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1// SPDX-License-Identifier: GPL-2.0
2#include <errno.h>
3#include <stdlib.h>
4#include <bpf/bpf.h>
5#include <bpf/btf.h>
6#include <bpf/libbpf.h>
7#include <linux/btf.h>
8#include <linux/err.h>
9#include <linux/string.h>
10#include <internal/lib.h>
11#include <symbol/kallsyms.h>
12#include "bpf-event.h"
13#include "bpf-utils.h"
14#include "debug.h"
15#include "dso.h"
16#include "symbol.h"
17#include "machine.h"
18#include "env.h"
19#include "session.h"
20#include "map.h"
21#include "evlist.h"
22#include "record.h"
23#include "util/synthetic-events.h"
24
25#ifndef HAVE_LIBBPF_BTF__LOAD_FROM_KERNEL_BY_ID
26struct btf *btf__load_from_kernel_by_id(__u32 id)
27{
28 struct btf *btf;
29#pragma GCC diagnostic push
30#pragma GCC diagnostic ignored "-Wdeprecated-declarations"
31 int err = btf__get_from_id(id, &btf);
32#pragma GCC diagnostic pop
33
34 return err ? ERR_PTR(err) : btf;
35}
36#endif
37
38#ifndef HAVE_LIBBPF_BPF_PROG_LOAD
39LIBBPF_API int bpf_load_program(enum bpf_prog_type type,
40 const struct bpf_insn *insns, size_t insns_cnt,
41 const char *license, __u32 kern_version,
42 char *log_buf, size_t log_buf_sz);
43
44int bpf_prog_load(enum bpf_prog_type prog_type,
45 const char *prog_name __maybe_unused,
46 const char *license,
47 const struct bpf_insn *insns, size_t insn_cnt,
48 const struct bpf_prog_load_opts *opts)
49{
50#pragma GCC diagnostic push
51#pragma GCC diagnostic ignored "-Wdeprecated-declarations"
52 return bpf_load_program(prog_type, insns, insn_cnt, license,
53 opts->kern_version, opts->log_buf, opts->log_size);
54#pragma GCC diagnostic pop
55}
56#endif
57
58#ifndef HAVE_LIBBPF_BPF_OBJECT__NEXT_PROGRAM
59struct bpf_program *
60bpf_object__next_program(const struct bpf_object *obj, struct bpf_program *prev)
61{
62#pragma GCC diagnostic push
63#pragma GCC diagnostic ignored "-Wdeprecated-declarations"
64 return bpf_program__next(prev, obj);
65#pragma GCC diagnostic pop
66}
67#endif
68
69#ifndef HAVE_LIBBPF_BPF_OBJECT__NEXT_MAP
70struct bpf_map *
71bpf_object__next_map(const struct bpf_object *obj, const struct bpf_map *prev)
72{
73#pragma GCC diagnostic push
74#pragma GCC diagnostic ignored "-Wdeprecated-declarations"
75 return bpf_map__next(prev, obj);
76#pragma GCC diagnostic pop
77}
78#endif
79
80#ifndef HAVE_LIBBPF_BTF__RAW_DATA
81const void *
82btf__raw_data(const struct btf *btf_ro, __u32 *size)
83{
84#pragma GCC diagnostic push
85#pragma GCC diagnostic ignored "-Wdeprecated-declarations"
86 return btf__get_raw_data(btf_ro, size);
87#pragma GCC diagnostic pop
88}
89#endif
90
91static int snprintf_hex(char *buf, size_t size, unsigned char *data, size_t len)
92{
93 int ret = 0;
94 size_t i;
95
96 for (i = 0; i < len; i++)
97 ret += snprintf(buf + ret, size - ret, "%02x", data[i]);
98 return ret;
99}
100
101static int machine__process_bpf_event_load(struct machine *machine,
102 union perf_event *event,
103 struct perf_sample *sample __maybe_unused)
104{
105 struct bpf_prog_info_node *info_node;
106 struct perf_env *env = machine->env;
107 struct perf_bpil *info_linear;
108 int id = event->bpf.id;
109 unsigned int i;
110
111 /* perf-record, no need to handle bpf-event */
112 if (env == NULL)
113 return 0;
114
115 info_node = perf_env__find_bpf_prog_info(env, id);
116 if (!info_node)
117 return 0;
118 info_linear = info_node->info_linear;
119
120 for (i = 0; i < info_linear->info.nr_jited_ksyms; i++) {
121 u64 *addrs = (u64 *)(uintptr_t)(info_linear->info.jited_ksyms);
122 u64 addr = addrs[i];
123 struct map *map = maps__find(machine__kernel_maps(machine), addr);
124
125 if (map) {
126 map->dso->binary_type = DSO_BINARY_TYPE__BPF_PROG_INFO;
127 map->dso->bpf_prog.id = id;
128 map->dso->bpf_prog.sub_id = i;
129 map->dso->bpf_prog.env = env;
130 }
131 }
132 return 0;
133}
134
135int machine__process_bpf(struct machine *machine, union perf_event *event,
136 struct perf_sample *sample)
137{
138 if (dump_trace)
139 perf_event__fprintf_bpf(event, stdout);
140
141 switch (event->bpf.type) {
142 case PERF_BPF_EVENT_PROG_LOAD:
143 return machine__process_bpf_event_load(machine, event, sample);
144
145 case PERF_BPF_EVENT_PROG_UNLOAD:
146 /*
147 * Do not free bpf_prog_info and btf of the program here,
148 * as annotation still need them. They will be freed at
149 * the end of the session.
150 */
151 break;
152 default:
153 pr_debug("unexpected bpf event type of %d\n", event->bpf.type);
154 break;
155 }
156 return 0;
157}
158
159static int perf_env__fetch_btf(struct perf_env *env,
160 u32 btf_id,
161 struct btf *btf)
162{
163 struct btf_node *node;
164 u32 data_size;
165 const void *data;
166
167 data = btf__raw_data(btf, &data_size);
168
169 node = malloc(data_size + sizeof(struct btf_node));
170 if (!node)
171 return -1;
172
173 node->id = btf_id;
174 node->data_size = data_size;
175 memcpy(node->data, data, data_size);
176
177 if (!perf_env__insert_btf(env, node)) {
178 /* Insertion failed because of a duplicate. */
179 free(node);
180 return -1;
181 }
182 return 0;
183}
184
185static int synthesize_bpf_prog_name(char *buf, int size,
186 struct bpf_prog_info *info,
187 struct btf *btf,
188 u32 sub_id)
189{
190 u8 (*prog_tags)[BPF_TAG_SIZE] = (void *)(uintptr_t)(info->prog_tags);
191 void *func_infos = (void *)(uintptr_t)(info->func_info);
192 u32 sub_prog_cnt = info->nr_jited_ksyms;
193 const struct bpf_func_info *finfo;
194 const char *short_name = NULL;
195 const struct btf_type *t;
196 int name_len;
197
198 name_len = snprintf(buf, size, "bpf_prog_");
199 name_len += snprintf_hex(buf + name_len, size - name_len,
200 prog_tags[sub_id], BPF_TAG_SIZE);
201 if (btf) {
202 finfo = func_infos + sub_id * info->func_info_rec_size;
203 t = btf__type_by_id(btf, finfo->type_id);
204 short_name = btf__name_by_offset(btf, t->name_off);
205 } else if (sub_id == 0 && sub_prog_cnt == 1) {
206 /* no subprog */
207 if (info->name[0])
208 short_name = info->name;
209 } else
210 short_name = "F";
211 if (short_name)
212 name_len += snprintf(buf + name_len, size - name_len,
213 "_%s", short_name);
214 return name_len;
215}
216
217/*
218 * Synthesize PERF_RECORD_KSYMBOL and PERF_RECORD_BPF_EVENT for one bpf
219 * program. One PERF_RECORD_BPF_EVENT is generated for the program. And
220 * one PERF_RECORD_KSYMBOL is generated for each sub program.
221 *
222 * Returns:
223 * 0 for success;
224 * -1 for failures;
225 * -2 for lack of kernel support.
226 */
227static int perf_event__synthesize_one_bpf_prog(struct perf_session *session,
228 perf_event__handler_t process,
229 struct machine *machine,
230 int fd,
231 union perf_event *event,
232 struct record_opts *opts)
233{
234 struct perf_record_ksymbol *ksymbol_event = &event->ksymbol;
235 struct perf_record_bpf_event *bpf_event = &event->bpf;
236 struct perf_tool *tool = session->tool;
237 struct bpf_prog_info_node *info_node;
238 struct perf_bpil *info_linear;
239 struct bpf_prog_info *info;
240 struct btf *btf = NULL;
241 struct perf_env *env;
242 u32 sub_prog_cnt, i;
243 int err = 0;
244 u64 arrays;
245
246 /*
247 * for perf-record and perf-report use header.env;
248 * otherwise, use global perf_env.
249 */
250 env = session->data ? &session->header.env : &perf_env;
251
252 arrays = 1UL << PERF_BPIL_JITED_KSYMS;
253 arrays |= 1UL << PERF_BPIL_JITED_FUNC_LENS;
254 arrays |= 1UL << PERF_BPIL_FUNC_INFO;
255 arrays |= 1UL << PERF_BPIL_PROG_TAGS;
256 arrays |= 1UL << PERF_BPIL_JITED_INSNS;
257 arrays |= 1UL << PERF_BPIL_LINE_INFO;
258 arrays |= 1UL << PERF_BPIL_JITED_LINE_INFO;
259
260 info_linear = get_bpf_prog_info_linear(fd, arrays);
261 if (IS_ERR_OR_NULL(info_linear)) {
262 info_linear = NULL;
263 pr_debug("%s: failed to get BPF program info. aborting\n", __func__);
264 return -1;
265 }
266
267 if (info_linear->info_len < offsetof(struct bpf_prog_info, prog_tags)) {
268 free(info_linear);
269 pr_debug("%s: the kernel is too old, aborting\n", __func__);
270 return -2;
271 }
272
273 info = &info_linear->info;
274 if (!info->jited_ksyms) {
275 free(info_linear);
276 return -1;
277 }
278
279 /* number of ksyms, func_lengths, and tags should match */
280 sub_prog_cnt = info->nr_jited_ksyms;
281 if (sub_prog_cnt != info->nr_prog_tags ||
282 sub_prog_cnt != info->nr_jited_func_lens) {
283 free(info_linear);
284 return -1;
285 }
286
287 /* check BTF func info support */
288 if (info->btf_id && info->nr_func_info && info->func_info_rec_size) {
289 /* btf func info number should be same as sub_prog_cnt */
290 if (sub_prog_cnt != info->nr_func_info) {
291 pr_debug("%s: mismatch in BPF sub program count and BTF function info count, aborting\n", __func__);
292 free(info_linear);
293 return -1;
294 }
295 btf = btf__load_from_kernel_by_id(info->btf_id);
296 if (libbpf_get_error(btf)) {
297 pr_debug("%s: failed to get BTF of id %u, aborting\n", __func__, info->btf_id);
298 err = -1;
299 goto out;
300 }
301 perf_env__fetch_btf(env, info->btf_id, btf);
302 }
303
304 /* Synthesize PERF_RECORD_KSYMBOL */
305 for (i = 0; i < sub_prog_cnt; i++) {
306 __u32 *prog_lens = (__u32 *)(uintptr_t)(info->jited_func_lens);
307 __u64 *prog_addrs = (__u64 *)(uintptr_t)(info->jited_ksyms);
308 int name_len;
309
310 *ksymbol_event = (struct perf_record_ksymbol) {
311 .header = {
312 .type = PERF_RECORD_KSYMBOL,
313 .size = offsetof(struct perf_record_ksymbol, name),
314 },
315 .addr = prog_addrs[i],
316 .len = prog_lens[i],
317 .ksym_type = PERF_RECORD_KSYMBOL_TYPE_BPF,
318 .flags = 0,
319 };
320
321 name_len = synthesize_bpf_prog_name(ksymbol_event->name,
322 KSYM_NAME_LEN, info, btf, i);
323 ksymbol_event->header.size += PERF_ALIGN(name_len + 1,
324 sizeof(u64));
325
326 memset((void *)event + event->header.size, 0, machine->id_hdr_size);
327 event->header.size += machine->id_hdr_size;
328 err = perf_tool__process_synth_event(tool, event,
329 machine, process);
330 }
331
332 if (!opts->no_bpf_event) {
333 /* Synthesize PERF_RECORD_BPF_EVENT */
334 *bpf_event = (struct perf_record_bpf_event) {
335 .header = {
336 .type = PERF_RECORD_BPF_EVENT,
337 .size = sizeof(struct perf_record_bpf_event),
338 },
339 .type = PERF_BPF_EVENT_PROG_LOAD,
340 .flags = 0,
341 .id = info->id,
342 };
343 memcpy(bpf_event->tag, info->tag, BPF_TAG_SIZE);
344 memset((void *)event + event->header.size, 0, machine->id_hdr_size);
345 event->header.size += machine->id_hdr_size;
346
347 /* save bpf_prog_info to env */
348 info_node = malloc(sizeof(struct bpf_prog_info_node));
349 if (!info_node) {
350 err = -1;
351 goto out;
352 }
353
354 info_node->info_linear = info_linear;
355 perf_env__insert_bpf_prog_info(env, info_node);
356 info_linear = NULL;
357
358 /*
359 * process after saving bpf_prog_info to env, so that
360 * required information is ready for look up
361 */
362 err = perf_tool__process_synth_event(tool, event,
363 machine, process);
364 }
365
366out:
367 free(info_linear);
368 btf__free(btf);
369 return err ? -1 : 0;
370}
371
372struct kallsyms_parse {
373 union perf_event *event;
374 perf_event__handler_t process;
375 struct machine *machine;
376 struct perf_tool *tool;
377};
378
379static int
380process_bpf_image(char *name, u64 addr, struct kallsyms_parse *data)
381{
382 struct machine *machine = data->machine;
383 union perf_event *event = data->event;
384 struct perf_record_ksymbol *ksymbol;
385 int len;
386
387 ksymbol = &event->ksymbol;
388
389 *ksymbol = (struct perf_record_ksymbol) {
390 .header = {
391 .type = PERF_RECORD_KSYMBOL,
392 .size = offsetof(struct perf_record_ksymbol, name),
393 },
394 .addr = addr,
395 .len = page_size,
396 .ksym_type = PERF_RECORD_KSYMBOL_TYPE_BPF,
397 .flags = 0,
398 };
399
400 len = scnprintf(ksymbol->name, KSYM_NAME_LEN, "%s", name);
401 ksymbol->header.size += PERF_ALIGN(len + 1, sizeof(u64));
402 memset((void *) event + event->header.size, 0, machine->id_hdr_size);
403 event->header.size += machine->id_hdr_size;
404
405 return perf_tool__process_synth_event(data->tool, event, machine,
406 data->process);
407}
408
409static int
410kallsyms_process_symbol(void *data, const char *_name,
411 char type __maybe_unused, u64 start)
412{
413 char disp[KSYM_NAME_LEN];
414 char *module, *name;
415 unsigned long id;
416 int err = 0;
417
418 module = strchr(_name, '\t');
419 if (!module)
420 return 0;
421
422 /* We are going after [bpf] module ... */
423 if (strcmp(module + 1, "[bpf]"))
424 return 0;
425
426 name = memdup(_name, (module - _name) + 1);
427 if (!name)
428 return -ENOMEM;
429
430 name[module - _name] = 0;
431
432 /* .. and only for trampolines and dispatchers */
433 if ((sscanf(name, "bpf_trampoline_%lu", &id) == 1) ||
434 (sscanf(name, "bpf_dispatcher_%s", disp) == 1))
435 err = process_bpf_image(name, start, data);
436
437 free(name);
438 return err;
439}
440
441int perf_event__synthesize_bpf_events(struct perf_session *session,
442 perf_event__handler_t process,
443 struct machine *machine,
444 struct record_opts *opts)
445{
446 const char *kallsyms_filename = "/proc/kallsyms";
447 struct kallsyms_parse arg;
448 union perf_event *event;
449 __u32 id = 0;
450 int err;
451 int fd;
452
453 event = malloc(sizeof(event->bpf) + KSYM_NAME_LEN + machine->id_hdr_size);
454 if (!event)
455 return -1;
456
457 /* Synthesize all the bpf programs in system. */
458 while (true) {
459 err = bpf_prog_get_next_id(id, &id);
460 if (err) {
461 if (errno == ENOENT) {
462 err = 0;
463 break;
464 }
465 pr_debug("%s: can't get next program: %s%s\n",
466 __func__, strerror(errno),
467 errno == EINVAL ? " -- kernel too old?" : "");
468 /* don't report error on old kernel or EPERM */
469 err = (errno == EINVAL || errno == EPERM) ? 0 : -1;
470 break;
471 }
472 fd = bpf_prog_get_fd_by_id(id);
473 if (fd < 0) {
474 pr_debug("%s: failed to get fd for prog_id %u\n",
475 __func__, id);
476 continue;
477 }
478
479 err = perf_event__synthesize_one_bpf_prog(session, process,
480 machine, fd,
481 event, opts);
482 close(fd);
483 if (err) {
484 /* do not return error for old kernel */
485 if (err == -2)
486 err = 0;
487 break;
488 }
489 }
490
491 /* Synthesize all the bpf images - trampolines/dispatchers. */
492 if (symbol_conf.kallsyms_name != NULL)
493 kallsyms_filename = symbol_conf.kallsyms_name;
494
495 arg = (struct kallsyms_parse) {
496 .event = event,
497 .process = process,
498 .machine = machine,
499 .tool = session->tool,
500 };
501
502 if (kallsyms__parse(kallsyms_filename, &arg, kallsyms_process_symbol)) {
503 pr_err("%s: failed to synthesize bpf images: %s\n",
504 __func__, strerror(errno));
505 }
506
507 free(event);
508 return err;
509}
510
511static void perf_env__add_bpf_info(struct perf_env *env, u32 id)
512{
513 struct bpf_prog_info_node *info_node;
514 struct perf_bpil *info_linear;
515 struct btf *btf = NULL;
516 u64 arrays;
517 u32 btf_id;
518 int fd;
519
520 fd = bpf_prog_get_fd_by_id(id);
521 if (fd < 0)
522 return;
523
524 arrays = 1UL << PERF_BPIL_JITED_KSYMS;
525 arrays |= 1UL << PERF_BPIL_JITED_FUNC_LENS;
526 arrays |= 1UL << PERF_BPIL_FUNC_INFO;
527 arrays |= 1UL << PERF_BPIL_PROG_TAGS;
528 arrays |= 1UL << PERF_BPIL_JITED_INSNS;
529 arrays |= 1UL << PERF_BPIL_LINE_INFO;
530 arrays |= 1UL << PERF_BPIL_JITED_LINE_INFO;
531
532 info_linear = get_bpf_prog_info_linear(fd, arrays);
533 if (IS_ERR_OR_NULL(info_linear)) {
534 pr_debug("%s: failed to get BPF program info. aborting\n", __func__);
535 goto out;
536 }
537
538 btf_id = info_linear->info.btf_id;
539
540 info_node = malloc(sizeof(struct bpf_prog_info_node));
541 if (info_node) {
542 info_node->info_linear = info_linear;
543 perf_env__insert_bpf_prog_info(env, info_node);
544 } else
545 free(info_linear);
546
547 if (btf_id == 0)
548 goto out;
549
550 btf = btf__load_from_kernel_by_id(btf_id);
551 if (libbpf_get_error(btf)) {
552 pr_debug("%s: failed to get BTF of id %u, aborting\n",
553 __func__, btf_id);
554 goto out;
555 }
556 perf_env__fetch_btf(env, btf_id, btf);
557
558out:
559 btf__free(btf);
560 close(fd);
561}
562
563static int bpf_event__sb_cb(union perf_event *event, void *data)
564{
565 struct perf_env *env = data;
566
567 if (event->header.type != PERF_RECORD_BPF_EVENT)
568 return -1;
569
570 switch (event->bpf.type) {
571 case PERF_BPF_EVENT_PROG_LOAD:
572 perf_env__add_bpf_info(env, event->bpf.id);
573
574 case PERF_BPF_EVENT_PROG_UNLOAD:
575 /*
576 * Do not free bpf_prog_info and btf of the program here,
577 * as annotation still need them. They will be freed at
578 * the end of the session.
579 */
580 break;
581 default:
582 pr_debug("unexpected bpf event type of %d\n", event->bpf.type);
583 break;
584 }
585
586 return 0;
587}
588
589int evlist__add_bpf_sb_event(struct evlist *evlist, struct perf_env *env)
590{
591 struct perf_event_attr attr = {
592 .type = PERF_TYPE_SOFTWARE,
593 .config = PERF_COUNT_SW_DUMMY,
594 .sample_id_all = 1,
595 .watermark = 1,
596 .bpf_event = 1,
597 .size = sizeof(attr), /* to capture ABI version */
598 };
599
600 /*
601 * Older gcc versions don't support designated initializers, like above,
602 * for unnamed union members, such as the following:
603 */
604 attr.wakeup_watermark = 1;
605
606 return evlist__add_sb_event(evlist, &attr, bpf_event__sb_cb, env);
607}
608
609void bpf_event__print_bpf_prog_info(struct bpf_prog_info *info,
610 struct perf_env *env,
611 FILE *fp)
612{
613 __u32 *prog_lens = (__u32 *)(uintptr_t)(info->jited_func_lens);
614 __u64 *prog_addrs = (__u64 *)(uintptr_t)(info->jited_ksyms);
615 char name[KSYM_NAME_LEN];
616 struct btf *btf = NULL;
617 u32 sub_prog_cnt, i;
618
619 sub_prog_cnt = info->nr_jited_ksyms;
620 if (sub_prog_cnt != info->nr_prog_tags ||
621 sub_prog_cnt != info->nr_jited_func_lens)
622 return;
623
624 if (info->btf_id) {
625 struct btf_node *node;
626
627 node = perf_env__find_btf(env, info->btf_id);
628 if (node)
629 btf = btf__new((__u8 *)(node->data),
630 node->data_size);
631 }
632
633 if (sub_prog_cnt == 1) {
634 synthesize_bpf_prog_name(name, KSYM_NAME_LEN, info, btf, 0);
635 fprintf(fp, "# bpf_prog_info %u: %s addr 0x%llx size %u\n",
636 info->id, name, prog_addrs[0], prog_lens[0]);
637 goto out;
638 }
639
640 fprintf(fp, "# bpf_prog_info %u:\n", info->id);
641 for (i = 0; i < sub_prog_cnt; i++) {
642 synthesize_bpf_prog_name(name, KSYM_NAME_LEN, info, btf, i);
643
644 fprintf(fp, "# \tsub_prog %u: %s addr 0x%llx size %u\n",
645 i, name, prog_addrs[i], prog_lens[i]);
646 }
647out:
648 btf__free(btf);
649}
1// SPDX-License-Identifier: GPL-2.0
2#include <errno.h>
3#include <stdlib.h>
4#include <bpf/bpf.h>
5#include <bpf/btf.h>
6#include <bpf/libbpf.h>
7#include <linux/btf.h>
8#include <linux/err.h>
9#include "bpf-event.h"
10#include "debug.h"
11#include "dso.h"
12#include "symbol.h"
13#include "machine.h"
14#include "env.h"
15#include "session.h"
16#include "map.h"
17#include "evlist.h"
18#include "record.h"
19#include "util/synthetic-events.h"
20
21#define ptr_to_u64(ptr) ((__u64)(unsigned long)(ptr))
22
23static int snprintf_hex(char *buf, size_t size, unsigned char *data, size_t len)
24{
25 int ret = 0;
26 size_t i;
27
28 for (i = 0; i < len; i++)
29 ret += snprintf(buf + ret, size - ret, "%02x", data[i]);
30 return ret;
31}
32
33static int machine__process_bpf_event_load(struct machine *machine,
34 union perf_event *event,
35 struct perf_sample *sample __maybe_unused)
36{
37 struct bpf_prog_info_linear *info_linear;
38 struct bpf_prog_info_node *info_node;
39 struct perf_env *env = machine->env;
40 int id = event->bpf.id;
41 unsigned int i;
42
43 /* perf-record, no need to handle bpf-event */
44 if (env == NULL)
45 return 0;
46
47 info_node = perf_env__find_bpf_prog_info(env, id);
48 if (!info_node)
49 return 0;
50 info_linear = info_node->info_linear;
51
52 for (i = 0; i < info_linear->info.nr_jited_ksyms; i++) {
53 u64 *addrs = (u64 *)(uintptr_t)(info_linear->info.jited_ksyms);
54 u64 addr = addrs[i];
55 struct map *map;
56
57 map = map_groups__find(&machine->kmaps, addr);
58
59 if (map) {
60 map->dso->binary_type = DSO_BINARY_TYPE__BPF_PROG_INFO;
61 map->dso->bpf_prog.id = id;
62 map->dso->bpf_prog.sub_id = i;
63 map->dso->bpf_prog.env = env;
64 }
65 }
66 return 0;
67}
68
69int machine__process_bpf(struct machine *machine, union perf_event *event,
70 struct perf_sample *sample)
71{
72 if (dump_trace)
73 perf_event__fprintf_bpf(event, stdout);
74
75 switch (event->bpf.type) {
76 case PERF_BPF_EVENT_PROG_LOAD:
77 return machine__process_bpf_event_load(machine, event, sample);
78
79 case PERF_BPF_EVENT_PROG_UNLOAD:
80 /*
81 * Do not free bpf_prog_info and btf of the program here,
82 * as annotation still need them. They will be freed at
83 * the end of the session.
84 */
85 break;
86 default:
87 pr_debug("unexpected bpf event type of %d\n", event->bpf.type);
88 break;
89 }
90 return 0;
91}
92
93static int perf_env__fetch_btf(struct perf_env *env,
94 u32 btf_id,
95 struct btf *btf)
96{
97 struct btf_node *node;
98 u32 data_size;
99 const void *data;
100
101 data = btf__get_raw_data(btf, &data_size);
102
103 node = malloc(data_size + sizeof(struct btf_node));
104 if (!node)
105 return -1;
106
107 node->id = btf_id;
108 node->data_size = data_size;
109 memcpy(node->data, data, data_size);
110
111 perf_env__insert_btf(env, node);
112 return 0;
113}
114
115static int synthesize_bpf_prog_name(char *buf, int size,
116 struct bpf_prog_info *info,
117 struct btf *btf,
118 u32 sub_id)
119{
120 u8 (*prog_tags)[BPF_TAG_SIZE] = (void *)(uintptr_t)(info->prog_tags);
121 void *func_infos = (void *)(uintptr_t)(info->func_info);
122 u32 sub_prog_cnt = info->nr_jited_ksyms;
123 const struct bpf_func_info *finfo;
124 const char *short_name = NULL;
125 const struct btf_type *t;
126 int name_len;
127
128 name_len = snprintf(buf, size, "bpf_prog_");
129 name_len += snprintf_hex(buf + name_len, size - name_len,
130 prog_tags[sub_id], BPF_TAG_SIZE);
131 if (btf) {
132 finfo = func_infos + sub_id * info->func_info_rec_size;
133 t = btf__type_by_id(btf, finfo->type_id);
134 short_name = btf__name_by_offset(btf, t->name_off);
135 } else if (sub_id == 0 && sub_prog_cnt == 1) {
136 /* no subprog */
137 if (info->name[0])
138 short_name = info->name;
139 } else
140 short_name = "F";
141 if (short_name)
142 name_len += snprintf(buf + name_len, size - name_len,
143 "_%s", short_name);
144 return name_len;
145}
146
147/*
148 * Synthesize PERF_RECORD_KSYMBOL and PERF_RECORD_BPF_EVENT for one bpf
149 * program. One PERF_RECORD_BPF_EVENT is generated for the program. And
150 * one PERF_RECORD_KSYMBOL is generated for each sub program.
151 *
152 * Returns:
153 * 0 for success;
154 * -1 for failures;
155 * -2 for lack of kernel support.
156 */
157static int perf_event__synthesize_one_bpf_prog(struct perf_session *session,
158 perf_event__handler_t process,
159 struct machine *machine,
160 int fd,
161 union perf_event *event,
162 struct record_opts *opts)
163{
164 struct perf_record_ksymbol *ksymbol_event = &event->ksymbol;
165 struct perf_record_bpf_event *bpf_event = &event->bpf;
166 struct bpf_prog_info_linear *info_linear;
167 struct perf_tool *tool = session->tool;
168 struct bpf_prog_info_node *info_node;
169 struct bpf_prog_info *info;
170 struct btf *btf = NULL;
171 struct perf_env *env;
172 u32 sub_prog_cnt, i;
173 int err = 0;
174 u64 arrays;
175
176 /*
177 * for perf-record and perf-report use header.env;
178 * otherwise, use global perf_env.
179 */
180 env = session->data ? &session->header.env : &perf_env;
181
182 arrays = 1UL << BPF_PROG_INFO_JITED_KSYMS;
183 arrays |= 1UL << BPF_PROG_INFO_JITED_FUNC_LENS;
184 arrays |= 1UL << BPF_PROG_INFO_FUNC_INFO;
185 arrays |= 1UL << BPF_PROG_INFO_PROG_TAGS;
186 arrays |= 1UL << BPF_PROG_INFO_JITED_INSNS;
187 arrays |= 1UL << BPF_PROG_INFO_LINE_INFO;
188 arrays |= 1UL << BPF_PROG_INFO_JITED_LINE_INFO;
189
190 info_linear = bpf_program__get_prog_info_linear(fd, arrays);
191 if (IS_ERR_OR_NULL(info_linear)) {
192 info_linear = NULL;
193 pr_debug("%s: failed to get BPF program info. aborting\n", __func__);
194 return -1;
195 }
196
197 if (info_linear->info_len < offsetof(struct bpf_prog_info, prog_tags)) {
198 pr_debug("%s: the kernel is too old, aborting\n", __func__);
199 return -2;
200 }
201
202 info = &info_linear->info;
203
204 /* number of ksyms, func_lengths, and tags should match */
205 sub_prog_cnt = info->nr_jited_ksyms;
206 if (sub_prog_cnt != info->nr_prog_tags ||
207 sub_prog_cnt != info->nr_jited_func_lens)
208 return -1;
209
210 /* check BTF func info support */
211 if (info->btf_id && info->nr_func_info && info->func_info_rec_size) {
212 /* btf func info number should be same as sub_prog_cnt */
213 if (sub_prog_cnt != info->nr_func_info) {
214 pr_debug("%s: mismatch in BPF sub program count and BTF function info count, aborting\n", __func__);
215 err = -1;
216 goto out;
217 }
218 if (btf__get_from_id(info->btf_id, &btf)) {
219 pr_debug("%s: failed to get BTF of id %u, aborting\n", __func__, info->btf_id);
220 err = -1;
221 btf = NULL;
222 goto out;
223 }
224 perf_env__fetch_btf(env, info->btf_id, btf);
225 }
226
227 /* Synthesize PERF_RECORD_KSYMBOL */
228 for (i = 0; i < sub_prog_cnt; i++) {
229 __u32 *prog_lens = (__u32 *)(uintptr_t)(info->jited_func_lens);
230 __u64 *prog_addrs = (__u64 *)(uintptr_t)(info->jited_ksyms);
231 int name_len;
232
233 *ksymbol_event = (struct perf_record_ksymbol) {
234 .header = {
235 .type = PERF_RECORD_KSYMBOL,
236 .size = offsetof(struct perf_record_ksymbol, name),
237 },
238 .addr = prog_addrs[i],
239 .len = prog_lens[i],
240 .ksym_type = PERF_RECORD_KSYMBOL_TYPE_BPF,
241 .flags = 0,
242 };
243
244 name_len = synthesize_bpf_prog_name(ksymbol_event->name,
245 KSYM_NAME_LEN, info, btf, i);
246 ksymbol_event->header.size += PERF_ALIGN(name_len + 1,
247 sizeof(u64));
248
249 memset((void *)event + event->header.size, 0, machine->id_hdr_size);
250 event->header.size += machine->id_hdr_size;
251 err = perf_tool__process_synth_event(tool, event,
252 machine, process);
253 }
254
255 if (!opts->no_bpf_event) {
256 /* Synthesize PERF_RECORD_BPF_EVENT */
257 *bpf_event = (struct perf_record_bpf_event) {
258 .header = {
259 .type = PERF_RECORD_BPF_EVENT,
260 .size = sizeof(struct perf_record_bpf_event),
261 },
262 .type = PERF_BPF_EVENT_PROG_LOAD,
263 .flags = 0,
264 .id = info->id,
265 };
266 memcpy(bpf_event->tag, info->tag, BPF_TAG_SIZE);
267 memset((void *)event + event->header.size, 0, machine->id_hdr_size);
268 event->header.size += machine->id_hdr_size;
269
270 /* save bpf_prog_info to env */
271 info_node = malloc(sizeof(struct bpf_prog_info_node));
272 if (!info_node) {
273 err = -1;
274 goto out;
275 }
276
277 info_node->info_linear = info_linear;
278 perf_env__insert_bpf_prog_info(env, info_node);
279 info_linear = NULL;
280
281 /*
282 * process after saving bpf_prog_info to env, so that
283 * required information is ready for look up
284 */
285 err = perf_tool__process_synth_event(tool, event,
286 machine, process);
287 }
288
289out:
290 free(info_linear);
291 free(btf);
292 return err ? -1 : 0;
293}
294
295int perf_event__synthesize_bpf_events(struct perf_session *session,
296 perf_event__handler_t process,
297 struct machine *machine,
298 struct record_opts *opts)
299{
300 union perf_event *event;
301 __u32 id = 0;
302 int err;
303 int fd;
304
305 event = malloc(sizeof(event->bpf) + KSYM_NAME_LEN + machine->id_hdr_size);
306 if (!event)
307 return -1;
308 while (true) {
309 err = bpf_prog_get_next_id(id, &id);
310 if (err) {
311 if (errno == ENOENT) {
312 err = 0;
313 break;
314 }
315 pr_debug("%s: can't get next program: %s%s\n",
316 __func__, strerror(errno),
317 errno == EINVAL ? " -- kernel too old?" : "");
318 /* don't report error on old kernel or EPERM */
319 err = (errno == EINVAL || errno == EPERM) ? 0 : -1;
320 break;
321 }
322 fd = bpf_prog_get_fd_by_id(id);
323 if (fd < 0) {
324 pr_debug("%s: failed to get fd for prog_id %u\n",
325 __func__, id);
326 continue;
327 }
328
329 err = perf_event__synthesize_one_bpf_prog(session, process,
330 machine, fd,
331 event, opts);
332 close(fd);
333 if (err) {
334 /* do not return error for old kernel */
335 if (err == -2)
336 err = 0;
337 break;
338 }
339 }
340 free(event);
341 return err;
342}
343
344static void perf_env__add_bpf_info(struct perf_env *env, u32 id)
345{
346 struct bpf_prog_info_linear *info_linear;
347 struct bpf_prog_info_node *info_node;
348 struct btf *btf = NULL;
349 u64 arrays;
350 u32 btf_id;
351 int fd;
352
353 fd = bpf_prog_get_fd_by_id(id);
354 if (fd < 0)
355 return;
356
357 arrays = 1UL << BPF_PROG_INFO_JITED_KSYMS;
358 arrays |= 1UL << BPF_PROG_INFO_JITED_FUNC_LENS;
359 arrays |= 1UL << BPF_PROG_INFO_FUNC_INFO;
360 arrays |= 1UL << BPF_PROG_INFO_PROG_TAGS;
361 arrays |= 1UL << BPF_PROG_INFO_JITED_INSNS;
362 arrays |= 1UL << BPF_PROG_INFO_LINE_INFO;
363 arrays |= 1UL << BPF_PROG_INFO_JITED_LINE_INFO;
364
365 info_linear = bpf_program__get_prog_info_linear(fd, arrays);
366 if (IS_ERR_OR_NULL(info_linear)) {
367 pr_debug("%s: failed to get BPF program info. aborting\n", __func__);
368 goto out;
369 }
370
371 btf_id = info_linear->info.btf_id;
372
373 info_node = malloc(sizeof(struct bpf_prog_info_node));
374 if (info_node) {
375 info_node->info_linear = info_linear;
376 perf_env__insert_bpf_prog_info(env, info_node);
377 } else
378 free(info_linear);
379
380 if (btf_id == 0)
381 goto out;
382
383 if (btf__get_from_id(btf_id, &btf)) {
384 pr_debug("%s: failed to get BTF of id %u, aborting\n",
385 __func__, btf_id);
386 goto out;
387 }
388 perf_env__fetch_btf(env, btf_id, btf);
389
390out:
391 free(btf);
392 close(fd);
393}
394
395static int bpf_event__sb_cb(union perf_event *event, void *data)
396{
397 struct perf_env *env = data;
398
399 if (event->header.type != PERF_RECORD_BPF_EVENT)
400 return -1;
401
402 switch (event->bpf.type) {
403 case PERF_BPF_EVENT_PROG_LOAD:
404 perf_env__add_bpf_info(env, event->bpf.id);
405
406 case PERF_BPF_EVENT_PROG_UNLOAD:
407 /*
408 * Do not free bpf_prog_info and btf of the program here,
409 * as annotation still need them. They will be freed at
410 * the end of the session.
411 */
412 break;
413 default:
414 pr_debug("unexpected bpf event type of %d\n", event->bpf.type);
415 break;
416 }
417
418 return 0;
419}
420
421int bpf_event__add_sb_event(struct evlist **evlist,
422 struct perf_env *env)
423{
424 struct perf_event_attr attr = {
425 .type = PERF_TYPE_SOFTWARE,
426 .config = PERF_COUNT_SW_DUMMY,
427 .sample_id_all = 1,
428 .watermark = 1,
429 .bpf_event = 1,
430 .size = sizeof(attr), /* to capture ABI version */
431 };
432
433 /*
434 * Older gcc versions don't support designated initializers, like above,
435 * for unnamed union members, such as the following:
436 */
437 attr.wakeup_watermark = 1;
438
439 return perf_evlist__add_sb_event(evlist, &attr, bpf_event__sb_cb, env);
440}
441
442void bpf_event__print_bpf_prog_info(struct bpf_prog_info *info,
443 struct perf_env *env,
444 FILE *fp)
445{
446 __u32 *prog_lens = (__u32 *)(uintptr_t)(info->jited_func_lens);
447 __u64 *prog_addrs = (__u64 *)(uintptr_t)(info->jited_ksyms);
448 char name[KSYM_NAME_LEN];
449 struct btf *btf = NULL;
450 u32 sub_prog_cnt, i;
451
452 sub_prog_cnt = info->nr_jited_ksyms;
453 if (sub_prog_cnt != info->nr_prog_tags ||
454 sub_prog_cnt != info->nr_jited_func_lens)
455 return;
456
457 if (info->btf_id) {
458 struct btf_node *node;
459
460 node = perf_env__find_btf(env, info->btf_id);
461 if (node)
462 btf = btf__new((__u8 *)(node->data),
463 node->data_size);
464 }
465
466 if (sub_prog_cnt == 1) {
467 synthesize_bpf_prog_name(name, KSYM_NAME_LEN, info, btf, 0);
468 fprintf(fp, "# bpf_prog_info %u: %s addr 0x%llx size %u\n",
469 info->id, name, prog_addrs[0], prog_lens[0]);
470 return;
471 }
472
473 fprintf(fp, "# bpf_prog_info %u:\n", info->id);
474 for (i = 0; i < sub_prog_cnt; i++) {
475 synthesize_bpf_prog_name(name, KSYM_NAME_LEN, info, btf, i);
476
477 fprintf(fp, "# \tsub_prog %u: %s addr 0x%llx size %u\n",
478 i, name, prog_addrs[i], prog_lens[i]);
479 }
480}