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Merge tag 'soc-drivers-6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc
[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 14#include <linux/bpf.h>
ebeed8d4 15#include "trace_btf.h"
b576e097 16
8ab83f56
SD		 17#include "trace_probe.h"
18
ab105a4f
MH		 19#undef C
20#define C(a, b) b
21
22static const char *trace_probe_err_text[] = { ERRORS };
23
08416252 24static const char *reserved_field_names[] = {
8ab83f56
SD		 25 "common_type",
26 "common_flags",
27 "common_preempt_count",
28 "common_pid",
29 "common_tgid",
30 FIELD_STRING_IP,
31 FIELD_STRING_RETIP,
32 FIELD_STRING_FUNC,
33};
34
8ab83f56 35/* Printing in basic type function template */
17ce3dc7 36#define DEFINE_BASIC_PRINT_TYPE_FUNC(tname, type, fmt) \
56de7630 37int PRINT_TYPE_FUNC_NAME(tname)(struct trace_seq *s, void *data, void *ent)\
8ab83f56 38{ \
56de7630 39 trace_seq_printf(s, fmt, *(type *)data); \
d2b0191a 40 return !trace_seq_has_overflowed(s); \
8ab83f56 41} \
7bfbc63e 42const char PRINT_TYPE_FMT_NAME(tname)[] = fmt;
8ab83f56 43
bdca79c2
MH		 44DEFINE_BASIC_PRINT_TYPE_FUNC(u8, u8, "%u")
45DEFINE_BASIC_PRINT_TYPE_FUNC(u16, u16, "%u")
46DEFINE_BASIC_PRINT_TYPE_FUNC(u32, u32, "%u")
47DEFINE_BASIC_PRINT_TYPE_FUNC(u64, u64, "%Lu")
17ce3dc7
MH		 48DEFINE_BASIC_PRINT_TYPE_FUNC(s8, s8, "%d")
49DEFINE_BASIC_PRINT_TYPE_FUNC(s16, s16, "%d")
50DEFINE_BASIC_PRINT_TYPE_FUNC(s32, s32, "%d")
51DEFINE_BASIC_PRINT_TYPE_FUNC(s64, s64, "%Ld")
52DEFINE_BASIC_PRINT_TYPE_FUNC(x8, u8, "0x%x")
53DEFINE_BASIC_PRINT_TYPE_FUNC(x16, u16, "0x%x")
54DEFINE_BASIC_PRINT_TYPE_FUNC(x32, u32, "0x%x")
55DEFINE_BASIC_PRINT_TYPE_FUNC(x64, u64, "0x%Lx")
8478cca1 56DEFINE_BASIC_PRINT_TYPE_FUNC(char, u8, "'%c'")
8ab83f56 57
60c2e0ce
MH		 58int PRINT_TYPE_FUNC_NAME(symbol)(struct trace_seq *s, void *data, void *ent)
59{
60 trace_seq_printf(s, "%pS", (void *)*(unsigned long *)data);
61 return !trace_seq_has_overflowed(s);
62}
63const char PRINT_TYPE_FMT_NAME(symbol)[] = "%pS";
64
8ab83f56 65/* Print type function for string type */
56de7630 66int PRINT_TYPE_FUNC_NAME(string)(struct trace_seq *s, void *data, void *ent)
8ab83f56
SD		 67{
68 int len = *(u32 *)data >> 16;
69
70 if (!len)
4ed8f337 71 trace_seq_puts(s, FAULT_STRING);
8ab83f56 72 else
56de7630 73 trace_seq_printf(s, "\"%s\"",
d2b0191a
SRRH		 74 (const char *)get_loc_data(data, ent));
75 return !trace_seq_has_overflowed(s);
8ab83f56
SD		 76}
77
b26c74e1 78const char PRINT_TYPE_FMT_NAME(string)[] = "\\\"%s\\\"";
8ab83f56 79
f451bc89
MH		 80/* Fetch type information table */
81static const struct fetch_type probe_fetch_types[] = {
82 /* Special types */
b26a124c 83 __ASSIGN_FETCH_TYPE("string", string, string, sizeof(u32), 1, 1,
f451bc89 84 "__data_loc char[]"),
b26a124c
MHG		 85 __ASSIGN_FETCH_TYPE("ustring", string, string, sizeof(u32), 1, 1,
86 "__data_loc char[]"),
87 __ASSIGN_FETCH_TYPE("symstr", string, string, sizeof(u32), 1, 1,
88903c46 88 "__data_loc char[]"),
f451bc89
MH		 89 /* Basic types */
90 ASSIGN_FETCH_TYPE(u8, u8, 0),
91 ASSIGN_FETCH_TYPE(u16, u16, 0),
92 ASSIGN_FETCH_TYPE(u32, u32, 0),
93 ASSIGN_FETCH_TYPE(u64, u64, 0),
94 ASSIGN_FETCH_TYPE(s8, u8, 1),
95 ASSIGN_FETCH_TYPE(s16, u16, 1),
96 ASSIGN_FETCH_TYPE(s32, u32, 1),
97 ASSIGN_FETCH_TYPE(s64, u64, 1),
98 ASSIGN_FETCH_TYPE_ALIAS(x8, u8, u8, 0),
99 ASSIGN_FETCH_TYPE_ALIAS(x16, u16, u16, 0),
100 ASSIGN_FETCH_TYPE_ALIAS(x32, u32, u32, 0),
101 ASSIGN_FETCH_TYPE_ALIAS(x64, u64, u64, 0),
8478cca1 102 ASSIGN_FETCH_TYPE_ALIAS(char, u8, u8, 0),
60c2e0ce 103 ASSIGN_FETCH_TYPE_ALIAS(symbol, ADDR_FETCH_TYPE, ADDR_FETCH_TYPE, 0),
f451bc89
MH		 104
105 ASSIGN_FETCH_TYPE_END
106};
107
d4505aa6 108static const struct fetch_type *find_fetch_type(const char *type, unsigned long flags)
8ab83f56
SD		 109{
110 int i;
111
d4505aa6
MHG		 112 /* Reject the symbol/symstr for uprobes */
113 if (type && (flags & TPARG_FL_USER) &&
114 (!strcmp(type, "symbol") || !strcmp(type, "symstr")))
115 return NULL;
116
8ab83f56
SD		 117 if (!type)
118 type = DEFAULT_FETCH_TYPE_STR;
119
120 /* Special case: bitfield */
121 if (*type == 'b') {
122 unsigned long bs;
123
124 type = strchr(type, '/');
125 if (!type)
126 goto fail;
127
128 type++;
bcd83ea6 129 if (kstrtoul(type, 0, &bs))
8ab83f56
SD		 130 goto fail;
131
132 switch (bs) {
133 case 8:
d4505aa6 134 return find_fetch_type("u8", flags);
8ab83f56 135 case 16:
d4505aa6 136 return find_fetch_type("u16", flags);
8ab83f56 137 case 32:
d4505aa6 138 return find_fetch_type("u32", flags);
8ab83f56 139 case 64:
d4505aa6 140 return find_fetch_type("u64", flags);
8ab83f56
SD		 141 default:
142 goto fail;
143 }
144 }
145
f451bc89
MH		 146 for (i = 0; probe_fetch_types[i].name; i++) {
147 if (strcmp(type, probe_fetch_types[i].name) == 0)
148 return &probe_fetch_types[i];
34fee3a1 149 }
8ab83f56
SD		 150
151fail:
152 return NULL;
153}
154
ab105a4f
MH		 155static struct trace_probe_log trace_probe_log;
156
157void trace_probe_log_init(const char *subsystem, int argc, const char **argv)
158{
159 trace_probe_log.subsystem = subsystem;
160 trace_probe_log.argc = argc;
161 trace_probe_log.argv = argv;
162 trace_probe_log.index = 0;
163}
164
165void trace_probe_log_clear(void)
166{
167 memset(&trace_probe_log, 0, sizeof(trace_probe_log));
168}
169
170void trace_probe_log_set_index(int index)
171{
172 trace_probe_log.index = index;
173}
174
175void __trace_probe_log_err(int offset, int err_type)
176{
177 char *command, *p;
178 int i, len = 0, pos = 0;
179
180 if (!trace_probe_log.argv)
181 return;
182
f2cc020d 183 /* Recalculate the length and allocate buffer */
ab105a4f
MH		 184 for (i = 0; i < trace_probe_log.argc; i++) {
185 if (i == trace_probe_log.index)
186 pos = len;
187 len += strlen(trace_probe_log.argv[i]) + 1;
188 }
189 command = kzalloc(len, GFP_KERNEL);
190 if (!command)
191 return;
192
d2aea95a
MH		 193 if (trace_probe_log.index >= trace_probe_log.argc) {
194 /**
195 * Set the error position is next to the last arg + space.
196 * Note that len includes the terminal null and the cursor
f2cc020d 197 * appears at pos + 1.
d2aea95a
MH		 198 */
199 pos = len;
200 offset = 0;
201 }
202
ab105a4f
MH		 203 /* And make a command string from argv array */
204 p = command;
205 for (i = 0; i < trace_probe_log.argc; i++) {
206 len = strlen(trace_probe_log.argv[i]);
207 strcpy(p, trace_probe_log.argv[i]);
208 p[len] = ' ';
209 p += len + 1;
210 }
211 *(p - 1) = '\0';
212
2f754e77 213 tracing_log_err(NULL, trace_probe_log.subsystem, command,
ab105a4f
MH		 214 trace_probe_err_text, err_type, pos + offset);
215
216 kfree(command);
217}
218
8ab83f56 219/* Split symbol and offset. */
c5d343b6 220int traceprobe_split_symbol_offset(char *symbol, long *offset)
8ab83f56
SD		 221{
222 char *tmp;
223 int ret;
224
225 if (!offset)
226 return -EINVAL;
227
c5d343b6 228 tmp = strpbrk(symbol, "+-");
8ab83f56 229 if (tmp) {
c5d343b6 230 ret = kstrtol(tmp, 0, offset);
8ab83f56
SD		 231 if (ret)
232 return ret;
8ab83f56
SD		 233 *tmp = '\0';
234 } else
235 *offset = 0;
236
237 return 0;
238}
239
6212dd29
MH		 240/* @buf must has MAX_EVENT_NAME_LEN size */
241int traceprobe_parse_event_name(const char **pevent, const char **pgroup,
ab105a4f 242 char *buf, int offset)
6212dd29
MH		 243{
244 const char *slash, *event = *pevent;
dec65d79 245 int len;
6212dd29
MH		 246
247 slash = strchr(event, '/');
bc1b9734
SRV		 248 if (!slash)
249 slash = strchr(event, '.');
250
6212dd29
MH		 251 if (slash) {
252 if (slash == event) {
ab105a4f 253 trace_probe_log_err(offset, NO_GROUP_NAME);
6212dd29
MH		 254 return -EINVAL;
255 }
256 if (slash - event + 1 > MAX_EVENT_NAME_LEN) {
ab105a4f
MH		 257 trace_probe_log_err(offset, GROUP_TOO_LONG);
258 return -EINVAL;
6212dd29 259 }
c7dce4c5 260 strscpy(buf, event, slash - event + 1);
575b76cb 261 if (!is_good_system_name(buf)) {
ab105a4f 262 trace_probe_log_err(offset, BAD_GROUP_NAME);
5b7a9622
MH		 263 return -EINVAL;
264 }
6212dd29
MH		 265 *pgroup = buf;
266 *pevent = slash + 1;
ab105a4f 267 offset += slash - event + 1;
dec65d79 268 event = *pevent;
6212dd29 269 }
dec65d79
MH		 270 len = strlen(event);
271 if (len == 0) {
95c104c3
LY		 272 if (slash) {
273 *pevent = NULL;
274 return 0;
275 }
ab105a4f 276 trace_probe_log_err(offset, NO_EVENT_NAME);
6212dd29 277 return -EINVAL;
dec65d79 278 } else if (len > MAX_EVENT_NAME_LEN) {
ab105a4f
MH		 279 trace_probe_log_err(offset, EVENT_TOO_LONG);
280 return -EINVAL;
6212dd29 281 }
5b7a9622 282 if (!is_good_name(event)) {
ab105a4f 283 trace_probe_log_err(offset, BAD_EVENT_NAME);
5b7a9622
MH		 284 return -EINVAL;
285 }
6212dd29
MH		 286 return 0;
287}
288
1b8b0cd7
MHG		 289static int parse_trace_event_arg(char *arg, struct fetch_insn *code,
290 struct traceprobe_parse_context *ctx)
291{
292 struct ftrace_event_field *field;
293 struct list_head *head;
294
295 head = trace_get_fields(ctx->event);
296 list_for_each_entry(field, head, link) {
297 if (!strcmp(arg, field->name)) {
298 code->op = FETCH_OP_TP_ARG;
299 code->data = field;
300 return 0;
301 }
302 }
303 return -ENOENT;
304}
305
b576e097
MHG		 306#ifdef CONFIG_PROBE_EVENTS_BTF_ARGS
307
b576e097
MHG		 308static u32 btf_type_int(const struct btf_type *t)
309{
310 return *(u32 *)(t + 1);
311}
312
27973e5c
MHG		 313static bool btf_type_is_char_ptr(struct btf *btf, const struct btf_type *type)
314{
315 const struct btf_type *real_type;
316 u32 intdata;
317 s32 tid;
318
319 real_type = btf_type_skip_modifiers(btf, type->type, &tid);
320 if (!real_type)
321 return false;
322
323 if (BTF_INFO_KIND(real_type->info) != BTF_KIND_INT)
324 return false;
325
326 intdata = btf_type_int(real_type);
327 return !(BTF_INT_ENCODING(intdata) & BTF_INT_SIGNED)
328 && BTF_INT_BITS(intdata) == 8;
329}
330
331static bool btf_type_is_char_array(struct btf *btf, const struct btf_type *type)
332{
333 const struct btf_type *real_type;
334 const struct btf_array *array;
335 u32 intdata;
336 s32 tid;
337
338 if (BTF_INFO_KIND(type->info) != BTF_KIND_ARRAY)
339 return false;
340
341 array = (const struct btf_array *)(type + 1);
342
343 real_type = btf_type_skip_modifiers(btf, array->type, &tid);
344
345 intdata = btf_type_int(real_type);
346 return !(BTF_INT_ENCODING(intdata) & BTF_INT_SIGNED)
347 && BTF_INT_BITS(intdata) == 8;
348}
349
350static int check_prepare_btf_string_fetch(char *typename,
351 struct fetch_insn **pcode,
352 struct traceprobe_parse_context *ctx)
353{
354 struct btf *btf = ctx->btf;
355
356 if (!btf || !ctx->last_type)
357 return 0;
358
359 /* char [] does not need any change. */
360 if (btf_type_is_char_array(btf, ctx->last_type))
361 return 0;
362
363 /* char * requires dereference the pointer. */
364 if (btf_type_is_char_ptr(btf, ctx->last_type)) {
365 struct fetch_insn *code = *pcode + 1;
366
367 if (code->op == FETCH_OP_END) {
368 trace_probe_log_err(ctx->offset, TOO_MANY_OPS);
369 return -E2BIG;
370 }
371 if (typename[0] == 'u')
372 code->op = FETCH_OP_UDEREF;
373 else
374 code->op = FETCH_OP_DEREF;
375 code->offset = 0;
376 *pcode = code;
377 return 0;
378 }
379 /* Other types are not available for string */
380 trace_probe_log_err(ctx->offset, BAD_TYPE4STR);
381 return -EINVAL;
382}
383
c440adfb
MHG		 384static const char *fetch_type_from_btf_type(struct btf *btf,
385 const struct btf_type *type,
386 struct traceprobe_parse_context *ctx)
b576e097 387{
b576e097 388 u32 intdata;
b576e097
MHG		 389
390 /* TODO: const char * could be converted as a string */
c440adfb 391 switch (BTF_INFO_KIND(type->info)) {
b576e097
MHG		 392 case BTF_KIND_ENUM:
393 /* enum is "int", so convert to "s32" */
394 return "s32";
395 case BTF_KIND_ENUM64:
396 return "s64";
397 case BTF_KIND_PTR:
398 /* pointer will be converted to "x??" */
399 if (IS_ENABLED(CONFIG_64BIT))
400 return "x64";
401 else
402 return "x32";
403 case BTF_KIND_INT:
c440adfb 404 intdata = btf_type_int(type);
b576e097
MHG		 405 if (BTF_INT_ENCODING(intdata) & BTF_INT_SIGNED) {
406 switch (BTF_INT_BITS(intdata)) {
407 case 8:
408 return "s8";
409 case 16:
410 return "s16";
411 case 32:
412 return "s32";
413 case 64:
414 return "s64";
415 }
416 } else { /* unsigned */
417 switch (BTF_INT_BITS(intdata)) {
418 case 8:
419 return "u8";
420 case 16:
421 return "u16";
422 case 32:
423 return "u32";
424 case 64:
425 return "u64";
426 }
c440adfb
MHG		 427 /* bitfield, size is encoded in the type */
428 ctx->last_bitsize = BTF_INT_BITS(intdata);
429 ctx->last_bitoffs += BTF_INT_OFFSET(intdata);
430 return "u64";
b576e097
MHG		 431 }
432 }
433 /* TODO: support other types */
434
435 return NULL;
436}
437
d157d769 438static int query_btf_context(struct traceprobe_parse_context *ctx)
fd26290e
MHG		 439{
440 const struct btf_param *param;
d157d769 441 const struct btf_type *type;
b1d1e904 442 struct btf *btf;
d157d769 443 s32 nr;
fd26290e 444
d157d769
MHG		 445 if (ctx->btf)
446 return 0;
fd26290e 447
d157d769
MHG		 448 if (!ctx->funcname)
449 return -EINVAL;
fd26290e 450
d157d769
MHG		 451 type = btf_find_func_proto(ctx->funcname, &btf);
452 if (!type)
453 return -ENOENT;
b576e097 454
d157d769
MHG		 455 ctx->btf = btf;
456 ctx->proto = type;
457
458 /* ctx->params is optional, since func(void) will not have params. */
459 nr = 0;
460 param = btf_get_func_param(type, &nr);
461 if (!IS_ERR_OR_NULL(param)) {
462 /* Hide the first 'data' argument of tracepoint */
463 if (ctx->flags & TPARG_FL_TPOINT) {
464 nr--;
465 param++;
466 }
18b1e870
MHG		 467 }
468
d157d769
MHG		 469 if (nr > 0) {
470 ctx->nr_params = nr;
471 ctx->params = param;
472 } else {
473 ctx->nr_params = 0;
474 ctx->params = NULL;
b1d1e904
MHG		 475 }
476
d157d769 477 return 0;
b1d1e904
MHG		 478}
479
480static void clear_btf_context(struct traceprobe_parse_context *ctx)
481{
482 if (ctx->btf) {
483 btf_put(ctx->btf);
484 ctx->btf = NULL;
d157d769 485 ctx->proto = NULL;
b1d1e904
MHG		 486 ctx->params = NULL;
487 ctx->nr_params = 0;
488 }
b576e097
MHG		 489}
490
c440adfb
MHG		 491/* Return 1 if the field separater is arrow operator ('->') */
492static int split_next_field(char *varname, char **next_field,
493 struct traceprobe_parse_context *ctx)
494{
495 char *field;
496 int ret = 0;
497
498 field = strpbrk(varname, ".-");
499 if (field) {
500 if (field[0] == '-' && field[1] == '>') {
501 field[0] = '\0';
502 field += 2;
503 ret = 1;
504 } else if (field[0] == '.') {
505 field[0] = '\0';
506 field += 1;
507 } else {
508 trace_probe_log_err(ctx->offset + field - varname, BAD_HYPHEN);
509 return -EINVAL;
510 }
511 *next_field = field;
512 }
513
514 return ret;
515}
516
517/*
518 * Parse the field of data structure. The @type must be a pointer type
519 * pointing the target data structure type.
520 */
521static int parse_btf_field(char *fieldname, const struct btf_type *type,
522 struct fetch_insn **pcode, struct fetch_insn *end,
523 struct traceprobe_parse_context *ctx)
524{
525 struct fetch_insn *code = *pcode;
526 const struct btf_member *field;
527 u32 bitoffs, anon_offs;
528 char *next;
529 int is_ptr;
530 s32 tid;
531
532 do {
533 /* Outer loop for solving arrow operator ('->') */
534 if (BTF_INFO_KIND(type->info) != BTF_KIND_PTR) {
535 trace_probe_log_err(ctx->offset, NO_PTR_STRCT);
536 return -EINVAL;
537 }
538 /* Convert a struct pointer type to a struct type */
539 type = btf_type_skip_modifiers(ctx->btf, type->type, &tid);
540 if (!type) {
541 trace_probe_log_err(ctx->offset, BAD_BTF_TID);
542 return -EINVAL;
543 }
544
545 bitoffs = 0;
546 do {
547 /* Inner loop for solving dot operator ('.') */
548 next = NULL;
549 is_ptr = split_next_field(fieldname, &next, ctx);
550 if (is_ptr < 0)
551 return is_ptr;
552
553 anon_offs = 0;
554 field = btf_find_struct_member(ctx->btf, type, fieldname,
555 &anon_offs);
556 if (!field) {
557 trace_probe_log_err(ctx->offset, NO_BTF_FIELD);
558 return -ENOENT;
559 }
560 /* Add anonymous structure/union offset */
561 bitoffs += anon_offs;
562
563 /* Accumulate the bit-offsets of the dot-connected fields */
564 if (btf_type_kflag(type)) {
565 bitoffs += BTF_MEMBER_BIT_OFFSET(field->offset);
566 ctx->last_bitsize = BTF_MEMBER_BITFIELD_SIZE(field->offset);
567 } else {
568 bitoffs += field->offset;
569 ctx->last_bitsize = 0;
570 }
571
572 type = btf_type_skip_modifiers(ctx->btf, field->type, &tid);
573 if (!type) {
574 trace_probe_log_err(ctx->offset, BAD_BTF_TID);
575 return -EINVAL;
576 }
577
578 ctx->offset += next - fieldname;
579 fieldname = next;
580 } while (!is_ptr && fieldname);
581
582 if (++code == end) {
583 trace_probe_log_err(ctx->offset, TOO_MANY_OPS);
584 return -EINVAL;
585 }
586 code->op = FETCH_OP_DEREF; /* TODO: user deref support */
587 code->offset = bitoffs / 8;
588 *pcode = code;
589
590 ctx->last_bitoffs = bitoffs % 8;
591 ctx->last_type = type;
592 } while (fieldname);
593
594 return 0;
595}
596
597static int parse_btf_arg(char *varname,
598 struct fetch_insn **pcode, struct fetch_insn *end,
b576e097
MHG		 599 struct traceprobe_parse_context *ctx)
600{
c440adfb 601 struct fetch_insn *code = *pcode;
b576e097 602 const struct btf_param *params;
c440adfb
MHG		 603 const struct btf_type *type;
604 char *field = NULL;
d157d769 605 int i, is_ptr, ret;
c440adfb 606 u32 tid;
b576e097 607
b576e097
MHG		 608 if (WARN_ON_ONCE(!ctx->funcname))
609 return -EINVAL;
610
c440adfb
MHG		 611 is_ptr = split_next_field(varname, &field, ctx);
612 if (is_ptr < 0)
613 return is_ptr;
614 if (!is_ptr && field) {
615 /* dot-connected field on an argument is not supported. */
616 trace_probe_log_err(ctx->offset + field - varname,
617 NOSUP_DAT_ARG);
618 return -EOPNOTSUPP;
619 }
620
d157d769
MHG		 621 if (ctx->flags & TPARG_FL_RETURN) {
622 if (strcmp(varname, "$retval") != 0) {
623 trace_probe_log_err(ctx->offset, NO_BTFARG);
624 return -ENOENT;
625 }
626 code->op = FETCH_OP_RETVAL;
627 /* Check whether the function return type is not void */
628 if (query_btf_context(ctx) == 0) {
629 if (ctx->proto->type == 0) {
630 trace_probe_log_err(ctx->offset, NO_RETVAL);
631 return -ENOENT;
632 }
633 tid = ctx->proto->type;
634 goto found;
635 }
636 if (field) {
637 trace_probe_log_err(ctx->offset + field - varname,
638 NO_BTF_ENTRY);
639 return -ENOENT;
640 }
641 return 0;
642 }
643
644 if (!ctx->btf) {
645 ret = query_btf_context(ctx);
646 if (ret < 0 || ctx->nr_params == 0) {
b576e097
MHG		 647 trace_probe_log_err(ctx->offset, NO_BTF_ENTRY);
648 return PTR_ERR(params);
649 }
d157d769
MHG		 650 }
651 params = ctx->params;
b576e097
MHG		 652
653 for (i = 0; i < ctx->nr_params; i++) {
b1d1e904 654 const char *name = btf_name_by_offset(ctx->btf, params[i].name_off);
b576e097
MHG		 655
656 if (name && !strcmp(name, varname)) {
657 code->op = FETCH_OP_ARG;
53431798
MHG		 658 if (ctx->flags & TPARG_FL_TPOINT)
659 code->param = i + 1;
660 else
661 code->param = i;
c440adfb
MHG		 662 tid = params[i].type;
663 goto found;
b576e097
MHG		 664 }
665 }
666 trace_probe_log_err(ctx->offset, NO_BTFARG);
667 return -ENOENT;
c440adfb
MHG		 668
669found:
670 type = btf_type_skip_modifiers(ctx->btf, tid, &tid);
671 if (!type) {
672 trace_probe_log_err(ctx->offset, BAD_BTF_TID);
673 return -EINVAL;
674 }
675 /* Initialize the last type information */
676 ctx->last_type = type;
677 ctx->last_bitoffs = 0;
678 ctx->last_bitsize = 0;
679 if (field) {
680 ctx->offset += field - varname;
681 return parse_btf_field(field, type, pcode, end, ctx);
682 }
683 return 0;
b576e097
MHG		 684}
685
d157d769 686static const struct fetch_type *find_fetch_type_from_btf_type(
b576e097
MHG		 687 struct traceprobe_parse_context *ctx)
688{
b1d1e904 689 struct btf *btf = ctx->btf;
b576e097
MHG		 690 const char *typestr = NULL;
691
c440adfb
MHG		 692 if (btf && ctx->last_type)
693 typestr = fetch_type_from_btf_type(btf, ctx->last_type, ctx);
b576e097
MHG		 694
695 return find_fetch_type(typestr, ctx->flags);
696}
18b1e870 697
c440adfb
MHG		 698static int parse_btf_bitfield(struct fetch_insn **pcode,
699 struct traceprobe_parse_context *ctx)
700{
701 struct fetch_insn *code = *pcode;
702
703 if ((ctx->last_bitsize % 8 == 0) && ctx->last_bitoffs == 0)
704 return 0;
705
706 code++;
707 if (code->op != FETCH_OP_NOP) {
708 trace_probe_log_err(ctx->offset, TOO_MANY_OPS);
709 return -EINVAL;
710 }
711 *pcode = code;
712
713 code->op = FETCH_OP_MOD_BF;
714 code->lshift = 64 - (ctx->last_bitsize + ctx->last_bitoffs);
715 code->rshift = 64 - ctx->last_bitsize;
716 code->basesize = 64 / 8;
717 return 0;
718}
719
b576e097 720#else
b1d1e904 721static void clear_btf_context(struct traceprobe_parse_context *ctx)
b576e097 722{
b1d1e904 723 ctx->btf = NULL;
b576e097
MHG		 724}
725
d157d769 726static int query_btf_context(struct traceprobe_parse_context *ctx)
18b1e870 727{
d157d769 728 return -EOPNOTSUPP;
18b1e870
MHG		 729}
730
c440adfb
MHG		 731static int parse_btf_arg(char *varname,
732 struct fetch_insn **pcode, struct fetch_insn *end,
b576e097
MHG		 733 struct traceprobe_parse_context *ctx)
734{
735 trace_probe_log_err(ctx->offset, NOSUP_BTFARG);
736 return -EOPNOTSUPP;
737}
fd26290e 738
c440adfb
MHG		 739static int parse_btf_bitfield(struct fetch_insn **pcode,
740 struct traceprobe_parse_context *ctx)
741{
742 trace_probe_log_err(ctx->offset, NOSUP_BTFARG);
743 return -EOPNOTSUPP;
744}
745
d157d769 746#define find_fetch_type_from_btf_type(ctx) \
b576e097 747 find_fetch_type(NULL, ctx->flags)
fd26290e 748
27973e5c
MHG		 749static int check_prepare_btf_string_fetch(char *typename,
750 struct fetch_insn **pcode,
751 struct traceprobe_parse_context *ctx)
752{
753 return 0;
754}
755
b576e097
MHG		 756#endif
757
8ab83f56
SD		 758#define PARAM_MAX_STACK (THREAD_SIZE / sizeof(unsigned long))
759
d157d769
MHG		 760/* Parse $vars. @orig_arg points '$', which syncs to @ctx->offset */
761static int parse_probe_vars(char *orig_arg, const struct fetch_type *t,
762 struct fetch_insn **pcode,
763 struct fetch_insn *end,
1b8b0cd7 764 struct traceprobe_parse_context *ctx)
8ab83f56 765{
d157d769 766 struct fetch_insn *code = *pcode;
1b8b0cd7 767 int err = TP_ERR_BAD_VAR;
d157d769
MHG		 768 char *arg = orig_arg + 1;
769 unsigned long param;
3d739c1f
SRV		 770 int ret = 0;
771 int len;
8ab83f56 772
1b8b0cd7 773 if (ctx->flags & TPARG_FL_TEVENT) {
2673c60e
SRG		 774 if (code->data)
775 return -EFAULT;
1b8b0cd7
MHG		 776 ret = parse_trace_event_arg(arg, code, ctx);
777 if (!ret)
778 return 0;
779 if (strcmp(arg, "comm") == 0 || strcmp(arg, "COMM") == 0) {
780 code->op = FETCH_OP_COMM;
781 return 0;
782 }
783 /* backward compatibility */
784 ctx->offset = 0;
785 goto inval;
786 }
787
d157d769
MHG		 788 if (str_has_prefix(arg, "retval")) {
789 if (!(ctx->flags & TPARG_FL_RETURN)) {
790 err = TP_ERR_RETVAL_ON_PROBE;
791 goto inval;
792 }
793 if (!(ctx->flags & TPARG_FL_KERNEL) ||
794 !IS_ENABLED(CONFIG_PROBE_EVENTS_BTF_ARGS)) {
53305928 795 code->op = FETCH_OP_RETVAL;
1b8b0cd7 796 return 0;
ab105a4f 797 }
d157d769 798 return parse_btf_arg(orig_arg, pcode, end, ctx);
1b8b0cd7
MHG		 799 }
800
801 len = str_has_prefix(arg, "stack");
802 if (len) {
803
3d739c1f 804 if (arg[len] == '\0') {
53305928 805 code->op = FETCH_OP_STACKP;
1b8b0cd7
MHG		 806 return 0;
807 }
808
809 if (isdigit(arg[len])) {
3d739c1f 810 ret = kstrtoul(arg + len, 10, &param);
1b8b0cd7
MHG		 811 if (ret)
812 goto inval;
813
814 if ((ctx->flags & TPARG_FL_KERNEL) &&
815 param > PARAM_MAX_STACK) {
816 err = TP_ERR_BAD_STACK_NUM;
817 goto inval;
8ab83f56 818 }
1b8b0cd7
MHG		 819 code->op = FETCH_OP_STACK;
820 code->param = (unsigned int)param;
821 return 0;
822 }
823 goto inval;
824 }
825
826 if (strcmp(arg, "comm") == 0 || strcmp(arg, "COMM") == 0) {
53305928 827 code->op = FETCH_OP_COMM;
1b8b0cd7
MHG		 828 return 0;
829 }
830
a1303af5 831#ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API
1b8b0cd7
MHG		 832 len = str_has_prefix(arg, "arg");
833 if (len && tparg_is_function_entry(ctx->flags)) {
3d739c1f 834 ret = kstrtoul(arg + len, 10, &param);
1b8b0cd7
MHG		 835 if (ret)
836 goto inval;
837
838 if (!param || param > PARAM_MAX_STACK) {
839 err = TP_ERR_BAD_ARG_NUM;
840 goto inval;
ab105a4f 841 }
1b8b0cd7 842
a1303af5
MH		 843 code->op = FETCH_OP_ARG;
844 code->param = (unsigned int)param - 1;
e2d0d7b2
MHG		 845 /*
846 * The tracepoint probe will probe a stub function, and the
847 * first parameter of the stub is a dummy and should be ignored.
848 */
1b8b0cd7 849 if (ctx->flags & TPARG_FL_TPOINT)
e2d0d7b2 850 code->param++;
1b8b0cd7
MHG		 851 return 0;
852 }
a1303af5 853#endif
ab105a4f 854
1b8b0cd7
MHG		 855inval:
856 __trace_probe_log_err(ctx->offset, err);
ab105a4f 857 return -EINVAL;
8ab83f56
SD		 858}
859
6218bf9f
MH		 860static int str_to_immediate(char *str, unsigned long *imm)
861{
862 if (isdigit(str[0]))
863 return kstrtoul(str, 0, imm);
864 else if (str[0] == '-')
865 return kstrtol(str, 0, (long *)imm);
866 else if (str[0] == '+')
867 return kstrtol(str + 1, 0, (long *)imm);
868 return -EINVAL;
869}
870
a42e3c4d
MH		 871static int __parse_imm_string(char *str, char **pbuf, int offs)
872{
873 size_t len = strlen(str);
874
875 if (str[len - 1] != '"') {
876 trace_probe_log_err(offs + len, IMMSTR_NO_CLOSE);
877 return -EINVAL;
878 }
879 *pbuf = kstrndup(str, len - 1, GFP_KERNEL);
1c1857d4
XW		 880 if (!*pbuf)
881 return -ENOMEM;
a42e3c4d
MH		 882 return 0;
883}
884
8ab83f56 885/* Recursive argument parser */
53305928
MH		 886static int
887parse_probe_arg(char *arg, const struct fetch_type *type,
888 struct fetch_insn **pcode, struct fetch_insn *end,
1b8b0cd7 889 struct traceprobe_parse_context *ctx)
8ab83f56 890{
53305928 891 struct fetch_insn *code = *pcode;
8ab83f56 892 unsigned long param;
e65f7ae7 893 int deref = FETCH_OP_DEREF;
bf173ca9 894 long offset = 0;
8ab83f56 895 char *tmp;
34fee3a1 896 int ret = 0;
8ab83f56 897
8ab83f56
SD		 898 switch (arg[0]) {
899 case '$':
d157d769 900 ret = parse_probe_vars(arg, type, pcode, end, ctx);
8ab83f56
SD		 901 break;
902
903 case '%': /* named register */
1b8b0cd7 904 if (ctx->flags & (TPARG_FL_TEVENT | TPARG_FL_FPROBE)) {
334e5519 905 /* eprobe and fprobe do not handle registers */
1b8b0cd7 906 trace_probe_log_err(ctx->offset, BAD_VAR);
2673c60e
SRG		 907 break;
908 }
8ab83f56
SD		 909 ret = regs_query_register_offset(arg + 1);
910 if (ret >= 0) {
53305928
MH		 911 code->op = FETCH_OP_REG;
912 code->param = (unsigned int)ret;
8ab83f56 913 ret = 0;
ab105a4f 914 } else
1b8b0cd7 915 trace_probe_log_err(ctx->offset, BAD_REG_NAME);
8ab83f56
SD		 916 break;
917
b7e0bf34 918 case '@': /* memory, file-offset or symbol */
8ab83f56 919 if (isdigit(arg[1])) {
bcd83ea6 920 ret = kstrtoul(arg + 1, 0, &param);
ab105a4f 921 if (ret) {
1b8b0cd7 922 trace_probe_log_err(ctx->offset, BAD_MEM_ADDR);
8ab83f56 923 break;
ab105a4f 924 }
53305928
MH		 925 /* load address */
926 code->op = FETCH_OP_IMM;
927 code->immediate = param;
b7e0bf34
NK		 928 } else if (arg[1] == '+') {
929 /* kprobes don't support file offsets */
1b8b0cd7
MHG		 930 if (ctx->flags & TPARG_FL_KERNEL) {
931 trace_probe_log_err(ctx->offset, FILE_ON_KPROBE);
b7e0bf34 932 return -EINVAL;
ab105a4f 933 }
b7e0bf34 934 ret = kstrtol(arg + 2, 0, &offset);
ab105a4f 935 if (ret) {
1b8b0cd7 936 trace_probe_log_err(ctx->offset, BAD_FILE_OFFS);
b7e0bf34 937 break;
ab105a4f 938 }
b7e0bf34 939
53305928
MH		 940 code->op = FETCH_OP_FOFFS;
941 code->immediate = (unsigned long)offset; // imm64?
8ab83f56 942 } else {
b079d374 943 /* uprobes don't support symbols */
1b8b0cd7
MHG		 944 if (!(ctx->flags & TPARG_FL_KERNEL)) {
945 trace_probe_log_err(ctx->offset, SYM_ON_UPROBE);
b079d374 946 return -EINVAL;
ab105a4f 947 }
a6682814
MH		 948 /* Preserve symbol for updating */
949 code->op = FETCH_NOP_SYMBOL;
950 code->data = kstrdup(arg + 1, GFP_KERNEL);
951 if (!code->data)
952 return -ENOMEM;
ab105a4f 953 if (++code == end) {
1b8b0cd7 954 trace_probe_log_err(ctx->offset, TOO_MANY_OPS);
ab105a4f
MH		 955 return -EINVAL;
956 }
53305928 957 code->op = FETCH_OP_IMM;
a6682814 958 code->immediate = 0;
8ab83f56 959 }
53305928 960 /* These are fetching from memory */
ab105a4f 961 if (++code == end) {
1b8b0cd7 962 trace_probe_log_err(ctx->offset, TOO_MANY_OPS);
ab105a4f
MH		 963 return -EINVAL;
964 }
53305928
MH		 965 *pcode = code;
966 code->op = FETCH_OP_DEREF;
967 code->offset = offset;
8ab83f56
SD		 968 break;
969
970 case '+': /* deref memory */
8ab83f56 971 case '-':
e65f7ae7
MH		 972 if (arg[1] == 'u') {
973 deref = FETCH_OP_UDEREF;
974 arg[1] = arg[0];
975 arg++;
976 }
977 if (arg[0] == '+')
978 arg++; /* Skip '+', because kstrtol() rejects it. */
8ab83f56 979 tmp = strchr(arg, '(');
ab105a4f 980 if (!tmp) {
1b8b0cd7 981 trace_probe_log_err(ctx->offset, DEREF_NEED_BRACE);
53305928 982 return -EINVAL;
ab105a4f 983 }
8ab83f56 984 *tmp = '\0';
bcd83ea6 985 ret = kstrtol(arg, 0, &offset);
ab105a4f 986 if (ret) {
1b8b0cd7 987 trace_probe_log_err(ctx->offset, BAD_DEREF_OFFS);
8ab83f56 988 break;
ab105a4f 989 }
1b8b0cd7 990 ctx->offset += (tmp + 1 - arg) + (arg[0] != '-' ? 1 : 0);
8ab83f56
SD		 991 arg = tmp + 1;
992 tmp = strrchr(arg, ')');
ab105a4f 993 if (!tmp) {
1b8b0cd7 994 trace_probe_log_err(ctx->offset + strlen(arg),
ab105a4f
MH		 995 DEREF_OPEN_BRACE);
996 return -EINVAL;
997 } else {
1b8b0cd7
MHG		 998 const struct fetch_type *t2 = find_fetch_type(NULL, ctx->flags);
999 int cur_offs = ctx->offset;
8ab83f56 1000
8ab83f56 1001 *tmp = '\0';
1b8b0cd7 1002 ret = parse_probe_arg(arg, t2, &code, end, ctx);
8ab83f56 1003 if (ret)
53305928 1004 break;
1b8b0cd7 1005 ctx->offset = cur_offs;
a42e3c4d
MH		 1006 if (code->op == FETCH_OP_COMM ||
1007 code->op == FETCH_OP_DATA) {
1b8b0cd7 1008 trace_probe_log_err(ctx->offset, COMM_CANT_DEREF);
ab105a4f
MH		 1009 return -EINVAL;
1010 }
1011 if (++code == end) {
1b8b0cd7 1012 trace_probe_log_err(ctx->offset, TOO_MANY_OPS);
53305928 1013 return -EINVAL;
ab105a4f 1014 }
53305928
MH		 1015 *pcode = code;
1016
e65f7ae7 1017 code->op = deref;
53305928 1018 code->offset = offset;
c440adfb
MHG		 1019 /* Reset the last type if used */
1020 ctx->last_type = NULL;
8ab83f56
SD		 1021 }
1022 break;
6218bf9f 1023 case '\\': /* Immediate value */
a42e3c4d 1024 if (arg[1] == '"') { /* Immediate string */
1b8b0cd7 1025 ret = __parse_imm_string(arg + 2, &tmp, ctx->offset + 2);
a42e3c4d
MH		 1026 if (ret)
1027 break;
1028 code->op = FETCH_OP_DATA;
1029 code->data = tmp;
1030 } else {
1031 ret = str_to_immediate(arg + 1, &code->immediate);
1032 if (ret)
1b8b0cd7 1033 trace_probe_log_err(ctx->offset + 1, BAD_IMM);
a42e3c4d
MH		 1034 else
1035 code->op = FETCH_OP_IMM;
1036 }
6218bf9f 1037 break;
b576e097
MHG		 1038 default:
1039 if (isalpha(arg[0]) || arg[0] == '_') { /* BTF variable */
1040 if (!tparg_is_function_entry(ctx->flags)) {
1041 trace_probe_log_err(ctx->offset, NOSUP_BTFARG);
1042 return -EINVAL;
1043 }
c440adfb 1044 ret = parse_btf_arg(arg, pcode, end, ctx);
b576e097
MHG		 1045 break;
1046 }
8ab83f56 1047 }
53305928
MH		 1048 if (!ret && code->op == FETCH_OP_NOP) {
1049 /* Parsed, but do not find fetch method */
1b8b0cd7 1050 trace_probe_log_err(ctx->offset, BAD_FETCH_ARG);
8ab83f56
SD		 1051 ret = -EINVAL;
1052 }
8ab83f56
SD		 1053 return ret;
1054}
1055
1056#define BYTES_TO_BITS(nb) ((BITS_PER_LONG * (nb)) / sizeof(long))
1057
1058/* Bitfield type needs to be parsed into a fetch function */
1059static int __parse_bitfield_probe_arg(const char *bf,
1060 const struct fetch_type *t,
53305928 1061 struct fetch_insn **pcode)
8ab83f56 1062{
53305928 1063 struct fetch_insn *code = *pcode;
8ab83f56
SD		 1064 unsigned long bw, bo;
1065 char *tail;
1066
1067 if (*bf != 'b')
1068 return 0;
1069
8ab83f56
SD		 1070 bw = simple_strtoul(bf + 1, &tail, 0); /* Use simple one */
1071
1072 if (bw == 0 || *tail != '@')
1073 return -EINVAL;
1074
1075 bf = tail + 1;
1076 bo = simple_strtoul(bf, &tail, 0);
1077
1078 if (tail == bf || *tail != '/')
1079 return -EINVAL;
53305928
MH		 1080 code++;
1081 if (code->op != FETCH_OP_NOP)
ab105a4f 1082 return -EINVAL;
53305928 1083 *pcode = code;
8ab83f56 1084
53305928
MH		 1085 code->op = FETCH_OP_MOD_BF;
1086 code->lshift = BYTES_TO_BITS(t->size) - (bw + bo);
1087 code->rshift = BYTES_TO_BITS(t->size) - bw;
1088 code->basesize = t->size;
8ab83f56
SD		 1089
1090 return (BYTES_TO_BITS(t->size) < (bw + bo)) ? -EINVAL : 0;
1091}
1092
1093/* String length checking wrapper */
fcd9db51 1094static int traceprobe_parse_probe_arg_body(const char *argv, ssize_t *size,
1b8b0cd7
MHG		 1095 struct probe_arg *parg,
1096 struct traceprobe_parse_context *ctx)
8ab83f56 1097{
40b53b77 1098 struct fetch_insn *code, *scode, *tmp = NULL;
ab105a4f 1099 char *t, *t2, *t3;
40b53b77 1100 int ret, len;
1b8b0cd7 1101 char *arg;
8ab83f56 1102
fcd9db51
SRV		 1103 arg = kstrdup(argv, GFP_KERNEL);
1104 if (!arg)
1105 return -ENOMEM;
1106
1107 ret = -EINVAL;
ab105a4f
MH		 1108 len = strlen(arg);
1109 if (len > MAX_ARGSTR_LEN) {
1b8b0cd7 1110 trace_probe_log_err(ctx->offset, ARG_TOO_LONG);
fcd9db51 1111 goto out;
ab105a4f 1112 } else if (len == 0) {
1b8b0cd7 1113 trace_probe_log_err(ctx->offset, NO_ARG_BODY);
fcd9db51 1114 goto out;
8ab83f56 1115 }
ab105a4f 1116
fcd9db51 1117 ret = -ENOMEM;
8ab83f56 1118 parg->comm = kstrdup(arg, GFP_KERNEL);
ab105a4f 1119 if (!parg->comm)
fcd9db51 1120 goto out;
ab105a4f 1121
fcd9db51 1122 ret = -EINVAL;
40b53b77 1123 t = strchr(arg, ':');
8ab83f56 1124 if (t) {
40b53b77
MH		 1125 *t = '\0';
1126 t2 = strchr(++t, '[');
1127 if (t2) {
ab105a4f
MH		 1128 *t2++ = '\0';
1129 t3 = strchr(t2, ']');
1130 if (!t3) {
1b8b0cd7
MHG		 1131 int offs = t2 + strlen(t2) - arg;
1132
1133 trace_probe_log_err(ctx->offset + offs,
ab105a4f 1134 ARRAY_NO_CLOSE);
fcd9db51 1135 goto out;
ab105a4f 1136 } else if (t3[1] != '\0') {
1b8b0cd7 1137 trace_probe_log_err(ctx->offset + t3 + 1 - arg,
ab105a4f 1138 BAD_ARRAY_SUFFIX);
fcd9db51 1139 goto out;
ab105a4f
MH		 1140 }
1141 *t3 = '\0';
1142 if (kstrtouint(t2, 0, &parg->count) || !parg->count) {
1b8b0cd7 1143 trace_probe_log_err(ctx->offset + t2 - arg,
ab105a4f 1144 BAD_ARRAY_NUM);
fcd9db51 1145 goto out;
ab105a4f
MH		 1146 }
1147 if (parg->count > MAX_ARRAY_LEN) {
1b8b0cd7 1148 trace_probe_log_err(ctx->offset + t2 - arg,
ab105a4f 1149 ARRAY_TOO_BIG);
fcd9db51 1150 goto out;
ab105a4f 1151 }
40b53b77 1152 }
8ab83f56 1153 }
3dd1f7f2 1154
a42e3c4d 1155 /*
f2cc020d 1156 * Since $comm and immediate string can not be dereferenced,
02333de9 1157 * we can find those by strcmp. But ignore for eprobes.
a42e3c4d 1158 */
1b8b0cd7 1159 if (!(ctx->flags & TPARG_FL_TEVENT) &&
ab838444
SRG		 1160 (strcmp(arg, "$comm") == 0 || strcmp(arg, "$COMM") == 0 ||
1161 strncmp(arg, "\\\"", 2) == 0)) {
8c427cc2
MHG		 1162 /* The type of $comm must be "string", and not an array type. */
1163 if (parg->count || (t && strcmp(t, "string"))) {
1164 trace_probe_log_err(ctx->offset + (t ? (t - arg) : 0),
1165 NEED_STRING_TYPE);
fcd9db51 1166 goto out;
8c427cc2 1167 }
1b8b0cd7 1168 parg->type = find_fetch_type("string", ctx->flags);
3dd1f7f2 1169 } else
1b8b0cd7 1170 parg->type = find_fetch_type(t, ctx->flags);
8ab83f56 1171 if (!parg->type) {
1b8b0cd7 1172 trace_probe_log_err(ctx->offset + (t ? (t - arg) : 0), BAD_TYPE);
fcd9db51 1173 goto out;
8ab83f56 1174 }
8ab83f56 1175
8623b006 1176 code = tmp = kcalloc(FETCH_INSN_MAX, sizeof(*code), GFP_KERNEL);
53305928 1177 if (!code)
fcd9db51 1178 goto out;
53305928
MH		 1179 code[FETCH_INSN_MAX - 1].op = FETCH_OP_END;
1180
c440adfb 1181 ctx->last_type = NULL;
53305928 1182 ret = parse_probe_arg(arg, parg->type, &code, &code[FETCH_INSN_MAX - 1],
1b8b0cd7 1183 ctx);
53305928
MH		 1184 if (ret)
1185 goto fail;
1186
b576e097 1187 /* Update storing type if BTF is available */
d157d769 1188 if (IS_ENABLED(CONFIG_PROBE_EVENTS_BTF_ARGS) &&
27973e5c
MHG		 1189 ctx->last_type) {
1190 if (!t) {
1191 parg->type = find_fetch_type_from_btf_type(ctx);
1192 } else if (strstr(t, "string")) {
1193 ret = check_prepare_btf_string_fetch(t, &code, ctx);
1194 if (ret)
1195 goto fail;
1196 }
1197 }
9a571c1e
MHG		 1198 parg->offset = *size;
1199 *size += parg->type->size * (parg->count ?: 1);
1200
1201 if (parg->count) {
1202 len = strlen(parg->type->fmttype) + 6;
1203 parg->fmt = kmalloc(len, GFP_KERNEL);
1204 if (!parg->fmt) {
1205 ret = -ENOMEM;
1206 goto out;
1207 }
1208 snprintf(parg->fmt, len, "%s[%d]", parg->type->fmttype,
1209 parg->count);
1210 }
b576e097 1211
fcd9db51 1212 ret = -EINVAL;
53305928 1213 /* Store operation */
b26a124c
MHG		 1214 if (parg->type->is_string) {
1215 if (!strcmp(parg->type->name, "symstr")) {
1216 if (code->op != FETCH_OP_REG && code->op != FETCH_OP_STACK &&
1217 code->op != FETCH_OP_RETVAL && code->op != FETCH_OP_ARG &&
1218 code->op != FETCH_OP_DEREF && code->op != FETCH_OP_TP_ARG) {
1b8b0cd7 1219 trace_probe_log_err(ctx->offset + (t ? (t - arg) : 0),
b26a124c
MHG		 1220 BAD_SYMSTRING);
1221 goto fail;
1222 }
1223 } else {
1224 if (code->op != FETCH_OP_DEREF && code->op != FETCH_OP_UDEREF &&
1225 code->op != FETCH_OP_IMM && code->op != FETCH_OP_COMM &&
1226 code->op != FETCH_OP_DATA && code->op != FETCH_OP_TP_ARG) {
1b8b0cd7 1227 trace_probe_log_err(ctx->offset + (t ? (t - arg) : 0),
b26a124c
MHG		 1228 BAD_STRING);
1229 goto fail;
1230 }
53305928 1231 }
b26a124c
MHG		 1232 if (!strcmp(parg->type->name, "symstr") ||
1233 (code->op == FETCH_OP_IMM || code->op == FETCH_OP_COMM ||
7491e2c4
TSV		 1234 code->op == FETCH_OP_DATA) || code->op == FETCH_OP_TP_ARG ||
1235 parg->count) {
40b53b77 1236 /*
a42e3c4d
MH		 1237 * IMM, DATA and COMM is pointing actual address, those
1238 * must be kept, and if parg->count != 0, this is an
1239 * array of string pointers instead of string address
1240 * itself.
b26a124c
MHG		 1241 * For the symstr, it doesn't need to dereference, thus
1242 * it just get the value.
40b53b77 1243 */
53305928 1244 code++;
40b53b77 1245 if (code->op != FETCH_OP_NOP) {
1b8b0cd7 1246 trace_probe_log_err(ctx->offset, TOO_MANY_OPS);
40b53b77
MH		 1247 goto fail;
1248 }
1249 }
88903c46 1250 /* If op == DEREF, replace it with STRING */
e65f7ae7
MH		 1251 if (!strcmp(parg->type->name, "ustring") ||
1252 code->op == FETCH_OP_UDEREF)
88903c46 1253 code->op = FETCH_OP_ST_USTRING;
b26a124c
MHG		 1254 else if (!strcmp(parg->type->name, "symstr"))
1255 code->op = FETCH_OP_ST_SYMSTR;
88903c46
MH		 1256 else
1257 code->op = FETCH_OP_ST_STRING;
40b53b77 1258 code->size = parg->type->size;
53305928
MH		 1259 parg->dynamic = true;
1260 } else if (code->op == FETCH_OP_DEREF) {
1261 code->op = FETCH_OP_ST_MEM;
1262 code->size = parg->type->size;
e65f7ae7
MH		 1263 } else if (code->op == FETCH_OP_UDEREF) {
1264 code->op = FETCH_OP_ST_UMEM;
1265 code->size = parg->type->size;
53305928
MH		 1266 } else {
1267 code++;
1268 if (code->op != FETCH_OP_NOP) {
1b8b0cd7 1269 trace_probe_log_err(ctx->offset, TOO_MANY_OPS);
53305928
MH		 1270 goto fail;
1271 }
1272 code->op = FETCH_OP_ST_RAW;
1273 code->size = parg->type->size;
1274 }
40b53b77 1275 scode = code;
53305928
MH		 1276 /* Modify operation */
1277 if (t != NULL) {
1278 ret = __parse_bitfield_probe_arg(t, parg->type, &code);
ab105a4f 1279 if (ret) {
1b8b0cd7 1280 trace_probe_log_err(ctx->offset + t - arg, BAD_BITFIELD);
53305928 1281 goto fail;
ab105a4f 1282 }
c440adfb
MHG		 1283 } else if (IS_ENABLED(CONFIG_PROBE_EVENTS_BTF_ARGS) &&
1284 ctx->last_type) {
1285 ret = parse_btf_bitfield(&code, ctx);
1286 if (ret)
1287 goto fail;
8ab83f56 1288 }
fcd9db51 1289 ret = -EINVAL;
40b53b77
MH		 1290 /* Loop(Array) operation */
1291 if (parg->count) {
1292 if (scode->op != FETCH_OP_ST_MEM &&
88903c46
MH		 1293 scode->op != FETCH_OP_ST_STRING &&
1294 scode->op != FETCH_OP_ST_USTRING) {
1b8b0cd7 1295 trace_probe_log_err(ctx->offset + (t ? (t - arg) : 0),
ab105a4f 1296 BAD_STRING);
40b53b77
MH		 1297 goto fail;
1298 }
1299 code++;
1300 if (code->op != FETCH_OP_NOP) {
1b8b0cd7 1301 trace_probe_log_err(ctx->offset, TOO_MANY_OPS);
40b53b77
MH		 1302 goto fail;
1303 }
1304 code->op = FETCH_OP_LP_ARRAY;
1305 code->param = parg->count;
1306 }
53305928
MH		 1307 code++;
1308 code->op = FETCH_OP_END;
1309
fcd9db51 1310 ret = 0;
53305928 1311 /* Shrink down the code buffer */
8623b006 1312 parg->code = kcalloc(code - tmp + 1, sizeof(*code), GFP_KERNEL);
53305928
MH		 1313 if (!parg->code)
1314 ret = -ENOMEM;
1315 else
1316 memcpy(parg->code, tmp, sizeof(*code) * (code - tmp + 1));
1317
1318fail:
a6682814
MH		 1319 if (ret) {
1320 for (code = tmp; code < tmp + FETCH_INSN_MAX; code++)
a42e3c4d
MH		 1321 if (code->op == FETCH_NOP_SYMBOL ||
1322 code->op == FETCH_OP_DATA)
a6682814
MH		 1323 kfree(code->data);
1324 }
53305928 1325 kfree(tmp);
fcd9db51
SRV		 1326out:
1327 kfree(arg);
8ab83f56
SD		 1328
1329 return ret;
1330}
1331
1332/* Return 1 if name is reserved or already used by another argument */
d00bbea9
MH		 1333static int traceprobe_conflict_field_name(const char *name,
1334 struct probe_arg *args, int narg)
8ab83f56
SD		 1335{
1336 int i;
1337
1338 for (i = 0; i < ARRAY_SIZE(reserved_field_names); i++)
1339 if (strcmp(reserved_field_names[i], name) == 0)
1340 return 1;
1341
1342 for (i = 0; i < narg; i++)
1343 if (strcmp(args[i].name, name) == 0)
1344 return 1;
1345
1346 return 0;
1347}
1348
b576e097
MHG		 1349static char *generate_probe_arg_name(const char *arg, int idx)
1350{
1351 char *name = NULL;
1352 const char *end;
1353
1354 /*
1355 * If argument name is omitted, try arg as a name (BTF variable)
1356 * or "argN".
1357 */
1358 if (IS_ENABLED(CONFIG_PROBE_EVENTS_BTF_ARGS)) {
1359 end = strchr(arg, ':');
1360 if (!end)
1361 end = arg + strlen(arg);
1362
1363 name = kmemdup_nul(arg, end - arg, GFP_KERNEL);
1364 if (!name || !is_good_name(name)) {
1365 kfree(name);
1366 name = NULL;
1367 }
1368 }
1369
1370 if (!name)
1371 name = kasprintf(GFP_KERNEL, "arg%d", idx + 1);
1372
1373 return name;
1374}
1375
fcd9db51 1376int traceprobe_parse_probe_arg(struct trace_probe *tp, int i, const char *arg,
1b8b0cd7 1377 struct traceprobe_parse_context *ctx)
d00bbea9
MH		 1378{
1379 struct probe_arg *parg = &tp->args[i];
fcd9db51 1380 const char *body;
d00bbea9
MH		 1381
1382 /* Increment count for freeing args in error case */
1383 tp->nr_args++;
1384
1385 body = strchr(arg, '=');
1386 if (body) {
ab105a4f
MH		 1387 if (body - arg > MAX_ARG_NAME_LEN) {
1388 trace_probe_log_err(0, ARG_NAME_TOO_LONG);
1389 return -EINVAL;
1390 } else if (body == arg) {
1391 trace_probe_log_err(0, NO_ARG_NAME);
b4443c17 1392 return -EINVAL;
ab105a4f 1393 }
d00bbea9
MH		 1394 parg->name = kmemdup_nul(arg, body - arg, GFP_KERNEL);
1395 body++;
1396 } else {
b576e097 1397 parg->name = generate_probe_arg_name(arg, i);
d00bbea9
MH		 1398 body = arg;
1399 }
1400 if (!parg->name)
1401 return -ENOMEM;
1402
1403 if (!is_good_name(parg->name)) {
ab105a4f 1404 trace_probe_log_err(0, BAD_ARG_NAME);
d00bbea9
MH		 1405 return -EINVAL;
1406 }
d00bbea9 1407 if (traceprobe_conflict_field_name(parg->name, tp->args, i)) {
ab105a4f 1408 trace_probe_log_err(0, USED_ARG_NAME);
d00bbea9
MH		 1409 return -EINVAL;
1410 }
1b8b0cd7 1411 ctx->offset = body - arg;
d00bbea9 1412 /* Parse fetch argument */
1b8b0cd7 1413 return traceprobe_parse_probe_arg_body(body, &tp->size, parg, ctx);
d00bbea9
MH		 1414}
1415
8ab83f56
SD		 1416void traceprobe_free_probe_arg(struct probe_arg *arg)
1417{
a6682814
MH		 1418 struct fetch_insn *code = arg->code;
1419
1420 while (code && code->op != FETCH_OP_END) {
a42e3c4d
MH		 1421 if (code->op == FETCH_NOP_SYMBOL ||
1422 code->op == FETCH_OP_DATA)
a6682814
MH		 1423 kfree(code->data);
1424 code++;
1425 }
53305928 1426 kfree(arg->code);
8ab83f56
SD		 1427 kfree(arg->name);
1428 kfree(arg->comm);
40b53b77 1429 kfree(arg->fmt);
8ab83f56
SD		 1430}
1431
18b1e870
MHG		 1432static int argv_has_var_arg(int argc, const char *argv[], int *args_idx,
1433 struct traceprobe_parse_context *ctx)
1434{
1435 int i, found = 0;
1436
1437 for (i = 0; i < argc; i++)
1438 if (str_has_prefix(argv[i], "$arg")) {
1439 trace_probe_log_set_index(i + 2);
1440
1441 if (!tparg_is_function_entry(ctx->flags)) {
1442 trace_probe_log_err(0, NOFENTRY_ARGS);
1443 return -EINVAL;
1444 }
1445
1446 if (isdigit(argv[i][4])) {
1447 found = 1;
1448 continue;
1449 }
1450
1451 if (argv[i][4] != '*') {
1452 trace_probe_log_err(0, BAD_VAR);
1453 return -EINVAL;
1454 }
1455
1456 if (*args_idx >= 0 && *args_idx < argc) {
1457 trace_probe_log_err(0, DOUBLE_ARGS);
1458 return -EINVAL;
1459 }
1460 found = 1;
1461 *args_idx = i;
1462 }
1463
1464 return found;
1465}
1466
1467static int sprint_nth_btf_arg(int idx, const char *type,
1468 char *buf, int bufsize,
1469 struct traceprobe_parse_context *ctx)
1470{
18b1e870
MHG		 1471 const char *name;
1472 int ret;
1473
1474 if (idx >= ctx->nr_params) {
1475 trace_probe_log_err(0, NO_BTFARG);
1476 return -ENOENT;
1477 }
b1d1e904 1478 name = btf_name_by_offset(ctx->btf, ctx->params[idx].name_off);
18b1e870
MHG		 1479 if (!name) {
1480 trace_probe_log_err(0, NO_BTF_ENTRY);
1481 return -ENOENT;
1482 }
1483 ret = snprintf(buf, bufsize, "%s%s", name, type);
1484 if (ret >= bufsize) {
1485 trace_probe_log_err(0, ARGS_2LONG);
1486 return -E2BIG;
1487 }
1488 return ret;
1489}
1490
1491/* Return new_argv which must be freed after use */
1492const char **traceprobe_expand_meta_args(int argc, const char *argv[],
1493 int *new_argc, char *buf, int bufsize,
1494 struct traceprobe_parse_context *ctx)
1495{
1496 const struct btf_param *params = NULL;
1497 int i, j, n, used, ret, args_idx = -1;
1498 const char **new_argv = NULL;
18b1e870
MHG		 1499
1500 ret = argv_has_var_arg(argc, argv, &args_idx, ctx);
1501 if (ret < 0)
1502 return ERR_PTR(ret);
1503
1504 if (!ret) {
1505 *new_argc = argc;
1506 return NULL;
1507 }
1508
d157d769
MHG		 1509 ret = query_btf_context(ctx);
1510 if (ret < 0 || ctx->nr_params == 0) {
18b1e870
MHG		 1511 if (args_idx != -1) {
1512 /* $arg* requires BTF info */
1513 trace_probe_log_err(0, NOSUP_BTFARG);
1514 return (const char **)params;
1515 }
ed5f2978
MHG		 1516 *new_argc = argc;
1517 return NULL;
18b1e870 1518 }
18b1e870
MHG		 1519
1520 if (args_idx >= 0)
1521 *new_argc = argc + ctx->nr_params - 1;
1522 else
1523 *new_argc = argc;
1524
1525 new_argv = kcalloc(*new_argc, sizeof(char *), GFP_KERNEL);
1526 if (!new_argv)
1527 return ERR_PTR(-ENOMEM);
1528
1529 used = 0;
1530 for (i = 0, j = 0; i < argc; i++) {
1531 trace_probe_log_set_index(i + 2);
1532 if (i == args_idx) {
d157d769 1533 for (n = 0; n < ctx->nr_params; n++) {
18b1e870
MHG		 1534 ret = sprint_nth_btf_arg(n, "", buf + used,
1535 bufsize - used, ctx);
1536 if (ret < 0)
1537 goto error;
1538
1539 new_argv[j++] = buf + used;
1540 used += ret + 1;
1541 }
1542 continue;
1543 }
1544
1545 if (str_has_prefix(argv[i], "$arg")) {
1546 char *type = NULL;
1547
1548 n = simple_strtoul(argv[i] + 4, &type, 10);
1549 if (type && !(*type == ':' || *type == '\0')) {
1550 trace_probe_log_err(0, BAD_VAR);
1551 ret = -ENOENT;
1552 goto error;
1553 }
1554 /* Note: $argN starts from $arg1 */
1555 ret = sprint_nth_btf_arg(n - 1, type, buf + used,
1556 bufsize - used, ctx);
1557 if (ret < 0)
1558 goto error;
1559 new_argv[j++] = buf + used;
1560 used += ret + 1;
1561 } else
1562 new_argv[j++] = argv[i];
1563 }
1564
1565 return new_argv;
1566
1567error:
1568 kfree(new_argv);
1569 return ERR_PTR(ret);
1570}
1571
b1d1e904
MHG		 1572void traceprobe_finish_parse(struct traceprobe_parse_context *ctx)
1573{
1574 clear_btf_context(ctx);
1575}
1576
a6682814
MH		 1577int traceprobe_update_arg(struct probe_arg *arg)
1578{
1579 struct fetch_insn *code = arg->code;
1580 long offset;
1581 char *tmp;
1582 char c;
1583 int ret = 0;
1584
1585 while (code && code->op != FETCH_OP_END) {
1586 if (code->op == FETCH_NOP_SYMBOL) {
1587 if (code[1].op != FETCH_OP_IMM)
1588 return -EINVAL;
1589
ee474b81 1590 tmp = strpbrk(code->data, "+-");
a6682814
MH		 1591 if (tmp)
1592 c = *tmp;
1593 ret = traceprobe_split_symbol_offset(code->data,
1594 &offset);
1595 if (ret)
1596 return ret;
1597
1598 code[1].immediate =
1599 (unsigned long)kallsyms_lookup_name(code->data);
1600 if (tmp)
1601 *tmp = c;
1602 if (!code[1].immediate)
1603 return -ENOENT;
1604 code[1].immediate += offset;
1605 }
1606 code++;
1607 }
1608 return 0;
1609}
1610
40b53b77
MH		 1611/* When len=0, we just calculate the needed length */
1612#define LEN_OR_ZERO (len ? len - pos : 0)
5bf652aa 1613static int __set_print_fmt(struct trace_probe *tp, char *buf, int len,
007517a0 1614 enum probe_print_type ptype)
5bf652aa 1615{
40b53b77
MH		 1616 struct probe_arg *parg;
1617 int i, j;
5bf652aa 1618 int pos = 0;
5bf652aa
NK		 1619 const char *fmt, *arg;
1620
007517a0
SRV		 1621 switch (ptype) {
1622 case PROBE_PRINT_NORMAL:
5bf652aa 1623 fmt = "(%lx)";
b61edd57 1624 arg = ", REC->" FIELD_STRING_IP;
007517a0
SRV		 1625 break;
1626 case PROBE_PRINT_RETURN:
5bf652aa 1627 fmt = "(%lx <- %lx)";
b61edd57 1628 arg = ", REC->" FIELD_STRING_FUNC ", REC->" FIELD_STRING_RETIP;
007517a0 1629 break;
7491e2c4 1630 case PROBE_PRINT_EVENT:
b61edd57
SRG		 1631 fmt = "";
1632 arg = "";
7491e2c4 1633 break;
007517a0
SRV		 1634 default:
1635 WARN_ON_ONCE(1);
1636 return 0;
5bf652aa
NK		 1637 }
1638
5bf652aa
NK		 1639 pos += snprintf(buf + pos, LEN_OR_ZERO, "\"%s", fmt);
1640
1641 for (i = 0; i < tp->nr_args; i++) {
40b53b77
MH		 1642 parg = tp->args + i;
1643 pos += snprintf(buf + pos, LEN_OR_ZERO, " %s=", parg->name);
1644 if (parg->count) {
1645 pos += snprintf(buf + pos, LEN_OR_ZERO, "{%s",
1646 parg->type->fmt);
1647 for (j = 1; j < parg->count; j++)
1648 pos += snprintf(buf + pos, LEN_OR_ZERO, ",%s",
1649 parg->type->fmt);
1650 pos += snprintf(buf + pos, LEN_OR_ZERO, "}");
1651 } else
1652 pos += snprintf(buf + pos, LEN_OR_ZERO, "%s",
1653 parg->type->fmt);
5bf652aa
NK		 1654 }
1655
b61edd57 1656 pos += snprintf(buf + pos, LEN_OR_ZERO, "\"%s", arg);
5bf652aa
NK		 1657
1658 for (i = 0; i < tp->nr_args; i++) {
40b53b77
MH		 1659 parg = tp->args + i;
1660 if (parg->count) {
b26a124c 1661 if (parg->type->is_string)
40b53b77
MH		 1662 fmt = ", __get_str(%s[%d])";
1663 else
1664 fmt = ", REC->%s[%d]";
1665 for (j = 0; j < parg->count; j++)
1666 pos += snprintf(buf + pos, LEN_OR_ZERO,
1667 fmt, parg->name, j);
1668 } else {
b26a124c 1669 if (parg->type->is_string)
40b53b77
MH		 1670 fmt = ", __get_str(%s)";
1671 else
1672 fmt = ", REC->%s";
5bf652aa 1673 pos += snprintf(buf + pos, LEN_OR_ZERO,
40b53b77
MH		 1674 fmt, parg->name);
1675 }
5bf652aa
NK		 1676 }
1677
5bf652aa
NK		 1678 /* return the length of print_fmt */
1679 return pos;
1680}
40b53b77 1681#undef LEN_OR_ZERO
5bf652aa 1682
007517a0 1683int traceprobe_set_print_fmt(struct trace_probe *tp, enum probe_print_type ptype)
5bf652aa 1684{
e3dc9f89 1685 struct trace_event_call *call = trace_probe_event_call(tp);
5bf652aa
NK		 1686 int len;
1687 char *print_fmt;
1688
1689 /* First: called with 0 length to calculate the needed length */
007517a0 1690 len = __set_print_fmt(tp, NULL, 0, ptype);
5bf652aa
NK		 1691 print_fmt = kmalloc(len + 1, GFP_KERNEL);
1692 if (!print_fmt)
1693 return -ENOMEM;
1694
1695 /* Second: actually write the @print_fmt */
007517a0 1696 __set_print_fmt(tp, print_fmt, len + 1, ptype);
e3dc9f89 1697 call->print_fmt = print_fmt;
5bf652aa
NK		 1698
1699 return 0;
1700}
eeb07b06
MH		 1701
1702int traceprobe_define_arg_fields(struct trace_event_call *event_call,
1703 size_t offset, struct trace_probe *tp)
1704{
1705 int ret, i;
1706
1707 /* Set argument names as fields */
1708 for (i = 0; i < tp->nr_args; i++) {
1709 struct probe_arg *parg = &tp->args[i];
40b53b77
MH		 1710 const char *fmt = parg->type->fmttype;
1711 int size = parg->type->size;
1712
1713 if (parg->fmt)
1714 fmt = parg->fmt;
1715 if (parg->count)
1716 size *= parg->count;
1717 ret = trace_define_field(event_call, fmt, parg->name,
1718 offset + parg->offset, size,
eeb07b06
MH		 1719 parg->type->is_signed,
1720 FILTER_OTHER);
1721 if (ret)
1722 return ret;
1723 }
1724 return 0;
1725}
455b2899 1726
ca89bc07
MH		 1727static void trace_probe_event_free(struct trace_probe_event *tpe)
1728{
1729 kfree(tpe->class.system);
1730 kfree(tpe->call.name);
1731 kfree(tpe->call.print_fmt);
1732 kfree(tpe);
1733}
1734
1735int trace_probe_append(struct trace_probe *tp, struct trace_probe *to)
1736{
1737 if (trace_probe_has_sibling(tp))
1738 return -EBUSY;
1739
1740 list_del_init(&tp->list);
1741 trace_probe_event_free(tp->event);
1742
1743 tp->event = to->event;
1744 list_add_tail(&tp->list, trace_probe_probe_list(to));
1745
1746 return 0;
1747}
1748
1749void trace_probe_unlink(struct trace_probe *tp)
1750{
1751 list_del_init(&tp->list);
1752 if (list_empty(trace_probe_probe_list(tp)))
1753 trace_probe_event_free(tp->event);
1754 tp->event = NULL;
1755}
455b2899
MH		 1756
1757void trace_probe_cleanup(struct trace_probe *tp)
1758{
1759 int i;
1760
1761 for (i = 0; i < tp->nr_args; i++)
1762 traceprobe_free_probe_arg(&tp->args[i]);
1763
ca89bc07
MH		 1764 if (tp->event)
1765 trace_probe_unlink(tp);
455b2899
MH		 1766}
1767
1768int trace_probe_init(struct trace_probe *tp, const char *event,
b61387cb 1769 const char *group, bool alloc_filter)
455b2899 1770{
60d53e2c 1771 struct trace_event_call *call;
b61387cb 1772 size_t size = sizeof(struct trace_probe_event);
60d53e2c 1773 int ret = 0;
e3dc9f89 1774
455b2899
MH		 1775 if (!event || !group)
1776 return -EINVAL;
1777
b61387cb
MH		 1778 if (alloc_filter)
1779 size += sizeof(struct trace_uprobe_filter);
1780
1781 tp->event = kzalloc(size, GFP_KERNEL);
60d53e2c 1782 if (!tp->event)
455b2899
MH		 1783 return -ENOMEM;
1784
d59fae6f
MH		 1785 INIT_LIST_HEAD(&tp->event->files);
1786 INIT_LIST_HEAD(&tp->event->class.fields);
1787 INIT_LIST_HEAD(&tp->event->probes);
1788 INIT_LIST_HEAD(&tp->list);
fc9d276f 1789 list_add(&tp->list, &tp->event->probes);
d59fae6f 1790
60d53e2c
MH		 1791 call = trace_probe_event_call(tp);
1792 call->class = &tp->event->class;
1793 call->name = kstrdup(event, GFP_KERNEL);
1794 if (!call->name) {
1795 ret = -ENOMEM;
1796 goto error;
1797 }
1798
1799 tp->event->class.system = kstrdup(group, GFP_KERNEL);
1800 if (!tp->event->class.system) {
1801 ret = -ENOMEM;
1802 goto error;
455b2899 1803 }
455b2899
MH		 1804
1805 return 0;
60d53e2c
MH		 1806
1807error:
1808 trace_probe_cleanup(tp);
1809 return ret;
455b2899 1810}
46e5376d 1811
8e242060
MH		 1812static struct trace_event_call *
1813find_trace_event_call(const char *system, const char *event_name)
1814{
1815 struct trace_event_call *tp_event;
1816 const char *name;
1817
1818 list_for_each_entry(tp_event, &ftrace_events, list) {
1819 if (!tp_event->class->system ||
1820 strcmp(system, tp_event->class->system))
1821 continue;
1822 name = trace_event_name(tp_event);
1823 if (!name || strcmp(event_name, name))
1824 continue;
1825 return tp_event;
1826 }
1827
1828 return NULL;
1829}
1830
46e5376d
MH		 1831int trace_probe_register_event_call(struct trace_probe *tp)
1832{
e3dc9f89 1833 struct trace_event_call *call = trace_probe_event_call(tp);
46e5376d
MH		 1834 int ret;
1835
8e242060
MH		 1836 lockdep_assert_held(&event_mutex);
1837
1838 if (find_trace_event_call(trace_probe_group_name(tp),
1839 trace_probe_name(tp)))
1840 return -EEXIST;
1841
46e5376d
MH		 1842 ret = register_trace_event(&call->event);
1843 if (!ret)
1844 return -ENODEV;
1845
1846 ret = trace_add_event_call(call);
1847 if (ret)
1848 unregister_trace_event(&call->event);
1849
1850 return ret;
1851}
b5f935ee
MH		 1852
1853int trace_probe_add_file(struct trace_probe *tp, struct trace_event_file *file)
1854{
1855 struct event_file_link *link;
1856
1857 link = kmalloc(sizeof(*link), GFP_KERNEL);
1858 if (!link)
1859 return -ENOMEM;
1860
1861 link->file = file;
1862 INIT_LIST_HEAD(&link->list);
60d53e2c 1863 list_add_tail_rcu(&link->list, &tp->event->files);
747774d6 1864 trace_probe_set_flag(tp, TP_FLAG_TRACE);
b5f935ee
MH		 1865 return 0;
1866}
1867
1868struct event_file_link *trace_probe_get_file_link(struct trace_probe *tp,
1869 struct trace_event_file *file)
1870{
1871 struct event_file_link *link;
1872
1873 trace_probe_for_each_link(link, tp) {
1874 if (link->file == file)
1875 return link;
1876 }
1877
1878 return NULL;
1879}
1880
1881int trace_probe_remove_file(struct trace_probe *tp,
1882 struct trace_event_file *file)
1883{
1884 struct event_file_link *link;
1885
1886 link = trace_probe_get_file_link(tp, file);
1887 if (!link)
1888 return -ENOENT;
1889
1890 list_del_rcu(&link->list);
cae16f2c 1891 kvfree_rcu_mightsleep(link);
b5f935ee 1892
60d53e2c 1893 if (list_empty(&tp->event->files))
747774d6 1894 trace_probe_clear_flag(tp, TP_FLAG_TRACE);
b5f935ee
MH		 1895
1896 return 0;
1897}
ca89bc07
MH		 1898
1899/*
1900 * Return the smallest index of different type argument (start from 1).
1901 * If all argument types and name are same, return 0.
1902 */
1903int trace_probe_compare_arg_type(struct trace_probe *a, struct trace_probe *b)
1904{
1905 int i;
1906
d2aea95a
MH		 1907 /* In case of more arguments */
1908 if (a->nr_args < b->nr_args)
1909 return a->nr_args + 1;
1910 if (a->nr_args > b->nr_args)
1911 return b->nr_args + 1;
1912
ca89bc07
MH		 1913 for (i = 0; i < a->nr_args; i++) {
1914 if ((b->nr_args <= i) ||
1915 ((a->args[i].type != b->args[i].type) ||
1916 (a->args[i].count != b->args[i].count) ||
1917 strcmp(a->args[i].name, b->args[i].name)))
1918 return i + 1;
1919 }
1920
1921 return 0;
1922}
eb5bf813
MH		 1923
1924bool trace_probe_match_command_args(struct trace_probe *tp,
1925 int argc, const char **argv)
1926{
1927 char buf[MAX_ARGSTR_LEN + 1];
1928 int i;
1929
1930 if (tp->nr_args < argc)
1931 return false;
1932
1933 for (i = 0; i < argc; i++) {
1934 snprintf(buf, sizeof(buf), "%s=%s",
1935 tp->args[i].name, tp->args[i].comm);
1936 if (strcmp(buf, argv[i]))
1937 return false;
1938 }
1939 return true;
1940}
d262271d
MH		 1941
1942int trace_probe_create(const char *raw_command, int (*createfn)(int, const char **))
1943{
1944 int argc = 0, ret = 0;
1945 char **argv;
1946
1947 argv = argv_split(GFP_KERNEL, raw_command, &argc);
1948 if (!argv)
1949 return -ENOMEM;
1950
1951 if (argc)
1952 ret = createfn(argc, (const char **)argv);
1953
1954 argv_free(argv);
1955
1956 return ret;
1957}
196b6389
SC		 1958
1959int trace_probe_print_args(struct trace_seq *s, struct probe_arg *args, int nr_args,
1960 u8 *data, void *field)
1961{
1962 void *p;
1963 int i, j;
1964
1965 for (i = 0; i < nr_args; i++) {
1966 struct probe_arg *a = args + i;
1967
1968 trace_seq_printf(s, " %s=", a->name);
1969 if (likely(!a->count)) {
1970 if (!a->type->print(s, data + a->offset, field))
1971 return -ENOMEM;
1972 continue;
1973 }
1974 trace_seq_putc(s, '{');
1975 p = data + a->offset;
1976 for (j = 0; j < a->count; j++) {
1977 if (!a->type->print(s, p, field))
1978 return -ENOMEM;
1979 trace_seq_putc(s, j == a->count - 1 ? '}' : ',');
1980 p += a->type->size;
1981 }
1982 }
1983 return 0;
1984}
Linux 6.x block layer and io_uring tree(s)