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 int probe_file__del_events(int fd, struct strfilter *filter)
 370 {
 371         struct strlist *namelist;
 372         int ret;
 373
 374         namelist = strlist__new(NULL, NULL);
 375         if (!namelist)
 376                 return -ENOMEM;
 377
 378         ret = probe_file__get_events(fd, filter, namelist);
 379         if (ret < 0)
 380                 return ret;
 381
 382         ret = probe_file__del_strlist(fd, namelist);
 383         strlist__delete(namelist);
 384
 385         return ret;
 386 }
 387
 388 /* Caller must ensure to remove this entry from list */
 389 static void probe_cache_entry__delete(struct probe_cache_entry *entry)
 390 {
 391         if (entry) {
 392                 BUG_ON(!list_empty(&entry->node));
 393
 394                 strlist__delete(entry->tevlist);
 395                 clear_perf_probe_event(&entry->pev);
 396                 zfree(&entry->spev);
 397                 free(entry);
 398         }
 399 }
 400
 401 static struct probe_cache_entry *
 402 probe_cache_entry__new(struct perf_probe_event *pev)
 403 {
 404         struct probe_cache_entry *entry = zalloc(sizeof(*entry));
 405
 406         if (entry) {
 407                 INIT_LIST_HEAD(&entry->node);
 408                 entry->tevlist = strlist__new(NULL, NULL);
 409                 if (!entry->tevlist)
 410                         zfree(&entry);
 411                 else if (pev) {
 412                         entry->spev = synthesize_perf_probe_command(pev);
 413                         if (!entry->spev ||
 414                             perf_probe_event__copy(&entry->pev, pev) < 0) {
 415                                 probe_cache_entry__delete(entry);
 416                                 return NULL;
 417                         }
 418                 }
 419         }
 420
 421         return entry;
 422 }
 423
 424 int probe_cache_entry__get_event(struct probe_cache_entry *entry,
 425                                  struct probe_trace_event **tevs)
 426 {
 427         struct probe_trace_event *tev;
 428         struct str_node *node;
 429         int ret, i;
 430
 431         ret = strlist__nr_entries(entry->tevlist);
 432         if (ret > probe_conf.max_probes)
 433                 return -E2BIG;
 434
 435         *tevs = zalloc(ret * sizeof(*tev));
 436         if (!*tevs)
 437                 return -ENOMEM;
 438
 439         i = 0;
 440         strlist__for_each_entry(node, entry->tevlist) {
 441                 tev = &(*tevs)[i++];
 442                 ret = parse_probe_trace_command(node->s, tev);
 443                 if (ret < 0)
 444                         break;
 445         }
 446         return i;
 447 }
 448
 449 /* For the kernel probe caches, pass target = NULL or DSO__NAME_KALLSYMS */
 450 static int probe_cache__open(struct probe_cache *pcache, const char *target,
 451                              struct nsinfo *nsi)
 452 {
 453         char cpath[PATH_MAX];
 454         char sbuildid[SBUILD_ID_SIZE];
 455         char *dir_name = NULL;
 456         bool is_kallsyms = false;
 457         int ret, fd;
 458         struct nscookie nsc;
 459
 460         if (target && build_id_cache__cached(target)) {
 461                 /* This is a cached buildid */
 462                 strlcpy(sbuildid, target, SBUILD_ID_SIZE);
 463                 dir_name = build_id_cache__linkname(sbuildid, NULL, 0);
 464                 goto found;
 465         }
 466
 467         if (!target || !strcmp(target, DSO__NAME_KALLSYMS)) {
 468                 target = DSO__NAME_KALLSYMS;
 469                 is_kallsyms = true;
 470                 ret = sysfs__sprintf_build_id("/", sbuildid);
 471         } else {
 472                 nsinfo__mountns_enter(nsi, &nsc);
 473                 ret = filename__sprintf_build_id(target, sbuildid);
 474                 nsinfo__mountns_exit(&nsc);
 475         }
 476
 477         if (ret < 0) {
 478                 pr_debug("Failed to get build-id from %s.\n", target);
 479                 return ret;
 480         }
 481
 482         /* If we have no buildid cache, make it */
 483         if (!build_id_cache__cached(sbuildid)) {
 484                 ret = build_id_cache__add_s(sbuildid, target, nsi,
 485                                             is_kallsyms, NULL);
 486                 if (ret < 0) {
 487                         pr_debug("Failed to add build-id cache: %s\n", target);
 488                         return ret;
 489                 }
 490         }
 491
 492         dir_name = build_id_cache__cachedir(sbuildid, target, nsi, is_kallsyms,
 493                                             false);
 494 found:
 495         if (!dir_name) {
 496                 pr_debug("Failed to get cache from %s\n", target);
 497                 return -ENOMEM;
 498         }
 499
 500         snprintf(cpath, PATH_MAX, "%s/probes", dir_name);
 501         fd = open(cpath, O_CREAT | O_RDWR, 0644);
 502         if (fd < 0)
 503                 pr_debug("Failed to open cache(%d): %s\n", fd, cpath);
 504         free(dir_name);
 505         pcache->fd = fd;
 506
 507         return fd;
 508 }
 509
 510 static int probe_cache__load(struct probe_cache *pcache)
 511 {
 512         struct probe_cache_entry *entry = NULL;
 513         char buf[MAX_CMDLEN], *p;
 514         int ret = 0, fddup;
 515         FILE *fp;
 516
 517         fddup = dup(pcache->fd);
 518         if (fddup < 0)
 519                 return -errno;
 520         fp = fdopen(fddup, "r");
 521         if (!fp) {
 522                 close(fddup);
 523                 return -EINVAL;
 524         }
 525
 526         while (!feof(fp)) {
 527                 if (!fgets(buf, MAX_CMDLEN, fp))
 528                         break;
 529                 p = strchr(buf, '\n');
 530                 if (p)
 531                         *p = '\0';
 532                 /* #perf_probe_event or %sdt_event */
 533                 if (buf[0] == '#' || buf[0] == '%') {
 534                         entry = probe_cache_entry__new(NULL);
 535                         if (!entry) {
 536                                 ret = -ENOMEM;
 537                                 goto out;
 538                         }
 539                         if (buf[0] == '%')
 540                                 entry->sdt = true;
 541                         entry->spev = strdup(buf + 1);
 542                         if (entry->spev)
 543                                 ret = parse_perf_probe_command(buf + 1,
 544                                                                 &entry->pev);
 545                         else
 546                                 ret = -ENOMEM;
 547                         if (ret < 0) {
 548                                 probe_cache_entry__delete(entry);
 549                                 goto out;
 550                         }
 551                         list_add_tail(&entry->node, &pcache->entries);
 552                 } else {        /* trace_probe_event */
 553                         if (!entry) {
 554                                 ret = -EINVAL;
 555                                 goto out;
 556                         }
 557                         ret = strlist__add(entry->tevlist, buf);
 558                         if (ret == -ENOMEM) {
 559                                 pr_err("strlist__add failed with -ENOMEM\n");
 560                                 goto out;
 561                         }
 562                 }
 563         }
 564 out:
 565         fclose(fp);
 566         return ret;
 567 }
 568
 569 static struct probe_cache *probe_cache__alloc(void)
 570 {
 571         struct probe_cache *pcache = zalloc(sizeof(*pcache));
 572
 573         if (pcache) {
 574                 INIT_LIST_HEAD(&pcache->entries);
 575                 pcache->fd = -EINVAL;
 576         }
 577         return pcache;
 578 }
 579
 580 void probe_cache__purge(struct probe_cache *pcache)
 581 {
 582         struct probe_cache_entry *entry, *n;
 583
 584         list_for_each_entry_safe(entry, n, &pcache->entries, node) {
 585                 list_del_init(&entry->node);
 586                 probe_cache_entry__delete(entry);
 587         }
 588 }
 589
 590 void probe_cache__delete(struct probe_cache *pcache)
 591 {
 592         if (!pcache)
 593                 return;
 594
 595         probe_cache__purge(pcache);
 596         if (pcache->fd > 0)
 597                 close(pcache->fd);
 598         free(pcache);
 599 }
 600
 601 struct probe_cache *probe_cache__new(const char *target, struct nsinfo *nsi)
 602 {
 603         struct probe_cache *pcache = probe_cache__alloc();
 604         int ret;
 605
 606         if (!pcache)
 607                 return NULL;
 608
 609         ret = probe_cache__open(pcache, target, nsi);
 610         if (ret < 0) {
 611                 pr_debug("Cache open error: %d\n", ret);
 612                 goto out_err;
 613         }
 614
 615         ret = probe_cache__load(pcache);
 616         if (ret < 0) {
 617                 pr_debug("Cache read error: %d\n", ret);
 618                 goto out_err;
 619         }
 620
 621         return pcache;
 622
 623 out_err:
 624         probe_cache__delete(pcache);
 625         return NULL;
 626 }
 627
 628 static bool streql(const char *a, const char *b)
 629 {
 630         if (a == b)
 631                 return true;
 632
 633         if (!a || !b)
 634                 return false;
 635
 636         return !strcmp(a, b);
 637 }
 638
 639 struct probe_cache_entry *
 640 probe_cache__find(struct probe_cache *pcache, struct perf_probe_event *pev)
 641 {
 642         struct probe_cache_entry *entry = NULL;
 643         char *cmd = synthesize_perf_probe_command(pev);
 644
 645         if (!cmd)
 646                 return NULL;
 647
 648         for_each_probe_cache_entry(entry, pcache) {
 649                 if (pev->sdt) {
 650                         if (entry->pev.event &&
 651                             streql(entry->pev.event, pev->event) &&
 652                             (!pev->group ||
 653                              streql(entry->pev.group, pev->group)))
 654                                 goto found;
 655
 656                         continue;
 657                 }
 658                 /* Hit if same event name or same command-string */
 659                 if ((pev->event &&
 660                      (streql(entry->pev.group, pev->group) &&
 661                       streql(entry->pev.event, pev->event))) ||
 662                     (!strcmp(entry->spev, cmd)))
 663                         goto found;
 664         }
 665         entry = NULL;
 666
 667 found:
 668         free(cmd);
 669         return entry;
 670 }
 671
 672 struct probe_cache_entry *
 673 probe_cache__find_by_name(struct probe_cache *pcache,
 674                           const char *group, const char *event)
 675 {
 676         struct probe_cache_entry *entry = NULL;
 677
 678         for_each_probe_cache_entry(entry, pcache) {
 679                 /* Hit if same event name or same command-string */
 680                 if (streql(entry->pev.group, group) &&
 681                     streql(entry->pev.event, event))
 682                         goto found;
 683         }
 684         entry = NULL;
 685
 686 found:
 687         return entry;
 688 }
 689
 690 int probe_cache__add_entry(struct probe_cache *pcache,
 691                            struct perf_probe_event *pev,
 692                            struct probe_trace_event *tevs, int ntevs)
 693 {
 694         struct probe_cache_entry *entry = NULL;
 695         char *command;
 696         int i, ret = 0;
 697
 698         if (!pcache || !pev || !tevs || ntevs <= 0) {
 699                 ret = -EINVAL;
 700                 goto out_err;
 701         }
 702
 703         /* Remove old cache entry */
 704         entry = probe_cache__find(pcache, pev);
 705         if (entry) {
 706                 list_del_init(&entry->node);
 707                 probe_cache_entry__delete(entry);
 708         }
 709
 710         ret = -ENOMEM;
 711         entry = probe_cache_entry__new(pev);
 712         if (!entry)
 713                 goto out_err;
 714
 715         for (i = 0; i < ntevs; i++) {
 716                 if (!tevs[i].point.symbol)
 717                         continue;
 718
 719                 command = synthesize_probe_trace_command(&tevs[i]);
 720                 if (!command)
 721                         goto out_err;
 722                 ret = strlist__add(entry->tevlist, command);
 723                 if (ret == -ENOMEM) {
 724                         pr_err("strlist__add failed with -ENOMEM\n");
 725                         goto out_err;
 726                 }
 727
 728                 free(command);
 729         }
 730         list_add_tail(&entry->node, &pcache->entries);
 731         pr_debug("Added probe cache: %d\n", ntevs);
 732         return 0;
 733
 734 out_err:
 735         pr_debug("Failed to add probe caches\n");
 736         probe_cache_entry__delete(entry);
 737         return ret;
 738 }
 739
 740 #ifdef HAVE_GELF_GETNOTE_SUPPORT
 741 static unsigned long long sdt_note__get_addr(struct sdt_note *note)
 742 {
 743         return note->bit32 ?
 744                 (unsigned long long)note->addr.a32[SDT_NOTE_IDX_LOC] :
 745                 (unsigned long long)note->addr.a64[SDT_NOTE_IDX_LOC];
 746 }
 747
 748 static unsigned long long sdt_note__get_ref_ctr_offset(struct sdt_note *note)
 749 {
 750         return note->bit32 ?
 751                 (unsigned long long)note->addr.a32[SDT_NOTE_IDX_REFCTR] :
 752                 (unsigned long long)note->addr.a64[SDT_NOTE_IDX_REFCTR];
 753 }
 754
 755 static const char * const type_to_suffix[] = {
 756         ":s64", "", "", "", ":s32", "", ":s16", ":s8",
 757         "", ":u8", ":u16", "", ":u32", "", "", "", ":u64"
 758 };
 759
 760 /*
 761  * Isolate the string number and convert it into a decimal value;
 762  * this will be an index to get suffix of the uprobe name (defining
 763  * the type)
 764  */
 765 static int sdt_arg_parse_size(char *n_ptr, const char **suffix)
 766 {
 767         long type_idx;
 768
 769         type_idx = strtol(n_ptr, NULL, 10);
 770         if (type_idx < -8 || type_idx > 8) {
 771                 pr_debug4("Failed to get a valid sdt type\n");
 772                 return -1;
 773         }
 774
 775         *suffix = type_to_suffix[type_idx + 8];
 776         return 0;
 777 }
 778
 779 static int synthesize_sdt_probe_arg(struct strbuf *buf, int i, const char *arg)
 780 {
 781         char *op, *desc = strdup(arg), *new_op = NULL;
 782         const char *suffix = "";
 783         int ret = -1;
 784
 785         if (desc == NULL) {
 786                 pr_debug4("Allocation error\n");
 787                 return ret;
 788         }
 789
 790         /*
 791          * Argument is in N@OP format. N is size of the argument and OP is
 792          * the actual assembly operand. N can be omitted; in that case
 793          * argument is just OP(without @).
 794          */
 795         op = strchr(desc, '@');
 796         if (op) {
 797                 op[0] = '\0';
 798                 op++;
 799
 800                 if (sdt_arg_parse_size(desc, &suffix))
 801                         goto error;
 802         } else {
 803                 op = desc;
 804         }
 805
 806         ret = arch_sdt_arg_parse_op(op, &new_op);
 807
 808         if (ret < 0)
 809                 goto error;
 810
 811         if (ret == SDT_ARG_VALID) {
 812                 ret = strbuf_addf(buf, " arg%d=%s%s", i + 1, new_op, suffix);
 813                 if (ret < 0)
 814                         goto error;
 815         }
 816
 817         ret = 0;
 818 error:
 819         free(desc);
 820         free(new_op);
 821         return ret;
 822 }
 823
 824 static char *synthesize_sdt_probe_command(struct sdt_note *note,
 825                                         const char *pathname,
 826                                         const char *sdtgrp)
 827 {
 828         struct strbuf buf;
 829         char *ret = NULL;
 830         int i, args_count, err;
 831         unsigned long long ref_ctr_offset;
 832         char *arg;
 833         int arg_idx = 0;
 834
 835         if (strbuf_init(&buf, 32) < 0)
 836                 return NULL;
 837
 838         err = strbuf_addf(&buf, "p:%s/%s %s:0x%llx",
 839                         sdtgrp, note->name, pathname,
 840                         sdt_note__get_addr(note));
 841
 842         ref_ctr_offset = sdt_note__get_ref_ctr_offset(note);
 843         if (ref_ctr_offset && err >= 0)
 844                 err = strbuf_addf(&buf, "(0x%llx)", ref_ctr_offset);
 845
 846         if (err < 0)
 847                 goto error;
 848
 849         if (!note->args)
 850                 goto out;
 851
 852         if (note->args) {
 853                 char **args = argv_split(note->args, &args_count);
 854
 855                 if (args == NULL)
 856                         goto error;
 857
 858                 for (i = 0; i < args_count; ) {
 859                         /*
 860                          * FIXUP: Arm64 ELF section '.note.stapsdt' uses string
 861                          * format "-4@[sp, NUM]" if a probe is to access data in
 862                          * the stack, e.g. below is an example for the SDT
 863                          * Arguments:
 864                          *
 865                          *   Arguments: -4@[sp, 12] -4@[sp, 8] -4@[sp, 4]
 866                          *
 867                          * Since the string introduces an extra space character
 868                          * in the middle of square brackets, the argument is
 869                          * divided into two items.  Fixup for this case, if an
 870                          * item contains sub string "[sp,", need to concatenate
 871                          * the two items.
 872                          */
 873                         if (strstr(args[i], "[sp,") && (i+1) < args_count) {
 874                                 err = asprintf(&arg, "%s %s", args[i], args[i+1]);
 875                                 i += 2;
 876                         } else {
 877                                 err = asprintf(&arg, "%s", args[i]);
 878                                 i += 1;
 879                         }
 880
 881                         /* Failed to allocate memory */
 882                         if (err < 0) {
 883                                 argv_free(args);
 884                                 goto error;
 885                         }
 886
 887                         if (synthesize_sdt_probe_arg(&buf, arg_idx, arg) < 0) {
 888                                 free(arg);
 889                                 argv_free(args);
 890                                 goto error;
 891                         }
 892
 893                         free(arg);
 894                         arg_idx++;
 895                 }
 896
 897                 argv_free(args);
 898         }
 899
 900 out:
 901         ret = strbuf_detach(&buf, NULL);
 902 error:
 903         strbuf_release(&buf);
 904         return ret;
 905 }
 906
 907 int probe_cache__scan_sdt(struct probe_cache *pcache, const char *pathname)
 908 {
 909         struct probe_cache_entry *entry = NULL;
 910         struct list_head sdtlist;
 911         struct sdt_note *note;
 912         char *buf;
 913         char sdtgrp[64];
 914         int ret;
 915
 916         INIT_LIST_HEAD(&sdtlist);
 917         ret = get_sdt_note_list(&sdtlist, pathname);
 918         if (ret < 0) {
 919                 pr_debug4("Failed to get sdt note: %d\n", ret);
 920                 return ret;
 921         }
 922         list_for_each_entry(note, &sdtlist, note_list) {
 923                 ret = snprintf(sdtgrp, 64, "sdt_%s", note->provider);
 924                 if (ret < 0)
 925                         break;
 926                 /* Try to find same-name entry */
 927                 entry = probe_cache__find_by_name(pcache, sdtgrp, note->name);
 928                 if (!entry) {
 929                         entry = probe_cache_entry__new(NULL);
 930                         if (!entry) {
 931                                 ret = -ENOMEM;
 932                                 break;
 933                         }
 934                         entry->sdt = true;
 935                         ret = asprintf(&entry->spev, "%s:%s=%s", sdtgrp,
 936                                         note->name, note->name);
 937                         if (ret < 0)
 938                                 break;
 939                         entry->pev.event = strdup(note->name);
 940                         entry->pev.group = strdup(sdtgrp);
 941                         list_add_tail(&entry->node, &pcache->entries);
 942                 }
 943                 buf = synthesize_sdt_probe_command(note, pathname, sdtgrp);
 944                 if (!buf) {
 945                         ret = -ENOMEM;
 946                         break;
 947                 }
 948
 949                 ret = strlist__add(entry->tevlist, buf);
 950
 951                 free(buf);
 952                 entry = NULL;
 953
 954                 if (ret == -ENOMEM) {
 955                         pr_err("strlist__add failed with -ENOMEM\n");
 956                         break;
 957                 }
 958         }
 959         if (entry) {
 960                 list_del_init(&entry->node);
 961                 probe_cache_entry__delete(entry);
 962         }
 963         cleanup_sdt_note_list(&sdtlist);
 964         return ret;
 965 }
 966 #endif
 967
 968 static int probe_cache_entry__write(struct probe_cache_entry *entry, int fd)
 969 {
 970         struct str_node *snode;
 971         struct stat st;
 972         struct iovec iov[3];
 973         const char *prefix = entry->sdt ? "%" : "#";
 974         int ret;
 975         /* Save stat for rollback */
 976         ret = fstat(fd, &st);
 977         if (ret < 0)
 978                 return ret;
 979
 980         pr_debug("Writing cache: %s%s\n", prefix, entry->spev);
 981         iov[0].iov_base = (void *)prefix; iov[0].iov_len = 1;
 982         iov[1].iov_base = entry->spev; iov[1].iov_len = strlen(entry->spev);
 983         iov[2].iov_base = (void *)"\n"; iov[2].iov_len = 1;
 984         ret = writev(fd, iov, 3);
 985         if (ret < (int)iov[1].iov_len + 2)
 986                 goto rollback;
 987
 988         strlist__for_each_entry(snode, entry->tevlist) {
 989                 iov[0].iov_base = (void *)snode->s;
 990                 iov[0].iov_len = strlen(snode->s);
 991                 iov[1].iov_base = (void *)"\n"; iov[1].iov_len = 1;
 992                 ret = writev(fd, iov, 2);
 993                 if (ret < (int)iov[0].iov_len + 1)
 994                         goto rollback;
 995         }
 996         return 0;
 997
 998 rollback:
 999         /* Rollback to avoid cache file corruption */
1000         if (ret > 0)
1001                 ret = -1;
1002         if (ftruncate(fd, st.st_size) < 0)
1003                 ret = -2;
1004
1005         return ret;
1006 }
1007
1008 int probe_cache__commit(struct probe_cache *pcache)
1009 {
1010         struct probe_cache_entry *entry;
1011         int ret = 0;
1012
1013         /* TBD: if we do not update existing entries, skip it */
1014         ret = lseek(pcache->fd, 0, SEEK_SET);
1015         if (ret < 0)
1016                 goto out;
1017
1018         ret = ftruncate(pcache->fd, 0);
1019         if (ret < 0)
1020                 goto out;
1021
1022         for_each_probe_cache_entry(entry, pcache) {
1023                 ret = probe_cache_entry__write(entry, pcache->fd);
1024                 pr_debug("Cache committed: %d\n", ret);
1025                 if (ret < 0)
1026                         break;
1027         }
1028 out:
1029         return ret;
1030 }
1031
1032 static bool probe_cache_entry__compare(struct probe_cache_entry *entry,
1033                                        struct strfilter *filter)
1034 {
1035         char buf[128], *ptr = entry->spev;
1036
1037         if (entry->pev.event) {
1038                 snprintf(buf, 128, "%s:%s", entry->pev.group, entry->pev.event);
1039                 ptr = buf;
1040         }
1041         return strfilter__compare(filter, ptr);
1042 }
1043
1044 int probe_cache__filter_purge(struct probe_cache *pcache,
1045                               struct strfilter *filter)
1046 {
1047         struct probe_cache_entry *entry, *tmp;
1048
1049         list_for_each_entry_safe(entry, tmp, &pcache->entries, node) {
1050                 if (probe_cache_entry__compare(entry, filter)) {
1051                         pr_info("Removed cached event: %s\n", entry->spev);
1052                         list_del_init(&entry->node);
1053                         probe_cache_entry__delete(entry);
1054                 }
1055         }
1056         return 0;
1057 }
1058
1059 static int probe_cache__show_entries(struct probe_cache *pcache,
1060                                      struct strfilter *filter)
1061 {
1062         struct probe_cache_entry *entry;
1063
1064         for_each_probe_cache_entry(entry, pcache) {
1065                 if (probe_cache_entry__compare(entry, filter))
1066                         printf("%s\n", entry->spev);
1067         }
1068         return 0;
1069 }
1070
1071 /* Show all cached probes */
1072 int probe_cache__show_all_caches(struct strfilter *filter)
1073 {
1074         struct probe_cache *pcache;
1075         struct strlist *bidlist;
1076         struct str_node *nd;
1077         char *buf = strfilter__string(filter);
1078
1079         pr_debug("list cache with filter: %s\n", buf);
1080         free(buf);
1081
1082         bidlist = build_id_cache__list_all(true);
1083         if (!bidlist) {
1084                 pr_debug("Failed to get buildids: %d\n", errno);
1085                 return -EINVAL;
1086         }
1087         strlist__for_each_entry(nd, bidlist) {
1088                 pcache = probe_cache__new(nd->s, NULL);
1089                 if (!pcache)
1090                         continue;
1091                 if (!list_empty(&pcache->entries)) {
1092                         buf = build_id_cache__origname(nd->s);
1093                         printf("%s (%s):\n", buf, nd->s);
1094                         free(buf);
1095                         probe_cache__show_entries(pcache, filter);
1096                 }
1097                 probe_cache__delete(pcache);
1098         }
1099         strlist__delete(bidlist);
1100
1101         return 0;
1102 }
1103
1104 enum ftrace_readme {
1105         FTRACE_README_PROBE_TYPE_X = 0,
1106         FTRACE_README_KRETPROBE_OFFSET,
1107         FTRACE_README_UPROBE_REF_CTR,
1108         FTRACE_README_USER_ACCESS,
1109         FTRACE_README_MULTIPROBE_EVENT,
1110         FTRACE_README_IMMEDIATE_VALUE,
1111         FTRACE_README_END,
1112 };
1113
1114 static struct {
1115         const char *pattern;
1116         bool avail;
1117 } ftrace_readme_table[] = {
1118 #define DEFINE_TYPE(idx, pat)                   \
1119         [idx] = {.pattern = pat, .avail = false}
1120         DEFINE_TYPE(FTRACE_README_PROBE_TYPE_X, "*type: * x8/16/32/64,*"),
1121         DEFINE_TYPE(FTRACE_README_KRETPROBE_OFFSET, "*place (kretprobe): *"),
1122         DEFINE_TYPE(FTRACE_README_UPROBE_REF_CTR, "*ref_ctr_offset*"),
1123         DEFINE_TYPE(FTRACE_README_USER_ACCESS, "*u]<offset>*"),
1124         DEFINE_TYPE(FTRACE_README_MULTIPROBE_EVENT, "*Create/append/*"),
1125         DEFINE_TYPE(FTRACE_README_IMMEDIATE_VALUE, "*\\imm-value,*"),
1126 };
1127
1128 static bool scan_ftrace_readme(enum ftrace_readme type)
1129 {
1130         int fd;
1131         FILE *fp;
1132         char *buf = NULL;
1133         size_t len = 0;
1134         bool ret = false;
1135         static bool scanned = false;
1136
1137         if (scanned)
1138                 goto result;
1139
1140         fd = open_trace_file("README", false);
1141         if (fd < 0)
1142                 return ret;
1143
1144         fp = fdopen(fd, "r");
1145         if (!fp) {
1146                 close(fd);
1147                 return ret;
1148         }
1149
1150         while (getline(&buf, &len, fp) > 0)
1151                 for (enum ftrace_readme i = 0; i < FTRACE_README_END; i++)
1152                         if (!ftrace_readme_table[i].avail)
1153                                 ftrace_readme_table[i].avail =
1154                                         strglobmatch(buf, ftrace_readme_table[i].pattern);
1155         scanned = true;
1156
1157         fclose(fp);
1158         free(buf);
1159
1160 result:
1161         if (type >= FTRACE_README_END)
1162                 return false;
1163
1164         return ftrace_readme_table[type].avail;
1165 }
1166
1167 bool probe_type_is_available(enum probe_type type)
1168 {
1169         if (type >= PROBE_TYPE_END)
1170                 return false;
1171         else if (type == PROBE_TYPE_X)
1172                 return scan_ftrace_readme(FTRACE_README_PROBE_TYPE_X);
1173
1174         return true;
1175 }
1176
1177 bool kretprobe_offset_is_supported(void)
1178 {
1179         return scan_ftrace_readme(FTRACE_README_KRETPROBE_OFFSET);
1180 }
1181
1182 bool uprobe_ref_ctr_is_supported(void)
1183 {
1184         return scan_ftrace_readme(FTRACE_README_UPROBE_REF_CTR);
1185 }
1186
1187 bool user_access_is_supported(void)
1188 {
1189         return scan_ftrace_readme(FTRACE_README_USER_ACCESS);
1190 }
1191
1192 bool multiprobe_event_is_supported(void)
1193 {
1194         return scan_ftrace_readme(FTRACE_README_MULTIPROBE_EVENT);
1195 }
1196
1197 bool immediate_value_is_supported(void)
1198 {
1199         return scan_ftrace_readme(FTRACE_README_IMMEDIATE_VALUE);
1200 }