 1197
1198 for (i = 0; i < tp->nr_args; i++) {
40b53b77
MH		 1199 parg = tp->args + i;
1200 if (parg->count) {
b26a124c 1201 if (parg->type->is_string)
40b53b77
MH		 1202 fmt = ", __get_str(%s[%d])";
1203 else
1204 fmt = ", REC->%s[%d]";
1205 for (j = 0; j < parg->count; j++)
1206 pos += snprintf(buf + pos, LEN_OR_ZERO,
1207 fmt, parg->name, j);
1208 } else {
b26a124c 1209 if (parg->type->is_string)
40b53b77
MH		 1210 fmt = ", __get_str(%s)";
1211 else
1212 fmt = ", REC->%s";
5bf652aa 1213 pos += snprintf(buf + pos, LEN_OR_ZERO,
40b53b77
MH		 1214 fmt, parg->name);
1215 }
5bf652aa
NK		 1216 }
1217
5bf652aa
NK		 1218 /* return the length of print_fmt */
1219 return pos;
1220}
40b53b77 1221#undef LEN_OR_ZERO
5bf652aa 1222
007517a0 1223int traceprobe_set_print_fmt(struct trace_probe *tp, enum probe_print_type ptype)
5bf652aa 1224{
e3dc9f89 1225 struct trace_event_call *call = trace_probe_event_call(tp);
5bf652aa
NK		 1226 int len;
1227 char *print_fmt;
1228
1229 /* First: called with 0 length to calculate the needed length */
007517a0 1230 len = __set_print_fmt(tp, NULL, 0, ptype);
5bf652aa
NK		 1231 print_fmt = kmalloc(len + 1, GFP_KERNEL);
1232 if (!print_fmt)
1233 return -ENOMEM;
1234
1235 /* Second: actually write the @print_fmt */
007517a0 1236 __set_print_fmt(tp, print_fmt, len + 1, ptype);
e3dc9f89 1237 call->print_fmt = print_fmt;
5bf652aa
NK		 1238
1239 return 0;
1240}
eeb07b06
MH		 1241
1242int traceprobe_define_arg_fields(struct trace_event_call *event_call,
1243 size_t offset, struct trace_probe *tp)
1244{
1245 int ret, i;
1246
1247 /* Set argument names as fields */
1248 for (i = 0; i < tp->nr_args; i++) {
1249 struct probe_arg *parg = &tp->args[i];
40b53b77
MH		 1250 const char *fmt = parg->type->fmttype;
1251 int size = parg->type->size;
1252
1253 if (parg->fmt)
1254 fmt = parg->fmt;
1255 if (parg->count)
1256 size *= parg->count;
1257 ret = trace_define_field(event_call, fmt, parg->name,
1258 offset + parg->offset, size,
eeb07b06
MH		 1259 parg->type->is_signed,
1260 FILTER_OTHER);
1261 if (ret)
1262 return ret;
1263 }
1264 return 0;
1265}
455b2899 1266
ca89bc07
MH		 1267static void trace_probe_event_free(struct trace_probe_event *tpe)
1268{
1269 kfree(tpe->class.system);
1270 kfree(tpe->call.name);
1271 kfree(tpe->call.print_fmt);
1272 kfree(tpe);
1273}
1274
1275int trace_probe_append(struct trace_probe *tp, struct trace_probe *to)
1276{
1277 if (trace_probe_has_sibling(tp))
1278 return -EBUSY;
1279
1280 list_del_init(&tp->list);
1281 trace_probe_event_free(tp->event);
1282
1283 tp->event = to->event;
1284 list_add_tail(&tp->list, trace_probe_probe_list(to));
1285
1286 return 0;
1287}
1288
1289void trace_probe_unlink(struct trace_probe *tp)
1290{
1291 list_del_init(&tp->list);
1292 if (list_empty(trace_probe_probe_list(tp)))
1293 trace_probe_event_free(tp->event);
1294 tp->event = NULL;
1295}
455b2899
MH		 1296
1297void trace_probe_cleanup(struct trace_probe *tp)
1298{
1299 int i;
1300
1301 for (i = 0; i < tp->nr_args; i++)
1302 traceprobe_free_probe_arg(&tp->args[i]);
1303
ca89bc07
MH		 1304 if (tp->event)
1305 trace_probe_unlink(tp);
455b2899
MH		 1306}
1307
1308int trace_probe_init(struct trace_probe *tp, const char *event,
b61387cb 1309 const char *group, bool alloc_filter)
455b2899 1310{
60d53e2c 1311 struct trace_event_call *call;
b61387cb 1312 size_t size = sizeof(struct trace_probe_event);
60d53e2c 1313 int ret = 0;
e3dc9f89 1314
455b2899
MH		 1315 if (!event || !group)
1316 return -EINVAL;
1317
b61387cb
MH		 1318 if (alloc_filter)
1319 size += sizeof(struct trace_uprobe_filter);
1320
1321 tp->event = kzalloc(size, GFP_KERNEL);
60d53e2c 1322 if (!tp->event)
455b2899
MH		 1323 return -ENOMEM;
1324
d59fae6f
MH		 1325 INIT_LIST_HEAD(&tp->event->files);
1326 INIT_LIST_HEAD(&tp->event->class.fields);
1327 INIT_LIST_HEAD(&tp->event->probes);
1328 INIT_LIST_HEAD(&tp->list);
fc9d276f 1329 list_add(&tp->list, &tp->event->probes);
d59fae6f 1330
60d53e2c
MH		 1331 call = trace_probe_event_call(tp);
1332 call->class = &tp->event->class;
1333 call->name = kstrdup(event, GFP_KERNEL);
1334 if (!call->name) {
1335 ret = -ENOMEM;
1336 goto error;
1337 }
1338
1339 tp->event->class.system = kstrdup(group, GFP_KERNEL);
1340 if (!tp->event->class.system) {
1341 ret = -ENOMEM;
1342 goto error;
455b2899 1343 }
455b2899
MH		 1344
1345 return 0;
60d53e2c
MH		 1346
1347error:
1348 trace_probe_cleanup(tp);
1349 return ret;
455b2899 1350}
46e5376d 1351
8e242060
MH		 1352static struct trace_event_call *
1353find_trace_event_call(const char *system, const char *event_name)
1354{
1355 struct trace_event_call *tp_event;
1356 const char *name;
1357
1358 list_for_each_entry(tp_event, &ftrace_events, list) {
1359 if (!tp_event->class->system ||
1360 strcmp(system, tp_event->class->system))
1361 continue;
1362 name = trace_event_name(tp_event);
1363 if (!name || strcmp(event_name, name))
1364 continue;
1365 return tp_event;
1366 }
1367
1368 return NULL;
1369}
1370
46e5376d
MH		 1371int trace_probe_register_event_call(struct trace_probe *tp)
1372{
e3dc9f89 1373 struct trace_event_call *call = trace_probe_event_call(tp);
46e5376d
MH		 1374 int ret;
1375
8e242060
MH		 1376 lockdep_assert_held(&event_mutex);
1377
1378 if (find_trace_event_call(trace_probe_group_name(tp),
1379 trace_probe_name(tp)))
1380 return -EEXIST;
1381
46e5376d
MH		 1382 ret = register_trace_event(&call->event);
1383 if (!ret)
1384 return -ENODEV;
1385
1386 ret = trace_add_event_call(call);
1387 if (ret)
1388 unregister_trace_event(&call->event);
1389
1390 return ret;
1391}
b5f935ee
MH		 1392
1393int trace_probe_add_file(struct trace_probe *tp, struct trace_event_file *file)
1394{
1395 struct event_file_link *link;
1396
1397 link = kmalloc(sizeof(*link), GFP_KERNEL);
1398 if (!link)
1399 return -ENOMEM;
1400
1401 link->file = file;
1402 INIT_LIST_HEAD(&link->list);
60d53e2c 1403 list_add_tail_rcu(&link->list, &tp->event->files);
747774d6 1404 trace_probe_set_flag(tp, TP_FLAG_TRACE);
b5f935ee
MH		 1405 return 0;
1406}
1407
1408struct event_file_link *trace_probe_get_file_link(struct trace_probe *tp,
1409 struct trace_event_file *file)
1410{
1411 struct event_file_link *link;
1412
1413 trace_probe_for_each_link(link, tp) {
1414 if (link->file == file)
1415 return link;
1416 }
1417
1418 return NULL;
1419}
1420
1421int trace_probe_remove_file(struct trace_probe *tp,
1422 struct trace_event_file *file)
1423{
1424 struct event_file_link *link;
1425
1426 link = trace_probe_get_file_link(tp, file);
1427 if (!link)
1428 return -ENOENT;
1429
1430 list_del_rcu(&link->list);
cae16f2c 1431 kvfree_rcu_mightsleep(link);
b5f935ee 1432
60d53e2c 1433 if (list_empty(&tp->event->files))
747774d6 1434 trace_probe_clear_flag(tp, TP_FLAG_TRACE);
b5f935ee
MH		 1435
1436 return 0;
1437}
ca89bc07
MH		 1438
1439/*
1440 * Return the smallest index of different type argument (start from 1).
1441 * If all argument types and name are same, return 0.
1442 */
1443int trace_probe_compare_arg_type(struct trace_probe *a, struct trace_probe *b)
1444{
1445 int i;
1446
d2aea95a
MH		 1447 /* In case of more arguments */
1448 if (a->nr_args < b->nr_args)
1449 return a->nr_args + 1;
1450 if (a->nr_args > b->nr_args)
1451 return b->nr_args + 1;
1452
ca89bc07
MH		 1453 for (i = 0; i < a->nr_args; i++) {
1454 if ((b->nr_args <= i) ||
1455 ((a->args[i].type != b->args[i].type) ||
1456 (a->args[i].count != b->args[i].count) ||
1457 strcmp(a->args[i].name, b->args[i].name)))
1458 return i + 1;
1459 }
1460
1461 return 0;
1462}
eb5bf813
MH		 1463
1464bool trace_probe_match_command_args(struct trace_probe *tp,
1465 int argc, const char **argv)
1466{
1467 char buf[MAX_ARGSTR_LEN + 1];
1468 int i;
1469
1470 if (tp->nr_args < argc)
1471 return false;
1472
1473 for (i = 0; i < argc; i++) {
1474 snprintf(buf, sizeof(buf), "%s=%s",
1475 tp->args[i].name, tp->args[i].comm);
1476 if (strcmp(buf, argv[i]))
1477 return false;
1478 }
1479 return true;
1480}
d262271d
MH		 1481
1482int trace_probe_create(const char *raw_command, int (*createfn)(int, const char **))
1483{
1484 int argc = 0, ret = 0;
1485 char **argv;
1486
1487 argv = argv_split(GFP_KERNEL, raw_command, &argc);
1488 if (!argv)
1489 return -ENOMEM;
1490
1491 if (argc)
1492 ret = createfn(argc, (const char **)argv);
1493
1494 argv_free(argv);
1495
1496 return ret;
1497}
196b6389
SC		 1498
1499int trace_probe_print_args(struct trace_seq *s, struct probe_arg *args, int nr_args,
1500 u8 *data, void *field)
1501{
1502 void *p;
1503 int i, j;
1504
1505 for (i = 0; i < nr_args; i++) {
1506 struct probe_arg *a = args + i;
1507
1508 trace_seq_printf(s, " %s=", a->name);
1509 if (likely(!a->count)) {
1510 if (!a->type->print(s, data + a->offset, field))
1511 return -ENOMEM;
1512 continue;
1513 }
1514 trace_seq_putc(s, '{');
1515 p = data + a->offset;
1516 for (j = 0; j < a->count; j++) {
1517 if (!a->type->print(s, p, field))
1518 return -ENOMEM;
1519 trace_seq_putc(s, j == a->count - 1 ? '}' : ',');
1520 p += a->type->size;
1521 }
1522 }
1523 return 0;
1524}
Linux 6.x block layer and io_uring tree(s)