#include <dirent.h> #include <errno.h> #include <stdlib.h> #include <stdio.h> #include <string.h> #include <sys/types.h> #include <sys/stat.h> #include <sys/param.h> #include <fcntl.h> #include <unistd.h> #include <inttypes.h> #include "build-id.h" #include "util.h" #include "debug.h" #include "symbol.h" #include "strlist.h" #include <libelf.h> #include <gelf.h> #include <elf.h> #include <limits.h> #include <sys/utsname.h> #ifndef KSYM_NAME_LEN #define KSYM_NAME_LEN 256 #endif #ifndef NT_GNU_BUILD_ID #define NT_GNU_BUILD_ID 3 #endif static bool dso__build_id_equal(const struct dso *dso, u8 *build_id); static int elf_read_build_id(Elf *elf, void *bf, size_t size); static void dsos__add(struct list_head *head, struct dso *dso); static struct map *map__new2(u64 start, struct dso *dso, enum map_type type); static int dso__load_kernel_sym(struct dso *dso, struct map *map, symbol_filter_t filter); static int dso__load_guest_kernel_sym(struct dso *dso, struct map *map, symbol_filter_t filter); static int vmlinux_path__nr_entries; static char **vmlinux_path; struct symbol_conf symbol_conf = { .exclude_other = true, .use_modules = true, .try_vmlinux_path = true, .annotate_src = true, .symfs = "", }; int dso__name_len(const struct dso *dso) { if (!dso) return strlen("[unknown]"); if (verbose) return dso->long_name_len; return dso->short_name_len; } bool dso__loaded(const struct dso *dso, enum map_type type) { return dso->loaded & (1 << type); } bool dso__sorted_by_name(const struct dso *dso, enum map_type type) { return dso->sorted_by_name & (1 << type); } static void dso__set_sorted_by_name(struct dso *dso, enum map_type type) { dso->sorted_by_name |= (1 << type); } bool symbol_type__is_a(char symbol_type, enum map_type map_type) { symbol_type = toupper(symbol_type); switch (map_type) { case MAP__FUNCTION: return symbol_type == 'T' || symbol_type == 'W'; case MAP__VARIABLE: return symbol_type == 'D'; default: return false; } } static int prefix_underscores_count(const char *str) { const char *tail = str; while (*tail == '_') tail++; return tail - str; } #define SYMBOL_A 0 #define SYMBOL_B 1 static int choose_best_symbol(struct symbol *syma, struct symbol *symb) { s64 a; s64 b; /* Prefer a symbol with non zero length */ a = syma->end - syma->start; b = symb->end - symb->start; if ((b == 0) && (a > 0)) return SYMBOL_A; else if ((a == 0) && (b > 0)) return SYMBOL_B; /* Prefer a non weak symbol over a weak one */ a = syma->binding == STB_WEAK; b = symb->binding == STB_WEAK; if (b && !a) return SYMBOL_A; if (a && !b) return SYMBOL_B; /* Prefer a global symbol over a non global one */ a = syma->binding == STB_GLOBAL; b = symb->binding == STB_GLOBAL; if (a && !b) return SYMBOL_A; if (b && !a) return SYMBOL_B; /* Prefer a symbol with less underscores */ a = prefix_underscores_count(syma->name); b = prefix_underscores_count(symb->name); if (b > a) return SYMBOL_A; else if (a > b) return SYMBOL_B; /* If all else fails, choose the symbol with the longest name */ if (strlen(syma->name) >= strlen(symb->name)) return SYMBOL_A; else return SYMBOL_B; } static void symbols__fixup_duplicate(struct rb_root *symbols) { struct rb_node *nd; struct symbol *curr, *next; nd = rb_first(symbols); while (nd) { curr = rb_entry(nd, struct symbol, rb_node); again: nd = rb_next(&curr->rb_node); next = rb_entry(nd, struct symbol, rb_node); if (!nd) break; if (curr->start != next->start) continue; if (choose_best_symbol(curr, next) == SYMBOL_A) { rb_erase(&next->rb_node, symbols); goto again; } else { nd = rb_next(&curr->rb_node); rb_erase(&curr->rb_node, symbols); } } } static void symbols__fixup_end(struct rb_root *symbols) { struct rb_node *nd, *prevnd = rb_first(symbols); struct symbol *curr, *prev; if (prevnd == NULL) return; curr = rb_entry(prevnd, struct symbol, rb_node); for (nd = rb_next(prevnd); nd; nd = rb_next(nd)) { prev = curr; curr = rb_entry(nd, struct symbol, rb_node); if (prev->end == prev->start && prev->end != curr->start) prev->end = curr->start - 1; } /* Last entry */ if (curr->end == curr->start) curr->end = roundup(curr->start, 4096); } static void __map_groups__fixup_end(struct map_groups *mg, enum map_type type) { struct map *prev, *curr; struct rb_node *nd, *prevnd = rb_first(&mg->maps[type]); if (prevnd == NULL) return; curr = rb_entry(prevnd, struct map, rb_node); for (nd = rb_next(prevnd); nd; nd = rb_next(nd)) { prev = curr; curr = rb_entry(nd, struct map, rb_node); prev->end = curr->start - 1; } /* * We still haven't the actual symbols, so guess the * last map final address. */ curr->end = ~0ULL; } static void map_groups__fixup_end(struct map_groups *mg) { int i; for (i = 0; i < MAP__NR_TYPES; ++i) __map_groups__fixup_end(mg, i); } static struct symbol *symbol__new(u64 start, u64 len, u8 binding, const char *name) { size_t namelen = strlen(name) + 1; struct symbol *sym = calloc(1, (symbol_conf.priv_size + sizeof(*sym) + namelen)); if (sym == NULL) return NULL; if (symbol_conf.priv_size) sym = ((void *)sym) + symbol_conf.priv_size; sym->start = start; sym->end = len ? start + len - 1 : start; sym->binding = binding; sym->namelen = namelen - 1; pr_debug4("%s: %s %#" PRIx64 "-%#" PRIx64 "\n", __func__, name, start, sym->end); memcpy(sym->name, name, namelen); return sym; } void symbol__delete(struct symbol *sym) { free(((void *)sym) - symbol_conf.priv_size); } static size_t symbol__fprintf(struct symbol *sym, FILE *fp) { return fprintf(fp, " %" PRIx64 "-%" PRIx64 " %c %s\n", sym->start, sym->end, sym->binding == STB_GLOBAL ? 'g' : sym->binding == STB_LOCAL ? 'l' : 'w', sym->name); } size_t symbol__fprintf_symname_offs(const struct symbol *sym, const struct addr_location *al, FILE *fp) { unsigned long offset; size_t length; if (sym && sym->name) { length = fprintf(fp, "%s", sym->name); if (al) { offset = al->addr - sym->start; length += fprintf(fp, "+0x%lx", offset); } return length; } else return fprintf(fp, "[unknown]"); } size_t symbol__fprintf_symname(const struct symbol *sym, FILE *fp) { return symbol__fprintf_symname_offs(sym, NULL, fp); } void dso__set_long_name(struct dso *dso, char *name) { if (name == NULL) return; dso->long_name = name; dso->long_name_len = strlen(name); } static void dso__set_short_name(struct dso *dso, const char *name) { if (name == NULL) return; dso->short_name = name; dso->short_name_len = strlen(name); } static void dso__set_basename(struct dso *dso) { dso__set_short_name(dso, basename(dso->long_name)); } struct dso *dso__new(const char *name) { struct dso *dso = calloc(1, sizeof(*dso) + strlen(name) + 1); if (dso != NULL) { int i; strcpy(dso->name, name); dso__set_long_name(dso, dso->name); dso__set_short_name(dso, dso->name); for (i = 0; i < MAP__NR_TYPES; ++i) dso->symbols[i] = dso->symbol_names[i] = RB_ROOT; dso->symtab_type = SYMTAB__NOT_FOUND; dso->loaded = 0; dso->sorted_by_name = 0; dso->has_build_id = 0; dso->kernel = DSO_TYPE_USER; INIT_LIST_HEAD(&dso->node); } return dso; } static void symbols__delete(struct rb_root *symbols) { struct symbol *pos; struct rb_node *next = rb_first(symbols); while (next) { pos = rb_entry(next, struct symbol, rb_node); next = rb_next(&pos->rb_node); rb_erase(&pos->rb_node, symbols); symbol__delete(pos); } } void dso__delete(struct dso *dso) { int i; for (i = 0; i < MAP__NR_TYPES; ++i) symbols__delete(&dso->symbols[i]); if (dso->sname_alloc) free((char *)dso->short_name); if (dso->lname_alloc) free(dso->long_name); free(dso); } void dso__set_build_id(struct dso *dso, void *build_id) { memcpy(dso->build_id, build_id, sizeof(dso->build_id)); dso->has_build_id = 1; } static void symbols__insert(struct rb_root *symbols, struct symbol *sym) { struct rb_node **p = &symbols->rb_node; struct rb_node *parent = NULL; const u64 ip = sym->start; struct symbol *s; while (*p != NULL) { parent = *p; s = rb_entry(parent, struct symbol, rb_node); if (ip < s->start) p = &(*p)->rb_left; else p = &(*p)->rb_right; } rb_link_node(&sym->rb_node, parent, p); rb_insert_color(&sym->rb_node, symbols); } static struct symbol *symbols__find(struct rb_root *symbols, u64 ip) { struct rb_node *n; if (symbols == NULL) return NULL; n = symbols->rb_node; while (n) { struct symbol *s = rb_entry(n, struct symbol, rb_node); if (ip < s->start) n = n->rb_left; else if (ip > s->end) n = n->rb_right; else return s; } return NULL; } struct symbol_name_rb_node { struct rb_node rb_node; struct symbol sym; }; static void symbols__insert_by_name(struct rb_root *symbols, struct symbol *sym) { struct rb_node **p = &symbols->rb_node; struct rb_node *parent = NULL; struct symbol_name_rb_node *symn, *s; symn = container_of(sym, struct symbol_name_rb_node, sym); while (*p != NULL) { parent = *p; s = rb_entry(parent, struct symbol_name_rb_node, rb_node); if (strcmp(sym->name, s->sym.name) < 0) p = &(*p)->rb_left; else p = &(*p)->rb_right; } rb_link_node(&symn->rb_node, parent, p); rb_insert_color(&symn->rb_node, symbols); } static void symbols__sort_by_name(struct rb_root *symbols, struct rb_root *source) { struct rb_node *nd; for (nd = rb_first(source); nd; nd = rb_next(nd)) { struct symbol *pos = rb_entry(nd, struct symbol, rb_node); symbols__insert_by_name(symbols, pos); } } static struct symbol *symbols__find_by_name(struct rb_root *symbols, const char *name) { struct rb_node *n; if (symbols == NULL) return NULL; n = symbols->rb_node; while (n) { struct symbol_name_rb_node *s; int cmp; s = rb_entry(n, struct symbol_name_rb_node, rb_node); cmp = strcmp(name, s->sym.name); if (cmp < 0) n = n->rb_left; else if (cmp > 0) n = n->rb_right; else return &s->sym; } return NULL; } struct symbol *dso__find_symbol(struct dso *dso, enum map_type type, u64 addr) { return symbols__find(&dso->symbols[type], addr); } struct symbol *dso__find_symbol_by_name(struct dso *dso, enum map_type type, const char *name) { return symbols__find_by_name(&dso->symbol_names[type], name); } void dso__sort_by_name(struct dso *dso, enum map_type type) { dso__set_sorted_by_name(dso, type); return symbols__sort_by_name(&dso->symbol_names[type], &dso->symbols[type]); } 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 raw - build_id; } size_t dso__fprintf_buildid(struct dso *dso, FILE *fp) { char sbuild_id[BUILD_ID_SIZE * 2 + 1]; build_id__sprintf(dso->build_id, sizeof(dso->build_id), sbuild_id); return fprintf(fp, "%s", sbuild_id); } size_t dso__fprintf_symbols_by_name(struct dso *dso, enum map_type type, FILE *fp) { size_t ret = 0; struct rb_node *nd; struct symbol_name_rb_node *pos; for (nd = rb_first(&dso->symbol_names[type]); nd; nd = rb_next(nd)) { pos = rb_entry(nd, struct symbol_name_rb_node, rb_node); fprintf(fp, "%s\n", pos->sym.name); } return ret; } size_t dso__fprintf(struct dso *dso, enum map_type type, FILE *fp) { struct rb_node *nd; size_t ret = fprintf(fp, "dso: %s (", dso->short_name); if (dso->short_name != dso->long_name) ret += fprintf(fp, "%s, ", dso->long_name); ret += fprintf(fp, "%s, %sloaded, ", map_type__name[type], dso->loaded ? "" : "NOT "); ret += dso__fprintf_buildid(dso, fp); ret += fprintf(fp, ")\n"); for (nd = rb_first(&dso->symbols[type]); nd; nd = rb_next(nd)) { struct symbol *pos = rb_entry(nd, struct symbol, rb_node); ret += symbol__fprintf(pos, fp); } return ret; } int kallsyms__parse(const char *filename, void *arg, int (*process_symbol)(void *arg, const char *name, char type, u64 start, u64 end)) { char *line = NULL; size_t n; int err = -1; FILE *file = fopen(filename, "r"); if (file == NULL) goto out_failure; err = 0; while (!feof(file)) { u64 start; int line_len, len; char symbol_type; char *symbol_name; line_len = getline(&line, &n, file); if (line_len < 0 || !line) break; line[--line_len] = '\0'; /* \n */ len = hex2u64(line, &start); len++; if (len + 2 >= line_len) continue; symbol_type = line[len]; len += 2; symbol_name = line + len; len = line_len - len; if (len >= KSYM_NAME_LEN) { err = -1; break; } /* * module symbols are not sorted so we add all * symbols with zero length and rely on * symbols__fixup_end() to fix it up. */ err = process_symbol(arg, symbol_name, symbol_type, start, start); if (err) break; } free(line); fclose(file); return err; out_failure: return -1; } struct process_kallsyms_args { struct map *map; struct dso *dso; }; static u8 kallsyms2elf_type(char type) { if (type == 'W') return STB_WEAK; return isupper(type) ? STB_GLOBAL : STB_LOCAL; } static int map__process_kallsym_symbol(void *arg, const char *name, char type, u64 start, u64 end) { struct symbol *sym; struct process_kallsyms_args *a = arg; struct rb_root *root = &a->dso->symbols[a->map->type]; if (!symbol_type__is_a(type, a->map->type)) return 0; sym = symbol__new(start, end - start + 1, kallsyms2elf_type(type), name); if (sym == NULL) return -ENOMEM; /* * We will pass the symbols to the filter later, in * map__split_kallsyms, when we have split the maps per module */ symbols__insert(root, sym); return 0; } /* * Loads the function entries in /proc/kallsyms into kernel_map->dso, * so that we can in the next step set the symbol ->end address and then * call kernel_maps__split_kallsyms. */ static int dso__load_all_kallsyms(struct dso *dso, const char *filename, struct map *map) { struct process_kallsyms_args args = { .map = map, .dso = dso, }; return kallsyms__parse(filename, &args, map__process_kallsym_symbol); } /* * Split the symbols into maps, making sure there are no overlaps, i.e. the * kernel range is broken in several maps, named [kernel].N, as we don't have * the original ELF section names vmlinux have. */ static int dso__split_kallsyms(struct dso *dso, struct map *map, symbol_filter_t filter) { struct map_groups *kmaps = map__kmap(map)->kmaps; struct machine *machine = kmaps->machine; struct map *curr_map = map; struct symbol *pos; int count = 0, moved = 0; struct rb_root *root = &dso->symbols[map->type]; struct rb_node *next = rb_first(root); int kernel_range = 0; while (next) { char *module; pos = rb_entry(next, struct symbol, rb_node); next = rb_next(&pos->rb_node); module = strchr(pos->name, '\t'); if (module) { if (!symbol_conf.use_modules) goto discard_symbol; *module++ = '\0'; if (strcmp(curr_map->dso->short_name, module)) { if (curr_map != map && dso->kernel == DSO_TYPE_GUEST_KERNEL && machine__is_default_guest(machine)) { /* * We assume all symbols of a module are * continuous in * kallsyms, so curr_map * points to a module and all its * symbols are in its kmap. Mark it as * loaded. */ dso__set_loaded(curr_map->dso, curr_map->type); } curr_map = map_groups__find_by_name(kmaps, map->type, module); if (curr_map == NULL) { pr_debug("%s/proc/{kallsyms,modules} " "inconsistency while looking " "for \"%s\" module!\n", machine->root_dir, module); curr_map = map; goto discard_symbol; } if (curr_map->dso->loaded && !machine__is_default_guest(machine)) goto discard_symbol; } /* * So that we look just like we get from .ko files, * i.e. not prelinked, relative to map->start. */ pos->start = curr_map->map_ip(curr_map, pos->start); pos->end = curr_map->map_ip(curr_map, pos->end); } else if (curr_map != map) { char dso_name[PATH_MAX]; struct dso *ndso; if (count == 0) { curr_map = map; goto filter_symbol; } if (dso->kernel == DSO_TYPE_GUEST_KERNEL) snprintf(dso_name, sizeof(dso_name), "[guest.kernel].%d", kernel_range++); else snprintf(dso_name, sizeof(dso_name), "[kernel].%d", kernel_range++); ndso = dso__new(dso_name); if (ndso == NULL) return -1; ndso->kernel = dso->kernel; curr_map = map__new2(pos->start, ndso, map->type); if (curr_map == NULL) { dso__delete(ndso); return -1; } curr_map->map_ip = curr_map->unmap_ip = identity__map_ip; map_groups__insert(kmaps, curr_map); ++kernel_range; } filter_symbol: if (filter && filter(curr_map, pos)) { discard_symbol: rb_erase(&pos->rb_node, root); symbol__delete(pos); } else { if (curr_map != map) { rb_erase(&pos->rb_node, root); symbols__insert(&curr_map->dso->symbols[curr_map->type], pos); ++moved; } else ++count; } } if (curr_map != map && dso->kernel == DSO_TYPE_GUEST_KERNEL && machine__is_default_guest(kmaps->machine)) { dso__set_loaded(curr_map->dso, curr_map->type); } return count + moved; } static bool symbol__restricted_filename(const char *filename, const char *restricted_filename) { bool restricted = false; if (symbol_conf.kptr_restrict) { char *r = realpath(filename, NULL); if (r != NULL) { restricted = strcmp(r, restricted_filename) == 0; free(r); return restricted; } } return restricted; } int dso__load_kallsyms(struct dso *dso, const char *filename, struct map *map, symbol_filter_t filter) { if (symbol__restricted_filename(filename, "/proc/kallsyms")) return -1; if (dso__load_all_kallsyms(dso, filename, map) < 0) return -1; symbols__fixup_duplicate(&dso->symbols[map->type]); symbols__fixup_end(&dso->symbols[map->type]); if (dso->kernel == DSO_TYPE_GUEST_KERNEL) dso->symtab_type = SYMTAB__GUEST_KALLSYMS; else dso->symtab_type = SYMTAB__KALLSYMS; return dso__split_kallsyms(dso, map, filter); } static int dso__load_perf_map(struct dso *dso, struct map *map, symbol_filter_t filter) { char *line = NULL; size_t n; FILE *file; int nr_syms = 0; file = fopen(dso->long_name, "r"); if (file == NULL) goto out_failure; while (!feof(file)) { u64 start, size; struct symbol *sym; int line_len, len; line_len = getline(&line, &n, file); if (line_len < 0) break; if (!line) goto out_failure; line[--line_len] = '\0'; /* \n */ len = hex2u64(line, &start); len++; if (len + 2 >= line_len) continue; len += hex2u64(line + len, &size); len++; if (len + 2 >= line_len) continue; sym = symbol__new(start, size, STB_GLOBAL, line + len); if (sym == NULL) goto out_delete_line; if (filter && filter(map, sym)) symbol__delete(sym); else { symbols__insert(&dso->symbols[map->type], sym); nr_syms++; } } free(line); fclose(file); return nr_syms; out_delete_line: free(line); out_failure: return -1; } /** * elf_symtab__for_each_symbol - iterate thru all the symbols * * @syms: struct elf_symtab instance to iterate * @idx: uint32_t idx * @sym: GElf_Sym iterator */ #define elf_symtab__for_each_symbol(syms, nr_syms, idx, sym) \ for (idx = 0, gelf_getsym(syms, idx, &sym);\ idx < nr_syms; \ idx++, gelf_getsym(syms, idx, &sym)) static inline uint8_t elf_sym__type(const GElf_Sym *sym) { return GELF_ST_TYPE(sym->st_info); } static inline int elf_sym__is_function(const GElf_Sym *sym) { return elf_sym__type(sym) == STT_FUNC && sym->st_name != 0 && sym->st_shndx != SHN_UNDEF; } static inline bool elf_sym__is_object(const GElf_Sym *sym) { return elf_sym__type(sym) == STT_OBJECT && sym->st_name != 0 && sym->st_shndx != SHN_UNDEF; } static inline int elf_sym__is_label(const GElf_Sym *sym) { return elf_sym__type(sym) == STT_NOTYPE && sym->st_name != 0 && sym->st_shndx != SHN_UNDEF && sym->st_shndx != SHN_ABS; } static inline const char *elf_sec__name(const GElf_Shdr *shdr, const Elf_Data *secstrs) { return secstrs->d_buf + shdr->sh_name; } static inline int elf_sec__is_text(const GElf_Shdr *shdr, const Elf_Data *secstrs) { return strstr(elf_sec__name(shdr, secstrs), "text") != NULL; } static inline bool elf_sec__is_data(const GElf_Shdr *shdr, const Elf_Data *secstrs) { return strstr(elf_sec__name(shdr, secstrs), "data") != NULL; } static inline const char *elf_sym__name(const GElf_Sym *sym, const Elf_Data *symstrs) { return symstrs->d_buf + sym->st_name; } static Elf_Scn *elf_section_by_name(Elf *elf, GElf_Ehdr *ep, GElf_Shdr *shp, const char *name, size_t *idx) { Elf_Scn *sec = NULL; size_t cnt = 1; while ((sec = elf_nextscn(elf, sec)) != NULL) { char *str; gelf_getshdr(sec, shp); str = elf_strptr(elf, ep->e_shstrndx, shp->sh_name); if (!strcmp(name, str)) { if (idx) *idx = cnt; break; } ++cnt; } return sec; } #define elf_section__for_each_rel(reldata, pos, pos_mem, idx, nr_entries) \ for (idx = 0, pos = gelf_getrel(reldata, 0, &pos_mem); \ idx < nr_entries; \ ++idx, pos = gelf_getrel(reldata, idx, &pos_mem)) #define elf_section__for_each_rela(reldata, pos, pos_mem, idx, nr_entries) \ for (idx = 0, pos = gelf_getrela(reldata, 0, &pos_mem); \ idx < nr_entries; \ ++idx, pos = gelf_getrela(reldata, idx, &pos_mem)) /* * We need to check if we have a .dynsym, so that we can handle the * .plt, synthesizing its symbols, that aren't on the symtabs (be it * .dynsym or .symtab). * And always look at the original dso, not at debuginfo packages, that * have the PLT data stripped out (shdr_rel_plt.sh_type == SHT_NOBITS). */ static int dso__synthesize_plt_symbols(struct dso *dso, char *name, struct map *map, symbol_filter_t filter) { uint32_t nr_rel_entries, idx; GElf_Sym sym; u64 plt_offset; GElf_Shdr shdr_plt; struct symbol *f; GElf_Shdr shdr_rel_plt, shdr_dynsym; Elf_Data *reldata, *syms, *symstrs; Elf_Scn *scn_plt_rel, *scn_symstrs, *scn_dynsym; size_t dynsym_idx; GElf_Ehdr ehdr; char sympltname[1024]; Elf *elf; int nr = 0, symidx, fd, err = 0; fd = open(name, O_RDONLY); if (fd < 0) goto out; elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL); if (elf == NULL) goto out_close; if (gelf_getehdr(elf, &ehdr) == NULL) goto out_elf_end; scn_dynsym = elf_section_by_name(elf, &ehdr, &shdr_dynsym, ".dynsym", &dynsym_idx); if (scn_dynsym == NULL) goto out_elf_end; scn_plt_rel = elf_section_by_name(elf, &ehdr, &shdr_rel_plt, ".rela.plt", NULL); if (scn_plt_rel == NULL) { scn_plt_rel = elf_section_by_name(elf, &ehdr, &shdr_rel_plt, ".rel.plt", NULL); if (scn_plt_rel == NULL) goto out_elf_end; } err = -1; if (shdr_rel_plt.sh_link != dynsym_idx) goto out_elf_end; if (elf_section_by_name(elf, &ehdr, &shdr_plt, ".plt", NULL) == NULL) goto out_elf_end; /* * Fetch the relocation section to find the idxes to the GOT * and the symbols in the .dynsym they refer to. */ reldata = elf_getdata(scn_plt_rel, NULL); if (reldata == NULL) goto out_elf_end; syms = elf_getdata(scn_dynsym, NULL); if (syms == NULL) goto out_elf_end; scn_symstrs = elf_getscn(elf, shdr_dynsym.sh_link); if (scn_symstrs == NULL) goto out_elf_end; symstrs = elf_getdata(scn_symstrs, NULL); if (symstrs == NULL) goto out_elf_end; nr_rel_entries = shdr_rel_plt.sh_size / shdr_rel_plt.sh_entsize; plt_offset = shdr_plt.sh_offset; if (shdr_rel_plt.sh_type == SHT_RELA) { GElf_Rela pos_mem, *pos; elf_section__for_each_rela(reldata, pos, pos_mem, idx, nr_rel_entries) { symidx = GELF_R_SYM(pos->r_info); plt_offset += shdr_plt.sh_entsize; gelf_getsym(syms, symidx, &sym); snprintf(sympltname, sizeof(sympltname), "%s@plt", elf_sym__name(&sym, symstrs)); f = symbol__new(plt_offset, shdr_plt.sh_entsize, STB_GLOBAL, sympltname); if (!f) goto out_elf_end; if (filter && filter(map, f)) symbol__delete(f); else { symbols__insert(&dso->symbols[map->type], f); ++nr; } } } else if (shdr_rel_plt.sh_type == SHT_REL) { GElf_Rel pos_mem, *pos; elf_section__for_each_rel(reldata, pos, pos_mem, idx, nr_rel_entries) { symidx = GELF_R_SYM(pos->r_info); plt_offset += shdr_plt.sh_entsize; gelf_getsym(syms, symidx, &sym); snprintf(sympltname, sizeof(sympltname), "%s@plt", elf_sym__name(&sym, symstrs)); f = symbol__new(plt_offset, shdr_plt.sh_entsize, STB_GLOBAL, sympltname); if (!f) goto out_elf_end; if (filter && filter(map, f)) symbol__delete(f); else { symbols__insert(&dso->symbols[map->type], f); ++nr; } } } err = 0; out_elf_end: elf_end(elf); out_close: close(fd); if (err == 0) return nr; out: pr_debug("%s: problems reading %s PLT info.\n", __func__, dso->long_name); return 0; } static bool elf_sym__is_a(GElf_Sym *sym, enum map_type type) { switch (type) { case MAP__FUNCTION: return elf_sym__is_function(sym); case MAP__VARIABLE: return elf_sym__is_object(sym); default: return false; } } static bool elf_sec__is_a(GElf_Shdr *shdr, Elf_Data *secstrs, enum map_type type) { switch (type) { case MAP__FUNCTION: return elf_sec__is_text(shdr, secstrs); case MAP__VARIABLE: return elf_sec__is_data(shdr, secstrs); default: return false; } } static size_t elf_addr_to_index(Elf *elf, GElf_Addr addr) { Elf_Scn *sec = NULL; GElf_Shdr shdr; size_t cnt = 1; while ((sec = elf_nextscn(elf, sec)) != NULL) { gelf_getshdr(sec, &shdr); if ((addr >= shdr.sh_addr) && (addr < (shdr.sh_addr + shdr.sh_size))) return cnt; ++cnt; } return -1; } static int dso__load_sym(struct dso *dso, struct map *map, const char *name, int fd, symbol_filter_t filter, int kmodule, int want_symtab) { struct kmap *kmap = dso->kernel ? map__kmap(map) : NULL; struct map *curr_map = map; struct dso *curr_dso = dso; Elf_Data *symstrs, *secstrs; uint32_t nr_syms; int err = -1; uint32_t idx; GElf_Ehdr ehdr; GElf_Shdr shdr, opdshdr; Elf_Data *syms, *opddata = NULL; GElf_Sym sym; Elf_Scn *sec, *sec_strndx, *opdsec; Elf *elf; int nr = 0; size_t opdidx = 0; elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL); if (elf == NULL) { pr_debug("%s: cannot read %s ELF file.\n", __func__, name); goto out_close; } if (gelf_getehdr(elf, &ehdr) == NULL) { pr_debug("%s: cannot get elf header.\n", __func__); goto out_elf_end; } /* Always reject images with a mismatched build-id: */ if (dso->has_build_id) { u8 build_id[BUILD_ID_SIZE]; if (elf_read_build_id(elf, build_id, BUILD_ID_SIZE) < 0) goto out_elf_end; if (!dso__build_id_equal(dso, build_id)) goto out_elf_end; } sec = elf_section_by_name(elf, &ehdr, &shdr, ".symtab", NULL); if (sec == NULL) { if (want_symtab) goto out_elf_end; sec = elf_section_by_name(elf, &ehdr, &shdr, ".dynsym", NULL); if (sec == NULL) goto out_elf_end; } opdsec = elf_section_by_name(elf, &ehdr, &opdshdr, ".opd", &opdidx); if (opdshdr.sh_type != SHT_PROGBITS) opdsec = NULL; if (opdsec) opddata = elf_rawdata(opdsec, NULL); syms = elf_getdata(sec, NULL); if (syms == NULL) goto out_elf_end; sec = elf_getscn(elf, shdr.sh_link); if (sec == NULL) goto out_elf_end; symstrs = elf_getdata(sec, NULL); if (symstrs == NULL) goto out_elf_end; sec_strndx = elf_getscn(elf, ehdr.e_shstrndx); if (sec_strndx == NULL) goto out_elf_end; secstrs = elf_getdata(sec_strndx, NULL); if (secstrs == NULL) goto out_elf_end; nr_syms = shdr.sh_size / shdr.sh_entsize; memset(&sym, 0, sizeof(sym)); if (dso->kernel == DSO_TYPE_USER) { dso->adjust_symbols = (ehdr.e_type == ET_EXEC || elf_section_by_name(elf, &ehdr, &shdr, ".gnu.prelink_undo", NULL) != NULL); } else { dso->adjust_symbols = 0; } elf_symtab__for_each_symbol(syms, nr_syms, idx, sym) { struct symbol *f; const char *elf_name = elf_sym__name(&sym, symstrs); char *demangled = NULL; int is_label = elf_sym__is_label(&sym); const char *section_name; if (kmap && kmap->ref_reloc_sym && kmap->ref_reloc_sym->name && strcmp(elf_name, kmap->ref_reloc_sym->name) == 0) kmap->ref_reloc_sym->unrelocated_addr = sym.st_value; if (!is_label && !elf_sym__is_a(&sym, map->type)) continue; /* Reject ARM ELF "mapping symbols": these aren't unique and * don't identify functions, so will confuse the profile * output: */ if (ehdr.e_machine == EM_ARM) { if (!strcmp(elf_name, "$a") || !strcmp(elf_name, "$d") || !strcmp(elf_name, "$t")) continue; } if (opdsec && sym.st_shndx == opdidx) { u32 offset = sym.st_value - opdshdr.sh_addr; u64 *opd = opddata->d_buf + offset; sym.st_value = *opd; sym.st_shndx = elf_addr_to_index(elf, sym.st_value); } sec = elf_getscn(elf, sym.st_shndx); if (!sec) goto out_elf_end; gelf_getshdr(sec, &shdr); if (is_label && !elf_sec__is_a(&shdr, secstrs, map->type)) continue; section_name = elf_sec__name(&shdr, secstrs); /* On ARM, symbols for thumb functions have 1 added to * the symbol address as a flag - remove it */ if ((ehdr.e_machine == EM_ARM) && (map->type == MAP__FUNCTION) && (sym.st_value & 1)) --sym.st_value; if (dso->kernel != DSO_TYPE_USER || kmodule) { char dso_name[PATH_MAX]; if (strcmp(section_name, (curr_dso->short_name + dso->short_name_len)) == 0) goto new_symbol; if (strcmp(section_name, ".text") == 0) { curr_map = map; curr_dso = dso; goto new_symbol; } snprintf(dso_name, sizeof(dso_name), "%s%s", dso->short_name, section_name); curr_map = map_groups__find_by_name(kmap->kmaps, map->type, dso_name); if (curr_map == NULL) { u64 start = sym.st_value; if (kmodule) start += map->start + shdr.sh_offset; curr_dso = dso__new(dso_name); if (curr_dso == NULL) goto out_elf_end; curr_dso->kernel = dso->kernel; curr_dso->long_name = dso->long_name; curr_dso->long_name_len = dso->long_name_len; curr_map = map__new2(start, curr_dso, map->type); if (curr_map == NULL) { dso__delete(curr_dso); goto out_elf_end; } curr_map->map_ip = identity__map_ip; curr_map->unmap_ip = identity__map_ip; curr_dso->symtab_type = dso->symtab_type; map_groups__insert(kmap->kmaps, curr_map); dsos__add(&dso->node, curr_dso); dso__set_loaded(curr_dso, map->type); } else curr_dso = curr_map->dso; goto new_symbol; } if (curr_dso->adjust_symbols) { pr_debug4("%s: adjusting symbol: st_value: %#" PRIx64 " " "sh_addr: %#" PRIx64 " sh_offset: %#" PRIx64 "\n", __func__, (u64)sym.st_value, (u64)shdr.sh_addr, (u64)shdr.sh_offset); sym.st_value -= shdr.sh_addr - shdr.sh_offset; } /* * We need to figure out if the object was created from C++ sources * DWARF DW_compile_unit has this, but we don't always have access * to it... */ demangled = bfd_demangle(NULL, elf_name, DMGL_PARAMS | DMGL_ANSI); if (demangled != NULL) elf_name = demangled; new_symbol: f = symbol__new(sym.st_value, sym.st_size, GELF_ST_BIND(sym.st_info), elf_name); free(demangled); if (!f) goto out_elf_end; if (filter && filter(curr_map, f)) symbol__delete(f); else { symbols__insert(&curr_dso->symbols[curr_map->type], f); nr++; } } /* * For misannotated, zeroed, ASM function sizes. */ if (nr > 0) { symbols__fixup_duplicate(&dso->symbols[map->type]); symbols__fixup_end(&dso->symbols[map->type]); if (kmap) { /* * We need to fixup this here too because we create new * maps here, for things like vsyscall sections. */ __map_groups__fixup_end(kmap->kmaps, map->type); } } err = nr; out_elf_end: elf_end(elf); out_close: return err; } static bool dso__build_id_equal(const struct dso *dso, u8 *build_id) { return memcmp(dso->build_id, build_id, sizeof(dso->build_id)) == 0; } bool __dsos__read_build_ids(struct list_head *head, bool with_hits) { bool have_build_id = false; struct dso *pos; list_for_each_entry(pos, head, node) { if (with_hits && !pos->hit) continue; if (pos->has_build_id) { have_build_id = true; continue; } if (filename__read_build_id(pos->long_name, pos->build_id, sizeof(pos->build_id)) > 0) { have_build_id = true; pos->has_build_id = true; } } return have_build_id; } /* * Align offset to 4 bytes as needed for note name and descriptor data. */ #define NOTE_ALIGN(n) (((n) + 3) & -4U) static int elf_read_build_id(Elf *elf, void *bf, size_t size) { int err = -1; GElf_Ehdr ehdr; GElf_Shdr shdr; Elf_Data *data; Elf_Scn *sec; Elf_Kind ek; void *ptr; if (size < BUILD_ID_SIZE) goto out; ek = elf_kind(elf); if (ek != ELF_K_ELF) goto out; if (gelf_getehdr(elf, &ehdr) == NULL) { pr_err("%s: cannot get elf header.\n", __func__); goto out; } sec = elf_section_by_name(elf, &ehdr, &shdr, ".note.gnu.build-id", NULL); if (sec == NULL) { sec = elf_section_by_name(elf, &ehdr, &shdr, ".notes", NULL); if (sec == NULL) goto out; } data = elf_getdata(sec, NULL); if (data == NULL) goto out; ptr = data->d_buf; while (ptr < (data->d_buf + data->d_size)) { GElf_Nhdr *nhdr = ptr; size_t namesz = NOTE_ALIGN(nhdr->n_namesz), descsz = NOTE_ALIGN(nhdr->n_descsz); const char *name; ptr += sizeof(*nhdr); name = ptr; ptr += namesz; if (nhdr->n_type == NT_GNU_BUILD_ID && nhdr->n_namesz == sizeof("GNU")) { if (memcmp(name, "GNU", sizeof("GNU")) == 0) { size_t sz = min(size, descsz); memcpy(bf, ptr, sz); memset(bf + sz, 0, size - sz); err = descsz; break; } } ptr += descsz; } out: return err; } int filename__read_build_id(const char *filename, void *bf, size_t size) { int fd, err = -1; Elf *elf; if (size < BUILD_ID_SIZE) goto out; fd = open(filename, O_RDONLY); if (fd < 0) goto out; elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL); if (elf == NULL) { pr_debug2("%s: cannot read %s ELF file.\n", __func__, filename); goto out_close; } err = elf_read_build_id(elf, bf, size); elf_end(elf); out_close: close(fd); out: return err; } int sysfs__read_build_id(const char *filename, void *build_id, size_t size) { int fd, err = -1; if (size < BUILD_ID_SIZE) goto out; fd = open(filename, O_RDONLY); if (fd < 0) goto out; while (1) { char bf[BUFSIZ]; GElf_Nhdr nhdr; size_t namesz, descsz; if (read(fd, &nhdr, sizeof(nhdr)) != sizeof(nhdr)) break; namesz = NOTE_ALIGN(nhdr.n_namesz); descsz = NOTE_ALIGN(nhdr.n_descsz); if (nhdr.n_type == NT_GNU_BUILD_ID && nhdr.n_namesz == sizeof("GNU")) { if (read(fd, bf, namesz) != (ssize_t)namesz) break; if (memcmp(bf, "GNU", sizeof("GNU")) == 0) { size_t sz = min(descsz, size); if (read(fd, build_id, sz) == (ssize_t)sz) { memset(build_id + sz, 0, size - sz); err = 0; break; } } else if (read(fd, bf, descsz) != (ssize_t)descsz) break; } else { int n = namesz + descsz; if (read(fd, bf, n) != n) break; } } close(fd); out: return err; } char dso__symtab_origin(const struct dso *dso) { static const char origin[] = { [SYMTAB__KALLSYMS] = 'k', [SYMTAB__JAVA_JIT] = 'j', [SYMTAB__BUILD_ID_CACHE] = 'B', [SYMTAB__FEDORA_DEBUGINFO] = 'f', [SYMTAB__UBUNTU_DEBUGINFO] = 'u', [SYMTAB__BUILDID_DEBUGINFO] = 'b', [SYMTAB__SYSTEM_PATH_DSO] = 'd', [SYMTAB__SYSTEM_PATH_KMODULE] = 'K', [SYMTAB__GUEST_KALLSYMS] = 'g', [SYMTAB__GUEST_KMODULE] = 'G', }; if (dso == NULL || dso->symtab_type == SYMTAB__NOT_FOUND) return '!'; return origin[dso->symtab_type]; } int dso__load(struct dso *dso, struct map *map, symbol_filter_t filter) { int size = PATH_MAX; char *name; int ret = -1; int fd; struct machine *machine; const char *root_dir; int want_symtab; dso__set_loaded(dso, map->type); if (dso->kernel == DSO_TYPE_KERNEL) return dso__load_kernel_sym(dso, map, filter); else if (dso->kernel == DSO_TYPE_GUEST_KERNEL) return dso__load_guest_kernel_sym(dso, map, filter); if (map->groups && map->groups->machine) machine = map->groups->machine; else machine = NULL; name = malloc(size); if (!name) return -1; dso->adjust_symbols = 0; if (strncmp(dso->name, "/tmp/perf-", 10) == 0) { struct stat st; if (lstat(dso->name, &st) < 0) return -1; if (st.st_uid && (st.st_uid != geteuid())) { pr_warning("File %s not owned by current user or root, " "ignoring it.\n", dso->name); return -1; } ret = dso__load_perf_map(dso, map, filter); dso->symtab_type = ret > 0 ? SYMTAB__JAVA_JIT : SYMTAB__NOT_FOUND; return ret; } /* Iterate over candidate debug images. * On the first pass, only load images if they have a full symtab. * Failing that, do a second pass where we accept .dynsym also */ want_symtab = 1; restart: for (dso->symtab_type = SYMTAB__BUILD_ID_CACHE; dso->symtab_type != SYMTAB__NOT_FOUND; dso->symtab_type++) { switch (dso->symtab_type) { case SYMTAB__BUILD_ID_CACHE: /* skip the locally configured cache if a symfs is given */ if (symbol_conf.symfs[0] || (dso__build_id_filename(dso, name, size) == NULL)) { continue; } break; case SYMTAB__FEDORA_DEBUGINFO: snprintf(name, size, "%s/usr/lib/debug%s.debug", symbol_conf.symfs, dso->long_name); break; case SYMTAB__UBUNTU_DEBUGINFO: snprintf(name, size, "%s/usr/lib/debug%s", symbol_conf.symfs, dso->long_name); break; case SYMTAB__BUILDID_DEBUGINFO: { char build_id_hex[BUILD_ID_SIZE * 2 + 1]; if (!dso->has_build_id) continue; build_id__sprintf(dso->build_id, sizeof(dso->build_id), build_id_hex); snprintf(name, size, "%s/usr/lib/debug/.build-id/%.2s/%s.debug", symbol_conf.symfs, build_id_hex, build_id_hex + 2); } break; case SYMTAB__SYSTEM_PATH_DSO: snprintf(name, size, "%s%s", symbol_conf.symfs, dso->long_name); break; case SYMTAB__GUEST_KMODULE: if (map->groups && machine) root_dir = machine->root_dir; else root_dir = ""; snprintf(name, size, "%s%s%s", symbol_conf.symfs, root_dir, dso->long_name); break; case SYMTAB__SYSTEM_PATH_KMODULE: snprintf(name, size, "%s%s", symbol_conf.symfs, dso->long_name); break; default:; } /* Name is now the name of the next image to try */ fd = open(name, O_RDONLY); if (fd < 0) continue; ret = dso__load_sym(dso, map, name, fd, filter, 0, want_symtab); close(fd); /* * Some people seem to have debuginfo files _WITHOUT_ debug * info!?!? */ if (!ret) continue; if (ret > 0) { int nr_plt; nr_plt = dso__synthesize_plt_symbols(dso, name, map, filter); if (nr_plt > 0) ret += nr_plt; break; } } /* * If we wanted a full symtab but no image had one, * relax our requirements and repeat the search. */ if (ret <= 0 && want_symtab) { want_symtab = 0; goto restart; } free(name); if (ret < 0 && strstr(dso->name, " (deleted)") != NULL) return 0; return ret; } struct map *map_groups__find_by_name(struct map_groups *mg, enum map_type type, const char *name) { struct rb_node *nd; for (nd = rb_first(&mg->maps[type]); nd; nd = rb_next(nd)) { struct map *map = rb_entry(nd, struct map, rb_node); if (map->dso && strcmp(map->dso->short_name, name) == 0) return map; } return NULL; } static int dso__kernel_module_get_build_id(struct dso *dso, const char *root_dir) { char filename[PATH_MAX]; /* * kernel module short names are of the form "[module]" and * we need just "module" here. */ const char *name = dso->short_name + 1; snprintf(filename, sizeof(filename), "%s/sys/module/%.*s/notes/.note.gnu.build-id", root_dir, (int)strlen(name) - 1, name); if (sysfs__read_build_id(filename, dso->build_id, sizeof(dso->build_id)) == 0) dso->has_build_id = true; return 0; } static int map_groups__set_modules_path_dir(struct map_groups *mg, const char *dir_name) { struct dirent *dent; DIR *dir = opendir(dir_name); int ret = 0; if (!dir) { pr_debug("%s: cannot open %s dir\n", __func__, dir_name); return -1; } while ((dent = readdir(dir)) != NULL) { char path[PATH_MAX]; struct stat st; /*sshfs might return bad dent->d_type, so we have to stat*/ snprintf(path, sizeof(path), "%s/%s", dir_name, dent->d_name); if (stat(path, &st)) continue; if (S_ISDIR(st.st_mode)) { if (!strcmp(dent->d_name, ".") || !strcmp(dent->d_name, "..")) continue; ret = map_groups__set_modules_path_dir(mg, path); if (ret < 0) goto out; } else { char *dot = strrchr(dent->d_name, '.'), dso_name[PATH_MAX]; struct map *map; char *long_name; if (dot == NULL || strcmp(dot, ".ko")) continue; snprintf(dso_name, sizeof(dso_name), "[%.*s]", (int)(dot - dent->d_name), dent->d_name); strxfrchar(dso_name, '-', '_'); map = map_groups__find_by_name(mg, MAP__FUNCTION, dso_name); if (map == NULL) continue; long_name = strdup(path); if (long_name == NULL) { ret = -1; goto out; } dso__set_long_name(map->dso, long_name); map->dso->lname_alloc = 1; dso__kernel_module_get_build_id(map->dso, ""); } } out: closedir(dir); return ret; } static char *get_kernel_version(const char *root_dir) { char version[PATH_MAX]; FILE *file; char *name, *tmp; const char *prefix = "Linux version "; sprintf(version, "%s/proc/version", root_dir); file = fopen(version, "r"); if (!file) return NULL; version[0] = '\0'; tmp = fgets(version, sizeof(version), file); fclose(file); name = strstr(version, prefix); if (!name) return NULL; name += strlen(prefix); tmp = strchr(name, ' '); if (tmp) *tmp = '\0'; return strdup(name); } static int machine__set_modules_path(struct machine *machine) { char *version; char modules_path[PATH_MAX]; version = get_kernel_version(machine->root_dir); if (!version) return -1; snprintf(modules_path, sizeof(modules_path), "%s/lib/modules/%s/kernel", machine->root_dir, version); free(version); return map_groups__set_modules_path_dir(&machine->kmaps, modules_path); } /* * Constructor variant for modules (where we know from /proc/modules where * they are loaded) and for vmlinux, where only after we load all the * symbols we'll know where it starts and ends. */ static struct map *map__new2(u64 start, struct dso *dso, enum map_type type) { struct map *map = calloc(1, (sizeof(*map) + (dso->kernel ? sizeof(struct kmap) : 0))); if (map != NULL) { /* * ->end will be filled after we load all the symbols */ map__init(map, type, start, 0, 0, dso); } return map; } struct map *machine__new_module(struct machine *machine, u64 start, const char *filename) { struct map *map; struct dso *dso = __dsos__findnew(&machine->kernel_dsos, filename); if (dso == NULL) return NULL; map = map__new2(start, dso, MAP__FUNCTION); if (map == NULL) return NULL; if (machine__is_host(machine)) dso->symtab_type = SYMTAB__SYSTEM_PATH_KMODULE; else dso->symtab_type = SYMTAB__GUEST_KMODULE; map_groups__insert(&machine->kmaps, map); return map; } static int machine__create_modules(struct machine *machine) { char *line = NULL; size_t n; FILE *file; struct map *map; const char *modules; char path[PATH_MAX]; if (machine__is_default_guest(machine)) modules = symbol_conf.default_guest_modules; else { sprintf(path, "%s/proc/modules", machine->root_dir); modules = path; } if (symbol__restricted_filename(path, "/proc/modules")) return -1; file = fopen(modules, "r"); if (file == NULL) return -1; while (!feof(file)) { char name[PATH_MAX]; u64 start; char *sep; int line_len; line_len = getline(&line, &n, file); if (line_len < 0) break; if (!line) goto out_failure; line[--line_len] = '\0'; /* \n */ sep = strrchr(line, 'x'); if (sep == NULL) continue; hex2u64(sep + 1, &start); sep = strchr(line, ' '); if (sep == NULL) continue; *sep = '\0'; snprintf(name, sizeof(name), "[%s]", line); map = machine__new_module(machine, start, name); if (map == NULL) goto out_delete_line; dso__kernel_module_get_build_id(map->dso, machine->root_dir); } free(line); fclose(file); return machine__set_modules_path(machine); out_delete_line: free(line); out_failure: return -1; } int dso__load_vmlinux(struct dso *dso, struct map *map, const char *vmlinux, symbol_filter_t filter) { int err = -1, fd; char symfs_vmlinux[PATH_MAX]; snprintf(symfs_vmlinux, sizeof(symfs_vmlinux), "%s%s", symbol_conf.symfs, vmlinux); fd = open(symfs_vmlinux, O_RDONLY); if (fd < 0) return -1; dso__set_long_name(dso, (char *)vmlinux); dso__set_loaded(dso, map->type); err = dso__load_sym(dso, map, symfs_vmlinux, fd, filter, 0, 0); close(fd); if (err > 0) pr_debug("Using %s for symbols\n", symfs_vmlinux); return err; } int dso__load_vmlinux_path(struct dso *dso, struct map *map, symbol_filter_t filter) { int i, err = 0; char *filename; pr_debug("Looking at the vmlinux_path (%d entries long)\n", vmlinux_path__nr_entries + 1); filename = dso__build_id_filename(dso, NULL, 0); if (filename != NULL) { err = dso__load_vmlinux(dso, map, filename, filter); if (err > 0) { dso__set_long_name(dso, filename); goto out; } free(filename); } for (i = 0; i < vmlinux_path__nr_entries; ++i) { err = dso__load_vmlinux(dso, map, vmlinux_path[i], filter); if (err > 0) { dso__set_long_name(dso, strdup(vmlinux_path[i])); break; } } out: return err; } static int dso__load_kernel_sym(struct dso *dso, struct map *map, symbol_filter_t filter) { int err; const char *kallsyms_filename = NULL; char *kallsyms_allocated_filename = NULL; /* * Step 1: if the user specified a kallsyms or vmlinux filename, use * it and only it, reporting errors to the user if it cannot be used. * * For instance, try to analyse an ARM perf.data file _without_ a * build-id, or if the user specifies the wrong path to the right * vmlinux file, obviously we can't fallback to another vmlinux (a * x86_86 one, on the machine where analysis is being performed, say), * or worse, /proc/kallsyms. * * If the specified file _has_ a build-id and there is a build-id * section in the perf.data file, we will still do the expected * validation in dso__load_vmlinux and will bail out if they don't * match. */ if (symbol_conf.kallsyms_name != NULL) { kallsyms_filename = symbol_conf.kallsyms_name; goto do_kallsyms; } if (symbol_conf.vmlinux_name != NULL) { err = dso__load_vmlinux(dso, map, symbol_conf.vmlinux_name, filter); if (err > 0) { dso__set_long_name(dso, strdup(symbol_conf.vmlinux_name)); goto out_fixup; } return err; } if (vmlinux_path != NULL) { err = dso__load_vmlinux_path(dso, map, filter); if (err > 0) goto out_fixup; } /* do not try local files if a symfs was given */ if (symbol_conf.symfs[0] != 0) return -1; /* * Say the kernel DSO was created when processing the build-id header table, * we have a build-id, so check if it is the same as the running kernel, * using it if it is. */ if (dso->has_build_id) { u8 kallsyms_build_id[BUILD_ID_SIZE]; char sbuild_id[BUILD_ID_SIZE * 2 + 1]; if (sysfs__read_build_id("/sys/kernel/notes", kallsyms_build_id, sizeof(kallsyms_build_id)) == 0) { if (dso__build_id_equal(dso, kallsyms_build_id)) { kallsyms_filename = "/proc/kallsyms"; goto do_kallsyms; } } /* * Now look if we have it on the build-id cache in * $HOME/.debug/[kernel.kallsyms]. */ build_id__sprintf(dso->build_id, sizeof(dso->build_id), sbuild_id); if (asprintf(&kallsyms_allocated_filename, "%s/.debug/[kernel.kallsyms]/%s", getenv("HOME"), sbuild_id) == -1) { pr_err("Not enough memory for kallsyms file lookup\n"); return -1; } kallsyms_filename = kallsyms_allocated_filename; if (access(kallsyms_filename, F_OK)) { pr_err("No kallsyms or vmlinux with build-id %s " "was found\n", sbuild_id); free(kallsyms_allocated_filename); return -1; } } else { /* * Last resort, if we don't have a build-id and couldn't find * any vmlinux file, try the running kernel kallsyms table. */ kallsyms_filename = "/proc/kallsyms"; } do_kallsyms: err = dso__load_kallsyms(dso, kallsyms_filename, map, filter); if (err > 0) pr_debug("Using %s for symbols\n", kallsyms_filename); free(kallsyms_allocated_filename); if (err > 0) { out_fixup: if (kallsyms_filename != NULL) dso__set_long_name(dso, strdup("[kernel.kallsyms]")); map__fixup_start(map); map__fixup_end(map); } return err; } static int dso__load_guest_kernel_sym(struct dso *dso, struct map *map, symbol_filter_t filter) { int err; const char *kallsyms_filename = NULL; struct machine *machine; char path[PATH_MAX]; if (!map->groups) { pr_debug("Guest kernel map hasn't the point to groups\n"); return -1; } machine = map->groups->machine; if (machine__is_default_guest(machine)) { /* * if the user specified a vmlinux filename, use it and only * it, reporting errors to the user if it cannot be used. * Or use file guest_kallsyms inputted by user on commandline */ if (symbol_conf.default_guest_vmlinux_name != NULL) { err = dso__load_vmlinux(dso, map, symbol_conf.default_guest_vmlinux_name, filter); goto out_try_fixup; } kallsyms_filename = symbol_conf.default_guest_kallsyms; if (!kallsyms_filename) return -1; } else { sprintf(path, "%s/proc/kallsyms", machine->root_dir); kallsyms_filename = path; } err = dso__load_kallsyms(dso, kallsyms_filename, map, filter); if (err > 0) pr_debug("Using %s for symbols\n", kallsyms_filename); out_try_fixup: if (err > 0) { if (kallsyms_filename != NULL) { machine__mmap_name(machine, path, sizeof(path)); dso__set_long_name(dso, strdup(path)); } map__fixup_start(map); map__fixup_end(map); } return err; } static void dsos__add(struct list_head *head, struct dso *dso) { list_add_tail(&dso->node, head); } static struct dso *dsos__find(struct list_head *head, const char *name) { struct dso *pos; list_for_each_entry(pos, head, node) if (strcmp(pos->long_name, name) == 0) return pos; return NULL; } struct dso *__dsos__findnew(struct list_head *head, const char *name) { struct dso *dso = dsos__find(head, name); if (!dso) { dso = dso__new(name); if (dso != NULL) { dsos__add(head, dso); dso__set_basename(dso); } } return dso; } size_t __dsos__fprintf(struct list_head *head, FILE *fp) { struct dso *pos; size_t ret = 0; list_for_each_entry(pos, head, node) { int i; for (i = 0; i < MAP__NR_TYPES; ++i) ret += dso__fprintf(pos, i, fp); } return ret; } size_t machines__fprintf_dsos(struct rb_root *machines, FILE *fp) { struct rb_node *nd; size_t ret = 0; for (nd = rb_first(machines); nd; nd = rb_next(nd)) { struct machine *pos = rb_entry(nd, struct machine, rb_node); ret += __dsos__fprintf(&pos->kernel_dsos, fp); ret += __dsos__fprintf(&pos->user_dsos, fp); } return ret; } static size_t __dsos__fprintf_buildid(struct list_head *head, FILE *fp, bool with_hits) { struct dso *pos; size_t ret = 0; list_for_each_entry(pos, head, node) { if (with_hits && !pos->hit) continue; ret += dso__fprintf_buildid(pos, fp); ret += fprintf(fp, " %s\n", pos->long_name); } return ret; } size_t machine__fprintf_dsos_buildid(struct machine *machine, FILE *fp, bool with_hits) { return __dsos__fprintf_buildid(&machine->kernel_dsos, fp, with_hits) + __dsos__fprintf_buildid(&machine->user_dsos, fp, with_hits); } size_t machines__fprintf_dsos_buildid(struct rb_root *machines, FILE *fp, bool with_hits) { struct rb_node *nd; size_t ret = 0; for (nd = rb_first(machines); nd; nd = rb_next(nd)) { struct machine *pos = rb_entry(nd, struct machine, rb_node); ret += machine__fprintf_dsos_buildid(pos, fp, with_hits); } return ret; } static struct dso* dso__kernel_findnew(struct machine *machine, const char *name, const char *short_name, int dso_type) { /* * The kernel dso could be created by build_id processing. */ struct dso *dso = __dsos__findnew(&machine->kernel_dsos, name); /* * We need to run this in all cases, since during the build_id * processing we had no idea this was the kernel dso. */ if (dso != NULL) { dso__set_short_name(dso, short_name); dso->kernel = dso_type; } return dso; } void dso__read_running_kernel_build_id(struct dso *dso, struct machine *machine) { char path[PATH_MAX]; if (machine__is_default_guest(machine)) return; sprintf(path, "%s/sys/kernel/notes", machine->root_dir); if (sysfs__read_build_id(path, dso->build_id, sizeof(dso->build_id)) == 0) dso->has_build_id = true; } static struct dso *machine__get_kernel(struct machine *machine) { const char *vmlinux_name = NULL; struct dso *kernel; if (machine__is_host(machine)) { vmlinux_name = symbol_conf.vmlinux_name; if (!vmlinux_name) vmlinux_name = "[kernel.kallsyms]"; kernel = dso__kernel_findnew(machine, vmlinux_name, "[kernel]", DSO_TYPE_KERNEL); } else { char bf[PATH_MAX]; if (machine__is_default_guest(machine)) vmlinux_name = symbol_conf.default_guest_vmlinux_name; if (!vmlinux_name) vmlinux_name = machine__mmap_name(machine, bf, sizeof(bf)); kernel = dso__kernel_findnew(machine, vmlinux_name, "[guest.kernel]", DSO_TYPE_GUEST_KERNEL); } if (kernel != NULL && (!kernel->has_build_id)) dso__read_running_kernel_build_id(kernel, machine); return kernel; } struct process_args { u64 start; }; static int symbol__in_kernel(void *arg, const char *name, char type __used, u64 start, u64 end __used) { struct process_args *args = arg; if (strchr(name, '[')) return 0; args->start = start; return 1; } /* Figure out the start address of kernel map from /proc/kallsyms */ static u64 machine__get_kernel_start_addr(struct machine *machine) { const char *filename; char path[PATH_MAX]; struct process_args args; if (machine__is_host(machine)) { filename = "/proc/kallsyms"; } else { if (machine__is_default_guest(machine)) filename = (char *)symbol_conf.default_guest_kallsyms; else { sprintf(path, "%s/proc/kallsyms", machine->root_dir); filename = path; } } if (symbol__restricted_filename(filename, "/proc/kallsyms")) return 0; if (kallsyms__parse(filename, &args, symbol__in_kernel) <= 0) return 0; return args.start; } int __machine__create_kernel_maps(struct machine *machine, struct dso *kernel) { enum map_type type; u64 start = machine__get_kernel_start_addr(machine); for (type = 0; type < MAP__NR_TYPES; ++type) { struct kmap *kmap; machine->vmlinux_maps[type] = map__new2(start, kernel, type); if (machine->vmlinux_maps[type] == NULL) return -1; machine->vmlinux_maps[type]->map_ip = machine->vmlinux_maps[type]->unmap_ip = identity__map_ip; kmap = map__kmap(machine->vmlinux_maps[type]); kmap->kmaps = &machine->kmaps; map_groups__insert(&machine->kmaps, machine->vmlinux_maps[type]); } return 0; } void machine__destroy_kernel_maps(struct machine *machine) { enum map_type type; for (type = 0; type < MAP__NR_TYPES; ++type) { struct kmap *kmap; if (machine->vmlinux_maps[type] == NULL) continue; kmap = map__kmap(machine->vmlinux_maps[type]); map_groups__remove(&machine->kmaps, machine->vmlinux_maps[type]); if (kmap->ref_reloc_sym) { /* * ref_reloc_sym is shared among all maps, so free just * on one of them. */ if (type == MAP__FUNCTION) { free((char *)kmap->ref_reloc_sym->name); kmap->ref_reloc_sym->name = NULL; free(kmap->ref_reloc_sym); } kmap->ref_reloc_sym = NULL; } map__delete(machine->vmlinux_maps[type]); machine->vmlinux_maps[type] = NULL; } } int machine__create_kernel_maps(struct machine *machine) { struct dso *kernel = machine__get_kernel(machine); if (kernel == NULL || __machine__create_kernel_maps(machine, kernel) < 0) return -1; if (symbol_conf.use_modules && machine__create_modules(machine) < 0) pr_debug("Problems creating module maps, continuing anyway...\n"); /* * Now that we have all the maps created, just set the ->end of them: */ map_groups__fixup_end(&machine->kmaps); return 0; } static void vmlinux_path__exit(void) { while (--vmlinux_path__nr_entries >= 0) { free(vmlinux_path[vmlinux_path__nr_entries]); vmlinux_path[vmlinux_path__nr_entries] = NULL; } free(vmlinux_path); vmlinux_path = NULL; } static int vmlinux_path__init(void) { struct utsname uts; char bf[PATH_MAX]; vmlinux_path = malloc(sizeof(char *) * 5); if (vmlinux_path == NULL) return -1; vmlinux_path[vmlinux_path__nr_entries] = strdup("vmlinux"); if (vmlinux_path[vmlinux_path__nr_entries] == NULL) goto out_fail; ++vmlinux_path__nr_entries; vmlinux_path[vmlinux_path__nr_entries] = strdup("/boot/vmlinux"); if (vmlinux_path[vmlinux_path__nr_entries] == NULL) goto out_fail; ++vmlinux_path__nr_entries; /* only try running kernel version if no symfs was given */ if (symbol_conf.symfs[0] != 0) return 0; if (uname(&uts) < 0) return -1; snprintf(bf, sizeof(bf), "/boot/vmlinux-%s", uts.release); vmlinux_path[vmlinux_path__nr_entries] = strdup(bf); if (vmlinux_path[vmlinux_path__nr_entries] == NULL) goto out_fail; ++vmlinux_path__nr_entries; snprintf(bf, sizeof(bf), "/lib/modules/%s/build/vmlinux", uts.release); vmlinux_path[vmlinux_path__nr_entries] = strdup(bf); if (vmlinux_path[vmlinux_path__nr_entries] == NULL) goto out_fail; ++vmlinux_path__nr_entries; snprintf(bf, sizeof(bf), "/usr/lib/debug/lib/modules/%s/vmlinux", uts.release); vmlinux_path[vmlinux_path__nr_entries] = strdup(bf); if (vmlinux_path[vmlinux_path__nr_entries] == NULL) goto out_fail; ++vmlinux_path__nr_entries; return 0; out_fail: vmlinux_path__exit(); return -1; } size_t machine__fprintf_vmlinux_path(struct machine *machine, FILE *fp) { int i; size_t printed = 0; struct dso *kdso = machine->vmlinux_maps[MAP__FUNCTION]->dso; if (kdso->has_build_id) { char filename[PATH_MAX]; if (dso__build_id_filename(kdso, filename, sizeof(filename))) printed += fprintf(fp, "[0] %s\n", filename); } for (i = 0; i < vmlinux_path__nr_entries; ++i) printed += fprintf(fp, "[%d] %s\n", i + kdso->has_build_id, vmlinux_path[i]); return printed; } static int setup_list(struct strlist **list, const char *list_str, const char *list_name) { if (list_str == NULL) return 0; *list = strlist__new(true, list_str); if (!*list) { pr_err("problems parsing %s list\n", list_name); return -1; } return 0; } static bool symbol__read_kptr_restrict(void) { bool value = false; if (geteuid() != 0) { FILE *fp = fopen("/proc/sys/kernel/kptr_restrict", "r"); if (fp != NULL) { char line[8]; if (fgets(line, sizeof(line), fp) != NULL) value = atoi(line) != 0; fclose(fp); } } return value; } int symbol__init(void) { const char *symfs; if (symbol_conf.initialized) return 0; symbol_conf.priv_size = ALIGN(symbol_conf.priv_size, sizeof(u64)); elf_version(EV_CURRENT); if (symbol_conf.sort_by_name) symbol_conf.priv_size += (sizeof(struct symbol_name_rb_node) - sizeof(struct symbol)); if (symbol_conf.try_vmlinux_path && vmlinux_path__init() < 0) return -1; if (symbol_conf.field_sep && *symbol_conf.field_sep == '.') { pr_err("'.' is the only non valid --field-separator argument\n"); return -1; } if (setup_list(&symbol_conf.dso_list, symbol_conf.dso_list_str, "dso") < 0) return -1; if (setup_list(&symbol_conf.comm_list, symbol_conf.comm_list_str, "comm") < 0) goto out_free_dso_list; if (setup_list(&symbol_conf.sym_list, symbol_conf.sym_list_str, "symbol") < 0) goto out_free_comm_list; /* * A path to symbols of "/" is identical to "" * reset here for simplicity. */ symfs = realpath(symbol_conf.symfs, NULL); if (symfs == NULL) symfs = symbol_conf.symfs; if (strcmp(symfs, "/") == 0) symbol_conf.symfs = ""; if (symfs != symbol_conf.symfs) free((void *)symfs); symbol_conf.kptr_restrict = symbol__read_kptr_restrict(); symbol_conf.initialized = true; return 0; out_free_comm_list: strlist__delete(symbol_conf.comm_list); out_free_dso_list: strlist__delete(symbol_conf.dso_list); return -1; } void symbol__exit(void) { if (!symbol_conf.initialized) return; strlist__delete(symbol_conf.sym_list); strlist__delete(symbol_conf.dso_list); strlist__delete(symbol_conf.comm_list); vmlinux_path__exit(); symbol_conf.sym_list = symbol_conf.dso_list = symbol_conf.comm_list = NULL; symbol_conf.initialized = false; } int machines__create_kernel_maps(struct rb_root *machines, pid_t pid) { struct machine *machine = machines__findnew(machines, pid); if (machine == NULL) return -1; return machine__create_kernel_maps(machine); } static int hex(char ch) { if ((ch >= '0') && (ch <= '9')) return ch - '0'; if ((ch >= 'a') && (ch <= 'f')) return ch - 'a' + 10; if ((ch >= 'A') && (ch <= 'F')) return ch - 'A' + 10; return -1; } /* * While we find nice hex chars, build a long_val. * Return number of chars processed. */ int hex2u64(const char *ptr, u64 *long_val) { const char *p = ptr; *long_val = 0; while (*p) { const int hex_val = hex(*p); if (hex_val < 0) break; *long_val = (*long_val << 4) | hex_val; p++; } return p - ptr; } char *strxfrchar(char *s, char from, char to) { char *p = s; while ((p = strchr(p, from)) != NULL) *p++ = to; return s; } int machines__create_guest_kernel_maps(struct rb_root *machines) { int ret = 0; struct dirent **namelist = NULL; int i, items = 0; char path[PATH_MAX]; pid_t pid; if (symbol_conf.default_guest_vmlinux_name || symbol_conf.default_guest_modules || symbol_conf.default_guest_kallsyms) { machines__create_kernel_maps(machines, DEFAULT_GUEST_KERNEL_ID); } if (symbol_conf.guestmount) { items = scandir(symbol_conf.guestmount, &namelist, NULL, NULL); if (items <= 0) return -ENOENT; for (i = 0; i < items; i++) { if (!isdigit(namelist[i]->d_name[0])) { /* Filter out . and .. */ continue; } pid = atoi(namelist[i]->d_name); sprintf(path, "%s/%s/proc/kallsyms", symbol_conf.guestmount, namelist[i]->d_name); ret = access(path, R_OK); if (ret) { pr_debug("Can't access file %s\n", path); goto failure; } machines__create_kernel_maps(machines, pid); } failure: free(namelist); } return ret; } void machines__destroy_guest_kernel_maps(struct rb_root *machines) { struct rb_node *next = rb_first(machines); while (next) { struct machine *pos = rb_entry(next, struct machine, rb_node); next = rb_next(&pos->rb_node); rb_erase(&pos->rb_node, machines); machine__delete(pos); } } int machine__load_kallsyms(struct machine *machine, const char *filename, enum map_type type, symbol_filter_t filter) { struct map *map = machine->vmlinux_maps[type]; int ret = dso__load_kallsyms(map->dso, filename, map, filter); if (ret > 0) { dso__set_loaded(map->dso, type); /* * Since /proc/kallsyms will have multiple sessions for the * kernel, with modules between them, fixup the end of all * sections. */ __map_groups__fixup_end(&machine->kmaps, type); } return ret; } int machine__load_vmlinux_path(struct machine *machine, enum map_type type, symbol_filter_t filter) { struct map *map = machine->vmlinux_maps[type]; int ret = dso__load_vmlinux_path(map->dso, map, filter); if (ret > 0) { dso__set_loaded(map->dso, type); map__reloc_vmlinux(map); } return ret; }