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