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arm64: Add support for GOT and PCREL32 relocations.

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This commit is contained in:
Vladimir Serbinenko 2017-02-01 21:46:19 +01:00
parent 377c121170
commit 34fe0b5901
9 changed files with 226 additions and 54 deletions
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96
grub-core/kern/arm64/dl.c
View file

@ -25,14 +25,9 @@
#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.
@ -53,42 +48,6 @@ grub_arch_dl_check_header (void *ehdr)
#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
*/
@ -97,6 +56,7 @@ 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);
@ -145,7 +105,7 @@ grub_arch_dl_relocate_symbols (grub_dl_t mod, void *ehdr,
if (!grub_arm_64_check_xxxx26_offset (offset))
{
struct trampoline *tp = mod->trampptr;
struct grub_arm64_trampoline *tp = mod->trampptr;
mod->trampptr = tp + 1;
tp->ldr = LDR;
tp->br = BR;
@ -160,6 +120,56 @@ grub_arch_dl_relocate_symbols (grub_dl_t mod, void *ehdr,
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);

39
grub-core/kern/arm64/dl_helper.c
View file

@ -93,3 +93,42 @@ grub_arm64_set_abs_lo12_ldst64 (grub_uint32_t *place, grub_int64_t target)
*place &= insmask;
*place |= grub_cpu_to_le32 (target << 7) & ~insmask;
}
#pragma GCC diagnostic ignored "-Wcast-align"
grub_err_t
grub_arm64_dl_get_tramp_got_size (const void *ehdr, grub_size_t *tramp,
grub_size_t *got)
{
const Elf64_Ehdr *e = ehdr;
const Elf64_Shdr *s;
unsigned i;
*tramp = 0;
*got = 0;
for (i = 0, s = (Elf64_Shdr *) ((char *) e + grub_le_to_cpu64 (e->e_shoff));
i < grub_le_to_cpu16 (e->e_shnum);
i++, s = (Elf64_Shdr *) ((char *) s + grub_le_to_cpu16 (e->e_shentsize)))
if (s->sh_type == grub_cpu_to_le32_compile_time (SHT_REL)
|| s->sh_type == grub_cpu_to_le32_compile_time (SHT_RELA))
{
const Elf64_Rela *rel, *max;
for (rel = (Elf64_Rela *) ((char *) e + grub_le_to_cpu64 (s->sh_offset)),
max = (const Elf64_Rela *) ((grub_addr_t) rel + grub_le_to_cpu64 (s->sh_size));
rel < max; rel = (const Elf64_Rela *) ((grub_addr_t) rel + grub_le_to_cpu64 (s->sh_entsize)))
switch (ELF64_R_TYPE (rel->r_info))
{
case R_AARCH64_CALL26:
case R_AARCH64_JUMP26:
*tramp += sizeof (struct grub_arm64_trampoline);
break;
case R_AARCH64_ADR_GOT_PAGE:
*got += 8;
break;
}
}
return GRUB_ERR_NONE;
}