tools/perf/util/probe-file.c

   1 /*
   2  * probe-file.c : operate ftrace k/uprobe events files
   3  *
   4  * Written by Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  */
  17 #include <sys/uio.h>
  18 #include "util.h"
  19 #include "event.h"
  20 #include "strlist.h"
  21 #include "debug.h"
  22 #include "cache.h"
  23 #include "color.h"
  24 #include "symbol.h"
  25 #include "thread.h"
  26 #include <api/fs/tracing_path.h>
  27 #include "probe-event.h"
  28 #include "probe-file.h"
  29 #include "session.h"
  30
  31 #define MAX_CMDLEN 256
  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 static int open_probe_events(const char *trace_file, bool readwrite)
  74 {
  75         char buf[PATH_MAX];
  76         const char *tracing_dir = "";
  77         int ret;
  78
  79         ret = e_snprintf(buf, PATH_MAX, "%s/%s%s",
  80                          tracing_path, tracing_dir, trace_file);
  81         if (ret >= 0) {
  82                 pr_debug("Opening %s write=%d\n", buf, readwrite);
  83                 if (readwrite && !probe_event_dry_run)
  84                         ret = open(buf, O_RDWR | O_APPEND, 0);
  85                 else
  86                         ret = open(buf, O_RDONLY, 0);
  87
  88                 if (ret < 0)
  89                         ret = -errno;
  90         }
  91         return ret;
  92 }
  93
  94 static int open_kprobe_events(bool readwrite)
  95 {
  96         return open_probe_events("kprobe_events", readwrite);
  97 }
  98
  99 static int open_uprobe_events(bool readwrite)
 100 {
 101         return open_probe_events("uprobe_events", readwrite);
 102 }
 103
 104 int probe_file__open(int flag)
 105 {
 106         int fd;
 107
 108         if (flag & PF_FL_UPROBE)
 109                 fd = open_uprobe_events(flag & PF_FL_RW);
 110         else
 111                 fd = open_kprobe_events(flag & PF_FL_RW);
 112         if (fd < 0)
 113                 print_open_warning(fd, flag & PF_FL_UPROBE);
 114
 115         return fd;
 116 }
 117
 118 int probe_file__open_both(int *kfd, int *ufd, int flag)
 119 {
 120         if (!kfd || !ufd)
 121                 return -EINVAL;
 122
 123         *kfd = open_kprobe_events(flag & PF_FL_RW);
 124         *ufd = open_uprobe_events(flag & PF_FL_RW);
 125         if (*kfd < 0 && *ufd < 0) {
 126                 print_both_open_warning(*kfd, *ufd);
 127                 return *kfd;
 128         }
 129
 130         return 0;
 131 }
 132
 133 /* Get raw string list of current kprobe_events  or uprobe_events */
 134 struct strlist *probe_file__get_rawlist(int fd)
 135 {
 136         int ret, idx, fddup;
 137         FILE *fp;
 138         char buf[MAX_CMDLEN];
 139         char *p;
 140         struct strlist *sl;
 141
 142         if (fd < 0)
 143                 return NULL;
 144
 145         sl = strlist__new(NULL, NULL);
 146         if (sl == NULL)
 147                 return NULL;
 148
 149         fddup = dup(fd);
 150         if (fddup < 0)
 151                 goto out_free_sl;
 152
 153         fp = fdopen(fddup, "r");
 154         if (!fp)
 155                 goto out_close_fddup;
 156
 157         while (!feof(fp)) {
 158                 p = fgets(buf, MAX_CMDLEN, fp);
 159                 if (!p)
 160                         break;
 161
 162                 idx = strlen(p) - 1;
 163                 if (p[idx] == '\n')
 164                         p[idx] = '\0';
 165                 ret = strlist__add(sl, buf);
 166                 if (ret < 0) {
 167                         pr_debug("strlist__add failed (%d)\n", ret);
 168                         goto out_close_fp;
 169                 }
 170         }
 171         fclose(fp);
 172
 173         return sl;
 174
 175 out_close_fp:
 176         fclose(fp);
 177         goto out_free_sl;
 178 out_close_fddup:
 179         close(fddup);
 180 out_free_sl:
 181         strlist__delete(sl);
 182         return NULL;
 183 }
 184
 185 static struct strlist *__probe_file__get_namelist(int fd, bool include_group)
 186 {
 187         char buf[128];
 188         struct strlist *sl, *rawlist;
 189         struct str_node *ent;
 190         struct probe_trace_event tev;
 191         int ret = 0;
 192
 193         memset(&tev, 0, sizeof(tev));
 194         rawlist = probe_file__get_rawlist(fd);
 195         if (!rawlist)
 196                 return NULL;
 197         sl = strlist__new(NULL, NULL);
 198         strlist__for_each_entry(ent, rawlist) {
 199                 ret = parse_probe_trace_command(ent->s, &tev);
 200                 if (ret < 0)
 201                         break;
 202                 if (include_group) {
 203                         ret = e_snprintf(buf, 128, "%s:%s", tev.group,
 204                                         tev.event);
 205                         if (ret >= 0)
 206                                 ret = strlist__add(sl, buf);
 207                 } else
 208                         ret = strlist__add(sl, tev.event);
 209                 clear_probe_trace_event(&tev);
 210                 if (ret < 0)
 211                         break;
 212         }
 213         strlist__delete(rawlist);
 214
 215         if (ret < 0) {
 216                 strlist__delete(sl);
 217                 return NULL;
 218         }
 219         return sl;
 220 }
 221
 222 /* Get current perf-probe event names */
 223 struct strlist *probe_file__get_namelist(int fd)
 224 {
 225         return __probe_file__get_namelist(fd, false);
 226 }
 227
 228 int probe_file__add_event(int fd, struct probe_trace_event *tev)
 229 {
 230         int ret = 0;
 231         char *buf = synthesize_probe_trace_command(tev);
 232         char sbuf[STRERR_BUFSIZE];
 233
 234         if (!buf) {
 235                 pr_debug("Failed to synthesize probe trace event.\n");
 236                 return -EINVAL;
 237         }
 238
 239         pr_debug("Writing event: %s\n", buf);
 240         if (!probe_event_dry_run) {
 241                 if (write(fd, buf, strlen(buf)) < (int)strlen(buf)) {
 242                         ret = -errno;
 243                         pr_warning("Failed to write event: %s\n",
 244                                    str_error_r(errno, sbuf, sizeof(sbuf)));
 245                 }
 246         }
 247         free(buf);
 248
 249         return ret;
 250 }
 251
 252 static int __del_trace_probe_event(int fd, struct str_node *ent)
 253 {
 254         char *p;
 255         char buf[128];
 256         int ret;
 257
 258         /* Convert from perf-probe event to trace-probe event */
 259         ret = e_snprintf(buf, 128, "-:%s", ent->s);
 260         if (ret < 0)
 261                 goto error;
 262
 263         p = strchr(buf + 2, ':');
 264         if (!p) {
 265                 pr_debug("Internal error: %s should have ':' but not.\n",
 266                          ent->s);
 267                 ret = -ENOTSUP;
 268                 goto error;
 269         }
 270         *p = '/';
 271
 272         pr_debug("Writing event: %s\n", buf);
 273         ret = write(fd, buf, strlen(buf));
 274         if (ret < 0) {
 275                 ret = -errno;
 276                 goto error;
 277         }
 278
 279         return 0;
 280 error:
 281         pr_warning("Failed to delete event: %s\n",
 282                    str_error_r(-ret, buf, sizeof(buf)));
 283         return ret;
 284 }
 285
 286 int probe_file__get_events(int fd, struct strfilter *filter,
 287                            struct strlist *plist)
 288 {
 289         struct strlist *namelist;
 290         struct str_node *ent;
 291         const char *p;
 292         int ret = -ENOENT;
 293
 294         if (!plist)
 295                 return -EINVAL;
 296
 297         namelist = __probe_file__get_namelist(fd, true);
 298         if (!namelist)
 299                 return -ENOENT;
 300
 301         strlist__for_each_entry(ent, namelist) {
 302                 p = strchr(ent->s, ':');
 303                 if ((p && strfilter__compare(filter, p + 1)) ||
 304                     strfilter__compare(filter, ent->s)) {
 305                         strlist__add(plist, ent->s);
 306                         ret = 0;
 307                 }
 308         }
 309         strlist__delete(namelist);
 310
 311         return ret;
 312 }
 313
 314 int probe_file__del_strlist(int fd, struct strlist *namelist)
 315 {
 316         int ret = 0;
 317         struct str_node *ent;
 318
 319         strlist__for_each_entry(ent, namelist) {
 320                 ret = __del_trace_probe_event(fd, ent);
 321                 if (ret < 0)
 322                         break;
 323         }
 324         return ret;
 325 }
 326
 327 int probe_file__del_events(int fd, struct strfilter *filter)
 328 {
 329         struct strlist *namelist;
 330         int ret;
 331
 332         namelist = strlist__new(NULL, NULL);
 333         if (!namelist)
 334                 return -ENOMEM;
 335
 336         ret = probe_file__get_events(fd, filter, namelist);
 337         if (ret < 0)
 338                 return ret;
 339
 340         ret = probe_file__del_strlist(fd, namelist);
 341         strlist__delete(namelist);
 342
 343         return ret;
 344 }
 345
 346 /* Caller must ensure to remove this entry from list */
 347 static void probe_cache_entry__delete(struct probe_cache_entry *entry)
 348 {
 349         if (entry) {
 350                 BUG_ON(!list_empty(&entry->node));
 351
 352                 strlist__delete(entry->tevlist);
 353                 clear_perf_probe_event(&entry->pev);
 354                 zfree(&entry->spev);
 355                 free(entry);
 356         }
 357 }
 358
 359 static struct probe_cache_entry *
 360 probe_cache_entry__new(struct perf_probe_event *pev)
 361 {
 362         struct probe_cache_entry *entry = zalloc(sizeof(*entry));
 363
 364         if (entry) {
 365                 INIT_LIST_HEAD(&entry->node);
 366                 entry->tevlist = strlist__new(NULL, NULL);
 367                 if (!entry->tevlist)
 368                         zfree(&entry);
 369                 else if (pev) {
 370                         entry->spev = synthesize_perf_probe_command(pev);
 371                         if (!entry->spev ||
 372                             perf_probe_event__copy(&entry->pev, pev) < 0) {
 373                                 probe_cache_entry__delete(entry);
 374                                 return NULL;
 375                         }
 376                 }
 377         }
 378
 379         return entry;
 380 }
 381
 382 int probe_cache_entry__get_event(struct probe_cache_entry *entry,
 383                                  struct probe_trace_event **tevs)
 384 {
 385         struct probe_trace_event *tev;
 386         struct str_node *node;
 387         int ret, i;
 388
 389         ret = strlist__nr_entries(entry->tevlist);
 390         if (ret > probe_conf.max_probes)
 391                 return -E2BIG;
 392
 393         *tevs = zalloc(ret * sizeof(*tev));
 394         if (!*tevs)
 395                 return -ENOMEM;
 396
 397         i = 0;
 398         strlist__for_each_entry(node, entry->tevlist) {
 399                 tev = &(*tevs)[i++];
 400                 ret = parse_probe_trace_command(node->s, tev);
 401                 if (ret < 0)
 402                         break;
 403         }
 404         return i;
 405 }
 406
 407 /* For the kernel probe caches, pass target = NULL or DSO__NAME_KALLSYMS */
 408 static int probe_cache__open(struct probe_cache *pcache, const char *target)
 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
 416         if (target && build_id_cache__cached(target)) {
 417                 /* This is a cached buildid */
 418                 strncpy(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                 ret = filename__sprintf_build_id(target, sbuildid);
 429
 430         if (ret < 0) {
 431                 pr_debug("Failed to get build-id from %s.\n", target);
 432                 return ret;
 433         }
 434
 435         /* If we have no buildid cache, make it */
 436         if (!build_id_cache__cached(sbuildid)) {
 437                 ret = build_id_cache__add_s(sbuildid, target,
 438                                             is_kallsyms, NULL);
 439                 if (ret < 0) {
 440                         pr_debug("Failed to add build-id cache: %s\n", target);
 441                         return ret;
 442                 }
 443         }
 444
 445         dir_name = build_id_cache__cachedir(sbuildid, target, is_kallsyms,
 446                                             false);
 447 found:
 448         if (!dir_name) {
 449                 pr_debug("Failed to get cache from %s\n", target);
 450                 return -ENOMEM;
 451         }
 452
 453         snprintf(cpath, PATH_MAX, "%s/probes", dir_name);
 454         fd = open(cpath, O_CREAT | O_RDWR, 0644);
 455         if (fd < 0)
 456                 pr_debug("Failed to open cache(%d): %s\n", fd, cpath);
 457         free(dir_name);
 458         pcache->fd = fd;
 459
 460         return fd;
 461 }
 462
 463 static int probe_cache__load(struct probe_cache *pcache)
 464 {
 465         struct probe_cache_entry *entry = NULL;
 466         char buf[MAX_CMDLEN], *p;
 467         int ret = 0, fddup;
 468         FILE *fp;
 469
 470         fddup = dup(pcache->fd);
 471         if (fddup < 0)
 472                 return -errno;
 473         fp = fdopen(fddup, "r");
 474         if (!fp) {
 475                 close(fddup);
 476                 return -EINVAL;
 477         }
 478
 479         while (!feof(fp)) {
 480                 if (!fgets(buf, MAX_CMDLEN, fp))
 481                         break;
 482                 p = strchr(buf, '\n');
 483                 if (p)
 484                         *p = '\0';
 485                 /* #perf_probe_event or %sdt_event */
 486                 if (buf[0] == '#' || buf[0] == '%') {
 487                         entry = probe_cache_entry__new(NULL);
 488                         if (!entry) {
 489                                 ret = -ENOMEM;
 490                                 goto out;
 491                         }
 492                         if (buf[0] == '%')
 493                                 entry->sdt = true;
 494                         entry->spev = strdup(buf + 1);
 495                         if (entry->spev)
 496                                 ret = parse_perf_probe_command(buf + 1,
 497                                                                 &entry->pev);
 498                         else
 499                                 ret = -ENOMEM;
 500                         if (ret < 0) {
 501                                 probe_cache_entry__delete(entry);
 502                                 goto out;
 503                         }
 504                         list_add_tail(&entry->node, &pcache->entries);
 505                 } else {        /* trace_probe_event */
 506                         if (!entry) {
 507                                 ret = -EINVAL;
 508                                 goto out;
 509                         }
 510                         strlist__add(entry->tevlist, buf);
 511                 }
 512         }
 513 out:
 514         fclose(fp);
 515         return ret;
 516 }
 517
 518 static struct probe_cache *probe_cache__alloc(void)
 519 {
 520         struct probe_cache *pcache = zalloc(sizeof(*pcache));
 521
 522         if (pcache) {
 523                 INIT_LIST_HEAD(&pcache->entries);
 524                 pcache->fd = -EINVAL;
 525         }
 526         return pcache;
 527 }
 528
 529 void probe_cache__purge(struct probe_cache *pcache)
 530 {
 531         struct probe_cache_entry *entry, *n;
 532
 533         list_for_each_entry_safe(entry, n, &pcache->entries, node) {
 534                 list_del_init(&entry->node);
 535                 probe_cache_entry__delete(entry);
 536         }
 537 }
 538
 539 void probe_cache__delete(struct probe_cache *pcache)
 540 {
 541         if (!pcache)
 542                 return;
 543
 544         probe_cache__purge(pcache);
 545         if (pcache->fd > 0)
 546                 close(pcache->fd);
 547         free(pcache);
 548 }
 549
 550 struct probe_cache *probe_cache__new(const char *target)
 551 {
 552         struct probe_cache *pcache = probe_cache__alloc();
 553         int ret;
 554
 555         if (!pcache)
 556                 return NULL;
 557
 558         ret = probe_cache__open(pcache, target);
 559         if (ret < 0) {
 560                 pr_debug("Cache open error: %d\n", ret);
 561                 goto out_err;
 562         }
 563
 564         ret = probe_cache__load(pcache);
 565         if (ret < 0) {
 566                 pr_debug("Cache read error: %d\n", ret);
 567                 goto out_err;
 568         }
 569
 570         return pcache;
 571
 572 out_err:
 573         probe_cache__delete(pcache);
 574         return NULL;
 575 }
 576
 577 static bool streql(const char *a, const char *b)
 578 {
 579         if (a == b)
 580                 return true;
 581
 582         if (!a || !b)
 583                 return false;
 584
 585         return !strcmp(a, b);
 586 }
 587
 588 struct probe_cache_entry *
 589 probe_cache__find(struct probe_cache *pcache, struct perf_probe_event *pev)
 590 {
 591         struct probe_cache_entry *entry = NULL;
 592         char *cmd = synthesize_perf_probe_command(pev);
 593
 594         if (!cmd)
 595                 return NULL;
 596
 597         for_each_probe_cache_entry(entry, pcache) {
 598                 if (pev->sdt) {
 599                         if (entry->pev.event &&
 600                             streql(entry->pev.event, pev->event) &&
 601                             (!pev->group ||
 602                              streql(entry->pev.group, pev->group)))
 603                                 goto found;
 604
 605                         continue;
 606                 }
 607                 /* Hit if same event name or same command-string */
 608                 if ((pev->event &&
 609                      (streql(entry->pev.group, pev->group) &&
 610                       streql(entry->pev.event, pev->event))) ||
 611                     (!strcmp(entry->spev, cmd)))
 612                         goto found;
 613         }
 614         entry = NULL;
 615
 616 found:
 617         free(cmd);
 618         return entry;
 619 }
 620
 621 struct probe_cache_entry *
 622 probe_cache__find_by_name(struct probe_cache *pcache,
 623                           const char *group, const char *event)
 624 {
 625         struct probe_cache_entry *entry = NULL;
 626
 627         for_each_probe_cache_entry(entry, pcache) {
 628                 /* Hit if same event name or same command-string */
 629                 if (streql(entry->pev.group, group) &&
 630                     streql(entry->pev.event, event))
 631                         goto found;
 632         }
 633         entry = NULL;
 634
 635 found:
 636         return entry;
 637 }
 638
 639 int probe_cache__add_entry(struct probe_cache *pcache,
 640                            struct perf_probe_event *pev,
 641                            struct probe_trace_event *tevs, int ntevs)
 642 {
 643         struct probe_cache_entry *entry = NULL;
 644         char *command;
 645         int i, ret = 0;
 646
 647         if (!pcache || !pev || !tevs || ntevs <= 0) {
 648                 ret = -EINVAL;
 649                 goto out_err;
 650         }
 651
 652         /* Remove old cache entry */
 653         entry = probe_cache__find(pcache, pev);
 654         if (entry) {
 655                 list_del_init(&entry->node);
 656                 probe_cache_entry__delete(entry);
 657         }
 658
 659         ret = -ENOMEM;
 660         entry = probe_cache_entry__new(pev);
 661         if (!entry)
 662                 goto out_err;
 663
 664         for (i = 0; i < ntevs; i++) {
 665                 if (!tevs[i].point.symbol)
 666                         continue;
 667
 668                 command = synthesize_probe_trace_command(&tevs[i]);
 669                 if (!command)
 670                         goto out_err;
 671                 strlist__add(entry->tevlist, command);
 672                 free(command);
 673         }
 674         list_add_tail(&entry->node, &pcache->entries);
 675         pr_debug("Added probe cache: %d\n", ntevs);
 676         return 0;
 677
 678 out_err:
 679         pr_debug("Failed to add probe caches\n");
 680         probe_cache_entry__delete(entry);
 681         return ret;
 682 }
 683
 684 #ifdef HAVE_GELF_GETNOTE_SUPPORT
 685 static unsigned long long sdt_note__get_addr(struct sdt_note *note)
 686 {
 687         return note->bit32 ? (unsigned long long)note->addr.a32[0]
 688                  : (unsigned long long)note->addr.a64[0];
 689 }
 690
 691 int probe_cache__scan_sdt(struct probe_cache *pcache, const char *pathname)
 692 {
 693         struct probe_cache_entry *entry = NULL;
 694         struct list_head sdtlist;
 695         struct sdt_note *note;
 696         char *buf;
 697         char sdtgrp[64];
 698         int ret;
 699
 700         INIT_LIST_HEAD(&sdtlist);
 701         ret = get_sdt_note_list(&sdtlist, pathname);
 702         if (ret < 0) {
 703                 pr_debug("Failed to get sdt note: %d\n", ret);
 704                 return ret;
 705         }
 706         list_for_each_entry(note, &sdtlist, note_list) {
 707                 ret = snprintf(sdtgrp, 64, "sdt_%s", note->provider);
 708                 if (ret < 0)
 709                         break;
 710                 /* Try to find same-name entry */
 711                 entry = probe_cache__find_by_name(pcache, sdtgrp, note->name);
 712                 if (!entry) {
 713                         entry = probe_cache_entry__new(NULL);
 714                         if (!entry) {
 715                                 ret = -ENOMEM;
 716                                 break;
 717                         }
 718                         entry->sdt = true;
 719                         ret = asprintf(&entry->spev, "%s:%s=%s", sdtgrp,
 720                                         note->name, note->name);
 721                         if (ret < 0)
 722                                 break;
 723                         entry->pev.event = strdup(note->name);
 724                         entry->pev.group = strdup(sdtgrp);
 725                         list_add_tail(&entry->node, &pcache->entries);
 726                 }
 727                 ret = asprintf(&buf, "p:%s/%s %s:0x%llx",
 728                                 sdtgrp, note->name, pathname,
 729                                 sdt_note__get_addr(note));
 730                 if (ret < 0)
 731                         break;
 732                 strlist__add(entry->tevlist, buf);
 733                 free(buf);
 734                 entry = NULL;
 735         }
 736         if (entry) {
 737                 list_del_init(&entry->node);
 738                 probe_cache_entry__delete(entry);
 739         }
 740         cleanup_sdt_note_list(&sdtlist);
 741         return ret;
 742 }
 743 #endif
 744
 745 static int probe_cache_entry__write(struct probe_cache_entry *entry, int fd)
 746 {
 747         struct str_node *snode;
 748         struct stat st;
 749         struct iovec iov[3];
 750         const char *prefix = entry->sdt ? "%" : "#";
 751         int ret;
 752         /* Save stat for rollback */
 753         ret = fstat(fd, &st);
 754         if (ret < 0)
 755                 return ret;
 756
 757         pr_debug("Writing cache: %s%s\n", prefix, entry->spev);
 758         iov[0].iov_base = (void *)prefix; iov[0].iov_len = 1;
 759         iov[1].iov_base = entry->spev; iov[1].iov_len = strlen(entry->spev);
 760         iov[2].iov_base = (void *)"\n"; iov[2].iov_len = 1;
 761         ret = writev(fd, iov, 3);
 762         if (ret < (int)iov[1].iov_len + 2)
 763                 goto rollback;
 764
 765         strlist__for_each_entry(snode, entry->tevlist) {
 766                 iov[0].iov_base = (void *)snode->s;
 767                 iov[0].iov_len = strlen(snode->s);
 768                 iov[1].iov_base = (void *)"\n"; iov[1].iov_len = 1;
 769                 ret = writev(fd, iov, 2);
 770                 if (ret < (int)iov[0].iov_len + 1)
 771                         goto rollback;
 772         }
 773         return 0;
 774
 775 rollback:
 776         /* Rollback to avoid cache file corruption */
 777         if (ret > 0)
 778                 ret = -1;
 779         if (ftruncate(fd, st.st_size) < 0)
 780                 ret = -2;
 781
 782         return ret;
 783 }
 784
 785 int probe_cache__commit(struct probe_cache *pcache)
 786 {
 787         struct probe_cache_entry *entry;
 788         int ret = 0;
 789
 790         /* TBD: if we do not update existing entries, skip it */
 791         ret = lseek(pcache->fd, 0, SEEK_SET);
 792         if (ret < 0)
 793                 goto out;
 794
 795         ret = ftruncate(pcache->fd, 0);
 796         if (ret < 0)
 797                 goto out;
 798
 799         for_each_probe_cache_entry(entry, pcache) {
 800                 ret = probe_cache_entry__write(entry, pcache->fd);
 801                 pr_debug("Cache committed: %d\n", ret);
 802                 if (ret < 0)
 803                         break;
 804         }
 805 out:
 806         return ret;
 807 }
 808
 809 static bool probe_cache_entry__compare(struct probe_cache_entry *entry,
 810                                        struct strfilter *filter)
 811 {
 812         char buf[128], *ptr = entry->spev;
 813
 814         if (entry->pev.event) {
 815                 snprintf(buf, 128, "%s:%s", entry->pev.group, entry->pev.event);
 816                 ptr = buf;
 817         }
 818         return strfilter__compare(filter, ptr);
 819 }
 820
 821 int probe_cache__filter_purge(struct probe_cache *pcache,
 822                               struct strfilter *filter)
 823 {
 824         struct probe_cache_entry *entry, *tmp;
 825
 826         list_for_each_entry_safe(entry, tmp, &pcache->entries, node) {
 827                 if (probe_cache_entry__compare(entry, filter)) {
 828                         pr_info("Removed cached event: %s\n", entry->spev);
 829                         list_del_init(&entry->node);
 830                         probe_cache_entry__delete(entry);
 831                 }
 832         }
 833         return 0;
 834 }
 835
 836 static int probe_cache__show_entries(struct probe_cache *pcache,
 837                                      struct strfilter *filter)
 838 {
 839         struct probe_cache_entry *entry;
 840
 841         for_each_probe_cache_entry(entry, pcache) {
 842                 if (probe_cache_entry__compare(entry, filter))
 843                         printf("%s\n", entry->spev);
 844         }
 845         return 0;
 846 }
 847
 848 /* Show all cached probes */
 849 int probe_cache__show_all_caches(struct strfilter *filter)
 850 {
 851         struct probe_cache *pcache;
 852         struct strlist *bidlist;
 853         struct str_node *nd;
 854         char *buf = strfilter__string(filter);
 855
 856         pr_debug("list cache with filter: %s\n", buf);
 857         free(buf);
 858
 859         bidlist = build_id_cache__list_all(true);
 860         if (!bidlist) {
 861                 pr_debug("Failed to get buildids: %d\n", errno);
 862                 return -EINVAL;
 863         }
 864         strlist__for_each_entry(nd, bidlist) {
 865                 pcache = probe_cache__new(nd->s);
 866                 if (!pcache)
 867                         continue;
 868                 if (!list_empty(&pcache->entries)) {
 869                         buf = build_id_cache__origname(nd->s);
 870                         printf("%s (%s):\n", buf, nd->s);
 871                         free(buf);
 872                         probe_cache__show_entries(pcache, filter);
 873                 }
 874                 probe_cache__delete(pcache);
 875         }
 876         strlist__delete(bidlist);
 877
 878         return 0;
 879 }