Ulrich Drepper | b08d5a8 | 2005-07-26 05:00:05 +0000 | [diff] [blame] | 1 | /* Extract symbol list from binary. |
Ulrich Drepper | 66c650e | 2007-01-30 16:48:56 +0000 | [diff] [blame] | 2 | Copyright (C) 1998, 1999, 2000, 2001, 2002, 2005, 2007 Red Hat, Inc. |
Ulrich Drepper | 361df7d | 2006-04-04 21:38:57 +0000 | [diff] [blame] | 3 | This file is part of Red Hat elfutils. |
Ulrich Drepper | b08d5a8 | 2005-07-26 05:00:05 +0000 | [diff] [blame] | 4 | Written by Ulrich Drepper <drepper@redhat.com>, 1998. |
| 5 | |
Ulrich Drepper | 361df7d | 2006-04-04 21:38:57 +0000 | [diff] [blame] | 6 | Red Hat elfutils is free software; you can redistribute it and/or modify |
| 7 | it under the terms of the GNU General Public License as published by the |
| 8 | Free Software Foundation; version 2 of the License. |
Ulrich Drepper | b08d5a8 | 2005-07-26 05:00:05 +0000 | [diff] [blame] | 9 | |
Ulrich Drepper | 361df7d | 2006-04-04 21:38:57 +0000 | [diff] [blame] | 10 | Red Hat elfutils is distributed in the hope that it will be useful, but |
| 11 | WITHOUT ANY WARRANTY; without even the implied warranty of |
| 12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 13 | General Public License for more details. |
Ulrich Drepper | b08d5a8 | 2005-07-26 05:00:05 +0000 | [diff] [blame] | 14 | |
Ulrich Drepper | 361df7d | 2006-04-04 21:38:57 +0000 | [diff] [blame] | 15 | You should have received a copy of the GNU General Public License along |
| 16 | with Red Hat elfutils; if not, write to the Free Software Foundation, |
Ulrich Drepper | 1e9ef50 | 2006-04-04 22:29:06 +0000 | [diff] [blame] | 17 | Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301 USA. |
Ulrich Drepper | 361df7d | 2006-04-04 21:38:57 +0000 | [diff] [blame] | 18 | |
| 19 | In addition, as a special exception, Red Hat, Inc. gives You the |
| 20 | additional right to link the code of Red Hat elfutils with code licensed |
| 21 | under any Open Source Initiative certified open source license |
| 22 | (http://www.opensource.org/licenses/index.php) which requires the |
| 23 | distribution of source code with any binary distribution and to |
| 24 | distribute linked combinations of the two. Non-GPL Code permitted under |
| 25 | this exception must only link to the code of Red Hat elfutils through |
| 26 | those well defined interfaces identified in the file named EXCEPTION |
| 27 | found in the source code files (the "Approved Interfaces"). The files |
| 28 | of Non-GPL Code may instantiate templates or use macros or inline |
| 29 | functions from the Approved Interfaces without causing the resulting |
| 30 | work to be covered by the GNU General Public License. Only Red Hat, |
| 31 | Inc. may make changes or additions to the list of Approved Interfaces. |
| 32 | Red Hat's grant of this exception is conditioned upon your not adding |
| 33 | any new exceptions. If you wish to add a new Approved Interface or |
| 34 | exception, please contact Red Hat. You must obey the GNU General Public |
| 35 | License in all respects for all of the Red Hat elfutils code and other |
| 36 | code used in conjunction with Red Hat elfutils except the Non-GPL Code |
| 37 | covered by this exception. If you modify this file, you may extend this |
| 38 | exception to your version of the file, but you are not obligated to do |
| 39 | so. If you do not wish to provide this exception without modification, |
| 40 | you must delete this exception statement from your version and license |
| 41 | this file solely under the GPL without exception. |
| 42 | |
| 43 | Red Hat elfutils is an included package of the Open Invention Network. |
| 44 | An included package of the Open Invention Network is a package for which |
| 45 | Open Invention Network licensees cross-license their patents. No patent |
| 46 | license is granted, either expressly or impliedly, by designation as an |
| 47 | included package. Should you wish to participate in the Open Invention |
| 48 | Network licensing program, please visit www.openinventionnetwork.com |
| 49 | <http://www.openinventionnetwork.com>. */ |
Ulrich Drepper | b08d5a8 | 2005-07-26 05:00:05 +0000 | [diff] [blame] | 50 | |
| 51 | #ifdef HAVE_CONFIG_H |
| 52 | # include <config.h> |
| 53 | #endif |
| 54 | |
| 55 | #include <fcntl.h> |
| 56 | #include <gelf.h> |
| 57 | #include <libelf.h> |
| 58 | #include <nlist.h> |
| 59 | #include <unistd.h> |
| 60 | |
| 61 | #include "libelfP.h" |
| 62 | |
| 63 | |
| 64 | struct hashentry |
| 65 | { |
| 66 | const char *str; |
| 67 | GElf_Sym sym; |
| 68 | }; |
| 69 | #define TYPE struct hashentry |
| 70 | /* XXX Use a better hash function some day. */ |
| 71 | #define HASHFCT(str, len) INTUSE(elf_hash) (str) |
| 72 | #define COMPARE(p1, p2) strcmp ((p1)->str, (p2)->str) |
| 73 | #define CLASS static |
| 74 | #define PREFIX nlist_ |
| 75 | #define xcalloc(n, m) calloc (n, m) |
| 76 | #define next_prime(s) __libelf_next_prime (s) |
| 77 | #include <fixedsizehash.h> |
| 78 | |
| 79 | |
| 80 | int |
| 81 | nlist (const char *filename, struct nlist *nl) |
| 82 | { |
| 83 | int fd; |
| 84 | Elf *elf; |
| 85 | Elf_Scn *scn = NULL; |
| 86 | Elf_Scn *symscn = NULL; |
| 87 | GElf_Shdr shdr_mem; |
| 88 | GElf_Shdr *shdr = NULL; |
| 89 | Elf_Data *data; |
| 90 | struct nlist_fshash *table; |
| 91 | size_t nsyms; |
| 92 | size_t cnt; |
| 93 | |
| 94 | /* Open the file. */ |
| 95 | fd = open (filename, O_RDONLY); |
| 96 | if (fd == -1) |
| 97 | { |
| 98 | __libelf_seterrno (ELF_E_NOFILE); |
| 99 | goto fail; |
| 100 | } |
| 101 | |
| 102 | /* For compatibility reasons (`nlist' existed before ELF and libelf) |
| 103 | we don't expect the caller to set the ELF version. Do this here |
| 104 | if it hasn't happened yet. */ |
| 105 | if (__libelf_version_initialized == 0) |
| 106 | INTUSE(elf_version) (EV_CURRENT); |
| 107 | |
| 108 | /* Now get an ELF descriptor. */ |
| 109 | elf = INTUSE(elf_begin) (fd, ELF_C_READ_MMAP, NULL); |
| 110 | if (elf == NULL) |
Ulrich Drepper | cd8a250 | 2007-01-30 16:51:59 +0000 | [diff] [blame] | 111 | goto fail_fd; |
Ulrich Drepper | b08d5a8 | 2005-07-26 05:00:05 +0000 | [diff] [blame] | 112 | |
| 113 | /* Find a symbol table. We prefer the real symbol table but if it |
| 114 | does not exist use the dynamic symbol table. */ |
| 115 | while ((scn = INTUSE(elf_nextscn) (elf, scn)) != NULL) |
| 116 | { |
| 117 | shdr = INTUSE(gelf_getshdr) (scn, &shdr_mem); |
| 118 | if (shdr == NULL) |
| 119 | goto fail_close; |
| 120 | |
| 121 | /* That is what we are looking for. */ |
| 122 | if (shdr->sh_type == SHT_SYMTAB) |
| 123 | { |
| 124 | symscn = scn; |
| 125 | break; |
| 126 | } |
| 127 | |
| 128 | /* Better than nothing. Remember this section. */ |
| 129 | if (shdr->sh_type == SHT_DYNSYM) |
| 130 | symscn = scn; |
| 131 | } |
| 132 | |
| 133 | if (symscn == NULL) |
| 134 | /* We haven't found anything. Fail. */ |
| 135 | goto fail_close; |
| 136 | |
| 137 | /* Re-get the section header in case we found only the dynamic symbol |
| 138 | table. */ |
| 139 | if (scn == NULL) |
| 140 | shdr = INTUSE(gelf_getshdr) (symscn, &shdr_mem); |
| 141 | /* SHDR->SH_LINK now contains the index of the string section. */ |
| 142 | |
| 143 | /* Get the data for the symbol section. */ |
Roland McGrath | b4d6f0f | 2008-08-25 22:55:17 +0000 | [diff] [blame] | 144 | data = INTUSE(elf_getdata) (symscn, NULL); |
Ulrich Drepper | b08d5a8 | 2005-07-26 05:00:05 +0000 | [diff] [blame] | 145 | if (data == NULL) |
| 146 | goto fail_close; |
| 147 | |
| 148 | /* How many symbols are there? */ |
| 149 | nsyms = (shdr->sh_size |
| 150 | / INTUSE(gelf_fsize) (elf, ELF_T_SYM, 1, data->d_version)); |
| 151 | |
| 152 | /* Create the hash table. */ |
| 153 | table = nlist_fshash_init (nsyms); |
| 154 | if (table == NULL) |
| 155 | { |
| 156 | __libelf_seterrno (ELF_E_NOMEM); |
| 157 | goto fail_close; |
| 158 | } |
| 159 | |
| 160 | /* Iterate over all the symbols in the section. */ |
| 161 | for (cnt = 0; cnt < nsyms; ++cnt) |
| 162 | { |
| 163 | struct hashentry mem; |
| 164 | GElf_Sym *sym; |
| 165 | |
| 166 | /* Get the symbol. */ |
| 167 | sym = INTUSE(gelf_getsym) (data, cnt, &mem.sym); |
| 168 | if (sym == NULL) |
| 169 | goto fail_dealloc; |
| 170 | |
| 171 | /* Get the name of the symbol. */ |
| 172 | mem.str = INTUSE(elf_strptr) (elf, shdr->sh_link, sym->st_name); |
| 173 | if (mem.str == NULL) |
| 174 | goto fail_dealloc; |
| 175 | |
| 176 | /* Don't allow zero-length strings. */ |
| 177 | if (mem.str[0] == '\0') |
| 178 | continue; |
| 179 | |
| 180 | /* And add it to the hash table. Note that we are using the |
| 181 | overwrite version. This will ensure that |
| 182 | a) global symbols are preferred over local symbols since |
| 183 | they are all located at the end |
| 184 | b) if there are multiple local symbols with the same name |
| 185 | the last one is used. |
| 186 | */ |
| 187 | (void) nlist_fshash_overwrite (table, mem.str, 0, &mem); |
| 188 | } |
| 189 | |
| 190 | /* Now it is time to look for the symbols the user asked for. |
| 191 | XXX What is a `null name/null string'? This is what the |
| 192 | standard says terminates the list. Is it a null pointer |
| 193 | or a zero-length string? We test for both... */ |
| 194 | while (nl->n_name != NULL && nl->n_name[0] != '\0') |
| 195 | { |
| 196 | struct hashentry search; |
| 197 | const struct hashentry *found; |
| 198 | |
| 199 | /* Search for a matching entry in the hash table. */ |
| 200 | search.str = nl->n_name; |
| 201 | found = nlist_fshash_find (table, nl->n_name, 0, &search); |
| 202 | |
| 203 | if (found != NULL) |
| 204 | { |
| 205 | /* Found it. */ |
| 206 | nl->n_value = found->sym.st_value; |
| 207 | nl->n_scnum = found->sym.st_shndx; |
| 208 | nl->n_type = GELF_ST_TYPE (found->sym.st_info); |
| 209 | /* XXX What shall we fill in the next fields? */ |
| 210 | nl->n_sclass = 0; |
| 211 | nl->n_numaux = 0; |
| 212 | } |
| 213 | else |
| 214 | { |
| 215 | /* Not there. */ |
| 216 | nl->n_value = 0; |
| 217 | nl->n_scnum = 0; |
| 218 | nl->n_type = 0; |
| 219 | nl->n_sclass = 0; |
| 220 | nl->n_numaux = 0; |
| 221 | } |
| 222 | |
| 223 | /* Next search request. */ |
| 224 | ++nl; |
| 225 | } |
| 226 | |
| 227 | /* Free the resources. */ |
| 228 | nlist_fshash_fini (table); |
| 229 | |
| 230 | /* We do not need the ELF descriptor anymore. */ |
| 231 | (void) INTUSE(elf_end) (elf); |
| 232 | |
Ulrich Drepper | ecf2b12 | 2007-01-30 16:19:09 +0000 | [diff] [blame] | 233 | /* Neither the file descriptor. */ |
| 234 | (void) close (fd); |
| 235 | |
Ulrich Drepper | b08d5a8 | 2005-07-26 05:00:05 +0000 | [diff] [blame] | 236 | return 0; |
| 237 | |
| 238 | fail_dealloc: |
| 239 | nlist_fshash_fini (table); |
| 240 | |
| 241 | fail_close: |
| 242 | /* We do not need the ELF descriptor anymore. */ |
| 243 | (void) INTUSE(elf_end) (elf); |
| 244 | |
Ulrich Drepper | cd8a250 | 2007-01-30 16:51:59 +0000 | [diff] [blame] | 245 | fail_fd: |
Ulrich Drepper | ecf2b12 | 2007-01-30 16:19:09 +0000 | [diff] [blame] | 246 | /* Neither the file descriptor. */ |
| 247 | (void) close (fd); |
| 248 | |
Ulrich Drepper | b08d5a8 | 2005-07-26 05:00:05 +0000 | [diff] [blame] | 249 | fail: |
| 250 | /* We have to set all entries to zero. */ |
| 251 | while (nl->n_name != NULL && nl->n_name[0] != '\0') |
| 252 | { |
| 253 | nl->n_value = 0; |
| 254 | nl->n_scnum = 0; |
| 255 | nl->n_type = 0; |
| 256 | nl->n_sclass = 0; |
| 257 | nl->n_numaux = 0; |
| 258 | |
| 259 | /* Next entry. */ |
| 260 | ++nl; |
| 261 | } |
| 262 | |
| 263 | return -1; |
| 264 | } |