tools/perf/util/build-id.c

   1 /*
   2  * build-id.c
   3  *
   4  * build-id support
   5  *
   6  * Copyright (C) 2009, 2010 Red Hat Inc.
   7  * Copyright (C) 2009, 2010 Arnaldo Carvalho de Melo <acme@redhat.com>
   8  */
   9 #include "util.h"
  10 #include <stdio.h>
  11 #include "build-id.h"
  12 #include "event.h"
  13 #include "symbol.h"
  14 #include <linux/kernel.h>
  15 #include "debug.h"
  16 #include "session.h"
  17 #include "tool.h"
  18 #include "header.h"
  19 #include "vdso.h"
  20
  21
  22 static bool no_buildid_cache;
  23
  24 int build_id__mark_dso_hit(struct perf_tool *tool __maybe_unused,
  25                            union perf_event *event,
  26                            struct perf_sample *sample,
  27                            struct perf_evsel *evsel __maybe_unused,
  28                            struct machine *machine)
  29 {
  30         struct addr_location al;
  31         u8 cpumode = event->header.misc & PERF_RECORD_MISC_CPUMODE_MASK;
  32         struct thread *thread = machine__findnew_thread(machine, sample->pid,
  33                                                         sample->tid);
  34
  35         if (thread == NULL) {
  36                 pr_err("problem processing %d event, skipping it.\n",
  37                         event->header.type);
  38                 return -1;
  39         }
  40
  41         thread__find_addr_map(thread, cpumode, MAP__FUNCTION, sample->ip, &al);
  42
  43         if (al.map != NULL)
  44                 al.map->dso->hit = 1;
  45
  46         return 0;
  47 }
  48
  49 static int perf_event__exit_del_thread(struct perf_tool *tool __maybe_unused,
  50                                        union perf_event *event,
  51                                        struct perf_sample *sample
  52                                        __maybe_unused,
  53                                        struct machine *machine)
  54 {
  55         struct thread *thread = machine__findnew_thread(machine,
  56                                                         event->fork.pid,
  57                                                         event->fork.tid);
  58
  59         dump_printf("(%d:%d):(%d:%d)\n", event->fork.pid, event->fork.tid,
  60                     event->fork.ppid, event->fork.ptid);
  61
  62         if (thread) {
  63                 rb_erase(&thread->rb_node, &machine->threads);
  64                 machine->last_match = NULL;
  65                 thread__delete(thread);
  66         }
  67
  68         return 0;
  69 }
  70
  71 struct perf_tool build_id__mark_dso_hit_ops = {
  72         .sample = build_id__mark_dso_hit,
  73         .mmap   = perf_event__process_mmap,
  74         .mmap2  = perf_event__process_mmap2,
  75         .fork   = perf_event__process_fork,
  76         .exit   = perf_event__exit_del_thread,
  77         .attr            = perf_event__process_attr,
  78         .build_id        = perf_event__process_build_id,
  79 };
  80
  81 int build_id__sprintf(const u8 *build_id, int len, char *bf)
  82 {
  83         char *bid = bf;
  84         const u8 *raw = build_id;
  85         int i;
  86
  87         for (i = 0; i < len; ++i) {
  88                 sprintf(bid, "%02x", *raw);
  89                 ++raw;
  90                 bid += 2;
  91         }
  92
  93         return raw - build_id;
  94 }
  95
  96 char *dso__build_id_filename(const struct dso *dso, char *bf, size_t size)
  97 {
  98         char build_id_hex[BUILD_ID_SIZE * 2 + 1];
  99
 100         if (!dso->has_build_id)
 101                 return NULL;
 102
 103         build_id__sprintf(dso->build_id, sizeof(dso->build_id), build_id_hex);
 104         if (bf == NULL) {
 105                 if (asprintf(&bf, "%s/.build-id/%.2s/%s", buildid_dir,
 106                              build_id_hex, build_id_hex + 2) < 0)
 107                         return NULL;
 108         } else
 109                 snprintf(bf, size, "%s/.build-id/%.2s/%s", buildid_dir,
 110                          build_id_hex, build_id_hex + 2);
 111         return bf;
 112 }
 113
 114 #define dsos__for_each_with_build_id(pos, head) \
 115         list_for_each_entry(pos, head, node)    \
 116                 if (!pos->has_build_id)         \
 117                         continue;               \
 118                 else
 119
 120 static int write_buildid(const char *name, size_t name_len, u8 *build_id,
 121                          pid_t pid, u16 misc, int fd)
 122 {
 123         int err;
 124         struct build_id_event b;
 125         size_t len;
 126
 127         len = name_len + 1;
 128         len = PERF_ALIGN(len, NAME_ALIGN);
 129
 130         memset(&b, 0, sizeof(b));
 131         memcpy(&b.build_id, build_id, BUILD_ID_SIZE);
 132         b.pid = pid;
 133         b.header.misc = misc;
 134         b.header.size = sizeof(b) + len;
 135
 136         err = writen(fd, &b, sizeof(b));
 137         if (err < 0)
 138                 return err;
 139
 140         return write_padded(fd, name, name_len + 1, len);
 141 }
 142
 143 static int __dsos__write_buildid_table(struct list_head *head,
 144                                        struct machine *machine,
 145                                        pid_t pid, u16 misc, int fd)
 146 {
 147         char nm[PATH_MAX];
 148         struct dso *pos;
 149
 150         dsos__for_each_with_build_id(pos, head) {
 151                 int err;
 152                 const char *name;
 153                 size_t name_len;
 154
 155                 if (!pos->hit)
 156                         continue;
 157
 158                 if (dso__is_vdso(pos)) {
 159                         name = pos->short_name;
 160                         name_len = pos->short_name_len + 1;
 161                 } else if (dso__is_kcore(pos)) {
 162                         machine__mmap_name(machine, nm, sizeof(nm));
 163                         name = nm;
 164                         name_len = strlen(nm) + 1;
 165                 } else {
 166                         name = pos->long_name;
 167                         name_len = pos->long_name_len + 1;
 168                 }
 169
 170                 err = write_buildid(name, name_len, pos->build_id,
 171                                     pid, misc, fd);
 172                 if (err)
 173                         return err;
 174         }
 175
 176         return 0;
 177 }
 178
 179 static int machine__write_buildid_table(struct machine *machine, int fd)
 180 {
 181         int err;
 182         u16 kmisc = PERF_RECORD_MISC_KERNEL,
 183             umisc = PERF_RECORD_MISC_USER;
 184
 185         if (!machine__is_host(machine)) {
 186                 kmisc = PERF_RECORD_MISC_GUEST_KERNEL;
 187                 umisc = PERF_RECORD_MISC_GUEST_USER;
 188         }
 189
 190         err = __dsos__write_buildid_table(&machine->kernel_dsos.head, machine,
 191                                           machine->pid, kmisc, fd);
 192         if (err == 0)
 193                 err = __dsos__write_buildid_table(&machine->user_dsos.head,
 194                                                   machine, machine->pid, umisc,
 195                                                   fd);
 196         return err;
 197 }
 198
 199 int perf_session__write_buildid_table(struct perf_session *session, int fd)
 200 {
 201         struct rb_node *nd;
 202         int err = machine__write_buildid_table(&session->machines.host, fd);
 203
 204         if (err)
 205                 return err;
 206
 207         for (nd = rb_first(&session->machines.guests); nd; nd = rb_next(nd)) {
 208                 struct machine *pos = rb_entry(nd, struct machine, rb_node);
 209                 err = machine__write_buildid_table(pos, fd);
 210                 if (err)
 211                         break;
 212         }
 213         return err;
 214 }
 215
 216 static int __dsos__hit_all(struct list_head *head)
 217 {
 218         struct dso *pos;
 219
 220         list_for_each_entry(pos, head, node)
 221                 pos->hit = true;
 222
 223         return 0;
 224 }
 225
 226 static int machine__hit_all_dsos(struct machine *machine)
 227 {
 228         int err;
 229
 230         err = __dsos__hit_all(&machine->kernel_dsos.head);
 231         if (err)
 232                 return err;
 233
 234         return __dsos__hit_all(&machine->user_dsos.head);
 235 }
 236
 237 int dsos__hit_all(struct perf_session *session)
 238 {
 239         struct rb_node *nd;
 240         int err;
 241
 242         err = machine__hit_all_dsos(&session->machines.host);
 243         if (err)
 244                 return err;
 245
 246         for (nd = rb_first(&session->machines.guests); nd; nd = rb_next(nd)) {
 247                 struct machine *pos = rb_entry(nd, struct machine, rb_node);
 248
 249                 err = machine__hit_all_dsos(pos);
 250                 if (err)
 251                         return err;
 252         }
 253
 254         return 0;
 255 }
 256
 257 void disable_buildid_cache(void)
 258 {
 259         no_buildid_cache = true;
 260 }
 261
 262 int build_id_cache__add_s(const char *sbuild_id, const char *debugdir,
 263                           const char *name, bool is_kallsyms, bool is_vdso)
 264 {
 265         const size_t size = PATH_MAX;
 266         char *realname, *filename = zalloc(size),
 267              *linkname = zalloc(size), *targetname;
 268         int len, err = -1;
 269         bool slash = is_kallsyms || is_vdso;
 270
 271         if (is_kallsyms) {
 272                 if (symbol_conf.kptr_restrict) {
 273                         pr_debug("Not caching a kptr_restrict'ed /proc/kallsyms\n");
 274                         err = 0;
 275                         goto out_free;
 276                 }
 277                 realname = (char *) name;
 278         } else
 279                 realname = realpath(name, NULL);
 280
 281         if (realname == NULL || filename == NULL || linkname == NULL)
 282                 goto out_free;
 283
 284         len = scnprintf(filename, size, "%s%s%s",
 285                        debugdir, slash ? "/" : "",
 286                        is_vdso ? DSO__NAME_VDSO : realname);
 287         if (mkdir_p(filename, 0755))
 288                 goto out_free;
 289
 290         snprintf(filename + len, size - len, "/%s", sbuild_id);
 291
 292         if (access(filename, F_OK)) {
 293                 if (is_kallsyms) {
 294                          if (copyfile("/proc/kallsyms", filename))
 295                                 goto out_free;
 296                 } else if (link(realname, filename) && copyfile(name, filename))
 297                         goto out_free;
 298         }
 299
 300         len = scnprintf(linkname, size, "%s/.build-id/%.2s",
 301                        debugdir, sbuild_id);
 302
 303         if (access(linkname, X_OK) && mkdir_p(linkname, 0755))
 304                 goto out_free;
 305
 306         snprintf(linkname + len, size - len, "/%s", sbuild_id + 2);
 307         targetname = filename + strlen(debugdir) - 5;
 308         memcpy(targetname, "../..", 5);
 309
 310         if (symlink(targetname, linkname) == 0)
 311                 err = 0;
 312 out_free:
 313         if (!is_kallsyms)
 314                 free(realname);
 315         free(filename);
 316         free(linkname);
 317         return err;
 318 }
 319
 320 static int build_id_cache__add_b(const u8 *build_id, size_t build_id_size,
 321                                  const char *name, const char *debugdir,
 322                                  bool is_kallsyms, bool is_vdso)
 323 {
 324         char sbuild_id[BUILD_ID_SIZE * 2 + 1];
 325
 326         build_id__sprintf(build_id, build_id_size, sbuild_id);
 327
 328         return build_id_cache__add_s(sbuild_id, debugdir, name,
 329                                      is_kallsyms, is_vdso);
 330 }
 331
 332 int build_id_cache__remove_s(const char *sbuild_id, const char *debugdir)
 333 {
 334         const size_t size = PATH_MAX;
 335         char *filename = zalloc(size),
 336              *linkname = zalloc(size);
 337         int err = -1;
 338
 339         if (filename == NULL || linkname == NULL)
 340                 goto out_free;
 341
 342         snprintf(linkname, size, "%s/.build-id/%.2s/%s",
 343                  debugdir, sbuild_id, sbuild_id + 2);
 344
 345         if (access(linkname, F_OK))
 346                 goto out_free;
 347
 348         if (readlink(linkname, filename, size - 1) < 0)
 349                 goto out_free;
 350
 351         if (unlink(linkname))
 352                 goto out_free;
 353
 354         /*
 355          * Since the link is relative, we must make it absolute:
 356          */
 357         snprintf(linkname, size, "%s/.build-id/%.2s/%s",
 358                  debugdir, sbuild_id, filename);
 359
 360         if (unlink(linkname))
 361                 goto out_free;
 362
 363         err = 0;
 364 out_free:
 365         free(filename);
 366         free(linkname);
 367         return err;
 368 }
 369
 370 static int dso__cache_build_id(struct dso *dso, struct machine *machine,
 371                                const char *debugdir)
 372 {
 373         bool is_kallsyms = dso->kernel && dso->long_name[0] != '/';
 374         bool is_vdso = dso__is_vdso(dso);
 375         const char *name = dso->long_name;
 376         char nm[PATH_MAX];
 377
 378         if (dso__is_kcore(dso)) {
 379                 is_kallsyms = true;
 380                 machine__mmap_name(machine, nm, sizeof(nm));
 381                 name = nm;
 382         }
 383         return build_id_cache__add_b(dso->build_id, sizeof(dso->build_id), name,
 384                                      debugdir, is_kallsyms, is_vdso);
 385 }
 386
 387 static int __dsos__cache_build_ids(struct list_head *head,
 388                                    struct machine *machine, const char *debugdir)
 389 {
 390         struct dso *pos;
 391         int err = 0;
 392
 393         dsos__for_each_with_build_id(pos, head)
 394                 if (dso__cache_build_id(pos, machine, debugdir))
 395                         err = -1;
 396
 397         return err;
 398 }
 399
 400 static int machine__cache_build_ids(struct machine *machine, const char *debugdir)
 401 {
 402         int ret = __dsos__cache_build_ids(&machine->kernel_dsos.head, machine,
 403                                           debugdir);
 404         ret |= __dsos__cache_build_ids(&machine->user_dsos.head, machine,
 405                                        debugdir);
 406         return ret;
 407 }
 408
 409 int perf_session__cache_build_ids(struct perf_session *session)
 410 {
 411         struct rb_node *nd;
 412         int ret;
 413
 414         if (no_buildid_cache)
 415                 return 0;
 416
 417         if (mkdir(buildid_dir, 0755) != 0 && errno != EEXIST)
 418                 return -1;
 419
 420         ret = machine__cache_build_ids(&session->machines.host, buildid_dir);
 421
 422         for (nd = rb_first(&session->machines.guests); nd; nd = rb_next(nd)) {
 423                 struct machine *pos = rb_entry(nd, struct machine, rb_node);
 424                 ret |= machine__cache_build_ids(pos, buildid_dir);
 425         }
 426         return ret ? -1 : 0;
 427 }
 428
 429 static bool machine__read_build_ids(struct machine *machine, bool with_hits)
 430 {
 431         bool ret;
 432
 433         ret  = __dsos__read_build_ids(&machine->kernel_dsos.head, with_hits);
 434         ret |= __dsos__read_build_ids(&machine->user_dsos.head, with_hits);
 435         return ret;
 436 }
 437
 438 bool perf_session__read_build_ids(struct perf_session *session, bool with_hits)
 439 {
 440         struct rb_node *nd;
 441         bool ret = machine__read_build_ids(&session->machines.host, with_hits);
 442
 443         for (nd = rb_first(&session->machines.guests); nd; nd = rb_next(nd)) {
 444                 struct machine *pos = rb_entry(nd, struct machine, rb_node);
 445                 ret |= machine__read_build_ids(pos, with_hits);
 446         }
 447
 448         return ret;
 449 }