1 // SPDX-License-Identifier: GPL-2.0
2 #include <errno.h>
3 #include <stddef.h>
4 #include <stdint.h>
5 #include <stdio.h>
6 #include <stdlib.h>
7 #include <string.h>
8 #include <bpf/bpf.h>
9 #include <bpf/btf.h>
10 #include <bpf/libbpf.h>
11 #include <linux/bpf.h>
12 #include <linux/btf.h>
13 #include <linux/err.h>
14 #include <linux/perf_event.h>
15 #include <linux/string.h>
16 #include <linux/zalloc.h>
17 #include <internal/lib.h>
18 #include <perf/event.h>
19 #include <symbol/kallsyms.h>
20 #include "bpf-event.h"
21 #include "bpf-utils.h"
22 #include "debug.h"
23 #include "dso.h"
24 #include "symbol.h"
25 #include "machine.h"
26 #include "env.h"
27 #include "session.h"
28 #include "map.h"
29 #include "evlist.h"
30 #include "record.h"
31 #include "util/synthetic-events.h"
32
snprintf_hex(char * buf,size_t size,unsigned char * data,size_t len)33 static int snprintf_hex(char *buf, size_t size, unsigned char *data, size_t len)
34 {
35 int ret = 0;
36 size_t i;
37
38 for (i = 0; i < len; i++)
39 ret += snprintf(buf + ret, size - ret, "%02x", data[i]);
40 return ret;
41 }
42
machine__process_bpf_event_load(struct machine * machine,union perf_event * event,struct perf_sample * sample __maybe_unused)43 static int machine__process_bpf_event_load(struct machine *machine,
44 union perf_event *event,
45 struct perf_sample *sample __maybe_unused)
46 {
47 struct bpf_prog_info_node *info_node;
48 struct perf_env *env = machine->env;
49 struct perf_bpil *info_linear;
50 int id = event->bpf.id;
51 unsigned int i;
52
53 /* perf-record, no need to handle bpf-event */
54 if (env == NULL)
55 return 0;
56
57 info_node = perf_env__find_bpf_prog_info(env, id);
58 if (!info_node)
59 return 0;
60 info_linear = info_node->info_linear;
61
62 for (i = 0; i < info_linear->info.nr_jited_ksyms; i++) {
63 u64 *addrs = (u64 *)(uintptr_t)(info_linear->info.jited_ksyms);
64 u64 addr = addrs[i];
65 struct map *map = maps__find(machine__kernel_maps(machine), addr);
66
67 if (map) {
68 struct dso *dso = map__dso(map);
69
70 dso__set_binary_type(dso, DSO_BINARY_TYPE__BPF_PROG_INFO);
71 dso__bpf_prog(dso)->id = id;
72 dso__bpf_prog(dso)->sub_id = i;
73 dso__bpf_prog(dso)->env = env;
74 map__put(map);
75 }
76 }
77 return 0;
78 }
79
machine__process_bpf(struct machine * machine,union perf_event * event,struct perf_sample * sample)80 int machine__process_bpf(struct machine *machine, union perf_event *event,
81 struct perf_sample *sample)
82 {
83 if (dump_trace)
84 perf_event__fprintf_bpf(event, stdout);
85
86 switch (event->bpf.type) {
87 case PERF_BPF_EVENT_PROG_LOAD:
88 return machine__process_bpf_event_load(machine, event, sample);
89
90 case PERF_BPF_EVENT_PROG_UNLOAD:
91 /*
92 * Do not free bpf_prog_info and btf of the program here,
93 * as annotation still need them. They will be freed at
94 * the end of the session.
95 */
96 break;
97 default:
98 pr_debug("unexpected bpf event type of %d\n", event->bpf.type);
99 break;
100 }
101 return 0;
102 }
103
perf_env__fetch_btf(struct perf_env * env,u32 btf_id,struct btf * btf)104 static int perf_env__fetch_btf(struct perf_env *env,
105 u32 btf_id,
106 struct btf *btf)
107 {
108 struct btf_node *node;
109 u32 data_size;
110 const void *data;
111
112 data = btf__raw_data(btf, &data_size);
113
114 node = malloc(data_size + sizeof(struct btf_node));
115 if (!node)
116 return -1;
117
118 node->id = btf_id;
119 node->data_size = data_size;
120 memcpy(node->data, data, data_size);
121
122 if (!perf_env__insert_btf(env, node)) {
123 /* Insertion failed because of a duplicate. */
124 free(node);
125 return -1;
126 }
127 return 0;
128 }
129
synthesize_bpf_prog_name(char * buf,int size,struct bpf_prog_info * info,struct btf * btf,u32 sub_id)130 static int synthesize_bpf_prog_name(char *buf, int size,
131 struct bpf_prog_info *info,
132 struct btf *btf,
133 u32 sub_id)
134 {
135 u8 (*prog_tags)[BPF_TAG_SIZE] = (void *)(uintptr_t)(info->prog_tags);
136 void *func_infos = (void *)(uintptr_t)(info->func_info);
137 u32 sub_prog_cnt = info->nr_jited_ksyms;
138 const struct bpf_func_info *finfo;
139 const char *short_name = NULL;
140 const struct btf_type *t;
141 int name_len;
142
143 name_len = snprintf(buf, size, "bpf_prog_");
144 name_len += snprintf_hex(buf + name_len, size - name_len,
145 prog_tags[sub_id], BPF_TAG_SIZE);
146 if (btf) {
147 finfo = func_infos + sub_id * info->func_info_rec_size;
148 t = btf__type_by_id(btf, finfo->type_id);
149 short_name = btf__name_by_offset(btf, t->name_off);
150 } else if (sub_id == 0 && sub_prog_cnt == 1) {
151 /* no subprog */
152 if (info->name[0])
153 short_name = info->name;
154 } else
155 short_name = "F";
156 if (short_name)
157 name_len += snprintf(buf + name_len, size - name_len,
158 "_%s", short_name);
159 return name_len;
160 }
161
162 #ifdef HAVE_LIBBPF_STRINGS_SUPPORT
163
164 #define BPF_METADATA_PREFIX "bpf_metadata_"
165 #define BPF_METADATA_PREFIX_LEN (sizeof(BPF_METADATA_PREFIX) - 1)
166
name_has_bpf_metadata_prefix(const char ** s)167 static bool name_has_bpf_metadata_prefix(const char **s)
168 {
169 if (strncmp(*s, BPF_METADATA_PREFIX, BPF_METADATA_PREFIX_LEN) != 0)
170 return false;
171 *s += BPF_METADATA_PREFIX_LEN;
172 return true;
173 }
174
175 struct bpf_metadata_map {
176 struct btf *btf;
177 const struct btf_type *datasec;
178 void *rodata;
179 size_t rodata_size;
180 unsigned int num_vars;
181 };
182
bpf_metadata_read_map_data(__u32 map_id,struct bpf_metadata_map * map)183 static int bpf_metadata_read_map_data(__u32 map_id, struct bpf_metadata_map *map)
184 {
185 int map_fd;
186 struct bpf_map_info map_info;
187 __u32 map_info_len;
188 int key;
189 struct btf *btf;
190 const struct btf_type *datasec;
191 struct btf_var_secinfo *vsi;
192 unsigned int vlen, vars;
193 void *rodata;
194
195 map_fd = bpf_map_get_fd_by_id(map_id);
196 if (map_fd < 0)
197 return -1;
198
199 memset(&map_info, 0, sizeof(map_info));
200 map_info_len = sizeof(map_info);
201 if (bpf_obj_get_info_by_fd(map_fd, &map_info, &map_info_len) < 0)
202 goto out_close;
203
204 /* If it's not an .rodata map, don't bother. */
205 if (map_info.type != BPF_MAP_TYPE_ARRAY ||
206 map_info.key_size != sizeof(int) ||
207 map_info.max_entries != 1 ||
208 !map_info.btf_value_type_id ||
209 !strstr(map_info.name, ".rodata")) {
210 goto out_close;
211 }
212
213 btf = btf__load_from_kernel_by_id(map_info.btf_id);
214 if (!btf)
215 goto out_close;
216 datasec = btf__type_by_id(btf, map_info.btf_value_type_id);
217 if (!btf_is_datasec(datasec))
218 goto out_free_btf;
219
220 /*
221 * If there aren't any variables with the "bpf_metadata_" prefix,
222 * don't bother.
223 */
224 vlen = btf_vlen(datasec);
225 vsi = btf_var_secinfos(datasec);
226 vars = 0;
227 for (unsigned int i = 0; i < vlen; i++, vsi++) {
228 const struct btf_type *t_var = btf__type_by_id(btf, vsi->type);
229 const char *name = btf__name_by_offset(btf, t_var->name_off);
230
231 if (name_has_bpf_metadata_prefix(&name))
232 vars++;
233 }
234 if (vars == 0)
235 goto out_free_btf;
236
237 rodata = zalloc(map_info.value_size);
238 if (!rodata)
239 goto out_free_btf;
240 key = 0;
241 if (bpf_map_lookup_elem(map_fd, &key, rodata)) {
242 free(rodata);
243 goto out_free_btf;
244 }
245 close(map_fd);
246
247 map->btf = btf;
248 map->datasec = datasec;
249 map->rodata = rodata;
250 map->rodata_size = map_info.value_size;
251 map->num_vars = vars;
252 return 0;
253
254 out_free_btf:
255 btf__free(btf);
256 out_close:
257 close(map_fd);
258 return -1;
259 }
260
261 struct format_btf_ctx {
262 char *buf;
263 size_t buf_size;
264 size_t buf_idx;
265 };
266
format_btf_cb(void * arg,const char * fmt,va_list ap)267 static void format_btf_cb(void *arg, const char *fmt, va_list ap)
268 {
269 int n;
270 struct format_btf_ctx *ctx = (struct format_btf_ctx *)arg;
271
272 n = vsnprintf(ctx->buf + ctx->buf_idx, ctx->buf_size - ctx->buf_idx,
273 fmt, ap);
274 ctx->buf_idx += n;
275 if (ctx->buf_idx >= ctx->buf_size)
276 ctx->buf_idx = ctx->buf_size;
277 }
278
format_btf_variable(struct btf * btf,char * buf,size_t buf_size,const struct btf_type * t,const void * btf_data)279 static void format_btf_variable(struct btf *btf, char *buf, size_t buf_size,
280 const struct btf_type *t, const void *btf_data)
281 {
282 struct format_btf_ctx ctx = {
283 .buf = buf,
284 .buf_idx = 0,
285 .buf_size = buf_size,
286 };
287 const struct btf_dump_type_data_opts opts = {
288 .sz = sizeof(struct btf_dump_type_data_opts),
289 .skip_names = 1,
290 .compact = 1,
291 .emit_strings = 1,
292 };
293 struct btf_dump *d;
294 size_t btf_size;
295
296 d = btf_dump__new(btf, format_btf_cb, &ctx, NULL);
297 btf_size = btf__resolve_size(btf, t->type);
298 btf_dump__dump_type_data(d, t->type, btf_data, btf_size, &opts);
299 btf_dump__free(d);
300 }
301
bpf_metadata_fill_event(struct bpf_metadata_map * map,struct perf_record_bpf_metadata * bpf_metadata_event)302 static void bpf_metadata_fill_event(struct bpf_metadata_map *map,
303 struct perf_record_bpf_metadata *bpf_metadata_event)
304 {
305 struct btf_var_secinfo *vsi;
306 unsigned int i, vlen;
307
308 memset(bpf_metadata_event->prog_name, 0, BPF_PROG_NAME_LEN);
309 vlen = btf_vlen(map->datasec);
310 vsi = btf_var_secinfos(map->datasec);
311
312 for (i = 0; i < vlen; i++, vsi++) {
313 const struct btf_type *t_var = btf__type_by_id(map->btf,
314 vsi->type);
315 const char *name = btf__name_by_offset(map->btf,
316 t_var->name_off);
317 const __u64 nr_entries = bpf_metadata_event->nr_entries;
318 struct perf_record_bpf_metadata_entry *entry;
319
320 if (!name_has_bpf_metadata_prefix(&name))
321 continue;
322
323 if (nr_entries >= (__u64)map->num_vars)
324 break;
325
326 entry = &bpf_metadata_event->entries[nr_entries];
327 memset(entry, 0, sizeof(*entry));
328 snprintf(entry->key, BPF_METADATA_KEY_LEN, "%s", name);
329 format_btf_variable(map->btf, entry->value,
330 BPF_METADATA_VALUE_LEN, t_var,
331 map->rodata + vsi->offset);
332 bpf_metadata_event->nr_entries++;
333 }
334 }
335
bpf_metadata_free_map_data(struct bpf_metadata_map * map)336 static void bpf_metadata_free_map_data(struct bpf_metadata_map *map)
337 {
338 btf__free(map->btf);
339 free(map->rodata);
340 }
341
bpf_metadata_alloc(__u32 nr_prog_tags,__u32 nr_variables)342 static struct bpf_metadata *bpf_metadata_alloc(__u32 nr_prog_tags,
343 __u32 nr_variables)
344 {
345 struct bpf_metadata *metadata;
346 size_t event_size;
347
348 metadata = zalloc(sizeof(struct bpf_metadata));
349 if (!metadata)
350 return NULL;
351
352 metadata->prog_names = zalloc(nr_prog_tags * sizeof(char *));
353 if (!metadata->prog_names) {
354 bpf_metadata_free(metadata);
355 return NULL;
356 }
357 for (__u32 prog_index = 0; prog_index < nr_prog_tags; prog_index++) {
358 metadata->prog_names[prog_index] = zalloc(BPF_PROG_NAME_LEN);
359 if (!metadata->prog_names[prog_index]) {
360 bpf_metadata_free(metadata);
361 return NULL;
362 }
363 metadata->nr_prog_names++;
364 }
365
366 event_size = sizeof(metadata->event->bpf_metadata) +
367 nr_variables * sizeof(metadata->event->bpf_metadata.entries[0]);
368 metadata->event = zalloc(event_size);
369 if (!metadata->event) {
370 bpf_metadata_free(metadata);
371 return NULL;
372 }
373 metadata->event->bpf_metadata = (struct perf_record_bpf_metadata) {
374 .header = {
375 .type = PERF_RECORD_BPF_METADATA,
376 .size = event_size,
377 },
378 .nr_entries = 0,
379 };
380
381 return metadata;
382 }
383
bpf_metadata_create(struct bpf_prog_info * info)384 static struct bpf_metadata *bpf_metadata_create(struct bpf_prog_info *info)
385 {
386 struct bpf_metadata *metadata;
387 const __u32 *map_ids = (__u32 *)(uintptr_t)info->map_ids;
388
389 for (__u32 map_index = 0; map_index < info->nr_map_ids; map_index++) {
390 struct bpf_metadata_map map;
391
392 if (bpf_metadata_read_map_data(map_ids[map_index], &map) != 0)
393 continue;
394
395 metadata = bpf_metadata_alloc(info->nr_prog_tags, map.num_vars);
396 if (!metadata)
397 continue;
398
399 bpf_metadata_fill_event(&map, &metadata->event->bpf_metadata);
400
401 for (__u32 index = 0; index < info->nr_prog_tags; index++) {
402 synthesize_bpf_prog_name(metadata->prog_names[index],
403 BPF_PROG_NAME_LEN, info,
404 map.btf, index);
405 }
406
407 bpf_metadata_free_map_data(&map);
408
409 return metadata;
410 }
411
412 return NULL;
413 }
414
synthesize_perf_record_bpf_metadata(const struct bpf_metadata * metadata,const struct perf_tool * tool,perf_event__handler_t process,struct machine * machine)415 static int synthesize_perf_record_bpf_metadata(const struct bpf_metadata *metadata,
416 const struct perf_tool *tool,
417 perf_event__handler_t process,
418 struct machine *machine)
419 {
420 const size_t event_size = metadata->event->header.size;
421 union perf_event *event;
422 int err = 0;
423
424 event = zalloc(event_size + machine->id_hdr_size);
425 if (!event)
426 return -1;
427 memcpy(event, metadata->event, event_size);
428 memset((void *)event + event->header.size, 0, machine->id_hdr_size);
429 event->header.size += machine->id_hdr_size;
430 for (__u32 index = 0; index < metadata->nr_prog_names; index++) {
431 memcpy(event->bpf_metadata.prog_name,
432 metadata->prog_names[index], BPF_PROG_NAME_LEN);
433 err = perf_tool__process_synth_event(tool, event, machine,
434 process);
435 if (err != 0)
436 break;
437 }
438
439 free(event);
440 return err;
441 }
442
bpf_metadata_free(struct bpf_metadata * metadata)443 void bpf_metadata_free(struct bpf_metadata *metadata)
444 {
445 if (metadata == NULL)
446 return;
447 for (__u32 index = 0; index < metadata->nr_prog_names; index++)
448 free(metadata->prog_names[index]);
449 free(metadata->prog_names);
450 free(metadata->event);
451 free(metadata);
452 }
453
454 #else /* HAVE_LIBBPF_STRINGS_SUPPORT */
455
bpf_metadata_create(struct bpf_prog_info * info __maybe_unused)456 static struct bpf_metadata *bpf_metadata_create(struct bpf_prog_info *info __maybe_unused)
457 {
458 return NULL;
459 }
460
synthesize_perf_record_bpf_metadata(const struct bpf_metadata * metadata __maybe_unused,const struct perf_tool * tool __maybe_unused,perf_event__handler_t process __maybe_unused,struct machine * machine __maybe_unused)461 static int synthesize_perf_record_bpf_metadata(const struct bpf_metadata *metadata __maybe_unused,
462 const struct perf_tool *tool __maybe_unused,
463 perf_event__handler_t process __maybe_unused,
464 struct machine *machine __maybe_unused)
465 {
466 return 0;
467 }
468
bpf_metadata_free(struct bpf_metadata * metadata __maybe_unused)469 void bpf_metadata_free(struct bpf_metadata *metadata __maybe_unused)
470 {
471 }
472
473 #endif /* HAVE_LIBBPF_STRINGS_SUPPORT */
474
475 struct bpf_metadata_final_ctx {
476 const struct perf_tool *tool;
477 perf_event__handler_t process;
478 struct machine *machine;
479 };
480
synthesize_final_bpf_metadata_cb(struct bpf_prog_info_node * node,void * data)481 static void synthesize_final_bpf_metadata_cb(struct bpf_prog_info_node *node,
482 void *data)
483 {
484 struct bpf_metadata_final_ctx *ctx = (struct bpf_metadata_final_ctx *)data;
485 struct bpf_metadata *metadata = node->metadata;
486 int err;
487
488 if (metadata == NULL)
489 return;
490 err = synthesize_perf_record_bpf_metadata(metadata, ctx->tool,
491 ctx->process, ctx->machine);
492 if (err != 0) {
493 const char *prog_name = metadata->prog_names[0];
494
495 if (prog_name != NULL)
496 pr_warning("Couldn't synthesize final BPF metadata for %s.\n", prog_name);
497 else
498 pr_warning("Couldn't synthesize final BPF metadata.\n");
499 }
500 bpf_metadata_free(metadata);
501 node->metadata = NULL;
502 }
503
perf_event__synthesize_final_bpf_metadata(struct perf_session * session,perf_event__handler_t process)504 void perf_event__synthesize_final_bpf_metadata(struct perf_session *session,
505 perf_event__handler_t process)
506 {
507 struct perf_env *env = &session->header.env;
508 struct bpf_metadata_final_ctx ctx = {
509 .tool = session->tool,
510 .process = process,
511 .machine = &session->machines.host,
512 };
513
514 perf_env__iterate_bpf_prog_info(env, synthesize_final_bpf_metadata_cb,
515 &ctx);
516 }
517
518 /*
519 * Synthesize PERF_RECORD_KSYMBOL and PERF_RECORD_BPF_EVENT for one bpf
520 * program. One PERF_RECORD_BPF_EVENT is generated for the program. And
521 * one PERF_RECORD_KSYMBOL is generated for each sub program.
522 *
523 * Returns:
524 * 0 for success;
525 * -1 for failures;
526 * -2 for lack of kernel support.
527 */
perf_event__synthesize_one_bpf_prog(struct perf_session * session,perf_event__handler_t process,struct machine * machine,int fd,union perf_event * event,struct record_opts * opts)528 static int perf_event__synthesize_one_bpf_prog(struct perf_session *session,
529 perf_event__handler_t process,
530 struct machine *machine,
531 int fd,
532 union perf_event *event,
533 struct record_opts *opts)
534 {
535 struct perf_record_ksymbol *ksymbol_event = &event->ksymbol;
536 struct perf_record_bpf_event *bpf_event = &event->bpf;
537 const struct perf_tool *tool = session->tool;
538 struct bpf_prog_info_node *info_node;
539 struct perf_bpil *info_linear;
540 struct bpf_metadata *metadata;
541 struct bpf_prog_info *info;
542 struct btf *btf = NULL;
543 struct perf_env *env;
544 u32 sub_prog_cnt, i;
545 int err = 0;
546 u64 arrays;
547
548 /*
549 * for perf-record and perf-report use header.env;
550 * otherwise, use global perf_env.
551 */
552 env = perf_session__env(session);
553
554 arrays = 1UL << PERF_BPIL_JITED_KSYMS;
555 arrays |= 1UL << PERF_BPIL_JITED_FUNC_LENS;
556 arrays |= 1UL << PERF_BPIL_FUNC_INFO;
557 arrays |= 1UL << PERF_BPIL_PROG_TAGS;
558 arrays |= 1UL << PERF_BPIL_JITED_INSNS;
559 arrays |= 1UL << PERF_BPIL_LINE_INFO;
560 arrays |= 1UL << PERF_BPIL_JITED_LINE_INFO;
561 arrays |= 1UL << PERF_BPIL_MAP_IDS;
562
563 info_linear = get_bpf_prog_info_linear(fd, arrays);
564 if (IS_ERR_OR_NULL(info_linear)) {
565 info_linear = NULL;
566 pr_debug("%s: failed to get BPF program info. aborting\n", __func__);
567 return -1;
568 }
569
570 if (info_linear->info_len < offsetof(struct bpf_prog_info, prog_tags)) {
571 free(info_linear);
572 pr_debug("%s: the kernel is too old, aborting\n", __func__);
573 return -2;
574 }
575
576 info = &info_linear->info;
577 if (!info->jited_ksyms) {
578 free(info_linear);
579 return -1;
580 }
581
582 /* number of ksyms, func_lengths, and tags should match */
583 sub_prog_cnt = info->nr_jited_ksyms;
584 if (sub_prog_cnt != info->nr_prog_tags ||
585 sub_prog_cnt != info->nr_jited_func_lens) {
586 free(info_linear);
587 return -1;
588 }
589
590 /* check BTF func info support */
591 if (info->btf_id && info->nr_func_info && info->func_info_rec_size) {
592 /* btf func info number should be same as sub_prog_cnt */
593 if (sub_prog_cnt != info->nr_func_info) {
594 pr_debug("%s: mismatch in BPF sub program count and BTF function info count, aborting\n", __func__);
595 free(info_linear);
596 return -1;
597 }
598 btf = btf__load_from_kernel_by_id(info->btf_id);
599 if (libbpf_get_error(btf)) {
600 pr_debug("%s: failed to get BTF of id %u, aborting\n", __func__, info->btf_id);
601 err = -1;
602 goto out;
603 }
604 perf_env__fetch_btf(env, info->btf_id, btf);
605 }
606
607 /* Synthesize PERF_RECORD_KSYMBOL */
608 for (i = 0; i < sub_prog_cnt; i++) {
609 __u32 *prog_lens = (__u32 *)(uintptr_t)(info->jited_func_lens);
610 __u64 *prog_addrs = (__u64 *)(uintptr_t)(info->jited_ksyms);
611 int name_len;
612
613 *ksymbol_event = (struct perf_record_ksymbol) {
614 .header = {
615 .type = PERF_RECORD_KSYMBOL,
616 .size = offsetof(struct perf_record_ksymbol, name),
617 },
618 .addr = prog_addrs[i],
619 .len = prog_lens[i],
620 .ksym_type = PERF_RECORD_KSYMBOL_TYPE_BPF,
621 .flags = 0,
622 };
623
624 name_len = synthesize_bpf_prog_name(ksymbol_event->name,
625 KSYM_NAME_LEN, info, btf, i);
626 ksymbol_event->header.size += PERF_ALIGN(name_len + 1,
627 sizeof(u64));
628
629 memset((void *)event + event->header.size, 0, machine->id_hdr_size);
630 event->header.size += machine->id_hdr_size;
631 err = perf_tool__process_synth_event(tool, event,
632 machine, process);
633 }
634
635 if (!opts->no_bpf_event) {
636 /* Synthesize PERF_RECORD_BPF_EVENT */
637 *bpf_event = (struct perf_record_bpf_event) {
638 .header = {
639 .type = PERF_RECORD_BPF_EVENT,
640 .size = sizeof(struct perf_record_bpf_event),
641 },
642 .type = PERF_BPF_EVENT_PROG_LOAD,
643 .flags = 0,
644 .id = info->id,
645 };
646 memcpy(bpf_event->tag, info->tag, BPF_TAG_SIZE);
647 memset((void *)event + event->header.size, 0, machine->id_hdr_size);
648 event->header.size += machine->id_hdr_size;
649
650 /* save bpf_prog_info to env */
651 info_node = malloc(sizeof(struct bpf_prog_info_node));
652 if (!info_node) {
653 err = -1;
654 goto out;
655 }
656
657 info_node->info_linear = info_linear;
658 info_node->metadata = NULL;
659 if (!perf_env__insert_bpf_prog_info(env, info_node)) {
660 free(info_linear);
661 free(info_node);
662 }
663 info_linear = NULL;
664
665 /*
666 * process after saving bpf_prog_info to env, so that
667 * required information is ready for look up
668 */
669 err = perf_tool__process_synth_event(tool, event,
670 machine, process);
671
672 /* Synthesize PERF_RECORD_BPF_METADATA */
673 metadata = bpf_metadata_create(info);
674 if (metadata != NULL) {
675 err = synthesize_perf_record_bpf_metadata(metadata,
676 tool, process,
677 machine);
678 bpf_metadata_free(metadata);
679 }
680 }
681
682 out:
683 free(info_linear);
684 btf__free(btf);
685 return err ? -1 : 0;
686 }
687
688 struct kallsyms_parse {
689 union perf_event *event;
690 perf_event__handler_t process;
691 struct machine *machine;
692 const struct perf_tool *tool;
693 };
694
695 static int
process_bpf_image(char * name,u64 addr,struct kallsyms_parse * data)696 process_bpf_image(char *name, u64 addr, struct kallsyms_parse *data)
697 {
698 struct machine *machine = data->machine;
699 union perf_event *event = data->event;
700 struct perf_record_ksymbol *ksymbol;
701 int len;
702
703 ksymbol = &event->ksymbol;
704
705 *ksymbol = (struct perf_record_ksymbol) {
706 .header = {
707 .type = PERF_RECORD_KSYMBOL,
708 .size = offsetof(struct perf_record_ksymbol, name),
709 },
710 .addr = addr,
711 .len = page_size,
712 .ksym_type = PERF_RECORD_KSYMBOL_TYPE_BPF,
713 .flags = 0,
714 };
715
716 len = scnprintf(ksymbol->name, KSYM_NAME_LEN, "%s", name);
717 ksymbol->header.size += PERF_ALIGN(len + 1, sizeof(u64));
718 memset((void *) event + event->header.size, 0, machine->id_hdr_size);
719 event->header.size += machine->id_hdr_size;
720
721 return perf_tool__process_synth_event(data->tool, event, machine,
722 data->process);
723 }
724
725 static int
kallsyms_process_symbol(void * data,const char * _name,char type __maybe_unused,u64 start)726 kallsyms_process_symbol(void *data, const char *_name,
727 char type __maybe_unused, u64 start)
728 {
729 char disp[KSYM_NAME_LEN];
730 char *module, *name;
731 unsigned long id;
732 int err = 0;
733
734 module = strchr(_name, '\t');
735 if (!module)
736 return 0;
737
738 /* We are going after [bpf] module ... */
739 if (strcmp(module + 1, "[bpf]"))
740 return 0;
741
742 name = memdup(_name, (module - _name) + 1);
743 if (!name)
744 return -ENOMEM;
745
746 name[module - _name] = 0;
747
748 /* .. and only for trampolines and dispatchers */
749 if ((sscanf(name, "bpf_trampoline_%lu", &id) == 1) ||
750 (sscanf(name, "bpf_dispatcher_%s", disp) == 1))
751 err = process_bpf_image(name, start, data);
752
753 free(name);
754 return err;
755 }
756
perf_event__synthesize_bpf_events(struct perf_session * session,perf_event__handler_t process,struct machine * machine,struct record_opts * opts)757 int perf_event__synthesize_bpf_events(struct perf_session *session,
758 perf_event__handler_t process,
759 struct machine *machine,
760 struct record_opts *opts)
761 {
762 const char *kallsyms_filename = "/proc/kallsyms";
763 struct kallsyms_parse arg;
764 union perf_event *event;
765 __u32 id = 0;
766 int err;
767 int fd;
768
769 if (opts->no_bpf_event)
770 return 0;
771
772 event = malloc(sizeof(event->bpf) + KSYM_NAME_LEN + machine->id_hdr_size);
773 if (!event)
774 return -1;
775
776 /* Synthesize all the bpf programs in system. */
777 while (true) {
778 err = bpf_prog_get_next_id(id, &id);
779 if (err) {
780 if (errno == ENOENT) {
781 err = 0;
782 break;
783 }
784 pr_debug("%s: can't get next program: %s%s\n",
785 __func__, strerror(errno),
786 errno == EINVAL ? " -- kernel too old?" : "");
787 /* don't report error on old kernel or EPERM */
788 err = (errno == EINVAL || errno == EPERM) ? 0 : -1;
789 break;
790 }
791 fd = bpf_prog_get_fd_by_id(id);
792 if (fd < 0) {
793 pr_debug("%s: failed to get fd for prog_id %u\n",
794 __func__, id);
795 continue;
796 }
797
798 err = perf_event__synthesize_one_bpf_prog(session, process,
799 machine, fd,
800 event, opts);
801 close(fd);
802 if (err) {
803 /* do not return error for old kernel */
804 if (err == -2)
805 err = 0;
806 break;
807 }
808 }
809
810 /* Synthesize all the bpf images - trampolines/dispatchers. */
811 if (symbol_conf.kallsyms_name != NULL)
812 kallsyms_filename = symbol_conf.kallsyms_name;
813
814 arg = (struct kallsyms_parse) {
815 .event = event,
816 .process = process,
817 .machine = machine,
818 .tool = session->tool,
819 };
820
821 if (kallsyms__parse(kallsyms_filename, &arg, kallsyms_process_symbol)) {
822 pr_err("%s: failed to synthesize bpf images: %s\n",
823 __func__, strerror(errno));
824 }
825
826 free(event);
827 return err;
828 }
829
perf_env__add_bpf_info(struct perf_env * env,u32 id)830 static void perf_env__add_bpf_info(struct perf_env *env, u32 id)
831 {
832 struct bpf_prog_info_node *info_node;
833 struct perf_bpil *info_linear;
834 struct btf *btf = NULL;
835 u64 arrays;
836 u32 btf_id;
837 int fd;
838
839 fd = bpf_prog_get_fd_by_id(id);
840 if (fd < 0)
841 return;
842
843 arrays = 1UL << PERF_BPIL_JITED_KSYMS;
844 arrays |= 1UL << PERF_BPIL_JITED_FUNC_LENS;
845 arrays |= 1UL << PERF_BPIL_FUNC_INFO;
846 arrays |= 1UL << PERF_BPIL_PROG_TAGS;
847 arrays |= 1UL << PERF_BPIL_JITED_INSNS;
848 arrays |= 1UL << PERF_BPIL_LINE_INFO;
849 arrays |= 1UL << PERF_BPIL_JITED_LINE_INFO;
850 arrays |= 1UL << PERF_BPIL_MAP_IDS;
851
852 info_linear = get_bpf_prog_info_linear(fd, arrays);
853 if (IS_ERR_OR_NULL(info_linear)) {
854 pr_debug("%s: failed to get BPF program info. aborting\n", __func__);
855 goto out;
856 }
857
858 btf_id = info_linear->info.btf_id;
859
860 info_node = malloc(sizeof(struct bpf_prog_info_node));
861 if (info_node) {
862 info_node->info_linear = info_linear;
863 info_node->metadata = bpf_metadata_create(&info_linear->info);
864 if (!perf_env__insert_bpf_prog_info(env, info_node)) {
865 free(info_linear);
866 free(info_node);
867 }
868 } else
869 free(info_linear);
870
871 if (btf_id == 0)
872 goto out;
873
874 btf = btf__load_from_kernel_by_id(btf_id);
875 if (libbpf_get_error(btf)) {
876 pr_debug("%s: failed to get BTF of id %u, aborting\n",
877 __func__, btf_id);
878 goto out;
879 }
880 perf_env__fetch_btf(env, btf_id, btf);
881
882 out:
883 btf__free(btf);
884 close(fd);
885 }
886
bpf_event__sb_cb(union perf_event * event,void * data)887 static int bpf_event__sb_cb(union perf_event *event, void *data)
888 {
889 struct perf_env *env = data;
890
891 if (event->header.type != PERF_RECORD_BPF_EVENT)
892 return -1;
893
894 switch (event->bpf.type) {
895 case PERF_BPF_EVENT_PROG_LOAD:
896 perf_env__add_bpf_info(env, event->bpf.id);
897
898 case PERF_BPF_EVENT_PROG_UNLOAD:
899 /*
900 * Do not free bpf_prog_info and btf of the program here,
901 * as annotation still need them. They will be freed at
902 * the end of the session.
903 */
904 break;
905 default:
906 pr_debug("unexpected bpf event type of %d\n", event->bpf.type);
907 break;
908 }
909
910 return 0;
911 }
912
evlist__add_bpf_sb_event(struct evlist * evlist,struct perf_env * env)913 int evlist__add_bpf_sb_event(struct evlist *evlist, struct perf_env *env)
914 {
915 struct perf_event_attr attr = {
916 .type = PERF_TYPE_SOFTWARE,
917 .config = PERF_COUNT_SW_DUMMY,
918 .sample_id_all = 1,
919 .watermark = 1,
920 .bpf_event = 1,
921 .size = sizeof(attr), /* to capture ABI version */
922 };
923
924 /*
925 * Older gcc versions don't support designated initializers, like above,
926 * for unnamed union members, such as the following:
927 */
928 attr.wakeup_watermark = 1;
929
930 return evlist__add_sb_event(evlist, &attr, bpf_event__sb_cb, env);
931 }
932
__bpf_event__print_bpf_prog_info(struct bpf_prog_info * info,struct perf_env * env,FILE * fp)933 void __bpf_event__print_bpf_prog_info(struct bpf_prog_info *info,
934 struct perf_env *env,
935 FILE *fp)
936 {
937 __u32 *prog_lens = (__u32 *)(uintptr_t)(info->jited_func_lens);
938 __u64 *prog_addrs = (__u64 *)(uintptr_t)(info->jited_ksyms);
939 char name[KSYM_NAME_LEN];
940 struct btf *btf = NULL;
941 u32 sub_prog_cnt, i;
942
943 sub_prog_cnt = info->nr_jited_ksyms;
944 if (sub_prog_cnt != info->nr_prog_tags ||
945 sub_prog_cnt != info->nr_jited_func_lens)
946 return;
947
948 if (info->btf_id) {
949 struct btf_node *node;
950
951 node = __perf_env__find_btf(env, info->btf_id);
952 if (node)
953 btf = btf__new((__u8 *)(node->data),
954 node->data_size);
955 }
956
957 if (sub_prog_cnt == 1) {
958 synthesize_bpf_prog_name(name, KSYM_NAME_LEN, info, btf, 0);
959 fprintf(fp, "# bpf_prog_info %u: %s addr 0x%llx size %u\n",
960 info->id, name, prog_addrs[0], prog_lens[0]);
961 goto out;
962 }
963
964 fprintf(fp, "# bpf_prog_info %u:\n", info->id);
965 for (i = 0; i < sub_prog_cnt; i++) {
966 synthesize_bpf_prog_name(name, KSYM_NAME_LEN, info, btf, i);
967
968 fprintf(fp, "# \tsub_prog %u: %s addr 0x%llx size %u\n",
969 i, name, prog_addrs[i], prog_lens[i]);
970 }
971 out:
972 btf__free(btf);
973 }
974