diff options
Diffstat (limited to 'libelf/elf_getdata_rawchunk.c')
| -rw-r--r-- | libelf/elf_getdata_rawchunk.c | 177 |
1 files changed, 177 insertions, 0 deletions
diff --git a/libelf/elf_getdata_rawchunk.c b/libelf/elf_getdata_rawchunk.c new file mode 100644 index 00000000..63a9914f --- /dev/null +++ b/libelf/elf_getdata_rawchunk.c @@ -0,0 +1,177 @@ +/* Return converted data from raw chunk of ELF file. + Copyright (C) 2007, 2014 Red Hat, Inc. + This file is part of elfutils. + + This file is free software; you can redistribute it and/or modify + it under the terms of either + + * the GNU Lesser General Public License as published by the Free + Software Foundation; either version 3 of the License, or (at + your option) any later version + + or + + * the GNU General Public License as published by the Free + Software Foundation; either version 2 of the License, or (at + your option) any later version + + or both in parallel, as here. + + elfutils 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 copies of the GNU General Public License and + the GNU Lesser General Public License along with this program. If + not, see <http://www.gnu.org/licenses/>. */ + +#ifdef HAVE_CONFIG_H +# include <config.h> +#endif + +#include <assert.h> +#include <errno.h> +#include <stdlib.h> +#include <string.h> +#include <unistd.h> + +#include <system.h> +#include "libelfP.h" +#include "common.h" + +Elf_Data * +elf_getdata_rawchunk (elf, offset, size, type) + Elf *elf; + off64_t offset; + size_t size; + Elf_Type type; +{ + if (unlikely (elf == NULL)) + return NULL; + + if (unlikely (elf->kind != ELF_K_ELF)) + { + /* No valid descriptor. */ + __libelf_seterrno (ELF_E_INVALID_HANDLE); + return NULL; + } + + if (unlikely (offset < 0 || (uint64_t) offset > elf->maximum_size + || elf->maximum_size - (uint64_t) offset < size)) + + { + /* Invalid request. */ + __libelf_seterrno (ELF_E_INVALID_OP); + return NULL; + } + + if (type >= ELF_T_NUM) + { + __libelf_seterrno (ELF_E_UNKNOWN_TYPE); + return NULL; + } + + /* Get the raw bytes from the file. */ + void *rawchunk; + int flags = 0; + Elf_Data *result = NULL; + + rwlock_rdlock (elf->lock); + + /* If the file is mmap'ed we can use it directly. */ + if (elf->map_address != NULL) + rawchunk = elf->map_address + elf->start_offset + offset; + else + { + /* We allocate the memory and read the data from the file. */ + rawchunk = malloc (size); + if (rawchunk == NULL) + { + nomem: + __libelf_seterrno (ELF_E_NOMEM); + goto out; + } + + /* Read the file content. */ + if (unlikely ((size_t) pread_retry (elf->fildes, rawchunk, size, + elf->start_offset + offset) + != size)) + { + /* Something went wrong. */ + free (rawchunk); + __libelf_seterrno (ELF_E_READ_ERROR); + goto out; + } + + flags = ELF_F_MALLOCED; + } + + /* Copy and/or convert the data as needed for aligned native-order access. */ + size_t align = __libelf_type_align (elf->class, type); + void *buffer; + if (elf->state.elf32.ehdr->e_ident[EI_DATA] == MY_ELFDATA) + { + if (((uintptr_t) rawchunk & (align - 1)) == 0) + /* No need to copy, we can use the raw data. */ + buffer = rawchunk; + else + { + /* A malloc'd block is always sufficiently aligned. */ + assert (flags == 0); + + buffer = malloc (size); + if (unlikely (buffer == NULL)) + goto nomem; + flags = ELF_F_MALLOCED; + + /* The copy will be appropriately aligned for direct access. */ + memcpy (buffer, rawchunk, size); + } + } + else + { + if (flags) + buffer = rawchunk; + else + { + buffer = malloc (size); + if (unlikely (buffer == NULL)) + goto nomem; + flags = ELF_F_MALLOCED; + } + + /* Call the conversion function. */ + (*__elf_xfctstom[LIBELF_EV_IDX][LIBELF_EV_IDX][elf->class - 1][type]) + (buffer, rawchunk, size, 0); + } + + /* Allocate the dummy container to point at this buffer. */ + Elf_Data_Chunk *chunk = calloc (1, sizeof *chunk); + if (chunk == NULL) + { + if (flags) + free (buffer); + goto nomem; + } + + chunk->dummy_scn.elf = elf; + chunk->dummy_scn.flags = flags; + chunk->data.s = &chunk->dummy_scn; + chunk->data.d.d_buf = buffer; + chunk->data.d.d_size = size; + chunk->data.d.d_type = type; + chunk->data.d.d_align = align; + chunk->data.d.d_version = __libelf_version; + + rwlock_unlock (elf->lock); + rwlock_wrlock (elf->lock); + + chunk->next = elf->state.elf.rawchunks; + elf->state.elf.rawchunks = chunk; + result = &chunk->data.d; + + out: + rwlock_unlock (elf->lock); + return result; +} |