Merge tag 'linux-kselftest-kunit-5.15-rc1' of git://git.kernel.org/pub/scm/linux...
[linux-2.6-microblaze.git] / tools / perf / util / probe-file.c
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(uprobe ? 0 : err, 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(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(buf, PATH_MAX, "%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("kprobe_events", readwrite);
131 }
132
133 static int open_uprobe_events(bool readwrite)
134 {
135         return open_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(flag & PF_FL_RW);
144         else
145                 fd = open_kprobe_events(flag & PF_FL_RW);
146         if (fd < 0)
147                 print_open_warning(fd, flag & PF_FL_UPROBE, 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(flag & PF_FL_RW);
158         *ufd = open_uprobe_events(flag & PF_FL_RW);
159         if (*kfd < 0 && *ufd < 0) {
160                 print_both_open_warning(*kfd, *ufd, 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(sl, 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(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(ent->s, &tev);
234                 if (ret < 0)
235                         break;
236                 if (include_group) {
237                         ret = e_snprintf(buf, 128, "%s:%s", tev.group,
238                                         tev.event);
239                         if (ret >= 0)
240                                 ret = strlist__add(sl, buf);
241                 } else
242                         ret = strlist__add(sl, tev.event);
243                 clear_probe_trace_event(&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(rawlist);
251
252         if (ret < 0) {
253                 strlist__delete(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, 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(buf, 128, "-:%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, 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, p + 1)) ||
341                     strfilter__compare(filter, ent->s)) {
342                         ret = strlist__add(plist, 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(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, namelist);
379         if (ret < 0)
380                 goto out;
381
382         ret = probe_file__del_strlist(fd, namelist);
383 out:
384         strlist__delete(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(entry->tevlist);
395                 clear_perf_probe_event(&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(&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(&entry->pev, 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(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(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(target)) {
461                 /* This is a cached buildid */
462                 strlcpy(sbuildid, target, SBUILD_ID_SIZE);
463                 dir_name = build_id_cache__linkname(sbuildid, NULL, 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("/", sbuildid);
471         } else {
472                 nsinfo__mountns_enter(nsi, &nsc);
473                 ret = filename__sprintf_build_id(target, sbuildid);
474                 nsinfo__mountns_exit(&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(sbuildid)) {
484                 ret = build_id_cache__add_s(sbuildid, 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(sbuildid, target, nsi, is_kallsyms,
493                                             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(cpath, PATH_MAX, "%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(buf + 1,
544                                                                 &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(&entry->node, &pcache->entries);
552                 } else {        /* trace_probe_event */
553                         if (!entry) {
554                                 ret = -EINVAL;
555                                 goto out;
556                         }
557                         ret = strlist__add(entry->tevlist, 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(&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->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(entry->pev.event, pev->event) &&
652                             (!pev->group ||
653                              streql(entry->pev.group, 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(entry->pev.group, pev->group) &&
661                       streql(entry->pev.event, 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(entry->pev.group, group) &&
681                     streql(entry->pev.event, 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->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(&tevs[i]);
720                 if (!command)
721                         goto out_err;
722                 ret = strlist__add(entry->tevlist, 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(&entry->node, &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, 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, 128, "%s:%s", entry->pev.group, entry->pev.event);
1039                 ptr = buf;
1040         }
1041         return strfilter__compare(filter, 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->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(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(&pcache->entries)) {
1092                         buf = build_id_cache__origname(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(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("README", 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(buf, 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(FTRACE_README_PROBE_TYPE_X);
1173
1174         return true;
1175 }
1176
1177 bool kretprobe_offset_is_supported(void)
1178 {
1179         return scan_ftrace_readme(FTRACE_README_KRETPROBE_OFFSET);
1180 }
1181
1182 bool uprobe_ref_ctr_is_supported(void)
1183 {
1184         return scan_ftrace_readme(FTRACE_README_UPROBE_REF_CTR);
1185 }
1186
1187 bool user_access_is_supported(void)
1188 {
1189         return scan_ftrace_readme(FTRACE_README_USER_ACCESS);
1190 }
1191
1192 bool multiprobe_event_is_supported(void)
1193 {
1194         return scan_ftrace_readme(FTRACE_README_MULTIPROBE_EVENT);
1195 }
1196
1197 bool immediate_value_is_supported(void)
1198 {
1199         return scan_ftrace_readme(FTRACE_README_IMMEDIATE_VALUE);
1200 }