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/* dl.c - arch-dependent part of loadable module support */
/*
* GRUB -- GRand Unified Bootloader
* Copyright (C) 2013 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/mm.h>
#include <grub/i18n.h>
#include <grub/cpu/reloc.h>
struct trampoline
{
#define LDR 0x58000050
#define BR 0xd61f0200
grub_uint32_t ldr; /* ldr x16, 8 */
grub_uint32_t br; /* br x16 */
grub_uint64_t addr;
};
/*
* Check if EHDR is a valid ELF header.
*/
grub_err_t
grub_arch_dl_check_header (void *ehdr)
{
Elf_Ehdr *e = ehdr;
/* Check the magic numbers. */
if (e->e_ident[EI_CLASS] != ELFCLASS64
|| e->e_ident[EI_DATA] != ELFDATA2LSB || e->e_machine != EM_AARCH64)
return grub_error (GRUB_ERR_BAD_OS,
N_("invalid arch-dependent ELF magic"));
return GRUB_ERR_NONE;
}
#pragma GCC diagnostic ignored "-Wcast-align"
grub_err_t
grub_arch_dl_get_tramp_got_size (const void *ehdr, grub_size_t *tramp,
grub_size_t *got)
{
const Elf_Ehdr *e = ehdr;
const Elf_Shdr *s;
unsigned i;
*tramp = 0;
*got = 0;
for (i = 0, s = (const Elf_Shdr *) ((grub_addr_t) e + e->e_shoff);
i < e->e_shnum;
i++, s = (const Elf_Shdr *) ((grub_addr_t) s + e->e_shentsize))
if (s->sh_type == SHT_REL || s->sh_type == SHT_RELA)
{
const Elf_Rel *rel, *max;
for (rel = (const Elf_Rel *) ((grub_addr_t) e + s->sh_offset),
max = rel + s->sh_size / s->sh_entsize;
rel < max;
rel = (const Elf_Rel *) ((grub_addr_t) rel + s->sh_entsize))
switch (ELF_R_TYPE (rel->r_info))
{
case R_AARCH64_CALL26:
case R_AARCH64_JUMP26:
{
*tramp += sizeof (struct trampoline);
break;
}
}
}
return GRUB_ERR_NONE;
}
/*
* Unified function for both REL and RELA
*/
grub_err_t
grub_arch_dl_relocate_symbols (grub_dl_t mod, void *ehdr,
Elf_Shdr *s, grub_dl_segment_t seg)
{
Elf_Rel *rel, *max;
for (rel = (Elf_Rel *) ((char *) ehdr + s->sh_offset),
max = (Elf_Rel *) ((char *) rel + s->sh_size);
rel < max;
rel = (Elf_Rel *) ((char *) rel + s->sh_entsize))
{
Elf_Sym *sym;
void *place;
grub_uint64_t sym_addr;
if (rel->r_offset >= seg->size)
return grub_error (GRUB_ERR_BAD_MODULE,
"reloc offset is out of the segment");
sym = (Elf_Sym *) ((char *) mod->symtab
+ mod->symsize * ELF_R_SYM (rel->r_info));
sym_addr = sym->st_value;
if (s->sh_type == SHT_RELA)
sym_addr += ((Elf_Rela *) rel)->r_addend;
place = (void *) ((grub_addr_t) seg->addr + rel->r_offset);
switch (ELF_R_TYPE (rel->r_info))
{
case R_AARCH64_ABS64:
{
grub_uint64_t *abs_place = place;
grub_dprintf ("dl", " reloc_abs64 %p => 0x%016llx\n",
place, (unsigned long long) sym_addr);
*abs_place = (grub_uint64_t) sym_addr;
}
break;
case R_AARCH64_ADD_ABS_LO12_NC:
grub_arm64_set_abs_lo12 (place, sym_addr);
break;
case R_AARCH64_LDST64_ABS_LO12_NC:
grub_arm64_set_abs_lo12_ldst64 (place, sym_addr);
break;
case R_AARCH64_CALL26:
case R_AARCH64_JUMP26:
{
grub_int64_t offset = sym_addr - (grub_uint64_t) place;
if (!grub_arm_64_check_xxxx26_offset (offset))
{
struct trampoline *tp = mod->trampptr;
mod->trampptr = tp + 1;
tp->ldr = LDR;
tp->br = BR;
tp->addr = sym_addr;
offset = (grub_uint8_t *) tp - (grub_uint8_t *) place;
}
if (!grub_arm_64_check_xxxx26_offset (offset))
return grub_error (GRUB_ERR_BAD_MODULE,
"trampoline out of range");
grub_arm64_set_xxxx26_offset (place, offset);
}
break;
case R_AARCH64_ADR_PREL_PG_HI21:
{
grub_int64_t offset = (sym_addr & ~0xfffULL) - (((grub_uint64_t) place) & ~0xfffULL);
if (!grub_arm64_check_hi21_signed (offset))
return grub_error (GRUB_ERR_BAD_MODULE,
"HI21 out of range");
grub_arm64_set_hi21 (place, offset);
}
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;
}
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