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 int elf_read_program_header(Elf *elf, u64 vaddr, GElf_Phdr *phdr)
241 if (elf_getphdrnum(elf, &phdrnum))
244 for (i = 0; i < phdrnum; i++) {
245 if (gelf_getphdr(elf, i, phdr) == NULL)
248 if (phdr->p_type != PT_LOAD)
251 sz = max(phdr->p_memsz, phdr->p_filesz);
255 if (vaddr >= phdr->p_vaddr && (vaddr < phdr->p_vaddr + sz))
259 /* Not found any valid program header */
263 static bool want_demangle(bool is_kernel_sym)
265 return is_kernel_sym ? symbol_conf.demangle_kernel : symbol_conf.demangle;
268 static char *demangle_sym(struct dso *dso, int kmodule, const char *elf_name)
270 int demangle_flags = verbose > 0 ? (DMGL_PARAMS | DMGL_ANSI) : DMGL_NO_OPTS;
271 char *demangled = NULL;
274 * We need to figure out if the object was created from C++ sources
275 * DWARF DW_compile_unit has this, but we don't always have access
278 if (!want_demangle(dso->kernel || kmodule))
281 demangled = bfd_demangle(NULL, elf_name, demangle_flags);
282 if (demangled == NULL) {
283 demangled = ocaml_demangle_sym(elf_name);
284 if (demangled == NULL) {
285 demangled = java_demangle_sym(elf_name, JAVA_DEMANGLE_NORET);
288 else if (rust_is_mangled(demangled))
290 * Input to Rust demangling is the BFD-demangled
291 * name which it Rust-demangles in place.
293 rust_demangle_sym(demangled);
298 #define elf_section__for_each_rel(reldata, pos, pos_mem, idx, nr_entries) \
299 for (idx = 0, pos = gelf_getrel(reldata, 0, &pos_mem); \
301 ++idx, pos = gelf_getrel(reldata, idx, &pos_mem))
303 #define elf_section__for_each_rela(reldata, pos, pos_mem, idx, nr_entries) \
304 for (idx = 0, pos = gelf_getrela(reldata, 0, &pos_mem); \
306 ++idx, pos = gelf_getrela(reldata, idx, &pos_mem))
309 * We need to check if we have a .dynsym, so that we can handle the
310 * .plt, synthesizing its symbols, that aren't on the symtabs (be it
311 * .dynsym or .symtab).
312 * And always look at the original dso, not at debuginfo packages, that
313 * have the PLT data stripped out (shdr_rel_plt.sh_type == SHT_NOBITS).
315 int dso__synthesize_plt_symbols(struct dso *dso, struct symsrc *ss)
317 uint32_t nr_rel_entries, idx;
319 u64 plt_offset, plt_header_size, plt_entry_size;
322 GElf_Shdr shdr_rel_plt, shdr_dynsym;
323 Elf_Data *reldata, *syms, *symstrs;
324 Elf_Scn *scn_plt_rel, *scn_symstrs, *scn_dynsym;
327 char sympltname[1024];
329 int nr = 0, symidx, err = 0;
337 scn_dynsym = ss->dynsym;
338 shdr_dynsym = ss->dynshdr;
339 dynsym_idx = ss->dynsym_idx;
341 if (scn_dynsym == NULL)
344 scn_plt_rel = elf_section_by_name(elf, &ehdr, &shdr_rel_plt,
346 if (scn_plt_rel == NULL) {
347 scn_plt_rel = elf_section_by_name(elf, &ehdr, &shdr_rel_plt,
349 if (scn_plt_rel == NULL)
355 if (shdr_rel_plt.sh_link != dynsym_idx)
358 if (elf_section_by_name(elf, &ehdr, &shdr_plt, ".plt", NULL) == NULL)
362 * Fetch the relocation section to find the idxes to the GOT
363 * and the symbols in the .dynsym they refer to.
365 reldata = elf_getdata(scn_plt_rel, NULL);
369 syms = elf_getdata(scn_dynsym, NULL);
373 scn_symstrs = elf_getscn(elf, shdr_dynsym.sh_link);
374 if (scn_symstrs == NULL)
377 symstrs = elf_getdata(scn_symstrs, NULL);
381 if (symstrs->d_size == 0)
384 nr_rel_entries = shdr_rel_plt.sh_size / shdr_rel_plt.sh_entsize;
385 plt_offset = shdr_plt.sh_offset;
386 switch (ehdr.e_machine) {
388 plt_header_size = 20;
393 plt_header_size = 32;
398 plt_header_size = 48;
403 plt_header_size = 128;
407 default: /* FIXME: s390/alpha/mips/parisc/poperpc/sh/xtensa need to be checked */
408 plt_header_size = shdr_plt.sh_entsize;
409 plt_entry_size = shdr_plt.sh_entsize;
412 plt_offset += plt_header_size;
414 if (shdr_rel_plt.sh_type == SHT_RELA) {
415 GElf_Rela pos_mem, *pos;
417 elf_section__for_each_rela(reldata, pos, pos_mem, idx,
419 const char *elf_name = NULL;
420 char *demangled = NULL;
421 symidx = GELF_R_SYM(pos->r_info);
422 gelf_getsym(syms, symidx, &sym);
424 elf_name = elf_sym__name(&sym, symstrs);
425 demangled = demangle_sym(dso, 0, elf_name);
426 if (demangled != NULL)
427 elf_name = demangled;
428 snprintf(sympltname, sizeof(sympltname),
432 f = symbol__new(plt_offset, plt_entry_size,
433 STB_GLOBAL, STT_FUNC, sympltname);
437 plt_offset += plt_entry_size;
438 symbols__insert(&dso->symbols, f);
441 } else if (shdr_rel_plt.sh_type == SHT_REL) {
442 GElf_Rel pos_mem, *pos;
443 elf_section__for_each_rel(reldata, pos, pos_mem, idx,
445 const char *elf_name = NULL;
446 char *demangled = NULL;
447 symidx = GELF_R_SYM(pos->r_info);
448 gelf_getsym(syms, symidx, &sym);
450 elf_name = elf_sym__name(&sym, symstrs);
451 demangled = demangle_sym(dso, 0, elf_name);
452 if (demangled != NULL)
453 elf_name = demangled;
454 snprintf(sympltname, sizeof(sympltname),
458 f = symbol__new(plt_offset, plt_entry_size,
459 STB_GLOBAL, STT_FUNC, sympltname);
463 plt_offset += plt_entry_size;
464 symbols__insert(&dso->symbols, f);
473 pr_debug("%s: problems reading %s PLT info.\n",
474 __func__, dso->long_name);
478 char *dso__demangle_sym(struct dso *dso, int kmodule, const char *elf_name)
480 return demangle_sym(dso, kmodule, elf_name);
484 * Align offset to 4 bytes as needed for note name and descriptor data.
486 #define NOTE_ALIGN(n) (((n) + 3) & -4U)
488 static int elf_read_build_id(Elf *elf, void *bf, size_t size)
498 if (size < BUILD_ID_SIZE)
505 if (gelf_getehdr(elf, &ehdr) == NULL) {
506 pr_err("%s: cannot get elf header.\n", __func__);
511 * Check following sections for notes:
512 * '.note.gnu.build-id'
514 * '.note' (VDSO specific)
517 sec = elf_section_by_name(elf, &ehdr, &shdr,
518 ".note.gnu.build-id", NULL);
522 sec = elf_section_by_name(elf, &ehdr, &shdr,
527 sec = elf_section_by_name(elf, &ehdr, &shdr,
536 data = elf_getdata(sec, NULL);
541 while (ptr < (data->d_buf + data->d_size)) {
542 GElf_Nhdr *nhdr = ptr;
543 size_t namesz = NOTE_ALIGN(nhdr->n_namesz),
544 descsz = NOTE_ALIGN(nhdr->n_descsz);
547 ptr += sizeof(*nhdr);
550 if (nhdr->n_type == NT_GNU_BUILD_ID &&
551 nhdr->n_namesz == sizeof("GNU")) {
552 if (memcmp(name, "GNU", sizeof("GNU")) == 0) {
553 size_t sz = min(size, descsz);
555 memset(bf + sz, 0, size - sz);
567 #ifdef HAVE_LIBBFD_BUILDID_SUPPORT
569 static int read_build_id(const char *filename, struct build_id *bid)
571 size_t size = sizeof(bid->data);
575 abfd = bfd_openr(filename, NULL);
579 if (!bfd_check_format(abfd, bfd_object)) {
580 pr_debug2("%s: cannot read %s bfd file.\n", __func__, filename);
584 if (!abfd->build_id || abfd->build_id->size > size)
587 memcpy(bid->data, abfd->build_id->data, abfd->build_id->size);
588 memset(bid->data + abfd->build_id->size, 0, size - abfd->build_id->size);
589 err = bid->size = abfd->build_id->size;
596 #else // HAVE_LIBBFD_BUILDID_SUPPORT
598 static int read_build_id(const char *filename, struct build_id *bid)
600 size_t size = sizeof(bid->data);
604 if (size < BUILD_ID_SIZE)
607 fd = open(filename, O_RDONLY);
611 elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
613 pr_debug2("%s: cannot read %s ELF file.\n", __func__, filename);
617 err = elf_read_build_id(elf, bid->data, size);
628 #endif // HAVE_LIBBFD_BUILDID_SUPPORT
630 int filename__read_build_id(const char *filename, struct build_id *bid)
632 struct kmod_path m = { .name = NULL, };
639 err = kmod_path__parse(&m, filename);
646 fd = filename__decompress(filename, path, sizeof(path), m.comp, &error);
648 pr_debug("Failed to decompress (error %d) %s\n",
656 err = read_build_id(filename, bid);
663 int sysfs__read_build_id(const char *filename, struct build_id *bid)
665 size_t size = sizeof(bid->data);
668 fd = open(filename, O_RDONLY);
675 size_t namesz, descsz;
677 if (read(fd, &nhdr, sizeof(nhdr)) != sizeof(nhdr))
680 namesz = NOTE_ALIGN(nhdr.n_namesz);
681 descsz = NOTE_ALIGN(nhdr.n_descsz);
682 if (nhdr.n_type == NT_GNU_BUILD_ID &&
683 nhdr.n_namesz == sizeof("GNU")) {
684 if (read(fd, bf, namesz) != (ssize_t)namesz)
686 if (memcmp(bf, "GNU", sizeof("GNU")) == 0) {
687 size_t sz = min(descsz, size);
688 if (read(fd, bid->data, sz) == (ssize_t)sz) {
689 memset(bid->data + sz, 0, size - sz);
694 } else if (read(fd, bf, descsz) != (ssize_t)descsz)
697 int n = namesz + descsz;
699 if (n > (int)sizeof(bf)) {
701 pr_debug("%s: truncating reading of build id in sysfs file %s: n_namesz=%u, n_descsz=%u.\n",
702 __func__, filename, nhdr.n_namesz, nhdr.n_descsz);
704 if (read(fd, bf, n) != n)
713 #ifdef HAVE_LIBBFD_SUPPORT
715 int filename__read_debuglink(const char *filename, char *debuglink,
722 abfd = bfd_openr(filename, NULL);
726 if (!bfd_check_format(abfd, bfd_object)) {
727 pr_debug2("%s: cannot read %s bfd file.\n", __func__, filename);
731 section = bfd_get_section_by_name(abfd, ".gnu_debuglink");
735 if (section->size > size)
738 if (!bfd_get_section_contents(abfd, section, debuglink, 0,
751 int filename__read_debuglink(const char *filename, char *debuglink,
762 fd = open(filename, O_RDONLY);
766 elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
768 pr_debug2("%s: cannot read %s ELF file.\n", __func__, filename);
776 if (gelf_getehdr(elf, &ehdr) == NULL) {
777 pr_err("%s: cannot get elf header.\n", __func__);
781 sec = elf_section_by_name(elf, &ehdr, &shdr,
782 ".gnu_debuglink", NULL);
786 data = elf_getdata(sec, NULL);
790 /* the start of this section is a zero-terminated string */
791 strncpy(debuglink, data->d_buf, size);
805 static int dso__swap_init(struct dso *dso, unsigned char eidata)
807 static unsigned int const endian = 1;
809 dso->needs_swap = DSO_SWAP__NO;
813 /* We are big endian, DSO is little endian. */
814 if (*(unsigned char const *)&endian != 1)
815 dso->needs_swap = DSO_SWAP__YES;
819 /* We are little endian, DSO is big endian. */
820 if (*(unsigned char const *)&endian != 0)
821 dso->needs_swap = DSO_SWAP__YES;
825 pr_err("unrecognized DSO data encoding %d\n", eidata);
832 bool symsrc__possibly_runtime(struct symsrc *ss)
834 return ss->dynsym || ss->opdsec;
837 bool symsrc__has_symtab(struct symsrc *ss)
839 return ss->symtab != NULL;
842 void symsrc__destroy(struct symsrc *ss)
849 bool elf__needs_adjust_symbols(GElf_Ehdr ehdr)
852 * Usually vmlinux is an ELF file with type ET_EXEC for most
853 * architectures; except Arm64 kernel is linked with option
854 * '-share', so need to check type ET_DYN.
856 return ehdr.e_type == ET_EXEC || ehdr.e_type == ET_REL ||
857 ehdr.e_type == ET_DYN;
860 int symsrc__init(struct symsrc *ss, struct dso *dso, const char *name,
861 enum dso_binary_type type)
867 if (dso__needs_decompress(dso)) {
868 fd = dso__decompress_kmodule_fd(dso, name);
872 type = dso->symtab_type;
874 fd = open(name, O_RDONLY);
876 dso->load_errno = errno;
881 elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
883 pr_debug("%s: cannot read %s ELF file.\n", __func__, name);
884 dso->load_errno = DSO_LOAD_ERRNO__INVALID_ELF;
888 if (gelf_getehdr(elf, &ehdr) == NULL) {
889 dso->load_errno = DSO_LOAD_ERRNO__INVALID_ELF;
890 pr_debug("%s: cannot get elf header.\n", __func__);
894 if (dso__swap_init(dso, ehdr.e_ident[EI_DATA])) {
895 dso->load_errno = DSO_LOAD_ERRNO__INTERNAL_ERROR;
899 /* Always reject images with a mismatched build-id: */
900 if (dso->has_build_id && !symbol_conf.ignore_vmlinux_buildid) {
901 u8 build_id[BUILD_ID_SIZE];
905 size = elf_read_build_id(elf, build_id, BUILD_ID_SIZE);
907 dso->load_errno = DSO_LOAD_ERRNO__CANNOT_READ_BUILDID;
911 build_id__init(&bid, build_id, size);
912 if (!dso__build_id_equal(dso, &bid)) {
913 pr_debug("%s: build id mismatch for %s.\n", __func__, name);
914 dso->load_errno = DSO_LOAD_ERRNO__MISMATCHING_BUILDID;
919 ss->is_64_bit = (gelf_getclass(elf) == ELFCLASS64);
921 ss->symtab = elf_section_by_name(elf, &ehdr, &ss->symshdr, ".symtab",
923 if (ss->symshdr.sh_type != SHT_SYMTAB)
927 ss->dynsym = elf_section_by_name(elf, &ehdr, &ss->dynshdr, ".dynsym",
929 if (ss->dynshdr.sh_type != SHT_DYNSYM)
933 ss->opdsec = elf_section_by_name(elf, &ehdr, &ss->opdshdr, ".opd",
935 if (ss->opdshdr.sh_type != SHT_PROGBITS)
938 if (dso->kernel == DSO_SPACE__USER)
939 ss->adjust_symbols = true;
941 ss->adjust_symbols = elf__needs_adjust_symbols(ehdr);
943 ss->name = strdup(name);
945 dso->load_errno = errno;
964 * ref_reloc_sym_not_found - has kernel relocation symbol been found.
965 * @kmap: kernel maps and relocation reference symbol
967 * This function returns %true if we are dealing with the kernel maps and the
968 * relocation reference symbol has not yet been found. Otherwise %false is
971 static bool ref_reloc_sym_not_found(struct kmap *kmap)
973 return kmap && kmap->ref_reloc_sym && kmap->ref_reloc_sym->name &&
974 !kmap->ref_reloc_sym->unrelocated_addr;
978 * ref_reloc - kernel relocation offset.
979 * @kmap: kernel maps and relocation reference symbol
981 * This function returns the offset of kernel addresses as determined by using
982 * the relocation reference symbol i.e. if the kernel has not been relocated
983 * then the return value is zero.
985 static u64 ref_reloc(struct kmap *kmap)
987 if (kmap && kmap->ref_reloc_sym &&
988 kmap->ref_reloc_sym->unrelocated_addr)
989 return kmap->ref_reloc_sym->addr -
990 kmap->ref_reloc_sym->unrelocated_addr;
994 void __weak arch__sym_update(struct symbol *s __maybe_unused,
995 GElf_Sym *sym __maybe_unused) { }
997 static int dso__process_kernel_symbol(struct dso *dso, struct map *map,
998 GElf_Sym *sym, GElf_Shdr *shdr,
999 struct maps *kmaps, struct kmap *kmap,
1000 struct dso **curr_dsop, struct map **curr_mapp,
1001 const char *section_name,
1002 bool adjust_kernel_syms, bool kmodule, bool *remap_kernel)
1004 struct dso *curr_dso = *curr_dsop;
1005 struct map *curr_map;
1006 char dso_name[PATH_MAX];
1008 /* Adjust symbol to map to file offset */
1009 if (adjust_kernel_syms)
1010 sym->st_value -= shdr->sh_addr - shdr->sh_offset;
1012 if (strcmp(section_name, (curr_dso->short_name + dso->short_name_len)) == 0)
1015 if (strcmp(section_name, ".text") == 0) {
1017 * The initial kernel mapping is based on
1018 * kallsyms and identity maps. Overwrite it to
1019 * map to the kernel dso.
1021 if (*remap_kernel && dso->kernel && !kmodule) {
1022 *remap_kernel = false;
1023 map->start = shdr->sh_addr + ref_reloc(kmap);
1024 map->end = map->start + shdr->sh_size;
1025 map->pgoff = shdr->sh_offset;
1026 map->map_ip = map__map_ip;
1027 map->unmap_ip = map__unmap_ip;
1028 /* Ensure maps are correctly ordered */
1031 maps__remove(kmaps, map);
1032 maps__insert(kmaps, map);
1038 * The initial module mapping is based on
1039 * /proc/modules mapped to offset zero.
1040 * Overwrite it to map to the module dso.
1042 if (*remap_kernel && kmodule) {
1043 *remap_kernel = false;
1044 map->pgoff = shdr->sh_offset;
1055 snprintf(dso_name, sizeof(dso_name), "%s%s", dso->short_name, section_name);
1057 curr_map = maps__find_by_name(kmaps, dso_name);
1058 if (curr_map == NULL) {
1059 u64 start = sym->st_value;
1062 start += map->start + shdr->sh_offset;
1064 curr_dso = dso__new(dso_name);
1065 if (curr_dso == NULL)
1067 curr_dso->kernel = dso->kernel;
1068 curr_dso->long_name = dso->long_name;
1069 curr_dso->long_name_len = dso->long_name_len;
1070 curr_map = map__new2(start, curr_dso);
1072 if (curr_map == NULL)
1075 if (curr_dso->kernel)
1076 map__kmap(curr_map)->kmaps = kmaps;
1078 if (adjust_kernel_syms) {
1079 curr_map->start = shdr->sh_addr + ref_reloc(kmap);
1080 curr_map->end = curr_map->start + shdr->sh_size;
1081 curr_map->pgoff = shdr->sh_offset;
1083 curr_map->map_ip = curr_map->unmap_ip = identity__map_ip;
1085 curr_dso->symtab_type = dso->symtab_type;
1086 maps__insert(kmaps, curr_map);
1088 * Add it before we drop the reference to curr_map, i.e. while
1089 * we still are sure to have a reference to this DSO via
1092 dsos__add(&kmaps->machine->dsos, curr_dso);
1093 /* kmaps already got it */
1095 dso__set_loaded(curr_dso);
1096 *curr_mapp = curr_map;
1097 *curr_dsop = curr_dso;
1099 *curr_dsop = curr_map->dso;
1105 dso__load_sym_internal(struct dso *dso, struct map *map, struct symsrc *syms_ss,
1106 struct symsrc *runtime_ss, int kmodule, int dynsym)
1108 struct kmap *kmap = dso->kernel ? map__kmap(map) : NULL;
1109 struct maps *kmaps = kmap ? map__kmaps(map) : NULL;
1110 struct map *curr_map = map;
1111 struct dso *curr_dso = dso;
1112 Elf_Data *symstrs, *secstrs, *secstrs_run, *secstrs_sym;
1119 Elf_Data *syms, *opddata = NULL;
1121 Elf_Scn *sec, *sec_strndx;
1124 bool remap_kernel = false, adjust_kernel_syms = false;
1130 ehdr = syms_ss->ehdr;
1132 sec = syms_ss->dynsym;
1133 shdr = syms_ss->dynshdr;
1135 sec = syms_ss->symtab;
1136 shdr = syms_ss->symshdr;
1139 if (elf_section_by_name(runtime_ss->elf, &runtime_ss->ehdr, &tshdr,
1141 dso->text_offset = tshdr.sh_addr - tshdr.sh_offset;
1143 if (runtime_ss->opdsec)
1144 opddata = elf_rawdata(runtime_ss->opdsec, NULL);
1146 syms = elf_getdata(sec, NULL);
1150 sec = elf_getscn(elf, shdr.sh_link);
1154 symstrs = elf_getdata(sec, NULL);
1155 if (symstrs == NULL)
1158 sec_strndx = elf_getscn(runtime_ss->elf, runtime_ss->ehdr.e_shstrndx);
1159 if (sec_strndx == NULL)
1162 secstrs_run = elf_getdata(sec_strndx, NULL);
1163 if (secstrs_run == NULL)
1166 sec_strndx = elf_getscn(elf, ehdr.e_shstrndx);
1167 if (sec_strndx == NULL)
1170 secstrs_sym = elf_getdata(sec_strndx, NULL);
1171 if (secstrs_sym == NULL)
1174 nr_syms = shdr.sh_size / shdr.sh_entsize;
1176 memset(&sym, 0, sizeof(sym));
1179 * The kernel relocation symbol is needed in advance in order to adjust
1180 * kernel maps correctly.
1182 if (ref_reloc_sym_not_found(kmap)) {
1183 elf_symtab__for_each_symbol(syms, nr_syms, idx, sym) {
1184 const char *elf_name = elf_sym__name(&sym, symstrs);
1186 if (strcmp(elf_name, kmap->ref_reloc_sym->name))
1188 kmap->ref_reloc_sym->unrelocated_addr = sym.st_value;
1189 map->reloc = kmap->ref_reloc_sym->addr -
1190 kmap->ref_reloc_sym->unrelocated_addr;
1196 * Handle any relocation of vdso necessary because older kernels
1197 * attempted to prelink vdso to its virtual address.
1199 if (dso__is_vdso(dso))
1200 map->reloc = map->start - dso->text_offset;
1202 dso->adjust_symbols = runtime_ss->adjust_symbols || ref_reloc(kmap);
1204 * Initial kernel and module mappings do not map to the dso.
1208 remap_kernel = true;
1209 adjust_kernel_syms = dso->adjust_symbols;
1211 elf_symtab__for_each_symbol(syms, nr_syms, idx, sym) {
1213 const char *elf_name = elf_sym__name(&sym, symstrs);
1214 char *demangled = NULL;
1215 int is_label = elf_sym__is_label(&sym);
1216 const char *section_name;
1217 bool used_opd = false;
1219 if (!is_label && !elf_sym__filter(&sym))
1222 /* Reject ARM ELF "mapping symbols": these aren't unique and
1223 * don't identify functions, so will confuse the profile
1225 if (ehdr.e_machine == EM_ARM || ehdr.e_machine == EM_AARCH64) {
1226 if (elf_name[0] == '$' && strchr("adtx", elf_name[1])
1227 && (elf_name[2] == '\0' || elf_name[2] == '.'))
1231 if (runtime_ss->opdsec && sym.st_shndx == runtime_ss->opdidx) {
1232 u32 offset = sym.st_value - syms_ss->opdshdr.sh_addr;
1233 u64 *opd = opddata->d_buf + offset;
1234 sym.st_value = DSO__SWAP(dso, u64, *opd);
1235 sym.st_shndx = elf_addr_to_index(runtime_ss->elf,
1241 * When loading symbols in a data mapping, ABS symbols (which
1242 * has a value of SHN_ABS in its st_shndx) failed at
1243 * elf_getscn(). And it marks the loading as a failure so
1244 * already loaded symbols cannot be fixed up.
1246 * I'm not sure what should be done. Just ignore them for now.
1249 if (sym.st_shndx == SHN_ABS)
1252 sec = elf_getscn(syms_ss->elf, sym.st_shndx);
1256 gelf_getshdr(sec, &shdr);
1259 * If the attribute bit SHF_ALLOC is not set, the section
1260 * doesn't occupy memory during process execution.
1261 * E.g. ".gnu.warning.*" section is used by linker to generate
1262 * warnings when calling deprecated functions, the symbols in
1263 * the section aren't loaded to memory during process execution,
1266 if (!(shdr.sh_flags & SHF_ALLOC))
1269 secstrs = secstrs_sym;
1272 * We have to fallback to runtime when syms' section header has
1273 * NOBITS set. NOBITS results in file offset (sh_offset) not
1274 * being incremented. So sh_offset used below has different
1275 * values for syms (invalid) and runtime (valid).
1277 if (shdr.sh_type == SHT_NOBITS) {
1278 sec = elf_getscn(runtime_ss->elf, sym.st_shndx);
1282 gelf_getshdr(sec, &shdr);
1283 secstrs = secstrs_run;
1286 if (is_label && !elf_sec__filter(&shdr, secstrs))
1289 section_name = elf_sec__name(&shdr, secstrs);
1291 /* On ARM, symbols for thumb functions have 1 added to
1292 * the symbol address as a flag - remove it */
1293 if ((ehdr.e_machine == EM_ARM) &&
1294 (GELF_ST_TYPE(sym.st_info) == STT_FUNC) &&
1299 if (dso__process_kernel_symbol(dso, map, &sym, &shdr, kmaps, kmap, &curr_dso, &curr_map,
1300 section_name, adjust_kernel_syms, kmodule, &remap_kernel))
1302 } else if ((used_opd && runtime_ss->adjust_symbols) ||
1303 (!used_opd && syms_ss->adjust_symbols)) {
1306 if (elf_read_program_header(syms_ss->elf,
1307 (u64)sym.st_value, &phdr)) {
1308 pr_debug4("%s: failed to find program header for "
1309 "symbol: %s st_value: %#" PRIx64 "\n",
1310 __func__, elf_name, (u64)sym.st_value);
1311 pr_debug4("%s: adjusting symbol: st_value: %#" PRIx64 " "
1312 "sh_addr: %#" PRIx64 " sh_offset: %#" PRIx64 "\n",
1313 __func__, (u64)sym.st_value, (u64)shdr.sh_addr,
1314 (u64)shdr.sh_offset);
1316 * Fail to find program header, let's rollback
1317 * to use shdr.sh_addr and shdr.sh_offset to
1318 * calibrate symbol's file address, though this
1319 * is not necessary for normal C ELF file, we
1320 * still need to handle java JIT symbols in this
1323 sym.st_value -= shdr.sh_addr - shdr.sh_offset;
1325 pr_debug4("%s: adjusting symbol: st_value: %#" PRIx64 " "
1326 "p_vaddr: %#" PRIx64 " p_offset: %#" PRIx64 "\n",
1327 __func__, (u64)sym.st_value, (u64)phdr.p_vaddr,
1328 (u64)phdr.p_offset);
1329 sym.st_value -= phdr.p_vaddr - phdr.p_offset;
1333 demangled = demangle_sym(dso, kmodule, elf_name);
1334 if (demangled != NULL)
1335 elf_name = demangled;
1337 f = symbol__new(sym.st_value, sym.st_size,
1338 GELF_ST_BIND(sym.st_info),
1339 GELF_ST_TYPE(sym.st_info), elf_name);
1344 arch__sym_update(f, &sym);
1346 __symbols__insert(&curr_dso->symbols, f, dso->kernel);
1351 * For misannotated, zeroed, ASM function sizes.
1354 symbols__fixup_end(&dso->symbols, false);
1355 symbols__fixup_duplicate(&dso->symbols);
1358 * We need to fixup this here too because we create new
1359 * maps here, for things like vsyscall sections.
1361 maps__fixup_end(kmaps);
1369 int dso__load_sym(struct dso *dso, struct map *map, struct symsrc *syms_ss,
1370 struct symsrc *runtime_ss, int kmodule)
1375 dso->symtab_type = syms_ss->type;
1376 dso->is_64_bit = syms_ss->is_64_bit;
1377 dso->rel = syms_ss->ehdr.e_type == ET_REL;
1380 * Modules may already have symbols from kallsyms, but those symbols
1381 * have the wrong values for the dso maps, so remove them.
1383 if (kmodule && syms_ss->symtab)
1384 symbols__delete(&dso->symbols);
1386 if (!syms_ss->symtab) {
1388 * If the vmlinux is stripped, fail so we will fall back
1389 * to using kallsyms. The vmlinux runtime symbols aren't
1395 err = dso__load_sym_internal(dso, map, syms_ss, runtime_ss,
1402 if (syms_ss->dynsym) {
1403 err = dso__load_sym_internal(dso, map, syms_ss, runtime_ss,
1413 static int elf_read_maps(Elf *elf, bool exe, mapfn_t mapfn, void *data)
1420 if (elf_getphdrnum(elf, &phdrnum))
1423 for (i = 0; i < phdrnum; i++) {
1424 if (gelf_getphdr(elf, i, &phdr) == NULL)
1426 if (phdr.p_type != PT_LOAD)
1429 if (!(phdr.p_flags & PF_X))
1432 if (!(phdr.p_flags & PF_R))
1435 sz = min(phdr.p_memsz, phdr.p_filesz);
1438 err = mapfn(phdr.p_vaddr, sz, phdr.p_offset, data);
1445 int file__read_maps(int fd, bool exe, mapfn_t mapfn, void *data,
1451 elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
1456 *is_64_bit = (gelf_getclass(elf) == ELFCLASS64);
1458 err = elf_read_maps(elf, exe, mapfn, data);
1464 enum dso_type dso__type_fd(int fd)
1466 enum dso_type dso_type = DSO__TYPE_UNKNOWN;
1471 elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
1476 if (ek != ELF_K_ELF)
1479 if (gelf_getclass(elf) == ELFCLASS64) {
1480 dso_type = DSO__TYPE_64BIT;
1484 if (gelf_getehdr(elf, &ehdr) == NULL)
1487 if (ehdr.e_machine == EM_X86_64)
1488 dso_type = DSO__TYPE_X32BIT;
1490 dso_type = DSO__TYPE_32BIT;
1497 static int copy_bytes(int from, off_t from_offs, int to, off_t to_offs, u64 len)
1502 char *buf = malloc(page_size);
1507 if (lseek(to, to_offs, SEEK_SET) != to_offs)
1510 if (lseek(from, from_offs, SEEK_SET) != from_offs)
1517 /* Use read because mmap won't work on proc files */
1518 r = read(from, buf, n);
1524 r = write(to, buf, n);
1545 static int kcore__open(struct kcore *kcore, const char *filename)
1549 kcore->fd = open(filename, O_RDONLY);
1550 if (kcore->fd == -1)
1553 kcore->elf = elf_begin(kcore->fd, ELF_C_READ, NULL);
1557 kcore->elfclass = gelf_getclass(kcore->elf);
1558 if (kcore->elfclass == ELFCLASSNONE)
1561 ehdr = gelf_getehdr(kcore->elf, &kcore->ehdr);
1568 elf_end(kcore->elf);
1574 static int kcore__init(struct kcore *kcore, char *filename, int elfclass,
1577 kcore->elfclass = elfclass;
1580 kcore->fd = mkstemp(filename);
1582 kcore->fd = open(filename, O_WRONLY | O_CREAT | O_EXCL, 0400);
1583 if (kcore->fd == -1)
1586 kcore->elf = elf_begin(kcore->fd, ELF_C_WRITE, NULL);
1590 if (!gelf_newehdr(kcore->elf, elfclass))
1593 memset(&kcore->ehdr, 0, sizeof(GElf_Ehdr));
1598 elf_end(kcore->elf);
1605 static void kcore__close(struct kcore *kcore)
1607 elf_end(kcore->elf);
1611 static int kcore__copy_hdr(struct kcore *from, struct kcore *to, size_t count)
1613 GElf_Ehdr *ehdr = &to->ehdr;
1614 GElf_Ehdr *kehdr = &from->ehdr;
1616 memcpy(ehdr->e_ident, kehdr->e_ident, EI_NIDENT);
1617 ehdr->e_type = kehdr->e_type;
1618 ehdr->e_machine = kehdr->e_machine;
1619 ehdr->e_version = kehdr->e_version;
1622 ehdr->e_flags = kehdr->e_flags;
1623 ehdr->e_phnum = count;
1624 ehdr->e_shentsize = 0;
1626 ehdr->e_shstrndx = 0;
1628 if (from->elfclass == ELFCLASS32) {
1629 ehdr->e_phoff = sizeof(Elf32_Ehdr);
1630 ehdr->e_ehsize = sizeof(Elf32_Ehdr);
1631 ehdr->e_phentsize = sizeof(Elf32_Phdr);
1633 ehdr->e_phoff = sizeof(Elf64_Ehdr);
1634 ehdr->e_ehsize = sizeof(Elf64_Ehdr);
1635 ehdr->e_phentsize = sizeof(Elf64_Phdr);
1638 if (!gelf_update_ehdr(to->elf, ehdr))
1641 if (!gelf_newphdr(to->elf, count))
1647 static int kcore__add_phdr(struct kcore *kcore, int idx, off_t offset,
1652 .p_flags = PF_R | PF_W | PF_X,
1658 .p_align = page_size,
1661 if (!gelf_update_phdr(kcore->elf, idx, &phdr))
1667 static off_t kcore__write(struct kcore *kcore)
1669 return elf_update(kcore->elf, ELF_C_WRITE);
1677 struct list_head node;
1678 struct phdr_data *remaps;
1683 struct list_head node;
1686 struct kcore_copy_info {
1692 u64 first_module_symbol;
1693 u64 last_module_symbol;
1695 struct list_head phdrs;
1696 struct list_head syms;
1699 #define kcore_copy__for_each_phdr(k, p) \
1700 list_for_each_entry((p), &(k)->phdrs, node)
1702 static struct phdr_data *phdr_data__new(u64 addr, u64 len, off_t offset)
1704 struct phdr_data *p = zalloc(sizeof(*p));
1715 static struct phdr_data *kcore_copy_info__addnew(struct kcore_copy_info *kci,
1719 struct phdr_data *p = phdr_data__new(addr, len, offset);
1722 list_add_tail(&p->node, &kci->phdrs);
1727 static void kcore_copy__free_phdrs(struct kcore_copy_info *kci)
1729 struct phdr_data *p, *tmp;
1731 list_for_each_entry_safe(p, tmp, &kci->phdrs, node) {
1732 list_del_init(&p->node);
1737 static struct sym_data *kcore_copy__new_sym(struct kcore_copy_info *kci,
1740 struct sym_data *s = zalloc(sizeof(*s));
1744 list_add_tail(&s->node, &kci->syms);
1750 static void kcore_copy__free_syms(struct kcore_copy_info *kci)
1752 struct sym_data *s, *tmp;
1754 list_for_each_entry_safe(s, tmp, &kci->syms, node) {
1755 list_del_init(&s->node);
1760 static int kcore_copy__process_kallsyms(void *arg, const char *name, char type,
1763 struct kcore_copy_info *kci = arg;
1765 if (!kallsyms__is_function(type))
1768 if (strchr(name, '[')) {
1769 if (!kci->first_module_symbol || start < kci->first_module_symbol)
1770 kci->first_module_symbol = start;
1771 if (start > kci->last_module_symbol)
1772 kci->last_module_symbol = start;
1776 if (!kci->first_symbol || start < kci->first_symbol)
1777 kci->first_symbol = start;
1779 if (!kci->last_symbol || start > kci->last_symbol)
1780 kci->last_symbol = start;
1782 if (!strcmp(name, "_stext")) {
1787 if (!strcmp(name, "_etext")) {
1792 if (is_entry_trampoline(name) && !kcore_copy__new_sym(kci, start))
1798 static int kcore_copy__parse_kallsyms(struct kcore_copy_info *kci,
1801 char kallsyms_filename[PATH_MAX];
1803 scnprintf(kallsyms_filename, PATH_MAX, "%s/kallsyms", dir);
1805 if (symbol__restricted_filename(kallsyms_filename, "/proc/kallsyms"))
1808 if (kallsyms__parse(kallsyms_filename, kci,
1809 kcore_copy__process_kallsyms) < 0)
1815 static int kcore_copy__process_modules(void *arg,
1816 const char *name __maybe_unused,
1817 u64 start, u64 size __maybe_unused)
1819 struct kcore_copy_info *kci = arg;
1821 if (!kci->first_module || start < kci->first_module)
1822 kci->first_module = start;
1827 static int kcore_copy__parse_modules(struct kcore_copy_info *kci,
1830 char modules_filename[PATH_MAX];
1832 scnprintf(modules_filename, PATH_MAX, "%s/modules", dir);
1834 if (symbol__restricted_filename(modules_filename, "/proc/modules"))
1837 if (modules__parse(modules_filename, kci,
1838 kcore_copy__process_modules) < 0)
1844 static int kcore_copy__map(struct kcore_copy_info *kci, u64 start, u64 end,
1845 u64 pgoff, u64 s, u64 e)
1849 if (s < start || s >= end)
1852 offset = (s - start) + pgoff;
1853 len = e < end ? e - s : end - s;
1855 return kcore_copy_info__addnew(kci, s, len, offset) ? 0 : -1;
1858 static int kcore_copy__read_map(u64 start, u64 len, u64 pgoff, void *data)
1860 struct kcore_copy_info *kci = data;
1861 u64 end = start + len;
1862 struct sym_data *sdat;
1864 if (kcore_copy__map(kci, start, end, pgoff, kci->stext, kci->etext))
1867 if (kcore_copy__map(kci, start, end, pgoff, kci->first_module,
1868 kci->last_module_symbol))
1871 list_for_each_entry(sdat, &kci->syms, node) {
1872 u64 s = round_down(sdat->addr, page_size);
1874 if (kcore_copy__map(kci, start, end, pgoff, s, s + len))
1881 static int kcore_copy__read_maps(struct kcore_copy_info *kci, Elf *elf)
1883 if (elf_read_maps(elf, true, kcore_copy__read_map, kci) < 0)
1889 static void kcore_copy__find_remaps(struct kcore_copy_info *kci)
1891 struct phdr_data *p, *k = NULL;
1897 /* Find phdr that corresponds to the kernel map (contains stext) */
1898 kcore_copy__for_each_phdr(kci, p) {
1899 u64 pend = p->addr + p->len - 1;
1901 if (p->addr <= kci->stext && pend >= kci->stext) {
1910 kend = k->offset + k->len;
1912 /* Find phdrs that remap the kernel */
1913 kcore_copy__for_each_phdr(kci, p) {
1914 u64 pend = p->offset + p->len;
1919 if (p->offset >= k->offset && pend <= kend)
1924 static void kcore_copy__layout(struct kcore_copy_info *kci)
1926 struct phdr_data *p;
1929 kcore_copy__find_remaps(kci);
1931 kcore_copy__for_each_phdr(kci, p) {
1939 kcore_copy__for_each_phdr(kci, p) {
1940 struct phdr_data *k = p->remaps;
1943 p->rel = p->offset - k->offset + k->rel;
1947 static int kcore_copy__calc_maps(struct kcore_copy_info *kci, const char *dir,
1950 if (kcore_copy__parse_kallsyms(kci, dir))
1953 if (kcore_copy__parse_modules(kci, dir))
1957 kci->stext = round_down(kci->stext, page_size);
1959 kci->stext = round_down(kci->first_symbol, page_size);
1962 kci->etext = round_up(kci->etext, page_size);
1963 } else if (kci->last_symbol) {
1964 kci->etext = round_up(kci->last_symbol, page_size);
1965 kci->etext += page_size;
1968 if (kci->first_module_symbol &&
1969 (!kci->first_module || kci->first_module_symbol < kci->first_module))
1970 kci->first_module = kci->first_module_symbol;
1972 kci->first_module = round_down(kci->first_module, page_size);
1974 if (kci->last_module_symbol) {
1975 kci->last_module_symbol = round_up(kci->last_module_symbol,
1977 kci->last_module_symbol += page_size;
1980 if (!kci->stext || !kci->etext)
1983 if (kci->first_module && !kci->last_module_symbol)
1986 if (kcore_copy__read_maps(kci, elf))
1989 kcore_copy__layout(kci);
1994 static int kcore_copy__copy_file(const char *from_dir, const char *to_dir,
1997 char from_filename[PATH_MAX];
1998 char to_filename[PATH_MAX];
2000 scnprintf(from_filename, PATH_MAX, "%s/%s", from_dir, name);
2001 scnprintf(to_filename, PATH_MAX, "%s/%s", to_dir, name);
2003 return copyfile_mode(from_filename, to_filename, 0400);
2006 static int kcore_copy__unlink(const char *dir, const char *name)
2008 char filename[PATH_MAX];
2010 scnprintf(filename, PATH_MAX, "%s/%s", dir, name);
2012 return unlink(filename);
2015 static int kcore_copy__compare_fds(int from, int to)
2023 buf_from = malloc(page_size);
2024 buf_to = malloc(page_size);
2025 if (!buf_from || !buf_to)
2029 /* Use read because mmap won't work on proc files */
2030 ret = read(from, buf_from, page_size);
2039 if (readn(to, buf_to, len) != (int)len)
2042 if (memcmp(buf_from, buf_to, len))
2053 static int kcore_copy__compare_files(const char *from_filename,
2054 const char *to_filename)
2056 int from, to, err = -1;
2058 from = open(from_filename, O_RDONLY);
2062 to = open(to_filename, O_RDONLY);
2064 goto out_close_from;
2066 err = kcore_copy__compare_fds(from, to);
2074 static int kcore_copy__compare_file(const char *from_dir, const char *to_dir,
2077 char from_filename[PATH_MAX];
2078 char to_filename[PATH_MAX];
2080 scnprintf(from_filename, PATH_MAX, "%s/%s", from_dir, name);
2081 scnprintf(to_filename, PATH_MAX, "%s/%s", to_dir, name);
2083 return kcore_copy__compare_files(from_filename, to_filename);
2087 * kcore_copy - copy kallsyms, modules and kcore from one directory to another.
2088 * @from_dir: from directory
2089 * @to_dir: to directory
2091 * This function copies kallsyms, modules and kcore files from one directory to
2092 * another. kallsyms and modules are copied entirely. Only code segments are
2093 * copied from kcore. It is assumed that two segments suffice: one for the
2094 * kernel proper and one for all the modules. The code segments are determined
2095 * from kallsyms and modules files. The kernel map starts at _stext or the
2096 * lowest function symbol, and ends at _etext or the highest function symbol.
2097 * The module map starts at the lowest module address and ends at the highest
2098 * module symbol. Start addresses are rounded down to the nearest page. End
2099 * addresses are rounded up to the nearest page. An extra page is added to the
2100 * highest kernel symbol and highest module symbol to, hopefully, encompass that
2101 * symbol too. Because it contains only code sections, the resulting kcore is
2102 * unusual. One significant peculiarity is that the mapping (start -> pgoff)
2103 * is not the same for the kernel map and the modules map. That happens because
2104 * the data is copied adjacently whereas the original kcore has gaps. Finally,
2105 * kallsyms file is compared with its copy to check that modules have not been
2106 * loaded or unloaded while the copies were taking place.
2108 * Return: %0 on success, %-1 on failure.
2110 int kcore_copy(const char *from_dir, const char *to_dir)
2113 struct kcore extract;
2114 int idx = 0, err = -1;
2116 struct kcore_copy_info kci = { .stext = 0, };
2117 char kcore_filename[PATH_MAX];
2118 char extract_filename[PATH_MAX];
2119 struct phdr_data *p;
2121 INIT_LIST_HEAD(&kci.phdrs);
2122 INIT_LIST_HEAD(&kci.syms);
2124 if (kcore_copy__copy_file(from_dir, to_dir, "kallsyms"))
2127 if (kcore_copy__copy_file(from_dir, to_dir, "modules"))
2128 goto out_unlink_kallsyms;
2130 scnprintf(kcore_filename, PATH_MAX, "%s/kcore", from_dir);
2131 scnprintf(extract_filename, PATH_MAX, "%s/kcore", to_dir);
2133 if (kcore__open(&kcore, kcore_filename))
2134 goto out_unlink_modules;
2136 if (kcore_copy__calc_maps(&kci, from_dir, kcore.elf))
2137 goto out_kcore_close;
2139 if (kcore__init(&extract, extract_filename, kcore.elfclass, false))
2140 goto out_kcore_close;
2142 if (kcore__copy_hdr(&kcore, &extract, kci.phnum))
2143 goto out_extract_close;
2145 offset = gelf_fsize(extract.elf, ELF_T_EHDR, 1, EV_CURRENT) +
2146 gelf_fsize(extract.elf, ELF_T_PHDR, kci.phnum, EV_CURRENT);
2147 offset = round_up(offset, page_size);
2149 kcore_copy__for_each_phdr(&kci, p) {
2150 off_t offs = p->rel + offset;
2152 if (kcore__add_phdr(&extract, idx++, offs, p->addr, p->len))
2153 goto out_extract_close;
2156 sz = kcore__write(&extract);
2157 if (sz < 0 || sz > offset)
2158 goto out_extract_close;
2160 kcore_copy__for_each_phdr(&kci, p) {
2161 off_t offs = p->rel + offset;
2165 if (copy_bytes(kcore.fd, p->offset, extract.fd, offs, p->len))
2166 goto out_extract_close;
2169 if (kcore_copy__compare_file(from_dir, to_dir, "kallsyms"))
2170 goto out_extract_close;
2175 kcore__close(&extract);
2177 unlink(extract_filename);
2179 kcore__close(&kcore);
2182 kcore_copy__unlink(to_dir, "modules");
2183 out_unlink_kallsyms:
2185 kcore_copy__unlink(to_dir, "kallsyms");
2187 kcore_copy__free_phdrs(&kci);
2188 kcore_copy__free_syms(&kci);
2193 int kcore_extract__create(struct kcore_extract *kce)
2196 struct kcore extract;
2198 int idx = 0, err = -1;
2199 off_t offset = page_size, sz;
2201 if (kcore__open(&kcore, kce->kcore_filename))
2204 strcpy(kce->extract_filename, PERF_KCORE_EXTRACT);
2205 if (kcore__init(&extract, kce->extract_filename, kcore.elfclass, true))
2206 goto out_kcore_close;
2208 if (kcore__copy_hdr(&kcore, &extract, count))
2209 goto out_extract_close;
2211 if (kcore__add_phdr(&extract, idx, offset, kce->addr, kce->len))
2212 goto out_extract_close;
2214 sz = kcore__write(&extract);
2215 if (sz < 0 || sz > offset)
2216 goto out_extract_close;
2218 if (copy_bytes(kcore.fd, kce->offs, extract.fd, offset, kce->len))
2219 goto out_extract_close;
2224 kcore__close(&extract);
2226 unlink(kce->extract_filename);
2228 kcore__close(&kcore);
2233 void kcore_extract__delete(struct kcore_extract *kce)
2235 unlink(kce->extract_filename);
2238 #ifdef HAVE_GELF_GETNOTE_SUPPORT
2240 static void sdt_adjust_loc(struct sdt_note *tmp, GElf_Addr base_off)
2246 tmp->addr.a32[SDT_NOTE_IDX_LOC] =
2247 tmp->addr.a32[SDT_NOTE_IDX_LOC] + base_off -
2248 tmp->addr.a32[SDT_NOTE_IDX_BASE];
2250 tmp->addr.a64[SDT_NOTE_IDX_LOC] =
2251 tmp->addr.a64[SDT_NOTE_IDX_LOC] + base_off -
2252 tmp->addr.a64[SDT_NOTE_IDX_BASE];
2255 static void sdt_adjust_refctr(struct sdt_note *tmp, GElf_Addr base_addr,
2261 if (tmp->bit32 && tmp->addr.a32[SDT_NOTE_IDX_REFCTR])
2262 tmp->addr.a32[SDT_NOTE_IDX_REFCTR] -= (base_addr - base_off);
2263 else if (tmp->addr.a64[SDT_NOTE_IDX_REFCTR])
2264 tmp->addr.a64[SDT_NOTE_IDX_REFCTR] -= (base_addr - base_off);
2268 * populate_sdt_note : Parse raw data and identify SDT note
2269 * @elf: elf of the opened file
2270 * @data: raw data of a section with description offset applied
2271 * @len: note description size
2272 * @type: type of the note
2273 * @sdt_notes: List to add the SDT note
2275 * Responsible for parsing the @data in section .note.stapsdt in @elf and
2276 * if its an SDT note, it appends to @sdt_notes list.
2278 static int populate_sdt_note(Elf **elf, const char *data, size_t len,
2279 struct list_head *sdt_notes)
2281 const char *provider, *name, *args;
2282 struct sdt_note *tmp = NULL;
2288 Elf64_Addr a64[NR_ADDR];
2289 Elf32_Addr a32[NR_ADDR];
2293 .d_buf = &buf, .d_type = ELF_T_ADDR, .d_version = EV_CURRENT,
2294 .d_size = gelf_fsize((*elf), ELF_T_ADDR, NR_ADDR, EV_CURRENT),
2295 .d_off = 0, .d_align = 0
2298 .d_buf = (void *) data, .d_type = ELF_T_ADDR,
2299 .d_version = EV_CURRENT, .d_size = dst.d_size, .d_off = 0,
2303 tmp = (struct sdt_note *)calloc(1, sizeof(struct sdt_note));
2309 INIT_LIST_HEAD(&tmp->note_list);
2311 if (len < dst.d_size + 3)
2314 /* Translation from file representation to memory representation */
2315 if (gelf_xlatetom(*elf, &dst, &src,
2316 elf_getident(*elf, NULL)[EI_DATA]) == NULL) {
2317 pr_err("gelf_xlatetom : %s\n", elf_errmsg(-1));
2321 /* Populate the fields of sdt_note */
2322 provider = data + dst.d_size;
2324 name = (const char *)memchr(provider, '\0', data + len - provider);
2328 tmp->provider = strdup(provider);
2329 if (!tmp->provider) {
2333 tmp->name = strdup(name);
2339 args = memchr(name, '\0', data + len - name);
2342 * There is no argument if:
2343 * - We reached the end of the note;
2344 * - There is not enough room to hold a potential string;
2345 * - The argument string is empty or just contains ':'.
2347 if (args == NULL || data + len - args < 2 ||
2348 args[1] == ':' || args[1] == '\0')
2351 tmp->args = strdup(++args);
2358 if (gelf_getclass(*elf) == ELFCLASS32) {
2359 memcpy(&tmp->addr, &buf, 3 * sizeof(Elf32_Addr));
2362 memcpy(&tmp->addr, &buf, 3 * sizeof(Elf64_Addr));
2366 if (!gelf_getehdr(*elf, &ehdr)) {
2367 pr_debug("%s : cannot get elf header.\n", __func__);
2372 /* Adjust the prelink effect :
2373 * Find out the .stapsdt.base section.
2374 * This scn will help us to handle prelinking (if present).
2375 * Compare the retrieved file offset of the base section with the
2376 * base address in the description of the SDT note. If its different,
2377 * then accordingly, adjust the note location.
2379 if (elf_section_by_name(*elf, &ehdr, &shdr, SDT_BASE_SCN, NULL))
2380 sdt_adjust_loc(tmp, shdr.sh_offset);
2382 /* Adjust reference counter offset */
2383 if (elf_section_by_name(*elf, &ehdr, &shdr, SDT_PROBES_SCN, NULL))
2384 sdt_adjust_refctr(tmp, shdr.sh_addr, shdr.sh_offset);
2386 list_add_tail(&tmp->note_list, sdt_notes);
2394 zfree(&tmp->provider);
2402 * construct_sdt_notes_list : constructs a list of SDT notes
2403 * @elf : elf to look into
2404 * @sdt_notes : empty list_head
2406 * Scans the sections in 'elf' for the section
2407 * .note.stapsdt. It, then calls populate_sdt_note to find
2408 * out the SDT events and populates the 'sdt_notes'.
2410 static int construct_sdt_notes_list(Elf *elf, struct list_head *sdt_notes)
2413 Elf_Scn *scn = NULL;
2416 size_t shstrndx, next;
2418 size_t name_off, desc_off, offset;
2421 if (gelf_getehdr(elf, &ehdr) == NULL) {
2425 if (elf_getshdrstrndx(elf, &shstrndx) != 0) {
2430 /* Look for the required section */
2431 scn = elf_section_by_name(elf, &ehdr, &shdr, SDT_NOTE_SCN, NULL);
2437 if ((shdr.sh_type != SHT_NOTE) || (shdr.sh_flags & SHF_ALLOC)) {
2442 data = elf_getdata(scn, NULL);
2444 /* Get the SDT notes */
2445 for (offset = 0; (next = gelf_getnote(data, offset, &nhdr, &name_off,
2446 &desc_off)) > 0; offset = next) {
2447 if (nhdr.n_namesz == sizeof(SDT_NOTE_NAME) &&
2448 !memcmp(data->d_buf + name_off, SDT_NOTE_NAME,
2449 sizeof(SDT_NOTE_NAME))) {
2450 /* Check the type of the note */
2451 if (nhdr.n_type != SDT_NOTE_TYPE)
2454 ret = populate_sdt_note(&elf, ((data->d_buf) + desc_off),
2455 nhdr.n_descsz, sdt_notes);
2460 if (list_empty(sdt_notes))
2468 * get_sdt_note_list : Wrapper to construct a list of sdt notes
2469 * @head : empty list_head
2470 * @target : file to find SDT notes from
2472 * This opens the file, initializes
2473 * the ELF and then calls construct_sdt_notes_list.
2475 int get_sdt_note_list(struct list_head *head, const char *target)
2480 fd = open(target, O_RDONLY);
2484 elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
2489 ret = construct_sdt_notes_list(elf, head);
2497 * cleanup_sdt_note_list : free the sdt notes' list
2498 * @sdt_notes: sdt notes' list
2500 * Free up the SDT notes in @sdt_notes.
2501 * Returns the number of SDT notes free'd.
2503 int cleanup_sdt_note_list(struct list_head *sdt_notes)
2505 struct sdt_note *tmp, *pos;
2508 list_for_each_entry_safe(pos, tmp, sdt_notes, note_list) {
2509 list_del_init(&pos->note_list);
2512 zfree(&pos->provider);
2520 * sdt_notes__get_count: Counts the number of sdt events
2521 * @start: list_head to sdt_notes list
2523 * Returns the number of SDT notes in a list
2525 int sdt_notes__get_count(struct list_head *start)
2527 struct sdt_note *sdt_ptr;
2530 list_for_each_entry(sdt_ptr, start, note_list)
2536 void symbol__elf_init(void)
2538 elf_version(EV_CURRENT);