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X86-64: Allow copy relocs for building PIE

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This patch allows copy relocs for non-GOT pc-relative relocation in PIE.

bfd/

	* elf64-x86-64.c (elf_x86_64_create_dynamic_sections): Always
	allow copy relocs for building executables.
	(elf_x86_64_check_relocs): Allow copy relocs for non-GOT
	pc-relative relocation in shared object.
	(elf_x86_64_adjust_dynamic_symbol): Allocate copy relocs for
	PIE.
	(elf_x86_64_relocate_section): Don't copy a pc-relative
	relocation into the output file if the symbol needs copy reloc.

ld/testsuite/

	* ld-x86-64/copyreloc-lib.c: New file.
	* ld-x86-64/copyreloc-main.c: Likewise.
	* ld-x86-64/copyreloc-main.out: Likewise.
	* ld-x86-64/copyreloc-main1.rd: Likewise.
	* ld-x86-64/copyreloc-main2.rd: Likewise.

	* ld-x86-64/x86-64.exp: Run copyreloc tests.
This commit is contained in:
H.J. Lu 2014-12-02 15:14:28 -08:00
parent 5da3ffc99d
commit 9a926d55ab
9 changed files with 103 additions and 11 deletions
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11
bfd/ChangeLog
View file

@ -1,3 +1,14 @@
2014-12-02 H.J. Lu <hongjiu.lu@intel.com>
* elf64-x86-64.c (elf_x86_64_create_dynamic_sections): Always
allow copy relocs for building executables.
(elf_x86_64_check_relocs): Allow copy relocs for non-GOT
pc-relative relocation in shared object.
(elf_x86_64_adjust_dynamic_symbol): Allocate copy relocs for
PIE.
(elf_x86_64_relocate_section): Don't copy a pc-relative
relocation into the output file if the symbol needs copy reloc.
2014-12-02 Andrew Bennett <andrew.bennett@imgtec.com>
* elfxx-mips.c (mips_elf_calculate_relocation): Only check for

46
bfd/elf64-x86-64.c
View file

@ -1060,13 +1060,29 @@ elf_x86_64_create_dynamic_sections (bfd *dynobj,
return FALSE;
htab->sdynbss = bfd_get_linker_section (dynobj, ".dynbss");
if (!info->shared)
htab->srelbss = bfd_get_linker_section (dynobj, ".rela.bss");
if (!htab->sdynbss
|| (!info->shared && !htab->srelbss))
if (!htab->sdynbss)
abort ();
if (info->executable)
{
/* Always allow copy relocs for building executables. */
asection *s;
s = bfd_get_linker_section (dynobj, ".rela.bss");
if (s == NULL)
{
const struct elf_backend_data *bed = get_elf_backend_data (dynobj);
s = bfd_make_section_anyway_with_flags (dynobj,
".rela.bss",
(bed->dynamic_sec_flags
| SEC_READONLY));
if (s == NULL
|| ! bfd_set_section_alignment (dynobj, s,
bed->s->log_file_align))
return FALSE;
}
htab->srelbss = s;
}
if (!info->no_ld_generated_unwind_info
&& htab->plt_eh_frame == NULL
&& htab->elf.splt != NULL)
@ -1939,7 +1955,8 @@ do_size:
storing information in the relocs_copied field of the hash
table entry. A similar situation occurs when creating
shared libraries and symbol visibility changes render the
symbol local.
symbol local. We allow copy relocs for non-GOT pc-relative
relocation.
If on the other hand, we are creating an executable, we
may need to keep relocations for symbols satisfied by a
@ -1949,6 +1966,7 @@ do_size:
&& (sec->flags & SEC_ALLOC) != 0
&& (! IS_X86_64_PCREL_TYPE (r_type)
|| (h != NULL
&& !h->non_got_ref
&& (! SYMBOLIC_BIND (info, h)
|| h->root.type == bfd_link_hash_defweak
|| !h->def_regular))))
@ -2369,7 +2387,7 @@ elf_x86_64_adjust_dynamic_symbol (struct bfd_link_info *info,
only references to the symbol are via the global offset table.
For such cases we need not do anything here; the relocations will
be handled correctly by relocate_section. */
if (info->shared)
if (!info->executable)
return TRUE;
/* If there are no references to this symbol that do not use the
@ -2384,7 +2402,7 @@ elf_x86_64_adjust_dynamic_symbol (struct bfd_link_info *info,
return TRUE;
}
if (ELIMINATE_COPY_RELOCS)
if (ELIMINATE_COPY_RELOCS && !info->shared)
{
eh = (struct elf_x86_64_link_hash_entry *) h;
for (p = eh->dyn_relocs; p != NULL; p = p->next)
@ -4035,10 +4053,11 @@ elf_x86_64_relocate_section (bfd *output_bfd,
defined locally or for a branch. */
fail = !h->def_regular && !branch;
}
else
else if (!h->needs_copy)
{
/* Symbol isn't referenced locally. We only allow
branch to symbol with non-default visibility. */
/* Symbol doesn't need copy reloc and isn't referenced
locally. We only allow branch to symbol with
non-default visibility. */
fail = (!branch
|| ELF_ST_VISIBILITY (h->other) == STV_DEFAULT);
}
@ -4092,7 +4111,12 @@ direct:
if ((input_section->flags & SEC_ALLOC) == 0)
break;
/* Don't copy a pc-relative relocation into the output file
if the symbol needs copy reloc. */
if ((info->shared
&& !(h != NULL
&& h->needs_copy
&& IS_X86_64_PCREL_TYPE (r_type))
&& (h == NULL
|| ELF_ST_VISIBILITY (h->other) == STV_DEFAULT
|| h->root.type != bfd_link_hash_undefweak)

10
ld/testsuite/ChangeLog
View file

@ -1,3 +1,13 @@
2014-12-02 H.J. Lu <hongjiu.lu@intel.com>
* ld-x86-64/copyreloc-lib.c: New file.
* ld-x86-64/copyreloc-main.c: Likewise.
* ld-x86-64/copyreloc-main.out: Likewise.
* ld-x86-64/copyreloc-main1.rd: Likewise.
* ld-x86-64/copyreloc-main2.rd: Likewise.
* ld-x86-64/x86-64.exp: Run copyreloc tests.
2014-12-02 Andrew Bennett <andrew.bennett@imgtec.com>
* ld-mips-elf/mips-elf.exp: Add undefined weak overflow

1
ld/testsuite/ld-x86-64/copyreloc-lib.c Normal file
View file

@ -0,0 +1 @@
int a_glob = 2;

7
ld/testsuite/ld-x86-64/copyreloc-main.c Normal file
View file

@ -0,0 +1,7 @@
extern int a_glob;
int
main (void)
{
return a_glob != 2;
}

0
ld/testsuite/ld-x86-64/copyreloc-main.out Normal file
View file

3
ld/testsuite/ld-x86-64/copyreloc-main1.rd Normal file
View file

@ -0,0 +1,3 @@
#...
[0-9a-f ]+R_X86_64_COPY+[0-9a-f ]+ +a_glob \+ 0
#...

4
ld/testsuite/ld-x86-64/copyreloc-main2.rd Normal file
View file

@ -0,0 +1,4 @@
#failif
#...
[0-9a-f ]+R_X86_64_NONE.*
#...

32
ld/testsuite/ld-x86-64/x86-64.exp
View file

@ -392,6 +392,30 @@ if { [isnative] && [which $CC] != 0 } {
{{readelf {-Wr} plt-main.rd}} \
"plt-main" \
] \
[list \
"Build copyreloc-lib.so" \
"-shared" \
"-fPIC" \
{ copyreloc-lib.c } \
{} \
"copyreloc-lib.so" \
] \
[list \
"Build copyreloc-main with PIE without -fPIE (1)" \
"tmpdir/copyreloc-lib.so -pie" \
"" \
{ copyreloc-main.c } \
{{readelf {-Wr} copyreloc-main1.rd}} \
"copyreloc-main" \
] \
[list \
"Build copyreloc-main with PIE without -fPIE (2)" \
"tmpdir/copyreloc-lib.so -pie" \
"" \
{ copyreloc-main.c } \
{{readelf {-Wr} copyreloc-main2.rd}} \
"copyreloc-main" \
] \
]
run_ld_link_exec_tests [] [list \
@ -414,6 +438,14 @@ if { [isnative] && [which $CC] != 0 } {
"plt-main.out" \
"-fPIC" \
] \
[list \
"Run copyreloc-main with PIE without -fPIE" \
"tmpdir/copyreloc-lib.so -pie" \
"" \
{ copyreloc-main.c } \
"copyreloc-main" \
"copyreloc-main.out" \
] \
]
if { [istarget "x86_64-*-linux*"] \