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Correct Nios II GOT pointer initialization.

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2014-02-02  Sandra Loosemore  <sandra@codesourcery.com>

	bfd/
	* elf32-nios2.c (struct elf32_nios2_link_hash_table): Add
	h_gp_got field.
	(nios2_elf32_relocate_section): Use got_base to adjust
	GOT-pointer-relative relocations relative to _gp_got.
	(create_got_section): Create _gp_got symbol.
	(nios2_elf32_finish_dynamic_symbol): Make _gp_got absolute.
	(nios2_elf32_size_dynamic_sections): Set _gp_got offset.
This commit is contained in:
Sandra Loosemore 2014-02-02 10:57:52 -08:00
parent 13075d049d
commit 82e9153868
2 changed files with 53 additions and 14 deletions
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10
bfd/ChangeLog
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@ -1,3 +1,13 @@
2014-02-02 Sandra Loosemore <sandra@codesourcery.com>
* elf32-nios2.c (struct elf32_nios2_link_hash_table): Add
h_gp_got field.
(nios2_elf32_relocate_section): Use got_base to adjust
GOT-pointer-relative relocations relative to _gp_got.
(create_got_section): Create _gp_got symbol.
(nios2_elf32_finish_dynamic_symbol): Make _gp_got absolute.
(nios2_elf32_size_dynamic_sections): Set _gp_got offset.
2014-01-30 Sandra Loosemore <sandra@codesourcery.com>
* bfd-in2.h: Update from reloc.c.

57
bfd/elf32-nios2.c
View File

@ -892,6 +892,9 @@ struct elf32_nios2_link_hash_table
asection *srelbss;
asection *sbss;
/* GOT pointer symbol _gp_got. */
struct elf_link_hash_entry *h_gp_got;
union {
bfd_signed_vma refcount;
bfd_vma offset;
@ -2671,6 +2674,7 @@ nios2_elf32_relocate_section (bfd *output_bfd,
asection *splt;
asection *sreloc = NULL;
bfd_vma *local_got_offsets;
bfd_vma got_base;
symtab_hdr = &elf_tdata (input_bfd)->symtab_hdr;
sym_hashes = elf_sym_hashes (input_bfd);
@ -2681,6 +2685,11 @@ nios2_elf32_relocate_section (bfd *output_bfd,
splt = htab->root.splt;
local_got_offsets = elf_local_got_offsets (input_bfd);
if (elf32_nios2_hash_table (info)->h_gp_got == NULL)
got_base = 0;
else
got_base = elf32_nios2_hash_table (info)->h_gp_got->root.u.def.value;
for (rel = relocs; rel < relend; rel++)
{
reloc_howto_type *howto;
@ -3026,10 +3035,11 @@ nios2_elf32_relocate_section (bfd *output_bfd,
if (use_plt && info->shared)
{
off = ((h->plt.offset - 24) / 12 + 3) * 4;
relocation = htab->root.sgotplt->output_offset + off;
relocation = (htab->root.sgotplt->output_offset + off
- got_base);
}
else
relocation = sgot->output_offset + off;
relocation = sgot->output_offset + off - got_base;
/* This relocation does not use the addend. */
rel->r_addend = 0;
@ -3042,8 +3052,7 @@ nios2_elf32_relocate_section (bfd *output_bfd,
case R_NIOS2_GOTOFF_LO:
case R_NIOS2_GOTOFF_HA:
case R_NIOS2_GOTOFF:
/* Relocation is relative to the start of the
global offset table. */
/* Relocation is relative to the global offset table pointer. */
BFD_ASSERT (sgot != NULL);
if (sgot == NULL)
@ -3052,12 +3061,10 @@ nios2_elf32_relocate_section (bfd *output_bfd,
break;
}
/* Note that sgot->output_offset is not involved in this
calculation. We always want the start of .got. If we
define _GLOBAL_OFFSET_TABLE in a different way, as is
permitted by the ABI, we might have to change this
calculation. */
relocation -= sgot->output_section->vma;
/* Adjust the relocation to be relative to the GOT pointer. */
relocation -= (sgot->output_section->vma
+ sgot->output_offset - got_base);
switch (howto->type)
{
case R_NIOS2_GOTOFF_LO:
@ -3127,7 +3134,7 @@ nios2_elf32_relocate_section (bfd *output_bfd,
htab->tls_ldm_got.offset |= 1;
}
relocation = (htab->root.sgot->output_offset + off);
relocation = htab->root.sgot->output_offset + off - got_base;
r = _bfd_final_link_relocate (howto, input_bfd, input_section,
contents, rel->r_offset,
@ -3284,7 +3291,7 @@ nios2_elf32_relocate_section (bfd *output_bfd,
if ((tls_type & GOT_TLS_GD) && r_type != R_NIOS2_TLS_GD16)
off += 8;
relocation = (htab->root.sgot->output_offset + off);
relocation = htab->root.sgot->output_offset + off - got_base;
r = _bfd_final_link_relocate (howto, input_bfd, input_section,
contents, rel->r_offset,
@ -3489,6 +3496,7 @@ static bfd_boolean
create_got_section (bfd *dynobj, struct bfd_link_info *info)
{
struct elf32_nios2_link_hash_table *htab;
struct elf_link_hash_entry *h;
htab = elf32_nios2_hash_table (info);
@ -3500,6 +3508,16 @@ create_got_section (bfd *dynobj, struct bfd_link_info *info)
if (!bfd_set_section_alignment (dynobj, htab->root.sgotplt, 4))
return FALSE;
/* The Nios II ABI specifies that GOT-relative relocations are relative
to the linker-created symbol _gp_got, rather than using
_GLOBAL_OFFSET_TABLE_ directly. In particular, the latter always
points to the base of the GOT while _gp_got may include a bias. */
h = _bfd_elf_define_linkage_sym (dynobj, info, htab->root.sgotplt,
"_gp_got");
elf32_nios2_hash_table (info)->h_gp_got = h;
if (h == NULL)
return FALSE;
return TRUE;
}
@ -4178,9 +4196,10 @@ nios2_elf32_finish_dynamic_symbol (bfd *output_bfd,
bfd_elf32_swap_reloca_out (output_bfd, &rela, loc);
}
/* Mark _DYNAMIC and _GLOBAL_OFFSET_TABLE_ as absolute. */
/* Mark _DYNAMIC, _GLOBAL_OFFSET_TABLE_, and _gp_got as absolute. */
if (strcmp (h->root.root.string, "_DYNAMIC") == 0
|| h == elf_hash_table (info)->hgot)
|| h == elf_hash_table (info)->hgot
|| h == elf32_nios2_hash_table (info)->h_gp_got)
sym->st_shndx = SHN_ABS;
return TRUE;
@ -4846,6 +4865,16 @@ nios2_elf32_size_dynamic_sections (bfd *output_bfd ATTRIBUTE_UNUSED,
sym dynamic relocs. */
elf_link_hash_traverse (& htab->root, allocate_dynrelocs, info);
if (elf_hash_table (info)->dynamic_sections_created)
{
/* If the .got section is more than 0x8000 bytes, we add
0x8000 to the value of _gp_got, so that 16-bit relocations
have a greater chance of working. */
if (htab->root.sgot->size >= 0x8000
&& elf32_nios2_hash_table (info)->h_gp_got->root.u.def.value == 0)
elf32_nios2_hash_table (info)->h_gp_got->root.u.def.value = 0x8000;
}
/* The check_relocs and adjust_dynamic_symbol entry points have
determined the sizes of the various dynamic sections. Allocate
memory for them. */