diff mbox

Replace __attribute__((visibility("protected")))

Message ID CAMe9rOqwbrRKYbdQP-XYYpmeqk=G-7nEm435yyqwuLhWa7ZjZw@mail.gmail.com
State Superseded
Headers

Commit Message

H.J. Lu March 6, 2015, 9:11 p.m. UTC 
  On Fri, Mar 6, 2015 at 12:11 PM, Andreas Schwab <schwab@linux-m68k.org> wrote:
> "H.J. Lu" <hongjiu.lu@intel.com> writes:
>
>> diff --git a/elf/ifuncdep2.c b/elf/ifuncdep2.c
>> index 99d1926..599eba7 100644
>> --- a/elf/ifuncdep2.c
>> +++ b/elf/ifuncdep2.c
>> @@ -2,7 +2,8 @@
>>
>>  #include "ifunc-sel.h"
>>
>> -int global __attribute__ ((visibility ("protected"))) = -1;
>> +int global = -1;
>> +asm (".protected global");
>
> Some architectures use a symbol prefix.
>

Here is the updated patch to use __SYMBOL_PREFIX.  OK
to install?

Thanks.

Comments

Mike Frysinger March 6, 2015, 10:31 p.m. UTC | #1 
On 06 Mar 2015 13:11, H.J. Lu wrote:
> On Fri, Mar 6, 2015 at 12:11 PM, Andreas Schwab wrote:
> > "H.J. Lu" <hongjiu.lu@intel.com> writes:
> >
> >> diff --git a/elf/ifuncdep2.c b/elf/ifuncdep2.c
> >> index 99d1926..599eba7 100644
> >> --- a/elf/ifuncdep2.c
> >> +++ b/elf/ifuncdep2.c
> >> @@ -2,7 +2,8 @@
> >>
> >>  #include "ifunc-sel.h"
> >>
> >> -int global __attribute__ ((visibility ("protected"))) = -1;
> >> +int global = -1;
> >> +asm (".protected global");
> >
> > Some architectures use a symbol prefix.
> 
> Here is the updated patch to use __SYMBOL_PREFIX.  OK
> to install?

a bunch of the elf/ files don't utilize __SYMBOL_PREFIX already.  would be nice 
if we have ASM_SYMBOL_NAME to complement the C_SYMBOL_NAME in libc-symbols.h.  
and maybe a protected_def() macro so you could do:
	protected_def (global);

at any rate, this patch as-is lgtm.
-mike
diff mbox

Patch

From d7648b9bfd8b5dc1857249dc28fddde08a48629e Mon Sep 17 00:00:00 2001
From: "H.J. Lu" <hjl.tools@gmail.com>
Date: Fri, 6 Mar 2015 04:55:56 -0800
Subject: [PATCH 3/3] Replace __attribute__((visibility("protected")))

With copy relocation, address of protected data defined in the shared
library may be external.  Compiler shouldn't asssume protected data will
be local.  But due to

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65248

__attribute__((visibility("protected"))) doesn't work correctly, we need
to use asm (".protected xxx") instead.

	* elf/ifuncdep2.c (global): Replace
	__attribute__((visibility("protected"))) with
	asm (".protected " __SYMBOL_PREFIX "global").
	* elf/ifuncmod1.c (global): Likewise.
	* elf/ifuncmod5.c (global): Likewise.
---
 elf/ifuncdep2.c | 3 ++-
 elf/ifuncmod1.c | 3 ++-
 elf/ifuncmod5.c | 3 ++-
 3 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/elf/ifuncdep2.c b/elf/ifuncdep2.c
index 99d1926..4f3a773 100644
--- a/elf/ifuncdep2.c
+++ b/elf/ifuncdep2.c
@@ -2,7 +2,8 @@ 
 
 #include "ifunc-sel.h"
 
-int global __attribute__ ((visibility ("protected"))) = -1;
+int global = -1;
+asm (".protected " __SYMBOL_PREFIX "global");
 
 static int
 one (void)
diff --git a/elf/ifuncmod1.c b/elf/ifuncmod1.c
index 2b8195c..fc10b35 100644
--- a/elf/ifuncmod1.c
+++ b/elf/ifuncmod1.c
@@ -6,7 +6,8 @@ 
  */
 #include "ifunc-sel.h"
 
-int global __attribute__ ((visibility ("protected"))) = -1;
+int global = -1;
+asm (".protected " __SYMBOL_PREFIX "global");
 
 static int
 one (void)
diff --git a/elf/ifuncmod5.c b/elf/ifuncmod5.c
index 9a08e8c..1d3529f 100644
--- a/elf/ifuncmod5.c
+++ b/elf/ifuncmod5.c
@@ -1,7 +1,8 @@ 
 /* Test STT_GNU_IFUNC symbols without direct function call.  */
 #include "ifunc-sel.h"
 
-int global __attribute__ ((visibility ("protected"))) = -1;
+int global = -1;
+asm (".protected " __SYMBOL_PREFIX "global");
 
 static int
 one (void)
-- 
1.9.3