1 // SPDX-License-Identifier: GPL-2.0
15 #include "demangle-ocaml.h"
16 #include "demangle-java.h"
17 #include "demangle-rust.h"
21 #include "util/copyfile.h"
22 #include <linux/ctype.h>
23 #include <linux/kernel.h>
24 #include <linux/zalloc.h>
25 #include <symbol/kallsyms.h>
26 #include <internal/lib.h>
29 #define EM_AARCH64 183 /* ARM 64 bit */
32 #ifndef ELF32_ST_VISIBILITY
33 #define ELF32_ST_VISIBILITY(o) ((o) & 0x03)
36 /* For ELF64 the definitions are the same. */
37 #ifndef ELF64_ST_VISIBILITY
38 #define ELF64_ST_VISIBILITY(o) ELF32_ST_VISIBILITY (o)
41 /* How to extract information held in the st_other field. */
42 #ifndef GELF_ST_VISIBILITY
43 #define GELF_ST_VISIBILITY(val) ELF64_ST_VISIBILITY (val)
46 typedef Elf64_Nhdr GElf_Nhdr;
49 #define DMGL_NO_OPTS 0 /* For readability... */
50 #define DMGL_PARAMS (1 << 0) /* Include function args */
51 #define DMGL_ANSI (1 << 1) /* Include const, volatile, etc */
54 #ifdef HAVE_LIBBFD_SUPPORT
55 #define PACKAGE 'perf'
58 #ifdef HAVE_CPLUS_DEMANGLE_SUPPORT
59 extern char *cplus_demangle(const char *, int);
61 static inline char *bfd_demangle(void __maybe_unused *v, const char *c, int i)
63 return cplus_demangle(c, i);
67 static inline char *bfd_demangle(void __maybe_unused *v,
68 const char __maybe_unused *c,
77 #ifndef HAVE_ELF_GETPHDRNUM_SUPPORT
78 static int elf_getphdrnum(Elf *elf, size_t *dst)
83 ehdr = gelf_getehdr(elf, &gehdr);
93 #ifndef HAVE_ELF_GETSHDRSTRNDX_SUPPORT
94 static int elf_getshdrstrndx(Elf *elf __maybe_unused, size_t *dst __maybe_unused)
96 pr_err("%s: update your libelf to > 0.140, this one lacks elf_getshdrstrndx().\n", __func__);
101 #ifndef NT_GNU_BUILD_ID
102 #define NT_GNU_BUILD_ID 3
106 * elf_symtab__for_each_symbol - iterate thru all the symbols
108 * @syms: struct elf_symtab instance to iterate
110 * @sym: GElf_Sym iterator
112 #define elf_symtab__for_each_symbol(syms, nr_syms, idx, sym) \
113 for (idx = 0, gelf_getsym(syms, idx, &sym);\
115 idx++, gelf_getsym(syms, idx, &sym))
117 static inline uint8_t elf_sym__type(const GElf_Sym *sym)
119 return GELF_ST_TYPE(sym->st_info);
122 static inline uint8_t elf_sym__visibility(const GElf_Sym *sym)
124 return GELF_ST_VISIBILITY(sym->st_other);
127 #ifndef STT_GNU_IFUNC
128 #define STT_GNU_IFUNC 10
131 static inline int elf_sym__is_function(const GElf_Sym *sym)
133 return (elf_sym__type(sym) == STT_FUNC ||
134 elf_sym__type(sym) == STT_GNU_IFUNC) &&
136 sym->st_shndx != SHN_UNDEF;
139 static inline bool elf_sym__is_object(const GElf_Sym *sym)
141 return elf_sym__type(sym) == STT_OBJECT &&
143 sym->st_shndx != SHN_UNDEF;
146 static inline int elf_sym__is_label(const GElf_Sym *sym)
148 return elf_sym__type(sym) == STT_NOTYPE &&
150 sym->st_shndx != SHN_UNDEF &&
151 sym->st_shndx != SHN_ABS &&
152 elf_sym__visibility(sym) != STV_HIDDEN &&
153 elf_sym__visibility(sym) != STV_INTERNAL;
156 static bool elf_sym__filter(GElf_Sym *sym)
158 return elf_sym__is_function(sym) || elf_sym__is_object(sym);
161 static inline const char *elf_sym__name(const GElf_Sym *sym,
162 const Elf_Data *symstrs)
164 return symstrs->d_buf + sym->st_name;
167 static inline const char *elf_sec__name(const GElf_Shdr *shdr,
168 const Elf_Data *secstrs)
170 return secstrs->d_buf + shdr->sh_name;
173 static inline int elf_sec__is_text(const GElf_Shdr *shdr,
174 const Elf_Data *secstrs)
176 return strstr(elf_sec__name(shdr, secstrs), "text") != NULL;
179 static inline bool elf_sec__is_data(const GElf_Shdr *shdr,
180 const Elf_Data *secstrs)
182 return strstr(elf_sec__name(shdr, secstrs), "data") != NULL;
185 static bool elf_sec__filter(GElf_Shdr *shdr, Elf_Data *secstrs)
187 return elf_sec__is_text(shdr, secstrs) ||
188 elf_sec__is_data(shdr, secstrs);
191 static size_t elf_addr_to_index(Elf *elf, GElf_Addr addr)
197 while ((sec = elf_nextscn(elf, sec)) != NULL) {
198 gelf_getshdr(sec, &shdr);
200 if ((addr >= shdr.sh_addr) &&
201 (addr < (shdr.sh_addr + shdr.sh_size)))
210 Elf_Scn *elf_section_by_name(Elf *elf, GElf_Ehdr *ep,
211 GElf_Shdr *shp, const char *name, size_t *idx)
216 /* Elf is corrupted/truncated, avoid calling elf_strptr. */
217 if (!elf_rawdata(elf_getscn(elf, ep->e_shstrndx), NULL))
220 while ((sec = elf_nextscn(elf, sec)) != NULL) {
223 gelf_getshdr(sec, shp);
224 str = elf_strptr(elf, ep->e_shstrndx, shp->sh_name);
225 if (str && !strcmp(name, str)) {
236 static bool want_demangle(bool is_kernel_sym)
238 return is_kernel_sym ? symbol_conf.demangle_kernel : symbol_conf.demangle;
241 static char *demangle_sym(struct dso *dso, int kmodule, const char *elf_name)
243 int demangle_flags = verbose > 0 ? (DMGL_PARAMS | DMGL_ANSI) : DMGL_NO_OPTS;
244 char *demangled = NULL;
247 * We need to figure out if the object was created from C++ sources
248 * DWARF DW_compile_unit has this, but we don't always have access
251 if (!want_demangle(dso->kernel || kmodule))
254 demangled = bfd_demangle(NULL, elf_name, demangle_flags);
255 if (demangled == NULL) {
256 demangled = ocaml_demangle_sym(elf_name);
257 if (demangled == NULL) {
258 demangled = java_demangle_sym(elf_name, JAVA_DEMANGLE_NORET);
261 else if (rust_is_mangled(demangled))
263 * Input to Rust demangling is the BFD-demangled
264 * name which it Rust-demangles in place.
266 rust_demangle_sym(demangled);
271 #define elf_section__for_each_rel(reldata, pos, pos_mem, idx, nr_entries) \
272 for (idx = 0, pos = gelf_getrel(reldata, 0, &pos_mem); \
274 ++idx, pos = gelf_getrel(reldata, idx, &pos_mem))
276 #define elf_section__for_each_rela(reldata, pos, pos_mem, idx, nr_entries) \
277 for (idx = 0, pos = gelf_getrela(reldata, 0, &pos_mem); \
279 ++idx, pos = gelf_getrela(reldata, idx, &pos_mem))
282 * We need to check if we have a .dynsym, so that we can handle the
283 * .plt, synthesizing its symbols, that aren't on the symtabs (be it
284 * .dynsym or .symtab).
285 * And always look at the original dso, not at debuginfo packages, that
286 * have the PLT data stripped out (shdr_rel_plt.sh_type == SHT_NOBITS).
288 int dso__synthesize_plt_symbols(struct dso *dso, struct symsrc *ss)
290 uint32_t nr_rel_entries, idx;
292 u64 plt_offset, plt_header_size, plt_entry_size;
295 GElf_Shdr shdr_rel_plt, shdr_dynsym;
296 Elf_Data *reldata, *syms, *symstrs;
297 Elf_Scn *scn_plt_rel, *scn_symstrs, *scn_dynsym;
300 char sympltname[1024];
302 int nr = 0, symidx, err = 0;
310 scn_dynsym = ss->dynsym;
311 shdr_dynsym = ss->dynshdr;
312 dynsym_idx = ss->dynsym_idx;
314 if (scn_dynsym == NULL)
317 scn_plt_rel = elf_section_by_name(elf, &ehdr, &shdr_rel_plt,
319 if (scn_plt_rel == NULL) {
320 scn_plt_rel = elf_section_by_name(elf, &ehdr, &shdr_rel_plt,
322 if (scn_plt_rel == NULL)
328 if (shdr_rel_plt.sh_link != dynsym_idx)
331 if (elf_section_by_name(elf, &ehdr, &shdr_plt, ".plt", NULL) == NULL)
335 * Fetch the relocation section to find the idxes to the GOT
336 * and the symbols in the .dynsym they refer to.
338 reldata = elf_getdata(scn_plt_rel, NULL);
342 syms = elf_getdata(scn_dynsym, NULL);
346 scn_symstrs = elf_getscn(elf, shdr_dynsym.sh_link);
347 if (scn_symstrs == NULL)
350 symstrs = elf_getdata(scn_symstrs, NULL);
354 if (symstrs->d_size == 0)
357 nr_rel_entries = shdr_rel_plt.sh_size / shdr_rel_plt.sh_entsize;
358 plt_offset = shdr_plt.sh_offset;
359 switch (ehdr.e_machine) {
361 plt_header_size = 20;
366 plt_header_size = 32;
371 plt_header_size = 48;
376 plt_header_size = 128;
380 default: /* FIXME: s390/alpha/mips/parisc/poperpc/sh/xtensa need to be checked */
381 plt_header_size = shdr_plt.sh_entsize;
382 plt_entry_size = shdr_plt.sh_entsize;
385 plt_offset += plt_header_size;
387 if (shdr_rel_plt.sh_type == SHT_RELA) {
388 GElf_Rela pos_mem, *pos;
390 elf_section__for_each_rela(reldata, pos, pos_mem, idx,
392 const char *elf_name = NULL;
393 char *demangled = NULL;
394 symidx = GELF_R_SYM(pos->r_info);
395 gelf_getsym(syms, symidx, &sym);
397 elf_name = elf_sym__name(&sym, symstrs);
398 demangled = demangle_sym(dso, 0, elf_name);
399 if (demangled != NULL)
400 elf_name = demangled;
401 snprintf(sympltname, sizeof(sympltname),
405 f = symbol__new(plt_offset, plt_entry_size,
406 STB_GLOBAL, STT_FUNC, sympltname);
410 plt_offset += plt_entry_size;
411 symbols__insert(&dso->symbols, f);
414 } else if (shdr_rel_plt.sh_type == SHT_REL) {
415 GElf_Rel pos_mem, *pos;
416 elf_section__for_each_rel(reldata, pos, pos_mem, idx,
418 const char *elf_name = NULL;
419 char *demangled = NULL;
420 symidx = GELF_R_SYM(pos->r_info);
421 gelf_getsym(syms, symidx, &sym);
423 elf_name = elf_sym__name(&sym, symstrs);
424 demangled = demangle_sym(dso, 0, elf_name);
425 if (demangled != NULL)
426 elf_name = demangled;
427 snprintf(sympltname, sizeof(sympltname),
431 f = symbol__new(plt_offset, plt_entry_size,
432 STB_GLOBAL, STT_FUNC, sympltname);
436 plt_offset += plt_entry_size;
437 symbols__insert(&dso->symbols, f);
446 pr_debug("%s: problems reading %s PLT info.\n",
447 __func__, dso->long_name);
451 char *dso__demangle_sym(struct dso *dso, int kmodule, const char *elf_name)
453 return demangle_sym(dso, kmodule, elf_name);
457 * Align offset to 4 bytes as needed for note name and descriptor data.
459 #define NOTE_ALIGN(n) (((n) + 3) & -4U)
461 static int elf_read_build_id(Elf *elf, void *bf, size_t size)
471 if (size < BUILD_ID_SIZE)
478 if (gelf_getehdr(elf, &ehdr) == NULL) {
479 pr_err("%s: cannot get elf header.\n", __func__);
484 * Check following sections for notes:
485 * '.note.gnu.build-id'
487 * '.note' (VDSO specific)
490 sec = elf_section_by_name(elf, &ehdr, &shdr,
491 ".note.gnu.build-id", NULL);
495 sec = elf_section_by_name(elf, &ehdr, &shdr,
500 sec = elf_section_by_name(elf, &ehdr, &shdr,
509 data = elf_getdata(sec, NULL);
514 while (ptr < (data->d_buf + data->d_size)) {
515 GElf_Nhdr *nhdr = ptr;
516 size_t namesz = NOTE_ALIGN(nhdr->n_namesz),
517 descsz = NOTE_ALIGN(nhdr->n_descsz);
520 ptr += sizeof(*nhdr);
523 if (nhdr->n_type == NT_GNU_BUILD_ID &&
524 nhdr->n_namesz == sizeof("GNU")) {
525 if (memcmp(name, "GNU", sizeof("GNU")) == 0) {
526 size_t sz = min(size, descsz);
528 memset(bf + sz, 0, size - sz);
540 #ifdef HAVE_LIBBFD_BUILDID_SUPPORT
542 static int read_build_id(const char *filename, struct build_id *bid)
544 size_t size = sizeof(bid->data);
548 abfd = bfd_openr(filename, NULL);
552 if (!bfd_check_format(abfd, bfd_object)) {
553 pr_debug2("%s: cannot read %s bfd file.\n", __func__, filename);
557 if (!abfd->build_id || abfd->build_id->size > size)
560 memcpy(bid->data, abfd->build_id->data, abfd->build_id->size);
561 memset(bid->data + abfd->build_id->size, 0, size - abfd->build_id->size);
562 err = bid->size = abfd->build_id->size;
569 #else // HAVE_LIBBFD_BUILDID_SUPPORT
571 static int read_build_id(const char *filename, struct build_id *bid)
573 size_t size = sizeof(bid->data);
577 if (size < BUILD_ID_SIZE)
580 fd = open(filename, O_RDONLY);
584 elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
586 pr_debug2("%s: cannot read %s ELF file.\n", __func__, filename);
590 err = elf_read_build_id(elf, bid->data, size);
601 #endif // HAVE_LIBBFD_BUILDID_SUPPORT
603 int filename__read_build_id(const char *filename, struct build_id *bid)
605 struct kmod_path m = { .name = NULL, };
612 err = kmod_path__parse(&m, filename);
619 fd = filename__decompress(filename, path, sizeof(path), m.comp, &error);
621 pr_debug("Failed to decompress (error %d) %s\n",
629 err = read_build_id(filename, bid);
636 int sysfs__read_build_id(const char *filename, struct build_id *bid)
638 size_t size = sizeof(bid->data);
641 fd = open(filename, O_RDONLY);
648 size_t namesz, descsz;
650 if (read(fd, &nhdr, sizeof(nhdr)) != sizeof(nhdr))
653 namesz = NOTE_ALIGN(nhdr.n_namesz);
654 descsz = NOTE_ALIGN(nhdr.n_descsz);
655 if (nhdr.n_type == NT_GNU_BUILD_ID &&
656 nhdr.n_namesz == sizeof("GNU")) {
657 if (read(fd, bf, namesz) != (ssize_t)namesz)
659 if (memcmp(bf, "GNU", sizeof("GNU")) == 0) {
660 size_t sz = min(descsz, size);
661 if (read(fd, bid->data, sz) == (ssize_t)sz) {
662 memset(bid->data + sz, 0, size - sz);
667 } else if (read(fd, bf, descsz) != (ssize_t)descsz)
670 int n = namesz + descsz;
672 if (n > (int)sizeof(bf)) {
674 pr_debug("%s: truncating reading of build id in sysfs file %s: n_namesz=%u, n_descsz=%u.\n",
675 __func__, filename, nhdr.n_namesz, nhdr.n_descsz);
677 if (read(fd, bf, n) != n)
686 #ifdef HAVE_LIBBFD_SUPPORT
688 int filename__read_debuglink(const char *filename, char *debuglink,
695 abfd = bfd_openr(filename, NULL);
699 if (!bfd_check_format(abfd, bfd_object)) {
700 pr_debug2("%s: cannot read %s bfd file.\n", __func__, filename);
704 section = bfd_get_section_by_name(abfd, ".gnu_debuglink");
708 if (section->size > size)
711 if (!bfd_get_section_contents(abfd, section, debuglink, 0,
724 int filename__read_debuglink(const char *filename, char *debuglink,
735 fd = open(filename, O_RDONLY);
739 elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
741 pr_debug2("%s: cannot read %s ELF file.\n", __func__, filename);
749 if (gelf_getehdr(elf, &ehdr) == NULL) {
750 pr_err("%s: cannot get elf header.\n", __func__);
754 sec = elf_section_by_name(elf, &ehdr, &shdr,
755 ".gnu_debuglink", NULL);
759 data = elf_getdata(sec, NULL);
763 /* the start of this section is a zero-terminated string */
764 strncpy(debuglink, data->d_buf, size);
778 static int dso__swap_init(struct dso *dso, unsigned char eidata)
780 static unsigned int const endian = 1;
782 dso->needs_swap = DSO_SWAP__NO;
786 /* We are big endian, DSO is little endian. */
787 if (*(unsigned char const *)&endian != 1)
788 dso->needs_swap = DSO_SWAP__YES;
792 /* We are little endian, DSO is big endian. */
793 if (*(unsigned char const *)&endian != 0)
794 dso->needs_swap = DSO_SWAP__YES;
798 pr_err("unrecognized DSO data encoding %d\n", eidata);
805 bool symsrc__possibly_runtime(struct symsrc *ss)
807 return ss->dynsym || ss->opdsec;
810 bool symsrc__has_symtab(struct symsrc *ss)
812 return ss->symtab != NULL;
815 void symsrc__destroy(struct symsrc *ss)
822 bool elf__needs_adjust_symbols(GElf_Ehdr ehdr)
825 * Usually vmlinux is an ELF file with type ET_EXEC for most
826 * architectures; except Arm64 kernel is linked with option
827 * '-share', so need to check type ET_DYN.
829 return ehdr.e_type == ET_EXEC || ehdr.e_type == ET_REL ||
830 ehdr.e_type == ET_DYN;
833 int symsrc__init(struct symsrc *ss, struct dso *dso, const char *name,
834 enum dso_binary_type type)
840 if (dso__needs_decompress(dso)) {
841 fd = dso__decompress_kmodule_fd(dso, name);
845 type = dso->symtab_type;
847 fd = open(name, O_RDONLY);
849 dso->load_errno = errno;
854 elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
856 pr_debug("%s: cannot read %s ELF file.\n", __func__, name);
857 dso->load_errno = DSO_LOAD_ERRNO__INVALID_ELF;
861 if (gelf_getehdr(elf, &ehdr) == NULL) {
862 dso->load_errno = DSO_LOAD_ERRNO__INVALID_ELF;
863 pr_debug("%s: cannot get elf header.\n", __func__);
867 if (dso__swap_init(dso, ehdr.e_ident[EI_DATA])) {
868 dso->load_errno = DSO_LOAD_ERRNO__INTERNAL_ERROR;
872 /* Always reject images with a mismatched build-id: */
873 if (dso->has_build_id && !symbol_conf.ignore_vmlinux_buildid) {
874 u8 build_id[BUILD_ID_SIZE];
878 size = elf_read_build_id(elf, build_id, BUILD_ID_SIZE);
880 dso->load_errno = DSO_LOAD_ERRNO__CANNOT_READ_BUILDID;
884 build_id__init(&bid, build_id, size);
885 if (!dso__build_id_equal(dso, &bid)) {
886 pr_debug("%s: build id mismatch for %s.\n", __func__, name);
887 dso->load_errno = DSO_LOAD_ERRNO__MISMATCHING_BUILDID;
892 ss->is_64_bit = (gelf_getclass(elf) == ELFCLASS64);
894 ss->symtab = elf_section_by_name(elf, &ehdr, &ss->symshdr, ".symtab",
896 if (ss->symshdr.sh_type != SHT_SYMTAB)
900 ss->dynsym = elf_section_by_name(elf, &ehdr, &ss->dynshdr, ".dynsym",
902 if (ss->dynshdr.sh_type != SHT_DYNSYM)
906 ss->opdsec = elf_section_by_name(elf, &ehdr, &ss->opdshdr, ".opd",
908 if (ss->opdshdr.sh_type != SHT_PROGBITS)
911 if (dso->kernel == DSO_SPACE__USER)
912 ss->adjust_symbols = true;
914 ss->adjust_symbols = elf__needs_adjust_symbols(ehdr);
916 ss->name = strdup(name);
918 dso->load_errno = errno;
937 * ref_reloc_sym_not_found - has kernel relocation symbol been found.
938 * @kmap: kernel maps and relocation reference symbol
940 * This function returns %true if we are dealing with the kernel maps and the
941 * relocation reference symbol has not yet been found. Otherwise %false is
944 static bool ref_reloc_sym_not_found(struct kmap *kmap)
946 return kmap && kmap->ref_reloc_sym && kmap->ref_reloc_sym->name &&
947 !kmap->ref_reloc_sym->unrelocated_addr;
951 * ref_reloc - kernel relocation offset.
952 * @kmap: kernel maps and relocation reference symbol
954 * This function returns the offset of kernel addresses as determined by using
955 * the relocation reference symbol i.e. if the kernel has not been relocated
956 * then the return value is zero.
958 static u64 ref_reloc(struct kmap *kmap)
960 if (kmap && kmap->ref_reloc_sym &&
961 kmap->ref_reloc_sym->unrelocated_addr)
962 return kmap->ref_reloc_sym->addr -
963 kmap->ref_reloc_sym->unrelocated_addr;
967 void __weak arch__sym_update(struct symbol *s __maybe_unused,
968 GElf_Sym *sym __maybe_unused) { }
970 static int dso__process_kernel_symbol(struct dso *dso, struct map *map,
971 GElf_Sym *sym, GElf_Shdr *shdr,
972 struct maps *kmaps, struct kmap *kmap,
973 struct dso **curr_dsop, struct map **curr_mapp,
974 const char *section_name,
975 bool adjust_kernel_syms, bool kmodule, bool *remap_kernel)
977 struct dso *curr_dso = *curr_dsop;
978 struct map *curr_map;
979 char dso_name[PATH_MAX];
981 /* Adjust symbol to map to file offset */
982 if (adjust_kernel_syms)
983 sym->st_value -= shdr->sh_addr - shdr->sh_offset;
985 if (strcmp(section_name, (curr_dso->short_name + dso->short_name_len)) == 0)
988 if (strcmp(section_name, ".text") == 0) {
990 * The initial kernel mapping is based on
991 * kallsyms and identity maps. Overwrite it to
992 * map to the kernel dso.
994 if (*remap_kernel && dso->kernel && !kmodule) {
995 *remap_kernel = false;
996 map->start = shdr->sh_addr + ref_reloc(kmap);
997 map->end = map->start + shdr->sh_size;
998 map->pgoff = shdr->sh_offset;
999 map->map_ip = map__map_ip;
1000 map->unmap_ip = map__unmap_ip;
1001 /* Ensure maps are correctly ordered */
1004 maps__remove(kmaps, map);
1005 maps__insert(kmaps, map);
1011 * The initial module mapping is based on
1012 * /proc/modules mapped to offset zero.
1013 * Overwrite it to map to the module dso.
1015 if (*remap_kernel && kmodule) {
1016 *remap_kernel = false;
1017 map->pgoff = shdr->sh_offset;
1028 snprintf(dso_name, sizeof(dso_name), "%s%s", dso->short_name, section_name);
1030 curr_map = maps__find_by_name(kmaps, dso_name);
1031 if (curr_map == NULL) {
1032 u64 start = sym->st_value;
1035 start += map->start + shdr->sh_offset;
1037 curr_dso = dso__new(dso_name);
1038 if (curr_dso == NULL)
1040 curr_dso->kernel = dso->kernel;
1041 curr_dso->long_name = dso->long_name;
1042 curr_dso->long_name_len = dso->long_name_len;
1043 curr_map = map__new2(start, curr_dso);
1045 if (curr_map == NULL)
1048 if (curr_dso->kernel)
1049 map__kmap(curr_map)->kmaps = kmaps;
1051 if (adjust_kernel_syms) {
1052 curr_map->start = shdr->sh_addr + ref_reloc(kmap);
1053 curr_map->end = curr_map->start + shdr->sh_size;
1054 curr_map->pgoff = shdr->sh_offset;
1056 curr_map->map_ip = curr_map->unmap_ip = identity__map_ip;
1058 curr_dso->symtab_type = dso->symtab_type;
1059 maps__insert(kmaps, curr_map);
1061 * Add it before we drop the reference to curr_map, i.e. while
1062 * we still are sure to have a reference to this DSO via
1065 dsos__add(&kmaps->machine->dsos, curr_dso);
1066 /* kmaps already got it */
1068 dso__set_loaded(curr_dso);
1069 *curr_mapp = curr_map;
1070 *curr_dsop = curr_dso;
1072 *curr_dsop = curr_map->dso;
1078 dso__load_sym_internal(struct dso *dso, struct map *map, struct symsrc *syms_ss,
1079 struct symsrc *runtime_ss, int kmodule, int dynsym)
1081 struct kmap *kmap = dso->kernel ? map__kmap(map) : NULL;
1082 struct maps *kmaps = kmap ? map__kmaps(map) : NULL;
1083 struct map *curr_map = map;
1084 struct dso *curr_dso = dso;
1085 Elf_Data *symstrs, *secstrs, *secstrs_run, *secstrs_sym;
1092 Elf_Data *syms, *opddata = NULL;
1094 Elf_Scn *sec, *sec_strndx;
1097 bool remap_kernel = false, adjust_kernel_syms = false;
1103 ehdr = syms_ss->ehdr;
1105 sec = syms_ss->dynsym;
1106 shdr = syms_ss->dynshdr;
1108 sec = syms_ss->symtab;
1109 shdr = syms_ss->symshdr;
1112 if (elf_section_by_name(runtime_ss->elf, &runtime_ss->ehdr, &tshdr,
1114 dso->text_offset = tshdr.sh_addr - tshdr.sh_offset;
1116 if (runtime_ss->opdsec)
1117 opddata = elf_rawdata(runtime_ss->opdsec, NULL);
1119 syms = elf_getdata(sec, NULL);
1123 sec = elf_getscn(elf, shdr.sh_link);
1127 symstrs = elf_getdata(sec, NULL);
1128 if (symstrs == NULL)
1131 sec_strndx = elf_getscn(runtime_ss->elf, runtime_ss->ehdr.e_shstrndx);
1132 if (sec_strndx == NULL)
1135 secstrs_run = elf_getdata(sec_strndx, NULL);
1136 if (secstrs_run == NULL)
1139 sec_strndx = elf_getscn(elf, ehdr.e_shstrndx);
1140 if (sec_strndx == NULL)
1143 secstrs_sym = elf_getdata(sec_strndx, NULL);
1144 if (secstrs_sym == NULL)
1147 nr_syms = shdr.sh_size / shdr.sh_entsize;
1149 memset(&sym, 0, sizeof(sym));
1152 * The kernel relocation symbol is needed in advance in order to adjust
1153 * kernel maps correctly.
1155 if (ref_reloc_sym_not_found(kmap)) {
1156 elf_symtab__for_each_symbol(syms, nr_syms, idx, sym) {
1157 const char *elf_name = elf_sym__name(&sym, symstrs);
1159 if (strcmp(elf_name, kmap->ref_reloc_sym->name))
1161 kmap->ref_reloc_sym->unrelocated_addr = sym.st_value;
1162 map->reloc = kmap->ref_reloc_sym->addr -
1163 kmap->ref_reloc_sym->unrelocated_addr;
1169 * Handle any relocation of vdso necessary because older kernels
1170 * attempted to prelink vdso to its virtual address.
1172 if (dso__is_vdso(dso))
1173 map->reloc = map->start - dso->text_offset;
1175 dso->adjust_symbols = runtime_ss->adjust_symbols || ref_reloc(kmap);
1177 * Initial kernel and module mappings do not map to the dso.
1181 remap_kernel = true;
1182 adjust_kernel_syms = dso->adjust_symbols;
1184 elf_symtab__for_each_symbol(syms, nr_syms, idx, sym) {
1186 const char *elf_name = elf_sym__name(&sym, symstrs);
1187 char *demangled = NULL;
1188 int is_label = elf_sym__is_label(&sym);
1189 const char *section_name;
1190 bool used_opd = false;
1192 if (!is_label && !elf_sym__filter(&sym))
1195 /* Reject ARM ELF "mapping symbols": these aren't unique and
1196 * don't identify functions, so will confuse the profile
1198 if (ehdr.e_machine == EM_ARM || ehdr.e_machine == EM_AARCH64) {
1199 if (elf_name[0] == '$' && strchr("adtx", elf_name[1])
1200 && (elf_name[2] == '\0' || elf_name[2] == '.'))
1204 if (runtime_ss->opdsec && sym.st_shndx == runtime_ss->opdidx) {
1205 u32 offset = sym.st_value - syms_ss->opdshdr.sh_addr;
1206 u64 *opd = opddata->d_buf + offset;
1207 sym.st_value = DSO__SWAP(dso, u64, *opd);
1208 sym.st_shndx = elf_addr_to_index(runtime_ss->elf,
1213 * When loading symbols in a data mapping, ABS symbols (which
1214 * has a value of SHN_ABS in its st_shndx) failed at
1215 * elf_getscn(). And it marks the loading as a failure so
1216 * already loaded symbols cannot be fixed up.
1218 * I'm not sure what should be done. Just ignore them for now.
1221 if (sym.st_shndx == SHN_ABS)
1224 sec = elf_getscn(syms_ss->elf, sym.st_shndx);
1228 gelf_getshdr(sec, &shdr);
1230 secstrs = secstrs_sym;
1233 * We have to fallback to runtime when syms' section header has
1234 * NOBITS set. NOBITS results in file offset (sh_offset) not
1235 * being incremented. So sh_offset used below has different
1236 * values for syms (invalid) and runtime (valid).
1238 if (shdr.sh_type == SHT_NOBITS) {
1239 sec = elf_getscn(runtime_ss->elf, sym.st_shndx);
1243 gelf_getshdr(sec, &shdr);
1244 secstrs = secstrs_run;
1247 if (is_label && !elf_sec__filter(&shdr, secstrs))
1250 section_name = elf_sec__name(&shdr, secstrs);
1252 /* On ARM, symbols for thumb functions have 1 added to
1253 * the symbol address as a flag - remove it */
1254 if ((ehdr.e_machine == EM_ARM) &&
1255 (GELF_ST_TYPE(sym.st_info) == STT_FUNC) &&
1260 if (dso__process_kernel_symbol(dso, map, &sym, &shdr, kmaps, kmap, &curr_dso, &curr_map,
1261 section_name, adjust_kernel_syms, kmodule, &remap_kernel))
1263 } else if ((used_opd && runtime_ss->adjust_symbols) ||
1264 (!used_opd && syms_ss->adjust_symbols)) {
1265 pr_debug4("%s: adjusting symbol: st_value: %#" PRIx64 " "
1266 "sh_addr: %#" PRIx64 " sh_offset: %#" PRIx64 "\n", __func__,
1267 (u64)sym.st_value, (u64)shdr.sh_addr,
1268 (u64)shdr.sh_offset);
1269 sym.st_value -= shdr.sh_addr - shdr.sh_offset;
1272 demangled = demangle_sym(dso, kmodule, elf_name);
1273 if (demangled != NULL)
1274 elf_name = demangled;
1276 f = symbol__new(sym.st_value, sym.st_size,
1277 GELF_ST_BIND(sym.st_info),
1278 GELF_ST_TYPE(sym.st_info), elf_name);
1283 arch__sym_update(f, &sym);
1285 __symbols__insert(&curr_dso->symbols, f, dso->kernel);
1290 * For misannotated, zeroed, ASM function sizes.
1293 symbols__fixup_end(&dso->symbols);
1294 symbols__fixup_duplicate(&dso->symbols);
1297 * We need to fixup this here too because we create new
1298 * maps here, for things like vsyscall sections.
1300 maps__fixup_end(kmaps);
1308 int dso__load_sym(struct dso *dso, struct map *map, struct symsrc *syms_ss,
1309 struct symsrc *runtime_ss, int kmodule)
1314 dso->symtab_type = syms_ss->type;
1315 dso->is_64_bit = syms_ss->is_64_bit;
1316 dso->rel = syms_ss->ehdr.e_type == ET_REL;
1319 * Modules may already have symbols from kallsyms, but those symbols
1320 * have the wrong values for the dso maps, so remove them.
1322 if (kmodule && syms_ss->symtab)
1323 symbols__delete(&dso->symbols);
1325 if (!syms_ss->symtab) {
1327 * If the vmlinux is stripped, fail so we will fall back
1328 * to using kallsyms. The vmlinux runtime symbols aren't
1334 err = dso__load_sym_internal(dso, map, syms_ss, runtime_ss,
1341 if (syms_ss->dynsym) {
1342 err = dso__load_sym_internal(dso, map, syms_ss, runtime_ss,
1352 static int elf_read_maps(Elf *elf, bool exe, mapfn_t mapfn, void *data)
1359 if (elf_getphdrnum(elf, &phdrnum))
1362 for (i = 0; i < phdrnum; i++) {
1363 if (gelf_getphdr(elf, i, &phdr) == NULL)
1365 if (phdr.p_type != PT_LOAD)
1368 if (!(phdr.p_flags & PF_X))
1371 if (!(phdr.p_flags & PF_R))
1374 sz = min(phdr.p_memsz, phdr.p_filesz);
1377 err = mapfn(phdr.p_vaddr, sz, phdr.p_offset, data);
1384 int file__read_maps(int fd, bool exe, mapfn_t mapfn, void *data,
1390 elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
1395 *is_64_bit = (gelf_getclass(elf) == ELFCLASS64);
1397 err = elf_read_maps(elf, exe, mapfn, data);
1403 enum dso_type dso__type_fd(int fd)
1405 enum dso_type dso_type = DSO__TYPE_UNKNOWN;
1410 elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
1415 if (ek != ELF_K_ELF)
1418 if (gelf_getclass(elf) == ELFCLASS64) {
1419 dso_type = DSO__TYPE_64BIT;
1423 if (gelf_getehdr(elf, &ehdr) == NULL)
1426 if (ehdr.e_machine == EM_X86_64)
1427 dso_type = DSO__TYPE_X32BIT;
1429 dso_type = DSO__TYPE_32BIT;
1436 static int copy_bytes(int from, off_t from_offs, int to, off_t to_offs, u64 len)
1441 char *buf = malloc(page_size);
1446 if (lseek(to, to_offs, SEEK_SET) != to_offs)
1449 if (lseek(from, from_offs, SEEK_SET) != from_offs)
1456 /* Use read because mmap won't work on proc files */
1457 r = read(from, buf, n);
1463 r = write(to, buf, n);
1484 static int kcore__open(struct kcore *kcore, const char *filename)
1488 kcore->fd = open(filename, O_RDONLY);
1489 if (kcore->fd == -1)
1492 kcore->elf = elf_begin(kcore->fd, ELF_C_READ, NULL);
1496 kcore->elfclass = gelf_getclass(kcore->elf);
1497 if (kcore->elfclass == ELFCLASSNONE)
1500 ehdr = gelf_getehdr(kcore->elf, &kcore->ehdr);
1507 elf_end(kcore->elf);
1513 static int kcore__init(struct kcore *kcore, char *filename, int elfclass,
1516 kcore->elfclass = elfclass;
1519 kcore->fd = mkstemp(filename);
1521 kcore->fd = open(filename, O_WRONLY | O_CREAT | O_EXCL, 0400);
1522 if (kcore->fd == -1)
1525 kcore->elf = elf_begin(kcore->fd, ELF_C_WRITE, NULL);
1529 if (!gelf_newehdr(kcore->elf, elfclass))
1532 memset(&kcore->ehdr, 0, sizeof(GElf_Ehdr));
1537 elf_end(kcore->elf);
1544 static void kcore__close(struct kcore *kcore)
1546 elf_end(kcore->elf);
1550 static int kcore__copy_hdr(struct kcore *from, struct kcore *to, size_t count)
1552 GElf_Ehdr *ehdr = &to->ehdr;
1553 GElf_Ehdr *kehdr = &from->ehdr;
1555 memcpy(ehdr->e_ident, kehdr->e_ident, EI_NIDENT);
1556 ehdr->e_type = kehdr->e_type;
1557 ehdr->e_machine = kehdr->e_machine;
1558 ehdr->e_version = kehdr->e_version;
1561 ehdr->e_flags = kehdr->e_flags;
1562 ehdr->e_phnum = count;
1563 ehdr->e_shentsize = 0;
1565 ehdr->e_shstrndx = 0;
1567 if (from->elfclass == ELFCLASS32) {
1568 ehdr->e_phoff = sizeof(Elf32_Ehdr);
1569 ehdr->e_ehsize = sizeof(Elf32_Ehdr);
1570 ehdr->e_phentsize = sizeof(Elf32_Phdr);
1572 ehdr->e_phoff = sizeof(Elf64_Ehdr);
1573 ehdr->e_ehsize = sizeof(Elf64_Ehdr);
1574 ehdr->e_phentsize = sizeof(Elf64_Phdr);
1577 if (!gelf_update_ehdr(to->elf, ehdr))
1580 if (!gelf_newphdr(to->elf, count))
1586 static int kcore__add_phdr(struct kcore *kcore, int idx, off_t offset,
1591 .p_flags = PF_R | PF_W | PF_X,
1597 .p_align = page_size,
1600 if (!gelf_update_phdr(kcore->elf, idx, &phdr))
1606 static off_t kcore__write(struct kcore *kcore)
1608 return elf_update(kcore->elf, ELF_C_WRITE);
1616 struct list_head node;
1617 struct phdr_data *remaps;
1622 struct list_head node;
1625 struct kcore_copy_info {
1631 u64 first_module_symbol;
1632 u64 last_module_symbol;
1634 struct list_head phdrs;
1635 struct list_head syms;
1638 #define kcore_copy__for_each_phdr(k, p) \
1639 list_for_each_entry((p), &(k)->phdrs, node)
1641 static struct phdr_data *phdr_data__new(u64 addr, u64 len, off_t offset)
1643 struct phdr_data *p = zalloc(sizeof(*p));
1654 static struct phdr_data *kcore_copy_info__addnew(struct kcore_copy_info *kci,
1658 struct phdr_data *p = phdr_data__new(addr, len, offset);
1661 list_add_tail(&p->node, &kci->phdrs);
1666 static void kcore_copy__free_phdrs(struct kcore_copy_info *kci)
1668 struct phdr_data *p, *tmp;
1670 list_for_each_entry_safe(p, tmp, &kci->phdrs, node) {
1671 list_del_init(&p->node);
1676 static struct sym_data *kcore_copy__new_sym(struct kcore_copy_info *kci,
1679 struct sym_data *s = zalloc(sizeof(*s));
1683 list_add_tail(&s->node, &kci->syms);
1689 static void kcore_copy__free_syms(struct kcore_copy_info *kci)
1691 struct sym_data *s, *tmp;
1693 list_for_each_entry_safe(s, tmp, &kci->syms, node) {
1694 list_del_init(&s->node);
1699 static int kcore_copy__process_kallsyms(void *arg, const char *name, char type,
1702 struct kcore_copy_info *kci = arg;
1704 if (!kallsyms__is_function(type))
1707 if (strchr(name, '[')) {
1708 if (!kci->first_module_symbol || start < kci->first_module_symbol)
1709 kci->first_module_symbol = start;
1710 if (start > kci->last_module_symbol)
1711 kci->last_module_symbol = start;
1715 if (!kci->first_symbol || start < kci->first_symbol)
1716 kci->first_symbol = start;
1718 if (!kci->last_symbol || start > kci->last_symbol)
1719 kci->last_symbol = start;
1721 if (!strcmp(name, "_stext")) {
1726 if (!strcmp(name, "_etext")) {
1731 if (is_entry_trampoline(name) && !kcore_copy__new_sym(kci, start))
1737 static int kcore_copy__parse_kallsyms(struct kcore_copy_info *kci,
1740 char kallsyms_filename[PATH_MAX];
1742 scnprintf(kallsyms_filename, PATH_MAX, "%s/kallsyms", dir);
1744 if (symbol__restricted_filename(kallsyms_filename, "/proc/kallsyms"))
1747 if (kallsyms__parse(kallsyms_filename, kci,
1748 kcore_copy__process_kallsyms) < 0)
1754 static int kcore_copy__process_modules(void *arg,
1755 const char *name __maybe_unused,
1756 u64 start, u64 size __maybe_unused)
1758 struct kcore_copy_info *kci = arg;
1760 if (!kci->first_module || start < kci->first_module)
1761 kci->first_module = start;
1766 static int kcore_copy__parse_modules(struct kcore_copy_info *kci,
1769 char modules_filename[PATH_MAX];
1771 scnprintf(modules_filename, PATH_MAX, "%s/modules", dir);
1773 if (symbol__restricted_filename(modules_filename, "/proc/modules"))
1776 if (modules__parse(modules_filename, kci,
1777 kcore_copy__process_modules) < 0)
1783 static int kcore_copy__map(struct kcore_copy_info *kci, u64 start, u64 end,
1784 u64 pgoff, u64 s, u64 e)
1788 if (s < start || s >= end)
1791 offset = (s - start) + pgoff;
1792 len = e < end ? e - s : end - s;
1794 return kcore_copy_info__addnew(kci, s, len, offset) ? 0 : -1;
1797 static int kcore_copy__read_map(u64 start, u64 len, u64 pgoff, void *data)
1799 struct kcore_copy_info *kci = data;
1800 u64 end = start + len;
1801 struct sym_data *sdat;
1803 if (kcore_copy__map(kci, start, end, pgoff, kci->stext, kci->etext))
1806 if (kcore_copy__map(kci, start, end, pgoff, kci->first_module,
1807 kci->last_module_symbol))
1810 list_for_each_entry(sdat, &kci->syms, node) {
1811 u64 s = round_down(sdat->addr, page_size);
1813 if (kcore_copy__map(kci, start, end, pgoff, s, s + len))
1820 static int kcore_copy__read_maps(struct kcore_copy_info *kci, Elf *elf)
1822 if (elf_read_maps(elf, true, kcore_copy__read_map, kci) < 0)
1828 static void kcore_copy__find_remaps(struct kcore_copy_info *kci)
1830 struct phdr_data *p, *k = NULL;
1836 /* Find phdr that corresponds to the kernel map (contains stext) */
1837 kcore_copy__for_each_phdr(kci, p) {
1838 u64 pend = p->addr + p->len - 1;
1840 if (p->addr <= kci->stext && pend >= kci->stext) {
1849 kend = k->offset + k->len;
1851 /* Find phdrs that remap the kernel */
1852 kcore_copy__for_each_phdr(kci, p) {
1853 u64 pend = p->offset + p->len;
1858 if (p->offset >= k->offset && pend <= kend)
1863 static void kcore_copy__layout(struct kcore_copy_info *kci)
1865 struct phdr_data *p;
1868 kcore_copy__find_remaps(kci);
1870 kcore_copy__for_each_phdr(kci, p) {
1878 kcore_copy__for_each_phdr(kci, p) {
1879 struct phdr_data *k = p->remaps;
1882 p->rel = p->offset - k->offset + k->rel;
1886 static int kcore_copy__calc_maps(struct kcore_copy_info *kci, const char *dir,
1889 if (kcore_copy__parse_kallsyms(kci, dir))
1892 if (kcore_copy__parse_modules(kci, dir))
1896 kci->stext = round_down(kci->stext, page_size);
1898 kci->stext = round_down(kci->first_symbol, page_size);
1901 kci->etext = round_up(kci->etext, page_size);
1902 } else if (kci->last_symbol) {
1903 kci->etext = round_up(kci->last_symbol, page_size);
1904 kci->etext += page_size;
1907 if (kci->first_module_symbol &&
1908 (!kci->first_module || kci->first_module_symbol < kci->first_module))
1909 kci->first_module = kci->first_module_symbol;
1911 kci->first_module = round_down(kci->first_module, page_size);
1913 if (kci->last_module_symbol) {
1914 kci->last_module_symbol = round_up(kci->last_module_symbol,
1916 kci->last_module_symbol += page_size;
1919 if (!kci->stext || !kci->etext)
1922 if (kci->first_module && !kci->last_module_symbol)
1925 if (kcore_copy__read_maps(kci, elf))
1928 kcore_copy__layout(kci);
1933 static int kcore_copy__copy_file(const char *from_dir, const char *to_dir,
1936 char from_filename[PATH_MAX];
1937 char to_filename[PATH_MAX];
1939 scnprintf(from_filename, PATH_MAX, "%s/%s", from_dir, name);
1940 scnprintf(to_filename, PATH_MAX, "%s/%s", to_dir, name);
1942 return copyfile_mode(from_filename, to_filename, 0400);
1945 static int kcore_copy__unlink(const char *dir, const char *name)
1947 char filename[PATH_MAX];
1949 scnprintf(filename, PATH_MAX, "%s/%s", dir, name);
1951 return unlink(filename);
1954 static int kcore_copy__compare_fds(int from, int to)
1962 buf_from = malloc(page_size);
1963 buf_to = malloc(page_size);
1964 if (!buf_from || !buf_to)
1968 /* Use read because mmap won't work on proc files */
1969 ret = read(from, buf_from, page_size);
1978 if (readn(to, buf_to, len) != (int)len)
1981 if (memcmp(buf_from, buf_to, len))
1992 static int kcore_copy__compare_files(const char *from_filename,
1993 const char *to_filename)
1995 int from, to, err = -1;
1997 from = open(from_filename, O_RDONLY);
2001 to = open(to_filename, O_RDONLY);
2003 goto out_close_from;
2005 err = kcore_copy__compare_fds(from, to);
2013 static int kcore_copy__compare_file(const char *from_dir, const char *to_dir,
2016 char from_filename[PATH_MAX];
2017 char to_filename[PATH_MAX];
2019 scnprintf(from_filename, PATH_MAX, "%s/%s", from_dir, name);
2020 scnprintf(to_filename, PATH_MAX, "%s/%s", to_dir, name);
2022 return kcore_copy__compare_files(from_filename, to_filename);
2026 * kcore_copy - copy kallsyms, modules and kcore from one directory to another.
2027 * @from_dir: from directory
2028 * @to_dir: to directory
2030 * This function copies kallsyms, modules and kcore files from one directory to
2031 * another. kallsyms and modules are copied entirely. Only code segments are
2032 * copied from kcore. It is assumed that two segments suffice: one for the
2033 * kernel proper and one for all the modules. The code segments are determined
2034 * from kallsyms and modules files. The kernel map starts at _stext or the
2035 * lowest function symbol, and ends at _etext or the highest function symbol.
2036 * The module map starts at the lowest module address and ends at the highest
2037 * module symbol. Start addresses are rounded down to the nearest page. End
2038 * addresses are rounded up to the nearest page. An extra page is added to the
2039 * highest kernel symbol and highest module symbol to, hopefully, encompass that
2040 * symbol too. Because it contains only code sections, the resulting kcore is
2041 * unusual. One significant peculiarity is that the mapping (start -> pgoff)
2042 * is not the same for the kernel map and the modules map. That happens because
2043 * the data is copied adjacently whereas the original kcore has gaps. Finally,
2044 * kallsyms and modules files are compared with their copies to check that
2045 * modules have not been loaded or unloaded while the copies were taking place.
2047 * Return: %0 on success, %-1 on failure.
2049 int kcore_copy(const char *from_dir, const char *to_dir)
2052 struct kcore extract;
2053 int idx = 0, err = -1;
2055 struct kcore_copy_info kci = { .stext = 0, };
2056 char kcore_filename[PATH_MAX];
2057 char extract_filename[PATH_MAX];
2058 struct phdr_data *p;
2060 INIT_LIST_HEAD(&kci.phdrs);
2061 INIT_LIST_HEAD(&kci.syms);
2063 if (kcore_copy__copy_file(from_dir, to_dir, "kallsyms"))
2066 if (kcore_copy__copy_file(from_dir, to_dir, "modules"))
2067 goto out_unlink_kallsyms;
2069 scnprintf(kcore_filename, PATH_MAX, "%s/kcore", from_dir);
2070 scnprintf(extract_filename, PATH_MAX, "%s/kcore", to_dir);
2072 if (kcore__open(&kcore, kcore_filename))
2073 goto out_unlink_modules;
2075 if (kcore_copy__calc_maps(&kci, from_dir, kcore.elf))
2076 goto out_kcore_close;
2078 if (kcore__init(&extract, extract_filename, kcore.elfclass, false))
2079 goto out_kcore_close;
2081 if (kcore__copy_hdr(&kcore, &extract, kci.phnum))
2082 goto out_extract_close;
2084 offset = gelf_fsize(extract.elf, ELF_T_EHDR, 1, EV_CURRENT) +
2085 gelf_fsize(extract.elf, ELF_T_PHDR, kci.phnum, EV_CURRENT);
2086 offset = round_up(offset, page_size);
2088 kcore_copy__for_each_phdr(&kci, p) {
2089 off_t offs = p->rel + offset;
2091 if (kcore__add_phdr(&extract, idx++, offs, p->addr, p->len))
2092 goto out_extract_close;
2095 sz = kcore__write(&extract);
2096 if (sz < 0 || sz > offset)
2097 goto out_extract_close;
2099 kcore_copy__for_each_phdr(&kci, p) {
2100 off_t offs = p->rel + offset;
2104 if (copy_bytes(kcore.fd, p->offset, extract.fd, offs, p->len))
2105 goto out_extract_close;
2108 if (kcore_copy__compare_file(from_dir, to_dir, "modules"))
2109 goto out_extract_close;
2111 if (kcore_copy__compare_file(from_dir, to_dir, "kallsyms"))
2112 goto out_extract_close;
2117 kcore__close(&extract);
2119 unlink(extract_filename);
2121 kcore__close(&kcore);
2124 kcore_copy__unlink(to_dir, "modules");
2125 out_unlink_kallsyms:
2127 kcore_copy__unlink(to_dir, "kallsyms");
2129 kcore_copy__free_phdrs(&kci);
2130 kcore_copy__free_syms(&kci);
2135 int kcore_extract__create(struct kcore_extract *kce)
2138 struct kcore extract;
2140 int idx = 0, err = -1;
2141 off_t offset = page_size, sz;
2143 if (kcore__open(&kcore, kce->kcore_filename))
2146 strcpy(kce->extract_filename, PERF_KCORE_EXTRACT);
2147 if (kcore__init(&extract, kce->extract_filename, kcore.elfclass, true))
2148 goto out_kcore_close;
2150 if (kcore__copy_hdr(&kcore, &extract, count))
2151 goto out_extract_close;
2153 if (kcore__add_phdr(&extract, idx, offset, kce->addr, kce->len))
2154 goto out_extract_close;
2156 sz = kcore__write(&extract);
2157 if (sz < 0 || sz > offset)
2158 goto out_extract_close;
2160 if (copy_bytes(kcore.fd, kce->offs, extract.fd, offset, kce->len))
2161 goto out_extract_close;
2166 kcore__close(&extract);
2168 unlink(kce->extract_filename);
2170 kcore__close(&kcore);
2175 void kcore_extract__delete(struct kcore_extract *kce)
2177 unlink(kce->extract_filename);
2180 #ifdef HAVE_GELF_GETNOTE_SUPPORT
2182 static void sdt_adjust_loc(struct sdt_note *tmp, GElf_Addr base_off)
2188 tmp->addr.a32[SDT_NOTE_IDX_LOC] =
2189 tmp->addr.a32[SDT_NOTE_IDX_LOC] + base_off -
2190 tmp->addr.a32[SDT_NOTE_IDX_BASE];
2192 tmp->addr.a64[SDT_NOTE_IDX_LOC] =
2193 tmp->addr.a64[SDT_NOTE_IDX_LOC] + base_off -
2194 tmp->addr.a64[SDT_NOTE_IDX_BASE];
2197 static void sdt_adjust_refctr(struct sdt_note *tmp, GElf_Addr base_addr,
2203 if (tmp->bit32 && tmp->addr.a32[SDT_NOTE_IDX_REFCTR])
2204 tmp->addr.a32[SDT_NOTE_IDX_REFCTR] -= (base_addr - base_off);
2205 else if (tmp->addr.a64[SDT_NOTE_IDX_REFCTR])
2206 tmp->addr.a64[SDT_NOTE_IDX_REFCTR] -= (base_addr - base_off);
2210 * populate_sdt_note : Parse raw data and identify SDT note
2211 * @elf: elf of the opened file
2212 * @data: raw data of a section with description offset applied
2213 * @len: note description size
2214 * @type: type of the note
2215 * @sdt_notes: List to add the SDT note
2217 * Responsible for parsing the @data in section .note.stapsdt in @elf and
2218 * if its an SDT note, it appends to @sdt_notes list.
2220 static int populate_sdt_note(Elf **elf, const char *data, size_t len,
2221 struct list_head *sdt_notes)
2223 const char *provider, *name, *args;
2224 struct sdt_note *tmp = NULL;
2230 Elf64_Addr a64[NR_ADDR];
2231 Elf32_Addr a32[NR_ADDR];
2235 .d_buf = &buf, .d_type = ELF_T_ADDR, .d_version = EV_CURRENT,
2236 .d_size = gelf_fsize((*elf), ELF_T_ADDR, NR_ADDR, EV_CURRENT),
2237 .d_off = 0, .d_align = 0
2240 .d_buf = (void *) data, .d_type = ELF_T_ADDR,
2241 .d_version = EV_CURRENT, .d_size = dst.d_size, .d_off = 0,
2245 tmp = (struct sdt_note *)calloc(1, sizeof(struct sdt_note));
2251 INIT_LIST_HEAD(&tmp->note_list);
2253 if (len < dst.d_size + 3)
2256 /* Translation from file representation to memory representation */
2257 if (gelf_xlatetom(*elf, &dst, &src,
2258 elf_getident(*elf, NULL)[EI_DATA]) == NULL) {
2259 pr_err("gelf_xlatetom : %s\n", elf_errmsg(-1));
2263 /* Populate the fields of sdt_note */
2264 provider = data + dst.d_size;
2266 name = (const char *)memchr(provider, '\0', data + len - provider);
2270 tmp->provider = strdup(provider);
2271 if (!tmp->provider) {
2275 tmp->name = strdup(name);
2281 args = memchr(name, '\0', data + len - name);
2284 * There is no argument if:
2285 * - We reached the end of the note;
2286 * - There is not enough room to hold a potential string;
2287 * - The argument string is empty or just contains ':'.
2289 if (args == NULL || data + len - args < 2 ||
2290 args[1] == ':' || args[1] == '\0')
2293 tmp->args = strdup(++args);
2300 if (gelf_getclass(*elf) == ELFCLASS32) {
2301 memcpy(&tmp->addr, &buf, 3 * sizeof(Elf32_Addr));
2304 memcpy(&tmp->addr, &buf, 3 * sizeof(Elf64_Addr));
2308 if (!gelf_getehdr(*elf, &ehdr)) {
2309 pr_debug("%s : cannot get elf header.\n", __func__);
2314 /* Adjust the prelink effect :
2315 * Find out the .stapsdt.base section.
2316 * This scn will help us to handle prelinking (if present).
2317 * Compare the retrieved file offset of the base section with the
2318 * base address in the description of the SDT note. If its different,
2319 * then accordingly, adjust the note location.
2321 if (elf_section_by_name(*elf, &ehdr, &shdr, SDT_BASE_SCN, NULL))
2322 sdt_adjust_loc(tmp, shdr.sh_offset);
2324 /* Adjust reference counter offset */
2325 if (elf_section_by_name(*elf, &ehdr, &shdr, SDT_PROBES_SCN, NULL))
2326 sdt_adjust_refctr(tmp, shdr.sh_addr, shdr.sh_offset);
2328 list_add_tail(&tmp->note_list, sdt_notes);
2336 zfree(&tmp->provider);
2344 * construct_sdt_notes_list : constructs a list of SDT notes
2345 * @elf : elf to look into
2346 * @sdt_notes : empty list_head
2348 * Scans the sections in 'elf' for the section
2349 * .note.stapsdt. It, then calls populate_sdt_note to find
2350 * out the SDT events and populates the 'sdt_notes'.
2352 static int construct_sdt_notes_list(Elf *elf, struct list_head *sdt_notes)
2355 Elf_Scn *scn = NULL;
2358 size_t shstrndx, next;
2360 size_t name_off, desc_off, offset;
2363 if (gelf_getehdr(elf, &ehdr) == NULL) {
2367 if (elf_getshdrstrndx(elf, &shstrndx) != 0) {
2372 /* Look for the required section */
2373 scn = elf_section_by_name(elf, &ehdr, &shdr, SDT_NOTE_SCN, NULL);
2379 if ((shdr.sh_type != SHT_NOTE) || (shdr.sh_flags & SHF_ALLOC)) {
2384 data = elf_getdata(scn, NULL);
2386 /* Get the SDT notes */
2387 for (offset = 0; (next = gelf_getnote(data, offset, &nhdr, &name_off,
2388 &desc_off)) > 0; offset = next) {
2389 if (nhdr.n_namesz == sizeof(SDT_NOTE_NAME) &&
2390 !memcmp(data->d_buf + name_off, SDT_NOTE_NAME,
2391 sizeof(SDT_NOTE_NAME))) {
2392 /* Check the type of the note */
2393 if (nhdr.n_type != SDT_NOTE_TYPE)
2396 ret = populate_sdt_note(&elf, ((data->d_buf) + desc_off),
2397 nhdr.n_descsz, sdt_notes);
2402 if (list_empty(sdt_notes))
2410 * get_sdt_note_list : Wrapper to construct a list of sdt notes
2411 * @head : empty list_head
2412 * @target : file to find SDT notes from
2414 * This opens the file, initializes
2415 * the ELF and then calls construct_sdt_notes_list.
2417 int get_sdt_note_list(struct list_head *head, const char *target)
2422 fd = open(target, O_RDONLY);
2426 elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
2431 ret = construct_sdt_notes_list(elf, head);
2439 * cleanup_sdt_note_list : free the sdt notes' list
2440 * @sdt_notes: sdt notes' list
2442 * Free up the SDT notes in @sdt_notes.
2443 * Returns the number of SDT notes free'd.
2445 int cleanup_sdt_note_list(struct list_head *sdt_notes)
2447 struct sdt_note *tmp, *pos;
2450 list_for_each_entry_safe(pos, tmp, sdt_notes, note_list) {
2451 list_del_init(&pos->note_list);
2454 zfree(&pos->provider);
2462 * sdt_notes__get_count: Counts the number of sdt events
2463 * @start: list_head to sdt_notes list
2465 * Returns the number of SDT notes in a list
2467 int sdt_notes__get_count(struct list_head *start)
2469 struct sdt_note *sdt_ptr;
2472 list_for_each_entry(sdt_ptr, start, note_list)
2478 void symbol__elf_init(void)
2480 elf_version(EV_CURRENT);