1
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 "symbol.h"
12#include "machine.h"
13#include "env.h"
14#include "session.h"
15#include "map.h"
16#include "evlist.h"
17
18#define ptr_to_u64(ptr) ((__u64)(unsigned long)(ptr))
19
20static int snprintf_hex(char *buf, size_t size, unsigned char *data, size_t len)
21{
22 int ret = 0;
23 size_t i;
24
25 for (i = 0; i < len; i++)
26 ret += snprintf(buf + ret, size - ret, "%02x", data[i]);
27 return ret;
28}
29
30static int machine__process_bpf_event_load(struct machine *machine,
31 union perf_event *event,
32 struct perf_sample *sample __maybe_unused)
33{
34 struct bpf_prog_info_linear *info_linear;
35 struct bpf_prog_info_node *info_node;
36 struct perf_env *env = machine->env;
37 int id = event->bpf_event.id;
38 unsigned int i;
39
40
41 if (env == NULL)
42 return 0;
43
44 info_node = perf_env__find_bpf_prog_info(env, id);
45 if (!info_node)
46 return 0;
47 info_linear = info_node->info_linear;
48
49 for (i = 0; i < info_linear->info.nr_jited_ksyms; i++) {
50 u64 *addrs = (u64 *)(uintptr_t)(info_linear->info.jited_ksyms);
51 u64 addr = addrs[i];
52 struct map *map;
53
54 map = map_groups__find(&machine->kmaps, addr);
55
56 if (map) {
57 map->dso->binary_type = DSO_BINARY_TYPE__BPF_PROG_INFO;
58 map->dso->bpf_prog.id = id;
59 map->dso->bpf_prog.sub_id = i;
60 map->dso->bpf_prog.env = env;
61 }
62 }
63 return 0;
64}
65
66int machine__process_bpf_event(struct machine *machine __maybe_unused,
67 union perf_event *event,
68 struct perf_sample *sample __maybe_unused)
69{
70 if (dump_trace)
71 perf_event__fprintf_bpf_event(event, stdout);
72
73 switch (event->bpf_event.type) {
74 case PERF_BPF_EVENT_PROG_LOAD:
75 return machine__process_bpf_event_load(machine, event, sample);
76
77 case PERF_BPF_EVENT_PROG_UNLOAD:
78
79
80
81
82
83 break;
84 default:
85 pr_debug("unexpected bpf_event type of %d\n",
86 event->bpf_event.type);
87 break;
88 }
89 return 0;
90}
91
92static int perf_env__fetch_btf(struct perf_env *env,
93 u32 btf_id,
94 struct btf *btf)
95{
96 struct btf_node *node;
97 u32 data_size;
98 const void *data;
99
100 data = btf__get_raw_data(btf, &data_size);
101
102 node = malloc(data_size + sizeof(struct btf_node));
103 if (!node)
104 return -1;
105
106 node->id = btf_id;
107 node->data_size = data_size;
108 memcpy(node->data, data, data_size);
109
110 perf_env__insert_btf(env, node);
111 return 0;
112}
113
114static int synthesize_bpf_prog_name(char *buf, int size,
115 struct bpf_prog_info *info,
116 struct btf *btf,
117 u32 sub_id)
118{
119 u8 (*prog_tags)[BPF_TAG_SIZE] = (void *)(uintptr_t)(info->prog_tags);
120 void *func_infos = (void *)(uintptr_t)(info->func_info);
121 u32 sub_prog_cnt = info->nr_jited_ksyms;
122 const struct bpf_func_info *finfo;
123 const char *short_name = NULL;
124 const struct btf_type *t;
125 int name_len;
126
127 name_len = snprintf(buf, size, "bpf_prog_");
128 name_len += snprintf_hex(buf + name_len, size - name_len,
129 prog_tags[sub_id], BPF_TAG_SIZE);
130 if (btf) {
131 finfo = func_infos + sub_id * info->func_info_rec_size;
132 t = btf__type_by_id(btf, finfo->type_id);
133 short_name = btf__name_by_offset(btf, t->name_off);
134 } else if (sub_id == 0 && sub_prog_cnt == 1) {
135
136 if (info->name[0])
137 short_name = info->name;
138 } else
139 short_name = "F";
140 if (short_name)
141 name_len += snprintf(buf + name_len, size - name_len,
142 "_%s", short_name);
143 return name_len;
144}
145
146
147
148
149
150
151
152
153
154
155
156static int perf_event__synthesize_one_bpf_prog(struct perf_session *session,
157 perf_event__handler_t process,
158 struct machine *machine,
159 int fd,
160 union perf_event *event,
161 struct record_opts *opts)
162{
163 struct ksymbol_event *ksymbol_event = &event->ksymbol_event;
164 struct bpf_event *bpf_event = &event->bpf_event;
165 struct bpf_prog_info_linear *info_linear;
166 struct perf_tool *tool = session->tool;
167 struct bpf_prog_info_node *info_node;
168 struct bpf_prog_info *info;
169 struct btf *btf = NULL;
170 struct perf_env *env;
171 u32 sub_prog_cnt, i;
172 int err = 0;
173 u64 arrays;
174
175
176
177
178
179 env = session->data ? &session->header.env : &perf_env;
180
181 arrays = 1UL << BPF_PROG_INFO_JITED_KSYMS;
182 arrays |= 1UL << BPF_PROG_INFO_JITED_FUNC_LENS;
183 arrays |= 1UL << BPF_PROG_INFO_FUNC_INFO;
184 arrays |= 1UL << BPF_PROG_INFO_PROG_TAGS;
185 arrays |= 1UL << BPF_PROG_INFO_JITED_INSNS;
186 arrays |= 1UL << BPF_PROG_INFO_LINE_INFO;
187 arrays |= 1UL << BPF_PROG_INFO_JITED_LINE_INFO;
188
189 info_linear = bpf_program__get_prog_info_linear(fd, arrays);
190 if (IS_ERR_OR_NULL(info_linear)) {
191 info_linear = NULL;
192 pr_debug("%s: failed to get BPF program info. aborting\n", __func__);
193 return -1;
194 }
195
196 if (info_linear->info_len < offsetof(struct bpf_prog_info, prog_tags)) {
197 pr_debug("%s: the kernel is too old, aborting\n", __func__);
198 return -2;
199 }
200
201 info = &info_linear->info;
202
203
204 sub_prog_cnt = info->nr_jited_ksyms;
205 if (sub_prog_cnt != info->nr_prog_tags ||
206 sub_prog_cnt != info->nr_jited_func_lens)
207 return -1;
208
209
210 if (info->btf_id && info->nr_func_info && info->func_info_rec_size) {
211
212 if (sub_prog_cnt != info->nr_func_info) {
213 pr_debug("%s: mismatch in BPF sub program count and BTF function info count, aborting\n", __func__);
214 err = -1;
215 goto out;
216 }
217 if (btf__get_from_id(info->btf_id, &btf)) {
218 pr_debug("%s: failed to get BTF of id %u, aborting\n", __func__, info->btf_id);
219 err = -1;
220 btf = NULL;
221 goto out;
222 }
223 perf_env__fetch_btf(env, info->btf_id, btf);
224 }
225
226
227 for (i = 0; i < sub_prog_cnt; i++) {
228 __u32 *prog_lens = (__u32 *)(uintptr_t)(info->jited_func_lens);
229 __u64 *prog_addrs = (__u64 *)(uintptr_t)(info->jited_ksyms);
230 int name_len;
231
232 *ksymbol_event = (struct ksymbol_event){
233 .header = {
234 .type = PERF_RECORD_KSYMBOL,
235 .size = offsetof(struct ksymbol_event, name),
236 },
237 .addr = prog_addrs[i],
238 .len = prog_lens[i],
239 .ksym_type = PERF_RECORD_KSYMBOL_TYPE_BPF,
240 .flags = 0,
241 };
242
243 name_len = synthesize_bpf_prog_name(ksymbol_event->name,
244 KSYM_NAME_LEN, info, btf, i);
245 ksymbol_event->header.size += PERF_ALIGN(name_len + 1,
246 sizeof(u64));
247
248 memset((void *)event + event->header.size, 0, machine->id_hdr_size);
249 event->header.size += machine->id_hdr_size;
250 err = perf_tool__process_synth_event(tool, event,
251 machine, process);
252 }
253
254 if (!opts->no_bpf_event) {
255
256 *bpf_event = (struct bpf_event){
257 .header = {
258 .type = PERF_RECORD_BPF_EVENT,
259 .size = sizeof(struct bpf_event),
260 },
261 .type = PERF_BPF_EVENT_PROG_LOAD,
262 .flags = 0,
263 .id = info->id,
264 };
265 memcpy(bpf_event->tag, info->tag, BPF_TAG_SIZE);
266 memset((void *)event + event->header.size, 0, machine->id_hdr_size);
267 event->header.size += machine->id_hdr_size;
268
269
270 info_node = malloc(sizeof(struct bpf_prog_info_node));
271 if (!info_node) {
272 err = -1;
273 goto out;
274 }
275
276 info_node->info_linear = info_linear;
277 perf_env__insert_bpf_prog_info(env, info_node);
278 info_linear = NULL;
279
280
281
282
283
284 err = perf_tool__process_synth_event(tool, event,
285 machine, process);
286 }
287
288out:
289 free(info_linear);
290 free(btf);
291 return err ? -1 : 0;
292}
293
294int perf_event__synthesize_bpf_events(struct perf_session *session,
295 perf_event__handler_t process,
296 struct machine *machine,
297 struct record_opts *opts)
298{
299 union perf_event *event;
300 __u32 id = 0;
301 int err;
302 int fd;
303
304 event = malloc(sizeof(event->bpf_event) + KSYM_NAME_LEN + machine->id_hdr_size);
305 if (!event)
306 return -1;
307 while (true) {
308 err = bpf_prog_get_next_id(id, &id);
309 if (err) {
310 if (errno == ENOENT) {
311 err = 0;
312 break;
313 }
314 pr_debug("%s: can't get next program: %s%s\n",
315 __func__, strerror(errno),
316 errno == EINVAL ? " -- kernel too old?" : "");
317
318 err = (errno == EINVAL || errno == EPERM) ? 0 : -1;
319 break;
320 }
321 fd = bpf_prog_get_fd_by_id(id);
322 if (fd < 0) {
323 pr_debug("%s: failed to get fd for prog_id %u\n",
324 __func__, id);
325 continue;
326 }
327
328 err = perf_event__synthesize_one_bpf_prog(session, process,
329 machine, fd,
330 event, opts);
331 close(fd);
332 if (err) {
333
334 if (err == -2)
335 err = 0;
336 break;
337 }
338 }
339 free(event);
340 return err;
341}
342
343static void perf_env__add_bpf_info(struct perf_env *env, u32 id)
344{
345 struct bpf_prog_info_linear *info_linear;
346 struct bpf_prog_info_node *info_node;
347 struct btf *btf = NULL;
348 u64 arrays;
349 u32 btf_id;
350 int fd;
351
352 fd = bpf_prog_get_fd_by_id(id);
353 if (fd < 0)
354 return;
355
356 arrays = 1UL << BPF_PROG_INFO_JITED_KSYMS;
357 arrays |= 1UL << BPF_PROG_INFO_JITED_FUNC_LENS;
358 arrays |= 1UL << BPF_PROG_INFO_FUNC_INFO;
359 arrays |= 1UL << BPF_PROG_INFO_PROG_TAGS;
360 arrays |= 1UL << BPF_PROG_INFO_JITED_INSNS;
361 arrays |= 1UL << BPF_PROG_INFO_LINE_INFO;
362 arrays |= 1UL << BPF_PROG_INFO_JITED_LINE_INFO;
363
364 info_linear = bpf_program__get_prog_info_linear(fd, arrays);
365 if (IS_ERR_OR_NULL(info_linear)) {
366 pr_debug("%s: failed to get BPF program info. aborting\n", __func__);
367 goto out;
368 }
369
370 btf_id = info_linear->info.btf_id;
371
372 info_node = malloc(sizeof(struct bpf_prog_info_node));
373 if (info_node) {
374 info_node->info_linear = info_linear;
375 perf_env__insert_bpf_prog_info(env, info_node);
376 } else
377 free(info_linear);
378
379 if (btf_id == 0)
380 goto out;
381
382 if (btf__get_from_id(btf_id, &btf)) {
383 pr_debug("%s: failed to get BTF of id %u, aborting\n",
384 __func__, btf_id);
385 goto out;
386 }
387 perf_env__fetch_btf(env, btf_id, btf);
388
389out:
390 free(btf);
391 close(fd);
392}
393
394static int bpf_event__sb_cb(union perf_event *event, void *data)
395{
396 struct perf_env *env = data;
397
398 if (event->header.type != PERF_RECORD_BPF_EVENT)
399 return -1;
400
401 switch (event->bpf_event.type) {
402 case PERF_BPF_EVENT_PROG_LOAD:
403 perf_env__add_bpf_info(env, event->bpf_event.id);
404
405 case PERF_BPF_EVENT_PROG_UNLOAD:
406
407
408
409
410
411 break;
412 default:
413 pr_debug("unexpected bpf_event type of %d\n",
414 event->bpf_event.type);
415 break;
416 }
417
418 return 0;
419}
420
421int bpf_event__add_sb_event(struct perf_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),
431 };
432
433
434
435
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}
481
