11 #include <symbol/kallsyms.h>
14 #ifdef HAVE_CPLUS_DEMANGLE_SUPPORT
15 extern char *cplus_demangle(const char *, int);
17 static inline char *bfd_demangle(void __maybe_unused *v, const char *c, int i)
19 return cplus_demangle(c, i);
23 static inline char *bfd_demangle(void __maybe_unused *v,
24 const char __maybe_unused *c,
30 #define PACKAGE 'perf'
35 #ifndef HAVE_ELF_GETPHDRNUM_SUPPORT
36 static int elf_getphdrnum(Elf *elf, size_t *dst)
41 ehdr = gelf_getehdr(elf, &gehdr);
51 #ifndef NT_GNU_BUILD_ID
52 #define NT_GNU_BUILD_ID 3
56 * elf_symtab__for_each_symbol - iterate thru all the symbols
58 * @syms: struct elf_symtab instance to iterate
60 * @sym: GElf_Sym iterator
62 #define elf_symtab__for_each_symbol(syms, nr_syms, idx, sym) \
63 for (idx = 0, gelf_getsym(syms, idx, &sym);\
65 idx++, gelf_getsym(syms, idx, &sym))
67 static inline uint8_t elf_sym__type(const GElf_Sym *sym)
69 return GELF_ST_TYPE(sym->st_info);
72 static inline int elf_sym__is_function(const GElf_Sym *sym)
74 return (elf_sym__type(sym) == STT_FUNC ||
75 elf_sym__type(sym) == STT_GNU_IFUNC) &&
77 sym->st_shndx != SHN_UNDEF;
80 static inline bool elf_sym__is_object(const GElf_Sym *sym)
82 return elf_sym__type(sym) == STT_OBJECT &&
84 sym->st_shndx != SHN_UNDEF;
87 static inline int elf_sym__is_label(const GElf_Sym *sym)
89 return elf_sym__type(sym) == STT_NOTYPE &&
91 sym->st_shndx != SHN_UNDEF &&
92 sym->st_shndx != SHN_ABS;
95 static bool elf_sym__is_a(GElf_Sym *sym, enum map_type type)
99 return elf_sym__is_function(sym);
101 return elf_sym__is_object(sym);
107 static inline const char *elf_sym__name(const GElf_Sym *sym,
108 const Elf_Data *symstrs)
110 return symstrs->d_buf + sym->st_name;
113 static inline const char *elf_sec__name(const GElf_Shdr *shdr,
114 const Elf_Data *secstrs)
116 return secstrs->d_buf + shdr->sh_name;
119 static inline int elf_sec__is_text(const GElf_Shdr *shdr,
120 const Elf_Data *secstrs)
122 return strstr(elf_sec__name(shdr, secstrs), "text") != NULL;
125 static inline bool elf_sec__is_data(const GElf_Shdr *shdr,
126 const Elf_Data *secstrs)
128 return strstr(elf_sec__name(shdr, secstrs), "data") != NULL;
131 static bool elf_sec__is_a(GElf_Shdr *shdr, Elf_Data *secstrs,
136 return elf_sec__is_text(shdr, secstrs);
138 return elf_sec__is_data(shdr, secstrs);
144 static size_t elf_addr_to_index(Elf *elf, GElf_Addr addr)
150 while ((sec = elf_nextscn(elf, sec)) != NULL) {
151 gelf_getshdr(sec, &shdr);
153 if ((addr >= shdr.sh_addr) &&
154 (addr < (shdr.sh_addr + shdr.sh_size)))
163 Elf_Scn *elf_section_by_name(Elf *elf, GElf_Ehdr *ep,
164 GElf_Shdr *shp, const char *name, size_t *idx)
169 /* Elf is corrupted/truncated, avoid calling elf_strptr. */
170 if (!elf_rawdata(elf_getscn(elf, ep->e_shstrndx), NULL))
173 while ((sec = elf_nextscn(elf, sec)) != NULL) {
176 gelf_getshdr(sec, shp);
177 str = elf_strptr(elf, ep->e_shstrndx, shp->sh_name);
178 if (str && !strcmp(name, str)) {
189 #define elf_section__for_each_rel(reldata, pos, pos_mem, idx, nr_entries) \
190 for (idx = 0, pos = gelf_getrel(reldata, 0, &pos_mem); \
192 ++idx, pos = gelf_getrel(reldata, idx, &pos_mem))
194 #define elf_section__for_each_rela(reldata, pos, pos_mem, idx, nr_entries) \
195 for (idx = 0, pos = gelf_getrela(reldata, 0, &pos_mem); \
197 ++idx, pos = gelf_getrela(reldata, idx, &pos_mem))
200 * We need to check if we have a .dynsym, so that we can handle the
201 * .plt, synthesizing its symbols, that aren't on the symtabs (be it
202 * .dynsym or .symtab).
203 * And always look at the original dso, not at debuginfo packages, that
204 * have the PLT data stripped out (shdr_rel_plt.sh_type == SHT_NOBITS).
206 int dso__synthesize_plt_symbols(struct dso *dso, struct symsrc *ss, struct map *map,
207 symbol_filter_t filter)
209 uint32_t nr_rel_entries, idx;
214 GElf_Shdr shdr_rel_plt, shdr_dynsym;
215 Elf_Data *reldata, *syms, *symstrs;
216 Elf_Scn *scn_plt_rel, *scn_symstrs, *scn_dynsym;
219 char sympltname[1024];
221 int nr = 0, symidx, err = 0;
229 scn_dynsym = ss->dynsym;
230 shdr_dynsym = ss->dynshdr;
231 dynsym_idx = ss->dynsym_idx;
233 if (scn_dynsym == NULL)
236 scn_plt_rel = elf_section_by_name(elf, &ehdr, &shdr_rel_plt,
238 if (scn_plt_rel == NULL) {
239 scn_plt_rel = elf_section_by_name(elf, &ehdr, &shdr_rel_plt,
241 if (scn_plt_rel == NULL)
247 if (shdr_rel_plt.sh_link != dynsym_idx)
250 if (elf_section_by_name(elf, &ehdr, &shdr_plt, ".plt", NULL) == NULL)
254 * Fetch the relocation section to find the idxes to the GOT
255 * and the symbols in the .dynsym they refer to.
257 reldata = elf_getdata(scn_plt_rel, NULL);
261 syms = elf_getdata(scn_dynsym, NULL);
265 scn_symstrs = elf_getscn(elf, shdr_dynsym.sh_link);
266 if (scn_symstrs == NULL)
269 symstrs = elf_getdata(scn_symstrs, NULL);
273 if (symstrs->d_size == 0)
276 nr_rel_entries = shdr_rel_plt.sh_size / shdr_rel_plt.sh_entsize;
277 plt_offset = shdr_plt.sh_offset;
279 if (shdr_rel_plt.sh_type == SHT_RELA) {
280 GElf_Rela pos_mem, *pos;
282 elf_section__for_each_rela(reldata, pos, pos_mem, idx,
284 symidx = GELF_R_SYM(pos->r_info);
285 plt_offset += shdr_plt.sh_entsize;
286 gelf_getsym(syms, symidx, &sym);
287 snprintf(sympltname, sizeof(sympltname),
288 "%s@plt", elf_sym__name(&sym, symstrs));
290 f = symbol__new(plt_offset, shdr_plt.sh_entsize,
291 STB_GLOBAL, sympltname);
295 if (filter && filter(map, f))
298 symbols__insert(&dso->symbols[map->type], f);
302 } else if (shdr_rel_plt.sh_type == SHT_REL) {
303 GElf_Rel pos_mem, *pos;
304 elf_section__for_each_rel(reldata, pos, pos_mem, idx,
306 symidx = GELF_R_SYM(pos->r_info);
307 plt_offset += shdr_plt.sh_entsize;
308 gelf_getsym(syms, symidx, &sym);
309 snprintf(sympltname, sizeof(sympltname),
310 "%s@plt", elf_sym__name(&sym, symstrs));
312 f = symbol__new(plt_offset, shdr_plt.sh_entsize,
313 STB_GLOBAL, sympltname);
317 if (filter && filter(map, f))
320 symbols__insert(&dso->symbols[map->type], f);
330 pr_debug("%s: problems reading %s PLT info.\n",
331 __func__, dso->long_name);
336 * Align offset to 4 bytes as needed for note name and descriptor data.
338 #define NOTE_ALIGN(n) (((n) + 3) & -4U)
340 static int elf_read_build_id(Elf *elf, void *bf, size_t size)
350 if (size < BUILD_ID_SIZE)
357 if (gelf_getehdr(elf, &ehdr) == NULL) {
358 pr_err("%s: cannot get elf header.\n", __func__);
363 * Check following sections for notes:
364 * '.note.gnu.build-id'
366 * '.note' (VDSO specific)
369 sec = elf_section_by_name(elf, &ehdr, &shdr,
370 ".note.gnu.build-id", NULL);
374 sec = elf_section_by_name(elf, &ehdr, &shdr,
379 sec = elf_section_by_name(elf, &ehdr, &shdr,
388 data = elf_getdata(sec, NULL);
393 while (ptr < (data->d_buf + data->d_size)) {
394 GElf_Nhdr *nhdr = ptr;
395 size_t namesz = NOTE_ALIGN(nhdr->n_namesz),
396 descsz = NOTE_ALIGN(nhdr->n_descsz);
399 ptr += sizeof(*nhdr);
402 if (nhdr->n_type == NT_GNU_BUILD_ID &&
403 nhdr->n_namesz == sizeof("GNU")) {
404 if (memcmp(name, "GNU", sizeof("GNU")) == 0) {
405 size_t sz = min(size, descsz);
407 memset(bf + sz, 0, size - sz);
419 int filename__read_build_id(const char *filename, void *bf, size_t size)
424 if (size < BUILD_ID_SIZE)
427 fd = open(filename, O_RDONLY);
431 elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
433 pr_debug2("%s: cannot read %s ELF file.\n", __func__, filename);
437 err = elf_read_build_id(elf, bf, size);
446 int sysfs__read_build_id(const char *filename, void *build_id, size_t size)
450 if (size < BUILD_ID_SIZE)
453 fd = open(filename, O_RDONLY);
460 size_t namesz, descsz;
462 if (read(fd, &nhdr, sizeof(nhdr)) != sizeof(nhdr))
465 namesz = NOTE_ALIGN(nhdr.n_namesz);
466 descsz = NOTE_ALIGN(nhdr.n_descsz);
467 if (nhdr.n_type == NT_GNU_BUILD_ID &&
468 nhdr.n_namesz == sizeof("GNU")) {
469 if (read(fd, bf, namesz) != (ssize_t)namesz)
471 if (memcmp(bf, "GNU", sizeof("GNU")) == 0) {
472 size_t sz = min(descsz, size);
473 if (read(fd, build_id, sz) == (ssize_t)sz) {
474 memset(build_id + sz, 0, size - sz);
478 } else if (read(fd, bf, descsz) != (ssize_t)descsz)
481 int n = namesz + descsz;
482 if (read(fd, bf, n) != n)
491 int filename__read_debuglink(const char *filename, char *debuglink,
502 fd = open(filename, O_RDONLY);
506 elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
508 pr_debug2("%s: cannot read %s ELF file.\n", __func__, filename);
516 if (gelf_getehdr(elf, &ehdr) == NULL) {
517 pr_err("%s: cannot get elf header.\n", __func__);
521 sec = elf_section_by_name(elf, &ehdr, &shdr,
522 ".gnu_debuglink", NULL);
526 data = elf_getdata(sec, NULL);
530 /* the start of this section is a zero-terminated string */
531 strncpy(debuglink, data->d_buf, size);
543 static int dso__swap_init(struct dso *dso, unsigned char eidata)
545 static unsigned int const endian = 1;
547 dso->needs_swap = DSO_SWAP__NO;
551 /* We are big endian, DSO is little endian. */
552 if (*(unsigned char const *)&endian != 1)
553 dso->needs_swap = DSO_SWAP__YES;
557 /* We are little endian, DSO is big endian. */
558 if (*(unsigned char const *)&endian != 0)
559 dso->needs_swap = DSO_SWAP__YES;
563 pr_err("unrecognized DSO data encoding %d\n", eidata);
570 static int decompress_kmodule(struct dso *dso, const char *name,
571 enum dso_binary_type type)
574 const char *ext = strrchr(name, '.');
575 char tmpbuf[] = "/tmp/perf-kmod-XXXXXX";
577 if (type != DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE_COMP &&
578 type != DSO_BINARY_TYPE__GUEST_KMODULE_COMP &&
579 type != DSO_BINARY_TYPE__BUILD_ID_CACHE)
582 if (!ext || !is_supported_compression(ext + 1)) {
583 ext = strrchr(dso->name, '.');
584 if (!ext || !is_supported_compression(ext + 1))
588 fd = mkstemp(tmpbuf);
592 if (!decompress_to_file(ext + 1, name, fd)) {
602 bool symsrc__possibly_runtime(struct symsrc *ss)
604 return ss->dynsym || ss->opdsec;
607 bool symsrc__has_symtab(struct symsrc *ss)
609 return ss->symtab != NULL;
612 void symsrc__destroy(struct symsrc *ss)
619 int symsrc__init(struct symsrc *ss, struct dso *dso, const char *name,
620 enum dso_binary_type type)
627 if (dso__needs_decompress(dso))
628 fd = decompress_kmodule(dso, name, type);
630 fd = open(name, O_RDONLY);
635 elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
637 pr_debug("%s: cannot read %s ELF file.\n", __func__, name);
641 if (gelf_getehdr(elf, &ehdr) == NULL) {
642 pr_debug("%s: cannot get elf header.\n", __func__);
646 if (dso__swap_init(dso, ehdr.e_ident[EI_DATA]))
649 /* Always reject images with a mismatched build-id: */
650 if (dso->has_build_id) {
651 u8 build_id[BUILD_ID_SIZE];
653 if (elf_read_build_id(elf, build_id, BUILD_ID_SIZE) < 0)
656 if (!dso__build_id_equal(dso, build_id))
660 ss->is_64_bit = (gelf_getclass(elf) == ELFCLASS64);
662 ss->symtab = elf_section_by_name(elf, &ehdr, &ss->symshdr, ".symtab",
664 if (ss->symshdr.sh_type != SHT_SYMTAB)
668 ss->dynsym = elf_section_by_name(elf, &ehdr, &ss->dynshdr, ".dynsym",
670 if (ss->dynshdr.sh_type != SHT_DYNSYM)
674 ss->opdsec = elf_section_by_name(elf, &ehdr, &ss->opdshdr, ".opd",
676 if (ss->opdshdr.sh_type != SHT_PROGBITS)
679 if (dso->kernel == DSO_TYPE_USER) {
681 ss->adjust_symbols = (ehdr.e_type == ET_EXEC ||
682 ehdr.e_type == ET_REL ||
684 elf_section_by_name(elf, &ehdr, &shdr,
688 ss->adjust_symbols = ehdr.e_type == ET_EXEC ||
689 ehdr.e_type == ET_REL;
692 ss->name = strdup(name);
711 * ref_reloc_sym_not_found - has kernel relocation symbol been found.
712 * @kmap: kernel maps and relocation reference symbol
714 * This function returns %true if we are dealing with the kernel maps and the
715 * relocation reference symbol has not yet been found. Otherwise %false is
718 static bool ref_reloc_sym_not_found(struct kmap *kmap)
720 return kmap && kmap->ref_reloc_sym && kmap->ref_reloc_sym->name &&
721 !kmap->ref_reloc_sym->unrelocated_addr;
725 * ref_reloc - kernel relocation offset.
726 * @kmap: kernel maps and relocation reference symbol
728 * This function returns the offset of kernel addresses as determined by using
729 * the relocation reference symbol i.e. if the kernel has not been relocated
730 * then the return value is zero.
732 static u64 ref_reloc(struct kmap *kmap)
734 if (kmap && kmap->ref_reloc_sym &&
735 kmap->ref_reloc_sym->unrelocated_addr)
736 return kmap->ref_reloc_sym->addr -
737 kmap->ref_reloc_sym->unrelocated_addr;
741 static bool want_demangle(bool is_kernel_sym)
743 return is_kernel_sym ? symbol_conf.demangle_kernel : symbol_conf.demangle;
746 int dso__load_sym(struct dso *dso, struct map *map,
747 struct symsrc *syms_ss, struct symsrc *runtime_ss,
748 symbol_filter_t filter, int kmodule)
750 struct kmap *kmap = dso->kernel ? map__kmap(map) : NULL;
751 struct map *curr_map = map;
752 struct dso *curr_dso = dso;
753 Elf_Data *symstrs, *secstrs;
759 Elf_Data *syms, *opddata = NULL;
761 Elf_Scn *sec, *sec_strndx;
764 bool remap_kernel = false, adjust_kernel_syms = false;
766 dso->symtab_type = syms_ss->type;
767 dso->is_64_bit = syms_ss->is_64_bit;
768 dso->rel = syms_ss->ehdr.e_type == ET_REL;
771 * Modules may already have symbols from kallsyms, but those symbols
772 * have the wrong values for the dso maps, so remove them.
774 if (kmodule && syms_ss->symtab)
775 symbols__delete(&dso->symbols[map->type]);
777 if (!syms_ss->symtab) {
779 * If the vmlinux is stripped, fail so we will fall back
780 * to using kallsyms. The vmlinux runtime symbols aren't
786 syms_ss->symtab = syms_ss->dynsym;
787 syms_ss->symshdr = syms_ss->dynshdr;
791 ehdr = syms_ss->ehdr;
792 sec = syms_ss->symtab;
793 shdr = syms_ss->symshdr;
795 if (runtime_ss->opdsec)
796 opddata = elf_rawdata(runtime_ss->opdsec, NULL);
798 syms = elf_getdata(sec, NULL);
802 sec = elf_getscn(elf, shdr.sh_link);
806 symstrs = elf_getdata(sec, NULL);
810 sec_strndx = elf_getscn(runtime_ss->elf, runtime_ss->ehdr.e_shstrndx);
811 if (sec_strndx == NULL)
814 secstrs = elf_getdata(sec_strndx, NULL);
818 nr_syms = shdr.sh_size / shdr.sh_entsize;
820 memset(&sym, 0, sizeof(sym));
823 * The kernel relocation symbol is needed in advance in order to adjust
824 * kernel maps correctly.
826 if (ref_reloc_sym_not_found(kmap)) {
827 elf_symtab__for_each_symbol(syms, nr_syms, idx, sym) {
828 const char *elf_name = elf_sym__name(&sym, symstrs);
830 if (strcmp(elf_name, kmap->ref_reloc_sym->name))
832 kmap->ref_reloc_sym->unrelocated_addr = sym.st_value;
833 map->reloc = kmap->ref_reloc_sym->addr -
834 kmap->ref_reloc_sym->unrelocated_addr;
839 dso->adjust_symbols = runtime_ss->adjust_symbols || ref_reloc(kmap);
841 * Initial kernel and module mappings do not map to the dso. For
842 * function mappings, flag the fixups.
844 if (map->type == MAP__FUNCTION && (dso->kernel || kmodule)) {
846 adjust_kernel_syms = dso->adjust_symbols;
848 elf_symtab__for_each_symbol(syms, nr_syms, idx, sym) {
850 const char *elf_name = elf_sym__name(&sym, symstrs);
851 char *demangled = NULL;
852 int is_label = elf_sym__is_label(&sym);
853 const char *section_name;
854 bool used_opd = false;
856 if (!is_label && !elf_sym__is_a(&sym, map->type))
859 /* Reject ARM ELF "mapping symbols": these aren't unique and
860 * don't identify functions, so will confuse the profile
862 if (ehdr.e_machine == EM_ARM) {
863 if (!strcmp(elf_name, "$a") ||
864 !strcmp(elf_name, "$d") ||
865 !strcmp(elf_name, "$t"))
869 if (runtime_ss->opdsec && sym.st_shndx == runtime_ss->opdidx) {
870 u32 offset = sym.st_value - syms_ss->opdshdr.sh_addr;
871 u64 *opd = opddata->d_buf + offset;
872 sym.st_value = DSO__SWAP(dso, u64, *opd);
873 sym.st_shndx = elf_addr_to_index(runtime_ss->elf,
878 * When loading symbols in a data mapping, ABS symbols (which
879 * has a value of SHN_ABS in its st_shndx) failed at
880 * elf_getscn(). And it marks the loading as a failure so
881 * already loaded symbols cannot be fixed up.
883 * I'm not sure what should be done. Just ignore them for now.
886 if (sym.st_shndx == SHN_ABS)
889 sec = elf_getscn(runtime_ss->elf, sym.st_shndx);
893 gelf_getshdr(sec, &shdr);
895 if (is_label && !elf_sec__is_a(&shdr, secstrs, map->type))
898 section_name = elf_sec__name(&shdr, secstrs);
900 /* On ARM, symbols for thumb functions have 1 added to
901 * the symbol address as a flag - remove it */
902 if ((ehdr.e_machine == EM_ARM) &&
903 (map->type == MAP__FUNCTION) &&
907 if (dso->kernel || kmodule) {
908 char dso_name[PATH_MAX];
910 /* Adjust symbol to map to file offset */
911 if (adjust_kernel_syms)
912 sym.st_value -= shdr.sh_addr - shdr.sh_offset;
914 if (strcmp(section_name,
915 (curr_dso->short_name +
916 dso->short_name_len)) == 0)
919 if (strcmp(section_name, ".text") == 0) {
921 * The initial kernel mapping is based on
922 * kallsyms and identity maps. Overwrite it to
923 * map to the kernel dso.
925 if (remap_kernel && dso->kernel) {
926 remap_kernel = false;
927 map->start = shdr.sh_addr +
929 map->end = map->start + shdr.sh_size;
930 map->pgoff = shdr.sh_offset;
931 map->map_ip = map__map_ip;
932 map->unmap_ip = map__unmap_ip;
933 /* Ensure maps are correctly ordered */
934 map_groups__remove(kmap->kmaps, map);
935 map_groups__insert(kmap->kmaps, map);
939 * The initial module mapping is based on
940 * /proc/modules mapped to offset zero.
941 * Overwrite it to map to the module dso.
943 if (remap_kernel && kmodule) {
944 remap_kernel = false;
945 map->pgoff = shdr.sh_offset;
956 snprintf(dso_name, sizeof(dso_name),
957 "%s%s", dso->short_name, section_name);
959 curr_map = map_groups__find_by_name(kmap->kmaps, map->type, dso_name);
960 if (curr_map == NULL) {
961 u64 start = sym.st_value;
964 start += map->start + shdr.sh_offset;
966 curr_dso = dso__new(dso_name);
967 if (curr_dso == NULL)
969 curr_dso->kernel = dso->kernel;
970 curr_dso->long_name = dso->long_name;
971 curr_dso->long_name_len = dso->long_name_len;
972 curr_map = map__new2(start, curr_dso,
974 if (curr_map == NULL) {
975 dso__delete(curr_dso);
978 if (adjust_kernel_syms) {
979 curr_map->start = shdr.sh_addr +
981 curr_map->end = curr_map->start +
983 curr_map->pgoff = shdr.sh_offset;
985 curr_map->map_ip = identity__map_ip;
986 curr_map->unmap_ip = identity__map_ip;
988 curr_dso->symtab_type = dso->symtab_type;
989 map_groups__insert(kmap->kmaps, curr_map);
991 * The new DSO should go to the kernel DSOS
993 dsos__add(&map->groups->machine->kernel_dsos,
995 dso__set_loaded(curr_dso, map->type);
997 curr_dso = curr_map->dso;
1002 if ((used_opd && runtime_ss->adjust_symbols)
1003 || (!used_opd && syms_ss->adjust_symbols)) {
1004 pr_debug4("%s: adjusting symbol: st_value: %#" PRIx64 " "
1005 "sh_addr: %#" PRIx64 " sh_offset: %#" PRIx64 "\n", __func__,
1006 (u64)sym.st_value, (u64)shdr.sh_addr,
1007 (u64)shdr.sh_offset);
1008 sym.st_value -= shdr.sh_addr - shdr.sh_offset;
1012 * We need to figure out if the object was created from C++ sources
1013 * DWARF DW_compile_unit has this, but we don't always have access
1016 if (want_demangle(dso->kernel || kmodule)) {
1017 int demangle_flags = DMGL_NO_OPTS;
1019 demangle_flags = DMGL_PARAMS | DMGL_ANSI;
1021 demangled = bfd_demangle(NULL, elf_name, demangle_flags);
1022 if (demangled != NULL)
1023 elf_name = demangled;
1025 f = symbol__new(sym.st_value, sym.st_size,
1026 GELF_ST_BIND(sym.st_info), elf_name);
1031 if (filter && filter(curr_map, f))
1034 symbols__insert(&curr_dso->symbols[curr_map->type], f);
1040 * For misannotated, zeroed, ASM function sizes.
1043 symbols__fixup_duplicate(&dso->symbols[map->type]);
1044 symbols__fixup_end(&dso->symbols[map->type]);
1047 * We need to fixup this here too because we create new
1048 * maps here, for things like vsyscall sections.
1050 __map_groups__fixup_end(kmap->kmaps, map->type);
1058 static int elf_read_maps(Elf *elf, bool exe, mapfn_t mapfn, void *data)
1065 if (elf_getphdrnum(elf, &phdrnum))
1068 for (i = 0; i < phdrnum; i++) {
1069 if (gelf_getphdr(elf, i, &phdr) == NULL)
1071 if (phdr.p_type != PT_LOAD)
1074 if (!(phdr.p_flags & PF_X))
1077 if (!(phdr.p_flags & PF_R))
1080 sz = min(phdr.p_memsz, phdr.p_filesz);
1083 err = mapfn(phdr.p_vaddr, sz, phdr.p_offset, data);
1090 int file__read_maps(int fd, bool exe, mapfn_t mapfn, void *data,
1096 elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
1101 *is_64_bit = (gelf_getclass(elf) == ELFCLASS64);
1103 err = elf_read_maps(elf, exe, mapfn, data);
1109 enum dso_type dso__type_fd(int fd)
1111 enum dso_type dso_type = DSO__TYPE_UNKNOWN;
1116 elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
1121 if (ek != ELF_K_ELF)
1124 if (gelf_getclass(elf) == ELFCLASS64) {
1125 dso_type = DSO__TYPE_64BIT;
1129 if (gelf_getehdr(elf, &ehdr) == NULL)
1132 if (ehdr.e_machine == EM_X86_64)
1133 dso_type = DSO__TYPE_X32BIT;
1135 dso_type = DSO__TYPE_32BIT;
1142 static int copy_bytes(int from, off_t from_offs, int to, off_t to_offs, u64 len)
1147 char *buf = malloc(page_size);
1152 if (lseek(to, to_offs, SEEK_SET) != to_offs)
1155 if (lseek(from, from_offs, SEEK_SET) != from_offs)
1162 /* Use read because mmap won't work on proc files */
1163 r = read(from, buf, n);
1169 r = write(to, buf, n);
1190 static int kcore__open(struct kcore *kcore, const char *filename)
1194 kcore->fd = open(filename, O_RDONLY);
1195 if (kcore->fd == -1)
1198 kcore->elf = elf_begin(kcore->fd, ELF_C_READ, NULL);
1202 kcore->elfclass = gelf_getclass(kcore->elf);
1203 if (kcore->elfclass == ELFCLASSNONE)
1206 ehdr = gelf_getehdr(kcore->elf, &kcore->ehdr);
1213 elf_end(kcore->elf);
1219 static int kcore__init(struct kcore *kcore, char *filename, int elfclass,
1224 kcore->elfclass = elfclass;
1227 kcore->fd = mkstemp(filename);
1229 kcore->fd = open(filename, O_WRONLY | O_CREAT | O_EXCL, 0400);
1230 if (kcore->fd == -1)
1233 kcore->elf = elf_begin(kcore->fd, ELF_C_WRITE, NULL);
1237 if (!gelf_newehdr(kcore->elf, elfclass))
1240 ehdr = gelf_getehdr(kcore->elf, &kcore->ehdr);
1247 elf_end(kcore->elf);
1254 static void kcore__close(struct kcore *kcore)
1256 elf_end(kcore->elf);
1260 static int kcore__copy_hdr(struct kcore *from, struct kcore *to, size_t count)
1262 GElf_Ehdr *ehdr = &to->ehdr;
1263 GElf_Ehdr *kehdr = &from->ehdr;
1265 memcpy(ehdr->e_ident, kehdr->e_ident, EI_NIDENT);
1266 ehdr->e_type = kehdr->e_type;
1267 ehdr->e_machine = kehdr->e_machine;
1268 ehdr->e_version = kehdr->e_version;
1271 ehdr->e_flags = kehdr->e_flags;
1272 ehdr->e_phnum = count;
1273 ehdr->e_shentsize = 0;
1275 ehdr->e_shstrndx = 0;
1277 if (from->elfclass == ELFCLASS32) {
1278 ehdr->e_phoff = sizeof(Elf32_Ehdr);
1279 ehdr->e_ehsize = sizeof(Elf32_Ehdr);
1280 ehdr->e_phentsize = sizeof(Elf32_Phdr);
1282 ehdr->e_phoff = sizeof(Elf64_Ehdr);
1283 ehdr->e_ehsize = sizeof(Elf64_Ehdr);
1284 ehdr->e_phentsize = sizeof(Elf64_Phdr);
1287 if (!gelf_update_ehdr(to->elf, ehdr))
1290 if (!gelf_newphdr(to->elf, count))
1296 static int kcore__add_phdr(struct kcore *kcore, int idx, off_t offset,
1302 phdr = gelf_getphdr(kcore->elf, idx, &gphdr);
1306 phdr->p_type = PT_LOAD;
1307 phdr->p_flags = PF_R | PF_W | PF_X;
1308 phdr->p_offset = offset;
1309 phdr->p_vaddr = addr;
1311 phdr->p_filesz = len;
1312 phdr->p_memsz = len;
1313 phdr->p_align = page_size;
1315 if (!gelf_update_phdr(kcore->elf, idx, phdr))
1321 static off_t kcore__write(struct kcore *kcore)
1323 return elf_update(kcore->elf, ELF_C_WRITE);
1332 struct kcore_copy_info {
1338 u64 last_module_symbol;
1339 struct phdr_data kernel_map;
1340 struct phdr_data modules_map;
1343 static int kcore_copy__process_kallsyms(void *arg, const char *name, char type,
1346 struct kcore_copy_info *kci = arg;
1348 if (!symbol_type__is_a(type, MAP__FUNCTION))
1351 if (strchr(name, '[')) {
1352 if (start > kci->last_module_symbol)
1353 kci->last_module_symbol = start;
1357 if (!kci->first_symbol || start < kci->first_symbol)
1358 kci->first_symbol = start;
1360 if (!kci->last_symbol || start > kci->last_symbol)
1361 kci->last_symbol = start;
1363 if (!strcmp(name, "_stext")) {
1368 if (!strcmp(name, "_etext")) {
1376 static int kcore_copy__parse_kallsyms(struct kcore_copy_info *kci,
1379 char kallsyms_filename[PATH_MAX];
1381 scnprintf(kallsyms_filename, PATH_MAX, "%s/kallsyms", dir);
1383 if (symbol__restricted_filename(kallsyms_filename, "/proc/kallsyms"))
1386 if (kallsyms__parse(kallsyms_filename, kci,
1387 kcore_copy__process_kallsyms) < 0)
1393 static int kcore_copy__process_modules(void *arg,
1394 const char *name __maybe_unused,
1397 struct kcore_copy_info *kci = arg;
1399 if (!kci->first_module || start < kci->first_module)
1400 kci->first_module = start;
1405 static int kcore_copy__parse_modules(struct kcore_copy_info *kci,
1408 char modules_filename[PATH_MAX];
1410 scnprintf(modules_filename, PATH_MAX, "%s/modules", dir);
1412 if (symbol__restricted_filename(modules_filename, "/proc/modules"))
1415 if (modules__parse(modules_filename, kci,
1416 kcore_copy__process_modules) < 0)
1422 static void kcore_copy__map(struct phdr_data *p, u64 start, u64 end, u64 pgoff,
1425 if (p->addr || s < start || s >= end)
1429 p->offset = (s - start) + pgoff;
1430 p->len = e < end ? e - s : end - s;
1433 static int kcore_copy__read_map(u64 start, u64 len, u64 pgoff, void *data)
1435 struct kcore_copy_info *kci = data;
1436 u64 end = start + len;
1438 kcore_copy__map(&kci->kernel_map, start, end, pgoff, kci->stext,
1441 kcore_copy__map(&kci->modules_map, start, end, pgoff, kci->first_module,
1442 kci->last_module_symbol);
1447 static int kcore_copy__read_maps(struct kcore_copy_info *kci, Elf *elf)
1449 if (elf_read_maps(elf, true, kcore_copy__read_map, kci) < 0)
1455 static int kcore_copy__calc_maps(struct kcore_copy_info *kci, const char *dir,
1458 if (kcore_copy__parse_kallsyms(kci, dir))
1461 if (kcore_copy__parse_modules(kci, dir))
1465 kci->stext = round_down(kci->stext, page_size);
1467 kci->stext = round_down(kci->first_symbol, page_size);
1470 kci->etext = round_up(kci->etext, page_size);
1471 } else if (kci->last_symbol) {
1472 kci->etext = round_up(kci->last_symbol, page_size);
1473 kci->etext += page_size;
1476 kci->first_module = round_down(kci->first_module, page_size);
1478 if (kci->last_module_symbol) {
1479 kci->last_module_symbol = round_up(kci->last_module_symbol,
1481 kci->last_module_symbol += page_size;
1484 if (!kci->stext || !kci->etext)
1487 if (kci->first_module && !kci->last_module_symbol)
1490 return kcore_copy__read_maps(kci, elf);
1493 static int kcore_copy__copy_file(const char *from_dir, const char *to_dir,
1496 char from_filename[PATH_MAX];
1497 char to_filename[PATH_MAX];
1499 scnprintf(from_filename, PATH_MAX, "%s/%s", from_dir, name);
1500 scnprintf(to_filename, PATH_MAX, "%s/%s", to_dir, name);
1502 return copyfile_mode(from_filename, to_filename, 0400);
1505 static int kcore_copy__unlink(const char *dir, const char *name)
1507 char filename[PATH_MAX];
1509 scnprintf(filename, PATH_MAX, "%s/%s", dir, name);
1511 return unlink(filename);
1514 static int kcore_copy__compare_fds(int from, int to)
1522 buf_from = malloc(page_size);
1523 buf_to = malloc(page_size);
1524 if (!buf_from || !buf_to)
1528 /* Use read because mmap won't work on proc files */
1529 ret = read(from, buf_from, page_size);
1538 if (readn(to, buf_to, len) != (int)len)
1541 if (memcmp(buf_from, buf_to, len))
1552 static int kcore_copy__compare_files(const char *from_filename,
1553 const char *to_filename)
1555 int from, to, err = -1;
1557 from = open(from_filename, O_RDONLY);
1561 to = open(to_filename, O_RDONLY);
1563 goto out_close_from;
1565 err = kcore_copy__compare_fds(from, to);
1573 static int kcore_copy__compare_file(const char *from_dir, const char *to_dir,
1576 char from_filename[PATH_MAX];
1577 char to_filename[PATH_MAX];
1579 scnprintf(from_filename, PATH_MAX, "%s/%s", from_dir, name);
1580 scnprintf(to_filename, PATH_MAX, "%s/%s", to_dir, name);
1582 return kcore_copy__compare_files(from_filename, to_filename);
1586 * kcore_copy - copy kallsyms, modules and kcore from one directory to another.
1587 * @from_dir: from directory
1588 * @to_dir: to directory
1590 * This function copies kallsyms, modules and kcore files from one directory to
1591 * another. kallsyms and modules are copied entirely. Only code segments are
1592 * copied from kcore. It is assumed that two segments suffice: one for the
1593 * kernel proper and one for all the modules. The code segments are determined
1594 * from kallsyms and modules files. The kernel map starts at _stext or the
1595 * lowest function symbol, and ends at _etext or the highest function symbol.
1596 * The module map starts at the lowest module address and ends at the highest
1597 * module symbol. Start addresses are rounded down to the nearest page. End
1598 * addresses are rounded up to the nearest page. An extra page is added to the
1599 * highest kernel symbol and highest module symbol to, hopefully, encompass that
1600 * symbol too. Because it contains only code sections, the resulting kcore is
1601 * unusual. One significant peculiarity is that the mapping (start -> pgoff)
1602 * is not the same for the kernel map and the modules map. That happens because
1603 * the data is copied adjacently whereas the original kcore has gaps. Finally,
1604 * kallsyms and modules files are compared with their copies to check that
1605 * modules have not been loaded or unloaded while the copies were taking place.
1607 * Return: %0 on success, %-1 on failure.
1609 int kcore_copy(const char *from_dir, const char *to_dir)
1612 struct kcore extract;
1614 int idx = 0, err = -1;
1615 off_t offset = page_size, sz, modules_offset = 0;
1616 struct kcore_copy_info kci = { .stext = 0, };
1617 char kcore_filename[PATH_MAX];
1618 char extract_filename[PATH_MAX];
1620 if (kcore_copy__copy_file(from_dir, to_dir, "kallsyms"))
1623 if (kcore_copy__copy_file(from_dir, to_dir, "modules"))
1624 goto out_unlink_kallsyms;
1626 scnprintf(kcore_filename, PATH_MAX, "%s/kcore", from_dir);
1627 scnprintf(extract_filename, PATH_MAX, "%s/kcore", to_dir);
1629 if (kcore__open(&kcore, kcore_filename))
1630 goto out_unlink_modules;
1632 if (kcore_copy__calc_maps(&kci, from_dir, kcore.elf))
1633 goto out_kcore_close;
1635 if (kcore__init(&extract, extract_filename, kcore.elfclass, false))
1636 goto out_kcore_close;
1638 if (!kci.modules_map.addr)
1641 if (kcore__copy_hdr(&kcore, &extract, count))
1642 goto out_extract_close;
1644 if (kcore__add_phdr(&extract, idx++, offset, kci.kernel_map.addr,
1645 kci.kernel_map.len))
1646 goto out_extract_close;
1648 if (kci.modules_map.addr) {
1649 modules_offset = offset + kci.kernel_map.len;
1650 if (kcore__add_phdr(&extract, idx, modules_offset,
1651 kci.modules_map.addr, kci.modules_map.len))
1652 goto out_extract_close;
1655 sz = kcore__write(&extract);
1656 if (sz < 0 || sz > offset)
1657 goto out_extract_close;
1659 if (copy_bytes(kcore.fd, kci.kernel_map.offset, extract.fd, offset,
1660 kci.kernel_map.len))
1661 goto out_extract_close;
1663 if (modules_offset && copy_bytes(kcore.fd, kci.modules_map.offset,
1664 extract.fd, modules_offset,
1665 kci.modules_map.len))
1666 goto out_extract_close;
1668 if (kcore_copy__compare_file(from_dir, to_dir, "modules"))
1669 goto out_extract_close;
1671 if (kcore_copy__compare_file(from_dir, to_dir, "kallsyms"))
1672 goto out_extract_close;
1677 kcore__close(&extract);
1679 unlink(extract_filename);
1681 kcore__close(&kcore);
1684 kcore_copy__unlink(to_dir, "modules");
1685 out_unlink_kallsyms:
1687 kcore_copy__unlink(to_dir, "kallsyms");
1692 int kcore_extract__create(struct kcore_extract *kce)
1695 struct kcore extract;
1697 int idx = 0, err = -1;
1698 off_t offset = page_size, sz;
1700 if (kcore__open(&kcore, kce->kcore_filename))
1703 strcpy(kce->extract_filename, PERF_KCORE_EXTRACT);
1704 if (kcore__init(&extract, kce->extract_filename, kcore.elfclass, true))
1705 goto out_kcore_close;
1707 if (kcore__copy_hdr(&kcore, &extract, count))
1708 goto out_extract_close;
1710 if (kcore__add_phdr(&extract, idx, offset, kce->addr, kce->len))
1711 goto out_extract_close;
1713 sz = kcore__write(&extract);
1714 if (sz < 0 || sz > offset)
1715 goto out_extract_close;
1717 if (copy_bytes(kcore.fd, kce->offs, extract.fd, offset, kce->len))
1718 goto out_extract_close;
1723 kcore__close(&extract);
1725 unlink(kce->extract_filename);
1727 kcore__close(&kcore);
1732 void kcore_extract__delete(struct kcore_extract *kce)
1734 unlink(kce->extract_filename);
1737 void symbol__elf_init(void)
1739 elf_version(EV_CURRENT);