1 // SPDX-License-Identifier: GPL-2.0
10 #include "map_groups.h"
12 #include "demangle-java.h"
13 #include "demangle-rust.h"
18 #include "sane_ctype.h"
19 #include <symbol/kallsyms.h>
22 #define EM_AARCH64 183 /* ARM 64 bit */
25 #ifndef ELF32_ST_VISIBILITY
26 #define ELF32_ST_VISIBILITY(o) ((o) & 0x03)
29 /* For ELF64 the definitions are the same. */
30 #ifndef ELF64_ST_VISIBILITY
31 #define ELF64_ST_VISIBILITY(o) ELF32_ST_VISIBILITY (o)
34 /* How to extract information held in the st_other field. */
35 #ifndef GELF_ST_VISIBILITY
36 #define GELF_ST_VISIBILITY(val) ELF64_ST_VISIBILITY (val)
39 typedef Elf64_Nhdr GElf_Nhdr;
41 #ifdef HAVE_CPLUS_DEMANGLE_SUPPORT
42 extern char *cplus_demangle(const char *, int);
44 static inline char *bfd_demangle(void __maybe_unused *v, const char *c, int i)
46 return cplus_demangle(c, i);
50 static inline char *bfd_demangle(void __maybe_unused *v,
51 const char __maybe_unused *c,
57 #define PACKAGE 'perf'
62 #ifndef HAVE_ELF_GETPHDRNUM_SUPPORT
63 static int elf_getphdrnum(Elf *elf, size_t *dst)
68 ehdr = gelf_getehdr(elf, &gehdr);
78 #ifndef HAVE_ELF_GETSHDRSTRNDX_SUPPORT
79 static int elf_getshdrstrndx(Elf *elf __maybe_unused, size_t *dst __maybe_unused)
81 pr_err("%s: update your libelf to > 0.140, this one lacks elf_getshdrstrndx().\n", __func__);
86 #ifndef NT_GNU_BUILD_ID
87 #define NT_GNU_BUILD_ID 3
91 * elf_symtab__for_each_symbol - iterate thru all the symbols
93 * @syms: struct elf_symtab instance to iterate
95 * @sym: GElf_Sym iterator
97 #define elf_symtab__for_each_symbol(syms, nr_syms, idx, sym) \
98 for (idx = 0, gelf_getsym(syms, idx, &sym);\
100 idx++, gelf_getsym(syms, idx, &sym))
102 static inline uint8_t elf_sym__type(const GElf_Sym *sym)
104 return GELF_ST_TYPE(sym->st_info);
107 static inline uint8_t elf_sym__visibility(const GElf_Sym *sym)
109 return GELF_ST_VISIBILITY(sym->st_other);
112 #ifndef STT_GNU_IFUNC
113 #define STT_GNU_IFUNC 10
116 static inline int elf_sym__is_function(const GElf_Sym *sym)
118 return (elf_sym__type(sym) == STT_FUNC ||
119 elf_sym__type(sym) == STT_GNU_IFUNC) &&
121 sym->st_shndx != SHN_UNDEF;
124 static inline bool elf_sym__is_object(const GElf_Sym *sym)
126 return elf_sym__type(sym) == STT_OBJECT &&
128 sym->st_shndx != SHN_UNDEF;
131 static inline int elf_sym__is_label(const GElf_Sym *sym)
133 return elf_sym__type(sym) == STT_NOTYPE &&
135 sym->st_shndx != SHN_UNDEF &&
136 sym->st_shndx != SHN_ABS &&
137 elf_sym__visibility(sym) != STV_HIDDEN &&
138 elf_sym__visibility(sym) != STV_INTERNAL;
141 static bool elf_sym__filter(GElf_Sym *sym)
143 return elf_sym__is_function(sym) || elf_sym__is_object(sym);
146 static inline const char *elf_sym__name(const GElf_Sym *sym,
147 const Elf_Data *symstrs)
149 return symstrs->d_buf + sym->st_name;
152 static inline const char *elf_sec__name(const GElf_Shdr *shdr,
153 const Elf_Data *secstrs)
155 return secstrs->d_buf + shdr->sh_name;
158 static inline int elf_sec__is_text(const GElf_Shdr *shdr,
159 const Elf_Data *secstrs)
161 return strstr(elf_sec__name(shdr, secstrs), "text") != NULL;
164 static inline bool elf_sec__is_data(const GElf_Shdr *shdr,
165 const Elf_Data *secstrs)
167 return strstr(elf_sec__name(shdr, secstrs), "data") != NULL;
170 static bool elf_sec__filter(GElf_Shdr *shdr, Elf_Data *secstrs)
172 return elf_sec__is_text(shdr, secstrs) ||
173 elf_sec__is_data(shdr, secstrs);
176 static size_t elf_addr_to_index(Elf *elf, GElf_Addr addr)
182 while ((sec = elf_nextscn(elf, sec)) != NULL) {
183 gelf_getshdr(sec, &shdr);
185 if ((addr >= shdr.sh_addr) &&
186 (addr < (shdr.sh_addr + shdr.sh_size)))
195 Elf_Scn *elf_section_by_name(Elf *elf, GElf_Ehdr *ep,
196 GElf_Shdr *shp, const char *name, size_t *idx)
201 /* Elf is corrupted/truncated, avoid calling elf_strptr. */
202 if (!elf_rawdata(elf_getscn(elf, ep->e_shstrndx), NULL))
205 while ((sec = elf_nextscn(elf, sec)) != NULL) {
208 gelf_getshdr(sec, shp);
209 str = elf_strptr(elf, ep->e_shstrndx, shp->sh_name);
210 if (str && !strcmp(name, str)) {
221 static bool want_demangle(bool is_kernel_sym)
223 return is_kernel_sym ? symbol_conf.demangle_kernel : symbol_conf.demangle;
226 static char *demangle_sym(struct dso *dso, int kmodule, const char *elf_name)
228 int demangle_flags = verbose > 0 ? (DMGL_PARAMS | DMGL_ANSI) : DMGL_NO_OPTS;
229 char *demangled = NULL;
232 * We need to figure out if the object was created from C++ sources
233 * DWARF DW_compile_unit has this, but we don't always have access
236 if (!want_demangle(dso->kernel || kmodule))
239 demangled = bfd_demangle(NULL, elf_name, demangle_flags);
240 if (demangled == NULL)
241 demangled = java_demangle_sym(elf_name, JAVA_DEMANGLE_NORET);
242 else if (rust_is_mangled(demangled))
244 * Input to Rust demangling is the BFD-demangled
245 * name which it Rust-demangles in place.
247 rust_demangle_sym(demangled);
252 #define elf_section__for_each_rel(reldata, pos, pos_mem, idx, nr_entries) \
253 for (idx = 0, pos = gelf_getrel(reldata, 0, &pos_mem); \
255 ++idx, pos = gelf_getrel(reldata, idx, &pos_mem))
257 #define elf_section__for_each_rela(reldata, pos, pos_mem, idx, nr_entries) \
258 for (idx = 0, pos = gelf_getrela(reldata, 0, &pos_mem); \
260 ++idx, pos = gelf_getrela(reldata, idx, &pos_mem))
263 * We need to check if we have a .dynsym, so that we can handle the
264 * .plt, synthesizing its symbols, that aren't on the symtabs (be it
265 * .dynsym or .symtab).
266 * And always look at the original dso, not at debuginfo packages, that
267 * have the PLT data stripped out (shdr_rel_plt.sh_type == SHT_NOBITS).
269 int dso__synthesize_plt_symbols(struct dso *dso, struct symsrc *ss)
271 uint32_t nr_rel_entries, idx;
273 u64 plt_offset, plt_header_size, plt_entry_size;
276 GElf_Shdr shdr_rel_plt, shdr_dynsym;
277 Elf_Data *reldata, *syms, *symstrs;
278 Elf_Scn *scn_plt_rel, *scn_symstrs, *scn_dynsym;
281 char sympltname[1024];
283 int nr = 0, symidx, err = 0;
291 scn_dynsym = ss->dynsym;
292 shdr_dynsym = ss->dynshdr;
293 dynsym_idx = ss->dynsym_idx;
295 if (scn_dynsym == NULL)
298 scn_plt_rel = elf_section_by_name(elf, &ehdr, &shdr_rel_plt,
300 if (scn_plt_rel == NULL) {
301 scn_plt_rel = elf_section_by_name(elf, &ehdr, &shdr_rel_plt,
303 if (scn_plt_rel == NULL)
309 if (shdr_rel_plt.sh_link != dynsym_idx)
312 if (elf_section_by_name(elf, &ehdr, &shdr_plt, ".plt", NULL) == NULL)
316 * Fetch the relocation section to find the idxes to the GOT
317 * and the symbols in the .dynsym they refer to.
319 reldata = elf_getdata(scn_plt_rel, NULL);
323 syms = elf_getdata(scn_dynsym, NULL);
327 scn_symstrs = elf_getscn(elf, shdr_dynsym.sh_link);
328 if (scn_symstrs == NULL)
331 symstrs = elf_getdata(scn_symstrs, NULL);
335 if (symstrs->d_size == 0)
338 nr_rel_entries = shdr_rel_plt.sh_size / shdr_rel_plt.sh_entsize;
339 plt_offset = shdr_plt.sh_offset;
340 switch (ehdr.e_machine) {
342 plt_header_size = 20;
347 plt_header_size = 32;
352 plt_header_size = 48;
357 plt_header_size = 128;
361 default: /* FIXME: s390/alpha/mips/parisc/poperpc/sh/xtensa need to be checked */
362 plt_header_size = shdr_plt.sh_entsize;
363 plt_entry_size = shdr_plt.sh_entsize;
366 plt_offset += plt_header_size;
368 if (shdr_rel_plt.sh_type == SHT_RELA) {
369 GElf_Rela pos_mem, *pos;
371 elf_section__for_each_rela(reldata, pos, pos_mem, idx,
373 const char *elf_name = NULL;
374 char *demangled = NULL;
375 symidx = GELF_R_SYM(pos->r_info);
376 gelf_getsym(syms, symidx, &sym);
378 elf_name = elf_sym__name(&sym, symstrs);
379 demangled = demangle_sym(dso, 0, elf_name);
380 if (demangled != NULL)
381 elf_name = demangled;
382 snprintf(sympltname, sizeof(sympltname),
386 f = symbol__new(plt_offset, plt_entry_size,
387 STB_GLOBAL, STT_FUNC, sympltname);
391 plt_offset += plt_entry_size;
392 symbols__insert(&dso->symbols, f);
395 } else if (shdr_rel_plt.sh_type == SHT_REL) {
396 GElf_Rel pos_mem, *pos;
397 elf_section__for_each_rel(reldata, pos, pos_mem, idx,
399 const char *elf_name = NULL;
400 char *demangled = NULL;
401 symidx = GELF_R_SYM(pos->r_info);
402 gelf_getsym(syms, symidx, &sym);
404 elf_name = elf_sym__name(&sym, symstrs);
405 demangled = demangle_sym(dso, 0, elf_name);
406 if (demangled != NULL)
407 elf_name = demangled;
408 snprintf(sympltname, sizeof(sympltname),
412 f = symbol__new(plt_offset, plt_entry_size,
413 STB_GLOBAL, STT_FUNC, sympltname);
417 plt_offset += plt_entry_size;
418 symbols__insert(&dso->symbols, f);
427 pr_debug("%s: problems reading %s PLT info.\n",
428 __func__, dso->long_name);
432 char *dso__demangle_sym(struct dso *dso, int kmodule, const char *elf_name)
434 return demangle_sym(dso, kmodule, elf_name);
438 * Align offset to 4 bytes as needed for note name and descriptor data.
440 #define NOTE_ALIGN(n) (((n) + 3) & -4U)
442 static int elf_read_build_id(Elf *elf, void *bf, size_t size)
452 if (size < BUILD_ID_SIZE)
459 if (gelf_getehdr(elf, &ehdr) == NULL) {
460 pr_err("%s: cannot get elf header.\n", __func__);
465 * Check following sections for notes:
466 * '.note.gnu.build-id'
468 * '.note' (VDSO specific)
471 sec = elf_section_by_name(elf, &ehdr, &shdr,
472 ".note.gnu.build-id", NULL);
476 sec = elf_section_by_name(elf, &ehdr, &shdr,
481 sec = elf_section_by_name(elf, &ehdr, &shdr,
490 data = elf_getdata(sec, NULL);
495 while (ptr < (data->d_buf + data->d_size)) {
496 GElf_Nhdr *nhdr = ptr;
497 size_t namesz = NOTE_ALIGN(nhdr->n_namesz),
498 descsz = NOTE_ALIGN(nhdr->n_descsz);
501 ptr += sizeof(*nhdr);
504 if (nhdr->n_type == NT_GNU_BUILD_ID &&
505 nhdr->n_namesz == sizeof("GNU")) {
506 if (memcmp(name, "GNU", sizeof("GNU")) == 0) {
507 size_t sz = min(size, descsz);
509 memset(bf + sz, 0, size - sz);
521 int filename__read_build_id(const char *filename, void *bf, size_t size)
526 if (size < BUILD_ID_SIZE)
529 fd = open(filename, O_RDONLY);
533 elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
535 pr_debug2("%s: cannot read %s ELF file.\n", __func__, filename);
539 err = elf_read_build_id(elf, bf, size);
548 int sysfs__read_build_id(const char *filename, void *build_id, size_t size)
552 if (size < BUILD_ID_SIZE)
555 fd = open(filename, O_RDONLY);
562 size_t namesz, descsz;
564 if (read(fd, &nhdr, sizeof(nhdr)) != sizeof(nhdr))
567 namesz = NOTE_ALIGN(nhdr.n_namesz);
568 descsz = NOTE_ALIGN(nhdr.n_descsz);
569 if (nhdr.n_type == NT_GNU_BUILD_ID &&
570 nhdr.n_namesz == sizeof("GNU")) {
571 if (read(fd, bf, namesz) != (ssize_t)namesz)
573 if (memcmp(bf, "GNU", sizeof("GNU")) == 0) {
574 size_t sz = min(descsz, size);
575 if (read(fd, build_id, sz) == (ssize_t)sz) {
576 memset(build_id + sz, 0, size - sz);
580 } else if (read(fd, bf, descsz) != (ssize_t)descsz)
583 int n = namesz + descsz;
585 if (n > (int)sizeof(bf)) {
587 pr_debug("%s: truncating reading of build id in sysfs file %s: n_namesz=%u, n_descsz=%u.\n",
588 __func__, filename, nhdr.n_namesz, nhdr.n_descsz);
590 if (read(fd, bf, n) != n)
599 int filename__read_debuglink(const char *filename, char *debuglink,
610 fd = open(filename, O_RDONLY);
614 elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
616 pr_debug2("%s: cannot read %s ELF file.\n", __func__, filename);
624 if (gelf_getehdr(elf, &ehdr) == NULL) {
625 pr_err("%s: cannot get elf header.\n", __func__);
629 sec = elf_section_by_name(elf, &ehdr, &shdr,
630 ".gnu_debuglink", NULL);
634 data = elf_getdata(sec, NULL);
638 /* the start of this section is a zero-terminated string */
639 strncpy(debuglink, data->d_buf, size);
651 static int dso__swap_init(struct dso *dso, unsigned char eidata)
653 static unsigned int const endian = 1;
655 dso->needs_swap = DSO_SWAP__NO;
659 /* We are big endian, DSO is little endian. */
660 if (*(unsigned char const *)&endian != 1)
661 dso->needs_swap = DSO_SWAP__YES;
665 /* We are little endian, DSO is big endian. */
666 if (*(unsigned char const *)&endian != 0)
667 dso->needs_swap = DSO_SWAP__YES;
671 pr_err("unrecognized DSO data encoding %d\n", eidata);
678 bool symsrc__possibly_runtime(struct symsrc *ss)
680 return ss->dynsym || ss->opdsec;
683 bool symsrc__has_symtab(struct symsrc *ss)
685 return ss->symtab != NULL;
688 void symsrc__destroy(struct symsrc *ss)
695 bool __weak elf__needs_adjust_symbols(GElf_Ehdr ehdr)
697 return ehdr.e_type == ET_EXEC || ehdr.e_type == ET_REL;
700 int symsrc__init(struct symsrc *ss, struct dso *dso, const char *name,
701 enum dso_binary_type type)
707 if (dso__needs_decompress(dso)) {
708 fd = dso__decompress_kmodule_fd(dso, name);
712 type = dso->symtab_type;
714 fd = open(name, O_RDONLY);
716 dso->load_errno = errno;
721 elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
723 pr_debug("%s: cannot read %s ELF file.\n", __func__, name);
724 dso->load_errno = DSO_LOAD_ERRNO__INVALID_ELF;
728 if (gelf_getehdr(elf, &ehdr) == NULL) {
729 dso->load_errno = DSO_LOAD_ERRNO__INVALID_ELF;
730 pr_debug("%s: cannot get elf header.\n", __func__);
734 if (dso__swap_init(dso, ehdr.e_ident[EI_DATA])) {
735 dso->load_errno = DSO_LOAD_ERRNO__INTERNAL_ERROR;
739 /* Always reject images with a mismatched build-id: */
740 if (dso->has_build_id && !symbol_conf.ignore_vmlinux_buildid) {
741 u8 build_id[BUILD_ID_SIZE];
743 if (elf_read_build_id(elf, build_id, BUILD_ID_SIZE) < 0) {
744 dso->load_errno = DSO_LOAD_ERRNO__CANNOT_READ_BUILDID;
748 if (!dso__build_id_equal(dso, build_id)) {
749 pr_debug("%s: build id mismatch for %s.\n", __func__, name);
750 dso->load_errno = DSO_LOAD_ERRNO__MISMATCHING_BUILDID;
755 ss->is_64_bit = (gelf_getclass(elf) == ELFCLASS64);
757 ss->symtab = elf_section_by_name(elf, &ehdr, &ss->symshdr, ".symtab",
759 if (ss->symshdr.sh_type != SHT_SYMTAB)
763 ss->dynsym = elf_section_by_name(elf, &ehdr, &ss->dynshdr, ".dynsym",
765 if (ss->dynshdr.sh_type != SHT_DYNSYM)
769 ss->opdsec = elf_section_by_name(elf, &ehdr, &ss->opdshdr, ".opd",
771 if (ss->opdshdr.sh_type != SHT_PROGBITS)
774 if (dso->kernel == DSO_TYPE_USER)
775 ss->adjust_symbols = true;
777 ss->adjust_symbols = elf__needs_adjust_symbols(ehdr);
779 ss->name = strdup(name);
781 dso->load_errno = errno;
800 * ref_reloc_sym_not_found - has kernel relocation symbol been found.
801 * @kmap: kernel maps and relocation reference symbol
803 * This function returns %true if we are dealing with the kernel maps and the
804 * relocation reference symbol has not yet been found. Otherwise %false is
807 static bool ref_reloc_sym_not_found(struct kmap *kmap)
809 return kmap && kmap->ref_reloc_sym && kmap->ref_reloc_sym->name &&
810 !kmap->ref_reloc_sym->unrelocated_addr;
814 * ref_reloc - kernel relocation offset.
815 * @kmap: kernel maps and relocation reference symbol
817 * This function returns the offset of kernel addresses as determined by using
818 * the relocation reference symbol i.e. if the kernel has not been relocated
819 * then the return value is zero.
821 static u64 ref_reloc(struct kmap *kmap)
823 if (kmap && kmap->ref_reloc_sym &&
824 kmap->ref_reloc_sym->unrelocated_addr)
825 return kmap->ref_reloc_sym->addr -
826 kmap->ref_reloc_sym->unrelocated_addr;
830 void __weak arch__sym_update(struct symbol *s __maybe_unused,
831 GElf_Sym *sym __maybe_unused) { }
833 static int dso__process_kernel_symbol(struct dso *dso, struct map *map,
834 GElf_Sym *sym, GElf_Shdr *shdr,
835 struct map_groups *kmaps, struct kmap *kmap,
836 struct dso **curr_dsop, struct map **curr_mapp,
837 const char *section_name,
838 bool adjust_kernel_syms, bool kmodule, bool *remap_kernel)
840 struct dso *curr_dso = *curr_dsop;
841 struct map *curr_map;
842 char dso_name[PATH_MAX];
844 /* Adjust symbol to map to file offset */
845 if (adjust_kernel_syms)
846 sym->st_value -= shdr->sh_addr - shdr->sh_offset;
848 if (strcmp(section_name, (curr_dso->short_name + dso->short_name_len)) == 0)
851 if (strcmp(section_name, ".text") == 0) {
853 * The initial kernel mapping is based on
854 * kallsyms and identity maps. Overwrite it to
855 * map to the kernel dso.
857 if (*remap_kernel && dso->kernel) {
858 *remap_kernel = false;
859 map->start = shdr->sh_addr + ref_reloc(kmap);
860 map->end = map->start + shdr->sh_size;
861 map->pgoff = shdr->sh_offset;
862 map->map_ip = map__map_ip;
863 map->unmap_ip = map__unmap_ip;
864 /* Ensure maps are correctly ordered */
867 map_groups__remove(kmaps, map);
868 map_groups__insert(kmaps, map);
874 * The initial module mapping is based on
875 * /proc/modules mapped to offset zero.
876 * Overwrite it to map to the module dso.
878 if (*remap_kernel && kmodule) {
879 *remap_kernel = false;
880 map->pgoff = shdr->sh_offset;
891 snprintf(dso_name, sizeof(dso_name), "%s%s", dso->short_name, section_name);
893 curr_map = map_groups__find_by_name(kmaps, dso_name);
894 if (curr_map == NULL) {
895 u64 start = sym->st_value;
898 start += map->start + shdr->sh_offset;
900 curr_dso = dso__new(dso_name);
901 if (curr_dso == NULL)
903 curr_dso->kernel = dso->kernel;
904 curr_dso->long_name = dso->long_name;
905 curr_dso->long_name_len = dso->long_name_len;
906 curr_map = map__new2(start, curr_dso);
908 if (curr_map == NULL)
911 if (adjust_kernel_syms) {
912 curr_map->start = shdr->sh_addr + ref_reloc(kmap);
913 curr_map->end = curr_map->start + shdr->sh_size;
914 curr_map->pgoff = shdr->sh_offset;
916 curr_map->map_ip = curr_map->unmap_ip = identity__map_ip;
918 curr_dso->symtab_type = dso->symtab_type;
919 map_groups__insert(kmaps, curr_map);
921 * Add it before we drop the referece to curr_map, i.e. while
922 * we still are sure to have a reference to this DSO via
925 dsos__add(&map->groups->machine->dsos, curr_dso);
926 /* kmaps already got it */
928 dso__set_loaded(curr_dso);
929 *curr_mapp = curr_map;
930 *curr_dsop = curr_dso;
932 *curr_dsop = curr_map->dso;
937 int dso__load_sym(struct dso *dso, struct map *map, struct symsrc *syms_ss,
938 struct symsrc *runtime_ss, int kmodule)
940 struct kmap *kmap = dso->kernel ? map__kmap(map) : NULL;
941 struct map_groups *kmaps = kmap ? map__kmaps(map) : NULL;
942 struct map *curr_map = map;
943 struct dso *curr_dso = dso;
944 Elf_Data *symstrs, *secstrs;
951 Elf_Data *syms, *opddata = NULL;
953 Elf_Scn *sec, *sec_strndx;
956 bool remap_kernel = false, adjust_kernel_syms = false;
961 dso->symtab_type = syms_ss->type;
962 dso->is_64_bit = syms_ss->is_64_bit;
963 dso->rel = syms_ss->ehdr.e_type == ET_REL;
966 * Modules may already have symbols from kallsyms, but those symbols
967 * have the wrong values for the dso maps, so remove them.
969 if (kmodule && syms_ss->symtab)
970 symbols__delete(&dso->symbols);
972 if (!syms_ss->symtab) {
974 * If the vmlinux is stripped, fail so we will fall back
975 * to using kallsyms. The vmlinux runtime symbols aren't
981 syms_ss->symtab = syms_ss->dynsym;
982 syms_ss->symshdr = syms_ss->dynshdr;
986 ehdr = syms_ss->ehdr;
987 sec = syms_ss->symtab;
988 shdr = syms_ss->symshdr;
990 if (elf_section_by_name(runtime_ss->elf, &runtime_ss->ehdr, &tshdr,
992 dso->text_offset = tshdr.sh_addr - tshdr.sh_offset;
994 if (runtime_ss->opdsec)
995 opddata = elf_rawdata(runtime_ss->opdsec, NULL);
997 syms = elf_getdata(sec, NULL);
1001 sec = elf_getscn(elf, shdr.sh_link);
1005 symstrs = elf_getdata(sec, NULL);
1006 if (symstrs == NULL)
1009 sec_strndx = elf_getscn(runtime_ss->elf, runtime_ss->ehdr.e_shstrndx);
1010 if (sec_strndx == NULL)
1013 secstrs = elf_getdata(sec_strndx, NULL);
1014 if (secstrs == NULL)
1017 nr_syms = shdr.sh_size / shdr.sh_entsize;
1019 memset(&sym, 0, sizeof(sym));
1022 * The kernel relocation symbol is needed in advance in order to adjust
1023 * kernel maps correctly.
1025 if (ref_reloc_sym_not_found(kmap)) {
1026 elf_symtab__for_each_symbol(syms, nr_syms, idx, sym) {
1027 const char *elf_name = elf_sym__name(&sym, symstrs);
1029 if (strcmp(elf_name, kmap->ref_reloc_sym->name))
1031 kmap->ref_reloc_sym->unrelocated_addr = sym.st_value;
1032 map->reloc = kmap->ref_reloc_sym->addr -
1033 kmap->ref_reloc_sym->unrelocated_addr;
1039 * Handle any relocation of vdso necessary because older kernels
1040 * attempted to prelink vdso to its virtual address.
1042 if (dso__is_vdso(dso))
1043 map->reloc = map->start - dso->text_offset;
1045 dso->adjust_symbols = runtime_ss->adjust_symbols || ref_reloc(kmap);
1047 * Initial kernel and module mappings do not map to the dso.
1050 if (dso->kernel || kmodule) {
1051 remap_kernel = true;
1052 adjust_kernel_syms = dso->adjust_symbols;
1054 elf_symtab__for_each_symbol(syms, nr_syms, idx, sym) {
1056 const char *elf_name = elf_sym__name(&sym, symstrs);
1057 char *demangled = NULL;
1058 int is_label = elf_sym__is_label(&sym);
1059 const char *section_name;
1060 bool used_opd = false;
1062 if (!is_label && !elf_sym__filter(&sym))
1065 /* Reject ARM ELF "mapping symbols": these aren't unique and
1066 * don't identify functions, so will confuse the profile
1068 if (ehdr.e_machine == EM_ARM || ehdr.e_machine == EM_AARCH64) {
1069 if (elf_name[0] == '$' && strchr("adtx", elf_name[1])
1070 && (elf_name[2] == '\0' || elf_name[2] == '.'))
1074 if (runtime_ss->opdsec && sym.st_shndx == runtime_ss->opdidx) {
1075 u32 offset = sym.st_value - syms_ss->opdshdr.sh_addr;
1076 u64 *opd = opddata->d_buf + offset;
1077 sym.st_value = DSO__SWAP(dso, u64, *opd);
1078 sym.st_shndx = elf_addr_to_index(runtime_ss->elf,
1083 * When loading symbols in a data mapping, ABS symbols (which
1084 * has a value of SHN_ABS in its st_shndx) failed at
1085 * elf_getscn(). And it marks the loading as a failure so
1086 * already loaded symbols cannot be fixed up.
1088 * I'm not sure what should be done. Just ignore them for now.
1091 if (sym.st_shndx == SHN_ABS)
1094 sec = elf_getscn(runtime_ss->elf, sym.st_shndx);
1098 gelf_getshdr(sec, &shdr);
1100 if (is_label && !elf_sec__filter(&shdr, secstrs))
1103 section_name = elf_sec__name(&shdr, secstrs);
1105 /* On ARM, symbols for thumb functions have 1 added to
1106 * the symbol address as a flag - remove it */
1107 if ((ehdr.e_machine == EM_ARM) &&
1108 (GELF_ST_TYPE(sym.st_info) == STT_FUNC) &&
1112 if (dso->kernel || kmodule) {
1113 if (dso__process_kernel_symbol(dso, map, &sym, &shdr, kmaps, kmap, &curr_dso, &curr_map,
1114 section_name, adjust_kernel_syms, kmodule, &remap_kernel))
1116 } else if ((used_opd && runtime_ss->adjust_symbols) ||
1117 (!used_opd && syms_ss->adjust_symbols)) {
1118 pr_debug4("%s: adjusting symbol: st_value: %#" PRIx64 " "
1119 "sh_addr: %#" PRIx64 " sh_offset: %#" PRIx64 "\n", __func__,
1120 (u64)sym.st_value, (u64)shdr.sh_addr,
1121 (u64)shdr.sh_offset);
1122 sym.st_value -= shdr.sh_addr - shdr.sh_offset;
1125 demangled = demangle_sym(dso, kmodule, elf_name);
1126 if (demangled != NULL)
1127 elf_name = demangled;
1129 f = symbol__new(sym.st_value, sym.st_size,
1130 GELF_ST_BIND(sym.st_info),
1131 GELF_ST_TYPE(sym.st_info), elf_name);
1136 arch__sym_update(f, &sym);
1138 __symbols__insert(&curr_dso->symbols, f, dso->kernel);
1143 * For misannotated, zeroed, ASM function sizes.
1146 symbols__fixup_end(&dso->symbols);
1147 symbols__fixup_duplicate(&dso->symbols);
1150 * We need to fixup this here too because we create new
1151 * maps here, for things like vsyscall sections.
1153 map_groups__fixup_end(kmaps);
1161 static int elf_read_maps(Elf *elf, bool exe, mapfn_t mapfn, void *data)
1168 if (elf_getphdrnum(elf, &phdrnum))
1171 for (i = 0; i < phdrnum; i++) {
1172 if (gelf_getphdr(elf, i, &phdr) == NULL)
1174 if (phdr.p_type != PT_LOAD)
1177 if (!(phdr.p_flags & PF_X))
1180 if (!(phdr.p_flags & PF_R))
1183 sz = min(phdr.p_memsz, phdr.p_filesz);
1186 err = mapfn(phdr.p_vaddr, sz, phdr.p_offset, data);
1193 int file__read_maps(int fd, bool exe, mapfn_t mapfn, void *data,
1199 elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
1204 *is_64_bit = (gelf_getclass(elf) == ELFCLASS64);
1206 err = elf_read_maps(elf, exe, mapfn, data);
1212 enum dso_type dso__type_fd(int fd)
1214 enum dso_type dso_type = DSO__TYPE_UNKNOWN;
1219 elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
1224 if (ek != ELF_K_ELF)
1227 if (gelf_getclass(elf) == ELFCLASS64) {
1228 dso_type = DSO__TYPE_64BIT;
1232 if (gelf_getehdr(elf, &ehdr) == NULL)
1235 if (ehdr.e_machine == EM_X86_64)
1236 dso_type = DSO__TYPE_X32BIT;
1238 dso_type = DSO__TYPE_32BIT;
1245 static int copy_bytes(int from, off_t from_offs, int to, off_t to_offs, u64 len)
1250 char *buf = malloc(page_size);
1255 if (lseek(to, to_offs, SEEK_SET) != to_offs)
1258 if (lseek(from, from_offs, SEEK_SET) != from_offs)
1265 /* Use read because mmap won't work on proc files */
1266 r = read(from, buf, n);
1272 r = write(to, buf, n);
1293 static int kcore__open(struct kcore *kcore, const char *filename)
1297 kcore->fd = open(filename, O_RDONLY);
1298 if (kcore->fd == -1)
1301 kcore->elf = elf_begin(kcore->fd, ELF_C_READ, NULL);
1305 kcore->elfclass = gelf_getclass(kcore->elf);
1306 if (kcore->elfclass == ELFCLASSNONE)
1309 ehdr = gelf_getehdr(kcore->elf, &kcore->ehdr);
1316 elf_end(kcore->elf);
1322 static int kcore__init(struct kcore *kcore, char *filename, int elfclass,
1325 kcore->elfclass = elfclass;
1328 kcore->fd = mkstemp(filename);
1330 kcore->fd = open(filename, O_WRONLY | O_CREAT | O_EXCL, 0400);
1331 if (kcore->fd == -1)
1334 kcore->elf = elf_begin(kcore->fd, ELF_C_WRITE, NULL);
1338 if (!gelf_newehdr(kcore->elf, elfclass))
1341 memset(&kcore->ehdr, 0, sizeof(GElf_Ehdr));
1346 elf_end(kcore->elf);
1353 static void kcore__close(struct kcore *kcore)
1355 elf_end(kcore->elf);
1359 static int kcore__copy_hdr(struct kcore *from, struct kcore *to, size_t count)
1361 GElf_Ehdr *ehdr = &to->ehdr;
1362 GElf_Ehdr *kehdr = &from->ehdr;
1364 memcpy(ehdr->e_ident, kehdr->e_ident, EI_NIDENT);
1365 ehdr->e_type = kehdr->e_type;
1366 ehdr->e_machine = kehdr->e_machine;
1367 ehdr->e_version = kehdr->e_version;
1370 ehdr->e_flags = kehdr->e_flags;
1371 ehdr->e_phnum = count;
1372 ehdr->e_shentsize = 0;
1374 ehdr->e_shstrndx = 0;
1376 if (from->elfclass == ELFCLASS32) {
1377 ehdr->e_phoff = sizeof(Elf32_Ehdr);
1378 ehdr->e_ehsize = sizeof(Elf32_Ehdr);
1379 ehdr->e_phentsize = sizeof(Elf32_Phdr);
1381 ehdr->e_phoff = sizeof(Elf64_Ehdr);
1382 ehdr->e_ehsize = sizeof(Elf64_Ehdr);
1383 ehdr->e_phentsize = sizeof(Elf64_Phdr);
1386 if (!gelf_update_ehdr(to->elf, ehdr))
1389 if (!gelf_newphdr(to->elf, count))
1395 static int kcore__add_phdr(struct kcore *kcore, int idx, off_t offset,
1400 .p_flags = PF_R | PF_W | PF_X,
1406 .p_align = page_size,
1409 if (!gelf_update_phdr(kcore->elf, idx, &phdr))
1415 static off_t kcore__write(struct kcore *kcore)
1417 return elf_update(kcore->elf, ELF_C_WRITE);
1425 struct list_head node;
1426 struct phdr_data *remaps;
1431 struct list_head node;
1434 struct kcore_copy_info {
1440 u64 last_module_symbol;
1442 struct list_head phdrs;
1443 struct list_head syms;
1446 #define kcore_copy__for_each_phdr(k, p) \
1447 list_for_each_entry((p), &(k)->phdrs, node)
1449 static struct phdr_data *phdr_data__new(u64 addr, u64 len, off_t offset)
1451 struct phdr_data *p = zalloc(sizeof(*p));
1462 static struct phdr_data *kcore_copy_info__addnew(struct kcore_copy_info *kci,
1466 struct phdr_data *p = phdr_data__new(addr, len, offset);
1469 list_add_tail(&p->node, &kci->phdrs);
1474 static void kcore_copy__free_phdrs(struct kcore_copy_info *kci)
1476 struct phdr_data *p, *tmp;
1478 list_for_each_entry_safe(p, tmp, &kci->phdrs, node) {
1484 static struct sym_data *kcore_copy__new_sym(struct kcore_copy_info *kci,
1487 struct sym_data *s = zalloc(sizeof(*s));
1491 list_add_tail(&s->node, &kci->syms);
1497 static void kcore_copy__free_syms(struct kcore_copy_info *kci)
1499 struct sym_data *s, *tmp;
1501 list_for_each_entry_safe(s, tmp, &kci->syms, node) {
1507 static int kcore_copy__process_kallsyms(void *arg, const char *name, char type,
1510 struct kcore_copy_info *kci = arg;
1512 if (!kallsyms__is_function(type))
1515 if (strchr(name, '[')) {
1516 if (start > kci->last_module_symbol)
1517 kci->last_module_symbol = start;
1521 if (!kci->first_symbol || start < kci->first_symbol)
1522 kci->first_symbol = start;
1524 if (!kci->last_symbol || start > kci->last_symbol)
1525 kci->last_symbol = start;
1527 if (!strcmp(name, "_stext")) {
1532 if (!strcmp(name, "_etext")) {
1537 if (is_entry_trampoline(name) && !kcore_copy__new_sym(kci, start))
1543 static int kcore_copy__parse_kallsyms(struct kcore_copy_info *kci,
1546 char kallsyms_filename[PATH_MAX];
1548 scnprintf(kallsyms_filename, PATH_MAX, "%s/kallsyms", dir);
1550 if (symbol__restricted_filename(kallsyms_filename, "/proc/kallsyms"))
1553 if (kallsyms__parse(kallsyms_filename, kci,
1554 kcore_copy__process_kallsyms) < 0)
1560 static int kcore_copy__process_modules(void *arg,
1561 const char *name __maybe_unused,
1562 u64 start, u64 size __maybe_unused)
1564 struct kcore_copy_info *kci = arg;
1566 if (!kci->first_module || start < kci->first_module)
1567 kci->first_module = start;
1572 static int kcore_copy__parse_modules(struct kcore_copy_info *kci,
1575 char modules_filename[PATH_MAX];
1577 scnprintf(modules_filename, PATH_MAX, "%s/modules", dir);
1579 if (symbol__restricted_filename(modules_filename, "/proc/modules"))
1582 if (modules__parse(modules_filename, kci,
1583 kcore_copy__process_modules) < 0)
1589 static int kcore_copy__map(struct kcore_copy_info *kci, u64 start, u64 end,
1590 u64 pgoff, u64 s, u64 e)
1594 if (s < start || s >= end)
1597 offset = (s - start) + pgoff;
1598 len = e < end ? e - s : end - s;
1600 return kcore_copy_info__addnew(kci, s, len, offset) ? 0 : -1;
1603 static int kcore_copy__read_map(u64 start, u64 len, u64 pgoff, void *data)
1605 struct kcore_copy_info *kci = data;
1606 u64 end = start + len;
1607 struct sym_data *sdat;
1609 if (kcore_copy__map(kci, start, end, pgoff, kci->stext, kci->etext))
1612 if (kcore_copy__map(kci, start, end, pgoff, kci->first_module,
1613 kci->last_module_symbol))
1616 list_for_each_entry(sdat, &kci->syms, node) {
1617 u64 s = round_down(sdat->addr, page_size);
1619 if (kcore_copy__map(kci, start, end, pgoff, s, s + len))
1626 static int kcore_copy__read_maps(struct kcore_copy_info *kci, Elf *elf)
1628 if (elf_read_maps(elf, true, kcore_copy__read_map, kci) < 0)
1634 static void kcore_copy__find_remaps(struct kcore_copy_info *kci)
1636 struct phdr_data *p, *k = NULL;
1642 /* Find phdr that corresponds to the kernel map (contains stext) */
1643 kcore_copy__for_each_phdr(kci, p) {
1644 u64 pend = p->addr + p->len - 1;
1646 if (p->addr <= kci->stext && pend >= kci->stext) {
1655 kend = k->offset + k->len;
1657 /* Find phdrs that remap the kernel */
1658 kcore_copy__for_each_phdr(kci, p) {
1659 u64 pend = p->offset + p->len;
1664 if (p->offset >= k->offset && pend <= kend)
1669 static void kcore_copy__layout(struct kcore_copy_info *kci)
1671 struct phdr_data *p;
1674 kcore_copy__find_remaps(kci);
1676 kcore_copy__for_each_phdr(kci, p) {
1684 kcore_copy__for_each_phdr(kci, p) {
1685 struct phdr_data *k = p->remaps;
1688 p->rel = p->offset - k->offset + k->rel;
1692 static int kcore_copy__calc_maps(struct kcore_copy_info *kci, const char *dir,
1695 if (kcore_copy__parse_kallsyms(kci, dir))
1698 if (kcore_copy__parse_modules(kci, dir))
1702 kci->stext = round_down(kci->stext, page_size);
1704 kci->stext = round_down(kci->first_symbol, page_size);
1707 kci->etext = round_up(kci->etext, page_size);
1708 } else if (kci->last_symbol) {
1709 kci->etext = round_up(kci->last_symbol, page_size);
1710 kci->etext += page_size;
1713 kci->first_module = round_down(kci->first_module, page_size);
1715 if (kci->last_module_symbol) {
1716 kci->last_module_symbol = round_up(kci->last_module_symbol,
1718 kci->last_module_symbol += page_size;
1721 if (!kci->stext || !kci->etext)
1724 if (kci->first_module && !kci->last_module_symbol)
1727 if (kcore_copy__read_maps(kci, elf))
1730 kcore_copy__layout(kci);
1735 static int kcore_copy__copy_file(const char *from_dir, const char *to_dir,
1738 char from_filename[PATH_MAX];
1739 char to_filename[PATH_MAX];
1741 scnprintf(from_filename, PATH_MAX, "%s/%s", from_dir, name);
1742 scnprintf(to_filename, PATH_MAX, "%s/%s", to_dir, name);
1744 return copyfile_mode(from_filename, to_filename, 0400);
1747 static int kcore_copy__unlink(const char *dir, const char *name)
1749 char filename[PATH_MAX];
1751 scnprintf(filename, PATH_MAX, "%s/%s", dir, name);
1753 return unlink(filename);
1756 static int kcore_copy__compare_fds(int from, int to)
1764 buf_from = malloc(page_size);
1765 buf_to = malloc(page_size);
1766 if (!buf_from || !buf_to)
1770 /* Use read because mmap won't work on proc files */
1771 ret = read(from, buf_from, page_size);
1780 if (readn(to, buf_to, len) != (int)len)
1783 if (memcmp(buf_from, buf_to, len))
1794 static int kcore_copy__compare_files(const char *from_filename,
1795 const char *to_filename)
1797 int from, to, err = -1;
1799 from = open(from_filename, O_RDONLY);
1803 to = open(to_filename, O_RDONLY);
1805 goto out_close_from;
1807 err = kcore_copy__compare_fds(from, to);
1815 static int kcore_copy__compare_file(const char *from_dir, const char *to_dir,
1818 char from_filename[PATH_MAX];
1819 char to_filename[PATH_MAX];
1821 scnprintf(from_filename, PATH_MAX, "%s/%s", from_dir, name);
1822 scnprintf(to_filename, PATH_MAX, "%s/%s", to_dir, name);
1824 return kcore_copy__compare_files(from_filename, to_filename);
1828 * kcore_copy - copy kallsyms, modules and kcore from one directory to another.
1829 * @from_dir: from directory
1830 * @to_dir: to directory
1832 * This function copies kallsyms, modules and kcore files from one directory to
1833 * another. kallsyms and modules are copied entirely. Only code segments are
1834 * copied from kcore. It is assumed that two segments suffice: one for the
1835 * kernel proper and one for all the modules. The code segments are determined
1836 * from kallsyms and modules files. The kernel map starts at _stext or the
1837 * lowest function symbol, and ends at _etext or the highest function symbol.
1838 * The module map starts at the lowest module address and ends at the highest
1839 * module symbol. Start addresses are rounded down to the nearest page. End
1840 * addresses are rounded up to the nearest page. An extra page is added to the
1841 * highest kernel symbol and highest module symbol to, hopefully, encompass that
1842 * symbol too. Because it contains only code sections, the resulting kcore is
1843 * unusual. One significant peculiarity is that the mapping (start -> pgoff)
1844 * is not the same for the kernel map and the modules map. That happens because
1845 * the data is copied adjacently whereas the original kcore has gaps. Finally,
1846 * kallsyms and modules files are compared with their copies to check that
1847 * modules have not been loaded or unloaded while the copies were taking place.
1849 * Return: %0 on success, %-1 on failure.
1851 int kcore_copy(const char *from_dir, const char *to_dir)
1854 struct kcore extract;
1855 int idx = 0, err = -1;
1857 struct kcore_copy_info kci = { .stext = 0, };
1858 char kcore_filename[PATH_MAX];
1859 char extract_filename[PATH_MAX];
1860 struct phdr_data *p;
1862 INIT_LIST_HEAD(&kci.phdrs);
1863 INIT_LIST_HEAD(&kci.syms);
1865 if (kcore_copy__copy_file(from_dir, to_dir, "kallsyms"))
1868 if (kcore_copy__copy_file(from_dir, to_dir, "modules"))
1869 goto out_unlink_kallsyms;
1871 scnprintf(kcore_filename, PATH_MAX, "%s/kcore", from_dir);
1872 scnprintf(extract_filename, PATH_MAX, "%s/kcore", to_dir);
1874 if (kcore__open(&kcore, kcore_filename))
1875 goto out_unlink_modules;
1877 if (kcore_copy__calc_maps(&kci, from_dir, kcore.elf))
1878 goto out_kcore_close;
1880 if (kcore__init(&extract, extract_filename, kcore.elfclass, false))
1881 goto out_kcore_close;
1883 if (kcore__copy_hdr(&kcore, &extract, kci.phnum))
1884 goto out_extract_close;
1886 offset = gelf_fsize(extract.elf, ELF_T_EHDR, 1, EV_CURRENT) +
1887 gelf_fsize(extract.elf, ELF_T_PHDR, kci.phnum, EV_CURRENT);
1888 offset = round_up(offset, page_size);
1890 kcore_copy__for_each_phdr(&kci, p) {
1891 off_t offs = p->rel + offset;
1893 if (kcore__add_phdr(&extract, idx++, offs, p->addr, p->len))
1894 goto out_extract_close;
1897 sz = kcore__write(&extract);
1898 if (sz < 0 || sz > offset)
1899 goto out_extract_close;
1901 kcore_copy__for_each_phdr(&kci, p) {
1902 off_t offs = p->rel + offset;
1906 if (copy_bytes(kcore.fd, p->offset, extract.fd, offs, p->len))
1907 goto out_extract_close;
1910 if (kcore_copy__compare_file(from_dir, to_dir, "modules"))
1911 goto out_extract_close;
1913 if (kcore_copy__compare_file(from_dir, to_dir, "kallsyms"))
1914 goto out_extract_close;
1919 kcore__close(&extract);
1921 unlink(extract_filename);
1923 kcore__close(&kcore);
1926 kcore_copy__unlink(to_dir, "modules");
1927 out_unlink_kallsyms:
1929 kcore_copy__unlink(to_dir, "kallsyms");
1931 kcore_copy__free_phdrs(&kci);
1932 kcore_copy__free_syms(&kci);
1937 int kcore_extract__create(struct kcore_extract *kce)
1940 struct kcore extract;
1942 int idx = 0, err = -1;
1943 off_t offset = page_size, sz;
1945 if (kcore__open(&kcore, kce->kcore_filename))
1948 strcpy(kce->extract_filename, PERF_KCORE_EXTRACT);
1949 if (kcore__init(&extract, kce->extract_filename, kcore.elfclass, true))
1950 goto out_kcore_close;
1952 if (kcore__copy_hdr(&kcore, &extract, count))
1953 goto out_extract_close;
1955 if (kcore__add_phdr(&extract, idx, offset, kce->addr, kce->len))
1956 goto out_extract_close;
1958 sz = kcore__write(&extract);
1959 if (sz < 0 || sz > offset)
1960 goto out_extract_close;
1962 if (copy_bytes(kcore.fd, kce->offs, extract.fd, offset, kce->len))
1963 goto out_extract_close;
1968 kcore__close(&extract);
1970 unlink(kce->extract_filename);
1972 kcore__close(&kcore);
1977 void kcore_extract__delete(struct kcore_extract *kce)
1979 unlink(kce->extract_filename);
1982 #ifdef HAVE_GELF_GETNOTE_SUPPORT
1984 static void sdt_adjust_loc(struct sdt_note *tmp, GElf_Addr base_off)
1990 tmp->addr.a32[SDT_NOTE_IDX_LOC] =
1991 tmp->addr.a32[SDT_NOTE_IDX_LOC] + base_off -
1992 tmp->addr.a32[SDT_NOTE_IDX_BASE];
1994 tmp->addr.a64[SDT_NOTE_IDX_LOC] =
1995 tmp->addr.a64[SDT_NOTE_IDX_LOC] + base_off -
1996 tmp->addr.a64[SDT_NOTE_IDX_BASE];
1999 static void sdt_adjust_refctr(struct sdt_note *tmp, GElf_Addr base_addr,
2005 if (tmp->bit32 && tmp->addr.a32[SDT_NOTE_IDX_REFCTR])
2006 tmp->addr.a32[SDT_NOTE_IDX_REFCTR] -= (base_addr - base_off);
2007 else if (tmp->addr.a64[SDT_NOTE_IDX_REFCTR])
2008 tmp->addr.a64[SDT_NOTE_IDX_REFCTR] -= (base_addr - base_off);
2012 * populate_sdt_note : Parse raw data and identify SDT note
2013 * @elf: elf of the opened file
2014 * @data: raw data of a section with description offset applied
2015 * @len: note description size
2016 * @type: type of the note
2017 * @sdt_notes: List to add the SDT note
2019 * Responsible for parsing the @data in section .note.stapsdt in @elf and
2020 * if its an SDT note, it appends to @sdt_notes list.
2022 static int populate_sdt_note(Elf **elf, const char *data, size_t len,
2023 struct list_head *sdt_notes)
2025 const char *provider, *name, *args;
2026 struct sdt_note *tmp = NULL;
2032 Elf64_Addr a64[NR_ADDR];
2033 Elf32_Addr a32[NR_ADDR];
2037 .d_buf = &buf, .d_type = ELF_T_ADDR, .d_version = EV_CURRENT,
2038 .d_size = gelf_fsize((*elf), ELF_T_ADDR, NR_ADDR, EV_CURRENT),
2039 .d_off = 0, .d_align = 0
2042 .d_buf = (void *) data, .d_type = ELF_T_ADDR,
2043 .d_version = EV_CURRENT, .d_size = dst.d_size, .d_off = 0,
2047 tmp = (struct sdt_note *)calloc(1, sizeof(struct sdt_note));
2053 INIT_LIST_HEAD(&tmp->note_list);
2055 if (len < dst.d_size + 3)
2058 /* Translation from file representation to memory representation */
2059 if (gelf_xlatetom(*elf, &dst, &src,
2060 elf_getident(*elf, NULL)[EI_DATA]) == NULL) {
2061 pr_err("gelf_xlatetom : %s\n", elf_errmsg(-1));
2065 /* Populate the fields of sdt_note */
2066 provider = data + dst.d_size;
2068 name = (const char *)memchr(provider, '\0', data + len - provider);
2072 tmp->provider = strdup(provider);
2073 if (!tmp->provider) {
2077 tmp->name = strdup(name);
2083 args = memchr(name, '\0', data + len - name);
2086 * There is no argument if:
2087 * - We reached the end of the note;
2088 * - There is not enough room to hold a potential string;
2089 * - The argument string is empty or just contains ':'.
2091 if (args == NULL || data + len - args < 2 ||
2092 args[1] == ':' || args[1] == '\0')
2095 tmp->args = strdup(++args);
2102 if (gelf_getclass(*elf) == ELFCLASS32) {
2103 memcpy(&tmp->addr, &buf, 3 * sizeof(Elf32_Addr));
2106 memcpy(&tmp->addr, &buf, 3 * sizeof(Elf64_Addr));
2110 if (!gelf_getehdr(*elf, &ehdr)) {
2111 pr_debug("%s : cannot get elf header.\n", __func__);
2116 /* Adjust the prelink effect :
2117 * Find out the .stapsdt.base section.
2118 * This scn will help us to handle prelinking (if present).
2119 * Compare the retrieved file offset of the base section with the
2120 * base address in the description of the SDT note. If its different,
2121 * then accordingly, adjust the note location.
2123 if (elf_section_by_name(*elf, &ehdr, &shdr, SDT_BASE_SCN, NULL))
2124 sdt_adjust_loc(tmp, shdr.sh_offset);
2126 /* Adjust reference counter offset */
2127 if (elf_section_by_name(*elf, &ehdr, &shdr, SDT_PROBES_SCN, NULL))
2128 sdt_adjust_refctr(tmp, shdr.sh_addr, shdr.sh_offset);
2130 list_add_tail(&tmp->note_list, sdt_notes);
2138 free(tmp->provider);
2146 * construct_sdt_notes_list : constructs a list of SDT notes
2147 * @elf : elf to look into
2148 * @sdt_notes : empty list_head
2150 * Scans the sections in 'elf' for the section
2151 * .note.stapsdt. It, then calls populate_sdt_note to find
2152 * out the SDT events and populates the 'sdt_notes'.
2154 static int construct_sdt_notes_list(Elf *elf, struct list_head *sdt_notes)
2157 Elf_Scn *scn = NULL;
2160 size_t shstrndx, next;
2162 size_t name_off, desc_off, offset;
2165 if (gelf_getehdr(elf, &ehdr) == NULL) {
2169 if (elf_getshdrstrndx(elf, &shstrndx) != 0) {
2174 /* Look for the required section */
2175 scn = elf_section_by_name(elf, &ehdr, &shdr, SDT_NOTE_SCN, NULL);
2181 if ((shdr.sh_type != SHT_NOTE) || (shdr.sh_flags & SHF_ALLOC)) {
2186 data = elf_getdata(scn, NULL);
2188 /* Get the SDT notes */
2189 for (offset = 0; (next = gelf_getnote(data, offset, &nhdr, &name_off,
2190 &desc_off)) > 0; offset = next) {
2191 if (nhdr.n_namesz == sizeof(SDT_NOTE_NAME) &&
2192 !memcmp(data->d_buf + name_off, SDT_NOTE_NAME,
2193 sizeof(SDT_NOTE_NAME))) {
2194 /* Check the type of the note */
2195 if (nhdr.n_type != SDT_NOTE_TYPE)
2198 ret = populate_sdt_note(&elf, ((data->d_buf) + desc_off),
2199 nhdr.n_descsz, sdt_notes);
2204 if (list_empty(sdt_notes))
2212 * get_sdt_note_list : Wrapper to construct a list of sdt notes
2213 * @head : empty list_head
2214 * @target : file to find SDT notes from
2216 * This opens the file, initializes
2217 * the ELF and then calls construct_sdt_notes_list.
2219 int get_sdt_note_list(struct list_head *head, const char *target)
2224 fd = open(target, O_RDONLY);
2228 elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
2233 ret = construct_sdt_notes_list(elf, head);
2241 * cleanup_sdt_note_list : free the sdt notes' list
2242 * @sdt_notes: sdt notes' list
2244 * Free up the SDT notes in @sdt_notes.
2245 * Returns the number of SDT notes free'd.
2247 int cleanup_sdt_note_list(struct list_head *sdt_notes)
2249 struct sdt_note *tmp, *pos;
2252 list_for_each_entry_safe(pos, tmp, sdt_notes, note_list) {
2253 list_del(&pos->note_list);
2255 free(pos->provider);
2263 * sdt_notes__get_count: Counts the number of sdt events
2264 * @start: list_head to sdt_notes list
2266 * Returns the number of SDT notes in a list
2268 int sdt_notes__get_count(struct list_head *start)
2270 struct sdt_note *sdt_ptr;
2273 list_for_each_entry(sdt_ptr, start, note_list)
2279 void symbol__elf_init(void)
2281 elf_version(EV_CURRENT);