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2481 lines
56 KiB
2481 lines
56 KiB
// SPDX-License-Identifier: GPL-2.0 |
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#include <fcntl.h> |
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#include <stdio.h> |
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#include <errno.h> |
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#include <stdlib.h> |
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#include <string.h> |
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#include <unistd.h> |
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#include <inttypes.h> |
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|
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#include "dso.h" |
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#include "map.h" |
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#include "maps.h" |
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#include "symbol.h" |
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#include "symsrc.h" |
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#include "demangle-ocaml.h" |
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#include "demangle-java.h" |
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#include "demangle-rust.h" |
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#include "machine.h" |
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#include "vdso.h" |
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#include "debug.h" |
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#include "util/copyfile.h" |
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#include <linux/ctype.h> |
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#include <linux/kernel.h> |
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#include <linux/zalloc.h> |
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#include <symbol/kallsyms.h> |
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#include <internal/lib.h> |
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|
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#ifndef EM_AARCH64 |
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#define EM_AARCH64 183 /* ARM 64 bit */ |
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#endif |
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|
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#ifndef ELF32_ST_VISIBILITY |
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#define ELF32_ST_VISIBILITY(o) ((o) & 0x03) |
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#endif |
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|
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/* For ELF64 the definitions are the same. */ |
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#ifndef ELF64_ST_VISIBILITY |
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#define ELF64_ST_VISIBILITY(o) ELF32_ST_VISIBILITY (o) |
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#endif |
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|
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/* How to extract information held in the st_other field. */ |
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#ifndef GELF_ST_VISIBILITY |
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#define GELF_ST_VISIBILITY(val) ELF64_ST_VISIBILITY (val) |
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#endif |
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|
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typedef Elf64_Nhdr GElf_Nhdr; |
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|
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#ifndef DMGL_PARAMS |
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#define DMGL_NO_OPTS 0 /* For readability... */ |
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#define DMGL_PARAMS (1 << 0) /* Include function args */ |
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#define DMGL_ANSI (1 << 1) /* Include const, volatile, etc */ |
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#endif |
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|
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#ifdef HAVE_LIBBFD_SUPPORT |
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#define PACKAGE 'perf' |
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#include <bfd.h> |
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#else |
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#ifdef HAVE_CPLUS_DEMANGLE_SUPPORT |
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extern char *cplus_demangle(const char *, int); |
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|
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static inline char *bfd_demangle(void __maybe_unused *v, const char *c, int i) |
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{ |
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return cplus_demangle(c, i); |
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} |
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#else |
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#ifdef NO_DEMANGLE |
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static inline char *bfd_demangle(void __maybe_unused *v, |
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const char __maybe_unused *c, |
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int __maybe_unused i) |
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{ |
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return NULL; |
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} |
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#endif |
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#endif |
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#endif |
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|
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#ifndef HAVE_ELF_GETPHDRNUM_SUPPORT |
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static int elf_getphdrnum(Elf *elf, size_t *dst) |
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{ |
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GElf_Ehdr gehdr; |
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GElf_Ehdr *ehdr; |
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|
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ehdr = gelf_getehdr(elf, &gehdr); |
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if (!ehdr) |
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return -1; |
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|
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*dst = ehdr->e_phnum; |
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|
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return 0; |
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} |
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#endif |
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|
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#ifndef HAVE_ELF_GETSHDRSTRNDX_SUPPORT |
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static int elf_getshdrstrndx(Elf *elf __maybe_unused, size_t *dst __maybe_unused) |
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{ |
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pr_err("%s: update your libelf to > 0.140, this one lacks elf_getshdrstrndx().\n", __func__); |
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return -1; |
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} |
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#endif |
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|
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#ifndef NT_GNU_BUILD_ID |
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#define NT_GNU_BUILD_ID 3 |
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#endif |
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|
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/** |
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* elf_symtab__for_each_symbol - iterate thru all the symbols |
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* |
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* @syms: struct elf_symtab instance to iterate |
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* @idx: uint32_t idx |
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* @sym: GElf_Sym iterator |
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*/ |
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#define elf_symtab__for_each_symbol(syms, nr_syms, idx, sym) \ |
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for (idx = 0, gelf_getsym(syms, idx, &sym);\ |
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idx < nr_syms; \ |
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idx++, gelf_getsym(syms, idx, &sym)) |
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|
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static inline uint8_t elf_sym__type(const GElf_Sym *sym) |
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{ |
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return GELF_ST_TYPE(sym->st_info); |
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} |
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|
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static inline uint8_t elf_sym__visibility(const GElf_Sym *sym) |
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{ |
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return GELF_ST_VISIBILITY(sym->st_other); |
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} |
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|
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#ifndef STT_GNU_IFUNC |
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#define STT_GNU_IFUNC 10 |
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#endif |
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|
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static inline int elf_sym__is_function(const GElf_Sym *sym) |
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{ |
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return (elf_sym__type(sym) == STT_FUNC || |
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elf_sym__type(sym) == STT_GNU_IFUNC) && |
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sym->st_name != 0 && |
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sym->st_shndx != SHN_UNDEF; |
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} |
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|
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static inline bool elf_sym__is_object(const GElf_Sym *sym) |
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{ |
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return elf_sym__type(sym) == STT_OBJECT && |
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sym->st_name != 0 && |
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sym->st_shndx != SHN_UNDEF; |
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} |
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|
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static inline int elf_sym__is_label(const GElf_Sym *sym) |
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{ |
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return elf_sym__type(sym) == STT_NOTYPE && |
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sym->st_name != 0 && |
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sym->st_shndx != SHN_UNDEF && |
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sym->st_shndx != SHN_ABS && |
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elf_sym__visibility(sym) != STV_HIDDEN && |
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elf_sym__visibility(sym) != STV_INTERNAL; |
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} |
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|
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static bool elf_sym__filter(GElf_Sym *sym) |
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{ |
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return elf_sym__is_function(sym) || elf_sym__is_object(sym); |
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} |
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|
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static inline const char *elf_sym__name(const GElf_Sym *sym, |
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const Elf_Data *symstrs) |
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{ |
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return symstrs->d_buf + sym->st_name; |
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} |
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|
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static inline const char *elf_sec__name(const GElf_Shdr *shdr, |
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const Elf_Data *secstrs) |
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{ |
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return secstrs->d_buf + shdr->sh_name; |
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} |
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|
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static inline int elf_sec__is_text(const GElf_Shdr *shdr, |
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const Elf_Data *secstrs) |
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{ |
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return strstr(elf_sec__name(shdr, secstrs), "text") != NULL; |
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} |
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|
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static inline bool elf_sec__is_data(const GElf_Shdr *shdr, |
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const Elf_Data *secstrs) |
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{ |
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return strstr(elf_sec__name(shdr, secstrs), "data") != NULL; |
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} |
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|
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static bool elf_sec__filter(GElf_Shdr *shdr, Elf_Data *secstrs) |
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{ |
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return elf_sec__is_text(shdr, secstrs) || |
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elf_sec__is_data(shdr, secstrs); |
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} |
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static size_t elf_addr_to_index(Elf *elf, GElf_Addr addr) |
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{ |
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Elf_Scn *sec = NULL; |
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GElf_Shdr shdr; |
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size_t cnt = 1; |
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|
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while ((sec = elf_nextscn(elf, sec)) != NULL) { |
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gelf_getshdr(sec, &shdr); |
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|
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if ((addr >= shdr.sh_addr) && |
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(addr < (shdr.sh_addr + shdr.sh_size))) |
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return cnt; |
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|
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++cnt; |
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} |
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|
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return -1; |
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} |
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Elf_Scn *elf_section_by_name(Elf *elf, GElf_Ehdr *ep, |
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GElf_Shdr *shp, const char *name, size_t *idx) |
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{ |
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Elf_Scn *sec = NULL; |
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size_t cnt = 1; |
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|
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/* Elf is corrupted/truncated, avoid calling elf_strptr. */ |
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if (!elf_rawdata(elf_getscn(elf, ep->e_shstrndx), NULL)) |
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return NULL; |
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|
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while ((sec = elf_nextscn(elf, sec)) != NULL) { |
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char *str; |
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|
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gelf_getshdr(sec, shp); |
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str = elf_strptr(elf, ep->e_shstrndx, shp->sh_name); |
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if (str && !strcmp(name, str)) { |
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if (idx) |
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*idx = cnt; |
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return sec; |
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} |
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++cnt; |
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} |
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|
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return NULL; |
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} |
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|
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static bool want_demangle(bool is_kernel_sym) |
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{ |
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return is_kernel_sym ? symbol_conf.demangle_kernel : symbol_conf.demangle; |
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} |
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|
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static char *demangle_sym(struct dso *dso, int kmodule, const char *elf_name) |
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{ |
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int demangle_flags = verbose > 0 ? (DMGL_PARAMS | DMGL_ANSI) : DMGL_NO_OPTS; |
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char *demangled = NULL; |
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|
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/* |
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* We need to figure out if the object was created from C++ sources |
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* DWARF DW_compile_unit has this, but we don't always have access |
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* to it... |
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*/ |
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if (!want_demangle(dso->kernel || kmodule)) |
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return demangled; |
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|
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demangled = bfd_demangle(NULL, elf_name, demangle_flags); |
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if (demangled == NULL) { |
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demangled = ocaml_demangle_sym(elf_name); |
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if (demangled == NULL) { |
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demangled = java_demangle_sym(elf_name, JAVA_DEMANGLE_NORET); |
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} |
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} |
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else if (rust_is_mangled(demangled)) |
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/* |
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* Input to Rust demangling is the BFD-demangled |
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* name which it Rust-demangles in place. |
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*/ |
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rust_demangle_sym(demangled); |
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return demangled; |
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} |
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#define elf_section__for_each_rel(reldata, pos, pos_mem, idx, nr_entries) \ |
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for (idx = 0, pos = gelf_getrel(reldata, 0, &pos_mem); \ |
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idx < nr_entries; \ |
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++idx, pos = gelf_getrel(reldata, idx, &pos_mem)) |
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|
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#define elf_section__for_each_rela(reldata, pos, pos_mem, idx, nr_entries) \ |
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for (idx = 0, pos = gelf_getrela(reldata, 0, &pos_mem); \ |
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idx < nr_entries; \ |
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++idx, pos = gelf_getrela(reldata, idx, &pos_mem)) |
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|
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/* |
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* We need to check if we have a .dynsym, so that we can handle the |
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* .plt, synthesizing its symbols, that aren't on the symtabs (be it |
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* .dynsym or .symtab). |
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* And always look at the original dso, not at debuginfo packages, that |
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* have the PLT data stripped out (shdr_rel_plt.sh_type == SHT_NOBITS). |
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*/ |
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int dso__synthesize_plt_symbols(struct dso *dso, struct symsrc *ss) |
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{ |
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uint32_t nr_rel_entries, idx; |
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GElf_Sym sym; |
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u64 plt_offset, plt_header_size, plt_entry_size; |
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GElf_Shdr shdr_plt; |
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struct symbol *f; |
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GElf_Shdr shdr_rel_plt, shdr_dynsym; |
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Elf_Data *reldata, *syms, *symstrs; |
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Elf_Scn *scn_plt_rel, *scn_symstrs, *scn_dynsym; |
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size_t dynsym_idx; |
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GElf_Ehdr ehdr; |
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char sympltname[1024]; |
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Elf *elf; |
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int nr = 0, symidx, err = 0; |
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|
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if (!ss->dynsym) |
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return 0; |
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|
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elf = ss->elf; |
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ehdr = ss->ehdr; |
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scn_dynsym = ss->dynsym; |
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shdr_dynsym = ss->dynshdr; |
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dynsym_idx = ss->dynsym_idx; |
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|
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if (scn_dynsym == NULL) |
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goto out_elf_end; |
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|
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scn_plt_rel = elf_section_by_name(elf, &ehdr, &shdr_rel_plt, |
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".rela.plt", NULL); |
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if (scn_plt_rel == NULL) { |
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scn_plt_rel = elf_section_by_name(elf, &ehdr, &shdr_rel_plt, |
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".rel.plt", NULL); |
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if (scn_plt_rel == NULL) |
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goto out_elf_end; |
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} |
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|
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err = -1; |
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|
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if (shdr_rel_plt.sh_link != dynsym_idx) |
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goto out_elf_end; |
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|
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if (elf_section_by_name(elf, &ehdr, &shdr_plt, ".plt", NULL) == NULL) |
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goto out_elf_end; |
|
|
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/* |
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* Fetch the relocation section to find the idxes to the GOT |
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* and the symbols in the .dynsym they refer to. |
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*/ |
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reldata = elf_getdata(scn_plt_rel, NULL); |
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if (reldata == NULL) |
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goto out_elf_end; |
|
|
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syms = elf_getdata(scn_dynsym, NULL); |
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if (syms == NULL) |
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goto out_elf_end; |
|
|
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scn_symstrs = elf_getscn(elf, shdr_dynsym.sh_link); |
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if (scn_symstrs == NULL) |
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goto out_elf_end; |
|
|
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symstrs = elf_getdata(scn_symstrs, NULL); |
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if (symstrs == NULL) |
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goto out_elf_end; |
|
|
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if (symstrs->d_size == 0) |
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goto out_elf_end; |
|
|
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nr_rel_entries = shdr_rel_plt.sh_size / shdr_rel_plt.sh_entsize; |
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plt_offset = shdr_plt.sh_offset; |
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switch (ehdr.e_machine) { |
|
case EM_ARM: |
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plt_header_size = 20; |
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plt_entry_size = 12; |
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break; |
|
|
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case EM_AARCH64: |
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plt_header_size = 32; |
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plt_entry_size = 16; |
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break; |
|
|
|
case EM_SPARC: |
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plt_header_size = 48; |
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plt_entry_size = 12; |
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break; |
|
|
|
case EM_SPARCV9: |
|
plt_header_size = 128; |
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plt_entry_size = 32; |
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break; |
|
|
|
default: /* FIXME: s390/alpha/mips/parisc/poperpc/sh/xtensa need to be checked */ |
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plt_header_size = shdr_plt.sh_entsize; |
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plt_entry_size = shdr_plt.sh_entsize; |
|
break; |
|
} |
|
plt_offset += plt_header_size; |
|
|
|
if (shdr_rel_plt.sh_type == SHT_RELA) { |
|
GElf_Rela pos_mem, *pos; |
|
|
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elf_section__for_each_rela(reldata, pos, pos_mem, idx, |
|
nr_rel_entries) { |
|
const char *elf_name = NULL; |
|
char *demangled = NULL; |
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symidx = GELF_R_SYM(pos->r_info); |
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gelf_getsym(syms, symidx, &sym); |
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|
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elf_name = elf_sym__name(&sym, symstrs); |
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demangled = demangle_sym(dso, 0, elf_name); |
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if (demangled != NULL) |
|
elf_name = demangled; |
|
snprintf(sympltname, sizeof(sympltname), |
|
"%s@plt", elf_name); |
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free(demangled); |
|
|
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f = symbol__new(plt_offset, plt_entry_size, |
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STB_GLOBAL, STT_FUNC, sympltname); |
|
if (!f) |
|
goto out_elf_end; |
|
|
|
plt_offset += plt_entry_size; |
|
symbols__insert(&dso->symbols, f); |
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++nr; |
|
} |
|
} else if (shdr_rel_plt.sh_type == SHT_REL) { |
|
GElf_Rel pos_mem, *pos; |
|
elf_section__for_each_rel(reldata, pos, pos_mem, idx, |
|
nr_rel_entries) { |
|
const char *elf_name = NULL; |
|
char *demangled = NULL; |
|
symidx = GELF_R_SYM(pos->r_info); |
|
gelf_getsym(syms, symidx, &sym); |
|
|
|
elf_name = elf_sym__name(&sym, symstrs); |
|
demangled = demangle_sym(dso, 0, elf_name); |
|
if (demangled != NULL) |
|
elf_name = demangled; |
|
snprintf(sympltname, sizeof(sympltname), |
|
"%s@plt", elf_name); |
|
free(demangled); |
|
|
|
f = symbol__new(plt_offset, plt_entry_size, |
|
STB_GLOBAL, STT_FUNC, sympltname); |
|
if (!f) |
|
goto out_elf_end; |
|
|
|
plt_offset += plt_entry_size; |
|
symbols__insert(&dso->symbols, f); |
|
++nr; |
|
} |
|
} |
|
|
|
err = 0; |
|
out_elf_end: |
|
if (err == 0) |
|
return nr; |
|
pr_debug("%s: problems reading %s PLT info.\n", |
|
__func__, dso->long_name); |
|
return 0; |
|
} |
|
|
|
char *dso__demangle_sym(struct dso *dso, int kmodule, const char *elf_name) |
|
{ |
|
return demangle_sym(dso, kmodule, elf_name); |
|
} |
|
|
|
/* |
|
* Align offset to 4 bytes as needed for note name and descriptor data. |
|
*/ |
|
#define NOTE_ALIGN(n) (((n) + 3) & -4U) |
|
|
|
static int elf_read_build_id(Elf *elf, void *bf, size_t size) |
|
{ |
|
int err = -1; |
|
GElf_Ehdr ehdr; |
|
GElf_Shdr shdr; |
|
Elf_Data *data; |
|
Elf_Scn *sec; |
|
Elf_Kind ek; |
|
void *ptr; |
|
|
|
if (size < BUILD_ID_SIZE) |
|
goto out; |
|
|
|
ek = elf_kind(elf); |
|
if (ek != ELF_K_ELF) |
|
goto out; |
|
|
|
if (gelf_getehdr(elf, &ehdr) == NULL) { |
|
pr_err("%s: cannot get elf header.\n", __func__); |
|
goto out; |
|
} |
|
|
|
/* |
|
* Check following sections for notes: |
|
* '.note.gnu.build-id' |
|
* '.notes' |
|
* '.note' (VDSO specific) |
|
*/ |
|
do { |
|
sec = elf_section_by_name(elf, &ehdr, &shdr, |
|
".note.gnu.build-id", NULL); |
|
if (sec) |
|
break; |
|
|
|
sec = elf_section_by_name(elf, &ehdr, &shdr, |
|
".notes", NULL); |
|
if (sec) |
|
break; |
|
|
|
sec = elf_section_by_name(elf, &ehdr, &shdr, |
|
".note", NULL); |
|
if (sec) |
|
break; |
|
|
|
return err; |
|
|
|
} while (0); |
|
|
|
data = elf_getdata(sec, NULL); |
|
if (data == NULL) |
|
goto out; |
|
|
|
ptr = data->d_buf; |
|
while (ptr < (data->d_buf + data->d_size)) { |
|
GElf_Nhdr *nhdr = ptr; |
|
size_t namesz = NOTE_ALIGN(nhdr->n_namesz), |
|
descsz = NOTE_ALIGN(nhdr->n_descsz); |
|
const char *name; |
|
|
|
ptr += sizeof(*nhdr); |
|
name = ptr; |
|
ptr += namesz; |
|
if (nhdr->n_type == NT_GNU_BUILD_ID && |
|
nhdr->n_namesz == sizeof("GNU")) { |
|
if (memcmp(name, "GNU", sizeof("GNU")) == 0) { |
|
size_t sz = min(size, descsz); |
|
memcpy(bf, ptr, sz); |
|
memset(bf + sz, 0, size - sz); |
|
err = descsz; |
|
break; |
|
} |
|
} |
|
ptr += descsz; |
|
} |
|
|
|
out: |
|
return err; |
|
} |
|
|
|
#ifdef HAVE_LIBBFD_BUILDID_SUPPORT |
|
|
|
static int read_build_id(const char *filename, struct build_id *bid) |
|
{ |
|
size_t size = sizeof(bid->data); |
|
int err = -1; |
|
bfd *abfd; |
|
|
|
abfd = bfd_openr(filename, NULL); |
|
if (!abfd) |
|
return -1; |
|
|
|
if (!bfd_check_format(abfd, bfd_object)) { |
|
pr_debug2("%s: cannot read %s bfd file.\n", __func__, filename); |
|
goto out_close; |
|
} |
|
|
|
if (!abfd->build_id || abfd->build_id->size > size) |
|
goto out_close; |
|
|
|
memcpy(bid->data, abfd->build_id->data, abfd->build_id->size); |
|
memset(bid->data + abfd->build_id->size, 0, size - abfd->build_id->size); |
|
err = bid->size = abfd->build_id->size; |
|
|
|
out_close: |
|
bfd_close(abfd); |
|
return err; |
|
} |
|
|
|
#else // HAVE_LIBBFD_BUILDID_SUPPORT |
|
|
|
static int read_build_id(const char *filename, struct build_id *bid) |
|
{ |
|
size_t size = sizeof(bid->data); |
|
int fd, err = -1; |
|
Elf *elf; |
|
|
|
if (size < BUILD_ID_SIZE) |
|
goto out; |
|
|
|
fd = open(filename, O_RDONLY); |
|
if (fd < 0) |
|
goto out; |
|
|
|
elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL); |
|
if (elf == NULL) { |
|
pr_debug2("%s: cannot read %s ELF file.\n", __func__, filename); |
|
goto out_close; |
|
} |
|
|
|
err = elf_read_build_id(elf, bid->data, size); |
|
if (err > 0) |
|
bid->size = err; |
|
|
|
elf_end(elf); |
|
out_close: |
|
close(fd); |
|
out: |
|
return err; |
|
} |
|
|
|
#endif // HAVE_LIBBFD_BUILDID_SUPPORT |
|
|
|
int filename__read_build_id(const char *filename, struct build_id *bid) |
|
{ |
|
struct kmod_path m = { .name = NULL, }; |
|
char path[PATH_MAX]; |
|
int err; |
|
|
|
if (!filename) |
|
return -EFAULT; |
|
|
|
err = kmod_path__parse(&m, filename); |
|
if (err) |
|
return -1; |
|
|
|
if (m.comp) { |
|
int error = 0, fd; |
|
|
|
fd = filename__decompress(filename, path, sizeof(path), m.comp, &error); |
|
if (fd < 0) { |
|
pr_debug("Failed to decompress (error %d) %s\n", |
|
error, filename); |
|
return -1; |
|
} |
|
close(fd); |
|
filename = path; |
|
} |
|
|
|
err = read_build_id(filename, bid); |
|
|
|
if (m.comp) |
|
unlink(filename); |
|
return err; |
|
} |
|
|
|
int sysfs__read_build_id(const char *filename, struct build_id *bid) |
|
{ |
|
size_t size = sizeof(bid->data); |
|
int fd, err = -1; |
|
|
|
fd = open(filename, O_RDONLY); |
|
if (fd < 0) |
|
goto out; |
|
|
|
while (1) { |
|
char bf[BUFSIZ]; |
|
GElf_Nhdr nhdr; |
|
size_t namesz, descsz; |
|
|
|
if (read(fd, &nhdr, sizeof(nhdr)) != sizeof(nhdr)) |
|
break; |
|
|
|
namesz = NOTE_ALIGN(nhdr.n_namesz); |
|
descsz = NOTE_ALIGN(nhdr.n_descsz); |
|
if (nhdr.n_type == NT_GNU_BUILD_ID && |
|
nhdr.n_namesz == sizeof("GNU")) { |
|
if (read(fd, bf, namesz) != (ssize_t)namesz) |
|
break; |
|
if (memcmp(bf, "GNU", sizeof("GNU")) == 0) { |
|
size_t sz = min(descsz, size); |
|
if (read(fd, bid->data, sz) == (ssize_t)sz) { |
|
memset(bid->data + sz, 0, size - sz); |
|
bid->size = sz; |
|
err = 0; |
|
break; |
|
} |
|
} else if (read(fd, bf, descsz) != (ssize_t)descsz) |
|
break; |
|
} else { |
|
int n = namesz + descsz; |
|
|
|
if (n > (int)sizeof(bf)) { |
|
n = sizeof(bf); |
|
pr_debug("%s: truncating reading of build id in sysfs file %s: n_namesz=%u, n_descsz=%u.\n", |
|
__func__, filename, nhdr.n_namesz, nhdr.n_descsz); |
|
} |
|
if (read(fd, bf, n) != n) |
|
break; |
|
} |
|
} |
|
close(fd); |
|
out: |
|
return err; |
|
} |
|
|
|
#ifdef HAVE_LIBBFD_SUPPORT |
|
|
|
int filename__read_debuglink(const char *filename, char *debuglink, |
|
size_t size) |
|
{ |
|
int err = -1; |
|
asection *section; |
|
bfd *abfd; |
|
|
|
abfd = bfd_openr(filename, NULL); |
|
if (!abfd) |
|
return -1; |
|
|
|
if (!bfd_check_format(abfd, bfd_object)) { |
|
pr_debug2("%s: cannot read %s bfd file.\n", __func__, filename); |
|
goto out_close; |
|
} |
|
|
|
section = bfd_get_section_by_name(abfd, ".gnu_debuglink"); |
|
if (!section) |
|
goto out_close; |
|
|
|
if (section->size > size) |
|
goto out_close; |
|
|
|
if (!bfd_get_section_contents(abfd, section, debuglink, 0, |
|
section->size)) |
|
goto out_close; |
|
|
|
err = 0; |
|
|
|
out_close: |
|
bfd_close(abfd); |
|
return err; |
|
} |
|
|
|
#else |
|
|
|
int filename__read_debuglink(const char *filename, char *debuglink, |
|
size_t size) |
|
{ |
|
int fd, err = -1; |
|
Elf *elf; |
|
GElf_Ehdr ehdr; |
|
GElf_Shdr shdr; |
|
Elf_Data *data; |
|
Elf_Scn *sec; |
|
Elf_Kind ek; |
|
|
|
fd = open(filename, O_RDONLY); |
|
if (fd < 0) |
|
goto out; |
|
|
|
elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL); |
|
if (elf == NULL) { |
|
pr_debug2("%s: cannot read %s ELF file.\n", __func__, filename); |
|
goto out_close; |
|
} |
|
|
|
ek = elf_kind(elf); |
|
if (ek != ELF_K_ELF) |
|
goto out_elf_end; |
|
|
|
if (gelf_getehdr(elf, &ehdr) == NULL) { |
|
pr_err("%s: cannot get elf header.\n", __func__); |
|
goto out_elf_end; |
|
} |
|
|
|
sec = elf_section_by_name(elf, &ehdr, &shdr, |
|
".gnu_debuglink", NULL); |
|
if (sec == NULL) |
|
goto out_elf_end; |
|
|
|
data = elf_getdata(sec, NULL); |
|
if (data == NULL) |
|
goto out_elf_end; |
|
|
|
/* the start of this section is a zero-terminated string */ |
|
strncpy(debuglink, data->d_buf, size); |
|
|
|
err = 0; |
|
|
|
out_elf_end: |
|
elf_end(elf); |
|
out_close: |
|
close(fd); |
|
out: |
|
return err; |
|
} |
|
|
|
#endif |
|
|
|
static int dso__swap_init(struct dso *dso, unsigned char eidata) |
|
{ |
|
static unsigned int const endian = 1; |
|
|
|
dso->needs_swap = DSO_SWAP__NO; |
|
|
|
switch (eidata) { |
|
case ELFDATA2LSB: |
|
/* We are big endian, DSO is little endian. */ |
|
if (*(unsigned char const *)&endian != 1) |
|
dso->needs_swap = DSO_SWAP__YES; |
|
break; |
|
|
|
case ELFDATA2MSB: |
|
/* We are little endian, DSO is big endian. */ |
|
if (*(unsigned char const *)&endian != 0) |
|
dso->needs_swap = DSO_SWAP__YES; |
|
break; |
|
|
|
default: |
|
pr_err("unrecognized DSO data encoding %d\n", eidata); |
|
return -EINVAL; |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
bool symsrc__possibly_runtime(struct symsrc *ss) |
|
{ |
|
return ss->dynsym || ss->opdsec; |
|
} |
|
|
|
bool symsrc__has_symtab(struct symsrc *ss) |
|
{ |
|
return ss->symtab != NULL; |
|
} |
|
|
|
void symsrc__destroy(struct symsrc *ss) |
|
{ |
|
zfree(&ss->name); |
|
elf_end(ss->elf); |
|
close(ss->fd); |
|
} |
|
|
|
bool elf__needs_adjust_symbols(GElf_Ehdr ehdr) |
|
{ |
|
/* |
|
* Usually vmlinux is an ELF file with type ET_EXEC for most |
|
* architectures; except Arm64 kernel is linked with option |
|
* '-share', so need to check type ET_DYN. |
|
*/ |
|
return ehdr.e_type == ET_EXEC || ehdr.e_type == ET_REL || |
|
ehdr.e_type == ET_DYN; |
|
} |
|
|
|
int symsrc__init(struct symsrc *ss, struct dso *dso, const char *name, |
|
enum dso_binary_type type) |
|
{ |
|
GElf_Ehdr ehdr; |
|
Elf *elf; |
|
int fd; |
|
|
|
if (dso__needs_decompress(dso)) { |
|
fd = dso__decompress_kmodule_fd(dso, name); |
|
if (fd < 0) |
|
return -1; |
|
|
|
type = dso->symtab_type; |
|
} else { |
|
fd = open(name, O_RDONLY); |
|
if (fd < 0) { |
|
dso->load_errno = errno; |
|
return -1; |
|
} |
|
} |
|
|
|
elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL); |
|
if (elf == NULL) { |
|
pr_debug("%s: cannot read %s ELF file.\n", __func__, name); |
|
dso->load_errno = DSO_LOAD_ERRNO__INVALID_ELF; |
|
goto out_close; |
|
} |
|
|
|
if (gelf_getehdr(elf, &ehdr) == NULL) { |
|
dso->load_errno = DSO_LOAD_ERRNO__INVALID_ELF; |
|
pr_debug("%s: cannot get elf header.\n", __func__); |
|
goto out_elf_end; |
|
} |
|
|
|
if (dso__swap_init(dso, ehdr.e_ident[EI_DATA])) { |
|
dso->load_errno = DSO_LOAD_ERRNO__INTERNAL_ERROR; |
|
goto out_elf_end; |
|
} |
|
|
|
/* Always reject images with a mismatched build-id: */ |
|
if (dso->has_build_id && !symbol_conf.ignore_vmlinux_buildid) { |
|
u8 build_id[BUILD_ID_SIZE]; |
|
struct build_id bid; |
|
int size; |
|
|
|
size = elf_read_build_id(elf, build_id, BUILD_ID_SIZE); |
|
if (size <= 0) { |
|
dso->load_errno = DSO_LOAD_ERRNO__CANNOT_READ_BUILDID; |
|
goto out_elf_end; |
|
} |
|
|
|
build_id__init(&bid, build_id, size); |
|
if (!dso__build_id_equal(dso, &bid)) { |
|
pr_debug("%s: build id mismatch for %s.\n", __func__, name); |
|
dso->load_errno = DSO_LOAD_ERRNO__MISMATCHING_BUILDID; |
|
goto out_elf_end; |
|
} |
|
} |
|
|
|
ss->is_64_bit = (gelf_getclass(elf) == ELFCLASS64); |
|
|
|
ss->symtab = elf_section_by_name(elf, &ehdr, &ss->symshdr, ".symtab", |
|
NULL); |
|
if (ss->symshdr.sh_type != SHT_SYMTAB) |
|
ss->symtab = NULL; |
|
|
|
ss->dynsym_idx = 0; |
|
ss->dynsym = elf_section_by_name(elf, &ehdr, &ss->dynshdr, ".dynsym", |
|
&ss->dynsym_idx); |
|
if (ss->dynshdr.sh_type != SHT_DYNSYM) |
|
ss->dynsym = NULL; |
|
|
|
ss->opdidx = 0; |
|
ss->opdsec = elf_section_by_name(elf, &ehdr, &ss->opdshdr, ".opd", |
|
&ss->opdidx); |
|
if (ss->opdshdr.sh_type != SHT_PROGBITS) |
|
ss->opdsec = NULL; |
|
|
|
if (dso->kernel == DSO_SPACE__USER) |
|
ss->adjust_symbols = true; |
|
else |
|
ss->adjust_symbols = elf__needs_adjust_symbols(ehdr); |
|
|
|
ss->name = strdup(name); |
|
if (!ss->name) { |
|
dso->load_errno = errno; |
|
goto out_elf_end; |
|
} |
|
|
|
ss->elf = elf; |
|
ss->fd = fd; |
|
ss->ehdr = ehdr; |
|
ss->type = type; |
|
|
|
return 0; |
|
|
|
out_elf_end: |
|
elf_end(elf); |
|
out_close: |
|
close(fd); |
|
return -1; |
|
} |
|
|
|
/** |
|
* ref_reloc_sym_not_found - has kernel relocation symbol been found. |
|
* @kmap: kernel maps and relocation reference symbol |
|
* |
|
* This function returns %true if we are dealing with the kernel maps and the |
|
* relocation reference symbol has not yet been found. Otherwise %false is |
|
* returned. |
|
*/ |
|
static bool ref_reloc_sym_not_found(struct kmap *kmap) |
|
{ |
|
return kmap && kmap->ref_reloc_sym && kmap->ref_reloc_sym->name && |
|
!kmap->ref_reloc_sym->unrelocated_addr; |
|
} |
|
|
|
/** |
|
* ref_reloc - kernel relocation offset. |
|
* @kmap: kernel maps and relocation reference symbol |
|
* |
|
* This function returns the offset of kernel addresses as determined by using |
|
* the relocation reference symbol i.e. if the kernel has not been relocated |
|
* then the return value is zero. |
|
*/ |
|
static u64 ref_reloc(struct kmap *kmap) |
|
{ |
|
if (kmap && kmap->ref_reloc_sym && |
|
kmap->ref_reloc_sym->unrelocated_addr) |
|
return kmap->ref_reloc_sym->addr - |
|
kmap->ref_reloc_sym->unrelocated_addr; |
|
return 0; |
|
} |
|
|
|
void __weak arch__sym_update(struct symbol *s __maybe_unused, |
|
GElf_Sym *sym __maybe_unused) { } |
|
|
|
static int dso__process_kernel_symbol(struct dso *dso, struct map *map, |
|
GElf_Sym *sym, GElf_Shdr *shdr, |
|
struct maps *kmaps, struct kmap *kmap, |
|
struct dso **curr_dsop, struct map **curr_mapp, |
|
const char *section_name, |
|
bool adjust_kernel_syms, bool kmodule, bool *remap_kernel) |
|
{ |
|
struct dso *curr_dso = *curr_dsop; |
|
struct map *curr_map; |
|
char dso_name[PATH_MAX]; |
|
|
|
/* Adjust symbol to map to file offset */ |
|
if (adjust_kernel_syms) |
|
sym->st_value -= shdr->sh_addr - shdr->sh_offset; |
|
|
|
if (strcmp(section_name, (curr_dso->short_name + dso->short_name_len)) == 0) |
|
return 0; |
|
|
|
if (strcmp(section_name, ".text") == 0) { |
|
/* |
|
* The initial kernel mapping is based on |
|
* kallsyms and identity maps. Overwrite it to |
|
* map to the kernel dso. |
|
*/ |
|
if (*remap_kernel && dso->kernel && !kmodule) { |
|
*remap_kernel = false; |
|
map->start = shdr->sh_addr + ref_reloc(kmap); |
|
map->end = map->start + shdr->sh_size; |
|
map->pgoff = shdr->sh_offset; |
|
map->map_ip = map__map_ip; |
|
map->unmap_ip = map__unmap_ip; |
|
/* Ensure maps are correctly ordered */ |
|
if (kmaps) { |
|
map__get(map); |
|
maps__remove(kmaps, map); |
|
maps__insert(kmaps, map); |
|
map__put(map); |
|
} |
|
} |
|
|
|
/* |
|
* The initial module mapping is based on |
|
* /proc/modules mapped to offset zero. |
|
* Overwrite it to map to the module dso. |
|
*/ |
|
if (*remap_kernel && kmodule) { |
|
*remap_kernel = false; |
|
map->pgoff = shdr->sh_offset; |
|
} |
|
|
|
*curr_mapp = map; |
|
*curr_dsop = dso; |
|
return 0; |
|
} |
|
|
|
if (!kmap) |
|
return 0; |
|
|
|
snprintf(dso_name, sizeof(dso_name), "%s%s", dso->short_name, section_name); |
|
|
|
curr_map = maps__find_by_name(kmaps, dso_name); |
|
if (curr_map == NULL) { |
|
u64 start = sym->st_value; |
|
|
|
if (kmodule) |
|
start += map->start + shdr->sh_offset; |
|
|
|
curr_dso = dso__new(dso_name); |
|
if (curr_dso == NULL) |
|
return -1; |
|
curr_dso->kernel = dso->kernel; |
|
curr_dso->long_name = dso->long_name; |
|
curr_dso->long_name_len = dso->long_name_len; |
|
curr_map = map__new2(start, curr_dso); |
|
dso__put(curr_dso); |
|
if (curr_map == NULL) |
|
return -1; |
|
|
|
if (curr_dso->kernel) |
|
map__kmap(curr_map)->kmaps = kmaps; |
|
|
|
if (adjust_kernel_syms) { |
|
curr_map->start = shdr->sh_addr + ref_reloc(kmap); |
|
curr_map->end = curr_map->start + shdr->sh_size; |
|
curr_map->pgoff = shdr->sh_offset; |
|
} else { |
|
curr_map->map_ip = curr_map->unmap_ip = identity__map_ip; |
|
} |
|
curr_dso->symtab_type = dso->symtab_type; |
|
maps__insert(kmaps, curr_map); |
|
/* |
|
* Add it before we drop the reference to curr_map, i.e. while |
|
* we still are sure to have a reference to this DSO via |
|
* *curr_map->dso. |
|
*/ |
|
dsos__add(&kmaps->machine->dsos, curr_dso); |
|
/* kmaps already got it */ |
|
map__put(curr_map); |
|
dso__set_loaded(curr_dso); |
|
*curr_mapp = curr_map; |
|
*curr_dsop = curr_dso; |
|
} else |
|
*curr_dsop = curr_map->dso; |
|
|
|
return 0; |
|
} |
|
|
|
static int |
|
dso__load_sym_internal(struct dso *dso, struct map *map, struct symsrc *syms_ss, |
|
struct symsrc *runtime_ss, int kmodule, int dynsym) |
|
{ |
|
struct kmap *kmap = dso->kernel ? map__kmap(map) : NULL; |
|
struct maps *kmaps = kmap ? map__kmaps(map) : NULL; |
|
struct map *curr_map = map; |
|
struct dso *curr_dso = dso; |
|
Elf_Data *symstrs, *secstrs, *secstrs_run, *secstrs_sym; |
|
uint32_t nr_syms; |
|
int err = -1; |
|
uint32_t idx; |
|
GElf_Ehdr ehdr; |
|
GElf_Shdr shdr; |
|
GElf_Shdr tshdr; |
|
Elf_Data *syms, *opddata = NULL; |
|
GElf_Sym sym; |
|
Elf_Scn *sec, *sec_strndx; |
|
Elf *elf; |
|
int nr = 0; |
|
bool remap_kernel = false, adjust_kernel_syms = false; |
|
|
|
if (kmap && !kmaps) |
|
return -1; |
|
|
|
elf = syms_ss->elf; |
|
ehdr = syms_ss->ehdr; |
|
if (dynsym) { |
|
sec = syms_ss->dynsym; |
|
shdr = syms_ss->dynshdr; |
|
} else { |
|
sec = syms_ss->symtab; |
|
shdr = syms_ss->symshdr; |
|
} |
|
|
|
if (elf_section_by_name(runtime_ss->elf, &runtime_ss->ehdr, &tshdr, |
|
".text", NULL)) |
|
dso->text_offset = tshdr.sh_addr - tshdr.sh_offset; |
|
|
|
if (runtime_ss->opdsec) |
|
opddata = elf_rawdata(runtime_ss->opdsec, NULL); |
|
|
|
syms = elf_getdata(sec, NULL); |
|
if (syms == NULL) |
|
goto out_elf_end; |
|
|
|
sec = elf_getscn(elf, shdr.sh_link); |
|
if (sec == NULL) |
|
goto out_elf_end; |
|
|
|
symstrs = elf_getdata(sec, NULL); |
|
if (symstrs == NULL) |
|
goto out_elf_end; |
|
|
|
sec_strndx = elf_getscn(runtime_ss->elf, runtime_ss->ehdr.e_shstrndx); |
|
if (sec_strndx == NULL) |
|
goto out_elf_end; |
|
|
|
secstrs_run = elf_getdata(sec_strndx, NULL); |
|
if (secstrs_run == NULL) |
|
goto out_elf_end; |
|
|
|
sec_strndx = elf_getscn(elf, ehdr.e_shstrndx); |
|
if (sec_strndx == NULL) |
|
goto out_elf_end; |
|
|
|
secstrs_sym = elf_getdata(sec_strndx, NULL); |
|
if (secstrs_sym == NULL) |
|
goto out_elf_end; |
|
|
|
nr_syms = shdr.sh_size / shdr.sh_entsize; |
|
|
|
memset(&sym, 0, sizeof(sym)); |
|
|
|
/* |
|
* The kernel relocation symbol is needed in advance in order to adjust |
|
* kernel maps correctly. |
|
*/ |
|
if (ref_reloc_sym_not_found(kmap)) { |
|
elf_symtab__for_each_symbol(syms, nr_syms, idx, sym) { |
|
const char *elf_name = elf_sym__name(&sym, symstrs); |
|
|
|
if (strcmp(elf_name, kmap->ref_reloc_sym->name)) |
|
continue; |
|
kmap->ref_reloc_sym->unrelocated_addr = sym.st_value; |
|
map->reloc = kmap->ref_reloc_sym->addr - |
|
kmap->ref_reloc_sym->unrelocated_addr; |
|
break; |
|
} |
|
} |
|
|
|
/* |
|
* Handle any relocation of vdso necessary because older kernels |
|
* attempted to prelink vdso to its virtual address. |
|
*/ |
|
if (dso__is_vdso(dso)) |
|
map->reloc = map->start - dso->text_offset; |
|
|
|
dso->adjust_symbols = runtime_ss->adjust_symbols || ref_reloc(kmap); |
|
/* |
|
* Initial kernel and module mappings do not map to the dso. |
|
* Flag the fixups. |
|
*/ |
|
if (dso->kernel) { |
|
remap_kernel = true; |
|
adjust_kernel_syms = dso->adjust_symbols; |
|
} |
|
elf_symtab__for_each_symbol(syms, nr_syms, idx, sym) { |
|
struct symbol *f; |
|
const char *elf_name = elf_sym__name(&sym, symstrs); |
|
char *demangled = NULL; |
|
int is_label = elf_sym__is_label(&sym); |
|
const char *section_name; |
|
bool used_opd = false; |
|
|
|
if (!is_label && !elf_sym__filter(&sym)) |
|
continue; |
|
|
|
/* Reject ARM ELF "mapping symbols": these aren't unique and |
|
* don't identify functions, so will confuse the profile |
|
* output: */ |
|
if (ehdr.e_machine == EM_ARM || ehdr.e_machine == EM_AARCH64) { |
|
if (elf_name[0] == '$' && strchr("adtx", elf_name[1]) |
|
&& (elf_name[2] == '\0' || elf_name[2] == '.')) |
|
continue; |
|
} |
|
|
|
if (runtime_ss->opdsec && sym.st_shndx == runtime_ss->opdidx) { |
|
u32 offset = sym.st_value - syms_ss->opdshdr.sh_addr; |
|
u64 *opd = opddata->d_buf + offset; |
|
sym.st_value = DSO__SWAP(dso, u64, *opd); |
|
sym.st_shndx = elf_addr_to_index(runtime_ss->elf, |
|
sym.st_value); |
|
used_opd = true; |
|
} |
|
/* |
|
* When loading symbols in a data mapping, ABS symbols (which |
|
* has a value of SHN_ABS in its st_shndx) failed at |
|
* elf_getscn(). And it marks the loading as a failure so |
|
* already loaded symbols cannot be fixed up. |
|
* |
|
* I'm not sure what should be done. Just ignore them for now. |
|
* - Namhyung Kim |
|
*/ |
|
if (sym.st_shndx == SHN_ABS) |
|
continue; |
|
|
|
sec = elf_getscn(syms_ss->elf, sym.st_shndx); |
|
if (!sec) |
|
goto out_elf_end; |
|
|
|
gelf_getshdr(sec, &shdr); |
|
|
|
secstrs = secstrs_sym; |
|
|
|
/* |
|
* We have to fallback to runtime when syms' section header has |
|
* NOBITS set. NOBITS results in file offset (sh_offset) not |
|
* being incremented. So sh_offset used below has different |
|
* values for syms (invalid) and runtime (valid). |
|
*/ |
|
if (shdr.sh_type == SHT_NOBITS) { |
|
sec = elf_getscn(runtime_ss->elf, sym.st_shndx); |
|
if (!sec) |
|
goto out_elf_end; |
|
|
|
gelf_getshdr(sec, &shdr); |
|
secstrs = secstrs_run; |
|
} |
|
|
|
if (is_label && !elf_sec__filter(&shdr, secstrs)) |
|
continue; |
|
|
|
section_name = elf_sec__name(&shdr, secstrs); |
|
|
|
/* On ARM, symbols for thumb functions have 1 added to |
|
* the symbol address as a flag - remove it */ |
|
if ((ehdr.e_machine == EM_ARM) && |
|
(GELF_ST_TYPE(sym.st_info) == STT_FUNC) && |
|
(sym.st_value & 1)) |
|
--sym.st_value; |
|
|
|
if (dso->kernel) { |
|
if (dso__process_kernel_symbol(dso, map, &sym, &shdr, kmaps, kmap, &curr_dso, &curr_map, |
|
section_name, adjust_kernel_syms, kmodule, &remap_kernel)) |
|
goto out_elf_end; |
|
} else if ((used_opd && runtime_ss->adjust_symbols) || |
|
(!used_opd && syms_ss->adjust_symbols)) { |
|
pr_debug4("%s: adjusting symbol: st_value: %#" PRIx64 " " |
|
"sh_addr: %#" PRIx64 " sh_offset: %#" PRIx64 "\n", __func__, |
|
(u64)sym.st_value, (u64)shdr.sh_addr, |
|
(u64)shdr.sh_offset); |
|
sym.st_value -= shdr.sh_addr - shdr.sh_offset; |
|
} |
|
|
|
demangled = demangle_sym(dso, kmodule, elf_name); |
|
if (demangled != NULL) |
|
elf_name = demangled; |
|
|
|
f = symbol__new(sym.st_value, sym.st_size, |
|
GELF_ST_BIND(sym.st_info), |
|
GELF_ST_TYPE(sym.st_info), elf_name); |
|
free(demangled); |
|
if (!f) |
|
goto out_elf_end; |
|
|
|
arch__sym_update(f, &sym); |
|
|
|
__symbols__insert(&curr_dso->symbols, f, dso->kernel); |
|
nr++; |
|
} |
|
|
|
/* |
|
* For misannotated, zeroed, ASM function sizes. |
|
*/ |
|
if (nr > 0) { |
|
symbols__fixup_end(&dso->symbols); |
|
symbols__fixup_duplicate(&dso->symbols); |
|
if (kmap) { |
|
/* |
|
* We need to fixup this here too because we create new |
|
* maps here, for things like vsyscall sections. |
|
*/ |
|
maps__fixup_end(kmaps); |
|
} |
|
} |
|
err = nr; |
|
out_elf_end: |
|
return err; |
|
} |
|
|
|
int dso__load_sym(struct dso *dso, struct map *map, struct symsrc *syms_ss, |
|
struct symsrc *runtime_ss, int kmodule) |
|
{ |
|
int nr = 0; |
|
int err = -1; |
|
|
|
dso->symtab_type = syms_ss->type; |
|
dso->is_64_bit = syms_ss->is_64_bit; |
|
dso->rel = syms_ss->ehdr.e_type == ET_REL; |
|
|
|
/* |
|
* Modules may already have symbols from kallsyms, but those symbols |
|
* have the wrong values for the dso maps, so remove them. |
|
*/ |
|
if (kmodule && syms_ss->symtab) |
|
symbols__delete(&dso->symbols); |
|
|
|
if (!syms_ss->symtab) { |
|
/* |
|
* If the vmlinux is stripped, fail so we will fall back |
|
* to using kallsyms. The vmlinux runtime symbols aren't |
|
* of much use. |
|
*/ |
|
if (dso->kernel) |
|
return err; |
|
} else { |
|
err = dso__load_sym_internal(dso, map, syms_ss, runtime_ss, |
|
kmodule, 0); |
|
if (err < 0) |
|
return err; |
|
nr = err; |
|
} |
|
|
|
if (syms_ss->dynsym) { |
|
err = dso__load_sym_internal(dso, map, syms_ss, runtime_ss, |
|
kmodule, 1); |
|
if (err < 0) |
|
return err; |
|
err += nr; |
|
} |
|
|
|
return err; |
|
} |
|
|
|
static int elf_read_maps(Elf *elf, bool exe, mapfn_t mapfn, void *data) |
|
{ |
|
GElf_Phdr phdr; |
|
size_t i, phdrnum; |
|
int err; |
|
u64 sz; |
|
|
|
if (elf_getphdrnum(elf, &phdrnum)) |
|
return -1; |
|
|
|
for (i = 0; i < phdrnum; i++) { |
|
if (gelf_getphdr(elf, i, &phdr) == NULL) |
|
return -1; |
|
if (phdr.p_type != PT_LOAD) |
|
continue; |
|
if (exe) { |
|
if (!(phdr.p_flags & PF_X)) |
|
continue; |
|
} else { |
|
if (!(phdr.p_flags & PF_R)) |
|
continue; |
|
} |
|
sz = min(phdr.p_memsz, phdr.p_filesz); |
|
if (!sz) |
|
continue; |
|
err = mapfn(phdr.p_vaddr, sz, phdr.p_offset, data); |
|
if (err) |
|
return err; |
|
} |
|
return 0; |
|
} |
|
|
|
int file__read_maps(int fd, bool exe, mapfn_t mapfn, void *data, |
|
bool *is_64_bit) |
|
{ |
|
int err; |
|
Elf *elf; |
|
|
|
elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL); |
|
if (elf == NULL) |
|
return -1; |
|
|
|
if (is_64_bit) |
|
*is_64_bit = (gelf_getclass(elf) == ELFCLASS64); |
|
|
|
err = elf_read_maps(elf, exe, mapfn, data); |
|
|
|
elf_end(elf); |
|
return err; |
|
} |
|
|
|
enum dso_type dso__type_fd(int fd) |
|
{ |
|
enum dso_type dso_type = DSO__TYPE_UNKNOWN; |
|
GElf_Ehdr ehdr; |
|
Elf_Kind ek; |
|
Elf *elf; |
|
|
|
elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL); |
|
if (elf == NULL) |
|
goto out; |
|
|
|
ek = elf_kind(elf); |
|
if (ek != ELF_K_ELF) |
|
goto out_end; |
|
|
|
if (gelf_getclass(elf) == ELFCLASS64) { |
|
dso_type = DSO__TYPE_64BIT; |
|
goto out_end; |
|
} |
|
|
|
if (gelf_getehdr(elf, &ehdr) == NULL) |
|
goto out_end; |
|
|
|
if (ehdr.e_machine == EM_X86_64) |
|
dso_type = DSO__TYPE_X32BIT; |
|
else |
|
dso_type = DSO__TYPE_32BIT; |
|
out_end: |
|
elf_end(elf); |
|
out: |
|
return dso_type; |
|
} |
|
|
|
static int copy_bytes(int from, off_t from_offs, int to, off_t to_offs, u64 len) |
|
{ |
|
ssize_t r; |
|
size_t n; |
|
int err = -1; |
|
char *buf = malloc(page_size); |
|
|
|
if (buf == NULL) |
|
return -1; |
|
|
|
if (lseek(to, to_offs, SEEK_SET) != to_offs) |
|
goto out; |
|
|
|
if (lseek(from, from_offs, SEEK_SET) != from_offs) |
|
goto out; |
|
|
|
while (len) { |
|
n = page_size; |
|
if (len < n) |
|
n = len; |
|
/* Use read because mmap won't work on proc files */ |
|
r = read(from, buf, n); |
|
if (r < 0) |
|
goto out; |
|
if (!r) |
|
break; |
|
n = r; |
|
r = write(to, buf, n); |
|
if (r < 0) |
|
goto out; |
|
if ((size_t)r != n) |
|
goto out; |
|
len -= n; |
|
} |
|
|
|
err = 0; |
|
out: |
|
free(buf); |
|
return err; |
|
} |
|
|
|
struct kcore { |
|
int fd; |
|
int elfclass; |
|
Elf *elf; |
|
GElf_Ehdr ehdr; |
|
}; |
|
|
|
static int kcore__open(struct kcore *kcore, const char *filename) |
|
{ |
|
GElf_Ehdr *ehdr; |
|
|
|
kcore->fd = open(filename, O_RDONLY); |
|
if (kcore->fd == -1) |
|
return -1; |
|
|
|
kcore->elf = elf_begin(kcore->fd, ELF_C_READ, NULL); |
|
if (!kcore->elf) |
|
goto out_close; |
|
|
|
kcore->elfclass = gelf_getclass(kcore->elf); |
|
if (kcore->elfclass == ELFCLASSNONE) |
|
goto out_end; |
|
|
|
ehdr = gelf_getehdr(kcore->elf, &kcore->ehdr); |
|
if (!ehdr) |
|
goto out_end; |
|
|
|
return 0; |
|
|
|
out_end: |
|
elf_end(kcore->elf); |
|
out_close: |
|
close(kcore->fd); |
|
return -1; |
|
} |
|
|
|
static int kcore__init(struct kcore *kcore, char *filename, int elfclass, |
|
bool temp) |
|
{ |
|
kcore->elfclass = elfclass; |
|
|
|
if (temp) |
|
kcore->fd = mkstemp(filename); |
|
else |
|
kcore->fd = open(filename, O_WRONLY | O_CREAT | O_EXCL, 0400); |
|
if (kcore->fd == -1) |
|
return -1; |
|
|
|
kcore->elf = elf_begin(kcore->fd, ELF_C_WRITE, NULL); |
|
if (!kcore->elf) |
|
goto out_close; |
|
|
|
if (!gelf_newehdr(kcore->elf, elfclass)) |
|
goto out_end; |
|
|
|
memset(&kcore->ehdr, 0, sizeof(GElf_Ehdr)); |
|
|
|
return 0; |
|
|
|
out_end: |
|
elf_end(kcore->elf); |
|
out_close: |
|
close(kcore->fd); |
|
unlink(filename); |
|
return -1; |
|
} |
|
|
|
static void kcore__close(struct kcore *kcore) |
|
{ |
|
elf_end(kcore->elf); |
|
close(kcore->fd); |
|
} |
|
|
|
static int kcore__copy_hdr(struct kcore *from, struct kcore *to, size_t count) |
|
{ |
|
GElf_Ehdr *ehdr = &to->ehdr; |
|
GElf_Ehdr *kehdr = &from->ehdr; |
|
|
|
memcpy(ehdr->e_ident, kehdr->e_ident, EI_NIDENT); |
|
ehdr->e_type = kehdr->e_type; |
|
ehdr->e_machine = kehdr->e_machine; |
|
ehdr->e_version = kehdr->e_version; |
|
ehdr->e_entry = 0; |
|
ehdr->e_shoff = 0; |
|
ehdr->e_flags = kehdr->e_flags; |
|
ehdr->e_phnum = count; |
|
ehdr->e_shentsize = 0; |
|
ehdr->e_shnum = 0; |
|
ehdr->e_shstrndx = 0; |
|
|
|
if (from->elfclass == ELFCLASS32) { |
|
ehdr->e_phoff = sizeof(Elf32_Ehdr); |
|
ehdr->e_ehsize = sizeof(Elf32_Ehdr); |
|
ehdr->e_phentsize = sizeof(Elf32_Phdr); |
|
} else { |
|
ehdr->e_phoff = sizeof(Elf64_Ehdr); |
|
ehdr->e_ehsize = sizeof(Elf64_Ehdr); |
|
ehdr->e_phentsize = sizeof(Elf64_Phdr); |
|
} |
|
|
|
if (!gelf_update_ehdr(to->elf, ehdr)) |
|
return -1; |
|
|
|
if (!gelf_newphdr(to->elf, count)) |
|
return -1; |
|
|
|
return 0; |
|
} |
|
|
|
static int kcore__add_phdr(struct kcore *kcore, int idx, off_t offset, |
|
u64 addr, u64 len) |
|
{ |
|
GElf_Phdr phdr = { |
|
.p_type = PT_LOAD, |
|
.p_flags = PF_R | PF_W | PF_X, |
|
.p_offset = offset, |
|
.p_vaddr = addr, |
|
.p_paddr = 0, |
|
.p_filesz = len, |
|
.p_memsz = len, |
|
.p_align = page_size, |
|
}; |
|
|
|
if (!gelf_update_phdr(kcore->elf, idx, &phdr)) |
|
return -1; |
|
|
|
return 0; |
|
} |
|
|
|
static off_t kcore__write(struct kcore *kcore) |
|
{ |
|
return elf_update(kcore->elf, ELF_C_WRITE); |
|
} |
|
|
|
struct phdr_data { |
|
off_t offset; |
|
off_t rel; |
|
u64 addr; |
|
u64 len; |
|
struct list_head node; |
|
struct phdr_data *remaps; |
|
}; |
|
|
|
struct sym_data { |
|
u64 addr; |
|
struct list_head node; |
|
}; |
|
|
|
struct kcore_copy_info { |
|
u64 stext; |
|
u64 etext; |
|
u64 first_symbol; |
|
u64 last_symbol; |
|
u64 first_module; |
|
u64 first_module_symbol; |
|
u64 last_module_symbol; |
|
size_t phnum; |
|
struct list_head phdrs; |
|
struct list_head syms; |
|
}; |
|
|
|
#define kcore_copy__for_each_phdr(k, p) \ |
|
list_for_each_entry((p), &(k)->phdrs, node) |
|
|
|
static struct phdr_data *phdr_data__new(u64 addr, u64 len, off_t offset) |
|
{ |
|
struct phdr_data *p = zalloc(sizeof(*p)); |
|
|
|
if (p) { |
|
p->addr = addr; |
|
p->len = len; |
|
p->offset = offset; |
|
} |
|
|
|
return p; |
|
} |
|
|
|
static struct phdr_data *kcore_copy_info__addnew(struct kcore_copy_info *kci, |
|
u64 addr, u64 len, |
|
off_t offset) |
|
{ |
|
struct phdr_data *p = phdr_data__new(addr, len, offset); |
|
|
|
if (p) |
|
list_add_tail(&p->node, &kci->phdrs); |
|
|
|
return p; |
|
} |
|
|
|
static void kcore_copy__free_phdrs(struct kcore_copy_info *kci) |
|
{ |
|
struct phdr_data *p, *tmp; |
|
|
|
list_for_each_entry_safe(p, tmp, &kci->phdrs, node) { |
|
list_del_init(&p->node); |
|
free(p); |
|
} |
|
} |
|
|
|
static struct sym_data *kcore_copy__new_sym(struct kcore_copy_info *kci, |
|
u64 addr) |
|
{ |
|
struct sym_data *s = zalloc(sizeof(*s)); |
|
|
|
if (s) { |
|
s->addr = addr; |
|
list_add_tail(&s->node, &kci->syms); |
|
} |
|
|
|
return s; |
|
} |
|
|
|
static void kcore_copy__free_syms(struct kcore_copy_info *kci) |
|
{ |
|
struct sym_data *s, *tmp; |
|
|
|
list_for_each_entry_safe(s, tmp, &kci->syms, node) { |
|
list_del_init(&s->node); |
|
free(s); |
|
} |
|
} |
|
|
|
static int kcore_copy__process_kallsyms(void *arg, const char *name, char type, |
|
u64 start) |
|
{ |
|
struct kcore_copy_info *kci = arg; |
|
|
|
if (!kallsyms__is_function(type)) |
|
return 0; |
|
|
|
if (strchr(name, '[')) { |
|
if (!kci->first_module_symbol || start < kci->first_module_symbol) |
|
kci->first_module_symbol = start; |
|
if (start > kci->last_module_symbol) |
|
kci->last_module_symbol = start; |
|
return 0; |
|
} |
|
|
|
if (!kci->first_symbol || start < kci->first_symbol) |
|
kci->first_symbol = start; |
|
|
|
if (!kci->last_symbol || start > kci->last_symbol) |
|
kci->last_symbol = start; |
|
|
|
if (!strcmp(name, "_stext")) { |
|
kci->stext = start; |
|
return 0; |
|
} |
|
|
|
if (!strcmp(name, "_etext")) { |
|
kci->etext = start; |
|
return 0; |
|
} |
|
|
|
if (is_entry_trampoline(name) && !kcore_copy__new_sym(kci, start)) |
|
return -1; |
|
|
|
return 0; |
|
} |
|
|
|
static int kcore_copy__parse_kallsyms(struct kcore_copy_info *kci, |
|
const char *dir) |
|
{ |
|
char kallsyms_filename[PATH_MAX]; |
|
|
|
scnprintf(kallsyms_filename, PATH_MAX, "%s/kallsyms", dir); |
|
|
|
if (symbol__restricted_filename(kallsyms_filename, "/proc/kallsyms")) |
|
return -1; |
|
|
|
if (kallsyms__parse(kallsyms_filename, kci, |
|
kcore_copy__process_kallsyms) < 0) |
|
return -1; |
|
|
|
return 0; |
|
} |
|
|
|
static int kcore_copy__process_modules(void *arg, |
|
const char *name __maybe_unused, |
|
u64 start, u64 size __maybe_unused) |
|
{ |
|
struct kcore_copy_info *kci = arg; |
|
|
|
if (!kci->first_module || start < kci->first_module) |
|
kci->first_module = start; |
|
|
|
return 0; |
|
} |
|
|
|
static int kcore_copy__parse_modules(struct kcore_copy_info *kci, |
|
const char *dir) |
|
{ |
|
char modules_filename[PATH_MAX]; |
|
|
|
scnprintf(modules_filename, PATH_MAX, "%s/modules", dir); |
|
|
|
if (symbol__restricted_filename(modules_filename, "/proc/modules")) |
|
return -1; |
|
|
|
if (modules__parse(modules_filename, kci, |
|
kcore_copy__process_modules) < 0) |
|
return -1; |
|
|
|
return 0; |
|
} |
|
|
|
static int kcore_copy__map(struct kcore_copy_info *kci, u64 start, u64 end, |
|
u64 pgoff, u64 s, u64 e) |
|
{ |
|
u64 len, offset; |
|
|
|
if (s < start || s >= end) |
|
return 0; |
|
|
|
offset = (s - start) + pgoff; |
|
len = e < end ? e - s : end - s; |
|
|
|
return kcore_copy_info__addnew(kci, s, len, offset) ? 0 : -1; |
|
} |
|
|
|
static int kcore_copy__read_map(u64 start, u64 len, u64 pgoff, void *data) |
|
{ |
|
struct kcore_copy_info *kci = data; |
|
u64 end = start + len; |
|
struct sym_data *sdat; |
|
|
|
if (kcore_copy__map(kci, start, end, pgoff, kci->stext, kci->etext)) |
|
return -1; |
|
|
|
if (kcore_copy__map(kci, start, end, pgoff, kci->first_module, |
|
kci->last_module_symbol)) |
|
return -1; |
|
|
|
list_for_each_entry(sdat, &kci->syms, node) { |
|
u64 s = round_down(sdat->addr, page_size); |
|
|
|
if (kcore_copy__map(kci, start, end, pgoff, s, s + len)) |
|
return -1; |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
static int kcore_copy__read_maps(struct kcore_copy_info *kci, Elf *elf) |
|
{ |
|
if (elf_read_maps(elf, true, kcore_copy__read_map, kci) < 0) |
|
return -1; |
|
|
|
return 0; |
|
} |
|
|
|
static void kcore_copy__find_remaps(struct kcore_copy_info *kci) |
|
{ |
|
struct phdr_data *p, *k = NULL; |
|
u64 kend; |
|
|
|
if (!kci->stext) |
|
return; |
|
|
|
/* Find phdr that corresponds to the kernel map (contains stext) */ |
|
kcore_copy__for_each_phdr(kci, p) { |
|
u64 pend = p->addr + p->len - 1; |
|
|
|
if (p->addr <= kci->stext && pend >= kci->stext) { |
|
k = p; |
|
break; |
|
} |
|
} |
|
|
|
if (!k) |
|
return; |
|
|
|
kend = k->offset + k->len; |
|
|
|
/* Find phdrs that remap the kernel */ |
|
kcore_copy__for_each_phdr(kci, p) { |
|
u64 pend = p->offset + p->len; |
|
|
|
if (p == k) |
|
continue; |
|
|
|
if (p->offset >= k->offset && pend <= kend) |
|
p->remaps = k; |
|
} |
|
} |
|
|
|
static void kcore_copy__layout(struct kcore_copy_info *kci) |
|
{ |
|
struct phdr_data *p; |
|
off_t rel = 0; |
|
|
|
kcore_copy__find_remaps(kci); |
|
|
|
kcore_copy__for_each_phdr(kci, p) { |
|
if (!p->remaps) { |
|
p->rel = rel; |
|
rel += p->len; |
|
} |
|
kci->phnum += 1; |
|
} |
|
|
|
kcore_copy__for_each_phdr(kci, p) { |
|
struct phdr_data *k = p->remaps; |
|
|
|
if (k) |
|
p->rel = p->offset - k->offset + k->rel; |
|
} |
|
} |
|
|
|
static int kcore_copy__calc_maps(struct kcore_copy_info *kci, const char *dir, |
|
Elf *elf) |
|
{ |
|
if (kcore_copy__parse_kallsyms(kci, dir)) |
|
return -1; |
|
|
|
if (kcore_copy__parse_modules(kci, dir)) |
|
return -1; |
|
|
|
if (kci->stext) |
|
kci->stext = round_down(kci->stext, page_size); |
|
else |
|
kci->stext = round_down(kci->first_symbol, page_size); |
|
|
|
if (kci->etext) { |
|
kci->etext = round_up(kci->etext, page_size); |
|
} else if (kci->last_symbol) { |
|
kci->etext = round_up(kci->last_symbol, page_size); |
|
kci->etext += page_size; |
|
} |
|
|
|
if (kci->first_module_symbol && |
|
(!kci->first_module || kci->first_module_symbol < kci->first_module)) |
|
kci->first_module = kci->first_module_symbol; |
|
|
|
kci->first_module = round_down(kci->first_module, page_size); |
|
|
|
if (kci->last_module_symbol) { |
|
kci->last_module_symbol = round_up(kci->last_module_symbol, |
|
page_size); |
|
kci->last_module_symbol += page_size; |
|
} |
|
|
|
if (!kci->stext || !kci->etext) |
|
return -1; |
|
|
|
if (kci->first_module && !kci->last_module_symbol) |
|
return -1; |
|
|
|
if (kcore_copy__read_maps(kci, elf)) |
|
return -1; |
|
|
|
kcore_copy__layout(kci); |
|
|
|
return 0; |
|
} |
|
|
|
static int kcore_copy__copy_file(const char *from_dir, const char *to_dir, |
|
const char *name) |
|
{ |
|
char from_filename[PATH_MAX]; |
|
char to_filename[PATH_MAX]; |
|
|
|
scnprintf(from_filename, PATH_MAX, "%s/%s", from_dir, name); |
|
scnprintf(to_filename, PATH_MAX, "%s/%s", to_dir, name); |
|
|
|
return copyfile_mode(from_filename, to_filename, 0400); |
|
} |
|
|
|
static int kcore_copy__unlink(const char *dir, const char *name) |
|
{ |
|
char filename[PATH_MAX]; |
|
|
|
scnprintf(filename, PATH_MAX, "%s/%s", dir, name); |
|
|
|
return unlink(filename); |
|
} |
|
|
|
static int kcore_copy__compare_fds(int from, int to) |
|
{ |
|
char *buf_from; |
|
char *buf_to; |
|
ssize_t ret; |
|
size_t len; |
|
int err = -1; |
|
|
|
buf_from = malloc(page_size); |
|
buf_to = malloc(page_size); |
|
if (!buf_from || !buf_to) |
|
goto out; |
|
|
|
while (1) { |
|
/* Use read because mmap won't work on proc files */ |
|
ret = read(from, buf_from, page_size); |
|
if (ret < 0) |
|
goto out; |
|
|
|
if (!ret) |
|
break; |
|
|
|
len = ret; |
|
|
|
if (readn(to, buf_to, len) != (int)len) |
|
goto out; |
|
|
|
if (memcmp(buf_from, buf_to, len)) |
|
goto out; |
|
} |
|
|
|
err = 0; |
|
out: |
|
free(buf_to); |
|
free(buf_from); |
|
return err; |
|
} |
|
|
|
static int kcore_copy__compare_files(const char *from_filename, |
|
const char *to_filename) |
|
{ |
|
int from, to, err = -1; |
|
|
|
from = open(from_filename, O_RDONLY); |
|
if (from < 0) |
|
return -1; |
|
|
|
to = open(to_filename, O_RDONLY); |
|
if (to < 0) |
|
goto out_close_from; |
|
|
|
err = kcore_copy__compare_fds(from, to); |
|
|
|
close(to); |
|
out_close_from: |
|
close(from); |
|
return err; |
|
} |
|
|
|
static int kcore_copy__compare_file(const char *from_dir, const char *to_dir, |
|
const char *name) |
|
{ |
|
char from_filename[PATH_MAX]; |
|
char to_filename[PATH_MAX]; |
|
|
|
scnprintf(from_filename, PATH_MAX, "%s/%s", from_dir, name); |
|
scnprintf(to_filename, PATH_MAX, "%s/%s", to_dir, name); |
|
|
|
return kcore_copy__compare_files(from_filename, to_filename); |
|
} |
|
|
|
/** |
|
* kcore_copy - copy kallsyms, modules and kcore from one directory to another. |
|
* @from_dir: from directory |
|
* @to_dir: to directory |
|
* |
|
* This function copies kallsyms, modules and kcore files from one directory to |
|
* another. kallsyms and modules are copied entirely. Only code segments are |
|
* copied from kcore. It is assumed that two segments suffice: one for the |
|
* kernel proper and one for all the modules. The code segments are determined |
|
* from kallsyms and modules files. The kernel map starts at _stext or the |
|
* lowest function symbol, and ends at _etext or the highest function symbol. |
|
* The module map starts at the lowest module address and ends at the highest |
|
* module symbol. Start addresses are rounded down to the nearest page. End |
|
* addresses are rounded up to the nearest page. An extra page is added to the |
|
* highest kernel symbol and highest module symbol to, hopefully, encompass that |
|
* symbol too. Because it contains only code sections, the resulting kcore is |
|
* unusual. One significant peculiarity is that the mapping (start -> pgoff) |
|
* is not the same for the kernel map and the modules map. That happens because |
|
* the data is copied adjacently whereas the original kcore has gaps. Finally, |
|
* kallsyms and modules files are compared with their copies to check that |
|
* modules have not been loaded or unloaded while the copies were taking place. |
|
* |
|
* Return: %0 on success, %-1 on failure. |
|
*/ |
|
int kcore_copy(const char *from_dir, const char *to_dir) |
|
{ |
|
struct kcore kcore; |
|
struct kcore extract; |
|
int idx = 0, err = -1; |
|
off_t offset, sz; |
|
struct kcore_copy_info kci = { .stext = 0, }; |
|
char kcore_filename[PATH_MAX]; |
|
char extract_filename[PATH_MAX]; |
|
struct phdr_data *p; |
|
|
|
INIT_LIST_HEAD(&kci.phdrs); |
|
INIT_LIST_HEAD(&kci.syms); |
|
|
|
if (kcore_copy__copy_file(from_dir, to_dir, "kallsyms")) |
|
return -1; |
|
|
|
if (kcore_copy__copy_file(from_dir, to_dir, "modules")) |
|
goto out_unlink_kallsyms; |
|
|
|
scnprintf(kcore_filename, PATH_MAX, "%s/kcore", from_dir); |
|
scnprintf(extract_filename, PATH_MAX, "%s/kcore", to_dir); |
|
|
|
if (kcore__open(&kcore, kcore_filename)) |
|
goto out_unlink_modules; |
|
|
|
if (kcore_copy__calc_maps(&kci, from_dir, kcore.elf)) |
|
goto out_kcore_close; |
|
|
|
if (kcore__init(&extract, extract_filename, kcore.elfclass, false)) |
|
goto out_kcore_close; |
|
|
|
if (kcore__copy_hdr(&kcore, &extract, kci.phnum)) |
|
goto out_extract_close; |
|
|
|
offset = gelf_fsize(extract.elf, ELF_T_EHDR, 1, EV_CURRENT) + |
|
gelf_fsize(extract.elf, ELF_T_PHDR, kci.phnum, EV_CURRENT); |
|
offset = round_up(offset, page_size); |
|
|
|
kcore_copy__for_each_phdr(&kci, p) { |
|
off_t offs = p->rel + offset; |
|
|
|
if (kcore__add_phdr(&extract, idx++, offs, p->addr, p->len)) |
|
goto out_extract_close; |
|
} |
|
|
|
sz = kcore__write(&extract); |
|
if (sz < 0 || sz > offset) |
|
goto out_extract_close; |
|
|
|
kcore_copy__for_each_phdr(&kci, p) { |
|
off_t offs = p->rel + offset; |
|
|
|
if (p->remaps) |
|
continue; |
|
if (copy_bytes(kcore.fd, p->offset, extract.fd, offs, p->len)) |
|
goto out_extract_close; |
|
} |
|
|
|
if (kcore_copy__compare_file(from_dir, to_dir, "modules")) |
|
goto out_extract_close; |
|
|
|
if (kcore_copy__compare_file(from_dir, to_dir, "kallsyms")) |
|
goto out_extract_close; |
|
|
|
err = 0; |
|
|
|
out_extract_close: |
|
kcore__close(&extract); |
|
if (err) |
|
unlink(extract_filename); |
|
out_kcore_close: |
|
kcore__close(&kcore); |
|
out_unlink_modules: |
|
if (err) |
|
kcore_copy__unlink(to_dir, "modules"); |
|
out_unlink_kallsyms: |
|
if (err) |
|
kcore_copy__unlink(to_dir, "kallsyms"); |
|
|
|
kcore_copy__free_phdrs(&kci); |
|
kcore_copy__free_syms(&kci); |
|
|
|
return err; |
|
} |
|
|
|
int kcore_extract__create(struct kcore_extract *kce) |
|
{ |
|
struct kcore kcore; |
|
struct kcore extract; |
|
size_t count = 1; |
|
int idx = 0, err = -1; |
|
off_t offset = page_size, sz; |
|
|
|
if (kcore__open(&kcore, kce->kcore_filename)) |
|
return -1; |
|
|
|
strcpy(kce->extract_filename, PERF_KCORE_EXTRACT); |
|
if (kcore__init(&extract, kce->extract_filename, kcore.elfclass, true)) |
|
goto out_kcore_close; |
|
|
|
if (kcore__copy_hdr(&kcore, &extract, count)) |
|
goto out_extract_close; |
|
|
|
if (kcore__add_phdr(&extract, idx, offset, kce->addr, kce->len)) |
|
goto out_extract_close; |
|
|
|
sz = kcore__write(&extract); |
|
if (sz < 0 || sz > offset) |
|
goto out_extract_close; |
|
|
|
if (copy_bytes(kcore.fd, kce->offs, extract.fd, offset, kce->len)) |
|
goto out_extract_close; |
|
|
|
err = 0; |
|
|
|
out_extract_close: |
|
kcore__close(&extract); |
|
if (err) |
|
unlink(kce->extract_filename); |
|
out_kcore_close: |
|
kcore__close(&kcore); |
|
|
|
return err; |
|
} |
|
|
|
void kcore_extract__delete(struct kcore_extract *kce) |
|
{ |
|
unlink(kce->extract_filename); |
|
} |
|
|
|
#ifdef HAVE_GELF_GETNOTE_SUPPORT |
|
|
|
static void sdt_adjust_loc(struct sdt_note *tmp, GElf_Addr base_off) |
|
{ |
|
if (!base_off) |
|
return; |
|
|
|
if (tmp->bit32) |
|
tmp->addr.a32[SDT_NOTE_IDX_LOC] = |
|
tmp->addr.a32[SDT_NOTE_IDX_LOC] + base_off - |
|
tmp->addr.a32[SDT_NOTE_IDX_BASE]; |
|
else |
|
tmp->addr.a64[SDT_NOTE_IDX_LOC] = |
|
tmp->addr.a64[SDT_NOTE_IDX_LOC] + base_off - |
|
tmp->addr.a64[SDT_NOTE_IDX_BASE]; |
|
} |
|
|
|
static void sdt_adjust_refctr(struct sdt_note *tmp, GElf_Addr base_addr, |
|
GElf_Addr base_off) |
|
{ |
|
if (!base_off) |
|
return; |
|
|
|
if (tmp->bit32 && tmp->addr.a32[SDT_NOTE_IDX_REFCTR]) |
|
tmp->addr.a32[SDT_NOTE_IDX_REFCTR] -= (base_addr - base_off); |
|
else if (tmp->addr.a64[SDT_NOTE_IDX_REFCTR]) |
|
tmp->addr.a64[SDT_NOTE_IDX_REFCTR] -= (base_addr - base_off); |
|
} |
|
|
|
/** |
|
* populate_sdt_note : Parse raw data and identify SDT note |
|
* @elf: elf of the opened file |
|
* @data: raw data of a section with description offset applied |
|
* @len: note description size |
|
* @type: type of the note |
|
* @sdt_notes: List to add the SDT note |
|
* |
|
* Responsible for parsing the @data in section .note.stapsdt in @elf and |
|
* if its an SDT note, it appends to @sdt_notes list. |
|
*/ |
|
static int populate_sdt_note(Elf **elf, const char *data, size_t len, |
|
struct list_head *sdt_notes) |
|
{ |
|
const char *provider, *name, *args; |
|
struct sdt_note *tmp = NULL; |
|
GElf_Ehdr ehdr; |
|
GElf_Shdr shdr; |
|
int ret = -EINVAL; |
|
|
|
union { |
|
Elf64_Addr a64[NR_ADDR]; |
|
Elf32_Addr a32[NR_ADDR]; |
|
} buf; |
|
|
|
Elf_Data dst = { |
|
.d_buf = &buf, .d_type = ELF_T_ADDR, .d_version = EV_CURRENT, |
|
.d_size = gelf_fsize((*elf), ELF_T_ADDR, NR_ADDR, EV_CURRENT), |
|
.d_off = 0, .d_align = 0 |
|
}; |
|
Elf_Data src = { |
|
.d_buf = (void *) data, .d_type = ELF_T_ADDR, |
|
.d_version = EV_CURRENT, .d_size = dst.d_size, .d_off = 0, |
|
.d_align = 0 |
|
}; |
|
|
|
tmp = (struct sdt_note *)calloc(1, sizeof(struct sdt_note)); |
|
if (!tmp) { |
|
ret = -ENOMEM; |
|
goto out_err; |
|
} |
|
|
|
INIT_LIST_HEAD(&tmp->note_list); |
|
|
|
if (len < dst.d_size + 3) |
|
goto out_free_note; |
|
|
|
/* Translation from file representation to memory representation */ |
|
if (gelf_xlatetom(*elf, &dst, &src, |
|
elf_getident(*elf, NULL)[EI_DATA]) == NULL) { |
|
pr_err("gelf_xlatetom : %s\n", elf_errmsg(-1)); |
|
goto out_free_note; |
|
} |
|
|
|
/* Populate the fields of sdt_note */ |
|
provider = data + dst.d_size; |
|
|
|
name = (const char *)memchr(provider, '\0', data + len - provider); |
|
if (name++ == NULL) |
|
goto out_free_note; |
|
|
|
tmp->provider = strdup(provider); |
|
if (!tmp->provider) { |
|
ret = -ENOMEM; |
|
goto out_free_note; |
|
} |
|
tmp->name = strdup(name); |
|
if (!tmp->name) { |
|
ret = -ENOMEM; |
|
goto out_free_prov; |
|
} |
|
|
|
args = memchr(name, '\0', data + len - name); |
|
|
|
/* |
|
* There is no argument if: |
|
* - We reached the end of the note; |
|
* - There is not enough room to hold a potential string; |
|
* - The argument string is empty or just contains ':'. |
|
*/ |
|
if (args == NULL || data + len - args < 2 || |
|
args[1] == ':' || args[1] == '\0') |
|
tmp->args = NULL; |
|
else { |
|
tmp->args = strdup(++args); |
|
if (!tmp->args) { |
|
ret = -ENOMEM; |
|
goto out_free_name; |
|
} |
|
} |
|
|
|
if (gelf_getclass(*elf) == ELFCLASS32) { |
|
memcpy(&tmp->addr, &buf, 3 * sizeof(Elf32_Addr)); |
|
tmp->bit32 = true; |
|
} else { |
|
memcpy(&tmp->addr, &buf, 3 * sizeof(Elf64_Addr)); |
|
tmp->bit32 = false; |
|
} |
|
|
|
if (!gelf_getehdr(*elf, &ehdr)) { |
|
pr_debug("%s : cannot get elf header.\n", __func__); |
|
ret = -EBADF; |
|
goto out_free_args; |
|
} |
|
|
|
/* Adjust the prelink effect : |
|
* Find out the .stapsdt.base section. |
|
* This scn will help us to handle prelinking (if present). |
|
* Compare the retrieved file offset of the base section with the |
|
* base address in the description of the SDT note. If its different, |
|
* then accordingly, adjust the note location. |
|
*/ |
|
if (elf_section_by_name(*elf, &ehdr, &shdr, SDT_BASE_SCN, NULL)) |
|
sdt_adjust_loc(tmp, shdr.sh_offset); |
|
|
|
/* Adjust reference counter offset */ |
|
if (elf_section_by_name(*elf, &ehdr, &shdr, SDT_PROBES_SCN, NULL)) |
|
sdt_adjust_refctr(tmp, shdr.sh_addr, shdr.sh_offset); |
|
|
|
list_add_tail(&tmp->note_list, sdt_notes); |
|
return 0; |
|
|
|
out_free_args: |
|
zfree(&tmp->args); |
|
out_free_name: |
|
zfree(&tmp->name); |
|
out_free_prov: |
|
zfree(&tmp->provider); |
|
out_free_note: |
|
free(tmp); |
|
out_err: |
|
return ret; |
|
} |
|
|
|
/** |
|
* construct_sdt_notes_list : constructs a list of SDT notes |
|
* @elf : elf to look into |
|
* @sdt_notes : empty list_head |
|
* |
|
* Scans the sections in 'elf' for the section |
|
* .note.stapsdt. It, then calls populate_sdt_note to find |
|
* out the SDT events and populates the 'sdt_notes'. |
|
*/ |
|
static int construct_sdt_notes_list(Elf *elf, struct list_head *sdt_notes) |
|
{ |
|
GElf_Ehdr ehdr; |
|
Elf_Scn *scn = NULL; |
|
Elf_Data *data; |
|
GElf_Shdr shdr; |
|
size_t shstrndx, next; |
|
GElf_Nhdr nhdr; |
|
size_t name_off, desc_off, offset; |
|
int ret = 0; |
|
|
|
if (gelf_getehdr(elf, &ehdr) == NULL) { |
|
ret = -EBADF; |
|
goto out_ret; |
|
} |
|
if (elf_getshdrstrndx(elf, &shstrndx) != 0) { |
|
ret = -EBADF; |
|
goto out_ret; |
|
} |
|
|
|
/* Look for the required section */ |
|
scn = elf_section_by_name(elf, &ehdr, &shdr, SDT_NOTE_SCN, NULL); |
|
if (!scn) { |
|
ret = -ENOENT; |
|
goto out_ret; |
|
} |
|
|
|
if ((shdr.sh_type != SHT_NOTE) || (shdr.sh_flags & SHF_ALLOC)) { |
|
ret = -ENOENT; |
|
goto out_ret; |
|
} |
|
|
|
data = elf_getdata(scn, NULL); |
|
|
|
/* Get the SDT notes */ |
|
for (offset = 0; (next = gelf_getnote(data, offset, &nhdr, &name_off, |
|
&desc_off)) > 0; offset = next) { |
|
if (nhdr.n_namesz == sizeof(SDT_NOTE_NAME) && |
|
!memcmp(data->d_buf + name_off, SDT_NOTE_NAME, |
|
sizeof(SDT_NOTE_NAME))) { |
|
/* Check the type of the note */ |
|
if (nhdr.n_type != SDT_NOTE_TYPE) |
|
goto out_ret; |
|
|
|
ret = populate_sdt_note(&elf, ((data->d_buf) + desc_off), |
|
nhdr.n_descsz, sdt_notes); |
|
if (ret < 0) |
|
goto out_ret; |
|
} |
|
} |
|
if (list_empty(sdt_notes)) |
|
ret = -ENOENT; |
|
|
|
out_ret: |
|
return ret; |
|
} |
|
|
|
/** |
|
* get_sdt_note_list : Wrapper to construct a list of sdt notes |
|
* @head : empty list_head |
|
* @target : file to find SDT notes from |
|
* |
|
* This opens the file, initializes |
|
* the ELF and then calls construct_sdt_notes_list. |
|
*/ |
|
int get_sdt_note_list(struct list_head *head, const char *target) |
|
{ |
|
Elf *elf; |
|
int fd, ret; |
|
|
|
fd = open(target, O_RDONLY); |
|
if (fd < 0) |
|
return -EBADF; |
|
|
|
elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL); |
|
if (!elf) { |
|
ret = -EBADF; |
|
goto out_close; |
|
} |
|
ret = construct_sdt_notes_list(elf, head); |
|
elf_end(elf); |
|
out_close: |
|
close(fd); |
|
return ret; |
|
} |
|
|
|
/** |
|
* cleanup_sdt_note_list : free the sdt notes' list |
|
* @sdt_notes: sdt notes' list |
|
* |
|
* Free up the SDT notes in @sdt_notes. |
|
* Returns the number of SDT notes free'd. |
|
*/ |
|
int cleanup_sdt_note_list(struct list_head *sdt_notes) |
|
{ |
|
struct sdt_note *tmp, *pos; |
|
int nr_free = 0; |
|
|
|
list_for_each_entry_safe(pos, tmp, sdt_notes, note_list) { |
|
list_del_init(&pos->note_list); |
|
zfree(&pos->args); |
|
zfree(&pos->name); |
|
zfree(&pos->provider); |
|
free(pos); |
|
nr_free++; |
|
} |
|
return nr_free; |
|
} |
|
|
|
/** |
|
* sdt_notes__get_count: Counts the number of sdt events |
|
* @start: list_head to sdt_notes list |
|
* |
|
* Returns the number of SDT notes in a list |
|
*/ |
|
int sdt_notes__get_count(struct list_head *start) |
|
{ |
|
struct sdt_note *sdt_ptr; |
|
int count = 0; |
|
|
|
list_for_each_entry(sdt_ptr, start, note_list) |
|
count++; |
|
return count; |
|
} |
|
#endif |
|
|
|
void symbol__elf_init(void) |
|
{ |
|
elf_version(EV_CURRENT); |
|
}
|
|
|