1 | // SPDX-License-Identifier: GPL-2.0-or-later |
2 | /* |
3 | * probe-file.c : operate ftrace k/uprobe events files |
4 | * |
5 | * Written by Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> |
6 | */ |
7 | #include <errno.h> |
8 | #include <fcntl.h> |
9 | #include <sys/stat.h> |
10 | #include <sys/types.h> |
11 | #include <sys/uio.h> |
12 | #include <unistd.h> |
13 | #include <linux/zalloc.h> |
14 | #include "namespaces.h" |
15 | #include "event.h" |
16 | #include "strlist.h" |
17 | #include "strfilter.h" |
18 | #include "debug.h" |
19 | #include "build-id.h" |
20 | #include "dso.h" |
21 | #include "color.h" |
22 | #include "symbol.h" |
23 | #include "strbuf.h" |
24 | #include <api/fs/tracing_path.h> |
25 | #include <api/fs/fs.h> |
26 | #include "probe-event.h" |
27 | #include "probe-file.h" |
28 | #include "session.h" |
29 | #include "perf_regs.h" |
30 | #include "string2.h" |
31 | |
32 | /* 4096 - 2 ('\n' + '\0') */ |
33 | #define MAX_CMDLEN 4094 |
34 | |
35 | static bool print_common_warning(int err, bool readwrite) |
36 | { |
37 | if (err == -EACCES) |
38 | pr_warning("No permission to %s tracefs.\nPlease %s\n" , |
39 | readwrite ? "write" : "read" , |
40 | readwrite ? "run this command again with sudo." : |
41 | "try 'sudo mount -o remount,mode=755 /sys/kernel/tracing/'" ); |
42 | else |
43 | return false; |
44 | |
45 | return true; |
46 | } |
47 | |
48 | static bool print_configure_probe_event(int kerr, int uerr) |
49 | { |
50 | const char *config, *file; |
51 | |
52 | if (kerr == -ENOENT && uerr == -ENOENT) { |
53 | file = "{k,u}probe_events" ; |
54 | config = "CONFIG_KPROBE_EVENTS=y and CONFIG_UPROBE_EVENTS=y" ; |
55 | } else if (kerr == -ENOENT) { |
56 | file = "kprobe_events" ; |
57 | config = "CONFIG_KPROBE_EVENTS=y" ; |
58 | } else if (uerr == -ENOENT) { |
59 | file = "uprobe_events" ; |
60 | config = "CONFIG_UPROBE_EVENTS=y" ; |
61 | } else |
62 | return false; |
63 | |
64 | if (!debugfs__configured() && !tracefs__configured()) |
65 | pr_warning("Debugfs or tracefs is not mounted\n" |
66 | "Please try 'sudo mount -t tracefs nodev /sys/kernel/tracing/'\n" ); |
67 | else |
68 | pr_warning("%s/%s does not exist.\nPlease rebuild kernel with %s.\n" , |
69 | tracing_path_mount(), file, config); |
70 | |
71 | return true; |
72 | } |
73 | |
74 | static void print_open_warning(int err, bool uprobe, bool readwrite) |
75 | { |
76 | char sbuf[STRERR_BUFSIZE]; |
77 | |
78 | if (print_common_warning(err, readwrite)) |
79 | return; |
80 | |
81 | if (print_configure_probe_event(kerr: uprobe ? 0 : err, uerr: uprobe ? err : 0)) |
82 | return; |
83 | |
84 | pr_warning("Failed to open %s/%cprobe_events: %s\n" , |
85 | tracing_path_mount(), uprobe ? 'u' : 'k', |
86 | str_error_r(-err, sbuf, sizeof(sbuf))); |
87 | } |
88 | |
89 | static void print_both_open_warning(int kerr, int uerr, bool readwrite) |
90 | { |
91 | char sbuf[STRERR_BUFSIZE]; |
92 | |
93 | if (kerr == uerr && print_common_warning(err: kerr, readwrite)) |
94 | return; |
95 | |
96 | if (print_configure_probe_event(kerr, uerr)) |
97 | return; |
98 | |
99 | if (kerr < 0) |
100 | pr_warning("Failed to open %s/kprobe_events: %s.\n" , |
101 | tracing_path_mount(), |
102 | str_error_r(-kerr, sbuf, sizeof(sbuf))); |
103 | if (uerr < 0) |
104 | pr_warning("Failed to open %s/uprobe_events: %s.\n" , |
105 | tracing_path_mount(), |
106 | str_error_r(-uerr, sbuf, sizeof(sbuf))); |
107 | } |
108 | |
109 | int open_trace_file(const char *trace_file, bool readwrite) |
110 | { |
111 | char buf[PATH_MAX]; |
112 | int ret; |
113 | |
114 | ret = e_snprintf(str: buf, PATH_MAX, format: "%s/%s" , tracing_path_mount(), trace_file); |
115 | if (ret >= 0) { |
116 | pr_debug("Opening %s write=%d\n" , buf, readwrite); |
117 | if (readwrite && !probe_event_dry_run) |
118 | ret = open(buf, O_RDWR | O_APPEND, 0); |
119 | else |
120 | ret = open(buf, O_RDONLY, 0); |
121 | |
122 | if (ret < 0) |
123 | ret = -errno; |
124 | } |
125 | return ret; |
126 | } |
127 | |
128 | static int open_kprobe_events(bool readwrite) |
129 | { |
130 | return open_trace_file(trace_file: "kprobe_events" , readwrite); |
131 | } |
132 | |
133 | static int open_uprobe_events(bool readwrite) |
134 | { |
135 | return open_trace_file(trace_file: "uprobe_events" , readwrite); |
136 | } |
137 | |
138 | int probe_file__open(int flag) |
139 | { |
140 | int fd; |
141 | |
142 | if (flag & PF_FL_UPROBE) |
143 | fd = open_uprobe_events(readwrite: flag & PF_FL_RW); |
144 | else |
145 | fd = open_kprobe_events(readwrite: flag & PF_FL_RW); |
146 | if (fd < 0) |
147 | print_open_warning(err: fd, uprobe: flag & PF_FL_UPROBE, readwrite: flag & PF_FL_RW); |
148 | |
149 | return fd; |
150 | } |
151 | |
152 | int probe_file__open_both(int *kfd, int *ufd, int flag) |
153 | { |
154 | if (!kfd || !ufd) |
155 | return -EINVAL; |
156 | |
157 | *kfd = open_kprobe_events(readwrite: flag & PF_FL_RW); |
158 | *ufd = open_uprobe_events(readwrite: flag & PF_FL_RW); |
159 | if (*kfd < 0 && *ufd < 0) { |
160 | print_both_open_warning(kerr: *kfd, uerr: *ufd, readwrite: flag & PF_FL_RW); |
161 | return *kfd; |
162 | } |
163 | |
164 | return 0; |
165 | } |
166 | |
167 | /* Get raw string list of current kprobe_events or uprobe_events */ |
168 | struct strlist *probe_file__get_rawlist(int fd) |
169 | { |
170 | int ret, idx, fddup; |
171 | FILE *fp; |
172 | char buf[MAX_CMDLEN]; |
173 | char *p; |
174 | struct strlist *sl; |
175 | |
176 | if (fd < 0) |
177 | return NULL; |
178 | |
179 | sl = strlist__new(NULL, NULL); |
180 | if (sl == NULL) |
181 | return NULL; |
182 | |
183 | fddup = dup(fd); |
184 | if (fddup < 0) |
185 | goto out_free_sl; |
186 | |
187 | fp = fdopen(fddup, "r" ); |
188 | if (!fp) |
189 | goto out_close_fddup; |
190 | |
191 | while (!feof(fp)) { |
192 | p = fgets(buf, MAX_CMDLEN, fp); |
193 | if (!p) |
194 | break; |
195 | |
196 | idx = strlen(p) - 1; |
197 | if (p[idx] == '\n') |
198 | p[idx] = '\0'; |
199 | ret = strlist__add(slist: sl, str: buf); |
200 | if (ret < 0) { |
201 | pr_debug("strlist__add failed (%d)\n" , ret); |
202 | goto out_close_fp; |
203 | } |
204 | } |
205 | fclose(fp); |
206 | |
207 | return sl; |
208 | |
209 | out_close_fp: |
210 | fclose(fp); |
211 | goto out_free_sl; |
212 | out_close_fddup: |
213 | close(fddup); |
214 | out_free_sl: |
215 | strlist__delete(slist: sl); |
216 | return NULL; |
217 | } |
218 | |
219 | static struct strlist *__probe_file__get_namelist(int fd, bool include_group) |
220 | { |
221 | char buf[128]; |
222 | struct strlist *sl, *rawlist; |
223 | struct str_node *ent; |
224 | struct probe_trace_event tev; |
225 | int ret = 0; |
226 | |
227 | memset(&tev, 0, sizeof(tev)); |
228 | rawlist = probe_file__get_rawlist(fd); |
229 | if (!rawlist) |
230 | return NULL; |
231 | sl = strlist__new(NULL, NULL); |
232 | strlist__for_each_entry(ent, rawlist) { |
233 | ret = parse_probe_trace_command(cmd: ent->s, tev: &tev); |
234 | if (ret < 0) |
235 | break; |
236 | if (include_group) { |
237 | ret = e_snprintf(str: buf, size: 128, format: "%s:%s" , tev.group, |
238 | tev.event); |
239 | if (ret >= 0) |
240 | ret = strlist__add(slist: sl, str: buf); |
241 | } else |
242 | ret = strlist__add(slist: sl, str: tev.event); |
243 | clear_probe_trace_event(tev: &tev); |
244 | /* Skip if there is same name multi-probe event in the list */ |
245 | if (ret == -EEXIST) |
246 | ret = 0; |
247 | if (ret < 0) |
248 | break; |
249 | } |
250 | strlist__delete(slist: rawlist); |
251 | |
252 | if (ret < 0) { |
253 | strlist__delete(slist: sl); |
254 | return NULL; |
255 | } |
256 | return sl; |
257 | } |
258 | |
259 | /* Get current perf-probe event names */ |
260 | struct strlist *probe_file__get_namelist(int fd) |
261 | { |
262 | return __probe_file__get_namelist(fd, include_group: false); |
263 | } |
264 | |
265 | int probe_file__add_event(int fd, struct probe_trace_event *tev) |
266 | { |
267 | int ret = 0; |
268 | char *buf = synthesize_probe_trace_command(tev); |
269 | char sbuf[STRERR_BUFSIZE]; |
270 | |
271 | if (!buf) { |
272 | pr_debug("Failed to synthesize probe trace event.\n" ); |
273 | return -EINVAL; |
274 | } |
275 | |
276 | pr_debug("Writing event: %s\n" , buf); |
277 | if (!probe_event_dry_run) { |
278 | if (write(fd, buf, strlen(buf)) < (int)strlen(buf)) { |
279 | ret = -errno; |
280 | pr_warning("Failed to write event: %s\n" , |
281 | str_error_r(errno, sbuf, sizeof(sbuf))); |
282 | } |
283 | } |
284 | free(buf); |
285 | |
286 | return ret; |
287 | } |
288 | |
289 | static int __del_trace_probe_event(int fd, struct str_node *ent) |
290 | { |
291 | char *p; |
292 | char buf[128]; |
293 | int ret; |
294 | |
295 | /* Convert from perf-probe event to trace-probe event */ |
296 | ret = e_snprintf(str: buf, size: 128, format: "-:%s" , ent->s); |
297 | if (ret < 0) |
298 | goto error; |
299 | |
300 | p = strchr(buf + 2, ':'); |
301 | if (!p) { |
302 | pr_debug("Internal error: %s should have ':' but not.\n" , |
303 | ent->s); |
304 | ret = -ENOTSUP; |
305 | goto error; |
306 | } |
307 | *p = '/'; |
308 | |
309 | pr_debug("Writing event: %s\n" , buf); |
310 | ret = write(fd, buf, strlen(buf)); |
311 | if (ret < 0) { |
312 | ret = -errno; |
313 | goto error; |
314 | } |
315 | |
316 | return 0; |
317 | error: |
318 | pr_warning("Failed to delete event: %s\n" , |
319 | str_error_r(-ret, buf, sizeof(buf))); |
320 | return ret; |
321 | } |
322 | |
323 | int probe_file__get_events(int fd, struct strfilter *filter, |
324 | struct strlist *plist) |
325 | { |
326 | struct strlist *namelist; |
327 | struct str_node *ent; |
328 | const char *p; |
329 | int ret = -ENOENT; |
330 | |
331 | if (!plist) |
332 | return -EINVAL; |
333 | |
334 | namelist = __probe_file__get_namelist(fd, include_group: true); |
335 | if (!namelist) |
336 | return -ENOENT; |
337 | |
338 | strlist__for_each_entry(ent, namelist) { |
339 | p = strchr(ent->s, ':'); |
340 | if ((p && strfilter__compare(filter, str: p + 1)) || |
341 | strfilter__compare(filter, str: ent->s)) { |
342 | ret = strlist__add(slist: plist, str: ent->s); |
343 | if (ret == -ENOMEM) { |
344 | pr_err("strlist__add failed with -ENOMEM\n" ); |
345 | goto out; |
346 | } |
347 | ret = 0; |
348 | } |
349 | } |
350 | out: |
351 | strlist__delete(slist: namelist); |
352 | |
353 | return ret; |
354 | } |
355 | |
356 | int probe_file__del_strlist(int fd, struct strlist *namelist) |
357 | { |
358 | int ret = 0; |
359 | struct str_node *ent; |
360 | |
361 | strlist__for_each_entry(ent, namelist) { |
362 | ret = __del_trace_probe_event(fd, ent); |
363 | if (ret < 0) |
364 | break; |
365 | } |
366 | return ret; |
367 | } |
368 | |
369 | int probe_file__del_events(int fd, struct strfilter *filter) |
370 | { |
371 | struct strlist *namelist; |
372 | int ret; |
373 | |
374 | namelist = strlist__new(NULL, NULL); |
375 | if (!namelist) |
376 | return -ENOMEM; |
377 | |
378 | ret = probe_file__get_events(fd, filter, plist: namelist); |
379 | if (ret < 0) |
380 | goto out; |
381 | |
382 | ret = probe_file__del_strlist(fd, namelist); |
383 | out: |
384 | strlist__delete(slist: namelist); |
385 | return ret; |
386 | } |
387 | |
388 | /* Caller must ensure to remove this entry from list */ |
389 | static void probe_cache_entry__delete(struct probe_cache_entry *entry) |
390 | { |
391 | if (entry) { |
392 | BUG_ON(!list_empty(&entry->node)); |
393 | |
394 | strlist__delete(slist: entry->tevlist); |
395 | clear_perf_probe_event(pev: &entry->pev); |
396 | zfree(&entry->spev); |
397 | free(entry); |
398 | } |
399 | } |
400 | |
401 | static struct probe_cache_entry * |
402 | probe_cache_entry__new(struct perf_probe_event *pev) |
403 | { |
404 | struct probe_cache_entry *entry = zalloc(sizeof(*entry)); |
405 | |
406 | if (entry) { |
407 | INIT_LIST_HEAD(list: &entry->node); |
408 | entry->tevlist = strlist__new(NULL, NULL); |
409 | if (!entry->tevlist) |
410 | zfree(&entry); |
411 | else if (pev) { |
412 | entry->spev = synthesize_perf_probe_command(pev); |
413 | if (!entry->spev || |
414 | perf_probe_event__copy(dst: &entry->pev, src: pev) < 0) { |
415 | probe_cache_entry__delete(entry); |
416 | return NULL; |
417 | } |
418 | } |
419 | } |
420 | |
421 | return entry; |
422 | } |
423 | |
424 | int probe_cache_entry__get_event(struct probe_cache_entry *entry, |
425 | struct probe_trace_event **tevs) |
426 | { |
427 | struct probe_trace_event *tev; |
428 | struct str_node *node; |
429 | int ret, i; |
430 | |
431 | ret = strlist__nr_entries(slist: entry->tevlist); |
432 | if (ret > probe_conf.max_probes) |
433 | return -E2BIG; |
434 | |
435 | *tevs = zalloc(ret * sizeof(*tev)); |
436 | if (!*tevs) |
437 | return -ENOMEM; |
438 | |
439 | i = 0; |
440 | strlist__for_each_entry(node, entry->tevlist) { |
441 | tev = &(*tevs)[i++]; |
442 | ret = parse_probe_trace_command(cmd: node->s, tev); |
443 | if (ret < 0) |
444 | break; |
445 | } |
446 | return i; |
447 | } |
448 | |
449 | /* For the kernel probe caches, pass target = NULL or DSO__NAME_KALLSYMS */ |
450 | static int probe_cache__open(struct probe_cache *pcache, const char *target, |
451 | struct nsinfo *nsi) |
452 | { |
453 | char cpath[PATH_MAX]; |
454 | char sbuildid[SBUILD_ID_SIZE]; |
455 | char *dir_name = NULL; |
456 | bool is_kallsyms = false; |
457 | int ret, fd; |
458 | struct nscookie nsc; |
459 | |
460 | if (target && build_id_cache__cached(sbuild_id: target)) { |
461 | /* This is a cached buildid */ |
462 | strlcpy(sbuildid, target, SBUILD_ID_SIZE); |
463 | dir_name = build_id_cache__linkname(sbuild_id: sbuildid, NULL, size: 0); |
464 | goto found; |
465 | } |
466 | |
467 | if (!target || !strcmp(target, DSO__NAME_KALLSYMS)) { |
468 | target = DSO__NAME_KALLSYMS; |
469 | is_kallsyms = true; |
470 | ret = sysfs__sprintf_build_id(root_dir: "/" , sbuild_id: sbuildid); |
471 | } else { |
472 | nsinfo__mountns_enter(nsi, nc: &nsc); |
473 | ret = filename__sprintf_build_id(pathname: target, sbuild_id: sbuildid); |
474 | nsinfo__mountns_exit(nc: &nsc); |
475 | } |
476 | |
477 | if (ret < 0) { |
478 | pr_debug("Failed to get build-id from %s.\n" , target); |
479 | return ret; |
480 | } |
481 | |
482 | /* If we have no buildid cache, make it */ |
483 | if (!build_id_cache__cached(sbuild_id: sbuildid)) { |
484 | ret = build_id_cache__add_s(sbuild_id: sbuildid, name: target, nsi, |
485 | is_kallsyms, NULL); |
486 | if (ret < 0) { |
487 | pr_debug("Failed to add build-id cache: %s\n" , target); |
488 | return ret; |
489 | } |
490 | } |
491 | |
492 | dir_name = build_id_cache__cachedir(sbuild_id: sbuildid, name: target, nsi, is_kallsyms, |
493 | is_vdso: false); |
494 | found: |
495 | if (!dir_name) { |
496 | pr_debug("Failed to get cache from %s\n" , target); |
497 | return -ENOMEM; |
498 | } |
499 | |
500 | snprintf(buf: cpath, PATH_MAX, fmt: "%s/probes" , dir_name); |
501 | fd = open(cpath, O_CREAT | O_RDWR, 0644); |
502 | if (fd < 0) |
503 | pr_debug("Failed to open cache(%d): %s\n" , fd, cpath); |
504 | free(dir_name); |
505 | pcache->fd = fd; |
506 | |
507 | return fd; |
508 | } |
509 | |
510 | static int probe_cache__load(struct probe_cache *pcache) |
511 | { |
512 | struct probe_cache_entry *entry = NULL; |
513 | char buf[MAX_CMDLEN], *p; |
514 | int ret = 0, fddup; |
515 | FILE *fp; |
516 | |
517 | fddup = dup(pcache->fd); |
518 | if (fddup < 0) |
519 | return -errno; |
520 | fp = fdopen(fddup, "r" ); |
521 | if (!fp) { |
522 | close(fddup); |
523 | return -EINVAL; |
524 | } |
525 | |
526 | while (!feof(fp)) { |
527 | if (!fgets(buf, MAX_CMDLEN, fp)) |
528 | break; |
529 | p = strchr(buf, '\n'); |
530 | if (p) |
531 | *p = '\0'; |
532 | /* #perf_probe_event or %sdt_event */ |
533 | if (buf[0] == '#' || buf[0] == '%') { |
534 | entry = probe_cache_entry__new(NULL); |
535 | if (!entry) { |
536 | ret = -ENOMEM; |
537 | goto out; |
538 | } |
539 | if (buf[0] == '%') |
540 | entry->sdt = true; |
541 | entry->spev = strdup(buf + 1); |
542 | if (entry->spev) |
543 | ret = parse_perf_probe_command(cmd: buf + 1, |
544 | pev: &entry->pev); |
545 | else |
546 | ret = -ENOMEM; |
547 | if (ret < 0) { |
548 | probe_cache_entry__delete(entry); |
549 | goto out; |
550 | } |
551 | list_add_tail(new: &entry->node, head: &pcache->entries); |
552 | } else { /* trace_probe_event */ |
553 | if (!entry) { |
554 | ret = -EINVAL; |
555 | goto out; |
556 | } |
557 | ret = strlist__add(slist: entry->tevlist, str: buf); |
558 | if (ret == -ENOMEM) { |
559 | pr_err("strlist__add failed with -ENOMEM\n" ); |
560 | goto out; |
561 | } |
562 | } |
563 | } |
564 | out: |
565 | fclose(fp); |
566 | return ret; |
567 | } |
568 | |
569 | static struct probe_cache *probe_cache__alloc(void) |
570 | { |
571 | struct probe_cache *pcache = zalloc(sizeof(*pcache)); |
572 | |
573 | if (pcache) { |
574 | INIT_LIST_HEAD(list: &pcache->entries); |
575 | pcache->fd = -EINVAL; |
576 | } |
577 | return pcache; |
578 | } |
579 | |
580 | void probe_cache__purge(struct probe_cache *pcache) |
581 | { |
582 | struct probe_cache_entry *entry, *n; |
583 | |
584 | list_for_each_entry_safe(entry, n, &pcache->entries, node) { |
585 | list_del_init(entry: &entry->node); |
586 | probe_cache_entry__delete(entry); |
587 | } |
588 | } |
589 | |
590 | void probe_cache__delete(struct probe_cache *pcache) |
591 | { |
592 | if (!pcache) |
593 | return; |
594 | |
595 | probe_cache__purge(pcache); |
596 | if (pcache->fd > 0) |
597 | close(pcache->fd); |
598 | free(pcache); |
599 | } |
600 | |
601 | struct probe_cache *probe_cache__new(const char *target, struct nsinfo *nsi) |
602 | { |
603 | struct probe_cache *pcache = probe_cache__alloc(); |
604 | int ret; |
605 | |
606 | if (!pcache) |
607 | return NULL; |
608 | |
609 | ret = probe_cache__open(pcache, target, nsi); |
610 | if (ret < 0) { |
611 | pr_debug("Cache open error: %d\n" , ret); |
612 | goto out_err; |
613 | } |
614 | |
615 | ret = probe_cache__load(pcache); |
616 | if (ret < 0) { |
617 | pr_debug("Cache read error: %d\n" , ret); |
618 | goto out_err; |
619 | } |
620 | |
621 | return pcache; |
622 | |
623 | out_err: |
624 | probe_cache__delete(pcache); |
625 | return NULL; |
626 | } |
627 | |
628 | static bool streql(const char *a, const char *b) |
629 | { |
630 | if (a == b) |
631 | return true; |
632 | |
633 | if (!a || !b) |
634 | return false; |
635 | |
636 | return !strcmp(a, b); |
637 | } |
638 | |
639 | struct probe_cache_entry * |
640 | probe_cache__find(struct probe_cache *pcache, struct perf_probe_event *pev) |
641 | { |
642 | struct probe_cache_entry *entry = NULL; |
643 | char *cmd = synthesize_perf_probe_command(pev); |
644 | |
645 | if (!cmd) |
646 | return NULL; |
647 | |
648 | for_each_probe_cache_entry(entry, pcache) { |
649 | if (pev->sdt) { |
650 | if (entry->pev.event && |
651 | streql(a: entry->pev.event, b: pev->event) && |
652 | (!pev->group || |
653 | streql(a: entry->pev.group, b: pev->group))) |
654 | goto found; |
655 | |
656 | continue; |
657 | } |
658 | /* Hit if same event name or same command-string */ |
659 | if ((pev->event && |
660 | (streql(a: entry->pev.group, b: pev->group) && |
661 | streql(a: entry->pev.event, b: pev->event))) || |
662 | (!strcmp(entry->spev, cmd))) |
663 | goto found; |
664 | } |
665 | entry = NULL; |
666 | |
667 | found: |
668 | free(cmd); |
669 | return entry; |
670 | } |
671 | |
672 | struct probe_cache_entry * |
673 | probe_cache__find_by_name(struct probe_cache *pcache, |
674 | const char *group, const char *event) |
675 | { |
676 | struct probe_cache_entry *entry = NULL; |
677 | |
678 | for_each_probe_cache_entry(entry, pcache) { |
679 | /* Hit if same event name or same command-string */ |
680 | if (streql(a: entry->pev.group, b: group) && |
681 | streql(a: entry->pev.event, b: event)) |
682 | goto found; |
683 | } |
684 | entry = NULL; |
685 | |
686 | found: |
687 | return entry; |
688 | } |
689 | |
690 | int probe_cache__add_entry(struct probe_cache *pcache, |
691 | struct perf_probe_event *pev, |
692 | struct probe_trace_event *tevs, int ntevs) |
693 | { |
694 | struct probe_cache_entry *entry = NULL; |
695 | char *command; |
696 | int i, ret = 0; |
697 | |
698 | if (!pcache || !pev || !tevs || ntevs <= 0) { |
699 | ret = -EINVAL; |
700 | goto out_err; |
701 | } |
702 | |
703 | /* Remove old cache entry */ |
704 | entry = probe_cache__find(pcache, pev); |
705 | if (entry) { |
706 | list_del_init(entry: &entry->node); |
707 | probe_cache_entry__delete(entry); |
708 | } |
709 | |
710 | ret = -ENOMEM; |
711 | entry = probe_cache_entry__new(pev); |
712 | if (!entry) |
713 | goto out_err; |
714 | |
715 | for (i = 0; i < ntevs; i++) { |
716 | if (!tevs[i].point.symbol) |
717 | continue; |
718 | |
719 | command = synthesize_probe_trace_command(tev: &tevs[i]); |
720 | if (!command) |
721 | goto out_err; |
722 | ret = strlist__add(slist: entry->tevlist, str: command); |
723 | if (ret == -ENOMEM) { |
724 | pr_err("strlist__add failed with -ENOMEM\n" ); |
725 | goto out_err; |
726 | } |
727 | |
728 | free(command); |
729 | } |
730 | list_add_tail(new: &entry->node, head: &pcache->entries); |
731 | pr_debug("Added probe cache: %d\n" , ntevs); |
732 | return 0; |
733 | |
734 | out_err: |
735 | pr_debug("Failed to add probe caches\n" ); |
736 | probe_cache_entry__delete(entry); |
737 | return ret; |
738 | } |
739 | |
740 | #ifdef HAVE_GELF_GETNOTE_SUPPORT |
741 | static unsigned long long sdt_note__get_addr(struct sdt_note *note) |
742 | { |
743 | return note->bit32 ? |
744 | (unsigned long long)note->addr.a32[SDT_NOTE_IDX_LOC] : |
745 | (unsigned long long)note->addr.a64[SDT_NOTE_IDX_LOC]; |
746 | } |
747 | |
748 | static unsigned long long sdt_note__get_ref_ctr_offset(struct sdt_note *note) |
749 | { |
750 | return note->bit32 ? |
751 | (unsigned long long)note->addr.a32[SDT_NOTE_IDX_REFCTR] : |
752 | (unsigned long long)note->addr.a64[SDT_NOTE_IDX_REFCTR]; |
753 | } |
754 | |
755 | static const char * const type_to_suffix[] = { |
756 | ":s64" , "" , "" , "" , ":s32" , "" , ":s16" , ":s8" , |
757 | "" , ":u8" , ":u16" , "" , ":u32" , "" , "" , "" , ":u64" |
758 | }; |
759 | |
760 | /* |
761 | * Isolate the string number and convert it into a decimal value; |
762 | * this will be an index to get suffix of the uprobe name (defining |
763 | * the type) |
764 | */ |
765 | static int sdt_arg_parse_size(char *n_ptr, const char **suffix) |
766 | { |
767 | long type_idx; |
768 | |
769 | type_idx = strtol(n_ptr, NULL, 10); |
770 | if (type_idx < -8 || type_idx > 8) { |
771 | pr_debug4("Failed to get a valid sdt type\n" ); |
772 | return -1; |
773 | } |
774 | |
775 | *suffix = type_to_suffix[type_idx + 8]; |
776 | return 0; |
777 | } |
778 | |
779 | static int synthesize_sdt_probe_arg(struct strbuf *buf, int i, const char *arg) |
780 | { |
781 | char *op, *desc = strdup(arg), *new_op = NULL; |
782 | const char *suffix = "" ; |
783 | int ret = -1; |
784 | |
785 | if (desc == NULL) { |
786 | pr_debug4("Allocation error\n" ); |
787 | return ret; |
788 | } |
789 | |
790 | /* |
791 | * Argument is in N@OP format. N is size of the argument and OP is |
792 | * the actual assembly operand. N can be omitted; in that case |
793 | * argument is just OP(without @). |
794 | */ |
795 | op = strchr(desc, '@'); |
796 | if (op) { |
797 | op[0] = '\0'; |
798 | op++; |
799 | |
800 | if (sdt_arg_parse_size(desc, &suffix)) |
801 | goto error; |
802 | } else { |
803 | op = desc; |
804 | } |
805 | |
806 | ret = arch_sdt_arg_parse_op(op, &new_op); |
807 | |
808 | if (ret < 0) |
809 | goto error; |
810 | |
811 | if (ret == SDT_ARG_VALID) { |
812 | ret = strbuf_addf(buf, " arg%d=%s%s" , i + 1, new_op, suffix); |
813 | if (ret < 0) |
814 | goto error; |
815 | } |
816 | |
817 | ret = 0; |
818 | error: |
819 | free(desc); |
820 | free(new_op); |
821 | return ret; |
822 | } |
823 | |
824 | static char *synthesize_sdt_probe_command(struct sdt_note *note, |
825 | const char *pathname, |
826 | const char *sdtgrp) |
827 | { |
828 | struct strbuf buf; |
829 | char *ret = NULL; |
830 | int i, args_count, err; |
831 | unsigned long long ref_ctr_offset; |
832 | char *arg; |
833 | int arg_idx = 0; |
834 | |
835 | if (strbuf_init(&buf, 32) < 0) |
836 | return NULL; |
837 | |
838 | err = strbuf_addf(&buf, "p:%s/%s %s:0x%llx" , |
839 | sdtgrp, note->name, pathname, |
840 | sdt_note__get_addr(note)); |
841 | |
842 | ref_ctr_offset = sdt_note__get_ref_ctr_offset(note); |
843 | if (ref_ctr_offset && err >= 0) |
844 | err = strbuf_addf(&buf, "(0x%llx)" , ref_ctr_offset); |
845 | |
846 | if (err < 0) |
847 | goto error; |
848 | |
849 | if (!note->args) |
850 | goto out; |
851 | |
852 | if (note->args) { |
853 | char **args = argv_split(note->args, &args_count); |
854 | |
855 | if (args == NULL) |
856 | goto error; |
857 | |
858 | for (i = 0; i < args_count; ) { |
859 | /* |
860 | * FIXUP: Arm64 ELF section '.note.stapsdt' uses string |
861 | * format "-4@[sp, NUM]" if a probe is to access data in |
862 | * the stack, e.g. below is an example for the SDT |
863 | * Arguments: |
864 | * |
865 | * Arguments: -4@[sp, 12] -4@[sp, 8] -4@[sp, 4] |
866 | * |
867 | * Since the string introduces an extra space character |
868 | * in the middle of square brackets, the argument is |
869 | * divided into two items. Fixup for this case, if an |
870 | * item contains sub string "[sp,", need to concatenate |
871 | * the two items. |
872 | */ |
873 | if (strstr(args[i], "[sp," ) && (i+1) < args_count) { |
874 | err = asprintf(&arg, "%s %s" , args[i], args[i+1]); |
875 | i += 2; |
876 | } else { |
877 | err = asprintf(&arg, "%s" , args[i]); |
878 | i += 1; |
879 | } |
880 | |
881 | /* Failed to allocate memory */ |
882 | if (err < 0) { |
883 | argv_free(args); |
884 | goto error; |
885 | } |
886 | |
887 | if (synthesize_sdt_probe_arg(&buf, arg_idx, arg) < 0) { |
888 | free(arg); |
889 | argv_free(args); |
890 | goto error; |
891 | } |
892 | |
893 | free(arg); |
894 | arg_idx++; |
895 | } |
896 | |
897 | argv_free(args); |
898 | } |
899 | |
900 | out: |
901 | ret = strbuf_detach(&buf, NULL); |
902 | error: |
903 | strbuf_release(&buf); |
904 | return ret; |
905 | } |
906 | |
907 | int probe_cache__scan_sdt(struct probe_cache *pcache, const char *pathname) |
908 | { |
909 | struct probe_cache_entry *entry = NULL; |
910 | struct list_head sdtlist; |
911 | struct sdt_note *note; |
912 | char *buf; |
913 | char sdtgrp[64]; |
914 | int ret; |
915 | |
916 | INIT_LIST_HEAD(&sdtlist); |
917 | ret = get_sdt_note_list(&sdtlist, pathname); |
918 | if (ret < 0) { |
919 | pr_debug4("Failed to get sdt note: %d\n" , ret); |
920 | return ret; |
921 | } |
922 | list_for_each_entry(note, &sdtlist, note_list) { |
923 | ret = snprintf(sdtgrp, 64, "sdt_%s" , note->provider); |
924 | if (ret < 0) |
925 | break; |
926 | /* Try to find same-name entry */ |
927 | entry = probe_cache__find_by_name(pcache, sdtgrp, note->name); |
928 | if (!entry) { |
929 | entry = probe_cache_entry__new(NULL); |
930 | if (!entry) { |
931 | ret = -ENOMEM; |
932 | break; |
933 | } |
934 | entry->sdt = true; |
935 | ret = asprintf(&entry->spev, "%s:%s=%s" , sdtgrp, |
936 | note->name, note->name); |
937 | if (ret < 0) |
938 | break; |
939 | entry->pev.event = strdup(note->name); |
940 | entry->pev.group = strdup(sdtgrp); |
941 | list_add_tail(&entry->node, &pcache->entries); |
942 | } |
943 | buf = synthesize_sdt_probe_command(note, pathname, sdtgrp); |
944 | if (!buf) { |
945 | ret = -ENOMEM; |
946 | break; |
947 | } |
948 | |
949 | ret = strlist__add(entry->tevlist, buf); |
950 | |
951 | free(buf); |
952 | entry = NULL; |
953 | |
954 | if (ret == -ENOMEM) { |
955 | pr_err("strlist__add failed with -ENOMEM\n" ); |
956 | break; |
957 | } |
958 | } |
959 | if (entry) { |
960 | list_del_init(&entry->node); |
961 | probe_cache_entry__delete(entry); |
962 | } |
963 | cleanup_sdt_note_list(&sdtlist); |
964 | return ret; |
965 | } |
966 | #endif |
967 | |
968 | static int probe_cache_entry__write(struct probe_cache_entry *entry, int fd) |
969 | { |
970 | struct str_node *snode; |
971 | struct stat st; |
972 | struct iovec iov[3]; |
973 | const char *prefix = entry->sdt ? "%" : "#" ; |
974 | int ret; |
975 | /* Save stat for rollback */ |
976 | ret = fstat(fd, &st); |
977 | if (ret < 0) |
978 | return ret; |
979 | |
980 | pr_debug("Writing cache: %s%s\n" , prefix, entry->spev); |
981 | iov[0].iov_base = (void *)prefix; iov[0].iov_len = 1; |
982 | iov[1].iov_base = entry->spev; iov[1].iov_len = strlen(entry->spev); |
983 | iov[2].iov_base = (void *)"\n" ; iov[2].iov_len = 1; |
984 | ret = writev(fd, iov, 3); |
985 | if (ret < (int)iov[1].iov_len + 2) |
986 | goto rollback; |
987 | |
988 | strlist__for_each_entry(snode, entry->tevlist) { |
989 | iov[0].iov_base = (void *)snode->s; |
990 | iov[0].iov_len = strlen(snode->s); |
991 | iov[1].iov_base = (void *)"\n" ; iov[1].iov_len = 1; |
992 | ret = writev(fd, iov, 2); |
993 | if (ret < (int)iov[0].iov_len + 1) |
994 | goto rollback; |
995 | } |
996 | return 0; |
997 | |
998 | rollback: |
999 | /* Rollback to avoid cache file corruption */ |
1000 | if (ret > 0) |
1001 | ret = -1; |
1002 | if (ftruncate(fd, st.st_size) < 0) |
1003 | ret = -2; |
1004 | |
1005 | return ret; |
1006 | } |
1007 | |
1008 | int probe_cache__commit(struct probe_cache *pcache) |
1009 | { |
1010 | struct probe_cache_entry *entry; |
1011 | int ret = 0; |
1012 | |
1013 | /* TBD: if we do not update existing entries, skip it */ |
1014 | ret = lseek(pcache->fd, 0, SEEK_SET); |
1015 | if (ret < 0) |
1016 | goto out; |
1017 | |
1018 | ret = ftruncate(pcache->fd, 0); |
1019 | if (ret < 0) |
1020 | goto out; |
1021 | |
1022 | for_each_probe_cache_entry(entry, pcache) { |
1023 | ret = probe_cache_entry__write(entry, fd: pcache->fd); |
1024 | pr_debug("Cache committed: %d\n" , ret); |
1025 | if (ret < 0) |
1026 | break; |
1027 | } |
1028 | out: |
1029 | return ret; |
1030 | } |
1031 | |
1032 | static bool probe_cache_entry__compare(struct probe_cache_entry *entry, |
1033 | struct strfilter *filter) |
1034 | { |
1035 | char buf[128], *ptr = entry->spev; |
1036 | |
1037 | if (entry->pev.event) { |
1038 | snprintf(buf, size: 128, fmt: "%s:%s" , entry->pev.group, entry->pev.event); |
1039 | ptr = buf; |
1040 | } |
1041 | return strfilter__compare(filter, str: ptr); |
1042 | } |
1043 | |
1044 | int probe_cache__filter_purge(struct probe_cache *pcache, |
1045 | struct strfilter *filter) |
1046 | { |
1047 | struct probe_cache_entry *entry, *tmp; |
1048 | |
1049 | list_for_each_entry_safe(entry, tmp, &pcache->entries, node) { |
1050 | if (probe_cache_entry__compare(entry, filter)) { |
1051 | pr_info("Removed cached event: %s\n" , entry->spev); |
1052 | list_del_init(entry: &entry->node); |
1053 | probe_cache_entry__delete(entry); |
1054 | } |
1055 | } |
1056 | return 0; |
1057 | } |
1058 | |
1059 | static int probe_cache__show_entries(struct probe_cache *pcache, |
1060 | struct strfilter *filter) |
1061 | { |
1062 | struct probe_cache_entry *entry; |
1063 | |
1064 | for_each_probe_cache_entry(entry, pcache) { |
1065 | if (probe_cache_entry__compare(entry, filter)) |
1066 | printf("%s\n" , entry->spev); |
1067 | } |
1068 | return 0; |
1069 | } |
1070 | |
1071 | /* Show all cached probes */ |
1072 | int probe_cache__show_all_caches(struct strfilter *filter) |
1073 | { |
1074 | struct probe_cache *pcache; |
1075 | struct strlist *bidlist; |
1076 | struct str_node *nd; |
1077 | char *buf = strfilter__string(filter); |
1078 | |
1079 | pr_debug("list cache with filter: %s\n" , buf); |
1080 | free(buf); |
1081 | |
1082 | bidlist = build_id_cache__list_all(validonly: true); |
1083 | if (!bidlist) { |
1084 | pr_debug("Failed to get buildids: %d\n" , errno); |
1085 | return -EINVAL; |
1086 | } |
1087 | strlist__for_each_entry(nd, bidlist) { |
1088 | pcache = probe_cache__new(nd->s, NULL); |
1089 | if (!pcache) |
1090 | continue; |
1091 | if (!list_empty(head: &pcache->entries)) { |
1092 | buf = build_id_cache__origname(sbuild_id: nd->s); |
1093 | printf("%s (%s):\n" , buf, nd->s); |
1094 | free(buf); |
1095 | probe_cache__show_entries(pcache, filter); |
1096 | } |
1097 | probe_cache__delete(pcache); |
1098 | } |
1099 | strlist__delete(slist: bidlist); |
1100 | |
1101 | return 0; |
1102 | } |
1103 | |
1104 | enum ftrace_readme { |
1105 | FTRACE_README_PROBE_TYPE_X = 0, |
1106 | FTRACE_README_KRETPROBE_OFFSET, |
1107 | FTRACE_README_UPROBE_REF_CTR, |
1108 | FTRACE_README_USER_ACCESS, |
1109 | FTRACE_README_MULTIPROBE_EVENT, |
1110 | FTRACE_README_IMMEDIATE_VALUE, |
1111 | FTRACE_README_END, |
1112 | }; |
1113 | |
1114 | static struct { |
1115 | const char *pattern; |
1116 | bool avail; |
1117 | } ftrace_readme_table[] = { |
1118 | #define DEFINE_TYPE(idx, pat) \ |
1119 | [idx] = {.pattern = pat, .avail = false} |
1120 | DEFINE_TYPE(FTRACE_README_PROBE_TYPE_X, "*type: * x8/16/32/64,*" ), |
1121 | DEFINE_TYPE(FTRACE_README_KRETPROBE_OFFSET, "*place (kretprobe): *" ), |
1122 | DEFINE_TYPE(FTRACE_README_UPROBE_REF_CTR, "*ref_ctr_offset*" ), |
1123 | DEFINE_TYPE(FTRACE_README_USER_ACCESS, "*u]<offset>*" ), |
1124 | DEFINE_TYPE(FTRACE_README_MULTIPROBE_EVENT, "*Create/append/*" ), |
1125 | DEFINE_TYPE(FTRACE_README_IMMEDIATE_VALUE, "*\\imm-value,*" ), |
1126 | }; |
1127 | |
1128 | static bool scan_ftrace_readme(enum ftrace_readme type) |
1129 | { |
1130 | int fd; |
1131 | FILE *fp; |
1132 | char *buf = NULL; |
1133 | size_t len = 0; |
1134 | bool ret = false; |
1135 | static bool scanned = false; |
1136 | |
1137 | if (scanned) |
1138 | goto result; |
1139 | |
1140 | fd = open_trace_file(trace_file: "README" , readwrite: false); |
1141 | if (fd < 0) |
1142 | return ret; |
1143 | |
1144 | fp = fdopen(fd, "r" ); |
1145 | if (!fp) { |
1146 | close(fd); |
1147 | return ret; |
1148 | } |
1149 | |
1150 | while (getline(&buf, &len, fp) > 0) |
1151 | for (enum ftrace_readme i = 0; i < FTRACE_README_END; i++) |
1152 | if (!ftrace_readme_table[i].avail) |
1153 | ftrace_readme_table[i].avail = |
1154 | strglobmatch(str: buf, pat: ftrace_readme_table[i].pattern); |
1155 | scanned = true; |
1156 | |
1157 | fclose(fp); |
1158 | free(buf); |
1159 | |
1160 | result: |
1161 | if (type >= FTRACE_README_END) |
1162 | return false; |
1163 | |
1164 | return ftrace_readme_table[type].avail; |
1165 | } |
1166 | |
1167 | bool probe_type_is_available(enum probe_type type) |
1168 | { |
1169 | if (type >= PROBE_TYPE_END) |
1170 | return false; |
1171 | else if (type == PROBE_TYPE_X) |
1172 | return scan_ftrace_readme(type: FTRACE_README_PROBE_TYPE_X); |
1173 | |
1174 | return true; |
1175 | } |
1176 | |
1177 | bool kretprobe_offset_is_supported(void) |
1178 | { |
1179 | return scan_ftrace_readme(type: FTRACE_README_KRETPROBE_OFFSET); |
1180 | } |
1181 | |
1182 | bool uprobe_ref_ctr_is_supported(void) |
1183 | { |
1184 | return scan_ftrace_readme(type: FTRACE_README_UPROBE_REF_CTR); |
1185 | } |
1186 | |
1187 | bool user_access_is_supported(void) |
1188 | { |
1189 | return scan_ftrace_readme(type: FTRACE_README_USER_ACCESS); |
1190 | } |
1191 | |
1192 | bool multiprobe_event_is_supported(void) |
1193 | { |
1194 | return scan_ftrace_readme(type: FTRACE_README_MULTIPROBE_EVENT); |
1195 | } |
1196 | |
1197 | bool immediate_value_is_supported(void) |
1198 | { |
1199 | return scan_ftrace_readme(type: FTRACE_README_IMMEDIATE_VALUE); |
1200 | } |
1201 | |