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