1 // SPDX-License-Identifier: GPL-2.0
6 #include <bpf/libbpf.h>
9 #include <linux/string.h>
10 #include <internal/lib.h>
11 #include <symbol/kallsyms.h>
12 #include "bpf-event.h"
22 #include "util/synthetic-events.h"
24 #define ptr_to_u64(ptr) ((__u64)(unsigned long)(ptr))
26 static int snprintf_hex(char *buf, size_t size, unsigned char *data, size_t len)
31 for (i = 0; i < len; i++)
32 ret += snprintf(buf + ret, size - ret, "%02x", data[i]);
36 static int machine__process_bpf_event_load(struct machine *machine,
37 union perf_event *event,
38 struct perf_sample *sample __maybe_unused)
40 struct bpf_prog_info_linear *info_linear;
41 struct bpf_prog_info_node *info_node;
42 struct perf_env *env = machine->env;
43 int id = event->bpf.id;
46 /* perf-record, no need to handle bpf-event */
50 info_node = perf_env__find_bpf_prog_info(env, id);
53 info_linear = info_node->info_linear;
55 for (i = 0; i < info_linear->info.nr_jited_ksyms; i++) {
56 u64 *addrs = (u64 *)(uintptr_t)(info_linear->info.jited_ksyms);
58 struct map *map = maps__find(&machine->kmaps, addr);
61 map->dso->binary_type = DSO_BINARY_TYPE__BPF_PROG_INFO;
62 map->dso->bpf_prog.id = id;
63 map->dso->bpf_prog.sub_id = i;
64 map->dso->bpf_prog.env = env;
70 int machine__process_bpf(struct machine *machine, union perf_event *event,
71 struct perf_sample *sample)
74 perf_event__fprintf_bpf(event, stdout);
76 switch (event->bpf.type) {
77 case PERF_BPF_EVENT_PROG_LOAD:
78 return machine__process_bpf_event_load(machine, event, sample);
80 case PERF_BPF_EVENT_PROG_UNLOAD:
82 * Do not free bpf_prog_info and btf of the program here,
83 * as annotation still need them. They will be freed at
84 * the end of the session.
88 pr_debug("unexpected bpf event type of %d\n", event->bpf.type);
94 static int perf_env__fetch_btf(struct perf_env *env,
98 struct btf_node *node;
102 data = btf__get_raw_data(btf, &data_size);
104 node = malloc(data_size + sizeof(struct btf_node));
109 node->data_size = data_size;
110 memcpy(node->data, data, data_size);
112 perf_env__insert_btf(env, node);
116 static int synthesize_bpf_prog_name(char *buf, int size,
117 struct bpf_prog_info *info,
121 u8 (*prog_tags)[BPF_TAG_SIZE] = (void *)(uintptr_t)(info->prog_tags);
122 void *func_infos = (void *)(uintptr_t)(info->func_info);
123 u32 sub_prog_cnt = info->nr_jited_ksyms;
124 const struct bpf_func_info *finfo;
125 const char *short_name = NULL;
126 const struct btf_type *t;
129 name_len = snprintf(buf, size, "bpf_prog_");
130 name_len += snprintf_hex(buf + name_len, size - name_len,
131 prog_tags[sub_id], BPF_TAG_SIZE);
133 finfo = func_infos + sub_id * info->func_info_rec_size;
134 t = btf__type_by_id(btf, finfo->type_id);
135 short_name = btf__name_by_offset(btf, t->name_off);
136 } else if (sub_id == 0 && sub_prog_cnt == 1) {
139 short_name = info->name;
143 name_len += snprintf(buf + name_len, size - name_len,
149 * Synthesize PERF_RECORD_KSYMBOL and PERF_RECORD_BPF_EVENT for one bpf
150 * program. One PERF_RECORD_BPF_EVENT is generated for the program. And
151 * one PERF_RECORD_KSYMBOL is generated for each sub program.
156 * -2 for lack of kernel support.
158 static int perf_event__synthesize_one_bpf_prog(struct perf_session *session,
159 perf_event__handler_t process,
160 struct machine *machine,
162 union perf_event *event,
163 struct record_opts *opts)
165 struct perf_record_ksymbol *ksymbol_event = &event->ksymbol;
166 struct perf_record_bpf_event *bpf_event = &event->bpf;
167 struct bpf_prog_info_linear *info_linear;
168 struct perf_tool *tool = session->tool;
169 struct bpf_prog_info_node *info_node;
170 struct bpf_prog_info *info;
171 struct btf *btf = NULL;
172 struct perf_env *env;
178 * for perf-record and perf-report use header.env;
179 * otherwise, use global perf_env.
181 env = session->data ? &session->header.env : &perf_env;
183 arrays = 1UL << BPF_PROG_INFO_JITED_KSYMS;
184 arrays |= 1UL << BPF_PROG_INFO_JITED_FUNC_LENS;
185 arrays |= 1UL << BPF_PROG_INFO_FUNC_INFO;
186 arrays |= 1UL << BPF_PROG_INFO_PROG_TAGS;
187 arrays |= 1UL << BPF_PROG_INFO_JITED_INSNS;
188 arrays |= 1UL << BPF_PROG_INFO_LINE_INFO;
189 arrays |= 1UL << BPF_PROG_INFO_JITED_LINE_INFO;
191 info_linear = bpf_program__get_prog_info_linear(fd, arrays);
192 if (IS_ERR_OR_NULL(info_linear)) {
194 pr_debug("%s: failed to get BPF program info. aborting\n", __func__);
198 if (info_linear->info_len < offsetof(struct bpf_prog_info, prog_tags)) {
199 pr_debug("%s: the kernel is too old, aborting\n", __func__);
203 info = &info_linear->info;
205 /* number of ksyms, func_lengths, and tags should match */
206 sub_prog_cnt = info->nr_jited_ksyms;
207 if (sub_prog_cnt != info->nr_prog_tags ||
208 sub_prog_cnt != info->nr_jited_func_lens)
211 /* check BTF func info support */
212 if (info->btf_id && info->nr_func_info && info->func_info_rec_size) {
213 /* btf func info number should be same as sub_prog_cnt */
214 if (sub_prog_cnt != info->nr_func_info) {
215 pr_debug("%s: mismatch in BPF sub program count and BTF function info count, aborting\n", __func__);
219 if (btf__get_from_id(info->btf_id, &btf)) {
220 pr_debug("%s: failed to get BTF of id %u, aborting\n", __func__, info->btf_id);
225 perf_env__fetch_btf(env, info->btf_id, btf);
228 /* Synthesize PERF_RECORD_KSYMBOL */
229 for (i = 0; i < sub_prog_cnt; i++) {
230 __u32 *prog_lens = (__u32 *)(uintptr_t)(info->jited_func_lens);
231 __u64 *prog_addrs = (__u64 *)(uintptr_t)(info->jited_ksyms);
234 *ksymbol_event = (struct perf_record_ksymbol) {
236 .type = PERF_RECORD_KSYMBOL,
237 .size = offsetof(struct perf_record_ksymbol, name),
239 .addr = prog_addrs[i],
241 .ksym_type = PERF_RECORD_KSYMBOL_TYPE_BPF,
245 name_len = synthesize_bpf_prog_name(ksymbol_event->name,
246 KSYM_NAME_LEN, info, btf, i);
247 ksymbol_event->header.size += PERF_ALIGN(name_len + 1,
250 memset((void *)event + event->header.size, 0, machine->id_hdr_size);
251 event->header.size += machine->id_hdr_size;
252 err = perf_tool__process_synth_event(tool, event,
256 if (!opts->no_bpf_event) {
257 /* Synthesize PERF_RECORD_BPF_EVENT */
258 *bpf_event = (struct perf_record_bpf_event) {
260 .type = PERF_RECORD_BPF_EVENT,
261 .size = sizeof(struct perf_record_bpf_event),
263 .type = PERF_BPF_EVENT_PROG_LOAD,
267 memcpy(bpf_event->tag, info->tag, BPF_TAG_SIZE);
268 memset((void *)event + event->header.size, 0, machine->id_hdr_size);
269 event->header.size += machine->id_hdr_size;
271 /* save bpf_prog_info to env */
272 info_node = malloc(sizeof(struct bpf_prog_info_node));
278 info_node->info_linear = info_linear;
279 perf_env__insert_bpf_prog_info(env, info_node);
283 * process after saving bpf_prog_info to env, so that
284 * required information is ready for look up
286 err = perf_tool__process_synth_event(tool, event,
296 struct kallsyms_parse {
297 union perf_event *event;
298 perf_event__handler_t process;
299 struct machine *machine;
300 struct perf_tool *tool;
304 process_bpf_image(char *name, u64 addr, struct kallsyms_parse *data)
306 struct machine *machine = data->machine;
307 union perf_event *event = data->event;
308 struct perf_record_ksymbol *ksymbol;
311 ksymbol = &event->ksymbol;
313 *ksymbol = (struct perf_record_ksymbol) {
315 .type = PERF_RECORD_KSYMBOL,
316 .size = offsetof(struct perf_record_ksymbol, name),
320 .ksym_type = PERF_RECORD_KSYMBOL_TYPE_BPF,
324 len = scnprintf(ksymbol->name, KSYM_NAME_LEN, "%s", name);
325 ksymbol->header.size += PERF_ALIGN(len + 1, sizeof(u64));
326 memset((void *) event + event->header.size, 0, machine->id_hdr_size);
327 event->header.size += machine->id_hdr_size;
329 return perf_tool__process_synth_event(data->tool, event, machine,
334 kallsyms_process_symbol(void *data, const char *_name,
335 char type __maybe_unused, u64 start)
337 char disp[KSYM_NAME_LEN];
342 module = strchr(_name, '\t');
346 /* We are going after [bpf] module ... */
347 if (strcmp(module + 1, "[bpf]"))
350 name = memdup(_name, (module - _name) + 1);
354 name[module - _name] = 0;
356 /* .. and only for trampolines and dispatchers */
357 if ((sscanf(name, "bpf_trampoline_%lu", &id) == 1) ||
358 (sscanf(name, "bpf_dispatcher_%s", disp) == 1))
359 err = process_bpf_image(name, start, data);
365 int perf_event__synthesize_bpf_events(struct perf_session *session,
366 perf_event__handler_t process,
367 struct machine *machine,
368 struct record_opts *opts)
370 const char *kallsyms_filename = "/proc/kallsyms";
371 struct kallsyms_parse arg;
372 union perf_event *event;
377 event = malloc(sizeof(event->bpf) + KSYM_NAME_LEN + machine->id_hdr_size);
381 /* Synthesize all the bpf programs in system. */
383 err = bpf_prog_get_next_id(id, &id);
385 if (errno == ENOENT) {
389 pr_debug("%s: can't get next program: %s%s\n",
390 __func__, strerror(errno),
391 errno == EINVAL ? " -- kernel too old?" : "");
392 /* don't report error on old kernel or EPERM */
393 err = (errno == EINVAL || errno == EPERM) ? 0 : -1;
396 fd = bpf_prog_get_fd_by_id(id);
398 pr_debug("%s: failed to get fd for prog_id %u\n",
403 err = perf_event__synthesize_one_bpf_prog(session, process,
408 /* do not return error for old kernel */
415 /* Synthesize all the bpf images - trampolines/dispatchers. */
416 if (symbol_conf.kallsyms_name != NULL)
417 kallsyms_filename = symbol_conf.kallsyms_name;
419 arg = (struct kallsyms_parse) {
423 .tool = session->tool,
426 if (kallsyms__parse(kallsyms_filename, &arg, kallsyms_process_symbol)) {
427 pr_err("%s: failed to synthesize bpf images: %s\n",
428 __func__, strerror(errno));
435 static void perf_env__add_bpf_info(struct perf_env *env, u32 id)
437 struct bpf_prog_info_linear *info_linear;
438 struct bpf_prog_info_node *info_node;
439 struct btf *btf = NULL;
444 fd = bpf_prog_get_fd_by_id(id);
448 arrays = 1UL << BPF_PROG_INFO_JITED_KSYMS;
449 arrays |= 1UL << BPF_PROG_INFO_JITED_FUNC_LENS;
450 arrays |= 1UL << BPF_PROG_INFO_FUNC_INFO;
451 arrays |= 1UL << BPF_PROG_INFO_PROG_TAGS;
452 arrays |= 1UL << BPF_PROG_INFO_JITED_INSNS;
453 arrays |= 1UL << BPF_PROG_INFO_LINE_INFO;
454 arrays |= 1UL << BPF_PROG_INFO_JITED_LINE_INFO;
456 info_linear = bpf_program__get_prog_info_linear(fd, arrays);
457 if (IS_ERR_OR_NULL(info_linear)) {
458 pr_debug("%s: failed to get BPF program info. aborting\n", __func__);
462 btf_id = info_linear->info.btf_id;
464 info_node = malloc(sizeof(struct bpf_prog_info_node));
466 info_node->info_linear = info_linear;
467 perf_env__insert_bpf_prog_info(env, info_node);
474 if (btf__get_from_id(btf_id, &btf)) {
475 pr_debug("%s: failed to get BTF of id %u, aborting\n",
479 perf_env__fetch_btf(env, btf_id, btf);
486 static int bpf_event__sb_cb(union perf_event *event, void *data)
488 struct perf_env *env = data;
490 if (event->header.type != PERF_RECORD_BPF_EVENT)
493 switch (event->bpf.type) {
494 case PERF_BPF_EVENT_PROG_LOAD:
495 perf_env__add_bpf_info(env, event->bpf.id);
497 case PERF_BPF_EVENT_PROG_UNLOAD:
499 * Do not free bpf_prog_info and btf of the program here,
500 * as annotation still need them. They will be freed at
501 * the end of the session.
505 pr_debug("unexpected bpf event type of %d\n", event->bpf.type);
512 int evlist__add_bpf_sb_event(struct evlist *evlist, struct perf_env *env)
514 struct perf_event_attr attr = {
515 .type = PERF_TYPE_SOFTWARE,
516 .config = PERF_COUNT_SW_DUMMY,
520 .size = sizeof(attr), /* to capture ABI version */
524 * Older gcc versions don't support designated initializers, like above,
525 * for unnamed union members, such as the following:
527 attr.wakeup_watermark = 1;
529 return evlist__add_sb_event(evlist, &attr, bpf_event__sb_cb, env);
532 void bpf_event__print_bpf_prog_info(struct bpf_prog_info *info,
533 struct perf_env *env,
536 __u32 *prog_lens = (__u32 *)(uintptr_t)(info->jited_func_lens);
537 __u64 *prog_addrs = (__u64 *)(uintptr_t)(info->jited_ksyms);
538 char name[KSYM_NAME_LEN];
539 struct btf *btf = NULL;
542 sub_prog_cnt = info->nr_jited_ksyms;
543 if (sub_prog_cnt != info->nr_prog_tags ||
544 sub_prog_cnt != info->nr_jited_func_lens)
548 struct btf_node *node;
550 node = perf_env__find_btf(env, info->btf_id);
552 btf = btf__new((__u8 *)(node->data),
556 if (sub_prog_cnt == 1) {
557 synthesize_bpf_prog_name(name, KSYM_NAME_LEN, info, btf, 0);
558 fprintf(fp, "# bpf_prog_info %u: %s addr 0x%llx size %u\n",
559 info->id, name, prog_addrs[0], prog_lens[0]);
563 fprintf(fp, "# bpf_prog_info %u:\n", info->id);
564 for (i = 0; i < sub_prog_cnt; i++) {
565 synthesize_bpf_prog_name(name, KSYM_NAME_LEN, info, btf, i);
567 fprintf(fp, "# \tsub_prog %u: %s addr 0x%llx size %u\n",
568 i, name, prog_addrs[i], prog_lens[i]);