[PATCH] gcc4: Disable __compiletime_object_size for GCC 4.6+

From: Guenter Roeck
Date: Fri Apr 12 2013 - 22:49:20 EST


__builtin_object_size is known to be broken on gcc 4.6+.
See http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48880 for details.

This causes unnecssary build warnings and errors such as

In function 'copy_from_user', inlined from 'sb16_copy_from_user'
at sound/oss/sb_audio.c:878:22:
arch/x86/include/asm/uaccess_32.h:211:26: error: call to 'copy_from_user_overflow'
declared with attribute error: copy_from_user() buffer size is not provably correct
make[3]: [sound/oss/sb_audio.o] Error 1 (ignored)

Disable it where broken.

Signed-off-by: Guenter Roeck <linux@xxxxxxxxxxxx>
---
include/linux/compiler-gcc4.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/linux/compiler-gcc4.h b/include/linux/compiler-gcc4.h
index 68b162d..842de22 100644
--- a/include/linux/compiler-gcc4.h
+++ b/include/linux/compiler-gcc4.h
@@ -13,7 +13,7 @@
#define __must_check __attribute__((warn_unused_result))
#define __compiler_offsetof(a,b) __builtin_offsetof(a,b)

-#if GCC_VERSION >= 40100
+#if GCC_VERSION >= 40100 && GCC_VERSION < 40600
# define __compiletime_object_size(obj) __builtin_object_size(obj, 0)
#endif

--
1.7.9.7

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