diff options
Diffstat (limited to 'libelf/elf32_getshdr.c')
| -rw-r--r-- | libelf/elf32_getshdr.c | 182 |
1 files changed, 182 insertions, 0 deletions
diff --git a/libelf/elf32_getshdr.c b/libelf/elf32_getshdr.c new file mode 100644 index 00000000..1e26e854 --- /dev/null +++ b/libelf/elf32_getshdr.c @@ -0,0 +1,182 @@ +/* Return section header. + Copyright (C) 1998, 1999, 2000, 2001, 2002, 2005 Red Hat, Inc. + Written by Ulrich Drepper <drepper@redhat.com>, 1998. + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation, version 2. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the Free Software Foundation, + Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ + +#ifdef HAVE_CONFIG_H +# include <config.h> +#endif + +#include <assert.h> +#include <unistd.h> + +#include "libelfP.h" +#include "common.h" + +#ifndef LIBELFBITS +# define LIBELFBITS 32 +#endif + + +ElfW2(LIBELFBITS,Shdr) * +elfw2(LIBELFBITS,getshdr) (scn) + Elf_Scn *scn; +{ + ElfW2(LIBELFBITS,Shdr) *result; + + if (scn == NULL) + return NULL; + + if (unlikely (scn->elf->state.elf.ehdr == NULL)) + { + __libelf_seterrno (ELF_E_WRONG_ORDER_EHDR); + return NULL; + } + + if (unlikely (scn->elf->class != ELFW(ELFCLASS,LIBELFBITS))) + { + __libelf_seterrno (ELF_E_INVALID_CLASS); + return NULL; + } + + result = scn->shdr.ELFW(e,LIBELFBITS); + if (result == NULL) + { + /* Read the section header table. */ + Elf *elf = scn->elf; + ElfW2(LIBELFBITS,Ehdr) *ehdr = elf->state.ELFW(elf,LIBELFBITS).ehdr; + + rwlock_wrlock (elf->lock); + + /* Try again, maybe the data is there now. */ + result = scn->shdr.ELFW(e,LIBELFBITS); + if (result != NULL) + goto out; + + size_t shnum; + if (INTUSE (elf_getshnum) (elf, &shnum) != 0) + goto out; + size_t size = shnum * sizeof (ElfW2(LIBELFBITS,Shdr)); + + /* Allocate memory for the program headers. We know the number + of entries from the ELF header. */ + ElfW2(LIBELFBITS,Shdr) *shdr = elf->state.ELFW(elf,LIBELFBITS).shdr = + (ElfW2(LIBELFBITS,Shdr) *) malloc (size); + if (elf->state.ELFW(elf,LIBELFBITS).shdr == NULL) + { + __libelf_seterrno (ELF_E_NOMEM); + goto out; + } + elf->state.ELFW(elf,LIBELFBITS).shdr_malloced = 1; + + if (elf->map_address != NULL) + { + ElfW2(LIBELFBITS,Shdr) *notcvt; + + /* All the data is already mapped. If we could use it + directly this would already have happened. */ + assert (ehdr->e_ident[EI_DATA] != MY_ELFDATA + || (! ALLOW_UNALIGNED + && (ehdr->e_shoff + & (__alignof__ (ElfW2(LIBELFBITS,Shdr)) - 1)) != 0)); + + /* Now copy the data and at the same time convert the byte + order. */ + if (ALLOW_UNALIGNED + || (ehdr->e_shoff + & (__alignof__ (ElfW2(LIBELFBITS,Shdr)) - 1)) == 0) + notcvt = (ElfW2(LIBELFBITS,Shdr) *) + ((char *) elf->map_address + + elf->start_offset + ehdr->e_shoff); + else + { + notcvt = (ElfW2(LIBELFBITS,Shdr) *) alloca (size); + memcpy (notcvt, ((char *) elf->map_address + + elf->start_offset + ehdr->e_shoff), + size); + } + + for (size_t cnt = 0; cnt < shnum; ++cnt) + { + CONVERT_TO (shdr[cnt].sh_name, notcvt[cnt].sh_name); + CONVERT_TO (shdr[cnt].sh_type, notcvt[cnt].sh_type); + CONVERT_TO (shdr[cnt].sh_flags, notcvt[cnt].sh_flags); + CONVERT_TO (shdr[cnt].sh_addr, notcvt[cnt].sh_addr); + CONVERT_TO (shdr[cnt].sh_offset, notcvt[cnt].sh_offset); + CONVERT_TO (shdr[cnt].sh_size, notcvt[cnt].sh_size); + CONVERT_TO (shdr[cnt].sh_link, notcvt[cnt].sh_link); + CONVERT_TO (shdr[cnt].sh_info, notcvt[cnt].sh_info); + CONVERT_TO (shdr[cnt].sh_addralign, notcvt[cnt].sh_addralign); + CONVERT_TO (shdr[cnt].sh_entsize, notcvt[cnt].sh_entsize); + } + } + else if (elf->fildes != -1) + { + /* Read the header. */ + if ((size_t) pread (elf->fildes, + elf->state.ELFW(elf,LIBELFBITS).shdr, size, + elf->start_offset + ehdr->e_shoff) != size) + { + /* Severe problems. We cannot read the data. */ + __libelf_seterrno (ELF_E_READ_ERROR); + goto free_and_out; + } + + /* If the byte order of the file is not the same as the one + of the host convert the data now. */ + if (ehdr->e_ident[EI_DATA] != MY_ELFDATA) + for (size_t cnt = 0; cnt < shnum; ++cnt) + { + CONVERT (shdr[cnt].sh_name); + CONVERT (shdr[cnt].sh_type); + CONVERT (shdr[cnt].sh_flags); + CONVERT (shdr[cnt].sh_addr); + CONVERT (shdr[cnt].sh_offset); + CONVERT (shdr[cnt].sh_size); + CONVERT (shdr[cnt].sh_link); + CONVERT (shdr[cnt].sh_info); + CONVERT (shdr[cnt].sh_addralign); + CONVERT (shdr[cnt].sh_entsize); + } + } + else + { + /* The file descriptor was already enabled and not all data was + read. Undo the allocation. */ + __libelf_seterrno (ELF_E_FD_DISABLED); + + free_and_out: + free (shdr); + elf->state.ELFW(elf,LIBELFBITS).shdr = NULL; + elf->state.ELFW(elf,LIBELFBITS).shdr_malloced = 0; + + goto out; + } + + /* Set the pointers in the `scn's. */ + for (size_t cnt = 0; cnt < shnum; ++cnt) + elf->state.ELFW(elf,LIBELFBITS).scns.data[cnt].shdr.ELFW(e,LIBELFBITS) + = &elf->state.ELFW(elf,LIBELFBITS).shdr[cnt]; + + result = scn->shdr.ELFW(e,LIBELFBITS); + assert (result != NULL); + + out: + rwlock_unlock (elf->lock); + } + + return result; +} +INTDEF(elfw2(LIBELFBITS,getshdr)) |