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x86-64: Force symbol dynamic if it isn't undefined weak 

Force symbol dynamic if it isn't undefined weak.  Generate relative
relocation for GOT reference against non-dynamic symbol in PIC to
avoid unnecessary dynamic symbols.

bfd/

	* elf64-x86-64.c (elf_x86_64_link_hash_entry): Add
	no_finish_dynamic_symbol.
	(elf_x86_64_link_hash_newfunc): Set no_finish_dynamic_symbol to
	0.
	(elf_x86_64_allocate_dynrelocs): If a symbol isn't undefined
	weak symbol, don't make it dynamic.
	(elf_x86_64_relocate_section): If a symbol isn't dynamic in PIC,
	set no_finish_dynamic_symbol and generate R_X86_64_RELATIVE
	relocation for GOT reference.
	(elf_x86_64_finish_dynamic_symbol): Abort if
	no_finish_dynamic_symbol isn't 0.

ld/

	* testsuite/ld-x86-64/no-plt.exp: Also check no-plt-1e.nd.
	* testsuite/ld-x86-64/no-plt-1e.nd: New file.
binutils-2_29-branch
H.J. Lu 9 years ago
parent
0dc9a308a1
commit
9e9821ddd8
5 changed files with 72 additions and 22 deletions
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  1. 14
      bfd/ChangeLog
  2. 66
      bfd/elf64-x86-64.c
  3. 5
      ld/ChangeLog
  4. 7
      ld/testsuite/ld-x86-64/no-plt-1e.nd
  5. 2
      ld/testsuite/ld-x86-64/no-plt.exp

14
bfd/ChangeLog
View File

@ -1,3 +1,17 @@
2017-04-24 H.J. Lu <hongjiu.lu@intel.com>
* elf64-x86-64.c (elf_x86_64_link_hash_entry): Add
no_finish_dynamic_symbol.
(elf_x86_64_link_hash_newfunc): Set no_finish_dynamic_symbol to
0.
(elf_x86_64_allocate_dynrelocs): If a symbol isn't undefined
weak symbol, don't make it dynamic.
(elf_x86_64_relocate_section): If a symbol isn't dynamic in PIC,
set no_finish_dynamic_symbol and generate R_X86_64_RELATIVE
relocation for GOT reference.
(elf_x86_64_finish_dynamic_symbol): Abort if
no_finish_dynamic_symbol isn't 0.
2017-04-24 H.J. Lu <hongjiu.lu@intel.com>
PR ld/21402

66
bfd/elf64-x86-64.c
View File

@ -867,6 +867,9 @@ struct elf_x86_64_link_hash_entry
/* TRUE if symbol has non-GOT/non-PLT relocations in text sections. */
unsigned int has_non_got_reloc : 1;
/* Don't call finish_dynamic_symbol on this symbol. */
unsigned int no_finish_dynamic_symbol : 1;
/* 0: symbol isn't __tls_get_addr.
1: symbol is __tls_get_addr.
2: symbol is unknown. */
@ -1022,6 +1025,7 @@ elf_x86_64_link_hash_newfunc (struct bfd_hash_entry *entry,
eh->has_bnd_reloc = 0;
eh->has_got_reloc = 0;
eh->has_non_got_reloc = 0;
eh->no_finish_dynamic_symbol = 0;
eh->tls_get_addr = 2;
eh->func_pointer_refcount = 0;
eh->plt_bnd.offset = (bfd_vma) -1;
@ -3218,7 +3222,8 @@ elf_x86_64_allocate_dynrelocs (struct elf_link_hash_entry *h, void * inf)
Undefined weak syms won't yet be marked as dynamic. */
if (h->dynindx == -1
&& !h->forced_local
&& !resolved_to_zero)
&& !resolved_to_zero
&& h->root.type == bfd_link_hash_undefweak)
{
if (! bfd_elf_link_record_dynamic_symbol (info, h))
return FALSE;
@ -3338,7 +3343,8 @@ elf_x86_64_allocate_dynrelocs (struct elf_link_hash_entry *h, void * inf)
Undefined weak syms won't yet be marked as dynamic. */
if (h->dynindx == -1
&& !h->forced_local
&& !resolved_to_zero)
&& !resolved_to_zero
&& h->root.type == bfd_link_hash_undefweak)
{
if (! bfd_elf_link_record_dynamic_symbol (info, h))
return FALSE;
@ -3475,6 +3481,7 @@ elf_x86_64_allocate_dynrelocs (struct elf_link_hash_entry *h, void * inf)
if (h->dynindx == -1
&& ! h->forced_local
&& ! resolved_to_zero
&& h->root.type == bfd_link_hash_undefweak
&& ! bfd_elf_link_record_dynamic_symbol (info, h))
return FALSE;
@ -4270,6 +4277,7 @@ elf_x86_64_relocate_section (bfd *output_bfd,
asection *base_got, *resolved_plt;
bfd_vma st_size;
bfd_boolean resolved_to_zero;
bfd_boolean relative_reloc;
r_type = ELF32_R_TYPE (rel->r_info);
if (r_type == (int) R_X86_64_GNU_VTINHERIT
@ -4637,6 +4645,7 @@ do_ifunc_pointer:
if (htab->elf.sgot == NULL)
abort ();
relative_reloc = FALSE;
if (h != NULL)
{
bfd_boolean dyn;
@ -4683,6 +4692,17 @@ do_ifunc_pointer:
/* Note that this is harmless for the GOTPLT64 case,
as -1 | 1 still is -1. */
h->got.offset |= 1;
if (h->dynindx == -1
&& !h->forced_local
&& h->root.type != bfd_link_hash_undefweak
&& bfd_link_pic (info))
{
/* If this symbol isn't dynamic in PIC,
generate R_X86_64_RELATIVE here. */
eh->no_finish_dynamic_symbol = 1;
relative_reloc = TRUE;
}
}
}
else
@ -4704,30 +4724,32 @@ do_ifunc_pointer:
{
bfd_put_64 (output_bfd, relocation,
base_got->contents + off);
local_got_offsets[r_symndx] |= 1;
if (bfd_link_pic (info))
{
asection *s;
Elf_Internal_Rela outrel;
/* We need to generate a R_X86_64_RELATIVE reloc
for the dynamic linker. */
s = htab->elf.srelgot;
if (s == NULL)
abort ();
outrel.r_offset = (base_got->output_section->vma
+ base_got->output_offset
+ off);
outrel.r_info = htab->r_info (0, R_X86_64_RELATIVE);
outrel.r_addend = relocation;
elf_append_rela (output_bfd, s, &outrel);
}
local_got_offsets[r_symndx] |= 1;
relative_reloc = TRUE;
}
}
if (relative_reloc)
{
asection *s;
Elf_Internal_Rela outrel;
/* We need to generate a R_X86_64_RELATIVE reloc
for the dynamic linker. */
s = htab->elf.srelgot;
if (s == NULL)
abort ();
outrel.r_offset = (base_got->output_section->vma
+ base_got->output_offset
+ off);
outrel.r_info = htab->r_info (0, R_X86_64_RELATIVE);
outrel.r_addend = relocation;
elf_append_rela (output_bfd, s, &outrel);
}
if (off >= (bfd_vma) -2)
abort ();
@ -5797,6 +5819,8 @@ elf_x86_64_finish_dynamic_symbol (bfd *output_bfd,
: get_elf_x86_64_backend_data (output_bfd));
eh = (struct elf_x86_64_link_hash_entry *) h;
if (eh->no_finish_dynamic_symbol)
abort ();
/* We keep PLT/GOT entries without dynamic PLT/GOT relocations for
resolved undefined weak symbols in executable so that their

5
ld/ChangeLog
View File

@ -1,3 +1,8 @@
2017-04-24 H.J. Lu <hongjiu.lu@intel.com>
* testsuite/ld-x86-64/no-plt.exp: Also check no-plt-1e.nd.
* testsuite/ld-x86-64/no-plt-1e.nd: New file.
2017-04-24 H.J. Lu <hongjiu.lu@intel.com>
* testsuite/ld-i386/pr12570a.d: Skip for nacl targets.

7
ld/testsuite/ld-x86-64/no-plt-1e.nd
View File

@ -0,0 +1,7 @@
#nm: -g -D
#target: x86_64-*-*
#failif
#...
[0-9]+ +T +func
#...

2
ld/testsuite/ld-x86-64/no-plt.exp
View File

@ -111,7 +111,7 @@ run_cc_link_tests [list \
tmpdir/no-plt-func1.o tmpdir/no-plt-extern1.o" \
"" \
{dummy.s} \
{{readelf -Wr no-plt-1e.rd} {objdump -dwrj.text no-plt-1e.dd}} \
{{readelf -Wr no-plt-1e.rd} {nm -gD no-plt-1e.nd} {objdump -dwrj.text no-plt-1e.dd}} \
"no-plt-1e" \
] \
[list \

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