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