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Merge tag 'x86-core-2023-08-30-v2' of git://git.kernel.org/pub/scm/linux/kernel/git...
[linux-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)
4ed8f337 70 trace_seq_puts(s, FAULT_STRING);
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 258 }
c7dce4c5 259 strscpy(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
fd26290e 374static const struct btf_type *find_btf_func_proto(const char *funcname)
b576e097
MHG		 375{
376 struct btf *btf = traceprobe_get_btf();
377 const struct btf_type *t;
378 s32 id;
379
fd26290e 380 if (!btf || !funcname)
b576e097
MHG		 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);
1f9f4f47 389 if (!t || !btf_type_is_func(t))
b576e097
MHG		 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);
1f9f4f47 394 if (!t || !btf_type_is_func_proto(t))
b576e097
MHG		 395 return ERR_PTR(-ENOENT);
396
fd26290e
MHG		 397 return t;
398}
399
400static const struct btf_param *find_btf_func_param(const char *funcname, s32 *nr,
401 bool tracepoint)
402{
403 const struct btf_param *param;
404 const struct btf_type *t;
405
406 if (!funcname || !nr)
407 return ERR_PTR(-EINVAL);
408
409 t = find_btf_func_proto(funcname);
410 if (IS_ERR(t))
411 return (const struct btf_param *)t;
412
b576e097 413 *nr = btf_type_vlen(t);
18b1e870 414 param = (const struct btf_param *)(t + 1);
b576e097 415
18b1e870
MHG		 416 /* Hide the first 'data' argument of tracepoint */
417 if (tracepoint) {
418 (*nr)--;
419 param++;
420 }
421
422 if (*nr > 0)
423 return param;
b576e097
MHG		 424 else
425 return NULL;
426}
427
428static int parse_btf_arg(const char *varname, struct fetch_insn *code,
429 struct traceprobe_parse_context *ctx)
430{
431 struct btf *btf = traceprobe_get_btf();
432 const struct btf_param *params;
433 int i;
434
435 if (!btf) {
436 trace_probe_log_err(ctx->offset, NOSUP_BTFARG);
437 return -EOPNOTSUPP;
438 }
439
440 if (WARN_ON_ONCE(!ctx->funcname))
441 return -EINVAL;
442
443 if (!ctx->params) {
18b1e870
MHG		 444 params = find_btf_func_param(ctx->funcname, &ctx->nr_params,
445 ctx->flags & TPARG_FL_TPOINT);
1f9f4f47 446 if (IS_ERR_OR_NULL(params)) {
b576e097
MHG		 447 trace_probe_log_err(ctx->offset, NO_BTF_ENTRY);
448 return PTR_ERR(params);
449 }
450 ctx->params = params;
451 } else
452 params = ctx->params;
453
454 for (i = 0; i < ctx->nr_params; i++) {
455 const char *name = btf_name_by_offset(btf, params[i].name_off);
456
457 if (name && !strcmp(name, varname)) {
458 code->op = FETCH_OP_ARG;
53431798
MHG		 459 if (ctx->flags & TPARG_FL_TPOINT)
460 code->param = i + 1;
461 else
462 code->param = i;
b576e097
MHG		 463 return 0;
464 }
465 }
466 trace_probe_log_err(ctx->offset, NO_BTFARG);
467 return -ENOENT;
468}
469
470static const struct fetch_type *parse_btf_arg_type(int arg_idx,
471 struct traceprobe_parse_context *ctx)
472{
473 struct btf *btf = traceprobe_get_btf();
474 const char *typestr = NULL;
475
53431798
MHG		 476 if (btf && ctx->params) {
477 if (ctx->flags & TPARG_FL_TPOINT)
478 arg_idx--;
b576e097 479 typestr = type_from_btf_id(btf, ctx->params[arg_idx].type);
53431798 480 }
b576e097
MHG		 481
482 return find_fetch_type(typestr, ctx->flags);
483}
18b1e870 484
fd26290e
MHG		 485static const struct fetch_type *parse_btf_retval_type(
486 struct traceprobe_parse_context *ctx)
487{
488 struct btf *btf = traceprobe_get_btf();
489 const char *typestr = NULL;
490 const struct btf_type *t;
491
492 if (btf && ctx->funcname) {
493 t = find_btf_func_proto(ctx->funcname);
494 if (!IS_ERR(t))
495 typestr = type_from_btf_id(btf, t->type);
496 }
497
498 return find_fetch_type(typestr, ctx->flags);
499}
500
501static bool is_btf_retval_void(const char *funcname)
502{
503 const struct btf_type *t;
504
505 t = find_btf_func_proto(funcname);
506 if (IS_ERR(t))
507 return false;
508
509 return t->type == 0;
510}
b576e097
MHG		 511#else
512static struct btf *traceprobe_get_btf(void)
513{
514 return NULL;
515}
516
18b1e870
MHG		 517static const struct btf_param *find_btf_func_param(const char *funcname, s32 *nr,
518 bool tracepoint)
519{
520 return ERR_PTR(-EOPNOTSUPP);
521}
522
b576e097
MHG		 523static int parse_btf_arg(const char *varname, struct fetch_insn *code,
524 struct traceprobe_parse_context *ctx)
525{
526 trace_probe_log_err(ctx->offset, NOSUP_BTFARG);
527 return -EOPNOTSUPP;
528}
fd26290e 529
b576e097
MHG		 530#define parse_btf_arg_type(idx, ctx) \
531 find_fetch_type(NULL, ctx->flags)
fd26290e
MHG		 532
533#define parse_btf_retval_type(ctx) \
534 find_fetch_type(NULL, ctx->flags)
535
536#define is_btf_retval_void(funcname) (false)
537
b576e097
MHG		 538#endif
539
8ab83f56
SD		 540#define PARAM_MAX_STACK (THREAD_SIZE / sizeof(unsigned long))
541
542static int parse_probe_vars(char *arg, const struct fetch_type *t,
1b8b0cd7
MHG		 543 struct fetch_insn *code,
544 struct traceprobe_parse_context *ctx)
8ab83f56 545{
8ab83f56 546 unsigned long param;
1b8b0cd7 547 int err = TP_ERR_BAD_VAR;
3d739c1f
SRV		 548 int ret = 0;
549 int len;
8ab83f56 550
1b8b0cd7 551 if (ctx->flags & TPARG_FL_TEVENT) {
2673c60e
SRG		 552 if (code->data)
553 return -EFAULT;
1b8b0cd7
MHG		 554 ret = parse_trace_event_arg(arg, code, ctx);
555 if (!ret)
556 return 0;
557 if (strcmp(arg, "comm") == 0 || strcmp(arg, "COMM") == 0) {
558 code->op = FETCH_OP_COMM;
559 return 0;
560 }
561 /* backward compatibility */
562 ctx->offset = 0;
563 goto inval;
564 }
565
566 if (strcmp(arg, "retval") == 0) {
567 if (ctx->flags & TPARG_FL_RETURN) {
fd26290e
MHG		 568 if ((ctx->flags & TPARG_FL_KERNEL) &&
569 is_btf_retval_void(ctx->funcname)) {
570 err = TP_ERR_NO_RETVAL;
571 goto inval;
572 }
53305928 573 code->op = FETCH_OP_RETVAL;
1b8b0cd7 574 return 0;
ab105a4f 575 }
1b8b0cd7
MHG		 576 err = TP_ERR_RETVAL_ON_PROBE;
577 goto inval;
578 }
579
580 len = str_has_prefix(arg, "stack");
581 if (len) {
582
3d739c1f 583 if (arg[len] == '\0') {
53305928 584 code->op = FETCH_OP_STACKP;
1b8b0cd7
MHG		 585 return 0;
586 }
587
588 if (isdigit(arg[len])) {
3d739c1f 589 ret = kstrtoul(arg + len, 10, &param);
1b8b0cd7
MHG		 590 if (ret)
591 goto inval;
592
593 if ((ctx->flags & TPARG_FL_KERNEL) &&
594 param > PARAM_MAX_STACK) {
595 err = TP_ERR_BAD_STACK_NUM;
596 goto inval;
8ab83f56 597 }
1b8b0cd7
MHG		 598 code->op = FETCH_OP_STACK;
599 code->param = (unsigned int)param;
600 return 0;
601 }
602 goto inval;
603 }
604
605 if (strcmp(arg, "comm") == 0 || strcmp(arg, "COMM") == 0) {
53305928 606 code->op = FETCH_OP_COMM;
1b8b0cd7
MHG		 607 return 0;
608 }
609
a1303af5 610#ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API
1b8b0cd7
MHG		 611 len = str_has_prefix(arg, "arg");
612 if (len && tparg_is_function_entry(ctx->flags)) {
3d739c1f 613 ret = kstrtoul(arg + len, 10, &param);
1b8b0cd7
MHG		 614 if (ret)
615 goto inval;
616
617 if (!param || param > PARAM_MAX_STACK) {
618 err = TP_ERR_BAD_ARG_NUM;
619 goto inval;
ab105a4f 620 }
1b8b0cd7 621
a1303af5
MH		 622 code->op = FETCH_OP_ARG;
623 code->param = (unsigned int)param - 1;
e2d0d7b2
MHG		 624 /*
625 * The tracepoint probe will probe a stub function, and the
626 * first parameter of the stub is a dummy and should be ignored.
627 */
1b8b0cd7 628 if (ctx->flags & TPARG_FL_TPOINT)
e2d0d7b2 629 code->param++;
1b8b0cd7
MHG		 630 return 0;
631 }
a1303af5 632#endif
ab105a4f 633
1b8b0cd7
MHG		 634inval:
635 __trace_probe_log_err(ctx->offset, err);
ab105a4f 636 return -EINVAL;
8ab83f56
SD		 637}
638
6218bf9f
MH		 639static int str_to_immediate(char *str, unsigned long *imm)
640{
641 if (isdigit(str[0]))
642 return kstrtoul(str, 0, imm);
643 else if (str[0] == '-')
644 return kstrtol(str, 0, (long *)imm);
645 else if (str[0] == '+')
646 return kstrtol(str + 1, 0, (long *)imm);
647 return -EINVAL;
648}
649
a42e3c4d
MH		 650static int __parse_imm_string(char *str, char **pbuf, int offs)
651{
652 size_t len = strlen(str);
653
654 if (str[len - 1] != '"') {
655 trace_probe_log_err(offs + len, IMMSTR_NO_CLOSE);
656 return -EINVAL;
657 }
658 *pbuf = kstrndup(str, len - 1, GFP_KERNEL);
1c1857d4
XW		 659 if (!*pbuf)
660 return -ENOMEM;
a42e3c4d
MH		 661 return 0;
662}
663
8ab83f56 664/* Recursive argument parser */
53305928
MH		 665static int
666parse_probe_arg(char *arg, const struct fetch_type *type,
667 struct fetch_insn **pcode, struct fetch_insn *end,
1b8b0cd7 668 struct traceprobe_parse_context *ctx)
8ab83f56 669{
53305928 670 struct fetch_insn *code = *pcode;
8ab83f56 671 unsigned long param;
e65f7ae7 672 int deref = FETCH_OP_DEREF;
bf173ca9 673 long offset = 0;
8ab83f56 674 char *tmp;
34fee3a1 675 int ret = 0;
8ab83f56 676
8ab83f56
SD		 677 switch (arg[0]) {
678 case '$':
1b8b0cd7 679 ret = parse_probe_vars(arg + 1, type, code, ctx);
8ab83f56
SD		 680 break;
681
682 case '%': /* named register */
1b8b0cd7 683 if (ctx->flags & (TPARG_FL_TEVENT | TPARG_FL_FPROBE)) {
334e5519 684 /* eprobe and fprobe do not handle registers */
1b8b0cd7 685 trace_probe_log_err(ctx->offset, BAD_VAR);
2673c60e
SRG		 686 break;
687 }
8ab83f56
SD		 688 ret = regs_query_register_offset(arg + 1);
689 if (ret >= 0) {
53305928
MH		 690 code->op = FETCH_OP_REG;
691 code->param = (unsigned int)ret;
8ab83f56 692 ret = 0;
ab105a4f 693 } else
1b8b0cd7 694 trace_probe_log_err(ctx->offset, BAD_REG_NAME);
8ab83f56
SD		 695 break;
696
b7e0bf34 697 case '@': /* memory, file-offset or symbol */
8ab83f56 698 if (isdigit(arg[1])) {
bcd83ea6 699 ret = kstrtoul(arg + 1, 0, &param);
ab105a4f 700 if (ret) {
1b8b0cd7 701 trace_probe_log_err(ctx->offset, BAD_MEM_ADDR);
8ab83f56 702 break;
ab105a4f 703 }
53305928
MH		 704 /* load address */
705 code->op = FETCH_OP_IMM;
706 code->immediate = param;
b7e0bf34
NK		 707 } else if (arg[1] == '+') {
708 /* kprobes don't support file offsets */
1b8b0cd7
MHG		 709 if (ctx->flags & TPARG_FL_KERNEL) {
710 trace_probe_log_err(ctx->offset, FILE_ON_KPROBE);
b7e0bf34 711 return -EINVAL;
ab105a4f 712 }
b7e0bf34 713 ret = kstrtol(arg + 2, 0, &offset);
ab105a4f 714 if (ret) {
1b8b0cd7 715 trace_probe_log_err(ctx->offset, BAD_FILE_OFFS);
b7e0bf34 716 break;
ab105a4f 717 }
b7e0bf34 718
53305928
MH		 719 code->op = FETCH_OP_FOFFS;
720 code->immediate = (unsigned long)offset; // imm64?
8ab83f56 721 } else {
b079d374 722 /* uprobes don't support symbols */
1b8b0cd7
MHG		 723 if (!(ctx->flags & TPARG_FL_KERNEL)) {
724 trace_probe_log_err(ctx->offset, SYM_ON_UPROBE);
b079d374 725 return -EINVAL;
ab105a4f 726 }
a6682814
MH		 727 /* Preserve symbol for updating */
728 code->op = FETCH_NOP_SYMBOL;
729 code->data = kstrdup(arg + 1, GFP_KERNEL);
730 if (!code->data)
731 return -ENOMEM;
ab105a4f 732 if (++code == end) {
1b8b0cd7 733 trace_probe_log_err(ctx->offset, TOO_MANY_OPS);
ab105a4f
MH		 734 return -EINVAL;
735 }
53305928 736 code->op = FETCH_OP_IMM;
a6682814 737 code->immediate = 0;
8ab83f56 738 }
53305928 739 /* These are fetching from memory */
ab105a4f 740 if (++code == end) {
1b8b0cd7 741 trace_probe_log_err(ctx->offset, TOO_MANY_OPS);
ab105a4f
MH		 742 return -EINVAL;
743 }
53305928
MH		 744 *pcode = code;
745 code->op = FETCH_OP_DEREF;
746 code->offset = offset;
8ab83f56
SD		 747 break;
748
749 case '+': /* deref memory */
8ab83f56 750 case '-':
e65f7ae7
MH		 751 if (arg[1] == 'u') {
752 deref = FETCH_OP_UDEREF;
753 arg[1] = arg[0];
754 arg++;
755 }
756 if (arg[0] == '+')
757 arg++; /* Skip '+', because kstrtol() rejects it. */
8ab83f56 758 tmp = strchr(arg, '(');
ab105a4f 759 if (!tmp) {
1b8b0cd7 760 trace_probe_log_err(ctx->offset, DEREF_NEED_BRACE);
53305928 761 return -EINVAL;
ab105a4f 762 }
8ab83f56 763 *tmp = '\0';
bcd83ea6 764 ret = kstrtol(arg, 0, &offset);
ab105a4f 765 if (ret) {
1b8b0cd7 766 trace_probe_log_err(ctx->offset, BAD_DEREF_OFFS);
8ab83f56 767 break;
ab105a4f 768 }
1b8b0cd7 769 ctx->offset += (tmp + 1 - arg) + (arg[0] != '-' ? 1 : 0);
8ab83f56
SD		 770 arg = tmp + 1;
771 tmp = strrchr(arg, ')');
ab105a4f 772 if (!tmp) {
1b8b0cd7 773 trace_probe_log_err(ctx->offset + strlen(arg),
ab105a4f
MH		 774 DEREF_OPEN_BRACE);
775 return -EINVAL;
776 } else {
1b8b0cd7
MHG		 777 const struct fetch_type *t2 = find_fetch_type(NULL, ctx->flags);
778 int cur_offs = ctx->offset;
8ab83f56 779
8ab83f56 780 *tmp = '\0';
1b8b0cd7 781 ret = parse_probe_arg(arg, t2, &code, end, ctx);
8ab83f56 782 if (ret)
53305928 783 break;
1b8b0cd7 784 ctx->offset = cur_offs;
a42e3c4d
MH		 785 if (code->op == FETCH_OP_COMM ||
786 code->op == FETCH_OP_DATA) {
1b8b0cd7 787 trace_probe_log_err(ctx->offset, COMM_CANT_DEREF);
ab105a4f
MH		 788 return -EINVAL;
789 }
790 if (++code == end) {
1b8b0cd7 791 trace_probe_log_err(ctx->offset, TOO_MANY_OPS);
53305928 792 return -EINVAL;
ab105a4f 793 }
53305928
MH		 794 *pcode = code;
795
e65f7ae7 796 code->op = deref;
53305928 797 code->offset = offset;
8ab83f56
SD		 798 }
799 break;
6218bf9f 800 case '\\': /* Immediate value */
a42e3c4d 801 if (arg[1] == '"') { /* Immediate string */
1b8b0cd7 802 ret = __parse_imm_string(arg + 2, &tmp, ctx->offset + 2);
a42e3c4d
MH		 803 if (ret)
804 break;
805 code->op = FETCH_OP_DATA;
806 code->data = tmp;
807 } else {
808 ret = str_to_immediate(arg + 1, &code->immediate);
809 if (ret)
1b8b0cd7 810 trace_probe_log_err(ctx->offset + 1, BAD_IMM);
a42e3c4d
MH		 811 else
812 code->op = FETCH_OP_IMM;
813 }
6218bf9f 814 break;
b576e097
MHG		 815 default:
816 if (isalpha(arg[0]) || arg[0] == '_') { /* BTF variable */
817 if (!tparg_is_function_entry(ctx->flags)) {
818 trace_probe_log_err(ctx->offset, NOSUP_BTFARG);
819 return -EINVAL;
820 }
821 ret = parse_btf_arg(arg, code, ctx);
822 break;
823 }
8ab83f56 824 }
53305928
MH		 825 if (!ret && code->op == FETCH_OP_NOP) {
826 /* Parsed, but do not find fetch method */
1b8b0cd7 827 trace_probe_log_err(ctx->offset, BAD_FETCH_ARG);
8ab83f56
SD		 828 ret = -EINVAL;
829 }
8ab83f56
SD		 830 return ret;
831}
832
833#define BYTES_TO_BITS(nb) ((BITS_PER_LONG * (nb)) / sizeof(long))
834
835/* Bitfield type needs to be parsed into a fetch function */
836static int __parse_bitfield_probe_arg(const char *bf,
837 const struct fetch_type *t,
53305928 838 struct fetch_insn **pcode)
8ab83f56 839{
53305928 840 struct fetch_insn *code = *pcode;
8ab83f56
SD		 841 unsigned long bw, bo;
842 char *tail;
843
844 if (*bf != 'b')
845 return 0;
846
8ab83f56
SD		 847 bw = simple_strtoul(bf + 1, &tail, 0); /* Use simple one */
848
849 if (bw == 0 || *tail != '@')
850 return -EINVAL;
851
852 bf = tail + 1;
853 bo = simple_strtoul(bf, &tail, 0);
854
855 if (tail == bf || *tail != '/')
856 return -EINVAL;
53305928
MH		 857 code++;
858 if (code->op != FETCH_OP_NOP)
ab105a4f 859 return -EINVAL;
53305928 860 *pcode = code;
8ab83f56 861
53305928
MH		 862 code->op = FETCH_OP_MOD_BF;
863 code->lshift = BYTES_TO_BITS(t->size) - (bw + bo);
864 code->rshift = BYTES_TO_BITS(t->size) - bw;
865 code->basesize = t->size;
8ab83f56
SD		 866
867 return (BYTES_TO_BITS(t->size) < (bw + bo)) ? -EINVAL : 0;
868}
869
870/* String length checking wrapper */
fcd9db51 871static int traceprobe_parse_probe_arg_body(const char *argv, ssize_t *size,
1b8b0cd7
MHG		 872 struct probe_arg *parg,
873 struct traceprobe_parse_context *ctx)
8ab83f56 874{
40b53b77 875 struct fetch_insn *code, *scode, *tmp = NULL;
ab105a4f 876 char *t, *t2, *t3;
40b53b77 877 int ret, len;
1b8b0cd7 878 char *arg;
8ab83f56 879
fcd9db51
SRV		 880 arg = kstrdup(argv, GFP_KERNEL);
881 if (!arg)
882 return -ENOMEM;
883
884 ret = -EINVAL;
ab105a4f
MH		 885 len = strlen(arg);
886 if (len > MAX_ARGSTR_LEN) {
1b8b0cd7 887 trace_probe_log_err(ctx->offset, ARG_TOO_LONG);
fcd9db51 888 goto out;
ab105a4f 889 } else if (len == 0) {
1b8b0cd7 890 trace_probe_log_err(ctx->offset, NO_ARG_BODY);
fcd9db51 891 goto out;
8ab83f56 892 }
ab105a4f 893
fcd9db51 894 ret = -ENOMEM;
8ab83f56 895 parg->comm = kstrdup(arg, GFP_KERNEL);
ab105a4f 896 if (!parg->comm)
fcd9db51 897 goto out;
ab105a4f 898
fcd9db51 899 ret = -EINVAL;
40b53b77 900 t = strchr(arg, ':');
8ab83f56 901 if (t) {
40b53b77
MH		 902 *t = '\0';
903 t2 = strchr(++t, '[');
904 if (t2) {
ab105a4f
MH		 905 *t2++ = '\0';
906 t3 = strchr(t2, ']');
907 if (!t3) {
1b8b0cd7
MHG		 908 int offs = t2 + strlen(t2) - arg;
909
910 trace_probe_log_err(ctx->offset + offs,
ab105a4f 911 ARRAY_NO_CLOSE);
fcd9db51 912 goto out;
ab105a4f 913 } else if (t3[1] != '\0') {
1b8b0cd7 914 trace_probe_log_err(ctx->offset + t3 + 1 - arg,
ab105a4f 915 BAD_ARRAY_SUFFIX);
fcd9db51 916 goto out;
ab105a4f
MH		 917 }
918 *t3 = '\0';
919 if (kstrtouint(t2, 0, &parg->count) || !parg->count) {
1b8b0cd7 920 trace_probe_log_err(ctx->offset + t2 - arg,
ab105a4f 921 BAD_ARRAY_NUM);
fcd9db51 922 goto out;
ab105a4f
MH		 923 }
924 if (parg->count > MAX_ARRAY_LEN) {
1b8b0cd7 925 trace_probe_log_err(ctx->offset + t2 - arg,
ab105a4f 926 ARRAY_TOO_BIG);
fcd9db51 927 goto out;
ab105a4f 928 }
40b53b77 929 }
8ab83f56 930 }
3dd1f7f2 931
a42e3c4d 932 /*
f2cc020d 933 * Since $comm and immediate string can not be dereferenced,
02333de9 934 * we can find those by strcmp. But ignore for eprobes.
a42e3c4d 935 */
1b8b0cd7 936 if (!(ctx->flags & TPARG_FL_TEVENT) &&
ab838444
SRG		 937 (strcmp(arg, "$comm") == 0 || strcmp(arg, "$COMM") == 0 ||
938 strncmp(arg, "\\\"", 2) == 0)) {
3dd1f7f2
MH		 939 /* The type of $comm must be "string", and not an array. */
940 if (parg->count || (t && strcmp(t, "string")))
fcd9db51 941 goto out;
1b8b0cd7 942 parg->type = find_fetch_type("string", ctx->flags);
3dd1f7f2 943 } else
1b8b0cd7 944 parg->type = find_fetch_type(t, ctx->flags);
8ab83f56 945 if (!parg->type) {
1b8b0cd7 946 trace_probe_log_err(ctx->offset + (t ? (t - arg) : 0), BAD_TYPE);
fcd9db51 947 goto out;
8ab83f56
SD		 948 }
949 parg->offset = *size;
40b53b77
MH		 950 *size += parg->type->size * (parg->count ?: 1);
951
fcd9db51 952 ret = -ENOMEM;
40b53b77
MH		 953 if (parg->count) {
954 len = strlen(parg->type->fmttype) + 6;
955 parg->fmt = kmalloc(len, GFP_KERNEL);
956 if (!parg->fmt)
fcd9db51 957 goto out;
40b53b77
MH		 958 snprintf(parg->fmt, len, "%s[%d]", parg->type->fmttype,
959 parg->count);
960 }
8ab83f56 961
8623b006 962 code = tmp = kcalloc(FETCH_INSN_MAX, sizeof(*code), GFP_KERNEL);
53305928 963 if (!code)
fcd9db51 964 goto out;
53305928
MH		 965 code[FETCH_INSN_MAX - 1].op = FETCH_OP_END;
966
967 ret = parse_probe_arg(arg, parg->type, &code, &code[FETCH_INSN_MAX - 1],
1b8b0cd7 968 ctx);
53305928
MH		 969 if (ret)
970 goto fail;
971
b576e097 972 /* Update storing type if BTF is available */
fd26290e
MHG		 973 if (IS_ENABLED(CONFIG_PROBE_EVENTS_BTF_ARGS) && !t) {
974 if (code->op == FETCH_OP_ARG)
975 parg->type = parse_btf_arg_type(code->param, ctx);
976 else if (code->op == FETCH_OP_RETVAL)
977 parg->type = parse_btf_retval_type(ctx);
978 }
b576e097 979
fcd9db51 980 ret = -EINVAL;
53305928 981 /* Store operation */
b26a124c
MHG		 982 if (parg->type->is_string) {
983 if (!strcmp(parg->type->name, "symstr")) {
984 if (code->op != FETCH_OP_REG && code->op != FETCH_OP_STACK &&
985 code->op != FETCH_OP_RETVAL && code->op != FETCH_OP_ARG &&
986 code->op != FETCH_OP_DEREF && code->op != FETCH_OP_TP_ARG) {
1b8b0cd7 987 trace_probe_log_err(ctx->offset + (t ? (t - arg) : 0),
b26a124c
MHG		 988 BAD_SYMSTRING);
989 goto fail;
990 }
991 } else {
992 if (code->op != FETCH_OP_DEREF && code->op != FETCH_OP_UDEREF &&
993 code->op != FETCH_OP_IMM && code->op != FETCH_OP_COMM &&
994 code->op != FETCH_OP_DATA && code->op != FETCH_OP_TP_ARG) {
1b8b0cd7 995 trace_probe_log_err(ctx->offset + (t ? (t - arg) : 0),
b26a124c
MHG		 996 BAD_STRING);
997 goto fail;
998 }
53305928 999 }
b26a124c
MHG		 1000 if (!strcmp(parg->type->name, "symstr") ||
1001 (code->op == FETCH_OP_IMM || code->op == FETCH_OP_COMM ||
7491e2c4
TSV		 1002 code->op == FETCH_OP_DATA) || code->op == FETCH_OP_TP_ARG ||
1003 parg->count) {
40b53b77 1004 /*
a42e3c4d
MH		 1005 * IMM, DATA and COMM is pointing actual address, those
1006 * must be kept, and if parg->count != 0, this is an
1007 * array of string pointers instead of string address
1008 * itself.
b26a124c
MHG		 1009 * For the symstr, it doesn't need to dereference, thus
1010 * it just get the value.
40b53b77 1011 */
53305928 1012 code++;
40b53b77 1013 if (code->op != FETCH_OP_NOP) {
1b8b0cd7 1014 trace_probe_log_err(ctx->offset, TOO_MANY_OPS);
40b53b77
MH		 1015 goto fail;
1016 }
1017 }
88903c46 1018 /* If op == DEREF, replace it with STRING */
e65f7ae7
MH		 1019 if (!strcmp(parg->type->name, "ustring") ||
1020 code->op == FETCH_OP_UDEREF)
88903c46 1021 code->op = FETCH_OP_ST_USTRING;
b26a124c
MHG		 1022 else if (!strcmp(parg->type->name, "symstr"))
1023 code->op = FETCH_OP_ST_SYMSTR;
88903c46
MH		 1024 else
1025 code->op = FETCH_OP_ST_STRING;
40b53b77 1026 code->size = parg->type->size;
53305928
MH		 1027 parg->dynamic = true;
1028 } else if (code->op == FETCH_OP_DEREF) {
1029 code->op = FETCH_OP_ST_MEM;
1030 code->size = parg->type->size;
e65f7ae7
MH		 1031 } else if (code->op == FETCH_OP_UDEREF) {
1032 code->op = FETCH_OP_ST_UMEM;
1033 code->size = parg->type->size;
53305928
MH		 1034 } else {
1035 code++;
1036 if (code->op != FETCH_OP_NOP) {
1b8b0cd7 1037 trace_probe_log_err(ctx->offset, TOO_MANY_OPS);
53305928
MH		 1038 goto fail;
1039 }
1040 code->op = FETCH_OP_ST_RAW;
1041 code->size = parg->type->size;
1042 }
40b53b77 1043 scode = code;
53305928
MH		 1044 /* Modify operation */
1045 if (t != NULL) {
1046 ret = __parse_bitfield_probe_arg(t, parg->type, &code);
ab105a4f 1047 if (ret) {
1b8b0cd7 1048 trace_probe_log_err(ctx->offset + t - arg, BAD_BITFIELD);
53305928 1049 goto fail;
ab105a4f 1050 }
8ab83f56 1051 }
fcd9db51 1052 ret = -EINVAL;
40b53b77
MH		 1053 /* Loop(Array) operation */
1054 if (parg->count) {
1055 if (scode->op != FETCH_OP_ST_MEM &&
88903c46
MH		 1056 scode->op != FETCH_OP_ST_STRING &&
1057 scode->op != FETCH_OP_ST_USTRING) {
1b8b0cd7 1058 trace_probe_log_err(ctx->offset + (t ? (t - arg) : 0),
ab105a4f 1059 BAD_STRING);
40b53b77
MH		 1060 goto fail;
1061 }
1062 code++;
1063 if (code->op != FETCH_OP_NOP) {
1b8b0cd7 1064 trace_probe_log_err(ctx->offset, TOO_MANY_OPS);
40b53b77
MH		 1065 goto fail;
1066 }
1067 code->op = FETCH_OP_LP_ARRAY;
1068 code->param = parg->count;
1069 }
53305928
MH		 1070 code++;
1071 code->op = FETCH_OP_END;
1072
fcd9db51 1073 ret = 0;
53305928 1074 /* Shrink down the code buffer */
8623b006 1075 parg->code = kcalloc(code - tmp + 1, sizeof(*code), GFP_KERNEL);
53305928
MH		 1076 if (!parg->code)
1077 ret = -ENOMEM;
1078 else
1079 memcpy(parg->code, tmp, sizeof(*code) * (code - tmp + 1));
1080
1081fail:
a6682814
MH		 1082 if (ret) {
1083 for (code = tmp; code < tmp + FETCH_INSN_MAX; code++)
a42e3c4d
MH		 1084 if (code->op == FETCH_NOP_SYMBOL ||
1085 code->op == FETCH_OP_DATA)
a6682814
MH		 1086 kfree(code->data);
1087 }
53305928 1088 kfree(tmp);
fcd9db51
SRV		 1089out:
1090 kfree(arg);
8ab83f56
SD		 1091
1092 return ret;
1093}
1094
1095/* Return 1 if name is reserved or already used by another argument */
d00bbea9
MH		 1096static int traceprobe_conflict_field_name(const char *name,
1097 struct probe_arg *args, int narg)
8ab83f56
SD		 1098{
1099 int i;
1100
1101 for (i = 0; i < ARRAY_SIZE(reserved_field_names); i++)
1102 if (strcmp(reserved_field_names[i], name) == 0)
1103 return 1;
1104
1105 for (i = 0; i < narg; i++)
1106 if (strcmp(args[i].name, name) == 0)
1107 return 1;
1108
1109 return 0;
1110}
1111
b576e097
MHG		 1112static char *generate_probe_arg_name(const char *arg, int idx)
1113{
1114 char *name = NULL;
1115 const char *end;
1116
1117 /*
1118 * If argument name is omitted, try arg as a name (BTF variable)
1119 * or "argN".
1120 */
1121 if (IS_ENABLED(CONFIG_PROBE_EVENTS_BTF_ARGS)) {
1122 end = strchr(arg, ':');
1123 if (!end)
1124 end = arg + strlen(arg);
1125
1126 name = kmemdup_nul(arg, end - arg, GFP_KERNEL);
1127 if (!name || !is_good_name(name)) {
1128 kfree(name);
1129 name = NULL;
1130 }
1131 }
1132
1133 if (!name)
1134 name = kasprintf(GFP_KERNEL, "arg%d", idx + 1);
1135
1136 return name;
1137}
1138
fcd9db51 1139int traceprobe_parse_probe_arg(struct trace_probe *tp, int i, const char *arg,
1b8b0cd7 1140 struct traceprobe_parse_context *ctx)
d00bbea9
MH		 1141{
1142 struct probe_arg *parg = &tp->args[i];
fcd9db51 1143 const char *body;
d00bbea9
MH		 1144
1145 /* Increment count for freeing args in error case */
1146 tp->nr_args++;
1147
1148 body = strchr(arg, '=');
1149 if (body) {
ab105a4f
MH		 1150 if (body - arg > MAX_ARG_NAME_LEN) {
1151 trace_probe_log_err(0, ARG_NAME_TOO_LONG);
1152 return -EINVAL;
1153 } else if (body == arg) {
1154 trace_probe_log_err(0, NO_ARG_NAME);
b4443c17 1155 return -EINVAL;
ab105a4f 1156 }
d00bbea9
MH		 1157 parg->name = kmemdup_nul(arg, body - arg, GFP_KERNEL);
1158 body++;
1159 } else {
b576e097 1160 parg->name = generate_probe_arg_name(arg, i);
d00bbea9
MH		 1161 body = arg;
1162 }
1163 if (!parg->name)
1164 return -ENOMEM;
1165
1166 if (!is_good_name(parg->name)) {
ab105a4f 1167 trace_probe_log_err(0, BAD_ARG_NAME);
d00bbea9
MH		 1168 return -EINVAL;
1169 }
d00bbea9 1170 if (traceprobe_conflict_field_name(parg->name, tp->args, i)) {
ab105a4f 1171 trace_probe_log_err(0, USED_ARG_NAME);
d00bbea9
MH		 1172 return -EINVAL;
1173 }
1b8b0cd7 1174 ctx->offset = body - arg;
d00bbea9 1175 /* Parse fetch argument */
1b8b0cd7 1176 return traceprobe_parse_probe_arg_body(body, &tp->size, parg, ctx);
d00bbea9
MH		 1177}
1178
8ab83f56
SD		 1179void traceprobe_free_probe_arg(struct probe_arg *arg)
1180{
a6682814
MH		 1181 struct fetch_insn *code = arg->code;
1182
1183 while (code && code->op != FETCH_OP_END) {
a42e3c4d
MH		 1184 if (code->op == FETCH_NOP_SYMBOL ||
1185 code->op == FETCH_OP_DATA)
a6682814
MH		 1186 kfree(code->data);
1187 code++;
1188 }
53305928 1189 kfree(arg->code);
8ab83f56
SD		 1190 kfree(arg->name);
1191 kfree(arg->comm);
40b53b77 1192 kfree(arg->fmt);
8ab83f56
SD		 1193}
1194
18b1e870
MHG		 1195static int argv_has_var_arg(int argc, const char *argv[], int *args_idx,
1196 struct traceprobe_parse_context *ctx)
1197{
1198 int i, found = 0;
1199
1200 for (i = 0; i < argc; i++)
1201 if (str_has_prefix(argv[i], "$arg")) {
1202 trace_probe_log_set_index(i + 2);
1203
1204 if (!tparg_is_function_entry(ctx->flags)) {
1205 trace_probe_log_err(0, NOFENTRY_ARGS);
1206 return -EINVAL;
1207 }
1208
1209 if (isdigit(argv[i][4])) {
1210 found = 1;
1211 continue;
1212 }
1213
1214 if (argv[i][4] != '*') {
1215 trace_probe_log_err(0, BAD_VAR);
1216 return -EINVAL;
1217 }
1218
1219 if (*args_idx >= 0 && *args_idx < argc) {
1220 trace_probe_log_err(0, DOUBLE_ARGS);
1221 return -EINVAL;
1222 }
1223 found = 1;
1224 *args_idx = i;
1225 }
1226
1227 return found;
1228}
1229
1230static int sprint_nth_btf_arg(int idx, const char *type,
1231 char *buf, int bufsize,
1232 struct traceprobe_parse_context *ctx)
1233{
1234 struct btf *btf = traceprobe_get_btf();
1235 const char *name;
1236 int ret;
1237
1238 if (idx >= ctx->nr_params) {
1239 trace_probe_log_err(0, NO_BTFARG);
1240 return -ENOENT;
1241 }
1242 name = btf_name_by_offset(btf, ctx->params[idx].name_off);
1243 if (!name) {
1244 trace_probe_log_err(0, NO_BTF_ENTRY);
1245 return -ENOENT;
1246 }
1247 ret = snprintf(buf, bufsize, "%s%s", name, type);
1248 if (ret >= bufsize) {
1249 trace_probe_log_err(0, ARGS_2LONG);
1250 return -E2BIG;
1251 }
1252 return ret;
1253}
1254
1255/* Return new_argv which must be freed after use */
1256const char **traceprobe_expand_meta_args(int argc, const char *argv[],
1257 int *new_argc, char *buf, int bufsize,
1258 struct traceprobe_parse_context *ctx)
1259{
1260 const struct btf_param *params = NULL;
1261 int i, j, n, used, ret, args_idx = -1;
1262 const char **new_argv = NULL;
1263 int nr_params;
1264
1265 ret = argv_has_var_arg(argc, argv, &args_idx, ctx);
1266 if (ret < 0)
1267 return ERR_PTR(ret);
1268
1269 if (!ret) {
1270 *new_argc = argc;
1271 return NULL;
1272 }
1273
1274 params = find_btf_func_param(ctx->funcname, &nr_params,
1275 ctx->flags & TPARG_FL_TPOINT);
1f9f4f47 1276 if (IS_ERR_OR_NULL(params)) {
18b1e870
MHG		 1277 if (args_idx != -1) {
1278 /* $arg* requires BTF info */
1279 trace_probe_log_err(0, NOSUP_BTFARG);
1280 return (const char **)params;
1281 }
ed5f2978
MHG		 1282 *new_argc = argc;
1283 return NULL;
18b1e870
MHG		 1284 }
1285 ctx->params = params;
1286 ctx->nr_params = nr_params;
1287
1288 if (args_idx >= 0)
1289 *new_argc = argc + ctx->nr_params - 1;
1290 else
1291 *new_argc = argc;
1292
1293 new_argv = kcalloc(*new_argc, sizeof(char *), GFP_KERNEL);
1294 if (!new_argv)
1295 return ERR_PTR(-ENOMEM);
1296
1297 used = 0;
1298 for (i = 0, j = 0; i < argc; i++) {
1299 trace_probe_log_set_index(i + 2);
1300 if (i == args_idx) {
1301 for (n = 0; n < nr_params; n++) {
1302 ret = sprint_nth_btf_arg(n, "", buf + used,
1303 bufsize - used, ctx);
1304 if (ret < 0)
1305 goto error;
1306
1307 new_argv[j++] = buf + used;
1308 used += ret + 1;
1309 }
1310 continue;
1311 }
1312
1313 if (str_has_prefix(argv[i], "$arg")) {
1314 char *type = NULL;
1315
1316 n = simple_strtoul(argv[i] + 4, &type, 10);
1317 if (type && !(*type == ':' || *type == '\0')) {
1318 trace_probe_log_err(0, BAD_VAR);
1319 ret = -ENOENT;
1320 goto error;
1321 }
1322 /* Note: $argN starts from $arg1 */
1323 ret = sprint_nth_btf_arg(n - 1, type, buf + used,
1324 bufsize - used, ctx);
1325 if (ret < 0)
1326 goto error;
1327 new_argv[j++] = buf + used;
1328 used += ret + 1;
1329 } else
1330 new_argv[j++] = argv[i];
1331 }
1332
1333 return new_argv;
1334
1335error:
1336 kfree(new_argv);
1337 return ERR_PTR(ret);
1338}
1339
a6682814
MH		 1340int traceprobe_update_arg(struct probe_arg *arg)
1341{
1342 struct fetch_insn *code = arg->code;
1343 long offset;
1344 char *tmp;
1345 char c;
1346 int ret = 0;
1347
1348 while (code && code->op != FETCH_OP_END) {
1349 if (code->op == FETCH_NOP_SYMBOL) {
1350 if (code[1].op != FETCH_OP_IMM)
1351 return -EINVAL;
1352
ee474b81 1353 tmp = strpbrk(code->data, "+-");
a6682814
MH		 1354 if (tmp)
1355 c = *tmp;
1356 ret = traceprobe_split_symbol_offset(code->data,
1357 &offset);
1358 if (ret)
1359 return ret;
1360
1361 code[1].immediate =
1362 (unsigned long)kallsyms_lookup_name(code->data);
1363 if (tmp)
1364 *tmp = c;
1365 if (!code[1].immediate)
1366 return -ENOENT;
1367 code[1].immediate += offset;
1368 }
1369 code++;
1370 }
1371 return 0;
1372}
1373
40b53b77
MH		 1374/* When len=0, we just calculate the needed length */
1375#define LEN_OR_ZERO (len ? len - pos : 0)
5bf652aa 1376static int __set_print_fmt(struct trace_probe *tp, char *buf, int len,
007517a0 1377 enum probe_print_type ptype)
5bf652aa 1378{
40b53b77
MH		 1379 struct probe_arg *parg;
1380 int i, j;
5bf652aa 1381 int pos = 0;
5bf652aa
NK		 1382 const char *fmt, *arg;
1383
007517a0
SRV		 1384 switch (ptype) {
1385 case PROBE_PRINT_NORMAL:
5bf652aa 1386 fmt = "(%lx)";
b61edd57 1387 arg = ", REC->" FIELD_STRING_IP;
007517a0
SRV		 1388 break;
1389 case PROBE_PRINT_RETURN:
5bf652aa 1390 fmt = "(%lx <- %lx)";
b61edd57 1391 arg = ", REC->" FIELD_STRING_FUNC ", REC->" FIELD_STRING_RETIP;
007517a0 1392 break;
7491e2c4 1393 case PROBE_PRINT_EVENT:
b61edd57
SRG		 1394 fmt = "";
1395 arg = "";
7491e2c4 1396 break;
007517a0
SRV		 1397 default:
1398 WARN_ON_ONCE(1);
1399 return 0;
5bf652aa
NK		 1400 }
1401
5bf652aa
NK		 1402 pos += snprintf(buf + pos, LEN_OR_ZERO, "\"%s", fmt);
1403
1404 for (i = 0; i < tp->nr_args; i++) {
40b53b77
MH		 1405 parg = tp->args + i;
1406 pos += snprintf(buf + pos, LEN_OR_ZERO, " %s=", parg->name);
1407 if (parg->count) {
1408 pos += snprintf(buf + pos, LEN_OR_ZERO, "{%s",
1409 parg->type->fmt);
1410 for (j = 1; j < parg->count; j++)
1411 pos += snprintf(buf + pos, LEN_OR_ZERO, ",%s",
1412 parg->type->fmt);
1413 pos += snprintf(buf + pos, LEN_OR_ZERO, "}");
1414 } else
1415 pos += snprintf(buf + pos, LEN_OR_ZERO, "%s",
1416 parg->type->fmt);
5bf652aa
NK		 1417 }
1418
b61edd57 1419 pos += snprintf(buf + pos, LEN_OR_ZERO, "\"%s", arg);
5bf652aa
NK		 1420
1421 for (i = 0; i < tp->nr_args; i++) {
40b53b77
MH		 1422 parg = tp->args + i;
1423 if (parg->count) {
b26a124c 1424 if (parg->type->is_string)
40b53b77
MH		 1425 fmt = ", __get_str(%s[%d])";
1426 else
1427 fmt = ", REC->%s[%d]";
1428 for (j = 0; j < parg->count; j++)
1429 pos += snprintf(buf + pos, LEN_OR_ZERO,
1430 fmt, parg->name, j);
1431 } else {
b26a124c 1432 if (parg->type->is_string)
40b53b77
MH		 1433 fmt = ", __get_str(%s)";
1434 else
1435 fmt = ", REC->%s";
5bf652aa 1436 pos += snprintf(buf + pos, LEN_OR_ZERO,
40b53b77
MH		 1437 fmt, parg->name);
1438 }
5bf652aa
NK		 1439 }
1440
5bf652aa
NK		 1441 /* return the length of print_fmt */
1442 return pos;
1443}
40b53b77 1444#undef LEN_OR_ZERO
5bf652aa 1445
007517a0 1446int traceprobe_set_print_fmt(struct trace_probe *tp, enum probe_print_type ptype)
5bf652aa 1447{
e3dc9f89 1448 struct trace_event_call *call = trace_probe_event_call(tp);
5bf652aa
NK		 1449 int len;
1450 char *print_fmt;
1451
1452 /* First: called with 0 length to calculate the needed length */
007517a0 1453 len = __set_print_fmt(tp, NULL, 0, ptype);
5bf652aa
NK		 1454 print_fmt = kmalloc(len + 1, GFP_KERNEL);
1455 if (!print_fmt)
1456 return -ENOMEM;
1457
1458 /* Second: actually write the @print_fmt */
007517a0 1459 __set_print_fmt(tp, print_fmt, len + 1, ptype);
e3dc9f89 1460 call->print_fmt = print_fmt;
5bf652aa
NK		 1461
1462 return 0;
1463}
eeb07b06
MH		 1464
1465int traceprobe_define_arg_fields(struct trace_event_call *event_call,
1466 size_t offset, struct trace_probe *tp)
1467{
1468 int ret, i;
1469
1470 /* Set argument names as fields */
1471 for (i = 0; i < tp->nr_args; i++) {
1472 struct probe_arg *parg = &tp->args[i];
40b53b77
MH		 1473 const char *fmt = parg->type->fmttype;
1474 int size = parg->type->size;
1475
1476 if (parg->fmt)
1477 fmt = parg->fmt;
1478 if (parg->count)
1479 size *= parg->count;
1480 ret = trace_define_field(event_call, fmt, parg->name,
1481 offset + parg->offset, size,
eeb07b06
MH		 1482 parg->type->is_signed,
1483 FILTER_OTHER);
1484 if (ret)
1485 return ret;
1486 }
1487 return 0;
1488}
455b2899 1489
ca89bc07
MH		 1490static void trace_probe_event_free(struct trace_probe_event *tpe)
1491{
1492 kfree(tpe->class.system);
1493 kfree(tpe->call.name);
1494 kfree(tpe->call.print_fmt);
1495 kfree(tpe);
1496}
1497
1498int trace_probe_append(struct trace_probe *tp, struct trace_probe *to)
1499{
1500 if (trace_probe_has_sibling(tp))
1501 return -EBUSY;
1502
1503 list_del_init(&tp->list);
1504 trace_probe_event_free(tp->event);
1505
1506 tp->event = to->event;
1507 list_add_tail(&tp->list, trace_probe_probe_list(to));
1508
1509 return 0;
1510}
1511
1512void trace_probe_unlink(struct trace_probe *tp)
1513{
1514 list_del_init(&tp->list);
1515 if (list_empty(trace_probe_probe_list(tp)))
1516 trace_probe_event_free(tp->event);
1517 tp->event = NULL;
1518}
455b2899
MH		 1519
1520void trace_probe_cleanup(struct trace_probe *tp)
1521{
1522 int i;
1523
1524 for (i = 0; i < tp->nr_args; i++)
1525 traceprobe_free_probe_arg(&tp->args[i]);
1526
ca89bc07
MH		 1527 if (tp->event)
1528 trace_probe_unlink(tp);
455b2899
MH		 1529}
1530
1531int trace_probe_init(struct trace_probe *tp, const char *event,
b61387cb 1532 const char *group, bool alloc_filter)
455b2899 1533{
60d53e2c 1534 struct trace_event_call *call;
b61387cb 1535 size_t size = sizeof(struct trace_probe_event);
60d53e2c 1536 int ret = 0;
e3dc9f89 1537
455b2899
MH		 1538 if (!event || !group)
1539 return -EINVAL;
1540
b61387cb
MH		 1541 if (alloc_filter)
1542 size += sizeof(struct trace_uprobe_filter);
1543
1544 tp->event = kzalloc(size, GFP_KERNEL);
60d53e2c 1545 if (!tp->event)
455b2899
MH		 1546 return -ENOMEM;
1547
d59fae6f
MH		 1548 INIT_LIST_HEAD(&tp->event->files);
1549 INIT_LIST_HEAD(&tp->event->class.fields);
1550 INIT_LIST_HEAD(&tp->event->probes);
1551 INIT_LIST_HEAD(&tp->list);
fc9d276f 1552 list_add(&tp->list, &tp->event->probes);
d59fae6f 1553
60d53e2c
MH		 1554 call = trace_probe_event_call(tp);
1555 call->class = &tp->event->class;
1556 call->name = kstrdup(event, GFP_KERNEL);
1557 if (!call->name) {
1558 ret = -ENOMEM;
1559 goto error;
1560 }
1561
1562 tp->event->class.system = kstrdup(group, GFP_KERNEL);
1563 if (!tp->event->class.system) {
1564 ret = -ENOMEM;
1565 goto error;
455b2899 1566 }
455b2899
MH		 1567
1568 return 0;
60d53e2c
MH		 1569
1570error:
1571 trace_probe_cleanup(tp);
1572 return ret;
455b2899 1573}
46e5376d 1574
8e242060
MH		 1575static struct trace_event_call *
1576find_trace_event_call(const char *system, const char *event_name)
1577{
1578 struct trace_event_call *tp_event;
1579 const char *name;
1580
1581 list_for_each_entry(tp_event, &ftrace_events, list) {
1582 if (!tp_event->class->system ||
1583 strcmp(system, tp_event->class->system))
1584 continue;
1585 name = trace_event_name(tp_event);
1586 if (!name || strcmp(event_name, name))
1587 continue;
1588 return tp_event;
1589 }
1590
1591 return NULL;
1592}
1593
46e5376d
MH		 1594int trace_probe_register_event_call(struct trace_probe *tp)
1595{
e3dc9f89 1596 struct trace_event_call *call = trace_probe_event_call(tp);
46e5376d
MH		 1597 int ret;
1598
8e242060
MH		 1599 lockdep_assert_held(&event_mutex);
1600
1601 if (find_trace_event_call(trace_probe_group_name(tp),
1602 trace_probe_name(tp)))
1603 return -EEXIST;
1604
46e5376d
MH		 1605 ret = register_trace_event(&call->event);
1606 if (!ret)
1607 return -ENODEV;
1608
1609 ret = trace_add_event_call(call);
1610 if (ret)
1611 unregister_trace_event(&call->event);
1612
1613 return ret;
1614}
b5f935ee
MH		 1615
1616int trace_probe_add_file(struct trace_probe *tp, struct trace_event_file *file)
1617{
1618 struct event_file_link *link;
1619
1620 link = kmalloc(sizeof(*link), GFP_KERNEL);
1621 if (!link)
1622 return -ENOMEM;
1623
1624 link->file = file;
1625 INIT_LIST_HEAD(&link->list);
60d53e2c 1626 list_add_tail_rcu(&link->list, &tp->event->files);
747774d6 1627 trace_probe_set_flag(tp, TP_FLAG_TRACE);
b5f935ee
MH		 1628 return 0;
1629}
1630
1631struct event_file_link *trace_probe_get_file_link(struct trace_probe *tp,
1632 struct trace_event_file *file)
1633{
1634 struct event_file_link *link;
1635
1636 trace_probe_for_each_link(link, tp) {
1637 if (link->file == file)
1638 return link;
1639 }
1640
1641 return NULL;
1642}
1643
1644int trace_probe_remove_file(struct trace_probe *tp,
1645 struct trace_event_file *file)
1646{
1647 struct event_file_link *link;
1648
1649 link = trace_probe_get_file_link(tp, file);
1650 if (!link)
1651 return -ENOENT;
1652
1653 list_del_rcu(&link->list);
cae16f2c 1654 kvfree_rcu_mightsleep(link);
b5f935ee 1655
60d53e2c 1656 if (list_empty(&tp->event->files))
747774d6 1657 trace_probe_clear_flag(tp, TP_FLAG_TRACE);
b5f935ee
MH		 1658
1659 return 0;
1660}
ca89bc07
MH		 1661
1662/*
1663 * Return the smallest index of different type argument (start from 1).
1664 * If all argument types and name are same, return 0.
1665 */
1666int trace_probe_compare_arg_type(struct trace_probe *a, struct trace_probe *b)
1667{
1668 int i;
1669
d2aea95a
MH		 1670 /* In case of more arguments */
1671 if (a->nr_args < b->nr_args)
1672 return a->nr_args + 1;
1673 if (a->nr_args > b->nr_args)
1674 return b->nr_args + 1;
1675
ca89bc07
MH		 1676 for (i = 0; i < a->nr_args; i++) {
1677 if ((b->nr_args <= i) ||
1678 ((a->args[i].type != b->args[i].type) ||
1679 (a->args[i].count != b->args[i].count) ||
1680 strcmp(a->args[i].name, b->args[i].name)))
1681 return i + 1;
1682 }
1683
1684 return 0;
1685}
eb5bf813
MH		 1686
1687bool trace_probe_match_command_args(struct trace_probe *tp,
1688 int argc, const char **argv)
1689{
1690 char buf[MAX_ARGSTR_LEN + 1];
1691 int i;
1692
1693 if (tp->nr_args < argc)
1694 return false;
1695
1696 for (i = 0; i < argc; i++) {
1697 snprintf(buf, sizeof(buf), "%s=%s",
1698 tp->args[i].name, tp->args[i].comm);
1699 if (strcmp(buf, argv[i]))
1700 return false;
1701 }
1702 return true;
1703}
d262271d
MH		 1704
1705int trace_probe_create(const char *raw_command, int (*createfn)(int, const char **))
1706{
1707 int argc = 0, ret = 0;
1708 char **argv;
1709
1710 argv = argv_split(GFP_KERNEL, raw_command, &argc);
1711 if (!argv)
1712 return -ENOMEM;
1713
1714 if (argc)
1715 ret = createfn(argc, (const char **)argv);
1716
1717 argv_free(argv);
1718
1719 return ret;
1720}
196b6389
SC		 1721
1722int trace_probe_print_args(struct trace_seq *s, struct probe_arg *args, int nr_args,
1723 u8 *data, void *field)
1724{
1725 void *p;
1726 int i, j;
1727
1728 for (i = 0; i < nr_args; i++) {
1729 struct probe_arg *a = args + i;
1730
1731 trace_seq_printf(s, " %s=", a->name);
1732 if (likely(!a->count)) {
1733 if (!a->type->print(s, data + a->offset, field))
1734 return -ENOMEM;
1735 continue;
1736 }
1737 trace_seq_putc(s, '{');
1738 p = data + a->offset;
1739 for (j = 0; j < a->count; j++) {
1740 if (!a->type->print(s, p, field))
1741 return -ENOMEM;
1742 trace_seq_putc(s, j == a->count - 1 ? '}' : ',');
1743 p += a->type->size;
1744 }
1745 }
1746 return 0;
1747}
Linux 6.x block layer and io_uring tree(s)