2 * probe-file.c : operate ftrace k/uprobe events files
4 * Written by Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
19 #include <sys/types.h>
25 #include "strfilter.h"
31 #include <api/fs/tracing_path.h>
32 #include "probe-event.h"
33 #include "probe-file.h"
35 #include "perf_regs.h"
38 /* 4096 - 2 ('\n' + '\0') */
39 #define MAX_CMDLEN 4094
41 static void print_open_warning(int err, bool uprobe)
43 char sbuf[STRERR_BUFSIZE];
49 config = "CONFIG_UPROBE_EVENTS";
51 config = "CONFIG_KPROBE_EVENTS";
53 pr_warning("%cprobe_events file does not exist"
54 " - please rebuild kernel with %s.\n",
55 uprobe ? 'u' : 'k', config);
56 } else if (err == -ENOTSUP)
57 pr_warning("Tracefs or debugfs is not mounted.\n");
59 pr_warning("Failed to open %cprobe_events: %s\n",
61 str_error_r(-err, sbuf, sizeof(sbuf)));
64 static void print_both_open_warning(int kerr, int uerr)
66 /* Both kprobes and uprobes are disabled, warn it. */
67 if (kerr == -ENOTSUP && uerr == -ENOTSUP)
68 pr_warning("Tracefs or debugfs is not mounted.\n");
69 else if (kerr == -ENOENT && uerr == -ENOENT)
70 pr_warning("Please rebuild kernel with CONFIG_KPROBE_EVENTS "
71 "or/and CONFIG_UPROBE_EVENTS.\n");
73 char sbuf[STRERR_BUFSIZE];
74 pr_warning("Failed to open kprobe events: %s.\n",
75 str_error_r(-kerr, sbuf, sizeof(sbuf)));
76 pr_warning("Failed to open uprobe events: %s.\n",
77 str_error_r(-uerr, sbuf, sizeof(sbuf)));
81 int open_trace_file(const char *trace_file, bool readwrite)
86 ret = e_snprintf(buf, PATH_MAX, "%s/%s",
87 tracing_path, trace_file);
89 pr_debug("Opening %s write=%d\n", buf, readwrite);
90 if (readwrite && !probe_event_dry_run)
91 ret = open(buf, O_RDWR | O_APPEND, 0);
93 ret = open(buf, O_RDONLY, 0);
101 static int open_kprobe_events(bool readwrite)
103 return open_trace_file("kprobe_events", readwrite);
106 static int open_uprobe_events(bool readwrite)
108 return open_trace_file("uprobe_events", readwrite);
111 int probe_file__open(int flag)
115 if (flag & PF_FL_UPROBE)
116 fd = open_uprobe_events(flag & PF_FL_RW);
118 fd = open_kprobe_events(flag & PF_FL_RW);
120 print_open_warning(fd, flag & PF_FL_UPROBE);
125 int probe_file__open_both(int *kfd, int *ufd, int flag)
130 *kfd = open_kprobe_events(flag & PF_FL_RW);
131 *ufd = open_uprobe_events(flag & PF_FL_RW);
132 if (*kfd < 0 && *ufd < 0) {
133 print_both_open_warning(*kfd, *ufd);
140 /* Get raw string list of current kprobe_events or uprobe_events */
141 struct strlist *probe_file__get_rawlist(int fd)
145 char buf[MAX_CMDLEN];
152 sl = strlist__new(NULL, NULL);
160 fp = fdopen(fddup, "r");
162 goto out_close_fddup;
165 p = fgets(buf, MAX_CMDLEN, fp);
172 ret = strlist__add(sl, buf);
174 pr_debug("strlist__add failed (%d)\n", ret);
192 static struct strlist *__probe_file__get_namelist(int fd, bool include_group)
195 struct strlist *sl, *rawlist;
196 struct str_node *ent;
197 struct probe_trace_event tev;
200 memset(&tev, 0, sizeof(tev));
201 rawlist = probe_file__get_rawlist(fd);
204 sl = strlist__new(NULL, NULL);
205 strlist__for_each_entry(ent, rawlist) {
206 ret = parse_probe_trace_command(ent->s, &tev);
210 ret = e_snprintf(buf, 128, "%s:%s", tev.group,
213 ret = strlist__add(sl, buf);
215 ret = strlist__add(sl, tev.event);
216 clear_probe_trace_event(&tev);
220 strlist__delete(rawlist);
229 /* Get current perf-probe event names */
230 struct strlist *probe_file__get_namelist(int fd)
232 return __probe_file__get_namelist(fd, false);
235 int probe_file__add_event(int fd, struct probe_trace_event *tev)
238 char *buf = synthesize_probe_trace_command(tev);
239 char sbuf[STRERR_BUFSIZE];
242 pr_debug("Failed to synthesize probe trace event.\n");
246 pr_debug("Writing event: %s\n", buf);
247 if (!probe_event_dry_run) {
248 if (write(fd, buf, strlen(buf)) < (int)strlen(buf)) {
250 pr_warning("Failed to write event: %s\n",
251 str_error_r(errno, sbuf, sizeof(sbuf)));
259 static int __del_trace_probe_event(int fd, struct str_node *ent)
265 /* Convert from perf-probe event to trace-probe event */
266 ret = e_snprintf(buf, 128, "-:%s", ent->s);
270 p = strchr(buf + 2, ':');
272 pr_debug("Internal error: %s should have ':' but not.\n",
279 pr_debug("Writing event: %s\n", buf);
280 ret = write(fd, buf, strlen(buf));
288 pr_warning("Failed to delete event: %s\n",
289 str_error_r(-ret, buf, sizeof(buf)));
293 int probe_file__get_events(int fd, struct strfilter *filter,
294 struct strlist *plist)
296 struct strlist *namelist;
297 struct str_node *ent;
304 namelist = __probe_file__get_namelist(fd, true);
308 strlist__for_each_entry(ent, namelist) {
309 p = strchr(ent->s, ':');
310 if ((p && strfilter__compare(filter, p + 1)) ||
311 strfilter__compare(filter, ent->s)) {
312 strlist__add(plist, ent->s);
316 strlist__delete(namelist);
321 int probe_file__del_strlist(int fd, struct strlist *namelist)
324 struct str_node *ent;
326 strlist__for_each_entry(ent, namelist) {
327 ret = __del_trace_probe_event(fd, ent);
334 int probe_file__del_events(int fd, struct strfilter *filter)
336 struct strlist *namelist;
339 namelist = strlist__new(NULL, NULL);
343 ret = probe_file__get_events(fd, filter, namelist);
347 ret = probe_file__del_strlist(fd, namelist);
349 strlist__delete(namelist);
353 /* Caller must ensure to remove this entry from list */
354 static void probe_cache_entry__delete(struct probe_cache_entry *entry)
357 BUG_ON(!list_empty(&entry->node));
359 strlist__delete(entry->tevlist);
360 clear_perf_probe_event(&entry->pev);
366 static struct probe_cache_entry *
367 probe_cache_entry__new(struct perf_probe_event *pev)
369 struct probe_cache_entry *entry = zalloc(sizeof(*entry));
372 INIT_LIST_HEAD(&entry->node);
373 entry->tevlist = strlist__new(NULL, NULL);
377 entry->spev = synthesize_perf_probe_command(pev);
379 perf_probe_event__copy(&entry->pev, pev) < 0) {
380 probe_cache_entry__delete(entry);
389 int probe_cache_entry__get_event(struct probe_cache_entry *entry,
390 struct probe_trace_event **tevs)
392 struct probe_trace_event *tev;
393 struct str_node *node;
396 ret = strlist__nr_entries(entry->tevlist);
397 if (ret > probe_conf.max_probes)
400 *tevs = zalloc(ret * sizeof(*tev));
405 strlist__for_each_entry(node, entry->tevlist) {
407 ret = parse_probe_trace_command(node->s, tev);
414 /* For the kernel probe caches, pass target = NULL or DSO__NAME_KALLSYMS */
415 static int probe_cache__open(struct probe_cache *pcache, const char *target,
418 char cpath[PATH_MAX];
419 char sbuildid[SBUILD_ID_SIZE];
420 char *dir_name = NULL;
421 bool is_kallsyms = false;
425 if (target && build_id_cache__cached(target)) {
426 /* This is a cached buildid */
427 strlcpy(sbuildid, target, SBUILD_ID_SIZE);
428 dir_name = build_id_cache__linkname(sbuildid, NULL, 0);
432 if (!target || !strcmp(target, DSO__NAME_KALLSYMS)) {
433 target = DSO__NAME_KALLSYMS;
435 ret = sysfs__sprintf_build_id("/", sbuildid);
437 nsinfo__mountns_enter(nsi, &nsc);
438 ret = filename__sprintf_build_id(target, sbuildid);
439 nsinfo__mountns_exit(&nsc);
443 pr_debug("Failed to get build-id from %s.\n", target);
447 /* If we have no buildid cache, make it */
448 if (!build_id_cache__cached(sbuildid)) {
449 ret = build_id_cache__add_s(sbuildid, target, nsi,
452 pr_debug("Failed to add build-id cache: %s\n", target);
457 dir_name = build_id_cache__cachedir(sbuildid, target, nsi, is_kallsyms,
461 pr_debug("Failed to get cache from %s\n", target);
465 snprintf(cpath, PATH_MAX, "%s/probes", dir_name);
466 fd = open(cpath, O_CREAT | O_RDWR, 0644);
468 pr_debug("Failed to open cache(%d): %s\n", fd, cpath);
475 static int probe_cache__load(struct probe_cache *pcache)
477 struct probe_cache_entry *entry = NULL;
478 char buf[MAX_CMDLEN], *p;
482 fddup = dup(pcache->fd);
485 fp = fdopen(fddup, "r");
492 if (!fgets(buf, MAX_CMDLEN, fp))
494 p = strchr(buf, '\n');
497 /* #perf_probe_event or %sdt_event */
498 if (buf[0] == '#' || buf[0] == '%') {
499 entry = probe_cache_entry__new(NULL);
506 entry->spev = strdup(buf + 1);
508 ret = parse_perf_probe_command(buf + 1,
513 probe_cache_entry__delete(entry);
516 list_add_tail(&entry->node, &pcache->entries);
517 } else { /* trace_probe_event */
522 strlist__add(entry->tevlist, buf);
530 static struct probe_cache *probe_cache__alloc(void)
532 struct probe_cache *pcache = zalloc(sizeof(*pcache));
535 INIT_LIST_HEAD(&pcache->entries);
536 pcache->fd = -EINVAL;
541 void probe_cache__purge(struct probe_cache *pcache)
543 struct probe_cache_entry *entry, *n;
545 list_for_each_entry_safe(entry, n, &pcache->entries, node) {
546 list_del_init(&entry->node);
547 probe_cache_entry__delete(entry);
551 void probe_cache__delete(struct probe_cache *pcache)
556 probe_cache__purge(pcache);
562 struct probe_cache *probe_cache__new(const char *target, struct nsinfo *nsi)
564 struct probe_cache *pcache = probe_cache__alloc();
570 ret = probe_cache__open(pcache, target, nsi);
572 pr_debug("Cache open error: %d\n", ret);
576 ret = probe_cache__load(pcache);
578 pr_debug("Cache read error: %d\n", ret);
585 probe_cache__delete(pcache);
589 static bool streql(const char *a, const char *b)
597 return !strcmp(a, b);
600 struct probe_cache_entry *
601 probe_cache__find(struct probe_cache *pcache, struct perf_probe_event *pev)
603 struct probe_cache_entry *entry = NULL;
604 char *cmd = synthesize_perf_probe_command(pev);
609 for_each_probe_cache_entry(entry, pcache) {
611 if (entry->pev.event &&
612 streql(entry->pev.event, pev->event) &&
614 streql(entry->pev.group, pev->group)))
619 /* Hit if same event name or same command-string */
621 (streql(entry->pev.group, pev->group) &&
622 streql(entry->pev.event, pev->event))) ||
623 (!strcmp(entry->spev, cmd)))
633 struct probe_cache_entry *
634 probe_cache__find_by_name(struct probe_cache *pcache,
635 const char *group, const char *event)
637 struct probe_cache_entry *entry = NULL;
639 for_each_probe_cache_entry(entry, pcache) {
640 /* Hit if same event name or same command-string */
641 if (streql(entry->pev.group, group) &&
642 streql(entry->pev.event, event))
651 int probe_cache__add_entry(struct probe_cache *pcache,
652 struct perf_probe_event *pev,
653 struct probe_trace_event *tevs, int ntevs)
655 struct probe_cache_entry *entry = NULL;
659 if (!pcache || !pev || !tevs || ntevs <= 0) {
664 /* Remove old cache entry */
665 entry = probe_cache__find(pcache, pev);
667 list_del_init(&entry->node);
668 probe_cache_entry__delete(entry);
672 entry = probe_cache_entry__new(pev);
676 for (i = 0; i < ntevs; i++) {
677 if (!tevs[i].point.symbol)
680 command = synthesize_probe_trace_command(&tevs[i]);
683 strlist__add(entry->tevlist, command);
686 list_add_tail(&entry->node, &pcache->entries);
687 pr_debug("Added probe cache: %d\n", ntevs);
691 pr_debug("Failed to add probe caches\n");
692 probe_cache_entry__delete(entry);
696 #ifdef HAVE_GELF_GETNOTE_SUPPORT
697 static unsigned long long sdt_note__get_addr(struct sdt_note *note)
699 return note->bit32 ? (unsigned long long)note->addr.a32[0]
700 : (unsigned long long)note->addr.a64[0];
703 static const char * const type_to_suffix[] = {
704 ":s64", "", "", "", ":s32", "", ":s16", ":s8",
705 "", ":u8", ":u16", "", ":u32", "", "", "", ":u64"
709 * Isolate the string number and convert it into a decimal value;
710 * this will be an index to get suffix of the uprobe name (defining
713 static int sdt_arg_parse_size(char *n_ptr, const char **suffix)
717 type_idx = strtol(n_ptr, NULL, 10);
718 if (type_idx < -8 || type_idx > 8) {
719 pr_debug4("Failed to get a valid sdt type\n");
723 *suffix = type_to_suffix[type_idx + 8];
727 static int synthesize_sdt_probe_arg(struct strbuf *buf, int i, const char *arg)
729 char *op, *desc = strdup(arg), *new_op = NULL;
730 const char *suffix = "";
734 pr_debug4("Allocation error\n");
739 * Argument is in N@OP format. N is size of the argument and OP is
740 * the actual assembly operand. N can be omitted; in that case
741 * argument is just OP(without @).
743 op = strchr(desc, '@');
748 if (sdt_arg_parse_size(desc, &suffix))
754 ret = arch_sdt_arg_parse_op(op, &new_op);
759 if (ret == SDT_ARG_VALID) {
760 ret = strbuf_addf(buf, " arg%d=%s%s", i + 1, new_op, suffix);
772 static char *synthesize_sdt_probe_command(struct sdt_note *note,
773 const char *pathname,
777 char *ret = NULL, **args;
780 if (strbuf_init(&buf, 32) < 0)
783 if (strbuf_addf(&buf, "p:%s/%s %s:0x%llx",
784 sdtgrp, note->name, pathname,
785 sdt_note__get_addr(note)) < 0)
792 args = argv_split(note->args, &args_count);
794 for (i = 0; i < args_count; ++i) {
795 if (synthesize_sdt_probe_arg(&buf, i, args[i]) < 0)
801 ret = strbuf_detach(&buf, NULL);
803 strbuf_release(&buf);
807 int probe_cache__scan_sdt(struct probe_cache *pcache, const char *pathname)
809 struct probe_cache_entry *entry = NULL;
810 struct list_head sdtlist;
811 struct sdt_note *note;
816 INIT_LIST_HEAD(&sdtlist);
817 ret = get_sdt_note_list(&sdtlist, pathname);
819 pr_debug4("Failed to get sdt note: %d\n", ret);
822 list_for_each_entry(note, &sdtlist, note_list) {
823 ret = snprintf(sdtgrp, 64, "sdt_%s", note->provider);
826 /* Try to find same-name entry */
827 entry = probe_cache__find_by_name(pcache, sdtgrp, note->name);
829 entry = probe_cache_entry__new(NULL);
835 ret = asprintf(&entry->spev, "%s:%s=%s", sdtgrp,
836 note->name, note->name);
839 entry->pev.event = strdup(note->name);
840 entry->pev.group = strdup(sdtgrp);
841 list_add_tail(&entry->node, &pcache->entries);
843 buf = synthesize_sdt_probe_command(note, pathname, sdtgrp);
849 strlist__add(entry->tevlist, buf);
854 list_del_init(&entry->node);
855 probe_cache_entry__delete(entry);
857 cleanup_sdt_note_list(&sdtlist);
862 static int probe_cache_entry__write(struct probe_cache_entry *entry, int fd)
864 struct str_node *snode;
867 const char *prefix = entry->sdt ? "%" : "#";
869 /* Save stat for rollback */
870 ret = fstat(fd, &st);
874 pr_debug("Writing cache: %s%s\n", prefix, entry->spev);
875 iov[0].iov_base = (void *)prefix; iov[0].iov_len = 1;
876 iov[1].iov_base = entry->spev; iov[1].iov_len = strlen(entry->spev);
877 iov[2].iov_base = (void *)"\n"; iov[2].iov_len = 1;
878 ret = writev(fd, iov, 3);
879 if (ret < (int)iov[1].iov_len + 2)
882 strlist__for_each_entry(snode, entry->tevlist) {
883 iov[0].iov_base = (void *)snode->s;
884 iov[0].iov_len = strlen(snode->s);
885 iov[1].iov_base = (void *)"\n"; iov[1].iov_len = 1;
886 ret = writev(fd, iov, 2);
887 if (ret < (int)iov[0].iov_len + 1)
893 /* Rollback to avoid cache file corruption */
896 if (ftruncate(fd, st.st_size) < 0)
902 int probe_cache__commit(struct probe_cache *pcache)
904 struct probe_cache_entry *entry;
907 /* TBD: if we do not update existing entries, skip it */
908 ret = lseek(pcache->fd, 0, SEEK_SET);
912 ret = ftruncate(pcache->fd, 0);
916 for_each_probe_cache_entry(entry, pcache) {
917 ret = probe_cache_entry__write(entry, pcache->fd);
918 pr_debug("Cache committed: %d\n", ret);
926 static bool probe_cache_entry__compare(struct probe_cache_entry *entry,
927 struct strfilter *filter)
929 char buf[128], *ptr = entry->spev;
931 if (entry->pev.event) {
932 snprintf(buf, 128, "%s:%s", entry->pev.group, entry->pev.event);
935 return strfilter__compare(filter, ptr);
938 int probe_cache__filter_purge(struct probe_cache *pcache,
939 struct strfilter *filter)
941 struct probe_cache_entry *entry, *tmp;
943 list_for_each_entry_safe(entry, tmp, &pcache->entries, node) {
944 if (probe_cache_entry__compare(entry, filter)) {
945 pr_info("Removed cached event: %s\n", entry->spev);
946 list_del_init(&entry->node);
947 probe_cache_entry__delete(entry);
953 static int probe_cache__show_entries(struct probe_cache *pcache,
954 struct strfilter *filter)
956 struct probe_cache_entry *entry;
958 for_each_probe_cache_entry(entry, pcache) {
959 if (probe_cache_entry__compare(entry, filter))
960 printf("%s\n", entry->spev);
965 /* Show all cached probes */
966 int probe_cache__show_all_caches(struct strfilter *filter)
968 struct probe_cache *pcache;
969 struct strlist *bidlist;
971 char *buf = strfilter__string(filter);
973 pr_debug("list cache with filter: %s\n", buf);
976 bidlist = build_id_cache__list_all(true);
978 pr_debug("Failed to get buildids: %d\n", errno);
981 strlist__for_each_entry(nd, bidlist) {
982 pcache = probe_cache__new(nd->s, NULL);
985 if (!list_empty(&pcache->entries)) {
986 buf = build_id_cache__origname(nd->s);
987 printf("%s (%s):\n", buf, nd->s);
989 probe_cache__show_entries(pcache, filter);
991 probe_cache__delete(pcache);
993 strlist__delete(bidlist);
999 FTRACE_README_PROBE_TYPE_X = 0,
1000 FTRACE_README_KRETPROBE_OFFSET,
1005 const char *pattern;
1007 } ftrace_readme_table[] = {
1008 #define DEFINE_TYPE(idx, pat) \
1009 [idx] = {.pattern = pat, .avail = false}
1010 DEFINE_TYPE(FTRACE_README_PROBE_TYPE_X, "*type: * x8/16/32/64,*"),
1011 DEFINE_TYPE(FTRACE_README_KRETPROBE_OFFSET, "*place (kretprobe): *"),
1014 static bool scan_ftrace_readme(enum ftrace_readme type)
1021 static bool scanned = false;
1026 fd = open_trace_file("README", false);
1030 fp = fdopen(fd, "r");
1036 while (getline(&buf, &len, fp) > 0)
1037 for (enum ftrace_readme i = 0; i < FTRACE_README_END; i++)
1038 if (!ftrace_readme_table[i].avail)
1039 ftrace_readme_table[i].avail =
1040 strglobmatch(buf, ftrace_readme_table[i].pattern);
1047 if (type >= FTRACE_README_END)
1050 return ftrace_readme_table[type].avail;
1053 bool probe_type_is_available(enum probe_type type)
1055 if (type >= PROBE_TYPE_END)
1057 else if (type == PROBE_TYPE_X)
1058 return scan_ftrace_readme(FTRACE_README_PROBE_TYPE_X);
1063 bool kretprobe_offset_is_supported(void)
1065 return scan_ftrace_readme(FTRACE_README_KRETPROBE_OFFSET);