1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Common code for probe-based Dynamic events.
4 *
5 * This code was copied from kernel/trace/trace_kprobe.c written by
6 * Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
7 *
8 * Updates to make this generic:
9 * Copyright (C) IBM Corporation, 2010-2011
10 * Author: Srikar Dronamraju
11 */
12#define pr_fmt(fmt) "trace_probe: " fmt
13
14#include <linux/bpf.h>
15#include <linux/fs.h>
16
17#include "trace_btf.h"
18#include "trace_probe.h"
19
20#undef C
21#define C(a, b) b
22
23static const char *trace_probe_err_text[] = { ERRORS };
24
25static const char *reserved_field_names[] = {
26 "common_type",
27 "common_flags",
28 "common_preempt_count",
29 "common_pid",
30 "common_tgid",
31 FIELD_STRING_IP,
32 FIELD_STRING_RETIP,
33 FIELD_STRING_FUNC,
34};
35
36/* Printing in basic type function template */
37#define DEFINE_BASIC_PRINT_TYPE_FUNC(tname, type, fmt) \
38int PRINT_TYPE_FUNC_NAME(tname)(struct trace_seq *s, void *data, void *ent)\
39{ \
40 trace_seq_printf(s, fmt, *(type *)data); \
41 return !trace_seq_has_overflowed(s); \
42} \
43const char PRINT_TYPE_FMT_NAME(tname)[] = fmt;
44
45DEFINE_BASIC_PRINT_TYPE_FUNC(u8, u8, "%u")
46DEFINE_BASIC_PRINT_TYPE_FUNC(u16, u16, "%u")
47DEFINE_BASIC_PRINT_TYPE_FUNC(u32, u32, "%u")
48DEFINE_BASIC_PRINT_TYPE_FUNC(u64, u64, "%Lu")
49DEFINE_BASIC_PRINT_TYPE_FUNC(s8, s8, "%d")
50DEFINE_BASIC_PRINT_TYPE_FUNC(s16, s16, "%d")
51DEFINE_BASIC_PRINT_TYPE_FUNC(s32, s32, "%d")
52DEFINE_BASIC_PRINT_TYPE_FUNC(s64, s64, "%Ld")
53DEFINE_BASIC_PRINT_TYPE_FUNC(x8, u8, "0x%x")
54DEFINE_BASIC_PRINT_TYPE_FUNC(x16, u16, "0x%x")
55DEFINE_BASIC_PRINT_TYPE_FUNC(x32, u32, "0x%x")
56DEFINE_BASIC_PRINT_TYPE_FUNC(x64, u64, "0x%Lx")
57DEFINE_BASIC_PRINT_TYPE_FUNC(char, u8, "'%c'")
58
59int PRINT_TYPE_FUNC_NAME(symbol)(struct trace_seq *s, void *data, void *ent)
60{
61 trace_seq_printf(s, fmt: "%pS", (void *)*(unsigned long *)data);
62 return !trace_seq_has_overflowed(s);
63}
64const char PRINT_TYPE_FMT_NAME(symbol)[] = "%pS";
65
66/* Print type function for string type */
67int PRINT_TYPE_FUNC_NAME(string)(struct trace_seq *s, void *data, void *ent)
68{
69 int len = *(u32 *)data >> 16;
70
71 if (!len)
72 trace_seq_puts(s, FAULT_STRING);
73 else
74 trace_seq_printf(s, fmt: "\"%s\"",
75 (const char *)get_loc_data(dl: data, ent));
76 return !trace_seq_has_overflowed(s);
77}
78
79const char PRINT_TYPE_FMT_NAME(string)[] = "\\\"%s\\\"";
80
81/* Fetch type information table */
82static const struct fetch_type probe_fetch_types[] = {
83 /* Special types */
84 __ASSIGN_FETCH_TYPE("string", string, string, sizeof(u32), 1, 1,
85 "__data_loc char[]"),
86 __ASSIGN_FETCH_TYPE("ustring", string, string, sizeof(u32), 1, 1,
87 "__data_loc char[]"),
88 __ASSIGN_FETCH_TYPE("symstr", string, string, sizeof(u32), 1, 1,
89 "__data_loc char[]"),
90 /* Basic types */
91 ASSIGN_FETCH_TYPE(u8, u8, 0),
92 ASSIGN_FETCH_TYPE(u16, u16, 0),
93 ASSIGN_FETCH_TYPE(u32, u32, 0),
94 ASSIGN_FETCH_TYPE(u64, u64, 0),
95 ASSIGN_FETCH_TYPE(s8, u8, 1),
96 ASSIGN_FETCH_TYPE(s16, u16, 1),
97 ASSIGN_FETCH_TYPE(s32, u32, 1),
98 ASSIGN_FETCH_TYPE(s64, u64, 1),
99 ASSIGN_FETCH_TYPE_ALIAS(x8, u8, u8, 0),
100 ASSIGN_FETCH_TYPE_ALIAS(x16, u16, u16, 0),
101 ASSIGN_FETCH_TYPE_ALIAS(x32, u32, u32, 0),
102 ASSIGN_FETCH_TYPE_ALIAS(x64, u64, u64, 0),
103 ASSIGN_FETCH_TYPE_ALIAS(char, u8, u8, 0),
104 ASSIGN_FETCH_TYPE_ALIAS(symbol, ADDR_FETCH_TYPE, ADDR_FETCH_TYPE, 0),
105
106 ASSIGN_FETCH_TYPE_END
107};
108
109static const struct fetch_type *find_fetch_type(const char *type, unsigned long flags)
110{
111 int i;
112
113 /* Reject the symbol/symstr for uprobes */
114 if (type && (flags & TPARG_FL_USER) &&
115 (!strcmp(type, "symbol") || !strcmp(type, "symstr")))
116 return NULL;
117
118 if (!type)
119 type = DEFAULT_FETCH_TYPE_STR;
120
121 /* Special case: bitfield */
122 if (*type == 'b') {
123 unsigned long bs;
124
125 type = strchr(type, '/');
126 if (!type)
127 goto fail;
128
129 type++;
130 if (kstrtoul(s: type, base: 0, res: &bs))
131 goto fail;
132
133 switch (bs) {
134 case 8:
135 return find_fetch_type(type: "u8", flags);
136 case 16:
137 return find_fetch_type(type: "u16", flags);
138 case 32:
139 return find_fetch_type(type: "u32", flags);
140 case 64:
141 return find_fetch_type(type: "u64", flags);
142 default:
143 goto fail;
144 }
145 }
146
147 for (i = 0; probe_fetch_types[i].name; i++) {
148 if (strcmp(type, probe_fetch_types[i].name) == 0)
149 return &probe_fetch_types[i];
150 }
151
152fail:
153 return NULL;
154}
155
156static struct trace_probe_log trace_probe_log;
157extern struct mutex dyn_event_ops_mutex;
158
159void trace_probe_log_init(const char *subsystem, int argc, const char **argv)
160{
161 lockdep_assert_held(&dyn_event_ops_mutex);
162
163 trace_probe_log.subsystem = subsystem;
164 trace_probe_log.argc = argc;
165 trace_probe_log.argv = argv;
166 trace_probe_log.index = 0;
167}
168
169void trace_probe_log_clear(void)
170{
171 lockdep_assert_held(&dyn_event_ops_mutex);
172
173 memset(s: &trace_probe_log, c: 0, n: sizeof(trace_probe_log));
174}
175
176void trace_probe_log_set_index(int index)
177{
178 lockdep_assert_held(&dyn_event_ops_mutex);
179
180 trace_probe_log.index = index;
181}
182
183void __trace_probe_log_err(int offset, int err_type)
184{
185 char *command, *p;
186 int i, len = 0, pos = 0;
187
188 lockdep_assert_held(&dyn_event_ops_mutex);
189
190 if (!trace_probe_log.argv)
191 return;
192
193 /* Recalculate the length and allocate buffer */
194 for (i = 0; i < trace_probe_log.argc; i++) {
195 if (i == trace_probe_log.index)
196 pos = len;
197 len += strlen(trace_probe_log.argv[i]) + 1;
198 }
199 command = kzalloc(len, GFP_KERNEL);
200 if (!command)
201 return;
202
203 if (trace_probe_log.index >= trace_probe_log.argc) {
204 /**
205 * Set the error position is next to the last arg + space.
206 * Note that len includes the terminal null and the cursor
207 * appears at pos + 1.
208 */
209 pos = len;
210 offset = 0;
211 }
212
213 /* And make a command string from argv array */
214 p = command;
215 for (i = 0; i < trace_probe_log.argc; i++) {
216 len = strlen(trace_probe_log.argv[i]);
217 strcpy(p, trace_probe_log.argv[i]);
218 p[len] = ' ';
219 p += len + 1;
220 }
221 *(p - 1) = '\0';
222
223 tracing_log_err(NULL, loc: trace_probe_log.subsystem, cmd: command,
224 errs: trace_probe_err_text, type: err_type, pos: pos + offset);
225
226 kfree(objp: command);
227}
228
229/* Split symbol and offset. */
230int traceprobe_split_symbol_offset(char *symbol, long *offset)
231{
232 char *tmp;
233 int ret;
234
235 if (!offset)
236 return -EINVAL;
237
238 tmp = strpbrk(symbol, "+-");
239 if (tmp) {
240 ret = kstrtol(s: tmp, base: 0, res: offset);
241 if (ret)
242 return ret;
243 *tmp = '\0';
244 } else
245 *offset = 0;
246
247 return 0;
248}
249
250/**
251 * traceprobe_parse_event_name() - Parse a string into group and event names
252 * @pevent: A pointer to the string to be parsed.
253 * @pgroup: A pointer to the group name.
254 * @buf: A buffer to store the parsed group name.
255 * @offset: The offset of the string in the original user command, for logging.
256 *
257 * This parses a string with the format `[GROUP/][EVENT]` or `[GROUP.][EVENT]`
258 * (either GROUP or EVENT or both must be specified).
259 * Since the parsed group name is stored in @buf, the caller must ensure @buf
260 * is at least MAX_EVENT_NAME_LEN bytes.
261 *
262 * Return: 0 on success, or -EINVAL on failure.
263 *
264 * If success, *@pevent is updated to point to the event name part of the
265 * original string, or NULL if there is no event name.
266 * Also, *@pgroup is updated to point to the parsed group which is stored
267 * in @buf, or NULL if there is no group name.
268 */
269int traceprobe_parse_event_name(const char **pevent, const char **pgroup,
270 char *buf, int offset)
271{
272 const char *slash, *event = *pevent;
273 int len;
274
275 slash = strchr(event, '/');
276 if (!slash)
277 slash = strchr(event, '.');
278
279 if (slash) {
280 if (slash == event) {
281 trace_probe_log_err(offset, NO_GROUP_NAME);
282 return -EINVAL;
283 }
284 if (slash - event + 1 > MAX_EVENT_NAME_LEN) {
285 trace_probe_log_err(offset, GROUP_TOO_LONG);
286 return -EINVAL;
287 }
288 strscpy(buf, event, slash - event + 1);
289 if (!is_good_system_name(name: buf)) {
290 trace_probe_log_err(offset, BAD_GROUP_NAME);
291 return -EINVAL;
292 }
293 *pgroup = buf;
294 *pevent = slash + 1;
295 offset += slash - event + 1;
296 event = *pevent;
297 }
298 len = strlen(event);
299 if (len == 0) {
300 if (slash) {
301 *pevent = NULL;
302 return 0;
303 }
304 trace_probe_log_err(offset, NO_EVENT_NAME);
305 return -EINVAL;
306 } else if (len >= MAX_EVENT_NAME_LEN) {
307 trace_probe_log_err(offset, EVENT_TOO_LONG);
308 return -EINVAL;
309 }
310 if (!is_good_name(name: event)) {
311 trace_probe_log_err(offset, BAD_EVENT_NAME);
312 return -EINVAL;
313 }
314 return 0;
315}
316
317static int parse_trace_event_arg(char *arg, struct fetch_insn *code,
318 struct traceprobe_parse_context *ctx)
319{
320 struct ftrace_event_field *field;
321 struct list_head *head;
322
323 head = trace_get_fields(event_call: ctx->event);
324 list_for_each_entry(field, head, link) {
325 if (!strcmp(arg, field->name)) {
326 code->op = FETCH_OP_TP_ARG;
327 code->data = field;
328 return 0;
329 }
330 }
331 return -ENOENT;
332}
333
334#ifdef CONFIG_PROBE_EVENTS_BTF_ARGS
335
336static u32 btf_type_int(const struct btf_type *t)
337{
338 return *(u32 *)(t + 1);
339}
340
341static bool btf_type_is_char_ptr(struct btf *btf, const struct btf_type *type)
342{
343 const struct btf_type *real_type;
344 u32 intdata;
345 s32 tid;
346
347 real_type = btf_type_skip_modifiers(btf, type->type, &tid);
348 if (!real_type)
349 return false;
350
351 if (BTF_INFO_KIND(real_type->info) != BTF_KIND_INT)
352 return false;
353
354 intdata = btf_type_int(real_type);
355 return !(BTF_INT_ENCODING(intdata) & BTF_INT_SIGNED)
356 && BTF_INT_BITS(intdata) == 8;
357}
358
359static bool btf_type_is_char_array(struct btf *btf, const struct btf_type *type)
360{
361 const struct btf_type *real_type;
362 const struct btf_array *array;
363 u32 intdata;
364 s32 tid;
365
366 if (BTF_INFO_KIND(type->info) != BTF_KIND_ARRAY)
367 return false;
368
369 array = (const struct btf_array *)(type + 1);
370
371 real_type = btf_type_skip_modifiers(btf, array->type, &tid);
372
373 intdata = btf_type_int(real_type);
374 return !(BTF_INT_ENCODING(intdata) & BTF_INT_SIGNED)
375 && BTF_INT_BITS(intdata) == 8;
376}
377
378static int check_prepare_btf_string_fetch(char *typename,
379 struct fetch_insn **pcode,
380 struct traceprobe_parse_context *ctx)
381{
382 struct btf *btf = ctx->btf;
383
384 if (!btf || !ctx->last_type)
385 return 0;
386
387 /* char [] does not need any change. */
388 if (btf_type_is_char_array(btf, ctx->last_type))
389 return 0;
390
391 /* char * requires dereference the pointer. */
392 if (btf_type_is_char_ptr(btf, ctx->last_type)) {
393 struct fetch_insn *code = *pcode + 1;
394
395 if (code->op == FETCH_OP_END) {
396 trace_probe_log_err(ctx->offset, TOO_MANY_OPS);
397 return -E2BIG;
398 }
399 if (typename[0] == 'u')
400 code->op = FETCH_OP_UDEREF;
401 else
402 code->op = FETCH_OP_DEREF;
403 code->offset = 0;
404 *pcode = code;
405 return 0;
406 }
407 /* Other types are not available for string */
408 trace_probe_log_err(ctx->offset, BAD_TYPE4STR);
409 return -EINVAL;
410}
411
412static const char *fetch_type_from_btf_type(struct btf *btf,
413 const struct btf_type *type,
414 struct traceprobe_parse_context *ctx)
415{
416 u32 intdata;
417
418 /* TODO: const char * could be converted as a string */
419 switch (BTF_INFO_KIND(type->info)) {
420 case BTF_KIND_ENUM:
421 /* enum is "int", so convert to "s32" */
422 return "s32";
423 case BTF_KIND_ENUM64:
424 return "s64";
425 case BTF_KIND_PTR:
426 /* pointer will be converted to "x??" */
427 if (IS_ENABLED(CONFIG_64BIT))
428 return "x64";
429 else
430 return "x32";
431 case BTF_KIND_INT:
432 intdata = btf_type_int(type);
433 if (BTF_INT_ENCODING(intdata) & BTF_INT_SIGNED) {
434 switch (BTF_INT_BITS(intdata)) {
435 case 8:
436 return "s8";
437 case 16:
438 return "s16";
439 case 32:
440 return "s32";
441 case 64:
442 return "s64";
443 }
444 } else { /* unsigned */
445 switch (BTF_INT_BITS(intdata)) {
446 case 8:
447 return "u8";
448 case 16:
449 return "u16";
450 case 32:
451 return "u32";
452 case 64:
453 return "u64";
454 }
455 /* bitfield, size is encoded in the type */
456 ctx->last_bitsize = BTF_INT_BITS(intdata);
457 ctx->last_bitoffs += BTF_INT_OFFSET(intdata);
458 return "u64";
459 }
460 }
461 /* TODO: support other types */
462
463 return NULL;
464}
465
466static int query_btf_context(struct traceprobe_parse_context *ctx)
467{
468 const struct btf_param *param;
469 const struct btf_type *type;
470 struct btf *btf;
471 s32 nr;
472
473 if (ctx->btf)
474 return 0;
475
476 if (!ctx->funcname)
477 return -EINVAL;
478
479 type = btf_find_func_proto(ctx->funcname, &btf);
480 if (!type)
481 return -ENOENT;
482
483 ctx->btf = btf;
484 ctx->proto = type;
485
486 /* ctx->params is optional, since func(void) will not have params. */
487 nr = 0;
488 param = btf_get_func_param(type, &nr);
489 if (!IS_ERR_OR_NULL(param)) {
490 /* Hide the first 'data' argument of tracepoint */
491 if (ctx->flags & TPARG_FL_TPOINT) {
492 nr--;
493 param++;
494 }
495 }
496
497 if (nr > 0) {
498 ctx->nr_params = nr;
499 ctx->params = param;
500 } else {
501 ctx->nr_params = 0;
502 ctx->params = NULL;
503 }
504
505 return 0;
506}
507
508static void clear_btf_context(struct traceprobe_parse_context *ctx)
509{
510 if (ctx->btf) {
511 btf_put(ctx->btf);
512 ctx->btf = NULL;
513 ctx->proto = NULL;
514 ctx->params = NULL;
515 ctx->nr_params = 0;
516 }
517}
518
519/* Return 1 if the field separater is arrow operator ('->') */
520static int split_next_field(char *varname, char **next_field,
521 struct traceprobe_parse_context *ctx)
522{
523 char *field;
524 int ret = 0;
525
526 field = strpbrk(varname, ".-");
527 if (field) {
528 if (field[0] == '-' && field[1] == '>') {
529 field[0] = '\0';
530 field += 2;
531 ret = 1;
532 } else if (field[0] == '.') {
533 field[0] = '\0';
534 field += 1;
535 } else {
536 trace_probe_log_err(ctx->offset + field - varname, BAD_HYPHEN);
537 return -EINVAL;
538 }
539 *next_field = field;
540 }
541
542 return ret;
543}
544
545/*
546 * Parse the field of data structure. The @type must be a pointer type
547 * pointing the target data structure type.
548 */
549static int parse_btf_field(char *fieldname, const struct btf_type *type,
550 struct fetch_insn **pcode, struct fetch_insn *end,
551 struct traceprobe_parse_context *ctx)
552{
553 struct fetch_insn *code = *pcode;
554 const struct btf_member *field;
555 u32 bitoffs, anon_offs;
556 char *next;
557 int is_ptr;
558 s32 tid;
559
560 do {
561 /* Outer loop for solving arrow operator ('->') */
562 if (BTF_INFO_KIND(type->info) != BTF_KIND_PTR) {
563 trace_probe_log_err(ctx->offset, NO_PTR_STRCT);
564 return -EINVAL;
565 }
566 /* Convert a struct pointer type to a struct type */
567 type = btf_type_skip_modifiers(ctx->btf, type->type, &tid);
568 if (!type) {
569 trace_probe_log_err(ctx->offset, BAD_BTF_TID);
570 return -EINVAL;
571 }
572
573 bitoffs = 0;
574 do {
575 /* Inner loop for solving dot operator ('.') */
576 next = NULL;
577 is_ptr = split_next_field(fieldname, &next, ctx);
578 if (is_ptr < 0)
579 return is_ptr;
580
581 anon_offs = 0;
582 field = btf_find_struct_member(ctx->btf, type, fieldname,
583 &anon_offs);
584 if (IS_ERR(field)) {
585 trace_probe_log_err(ctx->offset, BAD_BTF_TID);
586 return PTR_ERR(field);
587 }
588 if (!field) {
589 trace_probe_log_err(ctx->offset, NO_BTF_FIELD);
590 return -ENOENT;
591 }
592 /* Add anonymous structure/union offset */
593 bitoffs += anon_offs;
594
595 /* Accumulate the bit-offsets of the dot-connected fields */
596 if (btf_type_kflag(type)) {
597 bitoffs += BTF_MEMBER_BIT_OFFSET(field->offset);
598 ctx->last_bitsize = BTF_MEMBER_BITFIELD_SIZE(field->offset);
599 } else {
600 bitoffs += field->offset;
601 ctx->last_bitsize = 0;
602 }
603
604 type = btf_type_skip_modifiers(ctx->btf, field->type, &tid);
605 if (!type) {
606 trace_probe_log_err(ctx->offset, BAD_BTF_TID);
607 return -EINVAL;
608 }
609
610 ctx->offset += next - fieldname;
611 fieldname = next;
612 } while (!is_ptr && fieldname);
613
614 if (++code == end) {
615 trace_probe_log_err(ctx->offset, TOO_MANY_OPS);
616 return -EINVAL;
617 }
618 code->op = FETCH_OP_DEREF; /* TODO: user deref support */
619 code->offset = bitoffs / 8;
620 *pcode = code;
621
622 ctx->last_bitoffs = bitoffs % 8;
623 ctx->last_type = type;
624 } while (fieldname);
625
626 return 0;
627}
628
629static int __store_entry_arg(struct trace_probe *tp, int argnum);
630
631static int parse_btf_arg(char *varname,
632 struct fetch_insn **pcode, struct fetch_insn *end,
633 struct traceprobe_parse_context *ctx)
634{
635 struct fetch_insn *code = *pcode;
636 const struct btf_param *params;
637 const struct btf_type *type;
638 char *field = NULL;
639 int i, is_ptr, ret;
640 u32 tid;
641
642 if (WARN_ON_ONCE(!ctx->funcname))
643 return -EINVAL;
644
645 is_ptr = split_next_field(varname, &field, ctx);
646 if (is_ptr < 0)
647 return is_ptr;
648 if (!is_ptr && field) {
649 /* dot-connected field on an argument is not supported. */
650 trace_probe_log_err(ctx->offset + field - varname,
651 NOSUP_DAT_ARG);
652 return -EOPNOTSUPP;
653 }
654
655 if (ctx->flags & TPARG_FL_RETURN && !strcmp(varname, "$retval")) {
656 code->op = FETCH_OP_RETVAL;
657 /* Check whether the function return type is not void */
658 if (query_btf_context(ctx) == 0) {
659 if (ctx->proto->type == 0) {
660 trace_probe_log_err(ctx->offset, NO_RETVAL);
661 return -ENOENT;
662 }
663 tid = ctx->proto->type;
664 goto found;
665 }
666 if (field) {
667 trace_probe_log_err(ctx->offset + field - varname,
668 NO_BTF_ENTRY);
669 return -ENOENT;
670 }
671 return 0;
672 }
673
674 if (!ctx->btf) {
675 ret = query_btf_context(ctx);
676 if (ret < 0 || ctx->nr_params == 0) {
677 trace_probe_log_err(ctx->offset, NO_BTF_ENTRY);
678 return -ENOENT;
679 }
680 }
681 params = ctx->params;
682
683 for (i = 0; i < ctx->nr_params; i++) {
684 const char *name = btf_name_by_offset(ctx->btf, params[i].name_off);
685
686 if (name && !strcmp(name, varname)) {
687 if (tparg_is_function_entry(ctx->flags)) {
688 code->op = FETCH_OP_ARG;
689 if (ctx->flags & TPARG_FL_TPOINT)
690 code->param = i + 1;
691 else
692 code->param = i;
693 } else if (tparg_is_function_return(ctx->flags)) {
694 code->op = FETCH_OP_EDATA;
695 ret = __store_entry_arg(ctx->tp, i);
696 if (ret < 0) {
697 /* internal error */
698 return ret;
699 }
700 code->offset = ret;
701 }
702 tid = params[i].type;
703 goto found;
704 }
705 }
706 trace_probe_log_err(ctx->offset, NO_BTFARG);
707 return -ENOENT;
708
709found:
710 type = btf_type_skip_modifiers(ctx->btf, tid, &tid);
711 if (!type) {
712 trace_probe_log_err(ctx->offset, BAD_BTF_TID);
713 return -EINVAL;
714 }
715 /* Initialize the last type information */
716 ctx->last_type = type;
717 ctx->last_bitoffs = 0;
718 ctx->last_bitsize = 0;
719 if (field) {
720 ctx->offset += field - varname;
721 return parse_btf_field(field, type, pcode, end, ctx);
722 }
723 return 0;
724}
725
726static const struct fetch_type *find_fetch_type_from_btf_type(
727 struct traceprobe_parse_context *ctx)
728{
729 struct btf *btf = ctx->btf;
730 const char *typestr = NULL;
731
732 if (btf && ctx->last_type)
733 typestr = fetch_type_from_btf_type(btf, ctx->last_type, ctx);
734
735 return find_fetch_type(typestr, ctx->flags);
736}
737
738static int parse_btf_bitfield(struct fetch_insn **pcode,
739 struct traceprobe_parse_context *ctx)
740{
741 struct fetch_insn *code = *pcode;
742
743 if ((ctx->last_bitsize % 8 == 0) && ctx->last_bitoffs == 0)
744 return 0;
745
746 code++;
747 if (code->op != FETCH_OP_NOP) {
748 trace_probe_log_err(ctx->offset, TOO_MANY_OPS);
749 return -EINVAL;
750 }
751 *pcode = code;
752
753 code->op = FETCH_OP_MOD_BF;
754 code->lshift = 64 - (ctx->last_bitsize + ctx->last_bitoffs);
755 code->rshift = 64 - ctx->last_bitsize;
756 code->basesize = 64 / 8;
757 return 0;
758}
759
760#else
761static void clear_btf_context(struct traceprobe_parse_context *ctx)
762{
763 ctx->btf = NULL;
764}
765
766static int query_btf_context(struct traceprobe_parse_context *ctx)
767{
768 return -EOPNOTSUPP;
769}
770
771static int parse_btf_arg(char *varname,
772 struct fetch_insn **pcode, struct fetch_insn *end,
773 struct traceprobe_parse_context *ctx)
774{
775 trace_probe_log_err(ctx->offset, NOSUP_BTFARG);
776 return -EOPNOTSUPP;
777}
778
779static int parse_btf_bitfield(struct fetch_insn **pcode,
780 struct traceprobe_parse_context *ctx)
781{
782 trace_probe_log_err(ctx->offset, NOSUP_BTFARG);
783 return -EOPNOTSUPP;
784}
785
786#define find_fetch_type_from_btf_type(ctx) \
787 find_fetch_type(NULL, ctx->flags)
788
789static int check_prepare_btf_string_fetch(char *typename,
790 struct fetch_insn **pcode,
791 struct traceprobe_parse_context *ctx)
792{
793 return 0;
794}
795
796#endif
797
798#ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API
799
800static void store_entry_arg_at(struct fetch_insn *code, int argnum, int offset)
801{
802 code[0].op = FETCH_OP_ARG;
803 code[0].param = argnum;
804 code[1].op = FETCH_OP_ST_EDATA;
805 code[1].offset = offset;
806}
807
808static int get_entry_arg_max_offset(struct probe_entry_arg *earg)
809{
810 int i, max_offset = 0;
811
812 /*
813 * earg->code[] array has an operation sequence which is run in
814 * the entry handler.
815 * The sequence stopped by FETCH_OP_END and each data stored in
816 * the entry data buffer by FETCH_OP_ST_EDATA. The FETCH_OP_ST_EDATA
817 * stores the data at the data buffer + its offset, and all data are
818 * "unsigned long" size. The offset must be increased when a data is
819 * stored. Thus we need to find the last FETCH_OP_ST_EDATA in the
820 * code array.
821 */
822 for (i = 0; i < earg->size - 1 && earg->code[i].op != FETCH_OP_END; i++) {
823 if (earg->code[i].op == FETCH_OP_ST_EDATA)
824 if (earg->code[i].offset > max_offset)
825 max_offset = earg->code[i].offset;
826 }
827 return max_offset;
828}
829
830/*
831 * Add the entry code to store the 'argnum'th parameter and return the offset
832 * in the entry data buffer where the data will be stored.
833 */
834static int __store_entry_arg(struct trace_probe *tp, int argnum)
835{
836 struct probe_entry_arg *earg = tp->entry_arg;
837 int i, offset, last_offset = 0;
838
839 if (!earg) {
840 earg = kzalloc(sizeof(*tp->entry_arg), GFP_KERNEL);
841 if (!earg)
842 return -ENOMEM;
843 earg->size = 2 * tp->nr_args + 1;
844 earg->code = kcalloc(earg->size, sizeof(struct fetch_insn),
845 GFP_KERNEL);
846 if (!earg->code) {
847 kfree(objp: earg);
848 return -ENOMEM;
849 }
850 /* Fill the code buffer with 'end' to simplify it */
851 for (i = 0; i < earg->size; i++)
852 earg->code[i].op = FETCH_OP_END;
853 tp->entry_arg = earg;
854 store_entry_arg_at(code: earg->code, argnum, offset: 0);
855 return 0;
856 }
857
858 /*
859 * NOTE: if anyone change the following rule, please rewrite this.
860 * The entry code array is filled with the pair of
861 *
862 * [FETCH_OP_ARG(argnum)]
863 * [FETCH_OP_ST_EDATA(offset of entry data buffer)]
864 *
865 * and the rest of entries are filled with [FETCH_OP_END].
866 * The offset should be incremented, thus the last pair should
867 * have the largest offset.
868 */
869
870 /* Search the offset for the sprcified argnum. */
871 for (i = 0; i < earg->size - 1 && earg->code[i].op != FETCH_OP_END; i += 2) {
872 if (WARN_ON_ONCE(earg->code[i].op != FETCH_OP_ARG))
873 return -EINVAL;
874
875 if (earg->code[i].param != argnum)
876 continue;
877
878 if (WARN_ON_ONCE(earg->code[i + 1].op != FETCH_OP_ST_EDATA))
879 return -EINVAL;
880
881 return earg->code[i + 1].offset;
882 }
883 /* Not found, append new entry if possible. */
884 if (i >= earg->size - 1)
885 return -ENOSPC;
886
887 /* The last entry must have the largest offset. */
888 if (i != 0) {
889 if (WARN_ON_ONCE(earg->code[i - 1].op != FETCH_OP_ST_EDATA))
890 return -EINVAL;
891 last_offset = earg->code[i - 1].offset;
892 }
893
894 offset = last_offset + sizeof(unsigned long);
895 store_entry_arg_at(code: &earg->code[i], argnum, offset);
896 return offset;
897}
898
899int traceprobe_get_entry_data_size(struct trace_probe *tp)
900{
901 struct probe_entry_arg *earg = tp->entry_arg;
902
903 if (!earg)
904 return 0;
905
906 return get_entry_arg_max_offset(earg) + sizeof(unsigned long);
907}
908
909void store_trace_entry_data(void *edata, struct trace_probe *tp, struct pt_regs *regs)
910{
911 struct probe_entry_arg *earg = tp->entry_arg;
912 unsigned long val = 0;
913 int i;
914
915 if (!earg)
916 return;
917
918 for (i = 0; i < earg->size; i++) {
919 struct fetch_insn *code = &earg->code[i];
920
921 switch (code->op) {
922 case FETCH_OP_ARG:
923 val = regs_get_kernel_argument(regs, n: code->param);
924 break;
925 case FETCH_OP_ST_EDATA:
926 *(unsigned long *)((unsigned long)edata + code->offset) = val;
927 break;
928 case FETCH_OP_END:
929 goto end;
930 default:
931 break;
932 }
933 }
934end:
935 return;
936}
937NOKPROBE_SYMBOL(store_trace_entry_data)
938#endif
939
940#define PARAM_MAX_STACK (THREAD_SIZE / sizeof(unsigned long))
941
942/* Parse $vars. @orig_arg points '$', which syncs to @ctx->offset */
943static int parse_probe_vars(char *orig_arg, const struct fetch_type *t,
944 struct fetch_insn **pcode,
945 struct fetch_insn *end,
946 struct traceprobe_parse_context *ctx)
947{
948 struct fetch_insn *code = *pcode;
949 int err = TP_ERR_BAD_VAR;
950 char *arg = orig_arg + 1;
951 unsigned long param;
952 int ret = 0;
953 int len;
954
955 if (ctx->flags & TPARG_FL_TEVENT) {
956 if (code->data)
957 return -EFAULT;
958 ret = parse_trace_event_arg(arg, code, ctx);
959 if (!ret)
960 return 0;
961 if (strcmp(arg, "comm") == 0 || strcmp(arg, "COMM") == 0) {
962 code->op = FETCH_OP_COMM;
963 return 0;
964 }
965 /* backward compatibility */
966 ctx->offset = 0;
967 goto inval;
968 }
969
970 if (str_has_prefix(str: arg, prefix: "retval")) {
971 if (!(ctx->flags & TPARG_FL_RETURN)) {
972 err = TP_ERR_RETVAL_ON_PROBE;
973 goto inval;
974 }
975 if (!(ctx->flags & TPARG_FL_KERNEL) ||
976 !IS_ENABLED(CONFIG_PROBE_EVENTS_BTF_ARGS)) {
977 code->op = FETCH_OP_RETVAL;
978 return 0;
979 }
980 return parse_btf_arg(varname: orig_arg, pcode, end, ctx);
981 }
982
983 len = str_has_prefix(str: arg, prefix: "stack");
984 if (len) {
985
986 if (arg[len] == '\0') {
987 code->op = FETCH_OP_STACKP;
988 return 0;
989 }
990
991 if (isdigit(c: arg[len])) {
992 ret = kstrtoul(s: arg + len, base: 10, res: &param);
993 if (ret)
994 goto inval;
995
996 if ((ctx->flags & TPARG_FL_KERNEL) &&
997 param > PARAM_MAX_STACK) {
998 err = TP_ERR_BAD_STACK_NUM;
999 goto inval;
1000 }
1001 code->op = FETCH_OP_STACK;
1002 code->param = (unsigned int)param;
1003 return 0;
1004 }
1005 goto inval;
1006 }
1007
1008 if (strcmp(arg, "comm") == 0 || strcmp(arg, "COMM") == 0) {
1009 code->op = FETCH_OP_COMM;
1010 return 0;
1011 }
1012
1013#ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API
1014 len = str_has_prefix(str: arg, prefix: "arg");
1015 if (len) {
1016 ret = kstrtoul(s: arg + len, base: 10, res: &param);
1017 if (ret)
1018 goto inval;
1019
1020 if (!param || param > PARAM_MAX_STACK) {
1021 err = TP_ERR_BAD_ARG_NUM;
1022 goto inval;
1023 }
1024 param--; /* argN starts from 1, but internal arg[N] starts from 0 */
1025
1026 if (tparg_is_function_entry(flags: ctx->flags)) {
1027 code->op = FETCH_OP_ARG;
1028 code->param = (unsigned int)param;
1029 /*
1030 * The tracepoint probe will probe a stub function, and the
1031 * first parameter of the stub is a dummy and should be ignored.
1032 */
1033 if (ctx->flags & TPARG_FL_TPOINT)
1034 code->param++;
1035 } else if (tparg_is_function_return(flags: ctx->flags)) {
1036 /* function entry argument access from return probe */
1037 ret = __store_entry_arg(tp: ctx->tp, argnum: param);
1038 if (ret < 0) /* This error should be an internal error */
1039 return ret;
1040
1041 code->op = FETCH_OP_EDATA;
1042 code->offset = ret;
1043 } else {
1044 err = TP_ERR_NOFENTRY_ARGS;
1045 goto inval;
1046 }
1047 return 0;
1048 }
1049#endif
1050
1051inval:
1052 __trace_probe_log_err(offset: ctx->offset, err_type: err);
1053 return -EINVAL;
1054}
1055
1056static int str_to_immediate(char *str, unsigned long *imm)
1057{
1058 if (isdigit(c: str[0]))
1059 return kstrtoul(s: str, base: 0, res: imm);
1060 else if (str[0] == '-')
1061 return kstrtol(s: str, base: 0, res: (long *)imm);
1062 else if (str[0] == '+')
1063 return kstrtol(s: str + 1, base: 0, res: (long *)imm);
1064 return -EINVAL;
1065}
1066
1067static int __parse_imm_string(char *str, char **pbuf, int offs)
1068{
1069 size_t len = strlen(str);
1070
1071 if (str[len - 1] != '"') {
1072 trace_probe_log_err(offs + len, IMMSTR_NO_CLOSE);
1073 return -EINVAL;
1074 }
1075 *pbuf = kstrndup(s: str, len: len - 1, GFP_KERNEL);
1076 if (!*pbuf)
1077 return -ENOMEM;
1078 return 0;
1079}
1080
1081/* Recursive argument parser */
1082static int
1083parse_probe_arg(char *arg, const struct fetch_type *type,
1084 struct fetch_insn **pcode, struct fetch_insn *end,
1085 struct traceprobe_parse_context *ctx)
1086{
1087 struct fetch_insn *code = *pcode;
1088 unsigned long param;
1089 int deref = FETCH_OP_DEREF;
1090 long offset = 0;
1091 char *tmp;
1092 int ret = 0;
1093
1094 switch (arg[0]) {
1095 case '$':
1096 ret = parse_probe_vars(orig_arg: arg, t: type, pcode, end, ctx);
1097 break;
1098
1099 case '%': /* named register */
1100 if (ctx->flags & (TPARG_FL_TEVENT | TPARG_FL_FPROBE)) {
1101 /* eprobe and fprobe do not handle registers */
1102 trace_probe_log_err(ctx->offset, BAD_VAR);
1103 break;
1104 }
1105 ret = regs_query_register_offset(name: arg + 1);
1106 if (ret >= 0) {
1107 code->op = FETCH_OP_REG;
1108 code->param = (unsigned int)ret;
1109 ret = 0;
1110 } else
1111 trace_probe_log_err(ctx->offset, BAD_REG_NAME);
1112 break;
1113
1114 case '@': /* memory, file-offset or symbol */
1115 if (isdigit(c: arg[1])) {
1116 ret = kstrtoul(s: arg + 1, base: 0, res: &param);
1117 if (ret) {
1118 trace_probe_log_err(ctx->offset, BAD_MEM_ADDR);
1119 break;
1120 }
1121 /* load address */
1122 code->op = FETCH_OP_IMM;
1123 code->immediate = param;
1124 } else if (arg[1] == '+') {
1125 /* kprobes don't support file offsets */
1126 if (ctx->flags & TPARG_FL_KERNEL) {
1127 trace_probe_log_err(ctx->offset, FILE_ON_KPROBE);
1128 return -EINVAL;
1129 }
1130 ret = kstrtol(s: arg + 2, base: 0, res: &offset);
1131 if (ret) {
1132 trace_probe_log_err(ctx->offset, BAD_FILE_OFFS);
1133 break;
1134 }
1135
1136 code->op = FETCH_OP_FOFFS;
1137 code->immediate = (unsigned long)offset; // imm64?
1138 } else {
1139 /* uprobes don't support symbols */
1140 if (!(ctx->flags & TPARG_FL_KERNEL)) {
1141 trace_probe_log_err(ctx->offset, SYM_ON_UPROBE);
1142 return -EINVAL;
1143 }
1144 /* Preserve symbol for updating */
1145 code->op = FETCH_NOP_SYMBOL;
1146 code->data = kstrdup(s: arg + 1, GFP_KERNEL);
1147 if (!code->data)
1148 return -ENOMEM;
1149 if (++code == end) {
1150 trace_probe_log_err(ctx->offset, TOO_MANY_OPS);
1151 return -EINVAL;
1152 }
1153 code->op = FETCH_OP_IMM;
1154 code->immediate = 0;
1155 }
1156 /* These are fetching from memory */
1157 if (++code == end) {
1158 trace_probe_log_err(ctx->offset, TOO_MANY_OPS);
1159 return -EINVAL;
1160 }
1161 *pcode = code;
1162 code->op = FETCH_OP_DEREF;
1163 code->offset = offset;
1164 break;
1165
1166 case '+': /* deref memory */
1167 case '-':
1168 if (arg[1] == 'u') {
1169 deref = FETCH_OP_UDEREF;
1170 arg[1] = arg[0];
1171 arg++;
1172 }
1173 if (arg[0] == '+')
1174 arg++; /* Skip '+', because kstrtol() rejects it. */
1175 tmp = strchr(arg, '(');
1176 if (!tmp) {
1177 trace_probe_log_err(ctx->offset, DEREF_NEED_BRACE);
1178 return -EINVAL;
1179 }
1180 *tmp = '\0';
1181 ret = kstrtol(s: arg, base: 0, res: &offset);
1182 if (ret) {
1183 trace_probe_log_err(ctx->offset, BAD_DEREF_OFFS);
1184 break;
1185 }
1186 ctx->offset += (tmp + 1 - arg) + (arg[0] != '-' ? 1 : 0);
1187 arg = tmp + 1;
1188 tmp = strrchr(arg, ')');
1189 if (!tmp) {
1190 trace_probe_log_err(ctx->offset + strlen(arg),
1191 DEREF_OPEN_BRACE);
1192 return -EINVAL;
1193 } else {
1194 const struct fetch_type *t2 = find_fetch_type(NULL, flags: ctx->flags);
1195 int cur_offs = ctx->offset;
1196
1197 *tmp = '\0';
1198 ret = parse_probe_arg(arg, type: t2, pcode: &code, end, ctx);
1199 if (ret)
1200 break;
1201 ctx->offset = cur_offs;
1202 if (code->op == FETCH_OP_COMM ||
1203 code->op == FETCH_OP_DATA) {
1204 trace_probe_log_err(ctx->offset, COMM_CANT_DEREF);
1205 return -EINVAL;
1206 }
1207 if (++code == end) {
1208 trace_probe_log_err(ctx->offset, TOO_MANY_OPS);
1209 return -EINVAL;
1210 }
1211 *pcode = code;
1212
1213 code->op = deref;
1214 code->offset = offset;
1215 /* Reset the last type if used */
1216 ctx->last_type = NULL;
1217 }
1218 break;
1219 case '\\': /* Immediate value */
1220 if (arg[1] == '"') { /* Immediate string */
1221 ret = __parse_imm_string(str: arg + 2, pbuf: &tmp, offs: ctx->offset + 2);
1222 if (ret)
1223 break;
1224 code->op = FETCH_OP_DATA;
1225 code->data = tmp;
1226 } else {
1227 ret = str_to_immediate(str: arg + 1, imm: &code->immediate);
1228 if (ret)
1229 trace_probe_log_err(ctx->offset + 1, BAD_IMM);
1230 else
1231 code->op = FETCH_OP_IMM;
1232 }
1233 break;
1234 default:
1235 if (isalpha(arg[0]) || arg[0] == '_') { /* BTF variable */
1236 if (!tparg_is_function_entry(flags: ctx->flags) &&
1237 !tparg_is_function_return(flags: ctx->flags)) {
1238 trace_probe_log_err(ctx->offset, NOSUP_BTFARG);
1239 return -EINVAL;
1240 }
1241 ret = parse_btf_arg(varname: arg, pcode, end, ctx);
1242 break;
1243 }
1244 }
1245 if (!ret && code->op == FETCH_OP_NOP) {
1246 /* Parsed, but do not find fetch method */
1247 trace_probe_log_err(ctx->offset, BAD_FETCH_ARG);
1248 ret = -EINVAL;
1249 }
1250 return ret;
1251}
1252
1253/* Bitfield type needs to be parsed into a fetch function */
1254static int __parse_bitfield_probe_arg(const char *bf,
1255 const struct fetch_type *t,
1256 struct fetch_insn **pcode)
1257{
1258 struct fetch_insn *code = *pcode;
1259 unsigned long bw, bo;
1260 char *tail;
1261
1262 if (*bf != 'b')
1263 return 0;
1264
1265 bw = simple_strtoul(bf + 1, &tail, 0); /* Use simple one */
1266
1267 if (bw == 0 || *tail != '@')
1268 return -EINVAL;
1269
1270 bf = tail + 1;
1271 bo = simple_strtoul(bf, &tail, 0);
1272
1273 if (tail == bf || *tail != '/')
1274 return -EINVAL;
1275 code++;
1276 if (code->op != FETCH_OP_NOP)
1277 return -EINVAL;
1278 *pcode = code;
1279
1280 code->op = FETCH_OP_MOD_BF;
1281 code->lshift = BYTES_TO_BITS(t->size) - (bw + bo);
1282 code->rshift = BYTES_TO_BITS(t->size) - bw;
1283 code->basesize = t->size;
1284
1285 return (BYTES_TO_BITS(t->size) < (bw + bo)) ? -EINVAL : 0;
1286}
1287
1288/* Split type part from @arg and return it. */
1289static char *parse_probe_arg_type(char *arg, struct probe_arg *parg,
1290 struct traceprobe_parse_context *ctx)
1291{
1292 char *t = NULL, *t2, *t3;
1293 int offs;
1294
1295 t = strchr(arg, ':');
1296 if (t) {
1297 *t++ = '\0';
1298 t2 = strchr(t, '[');
1299 if (t2) {
1300 *t2++ = '\0';
1301 t3 = strchr(t2, ']');
1302 if (!t3) {
1303 offs = t2 + strlen(t2) - arg;
1304
1305 trace_probe_log_err(ctx->offset + offs,
1306 ARRAY_NO_CLOSE);
1307 return ERR_PTR(error: -EINVAL);
1308 } else if (t3[1] != '\0') {
1309 trace_probe_log_err(ctx->offset + t3 + 1 - arg,
1310 BAD_ARRAY_SUFFIX);
1311 return ERR_PTR(error: -EINVAL);
1312 }
1313 *t3 = '\0';
1314 if (kstrtouint(s: t2, base: 0, res: &parg->count) || !parg->count) {
1315 trace_probe_log_err(ctx->offset + t2 - arg,
1316 BAD_ARRAY_NUM);
1317 return ERR_PTR(error: -EINVAL);
1318 }
1319 if (parg->count > MAX_ARRAY_LEN) {
1320 trace_probe_log_err(ctx->offset + t2 - arg,
1321 ARRAY_TOO_BIG);
1322 return ERR_PTR(error: -EINVAL);
1323 }
1324 }
1325 }
1326 offs = t ? t - arg : 0;
1327
1328 /*
1329 * Since $comm and immediate string can not be dereferenced,
1330 * we can find those by strcmp. But ignore for eprobes.
1331 */
1332 if (!(ctx->flags & TPARG_FL_TEVENT) &&
1333 (strcmp(arg, "$comm") == 0 || strcmp(arg, "$COMM") == 0 ||
1334 strncmp(arg, "\\\"", 2) == 0)) {
1335 /* The type of $comm must be "string", and not an array type. */
1336 if (parg->count || (t && strcmp(t, "string"))) {
1337 trace_probe_log_err(ctx->offset + offs, NEED_STRING_TYPE);
1338 return ERR_PTR(error: -EINVAL);
1339 }
1340 parg->type = find_fetch_type(type: "string", flags: ctx->flags);
1341 } else
1342 parg->type = find_fetch_type(type: t, flags: ctx->flags);
1343
1344 if (!parg->type) {
1345 trace_probe_log_err(ctx->offset + offs, BAD_TYPE);
1346 return ERR_PTR(error: -EINVAL);
1347 }
1348
1349 return t;
1350}
1351
1352/* After parsing, adjust the fetch_insn according to the probe_arg */
1353static int finalize_fetch_insn(struct fetch_insn *code,
1354 struct probe_arg *parg,
1355 char *type,
1356 int type_offset,
1357 struct traceprobe_parse_context *ctx)
1358{
1359 struct fetch_insn *scode;
1360 int ret;
1361
1362 /* Store operation */
1363 if (parg->type->is_string) {
1364 /* Check bad combination of the type and the last fetch_insn. */
1365 if (!strcmp(parg->type->name, "symstr")) {
1366 if (code->op != FETCH_OP_REG && code->op != FETCH_OP_STACK &&
1367 code->op != FETCH_OP_RETVAL && code->op != FETCH_OP_ARG &&
1368 code->op != FETCH_OP_DEREF && code->op != FETCH_OP_TP_ARG) {
1369 trace_probe_log_err(ctx->offset + type_offset,
1370 BAD_SYMSTRING);
1371 return -EINVAL;
1372 }
1373 } else {
1374 if (code->op != FETCH_OP_DEREF && code->op != FETCH_OP_UDEREF &&
1375 code->op != FETCH_OP_IMM && code->op != FETCH_OP_COMM &&
1376 code->op != FETCH_OP_DATA && code->op != FETCH_OP_TP_ARG) {
1377 trace_probe_log_err(ctx->offset + type_offset,
1378 BAD_STRING);
1379 return -EINVAL;
1380 }
1381 }
1382
1383 if (!strcmp(parg->type->name, "symstr") ||
1384 (code->op == FETCH_OP_IMM || code->op == FETCH_OP_COMM ||
1385 code->op == FETCH_OP_DATA) || code->op == FETCH_OP_TP_ARG ||
1386 parg->count) {
1387 /*
1388 * IMM, DATA and COMM is pointing actual address, those
1389 * must be kept, and if parg->count != 0, this is an
1390 * array of string pointers instead of string address
1391 * itself.
1392 * For the symstr, it doesn't need to dereference, thus
1393 * it just get the value.
1394 */
1395 code++;
1396 if (code->op != FETCH_OP_NOP) {
1397 trace_probe_log_err(ctx->offset, TOO_MANY_OPS);
1398 return -EINVAL;
1399 }
1400 }
1401
1402 /* If op == DEREF, replace it with STRING */
1403 if (!strcmp(parg->type->name, "ustring") ||
1404 code->op == FETCH_OP_UDEREF)
1405 code->op = FETCH_OP_ST_USTRING;
1406 else if (!strcmp(parg->type->name, "symstr"))
1407 code->op = FETCH_OP_ST_SYMSTR;
1408 else
1409 code->op = FETCH_OP_ST_STRING;
1410 code->size = parg->type->size;
1411 parg->dynamic = true;
1412 } else if (code->op == FETCH_OP_DEREF) {
1413 code->op = FETCH_OP_ST_MEM;
1414 code->size = parg->type->size;
1415 } else if (code->op == FETCH_OP_UDEREF) {
1416 code->op = FETCH_OP_ST_UMEM;
1417 code->size = parg->type->size;
1418 } else {
1419 code++;
1420 if (code->op != FETCH_OP_NOP) {
1421 trace_probe_log_err(ctx->offset, TOO_MANY_OPS);
1422 return -E2BIG;
1423 }
1424 code->op = FETCH_OP_ST_RAW;
1425 code->size = parg->type->size;
1426 }
1427
1428 /* Save storing fetch_insn. */
1429 scode = code;
1430
1431 /* Modify operation */
1432 if (type != NULL) {
1433 /* Bitfield needs a special fetch_insn. */
1434 ret = __parse_bitfield_probe_arg(bf: type, t: parg->type, pcode: &code);
1435 if (ret) {
1436 trace_probe_log_err(ctx->offset + type_offset, BAD_BITFIELD);
1437 return ret;
1438 }
1439 } else if (IS_ENABLED(CONFIG_PROBE_EVENTS_BTF_ARGS) &&
1440 ctx->last_type) {
1441 /* If user not specified the type, try parsing BTF bitfield. */
1442 ret = parse_btf_bitfield(pcode: &code, ctx);
1443 if (ret)
1444 return ret;
1445 }
1446
1447 /* Loop(Array) operation */
1448 if (parg->count) {
1449 if (scode->op != FETCH_OP_ST_MEM &&
1450 scode->op != FETCH_OP_ST_STRING &&
1451 scode->op != FETCH_OP_ST_USTRING) {
1452 trace_probe_log_err(ctx->offset + type_offset, BAD_STRING);
1453 return -EINVAL;
1454 }
1455 code++;
1456 if (code->op != FETCH_OP_NOP) {
1457 trace_probe_log_err(ctx->offset, TOO_MANY_OPS);
1458 return -E2BIG;
1459 }
1460 code->op = FETCH_OP_LP_ARRAY;
1461 code->param = parg->count;
1462 }
1463
1464 /* Finalize the fetch_insn array. */
1465 code++;
1466 code->op = FETCH_OP_END;
1467
1468 return 0;
1469}
1470
1471/* String length checking wrapper */
1472static int traceprobe_parse_probe_arg_body(const char *argv, ssize_t *size,
1473 struct probe_arg *parg,
1474 struct traceprobe_parse_context *ctx)
1475{
1476 struct fetch_insn *code, *tmp = NULL;
1477 char *type, *arg __free(kfree) = NULL;
1478 int ret, len;
1479
1480 len = strlen(argv);
1481 if (len > MAX_ARGSTR_LEN) {
1482 trace_probe_log_err(ctx->offset, ARG_TOO_LONG);
1483 return -E2BIG;
1484 } else if (len == 0) {
1485 trace_probe_log_err(ctx->offset, NO_ARG_BODY);
1486 return -EINVAL;
1487 }
1488
1489 arg = kstrdup(s: argv, GFP_KERNEL);
1490 if (!arg)
1491 return -ENOMEM;
1492
1493 parg->comm = kstrdup(s: arg, GFP_KERNEL);
1494 if (!parg->comm)
1495 return -ENOMEM;
1496
1497 type = parse_probe_arg_type(arg, parg, ctx);
1498 if (IS_ERR(ptr: type))
1499 return PTR_ERR(ptr: type);
1500
1501 code = tmp = kcalloc(FETCH_INSN_MAX, sizeof(*code), GFP_KERNEL);
1502 if (!code)
1503 return -ENOMEM;
1504 code[FETCH_INSN_MAX - 1].op = FETCH_OP_END;
1505
1506 ctx->last_type = NULL;
1507 ret = parse_probe_arg(arg, type: parg->type, pcode: &code, end: &code[FETCH_INSN_MAX - 1],
1508 ctx);
1509 if (ret < 0)
1510 goto fail;
1511
1512 /* Update storing type if BTF is available */
1513 if (IS_ENABLED(CONFIG_PROBE_EVENTS_BTF_ARGS) &&
1514 ctx->last_type) {
1515 if (!type) {
1516 parg->type = find_fetch_type_from_btf_type(ctx);
1517 } else if (strstr(type, "string")) {
1518 ret = check_prepare_btf_string_fetch(typename: type, pcode: &code, ctx);
1519 if (ret)
1520 goto fail;
1521 }
1522 }
1523 parg->offset = *size;
1524 *size += parg->type->size * (parg->count ?: 1);
1525
1526 if (parg->count) {
1527 len = strlen(parg->type->fmttype) + 6;
1528 parg->fmt = kmalloc(len, GFP_KERNEL);
1529 if (!parg->fmt) {
1530 ret = -ENOMEM;
1531 goto fail;
1532 }
1533 snprintf(buf: parg->fmt, size: len, fmt: "%s[%d]", parg->type->fmttype,
1534 parg->count);
1535 }
1536
1537 ret = finalize_fetch_insn(code, parg, type, type_offset: type ? type - arg : 0, ctx);
1538 if (ret < 0)
1539 goto fail;
1540
1541 for (; code < tmp + FETCH_INSN_MAX; code++)
1542 if (code->op == FETCH_OP_END)
1543 break;
1544 /* Shrink down the code buffer */
1545 parg->code = kcalloc(code - tmp + 1, sizeof(*code), GFP_KERNEL);
1546 if (!parg->code)
1547 ret = -ENOMEM;
1548 else
1549 memcpy(to: parg->code, from: tmp, len: sizeof(*code) * (code - tmp + 1));
1550
1551fail:
1552 if (ret < 0) {
1553 for (code = tmp; code < tmp + FETCH_INSN_MAX; code++)
1554 if (code->op == FETCH_NOP_SYMBOL ||
1555 code->op == FETCH_OP_DATA)
1556 kfree(objp: code->data);
1557 }
1558 kfree(objp: tmp);
1559
1560 return ret;
1561}
1562
1563/* Return 1 if name is reserved or already used by another argument */
1564static int traceprobe_conflict_field_name(const char *name,
1565 struct probe_arg *args, int narg)
1566{
1567 int i;
1568
1569 for (i = 0; i < ARRAY_SIZE(reserved_field_names); i++)
1570 if (strcmp(reserved_field_names[i], name) == 0)
1571 return 1;
1572
1573 for (i = 0; i < narg; i++)
1574 if (strcmp(args[i].name, name) == 0)
1575 return 1;
1576
1577 return 0;
1578}
1579
1580static char *generate_probe_arg_name(const char *arg, int idx)
1581{
1582 char *name = NULL;
1583 const char *end;
1584
1585 /*
1586 * If argument name is omitted, try arg as a name (BTF variable)
1587 * or "argN".
1588 */
1589 if (IS_ENABLED(CONFIG_PROBE_EVENTS_BTF_ARGS)) {
1590 end = strchr(arg, ':');
1591 if (!end)
1592 end = arg + strlen(arg);
1593
1594 name = kmemdup_nul(s: arg, len: end - arg, GFP_KERNEL);
1595 if (!name || !is_good_name(name)) {
1596 kfree(objp: name);
1597 name = NULL;
1598 }
1599 }
1600
1601 if (!name)
1602 name = kasprintf(GFP_KERNEL, fmt: "arg%d", idx + 1);
1603
1604 return name;
1605}
1606
1607int traceprobe_parse_probe_arg(struct trace_probe *tp, int i, const char *arg,
1608 struct traceprobe_parse_context *ctx)
1609{
1610 struct probe_arg *parg = &tp->args[i];
1611 const char *body;
1612
1613 ctx->tp = tp;
1614 body = strchr(arg, '=');
1615 if (body) {
1616 if (body - arg > MAX_ARG_NAME_LEN) {
1617 trace_probe_log_err(0, ARG_NAME_TOO_LONG);
1618 return -EINVAL;
1619 } else if (body == arg) {
1620 trace_probe_log_err(0, NO_ARG_NAME);
1621 return -EINVAL;
1622 }
1623 parg->name = kmemdup_nul(s: arg, len: body - arg, GFP_KERNEL);
1624 body++;
1625 } else {
1626 parg->name = generate_probe_arg_name(arg, idx: i);
1627 body = arg;
1628 }
1629 if (!parg->name)
1630 return -ENOMEM;
1631
1632 if (!is_good_name(name: parg->name)) {
1633 trace_probe_log_err(0, BAD_ARG_NAME);
1634 return -EINVAL;
1635 }
1636 if (traceprobe_conflict_field_name(name: parg->name, args: tp->args, narg: i)) {
1637 trace_probe_log_err(0, USED_ARG_NAME);
1638 return -EINVAL;
1639 }
1640 ctx->offset = body - arg;
1641 /* Parse fetch argument */
1642 return traceprobe_parse_probe_arg_body(argv: body, size: &tp->size, parg, ctx);
1643}
1644
1645void traceprobe_free_probe_arg(struct probe_arg *arg)
1646{
1647 struct fetch_insn *code = arg->code;
1648
1649 while (code && code->op != FETCH_OP_END) {
1650 if (code->op == FETCH_NOP_SYMBOL ||
1651 code->op == FETCH_OP_DATA)
1652 kfree(objp: code->data);
1653 code++;
1654 }
1655 kfree(objp: arg->code);
1656 kfree(objp: arg->name);
1657 kfree(objp: arg->comm);
1658 kfree(objp: arg->fmt);
1659}
1660
1661static int argv_has_var_arg(int argc, const char *argv[], int *args_idx,
1662 struct traceprobe_parse_context *ctx)
1663{
1664 int i, found = 0;
1665
1666 for (i = 0; i < argc; i++)
1667 if (str_has_prefix(str: argv[i], prefix: "$arg")) {
1668 trace_probe_log_set_index(index: i + 2);
1669
1670 if (!tparg_is_function_entry(flags: ctx->flags) &&
1671 !tparg_is_function_return(flags: ctx->flags)) {
1672 trace_probe_log_err(0, NOFENTRY_ARGS);
1673 return -EINVAL;
1674 }
1675
1676 if (isdigit(c: argv[i][4])) {
1677 found = 1;
1678 continue;
1679 }
1680
1681 if (argv[i][4] != '*') {
1682 trace_probe_log_err(0, BAD_VAR);
1683 return -EINVAL;
1684 }
1685
1686 if (*args_idx >= 0 && *args_idx < argc) {
1687 trace_probe_log_err(0, DOUBLE_ARGS);
1688 return -EINVAL;
1689 }
1690 found = 1;
1691 *args_idx = i;
1692 }
1693
1694 return found;
1695}
1696
1697static int sprint_nth_btf_arg(int idx, const char *type,
1698 char *buf, int bufsize,
1699 struct traceprobe_parse_context *ctx)
1700{
1701 const char *name;
1702 int ret;
1703
1704 if (idx >= ctx->nr_params) {
1705 trace_probe_log_err(0, NO_BTFARG);
1706 return -ENOENT;
1707 }
1708 name = btf_name_by_offset(btf: ctx->btf, offset: ctx->params[idx].name_off);
1709 if (!name) {
1710 trace_probe_log_err(0, NO_BTF_ENTRY);
1711 return -ENOENT;
1712 }
1713 ret = snprintf(buf, size: bufsize, fmt: "%s%s", name, type);
1714 if (ret >= bufsize) {
1715 trace_probe_log_err(0, ARGS_2LONG);
1716 return -E2BIG;
1717 }
1718 return ret;
1719}
1720
1721/* Return new_argv which must be freed after use */
1722const char **traceprobe_expand_meta_args(int argc, const char *argv[],
1723 int *new_argc, char *buf, int bufsize,
1724 struct traceprobe_parse_context *ctx)
1725{
1726 const struct btf_param *params = NULL;
1727 int i, j, n, used, ret, args_idx = -1;
1728 const char **new_argv __free(kfree) = NULL;
1729
1730 ret = argv_has_var_arg(argc, argv, args_idx: &args_idx, ctx);
1731 if (ret < 0)
1732 return ERR_PTR(error: ret);
1733
1734 if (!ret) {
1735 *new_argc = argc;
1736 return NULL;
1737 }
1738
1739 ret = query_btf_context(ctx);
1740 if (ret < 0 || ctx->nr_params == 0) {
1741 if (args_idx != -1) {
1742 /* $arg* requires BTF info */
1743 trace_probe_log_err(0, NOSUP_BTFARG);
1744 return (const char **)params;
1745 }
1746 *new_argc = argc;
1747 return NULL;
1748 }
1749
1750 if (args_idx >= 0)
1751 *new_argc = argc + ctx->nr_params - 1;
1752 else
1753 *new_argc = argc;
1754
1755 new_argv = kcalloc(*new_argc, sizeof(char *), GFP_KERNEL);
1756 if (!new_argv)
1757 return ERR_PTR(error: -ENOMEM);
1758
1759 used = 0;
1760 for (i = 0, j = 0; i < argc; i++) {
1761 trace_probe_log_set_index(index: i + 2);
1762 if (i == args_idx) {
1763 for (n = 0; n < ctx->nr_params; n++) {
1764 ret = sprint_nth_btf_arg(idx: n, type: "", buf: buf + used,
1765 bufsize: bufsize - used, ctx);
1766 if (ret < 0)
1767 return ERR_PTR(error: ret);
1768
1769 new_argv[j++] = buf + used;
1770 used += ret + 1;
1771 }
1772 continue;
1773 }
1774
1775 if (str_has_prefix(str: argv[i], prefix: "$arg")) {
1776 char *type = NULL;
1777
1778 n = simple_strtoul(argv[i] + 4, &type, 10);
1779 if (type && !(*type == ':' || *type == '\0')) {
1780 trace_probe_log_err(0, BAD_VAR);
1781 return ERR_PTR(error: -ENOENT);
1782 }
1783 /* Note: $argN starts from $arg1 */
1784 ret = sprint_nth_btf_arg(idx: n - 1, type, buf: buf + used,
1785 bufsize: bufsize - used, ctx);
1786 if (ret < 0)
1787 return ERR_PTR(error: ret);
1788 new_argv[j++] = buf + used;
1789 used += ret + 1;
1790 } else
1791 new_argv[j++] = argv[i];
1792 }
1793
1794 return_ptr(new_argv);
1795}
1796
1797/* @buf: *buf must be equal to NULL. Caller must to free *buf */
1798int traceprobe_expand_dentry_args(int argc, const char *argv[], char **buf)
1799{
1800 int i, used, ret;
1801 const int bufsize = MAX_DENTRY_ARGS_LEN;
1802 char *tmpbuf __free(kfree) = NULL;
1803
1804 if (*buf)
1805 return -EINVAL;
1806
1807 used = 0;
1808 for (i = 0; i < argc; i++) {
1809 char *tmp __free(kfree) = NULL;
1810 char *equal;
1811 size_t arg_len;
1812
1813 if (!glob_match(pat: "*:%p[dD]", str: argv[i]))
1814 continue;
1815
1816 if (!tmpbuf) {
1817 tmpbuf = kmalloc(bufsize, GFP_KERNEL);
1818 if (!tmpbuf)
1819 return -ENOMEM;
1820 }
1821
1822 tmp = kstrdup(s: argv[i], GFP_KERNEL);
1823 if (!tmp)
1824 return -ENOMEM;
1825
1826 equal = strchr(tmp, '=');
1827 if (equal)
1828 *equal = '\0';
1829 arg_len = strlen(argv[i]);
1830 tmp[arg_len - 4] = '\0';
1831 if (argv[i][arg_len - 1] == 'd')
1832 ret = snprintf(buf: tmpbuf + used, size: bufsize - used,
1833 fmt: "%s%s+0x0(+0x%zx(%s)):string",
1834 equal ? tmp : "", equal ? "=" : "",
1835 offsetof(struct dentry, d_name.name),
1836 equal ? equal + 1 : tmp);
1837 else
1838 ret = snprintf(buf: tmpbuf + used, size: bufsize - used,
1839 fmt: "%s%s+0x0(+0x%zx(+0x%zx(%s))):string",
1840 equal ? tmp : "", equal ? "=" : "",
1841 offsetof(struct dentry, d_name.name),
1842 offsetof(struct file, f_path.dentry),
1843 equal ? equal + 1 : tmp);
1844
1845 if (ret >= bufsize - used)
1846 return -ENOMEM;
1847 argv[i] = tmpbuf + used;
1848 used += ret + 1;
1849 }
1850
1851 *buf = no_free_ptr(tmpbuf);
1852 return 0;
1853}
1854
1855void traceprobe_finish_parse(struct traceprobe_parse_context *ctx)
1856{
1857 clear_btf_context(ctx);
1858}
1859
1860int traceprobe_update_arg(struct probe_arg *arg)
1861{
1862 struct fetch_insn *code = arg->code;
1863 long offset;
1864 char *tmp;
1865 char c;
1866 int ret = 0;
1867
1868 while (code && code->op != FETCH_OP_END) {
1869 if (code->op == FETCH_NOP_SYMBOL) {
1870 if (code[1].op != FETCH_OP_IMM)
1871 return -EINVAL;
1872
1873 tmp = strpbrk(code->data, "+-");
1874 if (tmp)
1875 c = *tmp;
1876 ret = traceprobe_split_symbol_offset(symbol: code->data,
1877 offset: &offset);
1878 if (ret)
1879 return ret;
1880
1881 code[1].immediate =
1882 (unsigned long)kallsyms_lookup_name(name: code->data);
1883 if (tmp)
1884 *tmp = c;
1885 if (!code[1].immediate)
1886 return -ENOENT;
1887 code[1].immediate += offset;
1888 }
1889 code++;
1890 }
1891 return 0;
1892}
1893
1894/* When len=0, we just calculate the needed length */
1895#define LEN_OR_ZERO (len ? len - pos : 0)
1896static int __set_print_fmt(struct trace_probe *tp, char *buf, int len,
1897 enum probe_print_type ptype)
1898{
1899 struct probe_arg *parg;
1900 int i, j;
1901 int pos = 0;
1902 const char *fmt, *arg;
1903
1904 switch (ptype) {
1905 case PROBE_PRINT_NORMAL:
1906 fmt = "(%lx)";
1907 arg = ", REC->" FIELD_STRING_IP;
1908 break;
1909 case PROBE_PRINT_RETURN:
1910 fmt = "(%lx <- %lx)";
1911 arg = ", REC->" FIELD_STRING_FUNC ", REC->" FIELD_STRING_RETIP;
1912 break;
1913 case PROBE_PRINT_EVENT:
1914 fmt = "";
1915 arg = "";
1916 break;
1917 default:
1918 WARN_ON_ONCE(1);
1919 return 0;
1920 }
1921
1922 pos += snprintf(buf: buf + pos, LEN_OR_ZERO, fmt: "\"%s", fmt);
1923
1924 for (i = 0; i < tp->nr_args; i++) {
1925 parg = tp->args + i;
1926 pos += snprintf(buf: buf + pos, LEN_OR_ZERO, fmt: " %s=", parg->name);
1927 if (parg->count) {
1928 pos += snprintf(buf: buf + pos, LEN_OR_ZERO, fmt: "{%s",
1929 parg->type->fmt);
1930 for (j = 1; j < parg->count; j++)
1931 pos += snprintf(buf: buf + pos, LEN_OR_ZERO, fmt: ",%s",
1932 parg->type->fmt);
1933 pos += snprintf(buf: buf + pos, LEN_OR_ZERO, fmt: "}");
1934 } else
1935 pos += snprintf(buf: buf + pos, LEN_OR_ZERO, fmt: "%s",
1936 parg->type->fmt);
1937 }
1938
1939 pos += snprintf(buf: buf + pos, LEN_OR_ZERO, fmt: "\"%s", arg);
1940
1941 for (i = 0; i < tp->nr_args; i++) {
1942 parg = tp->args + i;
1943 if (parg->count) {
1944 if (parg->type->is_string)
1945 fmt = ", __get_str(%s[%d])";
1946 else
1947 fmt = ", REC->%s[%d]";
1948 for (j = 0; j < parg->count; j++)
1949 pos += snprintf(buf: buf + pos, LEN_OR_ZERO,
1950 fmt, parg->name, j);
1951 } else {
1952 if (parg->type->is_string)
1953 fmt = ", __get_str(%s)";
1954 else
1955 fmt = ", REC->%s";
1956 pos += snprintf(buf: buf + pos, LEN_OR_ZERO,
1957 fmt, parg->name);
1958 }
1959 }
1960
1961 /* return the length of print_fmt */
1962 return pos;
1963}
1964#undef LEN_OR_ZERO
1965
1966int traceprobe_set_print_fmt(struct trace_probe *tp, enum probe_print_type ptype)
1967{
1968 struct trace_event_call *call = trace_probe_event_call(tp);
1969 int len;
1970 char *print_fmt;
1971
1972 /* First: called with 0 length to calculate the needed length */
1973 len = __set_print_fmt(tp, NULL, len: 0, ptype);
1974 print_fmt = kmalloc(len + 1, GFP_KERNEL);
1975 if (!print_fmt)
1976 return -ENOMEM;
1977
1978 /* Second: actually write the @print_fmt */
1979 __set_print_fmt(tp, buf: print_fmt, len: len + 1, ptype);
1980 call->print_fmt = print_fmt;
1981
1982 return 0;
1983}
1984
1985int traceprobe_define_arg_fields(struct trace_event_call *event_call,
1986 size_t offset, struct trace_probe *tp)
1987{
1988 int ret, i;
1989
1990 /* Set argument names as fields */
1991 for (i = 0; i < tp->nr_args; i++) {
1992 struct probe_arg *parg = &tp->args[i];
1993 const char *fmt = parg->type->fmttype;
1994 int size = parg->type->size;
1995
1996 if (parg->fmt)
1997 fmt = parg->fmt;
1998 if (parg->count)
1999 size *= parg->count;
2000 ret = trace_define_field(call: event_call, type: fmt, name: parg->name,
2001 offset: offset + parg->offset, size,
2002 is_signed: parg->type->is_signed,
2003 filter_type: FILTER_OTHER);
2004 if (ret)
2005 return ret;
2006 }
2007 return 0;
2008}
2009
2010static void trace_probe_event_free(struct trace_probe_event *tpe)
2011{
2012 kfree(objp: tpe->class.system);
2013 kfree(objp: tpe->call.name);
2014 kfree(objp: tpe->call.print_fmt);
2015 kfree(objp: tpe);
2016}
2017
2018int trace_probe_append(struct trace_probe *tp, struct trace_probe *to)
2019{
2020 if (trace_probe_has_sibling(tp))
2021 return -EBUSY;
2022
2023 list_del_init(entry: &tp->list);
2024 trace_probe_event_free(tpe: tp->event);
2025
2026 tp->event = to->event;
2027 list_add_tail(new: &tp->list, head: trace_probe_probe_list(tp: to));
2028
2029 return 0;
2030}
2031
2032void trace_probe_unlink(struct trace_probe *tp)
2033{
2034 list_del_init(entry: &tp->list);
2035 if (list_empty(head: trace_probe_probe_list(tp)))
2036 trace_probe_event_free(tpe: tp->event);
2037 tp->event = NULL;
2038}
2039
2040void trace_probe_cleanup(struct trace_probe *tp)
2041{
2042 int i;
2043
2044 for (i = 0; i < tp->nr_args; i++)
2045 traceprobe_free_probe_arg(arg: &tp->args[i]);
2046
2047 if (tp->entry_arg) {
2048 kfree(objp: tp->entry_arg->code);
2049 kfree(objp: tp->entry_arg);
2050 tp->entry_arg = NULL;
2051 }
2052
2053 if (tp->event)
2054 trace_probe_unlink(tp);
2055}
2056
2057int trace_probe_init(struct trace_probe *tp, const char *event,
2058 const char *group, bool alloc_filter, int nargs)
2059{
2060 struct trace_event_call *call;
2061 size_t size = sizeof(struct trace_probe_event);
2062 int ret = 0;
2063
2064 if (!event || !group)
2065 return -EINVAL;
2066
2067 if (alloc_filter)
2068 size += sizeof(struct trace_uprobe_filter);
2069
2070 tp->event = kzalloc(size, GFP_KERNEL);
2071 if (!tp->event)
2072 return -ENOMEM;
2073
2074 INIT_LIST_HEAD(list: &tp->event->files);
2075 INIT_LIST_HEAD(list: &tp->event->class.fields);
2076 INIT_LIST_HEAD(list: &tp->event->probes);
2077 INIT_LIST_HEAD(list: &tp->list);
2078 list_add(new: &tp->list, head: &tp->event->probes);
2079
2080 call = trace_probe_event_call(tp);
2081 call->class = &tp->event->class;
2082 call->name = kstrdup(s: event, GFP_KERNEL);
2083 if (!call->name) {
2084 ret = -ENOMEM;
2085 goto error;
2086 }
2087
2088 tp->event->class.system = kstrdup(s: group, GFP_KERNEL);
2089 if (!tp->event->class.system) {
2090 ret = -ENOMEM;
2091 goto error;
2092 }
2093
2094 tp->nr_args = nargs;
2095 /* Make sure pointers in args[] are NULL */
2096 if (nargs)
2097 memset(s: tp->args, c: 0, n: sizeof(tp->args[0]) * nargs);
2098
2099 return 0;
2100
2101error:
2102 trace_probe_cleanup(tp);
2103 return ret;
2104}
2105
2106static struct trace_event_call *
2107find_trace_event_call(const char *system, const char *event_name)
2108{
2109 struct trace_event_call *tp_event;
2110 const char *name;
2111
2112 list_for_each_entry(tp_event, &ftrace_events, list) {
2113 if (!tp_event->class->system ||
2114 strcmp(system, tp_event->class->system))
2115 continue;
2116 name = trace_event_name(call: tp_event);
2117 if (!name || strcmp(event_name, name))
2118 continue;
2119 return tp_event;
2120 }
2121
2122 return NULL;
2123}
2124
2125int trace_probe_register_event_call(struct trace_probe *tp)
2126{
2127 struct trace_event_call *call = trace_probe_event_call(tp);
2128 int ret;
2129
2130 lockdep_assert_held(&event_mutex);
2131
2132 if (find_trace_event_call(system: trace_probe_group_name(tp),
2133 event_name: trace_probe_name(tp)))
2134 return -EEXIST;
2135
2136 ret = register_trace_event(event: &call->event);
2137 if (!ret)
2138 return -ENODEV;
2139
2140 ret = trace_add_event_call(call);
2141 if (ret)
2142 unregister_trace_event(event: &call->event);
2143
2144 return ret;
2145}
2146
2147int trace_probe_add_file(struct trace_probe *tp, struct trace_event_file *file)
2148{
2149 struct event_file_link *link;
2150
2151 link = kmalloc(sizeof(*link), GFP_KERNEL);
2152 if (!link)
2153 return -ENOMEM;
2154
2155 link->file = file;
2156 INIT_LIST_HEAD(list: &link->list);
2157 list_add_tail_rcu(new: &link->list, head: &tp->event->files);
2158 trace_probe_set_flag(tp, TP_FLAG_TRACE);
2159 return 0;
2160}
2161
2162struct event_file_link *trace_probe_get_file_link(struct trace_probe *tp,
2163 struct trace_event_file *file)
2164{
2165 struct event_file_link *link;
2166
2167 trace_probe_for_each_link(link, tp) {
2168 if (link->file == file)
2169 return link;
2170 }
2171
2172 return NULL;
2173}
2174
2175int trace_probe_remove_file(struct trace_probe *tp,
2176 struct trace_event_file *file)
2177{
2178 struct event_file_link *link;
2179
2180 link = trace_probe_get_file_link(tp, file);
2181 if (!link)
2182 return -ENOENT;
2183
2184 list_del_rcu(entry: &link->list);
2185 kvfree_rcu_mightsleep(link);
2186
2187 if (list_empty(head: &tp->event->files))
2188 trace_probe_clear_flag(tp, TP_FLAG_TRACE);
2189
2190 return 0;
2191}
2192
2193/*
2194 * Return the smallest index of different type argument (start from 1).
2195 * If all argument types and name are same, return 0.
2196 */
2197int trace_probe_compare_arg_type(struct trace_probe *a, struct trace_probe *b)
2198{
2199 int i;
2200
2201 /* In case of more arguments */
2202 if (a->nr_args < b->nr_args)
2203 return a->nr_args + 1;
2204 if (a->nr_args > b->nr_args)
2205 return b->nr_args + 1;
2206
2207 for (i = 0; i < a->nr_args; i++) {
2208 if ((b->nr_args <= i) ||
2209 ((a->args[i].type != b->args[i].type) ||
2210 (a->args[i].count != b->args[i].count) ||
2211 strcmp(a->args[i].name, b->args[i].name)))
2212 return i + 1;
2213 }
2214
2215 return 0;
2216}
2217
2218bool trace_probe_match_command_args(struct trace_probe *tp,
2219 int argc, const char **argv)
2220{
2221 char buf[MAX_ARGSTR_LEN + 1];
2222 int i;
2223
2224 if (tp->nr_args < argc)
2225 return false;
2226
2227 for (i = 0; i < argc; i++) {
2228 snprintf(buf, size: sizeof(buf), fmt: "%s=%s",
2229 tp->args[i].name, tp->args[i].comm);
2230 if (strcmp(buf, argv[i]))
2231 return false;
2232 }
2233 return true;
2234}
2235
2236int trace_probe_create(const char *raw_command, int (*createfn)(int, const char **))
2237{
2238 int argc = 0, ret = 0;
2239 char **argv;
2240
2241 argv = argv_split(GFP_KERNEL, str: raw_command, argcp: &argc);
2242 if (!argv)
2243 return -ENOMEM;
2244
2245 if (argc)
2246 ret = createfn(argc, (const char **)argv);
2247
2248 argv_free(argv);
2249
2250 return ret;
2251}
2252
2253int trace_probe_print_args(struct trace_seq *s, struct probe_arg *args, int nr_args,
2254 u8 *data, void *field)
2255{
2256 void *p;
2257 int i, j;
2258
2259 for (i = 0; i < nr_args; i++) {
2260 struct probe_arg *a = args + i;
2261
2262 trace_seq_printf(s, fmt: " %s=", a->name);
2263 if (likely(!a->count)) {
2264 if (!a->type->print(s, data + a->offset, field))
2265 return -ENOMEM;
2266 continue;
2267 }
2268 trace_seq_putc(s, c: '{');
2269 p = data + a->offset;
2270 for (j = 0; j < a->count; j++) {
2271 if (!a->type->print(s, p, field))
2272 return -ENOMEM;
2273 trace_seq_putc(s, c: j == a->count - 1 ? '}' : ',');
2274 p += a->type->size;
2275 }
2276 }
2277 return 0;
2278}
2279