mostang.com!davidm | 824d661 | 2003-02-08 10:10:59 +0000 | [diff] [blame] | 1 | /* libunwind - a platform-independent unwind library |
| 2 | Copyright (C) 2003 Hewlett-Packard Co |
| 3 | Contributed by David Mosberger-Tang <davidm@hpl.hp.com> |
| 4 | |
| 5 | This file is part of libunwind. |
| 6 | |
| 7 | Permission is hereby granted, free of charge, to any person obtaining |
| 8 | a copy of this software and associated documentation files (the |
| 9 | "Software"), to deal in the Software without restriction, including |
| 10 | without limitation the rights to use, copy, modify, merge, publish, |
| 11 | distribute, sublicense, and/or sell copies of the Software, and to |
| 12 | permit persons to whom the Software is furnished to do so, subject to |
| 13 | the following conditions: |
| 14 | |
| 15 | The above copyright notice and this permission notice shall be |
| 16 | included in all copies or substantial portions of the Software. |
| 17 | |
| 18 | THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, |
| 19 | EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF |
| 20 | MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND |
| 21 | NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE |
| 22 | LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION |
| 23 | OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION |
| 24 | WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */ |
| 25 | |
| 26 | #include <stdio.h> |
| 27 | #include <string.h> |
| 28 | #include <unistd.h> |
| 29 | |
| 30 | #include <sys/types.h> |
| 31 | |
| 32 | |
| 33 | extern HIDDEN int |
| 34 | elfW (valid_object) (struct elf_image *ei) |
| 35 | { |
| 36 | if (ei->size <= EI_CLASS) |
| 37 | return 0; |
| 38 | |
| 39 | return (memcmp (ei->image, ELFMAG, SELFMAG) == 0 |
| 40 | && ((uint8_t *) ei->image)[EI_CLASS] == ELF_CLASS); |
| 41 | } |
| 42 | |
| 43 | |
| 44 | static int |
| 45 | elfW (lookup_symbol) (unw_word_t ip, struct elf_image *ei, |
| 46 | ElfW (Addr) load_offset, |
| 47 | char *buf, size_t buf_len, unw_word_t *offp) |
| 48 | { |
| 49 | size_t syment_size, str_size; |
| 50 | ElfW (Ehdr) *ehdr = ei->image; |
| 51 | ElfW (Sym) *sym, *symtab, *symtab_end; |
| 52 | ElfW (Off) soff, str_soff; |
| 53 | ElfW (Shdr) *shdr, *str_shdr; |
| 54 | ElfW (Addr) val, min_dist = ~(ElfW (Addr))0; |
| 55 | char *strtab; |
| 56 | int i; |
| 57 | |
| 58 | if (!elfW (valid_object) (ei)) |
| 59 | return -1; |
| 60 | |
| 61 | soff = ehdr->e_shoff; |
| 62 | if (soff + ehdr->e_shnum * ehdr->e_shentsize > ei->size) |
| 63 | { |
| 64 | debug (1, "%s: section table outside of image? (%lu > %lu)\n", |
| 65 | __FUNCTION__, soff + ehdr->e_shnum * ehdr->e_shentsize, |
| 66 | ei->size); |
| 67 | return -1; |
| 68 | } |
| 69 | |
| 70 | shdr = (ElfW (Shdr) *) ((char *) ei->image + soff); |
| 71 | |
| 72 | for (i = 0; i < ehdr->e_shnum; ++i) |
| 73 | { |
| 74 | switch (shdr->sh_type) |
| 75 | { |
| 76 | case SHT_SYMTAB: |
| 77 | case SHT_DYNSYM: |
| 78 | symtab = (ElfW (Sym) *) ((char *) ei->image + shdr->sh_offset); |
| 79 | symtab_end = (ElfW (Sym) *) ((char *) symtab + shdr->sh_size); |
| 80 | syment_size = shdr->sh_entsize; |
| 81 | |
| 82 | str_soff = soff + (shdr->sh_link * ehdr->e_shentsize); |
| 83 | if (str_soff + ehdr->e_shentsize >= ei->size) |
| 84 | { |
| 85 | debug (1, "%s: string table outside of image? (%lu >= %lu)\n", |
| 86 | __FUNCTION__, str_soff + ehdr->e_shentsize, ei->size); |
| 87 | break; |
| 88 | } |
| 89 | str_shdr = (ElfW (Shdr) *) ((char *) ei->image + str_soff); |
| 90 | str_size = str_shdr->sh_size; |
| 91 | strtab = (char *) ei->image + str_shdr->sh_offset; |
| 92 | |
| 93 | debug (10, "symtab=0x%lx[%d], strtab=0x%lx\n", shdr->sh_offset, |
| 94 | shdr->sh_type, str_shdr->sh_offset); |
| 95 | |
| 96 | for (sym = symtab; |
| 97 | sym < symtab_end; |
| 98 | sym = (ElfW (Sym) *) ((char *) sym + syment_size)) |
| 99 | { |
| 100 | if (ELFW (ST_TYPE) (sym->st_info) == STT_FUNC |
| 101 | && sym->st_shndx != SHN_UNDEF) |
| 102 | { |
| 103 | val = sym->st_value; |
| 104 | if (sym->st_shndx != SHN_ABS) |
| 105 | val += load_offset; |
| 106 | debug (100, "0x%016lx info=0x%02x %s\n", |
| 107 | val, sym->st_info, strtab + sym->st_name); |
| 108 | |
| 109 | if ((ElfW (Addr)) (ip - val) < min_dist) |
| 110 | { |
| 111 | min_dist = (ElfW (Addr)) (ip - val); |
| 112 | buf[buf_len - 1] = 'x'; |
| 113 | strncpy (buf, strtab + sym->st_name, buf_len); |
| 114 | buf[buf_len - 1] = '\0'; |
| 115 | } |
| 116 | } |
| 117 | } |
| 118 | break; |
| 119 | |
| 120 | default: |
| 121 | break; |
| 122 | } |
| 123 | shdr = (Elf64_Shdr *) (((char *) shdr) + ehdr->e_shentsize); |
| 124 | } |
| 125 | if (min_dist >= ei->size) |
| 126 | return -1; /* not found */ |
| 127 | if (offp) |
| 128 | *offp = min_dist; |
| 129 | return 0; |
| 130 | } |
| 131 | |
| 132 | /* Find the ELF image that contains IP and return the "closest" |
| 133 | procedure name, if there is one. With some caching, this could be |
| 134 | sped up greatly, but until an application materializes that's |
| 135 | sensitive to the performance of this routine, why bother... */ |
| 136 | |
| 137 | HIDDEN int |
| 138 | elfW (get_proc_name) (unw_word_t ip, char *buf, size_t buf_len, |
| 139 | unw_word_t *offp) |
| 140 | { |
| 141 | unsigned long segbase, mapoff; |
| 142 | ElfW (Addr) load_offset = 0; |
| 143 | struct elf_image ei; |
| 144 | ElfW (Ehdr) *ehdr; |
| 145 | ElfW (Phdr) *phdr; |
| 146 | int i, ret; |
| 147 | |
| 148 | ret = tdep_get_elf_image (&ei, getpid (), ip, &segbase, &mapoff); |
| 149 | if (ret < 0) |
| 150 | return ret; |
| 151 | |
| 152 | ehdr = ei.image; |
| 153 | phdr = (Elf64_Phdr *) ((char *) ei.image + ehdr->e_phoff); |
| 154 | |
| 155 | for (i = 0; i < ehdr->e_phnum; ++i) |
| 156 | if (phdr[i].p_type == PT_LOAD && phdr[i].p_offset == mapoff) |
| 157 | { |
| 158 | load_offset = segbase - phdr[i].p_vaddr; |
| 159 | break; |
| 160 | } |
| 161 | |
| 162 | ret = elfW (lookup_symbol) (ip, &ei, load_offset, buf, buf_len, offp); |
| 163 | |
| 164 | munmap (ei.image, ei.size); |
| 165 | ei.image = NULL; |
| 166 | |
| 167 | return ret; |
| 168 | } |