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                         ret = strlist__add(plist, ent->s);
 305                         if (ret == -ENOMEM) {
 306                                 pr_err("strlist__add failed with -ENOMEM\n");
 307                                 goto out;
 308                         }
 309                         ret = 0;
 310                 }
 311         }
 312 out:
 313         strlist__delete(namelist);
 314
 315         return ret;
 316 }
 317
 318 int probe_file__del_strlist(int fd, struct strlist *namelist)
 319 {
 320         int ret = 0;
 321         struct str_node *ent;
 322
 323         strlist__for_each_entry(ent, namelist) {
 324                 ret = __del_trace_probe_event(fd, ent);
 325                 if (ret < 0)
 326                         break;
 327         }
 328         return ret;
 329 }
 330
 331 int probe_file__del_events(int fd, struct strfilter *filter)
 332 {
 333         struct strlist *namelist;
 334         int ret;
 335
 336         namelist = strlist__new(NULL, NULL);
 337         if (!namelist)
 338                 return -ENOMEM;
 339
 340         ret = probe_file__get_events(fd, filter, namelist);
 341         if (ret < 0)
 342                 return ret;
 343
 344         ret = probe_file__del_strlist(fd, namelist);
 345         strlist__delete(namelist);
 346
 347         return ret;
 348 }
 349
 350 /* Caller must ensure to remove this entry from list */
 351 static void probe_cache_entry__delete(struct probe_cache_entry *entry)
 352 {
 353         if (entry) {
 354                 BUG_ON(!list_empty(&entry->node));
 355
 356                 strlist__delete(entry->tevlist);
 357                 clear_perf_probe_event(&entry->pev);
 358                 zfree(&entry->spev);
 359                 free(entry);
 360         }
 361 }
 362
 363 static struct probe_cache_entry *
 364 probe_cache_entry__new(struct perf_probe_event *pev)
 365 {
 366         struct probe_cache_entry *entry = zalloc(sizeof(*entry));
 367
 368         if (entry) {
 369                 INIT_LIST_HEAD(&entry->node);
 370                 entry->tevlist = strlist__new(NULL, NULL);
 371                 if (!entry->tevlist)
 372                         zfree(&entry);
 373                 else if (pev) {
 374                         entry->spev = synthesize_perf_probe_command(pev);
 375                         if (!entry->spev ||
 376                             perf_probe_event__copy(&entry->pev, pev) < 0) {
 377                                 probe_cache_entry__delete(entry);
 378                                 return NULL;
 379                         }
 380                 }
 381         }
 382
 383         return entry;
 384 }
 385
 386 int probe_cache_entry__get_event(struct probe_cache_entry *entry,
 387                                  struct probe_trace_event **tevs)
 388 {
 389         struct probe_trace_event *tev;
 390         struct str_node *node;
 391         int ret, i;
 392
 393         ret = strlist__nr_entries(entry->tevlist);
 394         if (ret > probe_conf.max_probes)
 395                 return -E2BIG;
 396
 397         *tevs = zalloc(ret * sizeof(*tev));
 398         if (!*tevs)
 399                 return -ENOMEM;
 400
 401         i = 0;
 402         strlist__for_each_entry(node, entry->tevlist) {
 403                 tev = &(*tevs)[i++];
 404                 ret = parse_probe_trace_command(node->s, tev);
 405                 if (ret < 0)
 406                         break;
 407         }
 408         return i;
 409 }
 410
 411 /* For the kernel probe caches, pass target = NULL or DSO__NAME_KALLSYMS */
 412 static int probe_cache__open(struct probe_cache *pcache, const char *target,
 413                              struct nsinfo *nsi)
 414 {
 415         char cpath[PATH_MAX];
 416         char sbuildid[SBUILD_ID_SIZE];
 417         char *dir_name = NULL;
 418         bool is_kallsyms = false;
 419         int ret, fd;
 420         struct nscookie nsc;
 421
 422         if (target && build_id_cache__cached(target)) {
 423                 /* This is a cached buildid */
 424                 strlcpy(sbuildid, target, SBUILD_ID_SIZE);
 425                 dir_name = build_id_cache__linkname(sbuildid, NULL, 0);
 426                 goto found;
 427         }
 428
 429         if (!target || !strcmp(target, DSO__NAME_KALLSYMS)) {
 430                 target = DSO__NAME_KALLSYMS;
 431                 is_kallsyms = true;
 432                 ret = sysfs__sprintf_build_id("/", sbuildid);
 433         } else {
 434                 nsinfo__mountns_enter(nsi, &nsc);
 435                 ret = filename__sprintf_build_id(target, sbuildid);
 436                 nsinfo__mountns_exit(&nsc);
 437         }
 438
 439         if (ret < 0) {
 440                 pr_debug("Failed to get build-id from %s.\n", target);
 441                 return ret;
 442         }
 443
 444         /* If we have no buildid cache, make it */
 445         if (!build_id_cache__cached(sbuildid)) {
 446                 ret = build_id_cache__add_s(sbuildid, target, nsi,
 447                                             is_kallsyms, NULL);
 448                 if (ret < 0) {
 449                         pr_debug("Failed to add build-id cache: %s\n", target);
 450                         return ret;
 451                 }
 452         }
 453
 454         dir_name = build_id_cache__cachedir(sbuildid, target, nsi, is_kallsyms,
 455                                             false);
 456 found:
 457         if (!dir_name) {
 458                 pr_debug("Failed to get cache from %s\n", target);
 459                 return -ENOMEM;
 460         }
 461
 462         snprintf(cpath, PATH_MAX, "%s/probes", dir_name);
 463         fd = open(cpath, O_CREAT | O_RDWR, 0644);
 464         if (fd < 0)
 465                 pr_debug("Failed to open cache(%d): %s\n", fd, cpath);
 466         free(dir_name);
 467         pcache->fd = fd;
 468
 469         return fd;
 470 }
 471
 472 static int probe_cache__load(struct probe_cache *pcache)
 473 {
 474         struct probe_cache_entry *entry = NULL;
 475         char buf[MAX_CMDLEN], *p;
 476         int ret = 0, fddup;
 477         FILE *fp;
 478
 479         fddup = dup(pcache->fd);
 480         if (fddup < 0)
 481                 return -errno;
 482         fp = fdopen(fddup, "r");
 483         if (!fp) {
 484                 close(fddup);
 485                 return -EINVAL;
 486         }
 487
 488         while (!feof(fp)) {
 489                 if (!fgets(buf, MAX_CMDLEN, fp))
 490                         break;
 491                 p = strchr(buf, '\n');
 492                 if (p)
 493                         *p = '\0';
 494                 /* #perf_probe_event or %sdt_event */
 495                 if (buf[0] == '#' || buf[0] == '%') {
 496                         entry = probe_cache_entry__new(NULL);
 497                         if (!entry) {
 498                                 ret = -ENOMEM;
 499                                 goto out;
 500                         }
 501                         if (buf[0] == '%')
 502                                 entry->sdt = true;
 503                         entry->spev = strdup(buf + 1);
 504                         if (entry->spev)
 505                                 ret = parse_perf_probe_command(buf + 1,
 506                                                                 &entry->pev);
 507                         else
 508                                 ret = -ENOMEM;
 509                         if (ret < 0) {
 510                                 probe_cache_entry__delete(entry);
 511                                 goto out;
 512                         }
 513                         list_add_tail(&entry->node, &pcache->entries);
 514                 } else {        /* trace_probe_event */
 515                         if (!entry) {
 516                                 ret = -EINVAL;
 517                                 goto out;
 518                         }
 519                         ret = strlist__add(entry->tevlist, buf);
 520                         if (ret == -ENOMEM) {
 521                                 pr_err("strlist__add failed with -ENOMEM\n");
 522                                 goto out;
 523                         }
 524                 }
 525         }
 526 out:
 527         fclose(fp);
 528         return ret;
 529 }
 530
 531 static struct probe_cache *probe_cache__alloc(void)
 532 {
 533         struct probe_cache *pcache = zalloc(sizeof(*pcache));
 534
 535         if (pcache) {
 536                 INIT_LIST_HEAD(&pcache->entries);
 537                 pcache->fd = -EINVAL;
 538         }
 539         return pcache;
 540 }
 541
 542 void probe_cache__purge(struct probe_cache *pcache)
 543 {
 544         struct probe_cache_entry *entry, *n;
 545
 546         list_for_each_entry_safe(entry, n, &pcache->entries, node) {
 547                 list_del_init(&entry->node);
 548                 probe_cache_entry__delete(entry);
 549         }
 550 }
 551
 552 void probe_cache__delete(struct probe_cache *pcache)
 553 {
 554         if (!pcache)
 555                 return;
 556
 557         probe_cache__purge(pcache);
 558         if (pcache->fd > 0)
 559                 close(pcache->fd);
 560         free(pcache);
 561 }
 562
 563 struct probe_cache *probe_cache__new(const char *target, struct nsinfo *nsi)
 564 {
 565         struct probe_cache *pcache = probe_cache__alloc();
 566         int ret;
 567
 568         if (!pcache)
 569                 return NULL;
 570
 571         ret = probe_cache__open(pcache, target, nsi);
 572         if (ret < 0) {
 573                 pr_debug("Cache open error: %d\n", ret);
 574                 goto out_err;
 575         }
 576
 577         ret = probe_cache__load(pcache);
 578         if (ret < 0) {
 579                 pr_debug("Cache read error: %d\n", ret);
 580                 goto out_err;
 581         }
 582
 583         return pcache;
 584
 585 out_err:
 586         probe_cache__delete(pcache);
 587         return NULL;
 588 }
 589
 590 static bool streql(const char *a, const char *b)
 591 {
 592         if (a == b)
 593                 return true;
 594
 595         if (!a || !b)
 596                 return false;
 597
 598         return !strcmp(a, b);
 599 }
 600
 601 struct probe_cache_entry *
 602 probe_cache__find(struct probe_cache *pcache, struct perf_probe_event *pev)
 603 {
 604         struct probe_cache_entry *entry = NULL;
 605         char *cmd = synthesize_perf_probe_command(pev);
 606
 607         if (!cmd)
 608                 return NULL;
 609
 610         for_each_probe_cache_entry(entry, pcache) {
 611                 if (pev->sdt) {
 612                         if (entry->pev.event &&
 613                             streql(entry->pev.event, pev->event) &&
 614                             (!pev->group ||
 615                              streql(entry->pev.group, pev->group)))
 616                                 goto found;
 617
 618                         continue;
 619                 }
 620                 /* Hit if same event name or same command-string */
 621                 if ((pev->event &&
 622                      (streql(entry->pev.group, pev->group) &&
 623                       streql(entry->pev.event, pev->event))) ||
 624                     (!strcmp(entry->spev, cmd)))
 625                         goto found;
 626         }
 627         entry = NULL;
 628
 629 found:
 630         free(cmd);
 631         return entry;
 632 }
 633
 634 struct probe_cache_entry *
 635 probe_cache__find_by_name(struct probe_cache *pcache,
 636                           const char *group, const char *event)
 637 {
 638         struct probe_cache_entry *entry = NULL;
 639
 640         for_each_probe_cache_entry(entry, pcache) {
 641                 /* Hit if same event name or same command-string */
 642                 if (streql(entry->pev.group, group) &&
 643                     streql(entry->pev.event, event))
 644                         goto found;
 645         }
 646         entry = NULL;
 647
 648 found:
 649         return entry;
 650 }
 651
 652 int probe_cache__add_entry(struct probe_cache *pcache,
 653                            struct perf_probe_event *pev,
 654                            struct probe_trace_event *tevs, int ntevs)
 655 {
 656         struct probe_cache_entry *entry = NULL;
 657         char *command;
 658         int i, ret = 0;
 659
 660         if (!pcache || !pev || !tevs || ntevs <= 0) {
 661                 ret = -EINVAL;
 662                 goto out_err;
 663         }
 664
 665         /* Remove old cache entry */
 666         entry = probe_cache__find(pcache, pev);
 667         if (entry) {
 668                 list_del_init(&entry->node);
 669                 probe_cache_entry__delete(entry);
 670         }
 671
 672         ret = -ENOMEM;
 673         entry = probe_cache_entry__new(pev);
 674         if (!entry)
 675                 goto out_err;
 676
 677         for (i = 0; i < ntevs; i++) {
 678                 if (!tevs[i].point.symbol)
 679                         continue;
 680
 681                 command = synthesize_probe_trace_command(&tevs[i]);
 682                 if (!command)
 683                         goto out_err;
 684                 ret = strlist__add(entry->tevlist, command);
 685                 if (ret == -ENOMEM) {
 686                         pr_err("strlist__add failed with -ENOMEM\n");
 687                         goto out_err;
 688                 }
 689
 690                 free(command);
 691         }
 692         list_add_tail(&entry->node, &pcache->entries);
 693         pr_debug("Added probe cache: %d\n", ntevs);
 694         return 0;
 695
 696 out_err:
 697         pr_debug("Failed to add probe caches\n");
 698         probe_cache_entry__delete(entry);
 699         return ret;
 700 }
 701
 702 #ifdef HAVE_GELF_GETNOTE_SUPPORT
 703 static unsigned long long sdt_note__get_addr(struct sdt_note *note)
 704 {
 705         return note->bit32 ?
 706                 (unsigned long long)note->addr.a32[SDT_NOTE_IDX_LOC] :
 707                 (unsigned long long)note->addr.a64[SDT_NOTE_IDX_LOC];
 708 }
 709
 710 static unsigned long long sdt_note__get_ref_ctr_offset(struct sdt_note *note)
 711 {
 712         return note->bit32 ?
 713                 (unsigned long long)note->addr.a32[SDT_NOTE_IDX_REFCTR] :
 714                 (unsigned long long)note->addr.a64[SDT_NOTE_IDX_REFCTR];
 715 }
 716
 717 static const char * const type_to_suffix[] = {
 718         ":s64", "", "", "", ":s32", "", ":s16", ":s8",
 719         "", ":u8", ":u16", "", ":u32", "", "", "", ":u64"
 720 };
 721
 722 /*
 723  * Isolate the string number and convert it into a decimal value;
 724  * this will be an index to get suffix of the uprobe name (defining
 725  * the type)
 726  */
 727 static int sdt_arg_parse_size(char *n_ptr, const char **suffix)
 728 {
 729         long type_idx;
 730
 731         type_idx = strtol(n_ptr, NULL, 10);
 732         if (type_idx < -8 || type_idx > 8) {
 733                 pr_debug4("Failed to get a valid sdt type\n");
 734                 return -1;
 735         }
 736
 737         *suffix = type_to_suffix[type_idx + 8];
 738         return 0;
 739 }
 740
 741 static int synthesize_sdt_probe_arg(struct strbuf *buf, int i, const char *arg)
 742 {
 743         char *op, *desc = strdup(arg), *new_op = NULL;
 744         const char *suffix = "";
 745         int ret = -1;
 746
 747         if (desc == NULL) {
 748                 pr_debug4("Allocation error\n");
 749                 return ret;
 750         }
 751
 752         /*
 753          * Argument is in N@OP format. N is size of the argument and OP is
 754          * the actual assembly operand. N can be omitted; in that case
 755          * argument is just OP(without @).
 756          */
 757         op = strchr(desc, '@');
 758         if (op) {
 759                 op[0] = '\0';
 760                 op++;
 761
 762                 if (sdt_arg_parse_size(desc, &suffix))
 763                         goto error;
 764         } else {
 765                 op = desc;
 766         }
 767
 768         ret = arch_sdt_arg_parse_op(op, &new_op);
 769
 770         if (ret < 0)
 771                 goto error;
 772
 773         if (ret == SDT_ARG_VALID) {
 774                 ret = strbuf_addf(buf, " arg%d=%s%s", i + 1, new_op, suffix);
 775                 if (ret < 0)
 776                         goto error;
 777         }
 778
 779         ret = 0;
 780 error:
 781         free(desc);
 782         free(new_op);
 783         return ret;
 784 }
 785
 786 static char *synthesize_sdt_probe_command(struct sdt_note *note,
 787                                         const char *pathname,
 788                                         const char *sdtgrp)
 789 {
 790         struct strbuf buf;
 791         char *ret = NULL, **args;
 792         int i, args_count, err;
 793         unsigned long long ref_ctr_offset;
 794
 795         if (strbuf_init(&buf, 32) < 0)
 796                 return NULL;
 797
 798         err = strbuf_addf(&buf, "p:%s/%s %s:0x%llx",
 799                         sdtgrp, note->name, pathname,
 800                         sdt_note__get_addr(note));
 801
 802         ref_ctr_offset = sdt_note__get_ref_ctr_offset(note);
 803         if (ref_ctr_offset && err >= 0)
 804                 err = strbuf_addf(&buf, "(0x%llx)", ref_ctr_offset);
 805
 806         if (err < 0)
 807                 goto error;
 808
 809         if (!note->args)
 810                 goto out;
 811
 812         if (note->args) {
 813                 args = argv_split(note->args, &args_count);
 814
 815                 for (i = 0; i < args_count; ++i) {
 816                         if (synthesize_sdt_probe_arg(&buf, i, args[i]) < 0)
 817                                 goto error;
 818                 }
 819         }
 820
 821 out:
 822         ret = strbuf_detach(&buf, NULL);
 823 error:
 824         strbuf_release(&buf);
 825         return ret;
 826 }
 827
 828 int probe_cache__scan_sdt(struct probe_cache *pcache, const char *pathname)
 829 {
 830         struct probe_cache_entry *entry = NULL;
 831         struct list_head sdtlist;
 832         struct sdt_note *note;
 833         char *buf;
 834         char sdtgrp[64];
 835         int ret;
 836
 837         INIT_LIST_HEAD(&sdtlist);
 838         ret = get_sdt_note_list(&sdtlist, pathname);
 839         if (ret < 0) {
 840                 pr_debug4("Failed to get sdt note: %d\n", ret);
 841                 return ret;
 842         }
 843         list_for_each_entry(note, &sdtlist, note_list) {
 844                 ret = snprintf(sdtgrp, 64, "sdt_%s", note->provider);
 845                 if (ret < 0)
 846                         break;
 847                 /* Try to find same-name entry */
 848                 entry = probe_cache__find_by_name(pcache, sdtgrp, note->name);
 849                 if (!entry) {
 850                         entry = probe_cache_entry__new(NULL);
 851                         if (!entry) {
 852                                 ret = -ENOMEM;
 853                                 break;
 854                         }
 855                         entry->sdt = true;
 856                         ret = asprintf(&entry->spev, "%s:%s=%s", sdtgrp,
 857                                         note->name, note->name);
 858                         if (ret < 0)
 859                                 break;
 860                         entry->pev.event = strdup(note->name);
 861                         entry->pev.group = strdup(sdtgrp);
 862                         list_add_tail(&entry->node, &pcache->entries);
 863                 }
 864                 buf = synthesize_sdt_probe_command(note, pathname, sdtgrp);
 865                 if (!buf) {
 866                         ret = -ENOMEM;
 867                         break;
 868                 }
 869
 870                 ret = strlist__add(entry->tevlist, buf);
 871
 872                 free(buf);
 873                 entry = NULL;
 874
 875                 if (ret == -ENOMEM) {
 876                         pr_err("strlist__add failed with -ENOMEM\n");
 877                         break;
 878                 }
 879         }
 880         if (entry) {
 881                 list_del_init(&entry->node);
 882                 probe_cache_entry__delete(entry);
 883         }
 884         cleanup_sdt_note_list(&sdtlist);
 885         return ret;
 886 }
 887 #endif
 888
 889 static int probe_cache_entry__write(struct probe_cache_entry *entry, int fd)
 890 {
 891         struct str_node *snode;
 892         struct stat st;
 893         struct iovec iov[3];
 894         const char *prefix = entry->sdt ? "%" : "#";
 895         int ret;
 896         /* Save stat for rollback */
 897         ret = fstat(fd, &st);
 898         if (ret < 0)
 899                 return ret;
 900
 901         pr_debug("Writing cache: %s%s\n", prefix, entry->spev);
 902         iov[0].iov_base = (void *)prefix; iov[0].iov_len = 1;
 903         iov[1].iov_base = entry->spev; iov[1].iov_len = strlen(entry->spev);
 904         iov[2].iov_base = (void *)"\n"; iov[2].iov_len = 1;
 905         ret = writev(fd, iov, 3);
 906         if (ret < (int)iov[1].iov_len + 2)
 907                 goto rollback;
 908
 909         strlist__for_each_entry(snode, entry->tevlist) {
 910                 iov[0].iov_base = (void *)snode->s;
 911                 iov[0].iov_len = strlen(snode->s);
 912                 iov[1].iov_base = (void *)"\n"; iov[1].iov_len = 1;
 913                 ret = writev(fd, iov, 2);
 914                 if (ret < (int)iov[0].iov_len + 1)
 915                         goto rollback;
 916         }
 917         return 0;
 918
 919 rollback:
 920         /* Rollback to avoid cache file corruption */
 921         if (ret > 0)
 922                 ret = -1;
 923         if (ftruncate(fd, st.st_size) < 0)
 924                 ret = -2;
 925
 926         return ret;
 927 }
 928
 929 int probe_cache__commit(struct probe_cache *pcache)
 930 {
 931         struct probe_cache_entry *entry;
 932         int ret = 0;
 933
 934         /* TBD: if we do not update existing entries, skip it */
 935         ret = lseek(pcache->fd, 0, SEEK_SET);
 936         if (ret < 0)
 937                 goto out;
 938
 939         ret = ftruncate(pcache->fd, 0);
 940         if (ret < 0)
 941                 goto out;
 942
 943         for_each_probe_cache_entry(entry, pcache) {
 944                 ret = probe_cache_entry__write(entry, pcache->fd);
 945                 pr_debug("Cache committed: %d\n", ret);
 946                 if (ret < 0)
 947                         break;
 948         }
 949 out:
 950         return ret;
 951 }
 952
 953 static bool probe_cache_entry__compare(struct probe_cache_entry *entry,
 954                                        struct strfilter *filter)
 955 {
 956         char buf[128], *ptr = entry->spev;
 957
 958         if (entry->pev.event) {
 959                 snprintf(buf, 128, "%s:%s", entry->pev.group, entry->pev.event);
 960                 ptr = buf;
 961         }
 962         return strfilter__compare(filter, ptr);
 963 }
 964
 965 int probe_cache__filter_purge(struct probe_cache *pcache,
 966                               struct strfilter *filter)
 967 {
 968         struct probe_cache_entry *entry, *tmp;
 969
 970         list_for_each_entry_safe(entry, tmp, &pcache->entries, node) {
 971                 if (probe_cache_entry__compare(entry, filter)) {
 972                         pr_info("Removed cached event: %s\n", entry->spev);
 973                         list_del_init(&entry->node);
 974                         probe_cache_entry__delete(entry);
 975                 }
 976         }
 977         return 0;
 978 }
 979
 980 static int probe_cache__show_entries(struct probe_cache *pcache,
 981                                      struct strfilter *filter)
 982 {
 983         struct probe_cache_entry *entry;
 984
 985         for_each_probe_cache_entry(entry, pcache) {
 986                 if (probe_cache_entry__compare(entry, filter))
 987                         printf("%s\n", entry->spev);
 988         }
 989         return 0;
 990 }
 991
 992 /* Show all cached probes */
 993 int probe_cache__show_all_caches(struct strfilter *filter)
 994 {
 995         struct probe_cache *pcache;
 996         struct strlist *bidlist;
 997         struct str_node *nd;
 998         char *buf = strfilter__string(filter);
 999
1000         pr_debug("list cache with filter: %s\n", buf);
1001         free(buf);
1002
1003         bidlist = build_id_cache__list_all(true);
1004         if (!bidlist) {
1005                 pr_debug("Failed to get buildids: %d\n", errno);
1006                 return -EINVAL;
1007         }
1008         strlist__for_each_entry(nd, bidlist) {
1009                 pcache = probe_cache__new(nd->s, NULL);
1010                 if (!pcache)
1011                         continue;
1012                 if (!list_empty(&pcache->entries)) {
1013                         buf = build_id_cache__origname(nd->s);
1014                         printf("%s (%s):\n", buf, nd->s);
1015                         free(buf);
1016                         probe_cache__show_entries(pcache, filter);
1017                 }
1018                 probe_cache__delete(pcache);
1019         }
1020         strlist__delete(bidlist);
1021
1022         return 0;
1023 }
1024
1025 enum ftrace_readme {
1026         FTRACE_README_PROBE_TYPE_X = 0,
1027         FTRACE_README_KRETPROBE_OFFSET,
1028         FTRACE_README_UPROBE_REF_CTR,
1029         FTRACE_README_USER_ACCESS,
1030         FTRACE_README_MULTIPROBE_EVENT,
1031         FTRACE_README_IMMEDIATE_VALUE,
1032         FTRACE_README_END,
1033 };
1034
1035 static struct {
1036         const char *pattern;
1037         bool avail;
1038 } ftrace_readme_table[] = {
1039 #define DEFINE_TYPE(idx, pat)                   \
1040         [idx] = {.pattern = pat, .avail = false}
1041         DEFINE_TYPE(FTRACE_README_PROBE_TYPE_X, "*type: * x8/16/32/64,*"),
1042         DEFINE_TYPE(FTRACE_README_KRETPROBE_OFFSET, "*place (kretprobe): *"),
1043         DEFINE_TYPE(FTRACE_README_UPROBE_REF_CTR, "*ref_ctr_offset*"),
1044         DEFINE_TYPE(FTRACE_README_USER_ACCESS, "*[u]<offset>*"),
1045         DEFINE_TYPE(FTRACE_README_MULTIPROBE_EVENT, "*Create/append/*"),
1046         DEFINE_TYPE(FTRACE_README_IMMEDIATE_VALUE, "*\\imm-value,*"),
1047 };
1048
1049 static bool scan_ftrace_readme(enum ftrace_readme type)
1050 {
1051         int fd;
1052         FILE *fp;
1053         char *buf = NULL;
1054         size_t len = 0;
1055         bool ret = false;
1056         static bool scanned = false;
1057
1058         if (scanned)
1059                 goto result;
1060
1061         fd = open_trace_file("README", false);
1062         if (fd < 0)
1063                 return ret;
1064
1065         fp = fdopen(fd, "r");
1066         if (!fp) {
1067                 close(fd);
1068                 return ret;
1069         }
1070
1071         while (getline(&buf, &len, fp) > 0)
1072                 for (enum ftrace_readme i = 0; i < FTRACE_README_END; i++)
1073                         if (!ftrace_readme_table[i].avail)
1074                                 ftrace_readme_table[i].avail =
1075                                         strglobmatch(buf, ftrace_readme_table[i].pattern);
1076         scanned = true;
1077
1078         fclose(fp);
1079         free(buf);
1080
1081 result:
1082         if (type >= FTRACE_README_END)
1083                 return false;
1084
1085         return ftrace_readme_table[type].avail;
1086 }
1087
1088 bool probe_type_is_available(enum probe_type type)
1089 {
1090         if (type >= PROBE_TYPE_END)
1091                 return false;
1092         else if (type == PROBE_TYPE_X)
1093                 return scan_ftrace_readme(FTRACE_README_PROBE_TYPE_X);
1094
1095         return true;
1096 }
1097
1098 bool kretprobe_offset_is_supported(void)
1099 {
1100         return scan_ftrace_readme(FTRACE_README_KRETPROBE_OFFSET);
1101 }
1102
1103 bool uprobe_ref_ctr_is_supported(void)
1104 {
1105         return scan_ftrace_readme(FTRACE_README_UPROBE_REF_CTR);
1106 }
1107
1108 bool user_access_is_supported(void)
1109 {
1110         return scan_ftrace_readme(FTRACE_README_USER_ACCESS);
1111 }
1112
1113 bool multiprobe_event_is_supported(void)
1114 {
1115         return scan_ftrace_readme(FTRACE_README_MULTIPROBE_EVENT);
1116 }
1117
1118 bool immediate_value_is_supported(void)
1119 {
1120         return scan_ftrace_readme(FTRACE_README_IMMEDIATE_VALUE);
1121 }