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 <api/fs/fs.h>
  26 #include "probe-event.h"
  27 #include "probe-file.h"
  28 #include "session.h"
  29 #include "perf_regs.h"
  30 #include "string2.h"
  31
  32 /* 4096 - 2 ('\n' + '\0') */
  33 #define MAX_CMDLEN 4094
  34
  35 static bool print_common_warning(int err, bool readwrite)
  36 {
  37         if (err == -EACCES)
  38                 pr_warning("No permission to %s tracefs.\nPlease %s\n",
  39                            readwrite ? "write" : "read",
  40                            readwrite ? "run this command again with sudo." :
  41                                        "try 'sudo mount -o remount,mode=755 /sys/kernel/tracing/'");
  42         else
  43                 return false;
  44
  45         return true;
  46 }
  47
  48 static bool print_configure_probe_event(int kerr, int uerr)
  49 {
  50         const char *config, *file;
  51
  52         if (kerr == -ENOENT && uerr == -ENOENT) {
  53                 file = "{k,u}probe_events";
  54                 config = "CONFIG_KPROBE_EVENTS=y and CONFIG_UPROBE_EVENTS=y";
  55         } else if (kerr == -ENOENT) {
  56                 file = "kprobe_events";
  57                 config = "CONFIG_KPROBE_EVENTS=y";
  58         } else if (uerr == -ENOENT) {
  59                 file = "uprobe_events";
  60                 config = "CONFIG_UPROBE_EVENTS=y";
  61         } else
  62                 return false;
  63
  64         if (!debugfs__configured() && !tracefs__configured())
  65                 pr_warning("Debugfs or tracefs is not mounted\n"
  66                            "Please try 'sudo mount -t tracefs nodev /sys/kernel/tracing/'\n");
  67         else
  68                 pr_warning("%s/%s does not exist.\nPlease rebuild kernel with %s.\n",
  69                            tracing_path_mount(), file, config);
  70
  71         return true;
  72 }
  73
  74 static void print_open_warning(int err, bool uprobe, bool readwrite)
  75 {
  76         char sbuf[STRERR_BUFSIZE];
  77
  78         if (print_common_warning(err, readwrite))
  79                 return;
  80
  81         if (print_configure_probe_event(uprobe ? 0 : err, uprobe ? err : 0))
  82                 return;
  83
  84         pr_warning("Failed to open %s/%cprobe_events: %s\n",
  85                    tracing_path_mount(), uprobe ? 'u' : 'k',
  86                    str_error_r(-err, sbuf, sizeof(sbuf)));
  87 }
  88
  89 static void print_both_open_warning(int kerr, int uerr, bool readwrite)
  90 {
  91         char sbuf[STRERR_BUFSIZE];
  92
  93         if (kerr == uerr && print_common_warning(kerr, readwrite))
  94                 return;
  95
  96         if (print_configure_probe_event(kerr, uerr))
  97                 return;
  98
  99         if (kerr < 0)
 100                 pr_warning("Failed to open %s/kprobe_events: %s.\n",
 101                            tracing_path_mount(),
 102                            str_error_r(-kerr, sbuf, sizeof(sbuf)));
 103         if (uerr < 0)
 104                 pr_warning("Failed to open %s/uprobe_events: %s.\n",
 105                            tracing_path_mount(),
 106                            str_error_r(-uerr, sbuf, sizeof(sbuf)));
 107 }
 108
 109 int open_trace_file(const char *trace_file, bool readwrite)
 110 {
 111         char buf[PATH_MAX];
 112         int ret;
 113
 114         ret = e_snprintf(buf, PATH_MAX, "%s/%s", tracing_path_mount(), trace_file);
 115         if (ret >= 0) {
 116                 pr_debug("Opening %s write=%d\n", buf, readwrite);
 117                 if (readwrite && !probe_event_dry_run)
 118                         ret = open(buf, O_RDWR | O_APPEND, 0);
 119                 else
 120                         ret = open(buf, O_RDONLY, 0);
 121
 122                 if (ret < 0)
 123                         ret = -errno;
 124         }
 125         return ret;
 126 }
 127
 128 static int open_kprobe_events(bool readwrite)
 129 {
 130         return open_trace_file("kprobe_events", readwrite);
 131 }
 132
 133 static int open_uprobe_events(bool readwrite)
 134 {
 135         return open_trace_file("uprobe_events", readwrite);
 136 }
 137
 138 int probe_file__open(int flag)
 139 {
 140         int fd;
 141
 142         if (flag & PF_FL_UPROBE)
 143                 fd = open_uprobe_events(flag & PF_FL_RW);
 144         else
 145                 fd = open_kprobe_events(flag & PF_FL_RW);
 146         if (fd < 0)
 147                 print_open_warning(fd, flag & PF_FL_UPROBE, flag & PF_FL_RW);
 148
 149         return fd;
 150 }
 151
 152 int probe_file__open_both(int *kfd, int *ufd, int flag)
 153 {
 154         if (!kfd || !ufd)
 155                 return -EINVAL;
 156
 157         *kfd = open_kprobe_events(flag & PF_FL_RW);
 158         *ufd = open_uprobe_events(flag & PF_FL_RW);
 159         if (*kfd < 0 && *ufd < 0) {
 160                 print_both_open_warning(*kfd, *ufd, flag & PF_FL_RW);
 161                 return *kfd;
 162         }
 163
 164         return 0;
 165 }
 166
 167 /* Get raw string list of current kprobe_events  or uprobe_events */
 168 struct strlist *probe_file__get_rawlist(int fd)
 169 {
 170         int ret, idx, fddup;
 171         FILE *fp;
 172         char buf[MAX_CMDLEN];
 173         char *p;
 174         struct strlist *sl;
 175
 176         if (fd < 0)
 177                 return NULL;
 178
 179         sl = strlist__new(NULL, NULL);
 180         if (sl == NULL)
 181                 return NULL;
 182
 183         fddup = dup(fd);
 184         if (fddup < 0)
 185                 goto out_free_sl;
 186
 187         fp = fdopen(fddup, "r");
 188         if (!fp)
 189                 goto out_close_fddup;
 190
 191         while (!feof(fp)) {
 192                 p = fgets(buf, MAX_CMDLEN, fp);
 193                 if (!p)
 194                         break;
 195
 196                 idx = strlen(p) - 1;
 197                 if (p[idx] == '\n')
 198                         p[idx] = '\0';
 199                 ret = strlist__add(sl, buf);
 200                 if (ret < 0) {
 201                         pr_debug("strlist__add failed (%d)\n", ret);
 202                         goto out_close_fp;
 203                 }
 204         }
 205         fclose(fp);
 206
 207         return sl;
 208
 209 out_close_fp:
 210         fclose(fp);
 211         goto out_free_sl;
 212 out_close_fddup:
 213         close(fddup);
 214 out_free_sl:
 215         strlist__delete(sl);
 216         return NULL;
 217 }
 218
 219 static struct strlist *__probe_file__get_namelist(int fd, bool include_group)
 220 {
 221         char buf[128];
 222         struct strlist *sl, *rawlist;
 223         struct str_node *ent;
 224         struct probe_trace_event tev;
 225         int ret = 0;
 226
 227         memset(&tev, 0, sizeof(tev));
 228         rawlist = probe_file__get_rawlist(fd);
 229         if (!rawlist)
 230                 return NULL;
 231         sl = strlist__new(NULL, NULL);
 232         strlist__for_each_entry(ent, rawlist) {
 233                 ret = parse_probe_trace_command(ent->s, &tev);
 234                 if (ret < 0)
 235                         break;
 236                 if (include_group) {
 237                         ret = e_snprintf(buf, 128, "%s:%s", tev.group,
 238                                         tev.event);
 239                         if (ret >= 0)
 240                                 ret = strlist__add(sl, buf);
 241                 } else
 242                         ret = strlist__add(sl, tev.event);
 243                 clear_probe_trace_event(&tev);
 244                 /* Skip if there is same name multi-probe event in the list */
 245                 if (ret == -EEXIST)
 246                         ret = 0;
 247                 if (ret < 0)
 248                         break;
 249         }
 250         strlist__delete(rawlist);
 251
 252         if (ret < 0) {
 253                 strlist__delete(sl);
 254                 return NULL;
 255         }
 256         return sl;
 257 }
 258
 259 /* Get current perf-probe event names */
 260 struct strlist *probe_file__get_namelist(int fd)
 261 {
 262         return __probe_file__get_namelist(fd, false);
 263 }
 264
 265 int probe_file__add_event(int fd, struct probe_trace_event *tev)
 266 {
 267         int ret = 0;
 268         char *buf = synthesize_probe_trace_command(tev);
 269         char sbuf[STRERR_BUFSIZE];
 270
 271         if (!buf) {
 272                 pr_debug("Failed to synthesize probe trace event.\n");
 273                 return -EINVAL;
 274         }
 275
 276         pr_debug("Writing event: %s\n", buf);
 277         if (!probe_event_dry_run) {
 278                 if (write(fd, buf, strlen(buf)) < (int)strlen(buf)) {
 279                         ret = -errno;
 280                         pr_warning("Failed to write event: %s\n",
 281                                    str_error_r(errno, sbuf, sizeof(sbuf)));
 282                 }
 283         }
 284         free(buf);
 285
 286         return ret;
 287 }
 288
 289 static int __del_trace_probe_event(int fd, struct str_node *ent)
 290 {
 291         char *p;
 292         char buf[128];
 293         int ret;
 294
 295         /* Convert from perf-probe event to trace-probe event */
 296         ret = e_snprintf(buf, 128, "-:%s", ent->s);
 297         if (ret < 0)
 298                 goto error;
 299
 300         p = strchr(buf + 2, ':');
 301         if (!p) {
 302                 pr_debug("Internal error: %s should have ':' but not.\n",
 303                          ent->s);
 304                 ret = -ENOTSUP;
 305                 goto error;
 306         }
 307         *p = '/';
 308
 309         pr_debug("Writing event: %s\n", buf);
 310         ret = write(fd, buf, strlen(buf));
 311         if (ret < 0) {
 312                 ret = -errno;
 313                 goto error;
 314         }
 315
 316         return 0;
 317 error:
 318         pr_warning("Failed to delete event: %s\n",
 319                    str_error_r(-ret, buf, sizeof(buf)));
 320         return ret;
 321 }
 322
 323 int probe_file__get_events(int fd, struct strfilter *filter,
 324                            struct strlist *plist)
 325 {
 326         struct strlist *namelist;
 327         struct str_node *ent;
 328         const char *p;
 329         int ret = -ENOENT;
 330
 331         if (!plist)
 332                 return -EINVAL;
 333
 334         namelist = __probe_file__get_namelist(fd, true);
 335         if (!namelist)
 336                 return -ENOENT;
 337
 338         strlist__for_each_entry(ent, namelist) {
 339                 p = strchr(ent->s, ':');
 340                 if ((p && strfilter__compare(filter, p + 1)) ||
 341                     strfilter__compare(filter, ent->s)) {
 342                         ret = strlist__add(plist, ent->s);
 343                         if (ret == -ENOMEM) {
 344                                 pr_err("strlist__add failed with -ENOMEM\n");
 345                                 goto out;
 346                         }
 347                         ret = 0;
 348                 }
 349         }
 350 out:
 351         strlist__delete(namelist);
 352
 353         return ret;
 354 }
 355
 356 int probe_file__del_strlist(int fd, struct strlist *namelist)
 357 {
 358         int ret = 0;
 359         struct str_node *ent;
 360
 361         strlist__for_each_entry(ent, namelist) {
 362                 ret = __del_trace_probe_event(fd, ent);
 363                 if (ret < 0)
 364                         break;
 365         }
 366         return ret;
 367 }
 368
 369 /* Caller must ensure to remove this entry from list */
 370 static void probe_cache_entry__delete(struct probe_cache_entry *entry)
 371 {
 372         if (entry) {
 373                 BUG_ON(!list_empty(&entry->node));
 374
 375                 strlist__delete(entry->tevlist);
 376                 clear_perf_probe_event(&entry->pev);
 377                 zfree(&entry->spev);
 378                 free(entry);
 379         }
 380 }
 381
 382 static struct probe_cache_entry *
 383 probe_cache_entry__new(struct perf_probe_event *pev)
 384 {
 385         struct probe_cache_entry *entry = zalloc(sizeof(*entry));
 386
 387         if (entry) {
 388                 INIT_LIST_HEAD(&entry->node);
 389                 entry->tevlist = strlist__new(NULL, NULL);
 390                 if (!entry->tevlist)
 391                         zfree(&entry);
 392                 else if (pev) {
 393                         entry->spev = synthesize_perf_probe_command(pev);
 394                         if (!entry->spev ||
 395                             perf_probe_event__copy(&entry->pev, pev) < 0) {
 396                                 probe_cache_entry__delete(entry);
 397                                 return NULL;
 398                         }
 399                 }
 400         }
 401
 402         return entry;
 403 }
 404
 405 int probe_cache_entry__get_event(struct probe_cache_entry *entry,
 406                                  struct probe_trace_event **tevs)
 407 {
 408         struct probe_trace_event *tev;
 409         struct str_node *node;
 410         int ret, i;
 411
 412         ret = strlist__nr_entries(entry->tevlist);
 413         if (ret > probe_conf.max_probes)
 414                 return -E2BIG;
 415
 416         *tevs = zalloc(ret * sizeof(*tev));
 417         if (!*tevs)
 418                 return -ENOMEM;
 419
 420         i = 0;
 421         strlist__for_each_entry(node, entry->tevlist) {
 422                 tev = &(*tevs)[i++];
 423                 ret = parse_probe_trace_command(node->s, tev);
 424                 if (ret < 0)
 425                         break;
 426         }
 427         return i;
 428 }
 429
 430 /* For the kernel probe caches, pass target = NULL or DSO__NAME_KALLSYMS */
 431 static int probe_cache__open(struct probe_cache *pcache, const char *target,
 432                              struct nsinfo *nsi)
 433 {
 434         char cpath[PATH_MAX];
 435         char sbuildid[SBUILD_ID_SIZE];
 436         char *dir_name = NULL;
 437         bool is_kallsyms = false;
 438         int ret, fd;
 439         struct nscookie nsc;
 440
 441         if (target && build_id_cache__cached(target)) {
 442                 /* This is a cached buildid */
 443                 strlcpy(sbuildid, target, SBUILD_ID_SIZE);
 444                 dir_name = build_id_cache__linkname(sbuildid, NULL, 0);
 445                 goto found;
 446         }
 447
 448         if (!target || !strcmp(target, DSO__NAME_KALLSYMS)) {
 449                 target = DSO__NAME_KALLSYMS;
 450                 is_kallsyms = true;
 451                 ret = sysfs__sprintf_build_id("/", sbuildid);
 452         } else {
 453                 nsinfo__mountns_enter(nsi, &nsc);
 454                 ret = filename__sprintf_build_id(target, sbuildid);
 455                 nsinfo__mountns_exit(&nsc);
 456         }
 457
 458         if (ret < 0) {
 459                 pr_debug("Failed to get build-id from %s.\n", target);
 460                 return ret;
 461         }
 462
 463         /* If we have no buildid cache, make it */
 464         if (!build_id_cache__cached(sbuildid)) {
 465                 ret = build_id_cache__add_s(sbuildid, target, nsi,
 466                                             is_kallsyms, NULL);
 467                 if (ret < 0) {
 468                         pr_debug("Failed to add build-id cache: %s\n", target);
 469                         return ret;
 470                 }
 471         }
 472
 473         dir_name = build_id_cache__cachedir(sbuildid, target, nsi, is_kallsyms,
 474                                             false);
 475 found:
 476         if (!dir_name) {
 477                 pr_debug("Failed to get cache from %s\n", target);
 478                 return -ENOMEM;
 479         }
 480
 481         snprintf(cpath, PATH_MAX, "%s/probes", dir_name);
 482         fd = open(cpath, O_CREAT | O_RDWR, 0644);
 483         if (fd < 0)
 484                 pr_debug("Failed to open cache(%d): %s\n", fd, cpath);
 485         free(dir_name);
 486         pcache->fd = fd;
 487
 488         return fd;
 489 }
 490
 491 static int probe_cache__load(struct probe_cache *pcache)
 492 {
 493         struct probe_cache_entry *entry = NULL;
 494         char buf[MAX_CMDLEN], *p;
 495         int ret = 0, fddup;
 496         FILE *fp;
 497
 498         fddup = dup(pcache->fd);
 499         if (fddup < 0)
 500                 return -errno;
 501         fp = fdopen(fddup, "r");
 502         if (!fp) {
 503                 close(fddup);
 504                 return -EINVAL;
 505         }
 506
 507         while (!feof(fp)) {
 508                 if (!fgets(buf, MAX_CMDLEN, fp))
 509                         break;
 510                 p = strchr(buf, '\n');
 511                 if (p)
 512                         *p = '\0';
 513                 /* #perf_probe_event or %sdt_event */
 514                 if (buf[0] == '#' || buf[0] == '%') {
 515                         entry = probe_cache_entry__new(NULL);
 516                         if (!entry) {
 517                                 ret = -ENOMEM;
 518                                 goto out;
 519                         }
 520                         if (buf[0] == '%')
 521                                 entry->sdt = true;
 522                         entry->spev = strdup(buf + 1);
 523                         if (entry->spev)
 524                                 ret = parse_perf_probe_command(buf + 1,
 525                                                                 &entry->pev);
 526                         else
 527                                 ret = -ENOMEM;
 528                         if (ret < 0) {
 529                                 probe_cache_entry__delete(entry);
 530                                 goto out;
 531                         }
 532                         list_add_tail(&entry->node, &pcache->entries);
 533                 } else {        /* trace_probe_event */
 534                         if (!entry) {
 535                                 ret = -EINVAL;
 536                                 goto out;
 537                         }
 538                         ret = strlist__add(entry->tevlist, buf);
 539                         if (ret == -ENOMEM) {
 540                                 pr_err("strlist__add failed with -ENOMEM\n");
 541                                 goto out;
 542                         }
 543                 }
 544         }
 545 out:
 546         fclose(fp);
 547         return ret;
 548 }
 549
 550 static struct probe_cache *probe_cache__alloc(void)
 551 {
 552         struct probe_cache *pcache = zalloc(sizeof(*pcache));
 553
 554         if (pcache) {
 555                 INIT_LIST_HEAD(&pcache->entries);
 556                 pcache->fd = -EINVAL;
 557         }
 558         return pcache;
 559 }
 560
 561 void probe_cache__purge(struct probe_cache *pcache)
 562 {
 563         struct probe_cache_entry *entry, *n;
 564
 565         list_for_each_entry_safe(entry, n, &pcache->entries, node) {
 566                 list_del_init(&entry->node);
 567                 probe_cache_entry__delete(entry);
 568         }
 569 }
 570
 571 void probe_cache__delete(struct probe_cache *pcache)
 572 {
 573         if (!pcache)
 574                 return;
 575
 576         probe_cache__purge(pcache);
 577         if (pcache->fd > 0)
 578                 close(pcache->fd);
 579         free(pcache);
 580 }
 581
 582 struct probe_cache *probe_cache__new(const char *target, struct nsinfo *nsi)
 583 {
 584         struct probe_cache *pcache = probe_cache__alloc();
 585         int ret;
 586
 587         if (!pcache)
 588                 return NULL;
 589
 590         ret = probe_cache__open(pcache, target, nsi);
 591         if (ret < 0) {
 592                 pr_debug("Cache open error: %d\n", ret);
 593                 goto out_err;
 594         }
 595
 596         ret = probe_cache__load(pcache);
 597         if (ret < 0) {
 598                 pr_debug("Cache read error: %d\n", ret);
 599                 goto out_err;
 600         }
 601
 602         return pcache;
 603
 604 out_err:
 605         probe_cache__delete(pcache);
 606         return NULL;
 607 }
 608
 609 static bool streql(const char *a, const char *b)
 610 {
 611         if (a == b)
 612                 return true;
 613
 614         if (!a || !b)
 615                 return false;
 616
 617         return !strcmp(a, b);
 618 }
 619
 620 struct probe_cache_entry *
 621 probe_cache__find(struct probe_cache *pcache, struct perf_probe_event *pev)
 622 {
 623         struct probe_cache_entry *entry = NULL;
 624         char *cmd = synthesize_perf_probe_command(pev);
 625
 626         if (!cmd)
 627                 return NULL;
 628
 629         for_each_probe_cache_entry(entry, pcache) {
 630                 if (pev->sdt) {
 631                         if (entry->pev.event &&
 632                             streql(entry->pev.event, pev->event) &&
 633                             (!pev->group ||
 634                              streql(entry->pev.group, pev->group)))
 635                                 goto found;
 636
 637                         continue;
 638                 }
 639                 /* Hit if same event name or same command-string */
 640                 if ((pev->event &&
 641                      (streql(entry->pev.group, pev->group) &&
 642                       streql(entry->pev.event, pev->event))) ||
 643                     (!strcmp(entry->spev, cmd)))
 644                         goto found;
 645         }
 646         entry = NULL;
 647
 648 found:
 649         free(cmd);
 650         return entry;
 651 }
 652
 653 struct probe_cache_entry *
 654 probe_cache__find_by_name(struct probe_cache *pcache,
 655                           const char *group, const char *event)
 656 {
 657         struct probe_cache_entry *entry = NULL;
 658
 659         for_each_probe_cache_entry(entry, pcache) {
 660                 /* Hit if same event name or same command-string */
 661                 if (streql(entry->pev.group, group) &&
 662                     streql(entry->pev.event, event))
 663                         goto found;
 664         }
 665         entry = NULL;
 666
 667 found:
 668         return entry;
 669 }
 670
 671 int probe_cache__add_entry(struct probe_cache *pcache,
 672                            struct perf_probe_event *pev,
 673                            struct probe_trace_event *tevs, int ntevs)
 674 {
 675         struct probe_cache_entry *entry = NULL;
 676         char *command;
 677         int i, ret = 0;
 678
 679         if (!pcache || !pev || !tevs || ntevs <= 0) {
 680                 ret = -EINVAL;
 681                 goto out_err;
 682         }
 683
 684         /* Remove old cache entry */
 685         entry = probe_cache__find(pcache, pev);
 686         if (entry) {
 687                 list_del_init(&entry->node);
 688                 probe_cache_entry__delete(entry);
 689         }
 690
 691         ret = -ENOMEM;
 692         entry = probe_cache_entry__new(pev);
 693         if (!entry)
 694                 goto out_err;
 695
 696         for (i = 0; i < ntevs; i++) {
 697                 if (!tevs[i].point.symbol)
 698                         continue;
 699
 700                 command = synthesize_probe_trace_command(&tevs[i]);
 701                 if (!command)
 702                         goto out_err;
 703                 ret = strlist__add(entry->tevlist, command);
 704                 if (ret == -ENOMEM) {
 705                         pr_err("strlist__add failed with -ENOMEM\n");
 706                         goto out_err;
 707                 }
 708
 709                 free(command);
 710         }
 711         list_add_tail(&entry->node, &pcache->entries);
 712         pr_debug("Added probe cache: %d\n", ntevs);
 713         return 0;
 714
 715 out_err:
 716         pr_debug("Failed to add probe caches\n");
 717         probe_cache_entry__delete(entry);
 718         return ret;
 719 }
 720
 721 #ifdef HAVE_GELF_GETNOTE_SUPPORT
 722 static unsigned long long sdt_note__get_addr(struct sdt_note *note)
 723 {
 724         return note->bit32 ?
 725                 (unsigned long long)note->addr.a32[SDT_NOTE_IDX_LOC] :
 726                 (unsigned long long)note->addr.a64[SDT_NOTE_IDX_LOC];
 727 }
 728
 729 static unsigned long long sdt_note__get_ref_ctr_offset(struct sdt_note *note)
 730 {
 731         return note->bit32 ?
 732                 (unsigned long long)note->addr.a32[SDT_NOTE_IDX_REFCTR] :
 733                 (unsigned long long)note->addr.a64[SDT_NOTE_IDX_REFCTR];
 734 }
 735
 736 static const char * const type_to_suffix[] = {
 737         ":s64", "", "", "", ":s32", "", ":s16", ":s8",
 738         "", ":u8", ":u16", "", ":u32", "", "", "", ":u64"
 739 };
 740
 741 /*
 742  * Isolate the string number and convert it into a decimal value;
 743  * this will be an index to get suffix of the uprobe name (defining
 744  * the type)
 745  */
 746 static int sdt_arg_parse_size(char *n_ptr, const char **suffix)
 747 {
 748         long type_idx;
 749
 750         type_idx = strtol(n_ptr, NULL, 10);
 751         if (type_idx < -8 || type_idx > 8) {
 752                 pr_debug4("Failed to get a valid sdt type\n");
 753                 return -1;
 754         }
 755
 756         *suffix = type_to_suffix[type_idx + 8];
 757         return 0;
 758 }
 759
 760 static int synthesize_sdt_probe_arg(struct strbuf *buf, int i, const char *arg)
 761 {
 762         char *op, *desc = strdup(arg), *new_op = NULL;
 763         const char *suffix = "";
 764         int ret = -1;
 765
 766         if (desc == NULL) {
 767                 pr_debug4("Allocation error\n");
 768                 return ret;
 769         }
 770
 771         /*
 772          * Argument is in N@OP format. N is size of the argument and OP is
 773          * the actual assembly operand. N can be omitted; in that case
 774          * argument is just OP(without @).
 775          */
 776         op = strchr(desc, '@');
 777         if (op) {
 778                 op[0] = '\0';
 779                 op++;
 780
 781                 if (sdt_arg_parse_size(desc, &suffix))
 782                         goto error;
 783         } else {
 784                 op = desc;
 785         }
 786
 787         ret = arch_sdt_arg_parse_op(op, &new_op);
 788
 789         if (ret < 0)
 790                 goto error;
 791
 792         if (ret == SDT_ARG_VALID) {
 793                 ret = strbuf_addf(buf, " arg%d=%s%s", i + 1, new_op, suffix);
 794                 if (ret < 0)
 795                         goto error;
 796         }
 797
 798         ret = 0;
 799 error:
 800         free(desc);
 801         free(new_op);
 802         return ret;
 803 }
 804
 805 static char *synthesize_sdt_probe_command(struct sdt_note *note,
 806                                         const char *pathname,
 807                                         const char *sdtgrp)
 808 {
 809         struct strbuf buf;
 810         char *ret = NULL;
 811         int i, args_count, err;
 812         unsigned long long ref_ctr_offset;
 813         char *arg;
 814         int arg_idx = 0;
 815
 816         if (strbuf_init(&buf, 32) < 0)
 817                 return NULL;
 818
 819         err = strbuf_addf(&buf, "p:%s/%s %s:0x%llx",
 820                         sdtgrp, note->name, pathname,
 821                         sdt_note__get_addr(note));
 822
 823         ref_ctr_offset = sdt_note__get_ref_ctr_offset(note);
 824         if (ref_ctr_offset && err >= 0)
 825                 err = strbuf_addf(&buf, "(0x%llx)", ref_ctr_offset);
 826
 827         if (err < 0)
 828                 goto error;
 829
 830         if (!note->args)
 831                 goto out;
 832
 833         if (note->args) {
 834                 char **args = argv_split(note->args, &args_count);
 835
 836                 if (args == NULL)
 837                         goto error;
 838
 839                 for (i = 0; i < args_count; ) {
 840                         /*
 841                          * FIXUP: Arm64 ELF section '.note.stapsdt' uses string
 842                          * format "-4@[sp, NUM]" if a probe is to access data in
 843                          * the stack, e.g. below is an example for the SDT
 844                          * Arguments:
 845                          *
 846                          *   Arguments: -4@[sp, 12] -4@[sp, 8] -4@[sp, 4]
 847                          *
 848                          * Since the string introduces an extra space character
 849                          * in the middle of square brackets, the argument is
 850                          * divided into two items.  Fixup for this case, if an
 851                          * item contains sub string "[sp,", need to concatenate
 852                          * the two items.
 853                          */
 854                         if (strstr(args[i], "[sp,") && (i+1) < args_count) {
 855                                 err = asprintf(&arg, "%s %s", args[i], args[i+1]);
 856                                 i += 2;
 857                         } else {
 858                                 err = asprintf(&arg, "%s", args[i]);
 859                                 i += 1;
 860                         }
 861
 862                         /* Failed to allocate memory */
 863                         if (err < 0) {
 864                                 argv_free(args);
 865                                 goto error;
 866                         }
 867
 868                         if (synthesize_sdt_probe_arg(&buf, arg_idx, arg) < 0) {
 869                                 free(arg);
 870                                 argv_free(args);
 871                                 goto error;
 872                         }
 873
 874                         free(arg);
 875                         arg_idx++;
 876                 }
 877
 878                 argv_free(args);
 879         }
 880
 881 out:
 882         ret = strbuf_detach(&buf, NULL);
 883 error:
 884         strbuf_release(&buf);
 885         return ret;
 886 }
 887
 888 int probe_cache__scan_sdt(struct probe_cache *pcache, const char *pathname)
 889 {
 890         struct probe_cache_entry *entry = NULL;
 891         struct list_head sdtlist;
 892         struct sdt_note *note;
 893         char *buf;
 894         char sdtgrp[64];
 895         int ret;
 896
 897         INIT_LIST_HEAD(&sdtlist);
 898         ret = get_sdt_note_list(&sdtlist, pathname);
 899         if (ret < 0) {
 900                 pr_debug4("Failed to get sdt note: %d\n", ret);
 901                 return ret;
 902         }
 903         list_for_each_entry(note, &sdtlist, note_list) {
 904                 ret = snprintf(sdtgrp, 64, "sdt_%s", note->provider);
 905                 if (ret < 0)
 906                         break;
 907                 /* Try to find same-name entry */
 908                 entry = probe_cache__find_by_name(pcache, sdtgrp, note->name);
 909                 if (!entry) {
 910                         entry = probe_cache_entry__new(NULL);
 911                         if (!entry) {
 912                                 ret = -ENOMEM;
 913                                 break;
 914                         }
 915                         entry->sdt = true;
 916                         ret = asprintf(&entry->spev, "%s:%s=%s", sdtgrp,
 917                                         note->name, note->name);
 918                         if (ret < 0)
 919                                 break;
 920                         entry->pev.event = strdup(note->name);
 921                         entry->pev.group = strdup(sdtgrp);
 922                         list_add_tail(&entry->node, &pcache->entries);
 923                 }
 924                 buf = synthesize_sdt_probe_command(note, pathname, sdtgrp);
 925                 if (!buf) {
 926                         ret = -ENOMEM;
 927                         break;
 928                 }
 929
 930                 ret = strlist__add(entry->tevlist, buf);
 931
 932                 free(buf);
 933                 entry = NULL;
 934
 935                 if (ret == -ENOMEM) {
 936                         pr_err("strlist__add failed with -ENOMEM\n");
 937                         break;
 938                 }
 939         }
 940         if (entry) {
 941                 list_del_init(&entry->node);
 942                 probe_cache_entry__delete(entry);
 943         }
 944         cleanup_sdt_note_list(&sdtlist);
 945         return ret;
 946 }
 947 #endif
 948
 949 static int probe_cache_entry__write(struct probe_cache_entry *entry, int fd)
 950 {
 951         struct str_node *snode;
 952         struct stat st;
 953         struct iovec iov[3];
 954         const char *prefix = entry->sdt ? "%" : "#";
 955         int ret;
 956         /* Save stat for rollback */
 957         ret = fstat(fd, &st);
 958         if (ret < 0)
 959                 return ret;
 960
 961         pr_debug("Writing cache: %s%s\n", prefix, entry->spev);
 962         iov[0].iov_base = (void *)prefix; iov[0].iov_len = 1;
 963         iov[1].iov_base = entry->spev; iov[1].iov_len = strlen(entry->spev);
 964         iov[2].iov_base = (void *)"\n"; iov[2].iov_len = 1;
 965         ret = writev(fd, iov, 3);
 966         if (ret < (int)iov[1].iov_len + 2)
 967                 goto rollback;
 968
 969         strlist__for_each_entry(snode, entry->tevlist) {
 970                 iov[0].iov_base = (void *)snode->s;
 971                 iov[0].iov_len = strlen(snode->s);
 972                 iov[1].iov_base = (void *)"\n"; iov[1].iov_len = 1;
 973                 ret = writev(fd, iov, 2);
 974                 if (ret < (int)iov[0].iov_len + 1)
 975                         goto rollback;
 976         }
 977         return 0;
 978
 979 rollback:
 980         /* Rollback to avoid cache file corruption */
 981         if (ret > 0)
 982                 ret = -1;
 983         if (ftruncate(fd, st.st_size) < 0)
 984                 ret = -2;
 985
 986         return ret;
 987 }
 988
 989 int probe_cache__commit(struct probe_cache *pcache)
 990 {
 991         struct probe_cache_entry *entry;
 992         int ret = 0;
 993
 994         /* TBD: if we do not update existing entries, skip it */
 995         ret = lseek(pcache->fd, 0, SEEK_SET);
 996         if (ret < 0)
 997                 goto out;
 998
 999         ret = ftruncate(pcache->fd, 0);
1000         if (ret < 0)
1001                 goto out;
1002
1003         for_each_probe_cache_entry(entry, pcache) {
1004                 ret = probe_cache_entry__write(entry, pcache->fd);
1005                 pr_debug("Cache committed: %d\n", ret);
1006                 if (ret < 0)
1007                         break;
1008         }
1009 out:
1010         return ret;
1011 }
1012
1013 static bool probe_cache_entry__compare(struct probe_cache_entry *entry,
1014                                        struct strfilter *filter)
1015 {
1016         char buf[128], *ptr = entry->spev;
1017
1018         if (entry->pev.event) {
1019                 snprintf(buf, 128, "%s:%s", entry->pev.group, entry->pev.event);
1020                 ptr = buf;
1021         }
1022         return strfilter__compare(filter, ptr);
1023 }
1024
1025 int probe_cache__filter_purge(struct probe_cache *pcache,
1026                               struct strfilter *filter)
1027 {
1028         struct probe_cache_entry *entry, *tmp;
1029
1030         list_for_each_entry_safe(entry, tmp, &pcache->entries, node) {
1031                 if (probe_cache_entry__compare(entry, filter)) {
1032                         pr_info("Removed cached event: %s\n", entry->spev);
1033                         list_del_init(&entry->node);
1034                         probe_cache_entry__delete(entry);
1035                 }
1036         }
1037         return 0;
1038 }
1039
1040 static int probe_cache__show_entries(struct probe_cache *pcache,
1041                                      struct strfilter *filter)
1042 {
1043         struct probe_cache_entry *entry;
1044
1045         for_each_probe_cache_entry(entry, pcache) {
1046                 if (probe_cache_entry__compare(entry, filter))
1047                         printf("%s\n", entry->spev);
1048         }
1049         return 0;
1050 }
1051
1052 /* Show all cached probes */
1053 int probe_cache__show_all_caches(struct strfilter *filter)
1054 {
1055         struct probe_cache *pcache;
1056         struct strlist *bidlist;
1057         struct str_node *nd;
1058         char *buf = strfilter__string(filter);
1059
1060         pr_debug("list cache with filter: %s\n", buf);
1061         free(buf);
1062
1063         bidlist = build_id_cache__list_all(true);
1064         if (!bidlist) {
1065                 pr_debug("Failed to get buildids: %d\n", errno);
1066                 return -EINVAL;
1067         }
1068         strlist__for_each_entry(nd, bidlist) {
1069                 pcache = probe_cache__new(nd->s, NULL);
1070                 if (!pcache)
1071                         continue;
1072                 if (!list_empty(&pcache->entries)) {
1073                         buf = build_id_cache__origname(nd->s);
1074                         printf("%s (%s):\n", buf, nd->s);
1075                         free(buf);
1076                         probe_cache__show_entries(pcache, filter);
1077                 }
1078                 probe_cache__delete(pcache);
1079         }
1080         strlist__delete(bidlist);
1081
1082         return 0;
1083 }
1084
1085 enum ftrace_readme {
1086         FTRACE_README_PROBE_TYPE_X = 0,
1087         FTRACE_README_KRETPROBE_OFFSET,
1088         FTRACE_README_UPROBE_REF_CTR,
1089         FTRACE_README_USER_ACCESS,
1090         FTRACE_README_MULTIPROBE_EVENT,
1091         FTRACE_README_IMMEDIATE_VALUE,
1092         FTRACE_README_END,
1093 };
1094
1095 static struct {
1096         const char *pattern;
1097         bool avail;
1098 } ftrace_readme_table[] = {
1099 #define DEFINE_TYPE(idx, pat)                   \
1100         [idx] = {.pattern = pat, .avail = false}
1101         DEFINE_TYPE(FTRACE_README_PROBE_TYPE_X, "*type: * x8/16/32/64,*"),
1102         DEFINE_TYPE(FTRACE_README_KRETPROBE_OFFSET, "*place (kretprobe): *"),
1103         DEFINE_TYPE(FTRACE_README_UPROBE_REF_CTR, "*ref_ctr_offset*"),
1104         DEFINE_TYPE(FTRACE_README_USER_ACCESS, "*u]<offset>*"),
1105         DEFINE_TYPE(FTRACE_README_MULTIPROBE_EVENT, "*Create/append/*"),
1106         DEFINE_TYPE(FTRACE_README_IMMEDIATE_VALUE, "*\\imm-value,*"),
1107 };
1108
1109 static bool scan_ftrace_readme(enum ftrace_readme type)
1110 {
1111         int fd;
1112         FILE *fp;
1113         char *buf = NULL;
1114         size_t len = 0;
1115         bool ret = false;
1116         static bool scanned = false;
1117
1118         if (scanned)
1119                 goto result;
1120
1121         fd = open_trace_file("README", false);
1122         if (fd < 0)
1123                 return ret;
1124
1125         fp = fdopen(fd, "r");
1126         if (!fp) {
1127                 close(fd);
1128                 return ret;
1129         }
1130
1131         while (getline(&buf, &len, fp) > 0)
1132                 for (enum ftrace_readme i = 0; i < FTRACE_README_END; i++)
1133                         if (!ftrace_readme_table[i].avail)
1134                                 ftrace_readme_table[i].avail =
1135                                         strglobmatch(buf, ftrace_readme_table[i].pattern);
1136         scanned = true;
1137
1138         fclose(fp);
1139         free(buf);
1140
1141 result:
1142         if (type >= FTRACE_README_END)
1143                 return false;
1144
1145         return ftrace_readme_table[type].avail;
1146 }
1147
1148 bool probe_type_is_available(enum probe_type type)
1149 {
1150         if (type >= PROBE_TYPE_END)
1151                 return false;
1152         else if (type == PROBE_TYPE_X)
1153                 return scan_ftrace_readme(FTRACE_README_PROBE_TYPE_X);
1154
1155         return true;
1156 }
1157
1158 bool kretprobe_offset_is_supported(void)
1159 {
1160         return scan_ftrace_readme(FTRACE_README_KRETPROBE_OFFSET);
1161 }
1162
1163 bool uprobe_ref_ctr_is_supported(void)
1164 {
1165         return scan_ftrace_readme(FTRACE_README_UPROBE_REF_CTR);
1166 }
1167
1168 bool user_access_is_supported(void)
1169 {
1170         return scan_ftrace_readme(FTRACE_README_USER_ACCESS);
1171 }
1172
1173 bool multiprobe_event_is_supported(void)
1174 {
1175         return scan_ftrace_readme(FTRACE_README_MULTIPROBE_EVENT);
1176 }
1177
1178 bool immediate_value_is_supported(void)
1179 {
1180         return scan_ftrace_readme(FTRACE_README_IMMEDIATE_VALUE);
1181 }