grub/grub-core/kern/arm64/dl.c
2017-02-01 21:46:19 +01:00

193 lines
5.6 KiB
C

/* 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>
#define LDR 0x58000050
#define BR 0xd61f0200
/*
* 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"
/*
* 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;
unsigned unmatched_adr_got_page = 0;
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 grub_arm64_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_PREL32:
{
grub_int64_t value;
Elf64_Word *addr32 = place;
value = ((grub_int32_t) *addr32) + sym_addr -
(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");
grub_dprintf("dl", " reloc_prel32 %p => 0x%016llx\n",
place, (unsigned long long) sym_addr);
*addr32 = value;
}
break;
case R_AARCH64_ADR_GOT_PAGE:
{
grub_uint64_t *gp = mod->gotptr;
Elf_Rela *rel2;
grub_int64_t gpoffset = ((grub_uint64_t) gp & ~0xfffULL) - (((grub_uint64_t) place) & ~0xfffULL);
*gp = (grub_uint64_t) sym_addr;
mod->gotptr = gp + 1;
unmatched_adr_got_page++;
grub_dprintf("dl", " reloc_got %p => 0x%016llx (0x%016llx)\n",
place, (unsigned long long) sym_addr, (unsigned long long) gp);
if (!grub_arm64_check_hi21_signed (gpoffset))
return grub_error (GRUB_ERR_BAD_MODULE,
"HI21 out of range");
grub_arm64_set_hi21(place, gpoffset);
for (rel2 = (Elf_Rela *) ((char *) rel + s->sh_entsize);
rel2 < (Elf_Rela *) max;
rel2 = (Elf_Rela *) ((char *) rel2 + s->sh_entsize))
if (ELF_R_SYM (rel2->r_info)
== ELF_R_SYM (rel->r_info)
&& ((Elf_Rela *) rel)->r_addend == rel2->r_addend
&& ELF_R_TYPE (rel2->r_info) == R_AARCH64_LD64_GOT_LO12_NC)
{
grub_arm64_set_abs_lo12_ldst64 ((void *) ((grub_addr_t) seg->addr + rel2->r_offset),
(grub_uint64_t)gp);
break;
}
if (rel2 >= (Elf_Rela *) max)
return grub_error (GRUB_ERR_BAD_MODULE,
"ADR_GOT_PAGE without matching LD64_GOT_LO12_NC");
}
break;
case R_AARCH64_LD64_GOT_LO12_NC:
if (unmatched_adr_got_page == 0)
return grub_error (GRUB_ERR_BAD_MODULE,
"LD64_GOT_LO12_NC without matching ADR_GOT_PAGE");
unmatched_adr_got_page--;
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;
}