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 <fcntl.h>
  19 #include <sys/stat.h>
  20 #include <sys/types.h>
  21 #include <sys/uio.h>
  22 #include <unistd.h>
  23 #include "util.h"
  24 #include "event.h"
  25 #include "strlist.h"
  26 #include "strfilter.h"
  27 #include "debug.h"
  28 #include "cache.h"
  29 #include "color.h"
  30 #include "symbol.h"
  31 #include "thread.h"
  32 #include <api/fs/tracing_path.h>
  33 #include "probe-event.h"
  34 #include "probe-file.h"
  35 #include "session.h"
  36 #include "perf_regs.h"
  37 #include "string2.h"
  38
  39 /* 4096 - 2 ('\n' + '\0') */
  40 #define MAX_CMDLEN 4094
  41
  42 static void print_open_warning(int err, bool uprobe)
  43 {
  44         char sbuf[STRERR_BUFSIZE];
  45
  46         if (err == -ENOENT) {
  47                 const char *config;
  48
  49                 if (uprobe)
  50                         config = "CONFIG_UPROBE_EVENTS";
  51                 else
  52                         config = "CONFIG_KPROBE_EVENTS";
  53
  54                 pr_warning("%cprobe_events file does not exist"
  55                            " - please rebuild kernel with %s.\n",
  56                            uprobe ? 'u' : 'k', config);
  57         } else if (err == -ENOTSUP)
  58                 pr_warning("Tracefs or debugfs is not mounted.\n");
  59         else
  60                 pr_warning("Failed to open %cprobe_events: %s\n",
  61                            uprobe ? 'u' : 'k',
  62                            str_error_r(-err, sbuf, sizeof(sbuf)));
  63 }
  64
  65 static void print_both_open_warning(int kerr, int uerr)
  66 {
  67         /* Both kprobes and uprobes are disabled, warn it. */
  68         if (kerr == -ENOTSUP && uerr == -ENOTSUP)
  69                 pr_warning("Tracefs or debugfs is not mounted.\n");
  70         else if (kerr == -ENOENT && uerr == -ENOENT)
  71                 pr_warning("Please rebuild kernel with CONFIG_KPROBE_EVENTS "
  72                            "or/and CONFIG_UPROBE_EVENTS.\n");
  73         else {
  74                 char sbuf[STRERR_BUFSIZE];
  75                 pr_warning("Failed to open kprobe events: %s.\n",
  76                            str_error_r(-kerr, sbuf, sizeof(sbuf)));
  77                 pr_warning("Failed to open uprobe events: %s.\n",
  78                            str_error_r(-uerr, sbuf, sizeof(sbuf)));
  79         }
  80 }
  81
  82 int open_trace_file(const char *trace_file, bool readwrite)
  83 {
  84         char buf[PATH_MAX];
  85         int ret;
  86
  87         ret = e_snprintf(buf, PATH_MAX, "%s/%s", tracing_path_mount(), 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                              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                 strncpy(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                         strlist__add(entry->tevlist, buf);
 523                 }
 524         }
 525 out:
 526         fclose(fp);
 527         return ret;
 528 }
 529
 530 static struct probe_cache *probe_cache__alloc(void)
 531 {
 532         struct probe_cache *pcache = zalloc(sizeof(*pcache));
 533
 534         if (pcache) {
 535                 INIT_LIST_HEAD(&pcache->entries);
 536                 pcache->fd = -EINVAL;
 537         }
 538         return pcache;
 539 }
 540
 541 void probe_cache__purge(struct probe_cache *pcache)
 542 {
 543         struct probe_cache_entry *entry, *n;
 544
 545         list_for_each_entry_safe(entry, n, &pcache->entries, node) {
 546                 list_del_init(&entry->node);
 547                 probe_cache_entry__delete(entry);
 548         }
 549 }
 550
 551 void probe_cache__delete(struct probe_cache *pcache)
 552 {
 553         if (!pcache)
 554                 return;
 555
 556         probe_cache__purge(pcache);
 557         if (pcache->fd > 0)
 558                 close(pcache->fd);
 559         free(pcache);
 560 }
 561
 562 struct probe_cache *probe_cache__new(const char *target, struct nsinfo *nsi)
 563 {
 564         struct probe_cache *pcache = probe_cache__alloc();
 565         int ret;
 566
 567         if (!pcache)
 568                 return NULL;
 569
 570         ret = probe_cache__open(pcache, target, nsi);
 571         if (ret < 0) {
 572                 pr_debug("Cache open error: %d\n", ret);
 573                 goto out_err;
 574         }
 575
 576         ret = probe_cache__load(pcache);
 577         if (ret < 0) {
 578                 pr_debug("Cache read error: %d\n", ret);
 579                 goto out_err;
 580         }
 581
 582         return pcache;
 583
 584 out_err:
 585         probe_cache__delete(pcache);
 586         return NULL;
 587 }
 588
 589 static bool streql(const char *a, const char *b)
 590 {
 591         if (a == b)
 592                 return true;
 593
 594         if (!a || !b)
 595                 return false;
 596
 597         return !strcmp(a, b);
 598 }
 599
 600 struct probe_cache_entry *
 601 probe_cache__find(struct probe_cache *pcache, struct perf_probe_event *pev)
 602 {
 603         struct probe_cache_entry *entry = NULL;
 604         char *cmd = synthesize_perf_probe_command(pev);
 605
 606         if (!cmd)
 607                 return NULL;
 608
 609         for_each_probe_cache_entry(entry, pcache) {
 610                 if (pev->sdt) {
 611                         if (entry->pev.event &&
 612                             streql(entry->pev.event, pev->event) &&
 613                             (!pev->group ||
 614                              streql(entry->pev.group, pev->group)))
 615                                 goto found;
 616
 617                         continue;
 618                 }
 619                 /* Hit if same event name or same command-string */
 620                 if ((pev->event &&
 621                      (streql(entry->pev.group, pev->group) &&
 622                       streql(entry->pev.event, pev->event))) ||
 623                     (!strcmp(entry->spev, cmd)))
 624                         goto found;
 625         }
 626         entry = NULL;
 627
 628 found:
 629         free(cmd);
 630         return entry;
 631 }
 632
 633 struct probe_cache_entry *
 634 probe_cache__find_by_name(struct probe_cache *pcache,
 635                           const char *group, const char *event)
 636 {
 637         struct probe_cache_entry *entry = NULL;
 638
 639         for_each_probe_cache_entry(entry, pcache) {
 640                 /* Hit if same event name or same command-string */
 641                 if (streql(entry->pev.group, group) &&
 642                     streql(entry->pev.event, event))
 643                         goto found;
 644         }
 645         entry = NULL;
 646
 647 found:
 648         return entry;
 649 }
 650
 651 int probe_cache__add_entry(struct probe_cache *pcache,
 652                            struct perf_probe_event *pev,
 653                            struct probe_trace_event *tevs, int ntevs)
 654 {
 655         struct probe_cache_entry *entry = NULL;
 656         char *command;
 657         int i, ret = 0;
 658
 659         if (!pcache || !pev || !tevs || ntevs <= 0) {
 660                 ret = -EINVAL;
 661                 goto out_err;
 662         }
 663
 664         /* Remove old cache entry */
 665         entry = probe_cache__find(pcache, pev);
 666         if (entry) {
 667                 list_del_init(&entry->node);
 668                 probe_cache_entry__delete(entry);
 669         }
 670
 671         ret = -ENOMEM;
 672         entry = probe_cache_entry__new(pev);
 673         if (!entry)
 674                 goto out_err;
 675
 676         for (i = 0; i < ntevs; i++) {
 677                 if (!tevs[i].point.symbol)
 678                         continue;
 679
 680                 command = synthesize_probe_trace_command(&tevs[i]);
 681                 if (!command)
 682                         goto out_err;
 683                 strlist__add(entry->tevlist, command);
 684                 free(command);
 685         }
 686         list_add_tail(&entry->node, &pcache->entries);
 687         pr_debug("Added probe cache: %d\n", ntevs);
 688         return 0;
 689
 690 out_err:
 691         pr_debug("Failed to add probe caches\n");
 692         probe_cache_entry__delete(entry);
 693         return ret;
 694 }
 695
 696 #ifdef HAVE_GELF_GETNOTE_SUPPORT
 697 static unsigned long long sdt_note__get_addr(struct sdt_note *note)
 698 {
 699         return note->bit32 ?
 700                 (unsigned long long)note->addr.a32[SDT_NOTE_IDX_LOC] :
 701                 (unsigned long long)note->addr.a64[SDT_NOTE_IDX_LOC];
 702 }
 703
 704 static unsigned long long sdt_note__get_ref_ctr_offset(struct sdt_note *note)
 705 {
 706         return note->bit32 ?
 707                 (unsigned long long)note->addr.a32[SDT_NOTE_IDX_REFCTR] :
 708                 (unsigned long long)note->addr.a64[SDT_NOTE_IDX_REFCTR];
 709 }
 710
 711 static const char * const type_to_suffix[] = {
 712         ":s64", "", "", "", ":s32", "", ":s16", ":s8",
 713         "", ":u8", ":u16", "", ":u32", "", "", "", ":u64"
 714 };
 715
 716 /*
 717  * Isolate the string number and convert it into a decimal value;
 718  * this will be an index to get suffix of the uprobe name (defining
 719  * the type)
 720  */
 721 static int sdt_arg_parse_size(char *n_ptr, const char **suffix)
 722 {
 723         long type_idx;
 724
 725         type_idx = strtol(n_ptr, NULL, 10);
 726         if (type_idx < -8 || type_idx > 8) {
 727                 pr_debug4("Failed to get a valid sdt type\n");
 728                 return -1;
 729         }
 730
 731         *suffix = type_to_suffix[type_idx + 8];
 732         return 0;
 733 }
 734
 735 static int synthesize_sdt_probe_arg(struct strbuf *buf, int i, const char *arg)
 736 {
 737         char *op, *desc = strdup(arg), *new_op = NULL;
 738         const char *suffix = "";
 739         int ret = -1;
 740
 741         if (desc == NULL) {
 742                 pr_debug4("Allocation error\n");
 743                 return ret;
 744         }
 745
 746         /*
 747          * Argument is in N@OP format. N is size of the argument and OP is
 748          * the actual assembly operand. N can be omitted; in that case
 749          * argument is just OP(without @).
 750          */
 751         op = strchr(desc, '@');
 752         if (op) {
 753                 op[0] = '\0';
 754                 op++;
 755
 756                 if (sdt_arg_parse_size(desc, &suffix))
 757                         goto error;
 758         } else {
 759                 op = desc;
 760         }
 761
 762         ret = arch_sdt_arg_parse_op(op, &new_op);
 763
 764         if (ret < 0)
 765                 goto error;
 766
 767         if (ret == SDT_ARG_VALID) {
 768                 ret = strbuf_addf(buf, " arg%d=%s%s", i + 1, new_op, suffix);
 769                 if (ret < 0)
 770                         goto error;
 771         }
 772
 773         ret = 0;
 774 error:
 775         free(desc);
 776         free(new_op);
 777         return ret;
 778 }
 779
 780 static char *synthesize_sdt_probe_command(struct sdt_note *note,
 781                                         const char *pathname,
 782                                         const char *sdtgrp)
 783 {
 784         struct strbuf buf;
 785         char *ret = NULL, **args;
 786         int i, args_count, err;
 787         unsigned long long ref_ctr_offset;
 788
 789         if (strbuf_init(&buf, 32) < 0)
 790                 return NULL;
 791
 792         err = strbuf_addf(&buf, "p:%s/%s %s:0x%llx",
 793                         sdtgrp, note->name, pathname,
 794                         sdt_note__get_addr(note));
 795
 796         ref_ctr_offset = sdt_note__get_ref_ctr_offset(note);
 797         if (ref_ctr_offset && err >= 0)
 798                 err = strbuf_addf(&buf, "(0x%llx)", ref_ctr_offset);
 799
 800         if (err < 0)
 801                 goto error;
 802
 803         if (!note->args)
 804                 goto out;
 805
 806         if (note->args) {
 807                 args = argv_split(note->args, &args_count);
 808
 809                 for (i = 0; i < args_count; ++i) {
 810                         if (synthesize_sdt_probe_arg(&buf, i, args[i]) < 0)
 811                                 goto error;
 812                 }
 813         }
 814
 815 out:
 816         ret = strbuf_detach(&buf, NULL);
 817 error:
 818         strbuf_release(&buf);
 819         return ret;
 820 }
 821
 822 int probe_cache__scan_sdt(struct probe_cache *pcache, const char *pathname)
 823 {
 824         struct probe_cache_entry *entry = NULL;
 825         struct list_head sdtlist;
 826         struct sdt_note *note;
 827         char *buf;
 828         char sdtgrp[64];
 829         int ret;
 830
 831         INIT_LIST_HEAD(&sdtlist);
 832         ret = get_sdt_note_list(&sdtlist, pathname);
 833         if (ret < 0) {
 834                 pr_debug4("Failed to get sdt note: %d\n", ret);
 835                 return ret;
 836         }
 837         list_for_each_entry(note, &sdtlist, note_list) {
 838                 ret = snprintf(sdtgrp, 64, "sdt_%s", note->provider);
 839                 if (ret < 0)
 840                         break;
 841                 /* Try to find same-name entry */
 842                 entry = probe_cache__find_by_name(pcache, sdtgrp, note->name);
 843                 if (!entry) {
 844                         entry = probe_cache_entry__new(NULL);
 845                         if (!entry) {
 846                                 ret = -ENOMEM;
 847                                 break;
 848                         }
 849                         entry->sdt = true;
 850                         ret = asprintf(&entry->spev, "%s:%s=%s", sdtgrp,
 851                                         note->name, note->name);
 852                         if (ret < 0)
 853                                 break;
 854                         entry->pev.event = strdup(note->name);
 855                         entry->pev.group = strdup(sdtgrp);
 856                         list_add_tail(&entry->node, &pcache->entries);
 857                 }
 858                 buf = synthesize_sdt_probe_command(note, pathname, sdtgrp);
 859                 if (!buf) {
 860                         ret = -ENOMEM;
 861                         break;
 862                 }
 863
 864                 strlist__add(entry->tevlist, buf);
 865                 free(buf);
 866                 entry = NULL;
 867         }
 868         if (entry) {
 869                 list_del_init(&entry->node);
 870                 probe_cache_entry__delete(entry);
 871         }
 872         cleanup_sdt_note_list(&sdtlist);
 873         return ret;
 874 }
 875 #endif
 876
 877 static int probe_cache_entry__write(struct probe_cache_entry *entry, int fd)
 878 {
 879         struct str_node *snode;
 880         struct stat st;
 881         struct iovec iov[3];
 882         const char *prefix = entry->sdt ? "%" : "#";
 883         int ret;
 884         /* Save stat for rollback */
 885         ret = fstat(fd, &st);
 886         if (ret < 0)
 887                 return ret;
 888
 889         pr_debug("Writing cache: %s%s\n", prefix, entry->spev);
 890         iov[0].iov_base = (void *)prefix; iov[0].iov_len = 1;
 891         iov[1].iov_base = entry->spev; iov[1].iov_len = strlen(entry->spev);
 892         iov[2].iov_base = (void *)"\n"; iov[2].iov_len = 1;
 893         ret = writev(fd, iov, 3);
 894         if (ret < (int)iov[1].iov_len + 2)
 895                 goto rollback;
 896
 897         strlist__for_each_entry(snode, entry->tevlist) {
 898                 iov[0].iov_base = (void *)snode->s;
 899                 iov[0].iov_len = strlen(snode->s);
 900                 iov[1].iov_base = (void *)"\n"; iov[1].iov_len = 1;
 901                 ret = writev(fd, iov, 2);
 902                 if (ret < (int)iov[0].iov_len + 1)
 903                         goto rollback;
 904         }
 905         return 0;
 906
 907 rollback:
 908         /* Rollback to avoid cache file corruption */
 909         if (ret > 0)
 910                 ret = -1;
 911         if (ftruncate(fd, st.st_size) < 0)
 912                 ret = -2;
 913
 914         return ret;
 915 }
 916
 917 int probe_cache__commit(struct probe_cache *pcache)
 918 {
 919         struct probe_cache_entry *entry;
 920         int ret = 0;
 921
 922         /* TBD: if we do not update existing entries, skip it */
 923         ret = lseek(pcache->fd, 0, SEEK_SET);
 924         if (ret < 0)
 925                 goto out;
 926
 927         ret = ftruncate(pcache->fd, 0);
 928         if (ret < 0)
 929                 goto out;
 930
 931         for_each_probe_cache_entry(entry, pcache) {
 932                 ret = probe_cache_entry__write(entry, pcache->fd);
 933                 pr_debug("Cache committed: %d\n", ret);
 934                 if (ret < 0)
 935                         break;
 936         }
 937 out:
 938         return ret;
 939 }
 940
 941 static bool probe_cache_entry__compare(struct probe_cache_entry *entry,
 942                                        struct strfilter *filter)
 943 {
 944         char buf[128], *ptr = entry->spev;
 945
 946         if (entry->pev.event) {
 947                 snprintf(buf, 128, "%s:%s", entry->pev.group, entry->pev.event);
 948                 ptr = buf;
 949         }
 950         return strfilter__compare(filter, ptr);
 951 }
 952
 953 int probe_cache__filter_purge(struct probe_cache *pcache,
 954                               struct strfilter *filter)
 955 {
 956         struct probe_cache_entry *entry, *tmp;
 957
 958         list_for_each_entry_safe(entry, tmp, &pcache->entries, node) {
 959                 if (probe_cache_entry__compare(entry, filter)) {
 960                         pr_info("Removed cached event: %s\n", entry->spev);
 961                         list_del_init(&entry->node);
 962                         probe_cache_entry__delete(entry);
 963                 }
 964         }
 965         return 0;
 966 }
 967
 968 static int probe_cache__show_entries(struct probe_cache *pcache,
 969                                      struct strfilter *filter)
 970 {
 971         struct probe_cache_entry *entry;
 972
 973         for_each_probe_cache_entry(entry, pcache) {
 974                 if (probe_cache_entry__compare(entry, filter))
 975                         printf("%s\n", entry->spev);
 976         }
 977         return 0;
 978 }
 979
 980 /* Show all cached probes */
 981 int probe_cache__show_all_caches(struct strfilter *filter)
 982 {
 983         struct probe_cache *pcache;
 984         struct strlist *bidlist;
 985         struct str_node *nd;
 986         char *buf = strfilter__string(filter);
 987
 988         pr_debug("list cache with filter: %s\n", buf);
 989         free(buf);
 990
 991         bidlist = build_id_cache__list_all(true);
 992         if (!bidlist) {
 993                 pr_debug("Failed to get buildids: %d\n", errno);
 994                 return -EINVAL;
 995         }
 996         strlist__for_each_entry(nd, bidlist) {
 997                 pcache = probe_cache__new(nd->s, NULL);
 998                 if (!pcache)
 999                         continue;
1000                 if (!list_empty(&pcache->entries)) {
1001                         buf = build_id_cache__origname(nd->s);
1002                         printf("%s (%s):\n", buf, nd->s);
1003                         free(buf);
1004                         probe_cache__show_entries(pcache, filter);
1005                 }
1006                 probe_cache__delete(pcache);
1007         }
1008         strlist__delete(bidlist);
1009
1010         return 0;
1011 }
1012
1013 enum ftrace_readme {
1014         FTRACE_README_PROBE_TYPE_X = 0,
1015         FTRACE_README_KRETPROBE_OFFSET,
1016         FTRACE_README_UPROBE_REF_CTR,
1017         FTRACE_README_END,
1018 };
1019
1020 static struct {
1021         const char *pattern;
1022         bool avail;
1023 } ftrace_readme_table[] = {
1024 #define DEFINE_TYPE(idx, pat)                   \
1025         [idx] = {.pattern = pat, .avail = false}
1026         DEFINE_TYPE(FTRACE_README_PROBE_TYPE_X, "*type: * x8/16/32/64,*"),
1027         DEFINE_TYPE(FTRACE_README_KRETPROBE_OFFSET, "*place (kretprobe): *"),
1028         DEFINE_TYPE(FTRACE_README_UPROBE_REF_CTR, "*ref_ctr_offset*"),
1029 };
1030
1031 static bool scan_ftrace_readme(enum ftrace_readme type)
1032 {
1033         int fd;
1034         FILE *fp;
1035         char *buf = NULL;
1036         size_t len = 0;
1037         bool ret = false;
1038         static bool scanned = false;
1039
1040         if (scanned)
1041                 goto result;
1042
1043         fd = open_trace_file("README", false);
1044         if (fd < 0)
1045                 return ret;
1046
1047         fp = fdopen(fd, "r");
1048         if (!fp) {
1049                 close(fd);
1050                 return ret;
1051         }
1052
1053         while (getline(&buf, &len, fp) > 0)
1054                 for (enum ftrace_readme i = 0; i < FTRACE_README_END; i++)
1055                         if (!ftrace_readme_table[i].avail)
1056                                 ftrace_readme_table[i].avail =
1057                                         strglobmatch(buf, ftrace_readme_table[i].pattern);
1058         scanned = true;
1059
1060         fclose(fp);
1061         free(buf);
1062
1063 result:
1064         if (type >= FTRACE_README_END)
1065                 return false;
1066
1067         return ftrace_readme_table[type].avail;
1068 }
1069
1070 bool probe_type_is_available(enum probe_type type)
1071 {
1072         if (type >= PROBE_TYPE_END)
1073                 return false;
1074         else if (type == PROBE_TYPE_X)
1075                 return scan_ftrace_readme(FTRACE_README_PROBE_TYPE_X);
1076
1077         return true;
1078 }
1079
1080 bool kretprobe_offset_is_supported(void)
1081 {
1082         return scan_ftrace_readme(FTRACE_README_KRETPROBE_OFFSET);
1083 }
1084
1085 bool uprobe_ref_ctr_is_supported(void)
1086 {
1087         return scan_ftrace_readme(FTRACE_README_UPROBE_REF_CTR);
1088 }