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                 /* Skip if there is same name multi-probe event in the list */
 210                 if (ret == -EEXIST)
 211                         ret = 0;
 212                 if (ret < 0)
 213                         break;
 214         }
 215         strlist__delete(rawlist);
 216
 217         if (ret < 0) {
 218                 strlist__delete(sl);
 219                 return NULL;
 220         }
 221         return sl;
 222 }
 223
 224 /* Get current perf-probe event names */
 225 struct strlist *probe_file__get_namelist(int fd)
 226 {
 227         return __probe_file__get_namelist(fd, false);
 228 }
 229
 230 int probe_file__add_event(int fd, struct probe_trace_event *tev)
 231 {
 232         int ret = 0;
 233         char *buf = synthesize_probe_trace_command(tev);
 234         char sbuf[STRERR_BUFSIZE];
 235
 236         if (!buf) {
 237                 pr_debug("Failed to synthesize probe trace event.\n");
 238                 return -EINVAL;
 239         }
 240
 241         pr_debug("Writing event: %s\n", buf);
 242         if (!probe_event_dry_run) {
 243                 if (write(fd, buf, strlen(buf)) < (int)strlen(buf)) {
 244                         ret = -errno;
 245                         pr_warning("Failed to write event: %s\n",
 246                                    str_error_r(errno, sbuf, sizeof(sbuf)));
 247                 }
 248         }
 249         free(buf);
 250
 251         return ret;
 252 }
 253
 254 static int __del_trace_probe_event(int fd, struct str_node *ent)
 255 {
 256         char *p;
 257         char buf[128];
 258         int ret;
 259
 260         /* Convert from perf-probe event to trace-probe event */
 261         ret = e_snprintf(buf, 128, "-:%s", ent->s);
 262         if (ret < 0)
 263                 goto error;
 264
 265         p = strchr(buf + 2, ':');
 266         if (!p) {
 267                 pr_debug("Internal error: %s should have ':' but not.\n",
 268                          ent->s);
 269                 ret = -ENOTSUP;
 270                 goto error;
 271         }
 272         *p = '/';
 273
 274         pr_debug("Writing event: %s\n", buf);
 275         ret = write(fd, buf, strlen(buf));
 276         if (ret < 0) {
 277                 ret = -errno;
 278                 goto error;
 279         }
 280
 281         return 0;
 282 error:
 283         pr_warning("Failed to delete event: %s\n",
 284                    str_error_r(-ret, buf, sizeof(buf)));
 285         return ret;
 286 }
 287
 288 int probe_file__get_events(int fd, struct strfilter *filter,
 289                            struct strlist *plist)
 290 {
 291         struct strlist *namelist;
 292         struct str_node *ent;
 293         const char *p;
 294         int ret = -ENOENT;
 295
 296         if (!plist)
 297                 return -EINVAL;
 298
 299         namelist = __probe_file__get_namelist(fd, true);
 300         if (!namelist)
 301                 return -ENOENT;
 302
 303         strlist__for_each_entry(ent, namelist) {
 304                 p = strchr(ent->s, ':');
 305                 if ((p && strfilter__compare(filter, p + 1)) ||
 306                     strfilter__compare(filter, ent->s)) {
 307                         ret = strlist__add(plist, ent->s);
 308                         if (ret == -ENOMEM) {
 309                                 pr_err("strlist__add failed with -ENOMEM\n");
 310                                 goto out;
 311                         }
 312                         ret = 0;
 313                 }
 314         }
 315 out:
 316         strlist__delete(namelist);
 317
 318         return ret;
 319 }
 320
 321 int probe_file__del_strlist(int fd, struct strlist *namelist)
 322 {
 323         int ret = 0;
 324         struct str_node *ent;
 325
 326         strlist__for_each_entry(ent, namelist) {
 327                 ret = __del_trace_probe_event(fd, ent);
 328                 if (ret < 0)
 329                         break;
 330         }
 331         return ret;
 332 }
 333
 334 int probe_file__del_events(int fd, struct strfilter *filter)
 335 {
 336         struct strlist *namelist;
 337         int ret;
 338
 339         namelist = strlist__new(NULL, NULL);
 340         if (!namelist)
 341                 return -ENOMEM;
 342
 343         ret = probe_file__get_events(fd, filter, namelist);
 344         if (ret < 0)
 345                 return ret;
 346
 347         ret = probe_file__del_strlist(fd, namelist);
 348         strlist__delete(namelist);
 349
 350         return ret;
 351 }
 352
 353 /* Caller must ensure to remove this entry from list */
 354 static void probe_cache_entry__delete(struct probe_cache_entry *entry)
 355 {
 356         if (entry) {
 357                 BUG_ON(!list_empty(&entry->node));
 358
 359                 strlist__delete(entry->tevlist);
 360                 clear_perf_probe_event(&entry->pev);
 361                 zfree(&entry->spev);
 362                 free(entry);
 363         }
 364 }
 365
 366 static struct probe_cache_entry *
 367 probe_cache_entry__new(struct perf_probe_event *pev)
 368 {
 369         struct probe_cache_entry *entry = zalloc(sizeof(*entry));
 370
 371         if (entry) {
 372                 INIT_LIST_HEAD(&entry->node);
 373                 entry->tevlist = strlist__new(NULL, NULL);
 374                 if (!entry->tevlist)
 375                         zfree(&entry);
 376                 else if (pev) {
 377                         entry->spev = synthesize_perf_probe_command(pev);
 378                         if (!entry->spev ||
 379                             perf_probe_event__copy(&entry->pev, pev) < 0) {
 380                                 probe_cache_entry__delete(entry);
 381                                 return NULL;
 382                         }
 383                 }
 384         }
 385
 386         return entry;
 387 }
 388
 389 int probe_cache_entry__get_event(struct probe_cache_entry *entry,
 390                                  struct probe_trace_event **tevs)
 391 {
 392         struct probe_trace_event *tev;
 393         struct str_node *node;
 394         int ret, i;
 395
 396         ret = strlist__nr_entries(entry->tevlist);
 397         if (ret > probe_conf.max_probes)
 398                 return -E2BIG;
 399
 400         *tevs = zalloc(ret * sizeof(*tev));
 401         if (!*tevs)
 402                 return -ENOMEM;
 403
 404         i = 0;
 405         strlist__for_each_entry(node, entry->tevlist) {
 406                 tev = &(*tevs)[i++];
 407                 ret = parse_probe_trace_command(node->s, tev);
 408                 if (ret < 0)
 409                         break;
 410         }
 411         return i;
 412 }
 413
 414 /* For the kernel probe caches, pass target = NULL or DSO__NAME_KALLSYMS */
 415 static int probe_cache__open(struct probe_cache *pcache, const char *target,
 416                              struct nsinfo *nsi)
 417 {
 418         char cpath[PATH_MAX];
 419         char sbuildid[SBUILD_ID_SIZE];
 420         char *dir_name = NULL;
 421         bool is_kallsyms = false;
 422         int ret, fd;
 423         struct nscookie nsc;
 424
 425         if (target && build_id_cache__cached(target)) {
 426                 /* This is a cached buildid */
 427                 strlcpy(sbuildid, target, SBUILD_ID_SIZE);
 428                 dir_name = build_id_cache__linkname(sbuildid, NULL, 0);
 429                 goto found;
 430         }
 431
 432         if (!target || !strcmp(target, DSO__NAME_KALLSYMS)) {
 433                 target = DSO__NAME_KALLSYMS;
 434                 is_kallsyms = true;
 435                 ret = sysfs__sprintf_build_id("/", sbuildid);
 436         } else {
 437                 nsinfo__mountns_enter(nsi, &nsc);
 438                 ret = filename__sprintf_build_id(target, sbuildid);
 439                 nsinfo__mountns_exit(&nsc);
 440         }
 441
 442         if (ret < 0) {
 443                 pr_debug("Failed to get build-id from %s.\n", target);
 444                 return ret;
 445         }
 446
 447         /* If we have no buildid cache, make it */
 448         if (!build_id_cache__cached(sbuildid)) {
 449                 ret = build_id_cache__add_s(sbuildid, target, nsi,
 450                                             is_kallsyms, NULL);
 451                 if (ret < 0) {
 452                         pr_debug("Failed to add build-id cache: %s\n", target);
 453                         return ret;
 454                 }
 455         }
 456
 457         dir_name = build_id_cache__cachedir(sbuildid, target, nsi, is_kallsyms,
 458                                             false);
 459 found:
 460         if (!dir_name) {
 461                 pr_debug("Failed to get cache from %s\n", target);
 462                 return -ENOMEM;
 463         }
 464
 465         snprintf(cpath, PATH_MAX, "%s/probes", dir_name);
 466         fd = open(cpath, O_CREAT | O_RDWR, 0644);
 467         if (fd < 0)
 468                 pr_debug("Failed to open cache(%d): %s\n", fd, cpath);
 469         free(dir_name);
 470         pcache->fd = fd;
 471
 472         return fd;
 473 }
 474
 475 static int probe_cache__load(struct probe_cache *pcache)
 476 {
 477         struct probe_cache_entry *entry = NULL;
 478         char buf[MAX_CMDLEN], *p;
 479         int ret = 0, fddup;
 480         FILE *fp;
 481
 482         fddup = dup(pcache->fd);
 483         if (fddup < 0)
 484                 return -errno;
 485         fp = fdopen(fddup, "r");
 486         if (!fp) {
 487                 close(fddup);
 488                 return -EINVAL;
 489         }
 490
 491         while (!feof(fp)) {
 492                 if (!fgets(buf, MAX_CMDLEN, fp))
 493                         break;
 494                 p = strchr(buf, '\n');
 495                 if (p)
 496                         *p = '\0';
 497                 /* #perf_probe_event or %sdt_event */
 498                 if (buf[0] == '#' || buf[0] == '%') {
 499                         entry = probe_cache_entry__new(NULL);
 500                         if (!entry) {
 501                                 ret = -ENOMEM;
 502                                 goto out;
 503                         }
 504                         if (buf[0] == '%')
 505                                 entry->sdt = true;
 506                         entry->spev = strdup(buf + 1);
 507                         if (entry->spev)
 508                                 ret = parse_perf_probe_command(buf + 1,
 509                                                                 &entry->pev);
 510                         else
 511                                 ret = -ENOMEM;
 512                         if (ret < 0) {
 513                                 probe_cache_entry__delete(entry);
 514                                 goto out;
 515                         }
 516                         list_add_tail(&entry->node, &pcache->entries);
 517                 } else {        /* trace_probe_event */
 518                         if (!entry) {
 519                                 ret = -EINVAL;
 520                                 goto out;
 521                         }
 522                         ret = strlist__add(entry->tevlist, buf);
 523                         if (ret == -ENOMEM) {
 524                                 pr_err("strlist__add failed with -ENOMEM\n");
 525                                 goto out;
 526                         }
 527                 }
 528         }
 529 out:
 530         fclose(fp);
 531         return ret;
 532 }
 533
 534 static struct probe_cache *probe_cache__alloc(void)
 535 {
 536         struct probe_cache *pcache = zalloc(sizeof(*pcache));
 537
 538         if (pcache) {
 539                 INIT_LIST_HEAD(&pcache->entries);
 540                 pcache->fd = -EINVAL;
 541         }
 542         return pcache;
 543 }
 544
 545 void probe_cache__purge(struct probe_cache *pcache)
 546 {
 547         struct probe_cache_entry *entry, *n;
 548
 549         list_for_each_entry_safe(entry, n, &pcache->entries, node) {
 550                 list_del_init(&entry->node);
 551                 probe_cache_entry__delete(entry);
 552         }
 553 }
 554
 555 void probe_cache__delete(struct probe_cache *pcache)
 556 {
 557         if (!pcache)
 558                 return;
 559
 560         probe_cache__purge(pcache);
 561         if (pcache->fd > 0)
 562                 close(pcache->fd);
 563         free(pcache);
 564 }
 565
 566 struct probe_cache *probe_cache__new(const char *target, struct nsinfo *nsi)
 567 {
 568         struct probe_cache *pcache = probe_cache__alloc();
 569         int ret;
 570
 571         if (!pcache)
 572                 return NULL;
 573
 574         ret = probe_cache__open(pcache, target, nsi);
 575         if (ret < 0) {
 576                 pr_debug("Cache open error: %d\n", ret);
 577                 goto out_err;
 578         }
 579
 580         ret = probe_cache__load(pcache);
 581         if (ret < 0) {
 582                 pr_debug("Cache read error: %d\n", ret);
 583                 goto out_err;
 584         }
 585
 586         return pcache;
 587
 588 out_err:
 589         probe_cache__delete(pcache);
 590         return NULL;
 591 }
 592
 593 static bool streql(const char *a, const char *b)
 594 {
 595         if (a == b)
 596                 return true;
 597
 598         if (!a || !b)
 599                 return false;
 600
 601         return !strcmp(a, b);
 602 }
 603
 604 struct probe_cache_entry *
 605 probe_cache__find(struct probe_cache *pcache, struct perf_probe_event *pev)
 606 {
 607         struct probe_cache_entry *entry = NULL;
 608         char *cmd = synthesize_perf_probe_command(pev);
 609
 610         if (!cmd)
 611                 return NULL;
 612
 613         for_each_probe_cache_entry(entry, pcache) {
 614                 if (pev->sdt) {
 615                         if (entry->pev.event &&
 616                             streql(entry->pev.event, pev->event) &&
 617                             (!pev->group ||
 618                              streql(entry->pev.group, pev->group)))
 619                                 goto found;
 620
 621                         continue;
 622                 }
 623                 /* Hit if same event name or same command-string */
 624                 if ((pev->event &&
 625                      (streql(entry->pev.group, pev->group) &&
 626                       streql(entry->pev.event, pev->event))) ||
 627                     (!strcmp(entry->spev, cmd)))
 628                         goto found;
 629         }
 630         entry = NULL;
 631
 632 found:
 633         free(cmd);
 634         return entry;
 635 }
 636
 637 struct probe_cache_entry *
 638 probe_cache__find_by_name(struct probe_cache *pcache,
 639                           const char *group, const char *event)
 640 {
 641         struct probe_cache_entry *entry = NULL;
 642
 643         for_each_probe_cache_entry(entry, pcache) {
 644                 /* Hit if same event name or same command-string */
 645                 if (streql(entry->pev.group, group) &&
 646                     streql(entry->pev.event, event))
 647                         goto found;
 648         }
 649         entry = NULL;
 650
 651 found:
 652         return entry;
 653 }
 654
 655 int probe_cache__add_entry(struct probe_cache *pcache,
 656                            struct perf_probe_event *pev,
 657                            struct probe_trace_event *tevs, int ntevs)
 658 {
 659         struct probe_cache_entry *entry = NULL;
 660         char *command;
 661         int i, ret = 0;
 662
 663         if (!pcache || !pev || !tevs || ntevs <= 0) {
 664                 ret = -EINVAL;
 665                 goto out_err;
 666         }
 667
 668         /* Remove old cache entry */
 669         entry = probe_cache__find(pcache, pev);
 670         if (entry) {
 671                 list_del_init(&entry->node);
 672                 probe_cache_entry__delete(entry);
 673         }
 674
 675         ret = -ENOMEM;
 676         entry = probe_cache_entry__new(pev);
 677         if (!entry)
 678                 goto out_err;
 679
 680         for (i = 0; i < ntevs; i++) {
 681                 if (!tevs[i].point.symbol)
 682                         continue;
 683
 684                 command = synthesize_probe_trace_command(&tevs[i]);
 685                 if (!command)
 686                         goto out_err;
 687                 ret = strlist__add(entry->tevlist, command);
 688                 if (ret == -ENOMEM) {
 689                         pr_err("strlist__add failed with -ENOMEM\n");
 690                         goto out_err;
 691                 }
 692
 693                 free(command);
 694         }
 695         list_add_tail(&entry->node, &pcache->entries);
 696         pr_debug("Added probe cache: %d\n", ntevs);
 697         return 0;
 698
 699 out_err:
 700         pr_debug("Failed to add probe caches\n");
 701         probe_cache_entry__delete(entry);
 702         return ret;
 703 }
 704
 705 #ifdef HAVE_GELF_GETNOTE_SUPPORT
 706 static unsigned long long sdt_note__get_addr(struct sdt_note *note)
 707 {
 708         return note->bit32 ?
 709                 (unsigned long long)note->addr.a32[SDT_NOTE_IDX_LOC] :
 710                 (unsigned long long)note->addr.a64[SDT_NOTE_IDX_LOC];
 711 }
 712
 713 static unsigned long long sdt_note__get_ref_ctr_offset(struct sdt_note *note)
 714 {
 715         return note->bit32 ?
 716                 (unsigned long long)note->addr.a32[SDT_NOTE_IDX_REFCTR] :
 717                 (unsigned long long)note->addr.a64[SDT_NOTE_IDX_REFCTR];
 718 }
 719
 720 static const char * const type_to_suffix[] = {
 721         ":s64", "", "", "", ":s32", "", ":s16", ":s8",
 722         "", ":u8", ":u16", "", ":u32", "", "", "", ":u64"
 723 };
 724
 725 /*
 726  * Isolate the string number and convert it into a decimal value;
 727  * this will be an index to get suffix of the uprobe name (defining
 728  * the type)
 729  */
 730 static int sdt_arg_parse_size(char *n_ptr, const char **suffix)
 731 {
 732         long type_idx;
 733
 734         type_idx = strtol(n_ptr, NULL, 10);
 735         if (type_idx < -8 || type_idx > 8) {
 736                 pr_debug4("Failed to get a valid sdt type\n");
 737                 return -1;
 738         }
 739
 740         *suffix = type_to_suffix[type_idx + 8];
 741         return 0;
 742 }
 743
 744 static int synthesize_sdt_probe_arg(struct strbuf *buf, int i, const char *arg)
 745 {
 746         char *op, *desc = strdup(arg), *new_op = NULL;
 747         const char *suffix = "";
 748         int ret = -1;
 749
 750         if (desc == NULL) {
 751                 pr_debug4("Allocation error\n");
 752                 return ret;
 753         }
 754
 755         /*
 756          * Argument is in N@OP format. N is size of the argument and OP is
 757          * the actual assembly operand. N can be omitted; in that case
 758          * argument is just OP(without @).
 759          */
 760         op = strchr(desc, '@');
 761         if (op) {
 762                 op[0] = '\0';
 763                 op++;
 764
 765                 if (sdt_arg_parse_size(desc, &suffix))
 766                         goto error;
 767         } else {
 768                 op = desc;
 769         }
 770
 771         ret = arch_sdt_arg_parse_op(op, &new_op);
 772
 773         if (ret < 0)
 774                 goto error;
 775
 776         if (ret == SDT_ARG_VALID) {
 777                 ret = strbuf_addf(buf, " arg%d=%s%s", i + 1, new_op, suffix);
 778                 if (ret < 0)
 779                         goto error;
 780         }
 781
 782         ret = 0;
 783 error:
 784         free(desc);
 785         free(new_op);
 786         return ret;
 787 }
 788
 789 static char *synthesize_sdt_probe_command(struct sdt_note *note,
 790                                         const char *pathname,
 791                                         const char *sdtgrp)
 792 {
 793         struct strbuf buf;
 794         char *ret = NULL, **args;
 795         int i, args_count, err;
 796         unsigned long long ref_ctr_offset;
 797
 798         if (strbuf_init(&buf, 32) < 0)
 799                 return NULL;
 800
 801         err = strbuf_addf(&buf, "p:%s/%s %s:0x%llx",
 802                         sdtgrp, note->name, pathname,
 803                         sdt_note__get_addr(note));
 804
 805         ref_ctr_offset = sdt_note__get_ref_ctr_offset(note);
 806         if (ref_ctr_offset && err >= 0)
 807                 err = strbuf_addf(&buf, "(0x%llx)", ref_ctr_offset);
 808
 809         if (err < 0)
 810                 goto error;
 811
 812         if (!note->args)
 813                 goto out;
 814
 815         if (note->args) {
 816                 args = argv_split(note->args, &args_count);
 817
 818                 for (i = 0; i < args_count; ++i) {
 819                         if (synthesize_sdt_probe_arg(&buf, i, args[i]) < 0)
 820                                 goto error;
 821                 }
 822         }
 823
 824 out:
 825         ret = strbuf_detach(&buf, NULL);
 826 error:
 827         strbuf_release(&buf);
 828         return ret;
 829 }
 830
 831 int probe_cache__scan_sdt(struct probe_cache *pcache, const char *pathname)
 832 {
 833         struct probe_cache_entry *entry = NULL;
 834         struct list_head sdtlist;
 835         struct sdt_note *note;
 836         char *buf;
 837         char sdtgrp[64];
 838         int ret;
 839
 840         INIT_LIST_HEAD(&sdtlist);
 841         ret = get_sdt_note_list(&sdtlist, pathname);
 842         if (ret < 0) {
 843                 pr_debug4("Failed to get sdt note: %d\n", ret);
 844                 return ret;
 845         }
 846         list_for_each_entry(note, &sdtlist, note_list) {
 847                 ret = snprintf(sdtgrp, 64, "sdt_%s", note->provider);
 848                 if (ret < 0)
 849                         break;
 850                 /* Try to find same-name entry */
 851                 entry = probe_cache__find_by_name(pcache, sdtgrp, note->name);
 852                 if (!entry) {
 853                         entry = probe_cache_entry__new(NULL);
 854                         if (!entry) {
 855                                 ret = -ENOMEM;
 856                                 break;
 857                         }
 858                         entry->sdt = true;
 859                         ret = asprintf(&entry->spev, "%s:%s=%s", sdtgrp,
 860                                         note->name, note->name);
 861                         if (ret < 0)
 862                                 break;
 863                         entry->pev.event = strdup(note->name);
 864                         entry->pev.group = strdup(sdtgrp);
 865                         list_add_tail(&entry->node, &pcache->entries);
 866                 }
 867                 buf = synthesize_sdt_probe_command(note, pathname, sdtgrp);
 868                 if (!buf) {
 869                         ret = -ENOMEM;
 870                         break;
 871                 }
 872
 873                 ret = strlist__add(entry->tevlist, buf);
 874
 875                 free(buf);
 876                 entry = NULL;
 877
 878                 if (ret == -ENOMEM) {
 879                         pr_err("strlist__add failed with -ENOMEM\n");
 880                         break;
 881                 }
 882         }
 883         if (entry) {
 884                 list_del_init(&entry->node);
 885                 probe_cache_entry__delete(entry);
 886         }
 887         cleanup_sdt_note_list(&sdtlist);
 888         return ret;
 889 }
 890 #endif
 891
 892 static int probe_cache_entry__write(struct probe_cache_entry *entry, int fd)
 893 {
 894         struct str_node *snode;
 895         struct stat st;
 896         struct iovec iov[3];
 897         const char *prefix = entry->sdt ? "%" : "#";
 898         int ret;
 899         /* Save stat for rollback */
 900         ret = fstat(fd, &st);
 901         if (ret < 0)
 902                 return ret;
 903
 904         pr_debug("Writing cache: %s%s\n", prefix, entry->spev);
 905         iov[0].iov_base = (void *)prefix; iov[0].iov_len = 1;
 906         iov[1].iov_base = entry->spev; iov[1].iov_len = strlen(entry->spev);
 907         iov[2].iov_base = (void *)"\n"; iov[2].iov_len = 1;
 908         ret = writev(fd, iov, 3);
 909         if (ret < (int)iov[1].iov_len + 2)
 910                 goto rollback;
 911
 912         strlist__for_each_entry(snode, entry->tevlist) {
 913                 iov[0].iov_base = (void *)snode->s;
 914                 iov[0].iov_len = strlen(snode->s);
 915                 iov[1].iov_base = (void *)"\n"; iov[1].iov_len = 1;
 916                 ret = writev(fd, iov, 2);
 917                 if (ret < (int)iov[0].iov_len + 1)
 918                         goto rollback;
 919         }
 920         return 0;
 921
 922 rollback:
 923         /* Rollback to avoid cache file corruption */
 924         if (ret > 0)
 925                 ret = -1;
 926         if (ftruncate(fd, st.st_size) < 0)
 927                 ret = -2;
 928
 929         return ret;
 930 }
 931
 932 int probe_cache__commit(struct probe_cache *pcache)
 933 {
 934         struct probe_cache_entry *entry;
 935         int ret = 0;
 936
 937         /* TBD: if we do not update existing entries, skip it */
 938         ret = lseek(pcache->fd, 0, SEEK_SET);
 939         if (ret < 0)
 940                 goto out;
 941
 942         ret = ftruncate(pcache->fd, 0);
 943         if (ret < 0)
 944                 goto out;
 945
 946         for_each_probe_cache_entry(entry, pcache) {
 947                 ret = probe_cache_entry__write(entry, pcache->fd);
 948                 pr_debug("Cache committed: %d\n", ret);
 949                 if (ret < 0)
 950                         break;
 951         }
 952 out:
 953         return ret;
 954 }
 955
 956 static bool probe_cache_entry__compare(struct probe_cache_entry *entry,
 957                                        struct strfilter *filter)
 958 {
 959         char buf[128], *ptr = entry->spev;
 960
 961         if (entry->pev.event) {
 962                 snprintf(buf, 128, "%s:%s", entry->pev.group, entry->pev.event);
 963                 ptr = buf;
 964         }
 965         return strfilter__compare(filter, ptr);
 966 }
 967
 968 int probe_cache__filter_purge(struct probe_cache *pcache,
 969                               struct strfilter *filter)
 970 {
 971         struct probe_cache_entry *entry, *tmp;
 972
 973         list_for_each_entry_safe(entry, tmp, &pcache->entries, node) {
 974                 if (probe_cache_entry__compare(entry, filter)) {
 975                         pr_info("Removed cached event: %s\n", entry->spev);
 976                         list_del_init(&entry->node);
 977                         probe_cache_entry__delete(entry);
 978                 }
 979         }
 980         return 0;
 981 }
 982
 983 static int probe_cache__show_entries(struct probe_cache *pcache,
 984                                      struct strfilter *filter)
 985 {
 986         struct probe_cache_entry *entry;
 987
 988         for_each_probe_cache_entry(entry, pcache) {
 989                 if (probe_cache_entry__compare(entry, filter))
 990                         printf("%s\n", entry->spev);
 991         }
 992         return 0;
 993 }
 994
 995 /* Show all cached probes */
 996 int probe_cache__show_all_caches(struct strfilter *filter)
 997 {
 998         struct probe_cache *pcache;
 999         struct strlist *bidlist;
1000         struct str_node *nd;
1001         char *buf = strfilter__string(filter);
1002
1003         pr_debug("list cache with filter: %s\n", buf);
1004         free(buf);
1005
1006         bidlist = build_id_cache__list_all(true);
1007         if (!bidlist) {
1008                 pr_debug("Failed to get buildids: %d\n", errno);
1009                 return -EINVAL;
1010         }
1011         strlist__for_each_entry(nd, bidlist) {
1012                 pcache = probe_cache__new(nd->s, NULL);
1013                 if (!pcache)
1014                         continue;
1015                 if (!list_empty(&pcache->entries)) {
1016                         buf = build_id_cache__origname(nd->s);
1017                         printf("%s (%s):\n", buf, nd->s);
1018                         free(buf);
1019                         probe_cache__show_entries(pcache, filter);
1020                 }
1021                 probe_cache__delete(pcache);
1022         }
1023         strlist__delete(bidlist);
1024
1025         return 0;
1026 }
1027
1028 enum ftrace_readme {
1029         FTRACE_README_PROBE_TYPE_X = 0,
1030         FTRACE_README_KRETPROBE_OFFSET,
1031         FTRACE_README_UPROBE_REF_CTR,
1032         FTRACE_README_USER_ACCESS,
1033         FTRACE_README_MULTIPROBE_EVENT,
1034         FTRACE_README_IMMEDIATE_VALUE,
1035         FTRACE_README_END,
1036 };
1037
1038 static struct {
1039         const char *pattern;
1040         bool avail;
1041 } ftrace_readme_table[] = {
1042 #define DEFINE_TYPE(idx, pat)                   \
1043         [idx] = {.pattern = pat, .avail = false}
1044         DEFINE_TYPE(FTRACE_README_PROBE_TYPE_X, "*type: * x8/16/32/64,*"),
1045         DEFINE_TYPE(FTRACE_README_KRETPROBE_OFFSET, "*place (kretprobe): *"),
1046         DEFINE_TYPE(FTRACE_README_UPROBE_REF_CTR, "*ref_ctr_offset*"),
1047         DEFINE_TYPE(FTRACE_README_USER_ACCESS, "*u]<offset>*"),
1048         DEFINE_TYPE(FTRACE_README_MULTIPROBE_EVENT, "*Create/append/*"),
1049         DEFINE_TYPE(FTRACE_README_IMMEDIATE_VALUE, "*\\imm-value,*"),
1050 };
1051
1052 static bool scan_ftrace_readme(enum ftrace_readme type)
1053 {
1054         int fd;
1055         FILE *fp;
1056         char *buf = NULL;
1057         size_t len = 0;
1058         bool ret = false;
1059         static bool scanned = false;
1060
1061         if (scanned)
1062                 goto result;
1063
1064         fd = open_trace_file("README", false);
1065         if (fd < 0)
1066                 return ret;
1067
1068         fp = fdopen(fd, "r");
1069         if (!fp) {
1070                 close(fd);
1071                 return ret;
1072         }
1073
1074         while (getline(&buf, &len, fp) > 0)
1075                 for (enum ftrace_readme i = 0; i < FTRACE_README_END; i++)
1076                         if (!ftrace_readme_table[i].avail)
1077                                 ftrace_readme_table[i].avail =
1078                                         strglobmatch(buf, ftrace_readme_table[i].pattern);
1079         scanned = true;
1080
1081         fclose(fp);
1082         free(buf);
1083
1084 result:
1085         if (type >= FTRACE_README_END)
1086                 return false;
1087
1088         return ftrace_readme_table[type].avail;
1089 }
1090
1091 bool probe_type_is_available(enum probe_type type)
1092 {
1093         if (type >= PROBE_TYPE_END)
1094                 return false;
1095         else if (type == PROBE_TYPE_X)
1096                 return scan_ftrace_readme(FTRACE_README_PROBE_TYPE_X);
1097
1098         return true;
1099 }
1100
1101 bool kretprobe_offset_is_supported(void)
1102 {
1103         return scan_ftrace_readme(FTRACE_README_KRETPROBE_OFFSET);
1104 }
1105
1106 bool uprobe_ref_ctr_is_supported(void)
1107 {
1108         return scan_ftrace_readme(FTRACE_README_UPROBE_REF_CTR);
1109 }
1110
1111 bool user_access_is_supported(void)
1112 {
1113         return scan_ftrace_readme(FTRACE_README_USER_ACCESS);
1114 }
1115
1116 bool multiprobe_event_is_supported(void)
1117 {
1118         return scan_ftrace_readme(FTRACE_README_MULTIPROBE_EVENT);
1119 }
1120
1121 bool immediate_value_is_supported(void)
1122 {
1123         return scan_ftrace_readme(FTRACE_README_IMMEDIATE_VALUE);
1124 }