grub/grub-core/kern/x86_64/dl.c
H.J. Lu 1c4dc293df x86-64: Treat R_X86_64_PLT32 as R_X86_64_PC32
Starting from binutils commit bd7ab16b4537788ad53521c45469a1bdae84ad4a:

https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=bd7ab16b4537788ad53521c45469a1bdae84ad4a

x86-64 assembler generates R_X86_64_PLT32, instead of R_X86_64_PC32, for
32-bit PC-relative branches.  Grub2 should treat R_X86_64_PLT32 as
R_X86_64_PC32.

Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
(cherry picked from commit 842c390469)
2019-10-24 16:59:37 +02:00

116 lines
3.3 KiB
C

/* 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:
return grub_error (GRUB_ERR_NOT_IMPLEMENTED_YET,
N_("relocation 0x%x is not implemented yet"),
ELF_R_TYPE (rel->r_info));
}
}
return GRUB_ERR_NONE;
}