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PR gold/12980

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* i386.cc (Target_i386::Scan::global): For a GOT reloc, use a
	GLOB_DAT relocation rather than a RELATIVE relocation for a
	protected symbol when creating a shared library.
	* x86_64.cc (Target_x86_64::Scan::global): Likewise.
	* testsuite/protected_1.cc (f2, get_f2_addr): New functions.
	* testsuite/protected_main_1.cc (main): Test that protected
	function has same address.
This commit is contained in:
Ian Lance Taylor 2011-07-12 22:29:09 +00:00
parent a7035dbbd1
commit 07aa62f267
5 changed files with 70 additions and 0 deletions
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11
gold/ChangeLog
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@ -1,3 +1,14 @@
2011-07-12 Ian Lance Taylor <iant@google.com>
PR gold/12980
* i386.cc (Target_i386::Scan::global): For a GOT reloc, use a
GLOB_DAT relocation rather than a RELATIVE relocation for a
protected symbol when creating a shared library.
* x86_64.cc (Target_x86_64::Scan::global): Likewise.
* testsuite/protected_1.cc (f2, get_f2_addr): New functions.
* testsuite/protected_main_1.cc (main): Test that protected
function has same address.
2011-07-11 Ian Lance Taylor <iant@google.com>
PR gold/12979

15
gold/i386.cc
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@ -1985,9 +1985,24 @@ Target_i386::Scan::global(Symbol_table* symtab,
// If this symbol is not fully resolved, we need to add a
// GOT entry with a dynamic relocation.
Reloc_section* rel_dyn = target->rel_dyn_section(layout);
// Use a GLOB_DAT rather than a RELATIVE reloc if:
//
// 1) The symbol may be defined in some other module.
//
// 2) We are building a shared library and this is a
// protected symbol; using GLOB_DAT means that the dynamic
// linker can use the address of the PLT in the main
// executable when appropriate so that function address
// comparisons work.
//
// 3) This is a STT_GNU_IFUNC symbol in position dependent
// code, again so that function address comparisons work.
if (gsym->is_from_dynobj()
|| gsym->is_undefined()
|| gsym->is_preemptible()
|| (gsym->visibility() == elfcpp::STV_PROTECTED
&& parameters->options().shared())
|| (gsym->type() == elfcpp::STT_GNU_IFUNC
&& parameters->options().output_is_position_independent()))
got->add_global_with_rel(gsym, GOT_TYPE_STANDARD,

25
gold/testsuite/protected_1.cc
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@ -31,3 +31,28 @@ f1()
{
return 1;
}
// The function f2 is used to test that the executable can see the
// same function address for a protected function in the executable
// and in the shared library. We can't use the visibility attribute
// here, becaues that may cause gcc to generate a PC relative reloc;
// we need it to get the value from the GOT. I'm not sure this is
// really useful, given that it doesn't work with the visibility
// attribute. This test exists here mainly because the glibc
// testsuite has the same test, and we want to make sure that gold
// passes the glibc testsuite.
extern "C" int f2();
asm(".protected f2");
extern "C" int
f2()
{
return 2;
}
int
(*get_f2_addr())()
{
return f2;
}

4
gold/testsuite/protected_main_1.cc
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@ -28,9 +28,13 @@
extern bool t1();
extern bool t2();
extern "C" int f2();
extern int (*get_f2_addr()) ();
int
main()
{
assert(t1());
assert(t2());
assert(&f2 == get_f2_addr());
}

15
gold/x86_64.cc
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@ -2436,9 +2436,24 @@ Target_x86_64::Scan::global(Symbol_table* symtab,
// If this symbol is not fully resolved, we need to add a
// dynamic relocation for it.
Reloc_section* rela_dyn = target->rela_dyn_section(layout);
// Use a GLOB_DAT rather than a RELATIVE reloc if:
//
// 1) The symbol may be defined in some other module.
//
// 2) We are building a shared library and this is a
// protected symbol; using GLOB_DAT means that the dynamic
// linker can use the address of the PLT in the main
// executable when appropriate so that function address
// comparisons work.
//
// 3) This is a STT_GNU_IFUNC symbol in position dependent
// code, again so that function address comparisons work.
if (gsym->is_from_dynobj()
|| gsym->is_undefined()
|| gsym->is_preemptible()
|| (gsym->visibility() == elfcpp::STV_PROTECTED
&& parameters->options().shared())
|| (gsym->type() == elfcpp::STT_GNU_IFUNC
&& parameters->options().output_is_position_independent()))
got->add_global_with_rela(gsym, GOT_TYPE_STANDARD, rela_dyn,