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