diff options
Diffstat (limited to 'grub-core/kern/x86_64/dl.c')
| -rw-r--r-- | grub-core/kern/x86_64/dl.c | 121 |
1 files changed, 121 insertions, 0 deletions
diff --git a/grub-core/kern/x86_64/dl.c b/grub-core/kern/x86_64/dl.c new file mode 100644 index 0000000..e5a8bdc --- /dev/null +++ b/grub-core/kern/x86_64/dl.c @@ -0,0 +1,121 @@ +/* dl-x86_64.c - arch-dependent part of loadable module support */ +/* + * GRUB -- GRand Unified Bootloader + * Copyright (C) 2002,2005,2007,2009 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/dl.h> +#include <grub/elf.h> +#include <grub/misc.h> +#include <grub/err.h> +#include <grub/i18n.h> + +/* Check if EHDR is a valid ELF header. */ +grub_err_t +grub_arch_dl_check_header (void *ehdr) +{ + Elf64_Ehdr *e = ehdr; + + /* Check the magic numbers. */ + if (e->e_ident[EI_CLASS] != ELFCLASS64 + || e->e_ident[EI_DATA] != ELFDATA2LSB + || e->e_machine != EM_X86_64) + return grub_error (GRUB_ERR_BAD_OS, N_("invalid arch-dependent ELF magic")); + + return GRUB_ERR_NONE; +} + +/* Relocate symbols. */ +grub_err_t +grub_arch_dl_relocate_symbols (grub_dl_t mod, void *ehdr, + Elf_Shdr *s, grub_dl_segment_t seg) +{ + Elf64_Rela *rel, *max; + + for (rel = (Elf64_Rela *) ((char *) ehdr + s->sh_offset), + max = (Elf64_Rela *) ((char *) rel + s->sh_size); + rel < max; + rel = (Elf64_Rela *) ((char *) rel + s->sh_entsize)) + { + Elf64_Word *addr32; + Elf64_Xword *addr64; + Elf64_Sym *sym; + + if (seg->size < rel->r_offset) + return grub_error (GRUB_ERR_BAD_MODULE, + "reloc offset is out of the segment"); + + addr32 = (Elf64_Word *) ((char *) seg->addr + rel->r_offset); + addr64 = (Elf64_Xword *) addr32; + sym = (Elf64_Sym *) ((char *) mod->symtab + + mod->symsize * ELF_R_SYM (rel->r_info)); + + switch (ELF_R_TYPE (rel->r_info)) + { + case R_X86_64_64: + *addr64 += rel->r_addend + sym->st_value; + break; + + case R_X86_64_PC32: + case R_X86_64_PLT32: + { + grub_int64_t value; + value = ((grub_int32_t) *addr32) + rel->r_addend + sym->st_value - + (Elf64_Xword) (grub_addr_t) seg->addr - rel->r_offset; + if (value != (grub_int32_t) value) + return grub_error (GRUB_ERR_BAD_MODULE, "relocation out of range"); + *addr32 = value; + } + break; + + case R_X86_64_PC64: + { + *addr64 += rel->r_addend + sym->st_value - + (Elf64_Xword) (grub_addr_t) seg->addr - rel->r_offset; + } + break; + + case R_X86_64_32: + { + grub_uint64_t value = *addr32 + rel->r_addend + sym->st_value; + if (value != (grub_uint32_t) value) + return grub_error (GRUB_ERR_BAD_MODULE, "relocation out of range"); + *addr32 = value; + } + break; + case R_X86_64_32S: + { + grub_int64_t value = ((grub_int32_t) *addr32) + rel->r_addend + sym->st_value; + if (value != (grub_int32_t) value) + return grub_error (GRUB_ERR_BAD_MODULE, "relocation out of range"); + *addr32 = value; + } + break; + + default: + { + char rel_info[17]; /* log16(2^64) = 16, plus NUL. */ + + grub_snprintf (rel_info, sizeof (rel_info) - 1, "%" PRIxGRUB_UINT64_T, + ELF_R_TYPE (rel->r_info)); + return grub_error (GRUB_ERR_NOT_IMPLEMENTED_YET, + N_("relocation 0x%s is not implemented yet"), rel_info); + } + } + } + + return GRUB_ERR_NONE; +} |