linux/tools/perf/util/probe-file.c
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   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 * probe-file.c : operate ftrace k/uprobe events files
   4 *
   5 * Written by Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
   6 */
   7#include <errno.h>
   8#include <fcntl.h>
   9#include <sys/stat.h>
  10#include <sys/types.h>
  11#include <sys/uio.h>
  12#include <unistd.h>
  13#include <linux/zalloc.h>
  14#include "namespaces.h"
  15#include "event.h"
  16#include "strlist.h"
  17#include "strfilter.h"
  18#include "debug.h"
  19#include "build-id.h"
  20#include "dso.h"
  21#include "color.h"
  22#include "symbol.h"
  23#include "strbuf.h"
  24#include <api/fs/tracing_path.h>
  25#include "probe-event.h"
  26#include "probe-file.h"
  27#include "session.h"
  28#include "perf_regs.h"
  29#include "string2.h"
  30
  31/* 4096 - 2 ('\n' + '\0') */
  32#define MAX_CMDLEN 4094
  33
  34static void print_open_warning(int err, bool uprobe)
  35{
  36        char sbuf[STRERR_BUFSIZE];
  37
  38        if (err == -ENOENT) {
  39                const char *config;
  40
  41                if (uprobe)
  42                        config = "CONFIG_UPROBE_EVENTS";
  43                else
  44                        config = "CONFIG_KPROBE_EVENTS";
  45
  46                pr_warning("%cprobe_events file does not exist"
  47                           " - please rebuild kernel with %s.\n",
  48                           uprobe ? 'u' : 'k', config);
  49        } else if (err == -ENOTSUP)
  50                pr_warning("Tracefs or debugfs is not mounted.\n");
  51        else
  52                pr_warning("Failed to open %cprobe_events: %s\n",
  53                           uprobe ? 'u' : 'k',
  54                           str_error_r(-err, sbuf, sizeof(sbuf)));
  55}
  56
  57static void print_both_open_warning(int kerr, int uerr)
  58{
  59        /* Both kprobes and uprobes are disabled, warn it. */
  60        if (kerr == -ENOTSUP && uerr == -ENOTSUP)
  61                pr_warning("Tracefs or debugfs is not mounted.\n");
  62        else if (kerr == -ENOENT && uerr == -ENOENT)
  63                pr_warning("Please rebuild kernel with CONFIG_KPROBE_EVENTS "
  64                           "or/and CONFIG_UPROBE_EVENTS.\n");
  65        else {
  66                char sbuf[STRERR_BUFSIZE];
  67                pr_warning("Failed to open kprobe events: %s.\n",
  68                           str_error_r(-kerr, sbuf, sizeof(sbuf)));
  69                pr_warning("Failed to open uprobe events: %s.\n",
  70                           str_error_r(-uerr, sbuf, sizeof(sbuf)));
  71        }
  72}
  73
  74int open_trace_file(const char *trace_file, bool readwrite)
  75{
  76        char buf[PATH_MAX];
  77        int ret;
  78
  79        ret = e_snprintf(buf, PATH_MAX, "%s/%s", tracing_path_mount(), trace_file);
  80        if (ret >= 0) {
  81                pr_debug("Opening %s write=%d\n", buf, readwrite);
  82                if (readwrite && !probe_event_dry_run)
  83                        ret = open(buf, O_RDWR | O_APPEND, 0);
  84                else
  85                        ret = open(buf, O_RDONLY, 0);
  86
  87                if (ret < 0)
  88                        ret = -errno;
  89        }
  90        return ret;
  91}
  92
  93static int open_kprobe_events(bool readwrite)
  94{
  95        return open_trace_file("kprobe_events", readwrite);
  96}
  97
  98static int open_uprobe_events(bool readwrite)
  99{
 100        return open_trace_file("uprobe_events", readwrite);
 101}
 102
 103int probe_file__open(int flag)
 104{
 105        int fd;
 106
 107        if (flag & PF_FL_UPROBE)
 108                fd = open_uprobe_events(flag & PF_FL_RW);
 109        else
 110                fd = open_kprobe_events(flag & PF_FL_RW);
 111        if (fd < 0)
 112                print_open_warning(fd, flag & PF_FL_UPROBE);
 113
 114        return fd;
 115}
 116
 117int probe_file__open_both(int *kfd, int *ufd, int flag)
 118{
 119        if (!kfd || !ufd)
 120                return -EINVAL;
 121
 122        *kfd = open_kprobe_events(flag & PF_FL_RW);
 123        *ufd = open_uprobe_events(flag & PF_FL_RW);
 124        if (*kfd < 0 && *ufd < 0) {
 125                print_both_open_warning(*kfd, *ufd);
 126                return *kfd;
 127        }
 128
 129        return 0;
 130}
 131
 132/* Get raw string list of current kprobe_events  or uprobe_events */
 133struct strlist *probe_file__get_rawlist(int fd)
 134{
 135        int ret, idx, fddup;
 136        FILE *fp;
 137        char buf[MAX_CMDLEN];
 138        char *p;
 139        struct strlist *sl;
 140
 141        if (fd < 0)
 142                return NULL;
 143
 144        sl = strlist__new(NULL, NULL);
 145        if (sl == NULL)
 146                return NULL;
 147
 148        fddup = dup(fd);
 149        if (fddup < 0)
 150                goto out_free_sl;
 151
 152        fp = fdopen(fddup, "r");
 153        if (!fp)
 154                goto out_close_fddup;
 155
 156        while (!feof(fp)) {
 157                p = fgets(buf, MAX_CMDLEN, fp);
 158                if (!p)
 159                        break;
 160
 161                idx = strlen(p) - 1;
 162                if (p[idx] == '\n')
 163                        p[idx] = '\0';
 164                ret = strlist__add(sl, buf);
 165                if (ret < 0) {
 166                        pr_debug("strlist__add failed (%d)\n", ret);
 167                        goto out_close_fp;
 168                }
 169        }
 170        fclose(fp);
 171
 172        return sl;
 173
 174out_close_fp:
 175        fclose(fp);
 176        goto out_free_sl;
 177out_close_fddup:
 178        close(fddup);
 179out_free_sl:
 180        strlist__delete(sl);
 181        return NULL;
 182}
 183
 184static struct strlist *__probe_file__get_namelist(int fd, bool include_group)
 185{
 186        char buf[128];
 187        struct strlist *sl, *rawlist;
 188        struct str_node *ent;
 189        struct probe_trace_event tev;
 190        int ret = 0;
 191
 192        memset(&tev, 0, sizeof(tev));
 193        rawlist = probe_file__get_rawlist(fd);
 194        if (!rawlist)
 195                return NULL;
 196        sl = strlist__new(NULL, NULL);
 197        strlist__for_each_entry(ent, rawlist) {
 198                ret = parse_probe_trace_command(ent->s, &tev);
 199                if (ret < 0)
 200                        break;
 201                if (include_group) {
 202                        ret = e_snprintf(buf, 128, "%s:%s", tev.group,
 203                                        tev.event);
 204                        if (ret >= 0)
 205                                ret = strlist__add(sl, buf);
 206                } else
 207                        ret = strlist__add(sl, tev.event);
 208                clear_probe_trace_event(&tev);
 209                /* Skip if there is same name multi-probe event in the list */
 210                if (ret == -EEXIST)
 211                        ret = 0;
 212                if (ret < 0)
 213                        break;
 214        }
 215        strlist__delete(rawlist);
 216
 217        if (ret < 0) {
 218                strlist__delete(sl);
 219                return NULL;
 220        }
 221        return sl;
 222}
 223
 224/* Get current perf-probe event names */
 225struct strlist *probe_file__get_namelist(int fd)
 226{
 227        return __probe_file__get_namelist(fd, false);
 228}
 229
 230int probe_file__add_event(int fd, struct probe_trace_event *tev)
 231{
 232        int ret = 0;
 233        char *buf = synthesize_probe_trace_command(tev);
 234        char sbuf[STRERR_BUFSIZE];
 235
 236        if (!buf) {
 237                pr_debug("Failed to synthesize probe trace event.\n");
 238                return -EINVAL;
 239        }
 240
 241        pr_debug("Writing event: %s\n", buf);
 242        if (!probe_event_dry_run) {
 243                if (write(fd, buf, strlen(buf)) < (int)strlen(buf)) {
 244                        ret = -errno;
 245                        pr_warning("Failed to write event: %s\n",
 246                                   str_error_r(errno, sbuf, sizeof(sbuf)));
 247                }
 248        }
 249        free(buf);
 250
 251        return ret;
 252}
 253
 254static int __del_trace_probe_event(int fd, struct str_node *ent)
 255{
 256        char *p;
 257        char buf[128];
 258        int ret;
 259
 260        /* Convert from perf-probe event to trace-probe event */
 261        ret = e_snprintf(buf, 128, "-:%s", ent->s);
 262        if (ret < 0)
 263                goto error;
 264
 265        p = strchr(buf + 2, ':');
 266        if (!p) {
 267                pr_debug("Internal error: %s should have ':' but not.\n",
 268                         ent->s);
 269                ret = -ENOTSUP;
 270                goto error;
 271        }
 272        *p = '/';
 273
 274        pr_debug("Writing event: %s\n", buf);
 275        ret = write(fd, buf, strlen(buf));
 276        if (ret < 0) {
 277                ret = -errno;
 278                goto error;
 279        }
 280
 281        return 0;
 282error:
 283        pr_warning("Failed to delete event: %s\n",
 284                   str_error_r(-ret, buf, sizeof(buf)));
 285        return ret;
 286}
 287
 288int probe_file__get_events(int fd, struct strfilter *filter,
 289                           struct strlist *plist)
 290{
 291        struct strlist *namelist;
 292        struct str_node *ent;
 293        const char *p;
 294        int ret = -ENOENT;
 295
 296        if (!plist)
 297                return -EINVAL;
 298
 299        namelist = __probe_file__get_namelist(fd, true);
 300        if (!namelist)
 301                return -ENOENT;
 302
 303        strlist__for_each_entry(ent, namelist) {
 304                p = strchr(ent->s, ':');
 305                if ((p && strfilter__compare(filter, p + 1)) ||
 306                    strfilter__compare(filter, ent->s)) {
 307                        ret = strlist__add(plist, ent->s);
 308                        if (ret == -ENOMEM) {
 309                                pr_err("strlist__add failed with -ENOMEM\n");
 310                                goto out;
 311                        }
 312                        ret = 0;
 313                }
 314        }
 315out:
 316        strlist__delete(namelist);
 317
 318        return ret;
 319}
 320
 321int 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
 334int 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 */
 354static 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
 366static struct probe_cache_entry *
 367probe_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
 389int 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 */
 415static int probe_cache__open(struct probe_cache *pcache, const char *target,
 416                             struct nsinfo *nsi)
 417{
 418        char cpath[PATH_MAX];
 419        char sbuildid[SBUILD_ID_SIZE];
 420        char *dir_name = NULL;
 421        bool is_kallsyms = false;
 422        int ret, fd;
 423        struct nscookie nsc;
 424
 425        if (target && build_id_cache__cached(target)) {
 426                /* This is a cached buildid */
 427                strlcpy(sbuildid, target, SBUILD_ID_SIZE);
 428                dir_name = build_id_cache__linkname(sbuildid, NULL, 0);
 429                goto found;
 430        }
 431
 432        if (!target || !strcmp(target, DSO__NAME_KALLSYMS)) {
 433                target = DSO__NAME_KALLSYMS;
 434                is_kallsyms = true;
 435                ret = sysfs__sprintf_build_id("/", sbuildid);
 436        } else {
 437                nsinfo__mountns_enter(nsi, &nsc);
 438                ret = filename__sprintf_build_id(target, sbuildid);
 439                nsinfo__mountns_exit(&nsc);
 440        }
 441
 442        if (ret < 0) {
 443                pr_debug("Failed to get build-id from %s.\n", target);
 444                return ret;
 445        }
 446
 447        /* If we have no buildid cache, make it */
 448        if (!build_id_cache__cached(sbuildid)) {
 449                ret = build_id_cache__add_s(sbuildid, target, nsi,
 450                                            is_kallsyms, NULL);
 451                if (ret < 0) {
 452                        pr_debug("Failed to add build-id cache: %s\n", target);
 453                        return ret;
 454                }
 455        }
 456
 457        dir_name = build_id_cache__cachedir(sbuildid, target, nsi, is_kallsyms,
 458                                            false);
 459found:
 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
 475static int probe_cache__load(struct probe_cache *pcache)
 476{
 477        struct probe_cache_entry *entry = NULL;
 478        char buf[MAX_CMDLEN], *p;
 479        int ret = 0, fddup;
 480        FILE *fp;
 481
 482        fddup = dup(pcache->fd);
 483        if (fddup < 0)
 484                return -errno;
 485        fp = fdopen(fddup, "r");
 486        if (!fp) {
 487                close(fddup);
 488                return -EINVAL;
 489        }
 490
 491        while (!feof(fp)) {
 492                if (!fgets(buf, MAX_CMDLEN, fp))
 493                        break;
 494                p = strchr(buf, '\n');
 495                if (p)
 496                        *p = '\0';
 497                /* #perf_probe_event or %sdt_event */
 498                if (buf[0] == '#' || buf[0] == '%') {
 499                        entry = probe_cache_entry__new(NULL);
 500                        if (!entry) {
 501                                ret = -ENOMEM;
 502                                goto out;
 503                        }
 504                        if (buf[0] == '%')
 505                                entry->sdt = true;
 506                        entry->spev = strdup(buf + 1);
 507                        if (entry->spev)
 508                                ret = parse_perf_probe_command(buf + 1,
 509                                                                &entry->pev);
 510                        else
 511                                ret = -ENOMEM;
 512                        if (ret < 0) {
 513                                probe_cache_entry__delete(entry);
 514                                goto out;
 515                        }
 516                        list_add_tail(&entry->node, &pcache->entries);
 517                } else {        /* trace_probe_event */
 518                        if (!entry) {
 519                                ret = -EINVAL;
 520                                goto out;
 521                        }
 522                        ret = strlist__add(entry->tevlist, buf);
 523                        if (ret == -ENOMEM) {
 524                                pr_err("strlist__add failed with -ENOMEM\n");
 525                                goto out;
 526                        }
 527                }
 528        }
 529out:
 530        fclose(fp);
 531        return ret;
 532}
 533
 534static struct probe_cache *probe_cache__alloc(void)
 535{
 536        struct probe_cache *pcache = zalloc(sizeof(*pcache));
 537
 538        if (pcache) {
 539                INIT_LIST_HEAD(&pcache->entries);
 540                pcache->fd = -EINVAL;
 541        }
 542        return pcache;
 543}
 544
 545void probe_cache__purge(struct probe_cache *pcache)
 546{
 547        struct probe_cache_entry *entry, *n;
 548
 549        list_for_each_entry_safe(entry, n, &pcache->entries, node) {
 550                list_del_init(&entry->node);
 551                probe_cache_entry__delete(entry);
 552        }
 553}
 554
 555void probe_cache__delete(struct probe_cache *pcache)
 556{
 557        if (!pcache)
 558                return;
 559
 560        probe_cache__purge(pcache);
 561        if (pcache->fd > 0)
 562                close(pcache->fd);
 563        free(pcache);
 564}
 565
 566struct probe_cache *probe_cache__new(const char *target, struct nsinfo *nsi)
 567{
 568        struct probe_cache *pcache = probe_cache__alloc();
 569        int ret;
 570
 571        if (!pcache)
 572                return NULL;
 573
 574        ret = probe_cache__open(pcache, target, nsi);
 575        if (ret < 0) {
 576                pr_debug("Cache open error: %d\n", ret);
 577                goto out_err;
 578        }
 579
 580        ret = probe_cache__load(pcache);
 581        if (ret < 0) {
 582                pr_debug("Cache read error: %d\n", ret);
 583                goto out_err;
 584        }
 585
 586        return pcache;
 587
 588out_err:
 589        probe_cache__delete(pcache);
 590        return NULL;
 591}
 592
 593static bool streql(const char *a, const char *b)
 594{
 595        if (a == b)
 596                return true;
 597
 598        if (!a || !b)
 599                return false;
 600
 601        return !strcmp(a, b);
 602}
 603
 604struct probe_cache_entry *
 605probe_cache__find(struct probe_cache *pcache, struct perf_probe_event *pev)
 606{
 607        struct probe_cache_entry *entry = NULL;
 608        char *cmd = synthesize_perf_probe_command(pev);
 609
 610        if (!cmd)
 611                return NULL;
 612
 613        for_each_probe_cache_entry(entry, pcache) {
 614                if (pev->sdt) {
 615                        if (entry->pev.event &&
 616                            streql(entry->pev.event, pev->event) &&
 617                            (!pev->group ||
 618                             streql(entry->pev.group, pev->group)))
 619                                goto found;
 620
 621                        continue;
 622                }
 623                /* Hit if same event name or same command-string */
 624                if ((pev->event &&
 625                     (streql(entry->pev.group, pev->group) &&
 626                      streql(entry->pev.event, pev->event))) ||
 627                    (!strcmp(entry->spev, cmd)))
 628                        goto found;
 629        }
 630        entry = NULL;
 631
 632found:
 633        free(cmd);
 634        return entry;
 635}
 636
 637struct probe_cache_entry *
 638probe_cache__find_by_name(struct probe_cache *pcache,
 639                          const char *group, const char *event)
 640{
 641        struct probe_cache_entry *entry = NULL;
 642
 643        for_each_probe_cache_entry(entry, pcache) {
 644                /* Hit if same event name or same command-string */
 645                if (streql(entry->pev.group, group) &&
 646                    streql(entry->pev.event, event))
 647                        goto found;
 648        }
 649        entry = NULL;
 650
 651found:
 652        return entry;
 653}
 654
 655int probe_cache__add_entry(struct probe_cache *pcache,
 656                           struct perf_probe_event *pev,
 657                           struct probe_trace_event *tevs, int ntevs)
 658{
 659        struct probe_cache_entry *entry = NULL;
 660        char *command;
 661        int i, ret = 0;
 662
 663        if (!pcache || !pev || !tevs || ntevs <= 0) {
 664                ret = -EINVAL;
 665                goto out_err;
 666        }
 667
 668        /* Remove old cache entry */
 669        entry = probe_cache__find(pcache, pev);
 670        if (entry) {
 671                list_del_init(&entry->node);
 672                probe_cache_entry__delete(entry);
 673        }
 674
 675        ret = -ENOMEM;
 676        entry = probe_cache_entry__new(pev);
 677        if (!entry)
 678                goto out_err;
 679
 680        for (i = 0; i < ntevs; i++) {
 681                if (!tevs[i].point.symbol)
 682                        continue;
 683
 684                command = synthesize_probe_trace_command(&tevs[i]);
 685                if (!command)
 686                        goto out_err;
 687                ret = strlist__add(entry->tevlist, command);
 688                if (ret == -ENOMEM) {
 689                        pr_err("strlist__add failed with -ENOMEM\n");
 690                        goto out_err;
 691                }
 692
 693                free(command);
 694        }
 695        list_add_tail(&entry->node, &pcache->entries);
 696        pr_debug("Added probe cache: %d\n", ntevs);
 697        return 0;
 698
 699out_err:
 700        pr_debug("Failed to add probe caches\n");
 701        probe_cache_entry__delete(entry);
 702        return ret;
 703}
 704
 705#ifdef HAVE_GELF_GETNOTE_SUPPORT
 706static unsigned long long sdt_note__get_addr(struct sdt_note *note)
 707{
 708        return note->bit32 ?
 709                (unsigned long long)note->addr.a32[SDT_NOTE_IDX_LOC] :
 710                (unsigned long long)note->addr.a64[SDT_NOTE_IDX_LOC];
 711}
 712
 713static unsigned long long sdt_note__get_ref_ctr_offset(struct sdt_note *note)
 714{
 715        return note->bit32 ?
 716                (unsigned long long)note->addr.a32[SDT_NOTE_IDX_REFCTR] :
 717                (unsigned long long)note->addr.a64[SDT_NOTE_IDX_REFCTR];
 718}
 719
 720static const char * const type_to_suffix[] = {
 721        ":s64", "", "", "", ":s32", "", ":s16", ":s8",
 722        "", ":u8", ":u16", "", ":u32", "", "", "", ":u64"
 723};
 724
 725/*
 726 * Isolate the string number and convert it into a decimal value;
 727 * this will be an index to get suffix of the uprobe name (defining
 728 * the type)
 729 */
 730static int sdt_arg_parse_size(char *n_ptr, const char **suffix)
 731{
 732        long type_idx;
 733
 734        type_idx = strtol(n_ptr, NULL, 10);
 735        if (type_idx < -8 || type_idx > 8) {
 736                pr_debug4("Failed to get a valid sdt type\n");
 737                return -1;
 738        }
 739
 740        *suffix = type_to_suffix[type_idx + 8];
 741        return 0;
 742}
 743
 744static int synthesize_sdt_probe_arg(struct strbuf *buf, int i, const char *arg)
 745{
 746        char *op, *desc = strdup(arg), *new_op = NULL;
 747        const char *suffix = "";
 748        int ret = -1;
 749
 750        if (desc == NULL) {
 751                pr_debug4("Allocation error\n");
 752                return ret;
 753        }
 754
 755        /*
 756         * Argument is in N@OP format. N is size of the argument and OP is
 757         * the actual assembly operand. N can be omitted; in that case
 758         * argument is just OP(without @).
 759         */
 760        op = strchr(desc, '@');
 761        if (op) {
 762                op[0] = '\0';
 763                op++;
 764
 765                if (sdt_arg_parse_size(desc, &suffix))
 766                        goto error;
 767        } else {
 768                op = desc;
 769        }
 770
 771        ret = arch_sdt_arg_parse_op(op, &new_op);
 772
 773        if (ret < 0)
 774                goto error;
 775
 776        if (ret == SDT_ARG_VALID) {
 777                ret = strbuf_addf(buf, " arg%d=%s%s", i + 1, new_op, suffix);
 778                if (ret < 0)
 779                        goto error;
 780        }
 781
 782        ret = 0;
 783error:
 784        free(desc);
 785        free(new_op);
 786        return ret;
 787}
 788
 789static char *synthesize_sdt_probe_command(struct sdt_note *note,
 790                                        const char *pathname,
 791                                        const char *sdtgrp)
 792{
 793        struct strbuf buf;
 794        char *ret = NULL, **args;
 795        int i, args_count, err;
 796        unsigned long long ref_ctr_offset;
 797
 798        if (strbuf_init(&buf, 32) < 0)
 799                return NULL;
 800
 801        err = strbuf_addf(&buf, "p:%s/%s %s:0x%llx",
 802                        sdtgrp, note->name, pathname,
 803                        sdt_note__get_addr(note));
 804
 805        ref_ctr_offset = sdt_note__get_ref_ctr_offset(note);
 806        if (ref_ctr_offset && err >= 0)
 807                err = strbuf_addf(&buf, "(0x%llx)", ref_ctr_offset);
 808
 809        if (err < 0)
 810                goto error;
 811
 812        if (!note->args)
 813                goto out;
 814
 815        if (note->args) {
 816                args = argv_split(note->args, &args_count);
 817
 818                for (i = 0; i < args_count; ++i) {
 819                        if (synthesize_sdt_probe_arg(&buf, i, args[i]) < 0)
 820                                goto error;
 821                }
 822        }
 823
 824out:
 825        ret = strbuf_detach(&buf, NULL);
 826error:
 827        strbuf_release(&buf);
 828        return ret;
 829}
 830
 831int probe_cache__scan_sdt(struct probe_cache *pcache, const char *pathname)
 832{
 833        struct probe_cache_entry *entry = NULL;
 834        struct list_head sdtlist;
 835        struct sdt_note *note;
 836        char *buf;
 837        char sdtgrp[64];
 838        int ret;
 839
 840        INIT_LIST_HEAD(&sdtlist);
 841        ret = get_sdt_note_list(&sdtlist, pathname);
 842        if (ret < 0) {
 843                pr_debug4("Failed to get sdt note: %d\n", ret);
 844                return ret;
 845        }
 846        list_for_each_entry(note, &sdtlist, note_list) {
 847                ret = snprintf(sdtgrp, 64, "sdt_%s", note->provider);
 848                if (ret < 0)
 849                        break;
 850                /* Try to find same-name entry */
 851                entry = probe_cache__find_by_name(pcache, sdtgrp, note->name);
 852                if (!entry) {
 853                        entry = probe_cache_entry__new(NULL);
 854                        if (!entry) {
 855                                ret = -ENOMEM;
 856                                break;
 857                        }
 858                        entry->sdt = true;
 859                        ret = asprintf(&entry->spev, "%s:%s=%s", sdtgrp,
 860                                        note->name, note->name);
 861                        if (ret < 0)
 862                                break;
 863                        entry->pev.event = strdup(note->name);
 864                        entry->pev.group = strdup(sdtgrp);
 865                        list_add_tail(&entry->node, &pcache->entries);
 866                }
 867                buf = synthesize_sdt_probe_command(note, pathname, sdtgrp);
 868                if (!buf) {
 869                        ret = -ENOMEM;
 870                        break;
 871                }
 872
 873                ret = strlist__add(entry->tevlist, buf);
 874
 875                free(buf);
 876                entry = NULL;
 877
 878                if (ret == -ENOMEM) {
 879                        pr_err("strlist__add failed with -ENOMEM\n");
 880                        break;
 881                }
 882        }
 883        if (entry) {
 884                list_del_init(&entry->node);
 885                probe_cache_entry__delete(entry);
 886        }
 887        cleanup_sdt_note_list(&sdtlist);
 888        return ret;
 889}
 890#endif
 891
 892static int probe_cache_entry__write(struct probe_cache_entry *entry, int fd)
 893{
 894        struct str_node *snode;
 895        struct stat st;
 896        struct iovec iov[3];
 897        const char *prefix = entry->sdt ? "%" : "#";
 898        int ret;
 899        /* Save stat for rollback */
 900        ret = fstat(fd, &st);
 901        if (ret < 0)
 902                return ret;
 903
 904        pr_debug("Writing cache: %s%s\n", prefix, entry->spev);
 905        iov[0].iov_base = (void *)prefix; iov[0].iov_len = 1;
 906        iov[1].iov_base = entry->spev; iov[1].iov_len = strlen(entry->spev);
 907        iov[2].iov_base = (void *)"\n"; iov[2].iov_len = 1;
 908        ret = writev(fd, iov, 3);
 909        if (ret < (int)iov[1].iov_len + 2)
 910                goto rollback;
 911
 912        strlist__for_each_entry(snode, entry->tevlist) {
 913                iov[0].iov_base = (void *)snode->s;
 914                iov[0].iov_len = strlen(snode->s);
 915                iov[1].iov_base = (void *)"\n"; iov[1].iov_len = 1;
 916                ret = writev(fd, iov, 2);
 917                if (ret < (int)iov[0].iov_len + 1)
 918                        goto rollback;
 919        }
 920        return 0;
 921
 922rollback:
 923        /* Rollback to avoid cache file corruption */
 924        if (ret > 0)
 925                ret = -1;
 926        if (ftruncate(fd, st.st_size) < 0)
 927                ret = -2;
 928
 929        return ret;
 930}
 931
 932int probe_cache__commit(struct probe_cache *pcache)
 933{
 934        struct probe_cache_entry *entry;
 935        int ret = 0;
 936
 937        /* TBD: if we do not update existing entries, skip it */
 938        ret = lseek(pcache->fd, 0, SEEK_SET);
 939        if (ret < 0)
 940                goto out;
 941
 942        ret = ftruncate(pcache->fd, 0);
 943        if (ret < 0)
 944                goto out;
 945
 946        for_each_probe_cache_entry(entry, pcache) {
 947                ret = probe_cache_entry__write(entry, pcache->fd);
 948                pr_debug("Cache committed: %d\n", ret);
 949                if (ret < 0)
 950                        break;
 951        }
 952out:
 953        return ret;
 954}
 955
 956static bool probe_cache_entry__compare(struct probe_cache_entry *entry,
 957                                       struct strfilter *filter)
 958{
 959        char buf[128], *ptr = entry->spev;
 960
 961        if (entry->pev.event) {
 962                snprintf(buf, 128, "%s:%s", entry->pev.group, entry->pev.event);
 963                ptr = buf;
 964        }
 965        return strfilter__compare(filter, ptr);
 966}
 967
 968int probe_cache__filter_purge(struct probe_cache *pcache,
 969                              struct strfilter *filter)
 970{
 971        struct probe_cache_entry *entry, *tmp;
 972
 973        list_for_each_entry_safe(entry, tmp, &pcache->entries, node) {
 974                if (probe_cache_entry__compare(entry, filter)) {
 975                        pr_info("Removed cached event: %s\n", entry->spev);
 976                        list_del_init(&entry->node);
 977                        probe_cache_entry__delete(entry);
 978                }
 979        }
 980        return 0;
 981}
 982
 983static int probe_cache__show_entries(struct probe_cache *pcache,
 984                                     struct strfilter *filter)
 985{
 986        struct probe_cache_entry *entry;
 987
 988        for_each_probe_cache_entry(entry, pcache) {
 989                if (probe_cache_entry__compare(entry, filter))
 990                        printf("%s\n", entry->spev);
 991        }
 992        return 0;
 993}
 994
 995/* Show all cached probes */
 996int probe_cache__show_all_caches(struct strfilter *filter)
 997{
 998        struct probe_cache *pcache;
 999        struct strlist *bidlist;
1000        struct str_node *nd;
1001        char *buf = strfilter__string(filter);
1002
1003        pr_debug("list cache with filter: %s\n", buf);
1004        free(buf);
1005
1006        bidlist = build_id_cache__list_all(true);
1007        if (!bidlist) {
1008                pr_debug("Failed to get buildids: %d\n", errno);
1009                return -EINVAL;
1010        }
1011        strlist__for_each_entry(nd, bidlist) {
1012                pcache = probe_cache__new(nd->s, NULL);
1013                if (!pcache)
1014                        continue;
1015                if (!list_empty(&pcache->entries)) {
1016                        buf = build_id_cache__origname(nd->s);
1017                        printf("%s (%s):\n", buf, nd->s);
1018                        free(buf);
1019                        probe_cache__show_entries(pcache, filter);
1020                }
1021                probe_cache__delete(pcache);
1022        }
1023        strlist__delete(bidlist);
1024
1025        return 0;
1026}
1027
1028enum ftrace_readme {
1029        FTRACE_README_PROBE_TYPE_X = 0,
1030        FTRACE_README_KRETPROBE_OFFSET,
1031        FTRACE_README_UPROBE_REF_CTR,
1032        FTRACE_README_USER_ACCESS,
1033        FTRACE_README_MULTIPROBE_EVENT,
1034        FTRACE_README_IMMEDIATE_VALUE,
1035        FTRACE_README_END,
1036};
1037
1038static struct {
1039        const char *pattern;
1040        bool avail;
1041} ftrace_readme_table[] = {
1042#define DEFINE_TYPE(idx, pat)                   \
1043        [idx] = {.pattern = pat, .avail = false}
1044        DEFINE_TYPE(FTRACE_README_PROBE_TYPE_X, "*type: * x8/16/32/64,*"),
1045        DEFINE_TYPE(FTRACE_README_KRETPROBE_OFFSET, "*place (kretprobe): *"),
1046        DEFINE_TYPE(FTRACE_README_UPROBE_REF_CTR, "*ref_ctr_offset*"),
1047        DEFINE_TYPE(FTRACE_README_USER_ACCESS, "*u]<offset>*"),
1048        DEFINE_TYPE(FTRACE_README_MULTIPROBE_EVENT, "*Create/append/*"),
1049        DEFINE_TYPE(FTRACE_README_IMMEDIATE_VALUE, "*\\imm-value,*"),
1050};
1051
1052static bool scan_ftrace_readme(enum ftrace_readme type)
1053{
1054        int fd;
1055        FILE *fp;
1056        char *buf = NULL;
1057        size_t len = 0;
1058        bool ret = false;
1059        static bool scanned = false;
1060
1061        if (scanned)
1062                goto result;
1063
1064        fd = open_trace_file("README", false);
1065        if (fd < 0)
1066                return ret;
1067
1068        fp = fdopen(fd, "r");
1069        if (!fp) {
1070                close(fd);
1071                return ret;
1072        }
1073
1074        while (getline(&buf, &len, fp) > 0)
1075                for (enum ftrace_readme i = 0; i < FTRACE_README_END; i++)
1076                        if (!ftrace_readme_table[i].avail)
1077                                ftrace_readme_table[i].avail =
1078                                        strglobmatch(buf, ftrace_readme_table[i].pattern);
1079        scanned = true;
1080
1081        fclose(fp);
1082        free(buf);
1083
1084result:
1085        if (type >= FTRACE_README_END)
1086                return false;
1087
1088        return ftrace_readme_table[type].avail;
1089}
1090
1091bool probe_type_is_available(enum probe_type type)
1092{
1093        if (type >= PROBE_TYPE_END)
1094                return false;
1095        else if (type == PROBE_TYPE_X)
1096                return scan_ftrace_readme(FTRACE_README_PROBE_TYPE_X);
1097
1098        return true;
1099}
1100
1101bool kretprobe_offset_is_supported(void)
1102{
1103        return scan_ftrace_readme(FTRACE_README_KRETPROBE_OFFSET);
1104}
1105
1106bool uprobe_ref_ctr_is_supported(void)
1107{
1108        return scan_ftrace_readme(FTRACE_README_UPROBE_REF_CTR);
1109}
1110
1111bool user_access_is_supported(void)
1112{
1113        return scan_ftrace_readme(FTRACE_README_USER_ACCESS);
1114}
1115
1116bool multiprobe_event_is_supported(void)
1117{
1118        return scan_ftrace_readme(FTRACE_README_MULTIPROBE_EVENT);
1119}
1120
1121bool immediate_value_is_supported(void)
1122{
1123        return scan_ftrace_readme(FTRACE_README_IMMEDIATE_VALUE);
1124}
1125