diff options
Diffstat (limited to 'grub-core/kern/elf.c')
| -rw-r--r-- | grub-core/kern/elf.c | 212 |
1 files changed, 212 insertions, 0 deletions
diff --git a/grub-core/kern/elf.c b/grub-core/kern/elf.c new file mode 100644 index 0000000..9d7149b --- /dev/null +++ b/grub-core/kern/elf.c @@ -0,0 +1,212 @@ +/* elf.c - load ELF files */ +/* + * GRUB -- GRand Unified Bootloader + * Copyright (C) 2003,2004,2005,2006,2007,2008,2009 Free Software Foundation, Inc. + * + * GRUB 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, either version 3 of the License, or + * (at your option) any later version. + * + * GRUB 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 GRUB. If not, see <http://www.gnu.org/licenses/>. + */ + +#include <grub/err.h> +#include <grub/elf.h> +#include <grub/elfload.h> +#include <grub/file.h> +#include <grub/misc.h> +#include <grub/mm.h> +#include <grub/dl.h> +#include <grub/i18n.h> + +GRUB_MOD_LICENSE ("GPLv3+"); + +#pragma GCC diagnostic ignored "-Wcast-align" + +#if defined(__powerpc__) && defined(GRUB_MACHINE_IEEE1275) +#define GRUB_ELF_ENABLE_BI_ENDIAN 1 +#else +#define GRUB_ELF_ENABLE_BI_ENDIAN 0 +#endif + +#if defined(GRUB_CPU_WORDS_BIGENDIAN) +#define GRUB_ELF_NATIVE_ENDIANNESS ELFDATA2MSB +#define GRUB_ELF_OPPOSITE_ENDIANNESS ELFDATA2LSB +#else +#define GRUB_ELF_NATIVE_ENDIANNESS ELFDATA2LSB +#define GRUB_ELF_OPPOSITE_ENDIANNESS ELFDATA2MSB +#endif + +static int grub_elf32_check_endianess_and_bswap_ehdr (grub_elf_t elf); +static int grub_elf64_check_endianess_and_bswap_ehdr (grub_elf_t elf); + +/* Check if EHDR is a valid ELF header. */ +static grub_err_t +grub_elf_check_header (grub_elf_t elf) +{ + Elf32_Ehdr *e = &elf->ehdr.ehdr32; + + if (e->e_ident[EI_MAG0] != ELFMAG0 + || e->e_ident[EI_MAG1] != ELFMAG1 + || e->e_ident[EI_MAG2] != ELFMAG2 + || e->e_ident[EI_MAG3] != ELFMAG3 + || e->e_ident[EI_VERSION] != EV_CURRENT) + return grub_error (GRUB_ERR_BAD_OS, N_("invalid arch-independent ELF magic")); + + if (grub_elf_is_elf32 (elf)) + { + if (!grub_elf32_check_endianess_and_bswap_ehdr (elf)) { + return grub_error (GRUB_ERR_BAD_OS, "invalid ELF endianness magic"); + } + } + else if (grub_elf_is_elf64 (elf)) + { + if (!grub_elf64_check_endianess_and_bswap_ehdr (elf)) { + return grub_error (GRUB_ERR_BAD_OS, "invalid ELF endianness magic"); + } + } + else + return grub_error (GRUB_ERR_BAD_OS, "unknown ELF class"); + + if (e->e_version != EV_CURRENT) + return grub_error (GRUB_ERR_BAD_OS, N_("invalid arch-independent ELF magic")); + + return GRUB_ERR_NONE; +} + +grub_err_t +grub_elf_close (grub_elf_t elf) +{ + grub_file_t file = elf->file; + + grub_free (elf->phdrs); + grub_free (elf->filename); + grub_free (elf); + + if (file) + grub_file_close (file); + + return grub_errno; +} + +grub_elf_t +grub_elf_file (grub_file_t file, const char *filename) +{ + grub_elf_t elf; + + elf = grub_zalloc (sizeof (*elf)); + if (! elf) + return 0; + + elf->file = file; + + if (grub_file_seek (elf->file, 0) == (grub_off_t) -1) + goto fail; + + if (grub_file_read (elf->file, &elf->ehdr, sizeof (elf->ehdr)) + != sizeof (elf->ehdr)) + { + if (!grub_errno) + grub_error (GRUB_ERR_FILE_READ_ERROR, N_("premature end of file %s"), + filename); + goto fail; + } + + if (grub_elf_check_header (elf)) + goto fail; + + elf->filename = grub_strdup (filename); + if (!elf->filename) + goto fail; + + return elf; + +fail: + grub_free (elf->filename); + grub_free (elf->phdrs); + grub_free (elf); + return 0; +} + +grub_elf_t +grub_elf_open (const char *name, enum grub_file_type type) +{ + grub_file_t file; + grub_elf_t elf; + + file = grub_file_open (name, type); + if (! file) + return 0; + + elf = grub_elf_file (file, name); + if (! elf) + grub_file_close (file); + + return elf; +} + + +#define grub_swap_bytes_halfXX grub_swap_bytes16 +#define grub_swap_bytes_wordXX grub_swap_bytes32 + +/* 32-bit */ +#define ehdrXX ehdr32 +#define ELFCLASSXX ELFCLASS32 +#define ElfXX_Addr Elf32_Addr +#define grub_elfXX_size grub_elf32_size +#define grub_elfXX_load grub_elf32_load +#define FOR_ELFXX_PHDRS FOR_ELF32_PHDRS +#define grub_elf_is_elfXX grub_elf_is_elf32 +#define grub_elfXX_load_phdrs grub_elf32_load_phdrs +#define ElfXX_Phdr Elf32_Phdr +#define ElfXX_Ehdr Elf32_Ehdr +#define grub_uintXX_t grub_uint32_t +#define grub_swap_bytes_addrXX grub_swap_bytes32 +#define grub_swap_bytes_offXX grub_swap_bytes32 +#define grub_swap_bytes_XwordXX grub_swap_bytes32 +#define grub_elfXX_check_endianess_and_bswap_ehdr grub_elf32_check_endianess_and_bswap_ehdr + +#include "elfXX.c" + +#undef ehdrXX +#undef ELFCLASSXX +#undef ElfXX_Addr +#undef grub_elfXX_size +#undef grub_elfXX_load +#undef FOR_ELFXX_PHDRS +#undef grub_elf_is_elfXX +#undef grub_elfXX_load_phdrs +#undef ElfXX_Phdr +#undef ElfXX_Ehdr +#undef grub_uintXX_t +#undef grub_swap_bytes_addrXX +#undef grub_swap_bytes_offXX +#undef grub_swap_bytes_XwordXX +#undef grub_elfXX_check_endianess_and_bswap_ehdr + + +/* 64-bit */ +#define ehdrXX ehdr64 +#define ELFCLASSXX ELFCLASS64 +#define ElfXX_Addr Elf64_Addr +#define grub_elfXX_size grub_elf64_size +#define grub_elfXX_load grub_elf64_load +#define FOR_ELFXX_PHDRS FOR_ELF64_PHDRS +#define grub_elf_is_elfXX grub_elf_is_elf64 +#define grub_elfXX_load_phdrs grub_elf64_load_phdrs +#define ElfXX_Phdr Elf64_Phdr +#define ElfXX_Ehdr Elf64_Ehdr +#define grub_uintXX_t grub_uint64_t +#define grub_swap_bytes_addrXX grub_swap_bytes64 +#define grub_swap_bytes_offXX grub_swap_bytes64 +#define grub_swap_bytes_XwordXX grub_swap_bytes64 +#define grub_elfXX_check_endianess_and_bswap_ehdr grub_elf64_check_endianess_and_bswap_ehdr + +#include "elfXX.c" |