Ulrich Drepper | b08d5a8 | 2005-07-26 05:00:05 +0000 | [diff] [blame^] | 1 | /* Return section header. |
| 2 | Copyright (C) 1998, 1999, 2000, 2001, 2002, 2005 Red Hat, Inc. |
| 3 | Written by Ulrich Drepper <drepper@redhat.com>, 1998. |
| 4 | |
| 5 | This program is free software; you can redistribute it and/or modify |
| 6 | it under the terms of the GNU General Public License as published by |
| 7 | the Free Software Foundation, version 2. |
| 8 | |
| 9 | This program is distributed in the hope that it will be useful, |
| 10 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 11 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 12 | GNU General Public License for more details. |
| 13 | |
| 14 | You should have received a copy of the GNU General Public License |
| 15 | along with this program; if not, write to the Free Software Foundation, |
| 16 | Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ |
| 17 | |
| 18 | #ifdef HAVE_CONFIG_H |
| 19 | # include <config.h> |
| 20 | #endif |
| 21 | |
| 22 | #include <assert.h> |
| 23 | #include <unistd.h> |
| 24 | |
| 25 | #include "libelfP.h" |
| 26 | #include "common.h" |
| 27 | |
| 28 | #ifndef LIBELFBITS |
| 29 | # define LIBELFBITS 32 |
| 30 | #endif |
| 31 | |
| 32 | |
| 33 | ElfW2(LIBELFBITS,Shdr) * |
| 34 | elfw2(LIBELFBITS,getshdr) (scn) |
| 35 | Elf_Scn *scn; |
| 36 | { |
| 37 | ElfW2(LIBELFBITS,Shdr) *result; |
| 38 | |
| 39 | if (scn == NULL) |
| 40 | return NULL; |
| 41 | |
| 42 | if (unlikely (scn->elf->state.elf.ehdr == NULL)) |
| 43 | { |
| 44 | __libelf_seterrno (ELF_E_WRONG_ORDER_EHDR); |
| 45 | return NULL; |
| 46 | } |
| 47 | |
| 48 | if (unlikely (scn->elf->class != ELFW(ELFCLASS,LIBELFBITS))) |
| 49 | { |
| 50 | __libelf_seterrno (ELF_E_INVALID_CLASS); |
| 51 | return NULL; |
| 52 | } |
| 53 | |
| 54 | result = scn->shdr.ELFW(e,LIBELFBITS); |
| 55 | if (result == NULL) |
| 56 | { |
| 57 | /* Read the section header table. */ |
| 58 | Elf *elf = scn->elf; |
| 59 | ElfW2(LIBELFBITS,Ehdr) *ehdr = elf->state.ELFW(elf,LIBELFBITS).ehdr; |
| 60 | |
| 61 | rwlock_wrlock (elf->lock); |
| 62 | |
| 63 | /* Try again, maybe the data is there now. */ |
| 64 | result = scn->shdr.ELFW(e,LIBELFBITS); |
| 65 | if (result != NULL) |
| 66 | goto out; |
| 67 | |
| 68 | size_t shnum; |
| 69 | if (INTUSE (elf_getshnum) (elf, &shnum) != 0) |
| 70 | goto out; |
| 71 | size_t size = shnum * sizeof (ElfW2(LIBELFBITS,Shdr)); |
| 72 | |
| 73 | /* Allocate memory for the program headers. We know the number |
| 74 | of entries from the ELF header. */ |
| 75 | ElfW2(LIBELFBITS,Shdr) *shdr = elf->state.ELFW(elf,LIBELFBITS).shdr = |
| 76 | (ElfW2(LIBELFBITS,Shdr) *) malloc (size); |
| 77 | if (elf->state.ELFW(elf,LIBELFBITS).shdr == NULL) |
| 78 | { |
| 79 | __libelf_seterrno (ELF_E_NOMEM); |
| 80 | goto out; |
| 81 | } |
| 82 | elf->state.ELFW(elf,LIBELFBITS).shdr_malloced = 1; |
| 83 | |
| 84 | if (elf->map_address != NULL) |
| 85 | { |
| 86 | ElfW2(LIBELFBITS,Shdr) *notcvt; |
| 87 | |
| 88 | /* All the data is already mapped. If we could use it |
| 89 | directly this would already have happened. */ |
| 90 | assert (ehdr->e_ident[EI_DATA] != MY_ELFDATA |
| 91 | || (! ALLOW_UNALIGNED |
| 92 | && (ehdr->e_shoff |
| 93 | & (__alignof__ (ElfW2(LIBELFBITS,Shdr)) - 1)) != 0)); |
| 94 | |
| 95 | /* Now copy the data and at the same time convert the byte |
| 96 | order. */ |
| 97 | if (ALLOW_UNALIGNED |
| 98 | || (ehdr->e_shoff |
| 99 | & (__alignof__ (ElfW2(LIBELFBITS,Shdr)) - 1)) == 0) |
| 100 | notcvt = (ElfW2(LIBELFBITS,Shdr) *) |
| 101 | ((char *) elf->map_address |
| 102 | + elf->start_offset + ehdr->e_shoff); |
| 103 | else |
| 104 | { |
| 105 | notcvt = (ElfW2(LIBELFBITS,Shdr) *) alloca (size); |
| 106 | memcpy (notcvt, ((char *) elf->map_address |
| 107 | + elf->start_offset + ehdr->e_shoff), |
| 108 | size); |
| 109 | } |
| 110 | |
| 111 | for (size_t cnt = 0; cnt < shnum; ++cnt) |
| 112 | { |
| 113 | CONVERT_TO (shdr[cnt].sh_name, notcvt[cnt].sh_name); |
| 114 | CONVERT_TO (shdr[cnt].sh_type, notcvt[cnt].sh_type); |
| 115 | CONVERT_TO (shdr[cnt].sh_flags, notcvt[cnt].sh_flags); |
| 116 | CONVERT_TO (shdr[cnt].sh_addr, notcvt[cnt].sh_addr); |
| 117 | CONVERT_TO (shdr[cnt].sh_offset, notcvt[cnt].sh_offset); |
| 118 | CONVERT_TO (shdr[cnt].sh_size, notcvt[cnt].sh_size); |
| 119 | CONVERT_TO (shdr[cnt].sh_link, notcvt[cnt].sh_link); |
| 120 | CONVERT_TO (shdr[cnt].sh_info, notcvt[cnt].sh_info); |
| 121 | CONVERT_TO (shdr[cnt].sh_addralign, notcvt[cnt].sh_addralign); |
| 122 | CONVERT_TO (shdr[cnt].sh_entsize, notcvt[cnt].sh_entsize); |
| 123 | } |
| 124 | } |
| 125 | else if (elf->fildes != -1) |
| 126 | { |
| 127 | /* Read the header. */ |
| 128 | if ((size_t) pread (elf->fildes, |
| 129 | elf->state.ELFW(elf,LIBELFBITS).shdr, size, |
| 130 | elf->start_offset + ehdr->e_shoff) != size) |
| 131 | { |
| 132 | /* Severe problems. We cannot read the data. */ |
| 133 | __libelf_seterrno (ELF_E_READ_ERROR); |
| 134 | goto free_and_out; |
| 135 | } |
| 136 | |
| 137 | /* If the byte order of the file is not the same as the one |
| 138 | of the host convert the data now. */ |
| 139 | if (ehdr->e_ident[EI_DATA] != MY_ELFDATA) |
| 140 | for (size_t cnt = 0; cnt < shnum; ++cnt) |
| 141 | { |
| 142 | CONVERT (shdr[cnt].sh_name); |
| 143 | CONVERT (shdr[cnt].sh_type); |
| 144 | CONVERT (shdr[cnt].sh_flags); |
| 145 | CONVERT (shdr[cnt].sh_addr); |
| 146 | CONVERT (shdr[cnt].sh_offset); |
| 147 | CONVERT (shdr[cnt].sh_size); |
| 148 | CONVERT (shdr[cnt].sh_link); |
| 149 | CONVERT (shdr[cnt].sh_info); |
| 150 | CONVERT (shdr[cnt].sh_addralign); |
| 151 | CONVERT (shdr[cnt].sh_entsize); |
| 152 | } |
| 153 | } |
| 154 | else |
| 155 | { |
| 156 | /* The file descriptor was already enabled and not all data was |
| 157 | read. Undo the allocation. */ |
| 158 | __libelf_seterrno (ELF_E_FD_DISABLED); |
| 159 | |
| 160 | free_and_out: |
| 161 | free (shdr); |
| 162 | elf->state.ELFW(elf,LIBELFBITS).shdr = NULL; |
| 163 | elf->state.ELFW(elf,LIBELFBITS).shdr_malloced = 0; |
| 164 | |
| 165 | goto out; |
| 166 | } |
| 167 | |
| 168 | /* Set the pointers in the `scn's. */ |
| 169 | for (size_t cnt = 0; cnt < shnum; ++cnt) |
| 170 | elf->state.ELFW(elf,LIBELFBITS).scns.data[cnt].shdr.ELFW(e,LIBELFBITS) |
| 171 | = &elf->state.ELFW(elf,LIBELFBITS).shdr[cnt]; |
| 172 | |
| 173 | result = scn->shdr.ELFW(e,LIBELFBITS); |
| 174 | assert (result != NULL); |
| 175 | |
| 176 | out: |
| 177 | rwlock_unlock (elf->lock); |
| 178 | } |
| 179 | |
| 180 | return result; |
| 181 | } |
| 182 | INTDEF(elfw2(LIBELFBITS,getshdr)) |