// SPDX-License-Identifier: GPL-2.0 /* * build-id.c * * build-id support * * Copyright (C) 2009, 2010 Red Hat Inc. * Copyright (C) 2009, 2010 Arnaldo Carvalho de Melo */ #include "util.h" #include #include #include #include #include #include "build-id.h" #include "event.h" #include "namespaces.h" #include "map.h" #include "symbol.h" #include "thread.h" #include #include "debug.h" #include "session.h" #include "tool.h" #include "header.h" #include "vdso.h" #include "path.h" #include "probe-file.h" #include "strlist.h" #include #include static bool no_buildid_cache; int build_id__mark_dso_hit(struct perf_tool *tool __maybe_unused, union perf_event *event, struct perf_sample *sample, struct evsel *evsel __maybe_unused, struct machine *machine) { struct addr_location al; struct thread *thread = machine__findnew_thread(machine, sample->pid, sample->tid); if (thread == NULL) { pr_err("problem processing %d event, skipping it.\n", event->header.type); return -1; } if (thread__find_map(thread, sample->cpumode, sample->ip, &al)) al.map->dso->hit = 1; thread__put(thread); return 0; } static int perf_event__exit_del_thread(struct perf_tool *tool __maybe_unused, union perf_event *event, struct perf_sample *sample __maybe_unused, struct machine *machine) { struct thread *thread = machine__findnew_thread(machine, event->fork.pid, event->fork.tid); dump_printf("(%d:%d):(%d:%d)\n", event->fork.pid, event->fork.tid, event->fork.ppid, event->fork.ptid); if (thread) { machine__remove_thread(machine, thread); thread__put(thread); } return 0; } struct perf_tool build_id__mark_dso_hit_ops = { .sample = build_id__mark_dso_hit, .mmap = perf_event__process_mmap, .mmap2 = perf_event__process_mmap2, .fork = perf_event__process_fork, .exit = perf_event__exit_del_thread, .attr = perf_event__process_attr, .build_id = perf_event__process_build_id, .ordered_events = true, }; int build_id__sprintf(const u8 *build_id, int len, char *bf) { char *bid = bf; const u8 *raw = build_id; int i; for (i = 0; i < len; ++i) { sprintf(bid, "%02x", *raw); ++raw; bid += 2; } return (bid - bf) + 1; } int sysfs__sprintf_build_id(const char *root_dir, char *sbuild_id) { char notes[PATH_MAX]; u8 build_id[BUILD_ID_SIZE]; int ret; if (!root_dir) root_dir = ""; scnprintf(notes, sizeof(notes), "%s/sys/kernel/notes", root_dir); ret = sysfs__read_build_id(notes, build_id, sizeof(build_id)); if (ret < 0) return ret; return build_id__sprintf(build_id, sizeof(build_id), sbuild_id); } int filename__sprintf_build_id(const char *pathname, char *sbuild_id) { u8 build_id[BUILD_ID_SIZE]; int ret; ret = filename__read_build_id(pathname, build_id, sizeof(build_id)); if (ret < 0) return ret; else if (ret != sizeof(build_id)) return -EINVAL; return build_id__sprintf(build_id, sizeof(build_id), sbuild_id); } /* asnprintf consolidates asprintf and snprintf */ static int asnprintf(char **strp, size_t size, const char *fmt, ...) { va_list ap; int ret; if (!strp) return -EINVAL; va_start(ap, fmt); if (*strp) ret = vsnprintf(*strp, size, fmt, ap); else ret = vasprintf(strp, fmt, ap); va_end(ap); return ret; } char *build_id_cache__kallsyms_path(const char *sbuild_id, char *bf, size_t size) { bool retry_old = true; snprintf(bf, size, "%s/%s/%s/kallsyms", buildid_dir, DSO__NAME_KALLSYMS, sbuild_id); retry: if (!access(bf, F_OK)) return bf; if (retry_old) { /* Try old style kallsyms cache */ snprintf(bf, size, "%s/%s/%s", buildid_dir, DSO__NAME_KALLSYMS, sbuild_id); retry_old = false; goto retry; } return NULL; } char *build_id_cache__linkname(const char *sbuild_id, char *bf, size_t size) { char *tmp = bf; int ret = asnprintf(&bf, size, "%s/.build-id/%.2s/%s", buildid_dir, sbuild_id, sbuild_id + 2); if (ret < 0 || (tmp && size < (unsigned int)ret)) return NULL; return bf; } /* The caller is responsible to free the returned buffer. */ char *build_id_cache__origname(const char *sbuild_id) { char *linkname; char buf[PATH_MAX]; char *ret = NULL, *p; size_t offs = 5; /* == strlen("../..") */ ssize_t len; linkname = build_id_cache__linkname(sbuild_id, NULL, 0); if (!linkname) return NULL; len = readlink(linkname, buf, sizeof(buf) - 1); if (len <= 0) goto out; buf[len] = '\0'; /* The link should be "../../" */ p = strrchr(buf, '/'); /* Cut off the "/" */ if (p && (p > buf + offs)) { *p = '\0'; if (buf[offs + 1] == '[') offs++; /* * This is a DSO name, like [kernel.kallsyms]. * Skip the first '/', since this is not the * cache of a regular file. */ ret = strdup(buf + offs); /* Skip "../..[/]" */ } out: free(linkname); return ret; } /* Check if the given build_id cache is valid on current running system */ static bool build_id_cache__valid_id(char *sbuild_id) { char real_sbuild_id[SBUILD_ID_SIZE] = ""; char *pathname; int ret = 0; bool result = false; pathname = build_id_cache__origname(sbuild_id); if (!pathname) return false; if (!strcmp(pathname, DSO__NAME_KALLSYMS)) ret = sysfs__sprintf_build_id("/", real_sbuild_id); else if (pathname[0] == '/') ret = filename__sprintf_build_id(pathname, real_sbuild_id); else ret = -EINVAL; /* Should we support other special DSO cache? */ if (ret >= 0) result = (strcmp(sbuild_id, real_sbuild_id) == 0); free(pathname); return result; } static const char *build_id_cache__basename(bool is_kallsyms, bool is_vdso, bool is_debug) { return is_kallsyms ? "kallsyms" : (is_vdso ? "vdso" : (is_debug ? "debug" : "elf")); } char *dso__build_id_filename(const struct dso *dso, char *bf, size_t size, bool is_debug) { bool is_kallsyms = dso__is_kallsyms((struct dso *)dso); bool is_vdso = dso__is_vdso((struct dso *)dso); char sbuild_id[SBUILD_ID_SIZE]; char *linkname; bool alloc = (bf == NULL); int ret; if (!dso->has_build_id) return NULL; build_id__sprintf(dso->build_id, sizeof(dso->build_id), sbuild_id); linkname = build_id_cache__linkname(sbuild_id, NULL, 0); if (!linkname) return NULL; /* Check if old style build_id cache */ if (is_regular_file(linkname)) ret = asnprintf(&bf, size, "%s", linkname); else ret = asnprintf(&bf, size, "%s/%s", linkname, build_id_cache__basename(is_kallsyms, is_vdso, is_debug)); if (ret < 0 || (!alloc && size < (unsigned int)ret)) bf = NULL; free(linkname); return bf; } #define dsos__for_each_with_build_id(pos, head) \ list_for_each_entry(pos, head, node) \ if (!pos->has_build_id) \ continue; \ else static int write_buildid(const char *name, size_t name_len, u8 *build_id, pid_t pid, u16 misc, struct feat_fd *fd) { int err; struct perf_record_header_build_id b; size_t len; len = name_len + 1; len = PERF_ALIGN(len, NAME_ALIGN); memset(&b, 0, sizeof(b)); memcpy(&b.build_id, build_id, BUILD_ID_SIZE); b.pid = pid; b.header.misc = misc; b.header.size = sizeof(b) + len; err = do_write(fd, &b, sizeof(b)); if (err < 0) return err; return write_padded(fd, name, name_len + 1, len); } static int machine__write_buildid_table(struct machine *machine, struct feat_fd *fd) { int err = 0; struct dso *pos; u16 kmisc = PERF_RECORD_MISC_KERNEL, umisc = PERF_RECORD_MISC_USER; if (!machine__is_host(machine)) { kmisc = PERF_RECORD_MISC_GUEST_KERNEL; umisc = PERF_RECORD_MISC_GUEST_USER; } dsos__for_each_with_build_id(pos, &machine->dsos.head) { const char *name; size_t name_len; bool in_kernel = false; if (!pos->hit && !dso__is_vdso(pos)) continue; if (dso__is_vdso(pos)) { name = pos->short_name; name_len = pos->short_name_len; } else if (dso__is_kcore(pos)) { name = machine->mmap_name; name_len = strlen(name); } else { name = pos->long_name; name_len = pos->long_name_len; } in_kernel = pos->kernel || is_kernel_module(name, PERF_RECORD_MISC_CPUMODE_UNKNOWN); err = write_buildid(name, name_len, pos->build_id, machine->pid, in_kernel ? kmisc : umisc, fd); if (err) break; } return err; } int perf_session__write_buildid_table(struct perf_session *session, struct feat_fd *fd) { struct rb_node *nd; int err = machine__write_buildid_table(&session->machines.host, fd); if (err) return err; for (nd = rb_first_cached(&session->machines.guests); nd; nd = rb_next(nd)) { struct machine *pos = rb_entry(nd, struct machine, rb_node); err = machine__write_buildid_table(pos, fd); if (err) break; } return err; } static int __dsos__hit_all(struct list_head *head) { struct dso *pos; list_for_each_entry(pos, head, node) pos->hit = true; return 0; } static int machine__hit_all_dsos(struct machine *machine) { return __dsos__hit_all(&machine->dsos.head); } int dsos__hit_all(struct perf_session *session) { struct rb_node *nd; int err; err = machine__hit_all_dsos(&session->machines.host); if (err) return err; for (nd = rb_first_cached(&session->machines.guests); nd; nd = rb_next(nd)) { struct machine *pos = rb_entry(nd, struct machine, rb_node); err = machine__hit_all_dsos(pos); if (err) return err; } return 0; } void disable_buildid_cache(void) { no_buildid_cache = true; } static bool lsdir_bid_head_filter(const char *name __maybe_unused, struct dirent *d) { return (strlen(d->d_name) == 2) && isxdigit(d->d_name[0]) && isxdigit(d->d_name[1]); } static bool lsdir_bid_tail_filter(const char *name __maybe_unused, struct dirent *d) { int i = 0; while (isxdigit(d->d_name[i]) && i < SBUILD_ID_SIZE - 3) i++; return (i == SBUILD_ID_SIZE - 3) && (d->d_name[i] == '\0'); } struct strlist *build_id_cache__list_all(bool validonly) { struct strlist *toplist, *linklist = NULL, *bidlist; struct str_node *nd, *nd2; char *topdir, *linkdir = NULL; char sbuild_id[SBUILD_ID_SIZE]; /* for filename__ functions */ if (validonly) symbol__init(NULL); /* Open the top-level directory */ if (asprintf(&topdir, "%s/.build-id/", buildid_dir) < 0) return NULL; bidlist = strlist__new(NULL, NULL); if (!bidlist) goto out; toplist = lsdir(topdir, lsdir_bid_head_filter); if (!toplist) { pr_debug("Error in lsdir(%s): %d\n", topdir, errno); /* If there is no buildid cache, return an empty list */ if (errno == ENOENT) goto out; goto err_out; } strlist__for_each_entry(nd, toplist) { if (asprintf(&linkdir, "%s/%s", topdir, nd->s) < 0) goto err_out; /* Open the lower-level directory */ linklist = lsdir(linkdir, lsdir_bid_tail_filter); if (!linklist) { pr_debug("Error in lsdir(%s): %d\n", linkdir, errno); goto err_out; } strlist__for_each_entry(nd2, linklist) { if (snprintf(sbuild_id, SBUILD_ID_SIZE, "%s%s", nd->s, nd2->s) != SBUILD_ID_SIZE - 1) goto err_out; if (validonly && !build_id_cache__valid_id(sbuild_id)) continue; if (strlist__add(bidlist, sbuild_id) < 0) goto err_out; } strlist__delete(linklist); zfree(&linkdir); } out_free: strlist__delete(toplist); out: free(topdir); return bidlist; err_out: strlist__delete(linklist); zfree(&linkdir); strlist__delete(bidlist); bidlist = NULL; goto out_free; } static bool str_is_build_id(const char *maybe_sbuild_id, size_t len) { size_t i; for (i = 0; i < len; i++) { if (!isxdigit(maybe_sbuild_id[i])) return false; } return true; } /* Return the valid complete build-id */ char *build_id_cache__complement(const char *incomplete_sbuild_id) { struct strlist *bidlist; struct str_node *nd, *cand = NULL; char *sbuild_id = NULL; size_t len = strlen(incomplete_sbuild_id); if (len >= SBUILD_ID_SIZE || !str_is_build_id(incomplete_sbuild_id, len)) return NULL; bidlist = build_id_cache__list_all(true); if (!bidlist) return NULL; strlist__for_each_entry(nd, bidlist) { if (strncmp(nd->s, incomplete_sbuild_id, len) != 0) continue; if (cand) { /* Error: There are more than 2 candidates. */ cand = NULL; break; } cand = nd; } if (cand) sbuild_id = strdup(cand->s); strlist__delete(bidlist); return sbuild_id; } char *build_id_cache__cachedir(const char *sbuild_id, const char *name, struct nsinfo *nsi, bool is_kallsyms, bool is_vdso) { char *realname = (char *)name, *filename; bool slash = is_kallsyms || is_vdso; if (!slash) { realname = nsinfo__realpath(name, nsi); if (!realname) return NULL; } if (asprintf(&filename, "%s%s%s%s%s", buildid_dir, slash ? "/" : "", is_vdso ? DSO__NAME_VDSO : realname, sbuild_id ? "/" : "", sbuild_id ?: "") < 0) filename = NULL; if (!slash) free(realname); return filename; } int build_id_cache__list_build_ids(const char *pathname, struct nsinfo *nsi, struct strlist **result) { char *dir_name; int ret = 0; dir_name = build_id_cache__cachedir(NULL, pathname, nsi, false, false); if (!dir_name) return -ENOMEM; *result = lsdir(dir_name, lsdir_no_dot_filter); if (!*result) ret = -errno; free(dir_name); return ret; } #if defined(HAVE_LIBELF_SUPPORT) && defined(HAVE_GELF_GETNOTE_SUPPORT) static int build_id_cache__add_sdt_cache(const char *sbuild_id, const char *realname, struct nsinfo *nsi) { struct probe_cache *cache; int ret; struct nscookie nsc; cache = probe_cache__new(sbuild_id, nsi); if (!cache) return -1; nsinfo__mountns_enter(nsi, &nsc); ret = probe_cache__scan_sdt(cache, realname); nsinfo__mountns_exit(&nsc); if (ret >= 0) { pr_debug4("Found %d SDTs in %s\n", ret, realname); if (probe_cache__commit(cache) < 0) ret = -1; } probe_cache__delete(cache); return ret; } #else #define build_id_cache__add_sdt_cache(sbuild_id, realname, nsi) (0) #endif static char *build_id_cache__find_debug(const char *sbuild_id, struct nsinfo *nsi) { char *realname = NULL; char *debugfile; struct nscookie nsc; size_t len = 0; debugfile = calloc(1, PATH_MAX); if (!debugfile) goto out; len = __symbol__join_symfs(debugfile, PATH_MAX, "/usr/lib/debug/.build-id/"); snprintf(debugfile + len, PATH_MAX - len, "%.2s/%s.debug", sbuild_id, sbuild_id + 2); nsinfo__mountns_enter(nsi, &nsc); realname = realpath(debugfile, NULL); if (realname && access(realname, R_OK)) zfree(&realname); nsinfo__mountns_exit(&nsc); out: free(debugfile); return realname; } int build_id_cache__add_s(const char *sbuild_id, const char *name, struct nsinfo *nsi, bool is_kallsyms, bool is_vdso) { const size_t size = PATH_MAX; char *realname = NULL, *filename = NULL, *dir_name = NULL, *linkname = zalloc(size), *tmp; char *debugfile = NULL; int err = -1; if (!is_kallsyms) { if (!is_vdso) realname = nsinfo__realpath(name, nsi); else realname = realpath(name, NULL); if (!realname) goto out_free; } dir_name = build_id_cache__cachedir(sbuild_id, name, nsi, is_kallsyms, is_vdso); if (!dir_name) goto out_free; /* Remove old style build-id cache */ if (is_regular_file(dir_name)) if (unlink(dir_name)) goto out_free; if (mkdir_p(dir_name, 0755)) goto out_free; /* Save the allocated buildid dirname */ if (asprintf(&filename, "%s/%s", dir_name, build_id_cache__basename(is_kallsyms, is_vdso, false)) < 0) { filename = NULL; goto out_free; } if (access(filename, F_OK)) { if (is_kallsyms) { if (copyfile("/proc/kallsyms", filename)) goto out_free; } else if (nsi && nsi->need_setns) { if (copyfile_ns(name, filename, nsi)) goto out_free; } else if (link(realname, filename) && errno != EEXIST && copyfile(name, filename)) goto out_free; } /* Some binaries are stripped, but have .debug files with their symbol * table. Check to see if we can locate one of those, since the elf * file itself may not be very useful to users of our tools without a * symtab. */ if (!is_kallsyms && !is_vdso && strncmp(".ko", name + strlen(name) - 3, 3)) { debugfile = build_id_cache__find_debug(sbuild_id, nsi); if (debugfile) { zfree(&filename); if (asprintf(&filename, "%s/%s", dir_name, build_id_cache__basename(false, false, true)) < 0) { filename = NULL; goto out_free; } if (access(filename, F_OK)) { if (nsi && nsi->need_setns) { if (copyfile_ns(debugfile, filename, nsi)) goto out_free; } else if (link(debugfile, filename) && errno != EEXIST && copyfile(debugfile, filename)) goto out_free; } } } if (!build_id_cache__linkname(sbuild_id, linkname, size)) goto out_free; tmp = strrchr(linkname, '/'); *tmp = '\0'; if (access(linkname, X_OK) && mkdir_p(linkname, 0755)) goto out_free; *tmp = '/'; tmp = dir_name + strlen(buildid_dir) - 5; memcpy(tmp, "../..", 5); if (symlink(tmp, linkname) == 0) err = 0; /* Update SDT cache : error is just warned */ if (realname && build_id_cache__add_sdt_cache(sbuild_id, realname, nsi) < 0) pr_debug4("Failed to update/scan SDT cache for %s\n", realname); out_free: if (!is_kallsyms) free(realname); free(filename); free(debugfile); free(dir_name); free(linkname); return err; } static int build_id_cache__add_b(const u8 *build_id, size_t build_id_size, const char *name, struct nsinfo *nsi, bool is_kallsyms, bool is_vdso) { char sbuild_id[SBUILD_ID_SIZE]; build_id__sprintf(build_id, build_id_size, sbuild_id); return build_id_cache__add_s(sbuild_id, name, nsi, is_kallsyms, is_vdso); } bool build_id_cache__cached(const char *sbuild_id) { bool ret = false; char *filename = build_id_cache__linkname(sbuild_id, NULL, 0); if (filename && !access(filename, F_OK)) ret = true; free(filename); return ret; } int build_id_cache__remove_s(const char *sbuild_id) { const size_t size = PATH_MAX; char *filename = zalloc(size), *linkname = zalloc(size), *tmp; int err = -1; if (filename == NULL || linkname == NULL) goto out_free; if (!build_id_cache__linkname(sbuild_id, linkname, size)) goto out_free; if (access(linkname, F_OK)) goto out_free; if (readlink(linkname, filename, size - 1) < 0) goto out_free; if (unlink(linkname)) goto out_free; /* * Since the link is relative, we must make it absolute: */ tmp = strrchr(linkname, '/') + 1; snprintf(tmp, size - (tmp - linkname), "%s", filename); if (rm_rf(linkname)) goto out_free; err = 0; out_free: free(filename); free(linkname); return err; } static int dso__cache_build_id(struct dso *dso, struct machine *machine) { bool is_kallsyms = dso__is_kallsyms(dso); bool is_vdso = dso__is_vdso(dso); const char *name = dso->long_name; if (dso__is_kcore(dso)) { is_kallsyms = true; name = machine->mmap_name; } return build_id_cache__add_b(dso->build_id, sizeof(dso->build_id), name, dso->nsinfo, is_kallsyms, is_vdso); } static int __dsos__cache_build_ids(struct list_head *head, struct machine *machine) { struct dso *pos; int err = 0; dsos__for_each_with_build_id(pos, head) if (dso__cache_build_id(pos, machine)) err = -1; return err; } static int machine__cache_build_ids(struct machine *machine) { return __dsos__cache_build_ids(&machine->dsos.head, machine); } int perf_session__cache_build_ids(struct perf_session *session) { struct rb_node *nd; int ret; if (no_buildid_cache) return 0; if (mkdir(buildid_dir, 0755) != 0 && errno != EEXIST) return -1; ret = machine__cache_build_ids(&session->machines.host); for (nd = rb_first_cached(&session->machines.guests); nd; nd = rb_next(nd)) { struct machine *pos = rb_entry(nd, struct machine, rb_node); ret |= machine__cache_build_ids(pos); } return ret ? -1 : 0; } static bool machine__read_build_ids(struct machine *machine, bool with_hits) { return __dsos__read_build_ids(&machine->dsos.head, with_hits); } bool perf_session__read_build_ids(struct perf_session *session, bool with_hits) { struct rb_node *nd; bool ret = machine__read_build_ids(&session->machines.host, with_hits); for (nd = rb_first_cached(&session->machines.guests); nd; nd = rb_next(nd)) { struct machine *pos = rb_entry(nd, struct machine, rb_node); ret |= machine__read_build_ids(pos, with_hits); } return ret; }