diff options
Diffstat (limited to 'tools/perf')
| -rw-r--r-- | tools/perf/Documentation/perf-buildid-cache.txt | 13 | ||||
| -rw-r--r-- | tools/perf/builtin-buildid-cache.c | 148 | ||||
| -rw-r--r-- | tools/perf/util/symbol-elf.c | 366 | ||||
| -rw-r--r-- | tools/perf/util/symbol-minimal.c | 6 | ||||
| -rw-r--r-- | tools/perf/util/symbol.c | 41 | ||||
| -rw-r--r-- | tools/perf/util/symbol.h | 3 |
6 files changed, 576 insertions, 1 deletions
diff --git a/tools/perf/Documentation/perf-buildid-cache.txt b/tools/perf/Documentation/perf-buildid-cache.txt index e9a8349a7172..fd77d81ea748 100644 --- a/tools/perf/Documentation/perf-buildid-cache.txt +++ b/tools/perf/Documentation/perf-buildid-cache.txt @@ -21,6 +21,19 @@ OPTIONS -a:: --add=:: Add specified file to the cache. +-k:: +--kcore:: + Add specified kcore file to the cache. For the current host that is + /proc/kcore which requires root permissions to read. Be aware that + running 'perf buildid-cache' as root may update root's build-id cache + not the user's. Use the -v option to see where the file is created. + Note that the copied file contains only code sections not the whole core + image. Note also that files "kallsyms" and "modules" must also be in the + same directory and are also copied. All 3 files are created with read + permissions for root only. kcore will not be added if there is already a + kcore in the cache (with the same build-id) that has the same modules at + the same addresses. Use the -v option to see if a copy of kcore is + actually made. -r:: --remove=:: Remove specified file from the cache. diff --git a/tools/perf/builtin-buildid-cache.c b/tools/perf/builtin-buildid-cache.c index c96c8fa38243..8140b7b249fa 100644 --- a/tools/perf/builtin-buildid-cache.c +++ b/tools/perf/builtin-buildid-cache.c @@ -6,6 +6,11 @@ * Copyright (C) 2010, Red Hat Inc. * Copyright (C) 2010, Arnaldo Carvalho de Melo <acme@redhat.com> */ +#include <sys/types.h> +#include <sys/time.h> +#include <time.h> +#include <dirent.h> +#include <unistd.h> #include "builtin.h" #include "perf.h" #include "util/cache.h" @@ -17,6 +22,140 @@ #include "util/session.h" #include "util/symbol.h" +static int build_id_cache__kcore_buildid(const char *proc_dir, char *sbuildid) +{ + char root_dir[PATH_MAX]; + char notes[PATH_MAX]; + u8 build_id[BUILD_ID_SIZE]; + char *p; + + strlcpy(root_dir, proc_dir, sizeof(root_dir)); + + p = strrchr(root_dir, '/'); + if (!p) + return -1; + *p = '\0'; + + scnprintf(notes, sizeof(notes), "%s/sys/kernel/notes", root_dir); + + if (sysfs__read_build_id(notes, build_id, sizeof(build_id))) + return -1; + + build_id__sprintf(build_id, sizeof(build_id), sbuildid); + + return 0; +} + +static int build_id_cache__kcore_dir(char *dir, size_t sz) +{ + struct timeval tv; + struct tm tm; + char dt[32]; + + if (gettimeofday(&tv, NULL) || !localtime_r(&tv.tv_sec, &tm)) + return -1; + + if (!strftime(dt, sizeof(dt), "%Y%m%d%H%M%S", &tm)) + return -1; + + scnprintf(dir, sz, "%s%02u", dt, (unsigned)tv.tv_usec / 10000); + + return 0; +} + +static int build_id_cache__kcore_existing(const char *from_dir, char *to_dir, + size_t to_dir_sz) +{ + char from[PATH_MAX]; + char to[PATH_MAX]; + struct dirent *dent; + int ret = -1; + DIR *d; + + d = opendir(to_dir); + if (!d) + return -1; + + scnprintf(from, sizeof(from), "%s/modules", from_dir); + + while (1) { + dent = readdir(d); + if (!dent) + break; + if (dent->d_type != DT_DIR) + continue; + scnprintf(to, sizeof(to), "%s/%s/modules", to_dir, + dent->d_name); + if (!compare_proc_modules(from, to)) { + scnprintf(to, sizeof(to), "%s/%s", to_dir, + dent->d_name); + strlcpy(to_dir, to, to_dir_sz); + ret = 0; + break; + } + } + + closedir(d); + + return ret; +} + +static int build_id_cache__add_kcore(const char *filename, const char *debugdir) +{ + char dir[32], sbuildid[BUILD_ID_SIZE * 2 + 1]; + char from_dir[PATH_MAX], to_dir[PATH_MAX]; + char *p; + + strlcpy(from_dir, filename, sizeof(from_dir)); + + p = strrchr(from_dir, '/'); + if (!p || strcmp(p + 1, "kcore")) + return -1; + *p = '\0'; + + if (build_id_cache__kcore_buildid(from_dir, sbuildid)) + return -1; + + scnprintf(to_dir, sizeof(to_dir), "%s/[kernel.kcore]/%s", + debugdir, sbuildid); + + if (!build_id_cache__kcore_existing(from_dir, to_dir, sizeof(to_dir))) { + pr_debug("same kcore found in %s\n", to_dir); + return 0; + } + + if (build_id_cache__kcore_dir(dir, sizeof(dir))) + return -1; + + scnprintf(to_dir, sizeof(to_dir), "%s/[kernel.kcore]/%s/%s", + debugdir, sbuildid, dir); + + if (mkdir_p(to_dir, 0755)) + return -1; + + if (kcore_copy(from_dir, to_dir)) { + /* Remove YYYYmmddHHMMSShh directory */ + if (!rmdir(to_dir)) { + p = strrchr(to_dir, '/'); + if (p) + *p = '\0'; + /* Try to remove buildid directory */ + if (!rmdir(to_dir)) { + p = strrchr(to_dir, '/'); + if (p) + *p = '\0'; + /* Try to remove [kernel.kcore] directory */ + rmdir(to_dir); + } + } + return -1; + } + + pr_debug("kcore added to build-id cache directory %s\n", to_dir); + + return 0; +} + static int build_id_cache__add_file(const char *filename, const char *debugdir) { char sbuild_id[BUILD_ID_SIZE * 2 + 1]; @@ -130,11 +269,14 @@ int cmd_buildid_cache(int argc, const char **argv, char const *add_name_list_str = NULL, *remove_name_list_str = NULL, *missing_filename = NULL, - *update_name_list_str = NULL; + *update_name_list_str = NULL, + *kcore_filename; const struct option buildid_cache_options[] = { OPT_STRING('a', "add", &add_name_list_str, "file list", "file(s) to add"), + OPT_STRING('k', "kcore", &kcore_filename, + "file", "kcore file to add"), OPT_STRING('r', "remove", &remove_name_list_str, "file list", "file(s) to remove"), OPT_STRING('M', "missing", &missing_filename, "file", @@ -217,5 +359,9 @@ int cmd_buildid_cache(int argc, const char **argv, } } + if (kcore_filename && + build_id_cache__add_kcore(kcore_filename, debugdir)) + pr_warning("Couldn't add %s\n", kcore_filename); + return ret; } diff --git a/tools/perf/util/symbol-elf.c b/tools/perf/util/symbol-elf.c index 499c71d30225..d6b8af3ce344 100644 --- a/tools/perf/util/symbol-elf.c +++ b/tools/perf/util/symbol-elf.c @@ -1202,6 +1202,372 @@ static off_t kcore__write(struct kcore *kcore) return elf_update(kcore->elf, ELF_C_WRITE); } +struct phdr_data { + off_t offset; + u64 addr; + u64 len; +}; + +struct kcore_copy_info { + u64 stext; + u64 etext; + u64 first_symbol; + u64 last_symbol; + u64 first_module; + u64 last_module_symbol; + struct phdr_data kernel_map; + struct phdr_data modules_map; +}; + +static int kcore_copy__process_kallsyms(void *arg, const char *name, char type, + u64 start) +{ + struct kcore_copy_info *kci = arg; + + if (!symbol_type__is_a(type, MAP__FUNCTION)) + return 0; + + if (strchr(name, '[')) { + if (start > kci->last_module_symbol) + kci->last_module_symbol = start; + return 0; + } + + if (!kci->first_symbol || start < kci->first_symbol) + kci->first_symbol = start; + + if (!kci->last_symbol || start > kci->last_symbol) + kci->last_symbol = start; + + if (!strcmp(name, "_stext")) { + kci->stext = start; + return 0; + } + + if (!strcmp(name, "_etext")) { + kci->etext = start; + return 0; + } + + return 0; +} + +static int kcore_copy__parse_kallsyms(struct kcore_copy_info *kci, + const char *dir) +{ + char kallsyms_filename[PATH_MAX]; + + scnprintf(kallsyms_filename, PATH_MAX, "%s/kallsyms", dir); + + if (symbol__restricted_filename(kallsyms_filename, "/proc/kallsyms")) + return -1; + + if (kallsyms__parse(kallsyms_filename, kci, + kcore_copy__process_kallsyms) < 0) + return -1; + + return 0; +} + +static int kcore_copy__process_modules(void *arg, + const char *name __maybe_unused, + u64 start) +{ + struct kcore_copy_info *kci = arg; + + if (!kci->first_module || start < kci->first_module) + kci->first_module = start; + + return 0; +} + +static int kcore_copy__parse_modules(struct kcore_copy_info *kci, + const char *dir) +{ + char modules_filename[PATH_MAX]; + + scnprintf(modules_filename, PATH_MAX, "%s/modules", dir); + + if (symbol__restricted_filename(modules_filename, "/proc/modules")) + return -1; + + if (modules__parse(modules_filename, kci, + kcore_copy__process_modules) < 0) + return -1; + + return 0; +} + +static void kcore_copy__map(struct phdr_data *p, u64 start, u64 end, u64 pgoff, + u64 s, u64 e) +{ + if (p->addr || s < start || s >= end) + return; + + p->addr = s; + p->offset = (s - start) + pgoff; + p->len = e < end ? e - s : end - s; +} + +static int kcore_copy__read_map(u64 start, u64 len, u64 pgoff, void *data) +{ + struct kcore_copy_info *kci = data; + u64 end = start + len; + + kcore_copy__map(&kci->kernel_map, start, end, pgoff, kci->stext, + kci->etext); + + kcore_copy__map(&kci->modules_map, start, end, pgoff, kci->first_module, + kci->last_module_symbol); + + return 0; +} + +static int kcore_copy__read_maps(struct kcore_copy_info *kci, Elf *elf) +{ + if (elf_read_maps(elf, true, kcore_copy__read_map, kci) < 0) + return -1; + + return 0; +} + +static int kcore_copy__calc_maps(struct kcore_copy_info *kci, const char *dir, + Elf *elf) +{ + if (kcore_copy__parse_kallsyms(kci, dir)) + return -1; + + if (kcore_copy__parse_modules(kci, dir)) + return -1; + + if (kci->stext) + kci->stext = round_down(kci->stext, page_size); + else + kci->stext = round_down(kci->first_symbol, page_size); + + if (kci->etext) { + kci->etext = round_up(kci->etext, page_size); + } else if (kci->last_symbol) { + kci->etext = round_up(kci->last_symbol, page_size); + kci->etext += page_size; + } + + kci->first_module = round_down(kci->first_module, page_size); + + if (kci->last_module_symbol) { + kci->last_module_symbol = round_up(kci->last_module_symbol, + page_size); + kci->last_module_symbol += page_size; + } + + if (!kci->stext || !kci->etext) + return -1; + + if (kci->first_module && !kci->last_module_symbol) + return -1; + + return kcore_copy__read_maps(kci, elf); +} + +static int kcore_copy__copy_file(const char *from_dir, const char *to_dir, + const char *name) +{ + char from_filename[PATH_MAX]; + char to_filename[PATH_MAX]; + + scnprintf(from_filename, PATH_MAX, "%s/%s", from_dir, name); + scnprintf(to_filename, PATH_MAX, "%s/%s", to_dir, name); + + return copyfile_mode(from_filename, to_filename, 0400); +} + +static int kcore_copy__unlink(const char *dir, const char *name) +{ + char filename[PATH_MAX]; + + scnprintf(filename, PATH_MAX, "%s/%s", dir, name); + + return unlink(filename); +} + +static int kcore_copy__compare_fds(int from, int to) +{ + char *buf_from; + char *buf_to; + ssize_t ret; + size_t len; + int err = -1; + + buf_from = malloc(page_size); + buf_to = malloc(page_size); + if (!buf_from || !buf_to) + goto out; + + while (1) { + /* Use read because mmap won't work on proc files */ + ret = read(from, buf_from, page_size); + if (ret < 0) + goto out; + + if (!ret) + break; + + len = ret; + + if (readn(to, buf_to, len) != (int)len) + goto out; + + if (memcmp(buf_from, buf_to, len)) + goto out; + } + + err = 0; +out: + free(buf_to); + free(buf_from); + return err; +} + +static int kcore_copy__compare_files(const char *from_filename, + const char *to_filename) +{ + int from, to, err = -1; + + from = open(from_filename, O_RDONLY); + if (from < 0) + return -1; + + to = open(to_filename, O_RDONLY); + if (to < 0) + goto out_close_from; + + err = kcore_copy__compare_fds(from, to); + + close(to); +out_close_from: + close(from); + return err; +} + +static int kcore_copy__compare_file(const char *from_dir, const char *to_dir, + const char *name) +{ + char from_filename[PATH_MAX]; + char to_filename[PATH_MAX]; + + scnprintf(from_filename, PATH_MAX, "%s/%s", from_dir, name); + scnprintf(to_filename, PATH_MAX, "%s/%s", to_dir, name); + + return kcore_copy__compare_files(from_filename, to_filename); +} + +/** + * kcore_copy - copy kallsyms, modules and kcore from one directory to another. + * @from_dir: from directory + * @to_dir: to directory + * + * This function copies kallsyms, modules and kcore files from one directory to + * another. kallsyms and modules are copied entirely. Only code segments are + * copied from kcore. It is assumed that two segments suffice: one for the + * kernel proper and one for all the modules. The code segments are determined + * from kallsyms and modules files. The kernel map starts at _stext or the + * lowest function symbol, and ends at _etext or the highest function symbol. + * The module map starts at the lowest module address and ends at the highest + * module symbol. Start addresses are rounded down to the nearest page. End + * addresses are rounded up to the nearest page. An extra page is added to the + * highest kernel symbol and highest module symbol to, hopefully, encompass that + * symbol too. Because it contains only code sections, the resulting kcore is + * unusual. One significant peculiarity is that the mapping (start -> pgoff) + * is not the same for the kernel map and the modules map. That happens because + * the data is copied adjacently whereas the original kcore has gaps. Finally, + * kallsyms and modules files are compared with their copies to check that + * modules have not been loaded or unloaded while the copies were taking place. + * + * Return: %0 on success, %-1 on failure. + */ +int kcore_copy(const char *from_dir, const char *to_dir) +{ + struct kcore kcore; + struct kcore extract; + size_t count = 2; + int idx = 0, err = -1; + off_t offset = page_size, sz, modules_offset = 0; + struct kcore_copy_info kci = { .stext = 0, }; + char kcore_filename[PATH_MAX]; + char extract_filename[PATH_MAX]; + + if (kcore_copy__copy_file(from_dir, to_dir, "kallsyms")) + return -1; + + if (kcore_copy__copy_file(from_dir, to_dir, "modules")) + goto out_unlink_kallsyms; + + scnprintf(kcore_filename, PATH_MAX, "%s/kcore", from_dir); + scnprintf(extract_filename, PATH_MAX, "%s/kcore", to_dir); + + if (kcore__open(&kcore, kcore_filename)) + goto out_unlink_modules; + + if (kcore_copy__calc_maps(&kci, from_dir, kcore.elf)) + goto out_kcore_close; + + if (kcore__init(&extract, extract_filename, kcore.elfclass, false)) + goto out_kcore_close; + + if (!kci.modules_map.addr) + count -= 1; + + if (kcore__copy_hdr(&kcore, &extract, count)) + goto out_extract_close; + + if (kcore__add_phdr(&extract, idx++, offset, kci.kernel_map.addr, + kci.kernel_map.len)) + goto out_extract_close; + + if (kci.modules_map.addr) { + modules_offset = offset + kci.kernel_map.len; + if (kcore__add_phdr(&extract, idx, modules_offset, + kci.modules_map.addr, kci.modules_map.len)) + goto out_extract_close; + } + + sz = kcore__write(&extract); + if (sz < 0 || sz > offset) + goto out_extract_close; + + if (copy_bytes(kcore.fd, kci.kernel_map.offset, extract.fd, offset, + kci.kernel_map.len)) + goto out_extract_close; + + if (modules_offset && copy_bytes(kcore.fd, kci.modules_map.offset, + extract.fd, modules_offset, + kci.modules_map.len)) + goto out_extract_close; + + if (kcore_copy__compare_file(from_dir, to_dir, "modules")) + goto out_extract_close; + + if (kcore_copy__compare_file(from_dir, to_dir, "kallsyms")) + goto out_extract_close; + + err = 0; + +out_extract_close: + kcore__close(&extract); + if (err) + unlink(extract_filename); +out_kcore_close: + kcore__close(&kcore); +out_unlink_modules: + if (err) + kcore_copy__unlink(to_dir, "modules"); +out_unlink_kallsyms: + if (err) + kcore_copy__unlink(to_dir, "kallsyms"); + + return err; +} + int kcore_extract__create(struct kcore_extract *kce) { struct kcore kcore; diff --git a/tools/perf/util/symbol-minimal.c b/tools/perf/util/symbol-minimal.c index 928556d2508f..2d2dd0532b5a 100644 --- a/tools/perf/util/symbol-minimal.c +++ b/tools/perf/util/symbol-minimal.c @@ -317,6 +317,12 @@ void kcore_extract__delete(struct kcore_extract *kce __maybe_unused) { } +int kcore_copy(const char *from_dir __maybe_unused, + const char *to_dir __maybe_unused) +{ + return -1; +} + void symbol__elf_init(void) { } diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c index 76a9e933a7a5..b66c1eefc313 100644 --- a/tools/perf/util/symbol.c +++ b/tools/perf/util/symbol.c @@ -893,6 +893,47 @@ static int read_proc_modules(const char *filename, struct rb_root *modules) return 0; } +int compare_proc_modules(const char *from, const char *to) +{ + struct rb_root from_modules = RB_ROOT; + struct rb_root to_modules = RB_ROOT; + struct rb_node *from_node, *to_node; + struct module_info *from_m, *to_m; + int ret = -1; + + if (read_proc_modules(from, &from_modules)) + return -1; + + if (read_proc_modules(to, &to_modules)) + goto out_delete_from; + + from_node = rb_first(&from_modules); + to_node = rb_first(&to_modules); + while (from_node) { + if (!to_node) + break; + + from_m = rb_entry(from_node, struct module_info, rb_node); + to_m = rb_entry(to_node, struct module_info, rb_node); + + if (from_m->start != to_m->start || + strcmp(from_m->name, to_m->name)) + break; + + from_node = rb_next(from_node); + to_node = rb_next(to_node); + } + + if (!from_node && !to_node) + ret = 0; + + delete_modules(&to_modules); +out_delete_from: + delete_modules(&from_modules); + + return ret; +} + static int do_validate_kcore_modules(const char *filename, struct map *map, struct map_groups *kmaps) { diff --git a/tools/perf/util/symbol.h b/tools/perf/util/symbol.h index fb107e13e925..07de8fea2f48 100644 --- a/tools/perf/util/symbol.h +++ b/tools/perf/util/symbol.h @@ -270,4 +270,7 @@ struct kcore_extract { int kcore_extract__create(struct kcore_extract *kce); void kcore_extract__delete(struct kcore_extract *kce); +int kcore_copy(const char *from_dir, const char *to_dir); +int compare_proc_modules(const char *from, const char *to); + #endif /* __PERF_SYMBOL */ |