From: Linus Torvalds Date: Sat, 5 Dec 2009 23:32:03 +0000 (-0800) Subject: Merge branch 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git... X-Git-Tag: v2.6.33-rc1~396 X-Git-Url: http://git.cascardo.info/?p=cascardo%2Flinux.git;a=commitdiff_plain;h=ef26b1691d11e17af205a4ff9c91458d931d11db Merge branch 'x86-asm-for-linus' of git://git./linux/kernel/git/tip/linux-2.6-tip * 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: include/linux/compiler-gcc4.h: Fix build bug - gcc-4.0.2 doesn't understand __builtin_object_size x86/alternatives: No need for alternatives-asm.h to re-invent stuff already in asm.h x86/alternatives: Check replacementlen <= instrlen at build time x86, 64-bit: Set data segments to null after switching to 64-bit mode x86: Clean up the loadsegment() macro x86: Optimize loadsegment() x86: Add missing might_fault() checks to copy_{to,from}_user() x86-64: __copy_from_user_inatomic() adjustments x86: Remove unused thread_return label from switch_to() x86, 64-bit: Fix bstep_iret jump x86: Don't use the strict copy checks when branch profiling is in use x86, 64-bit: Move K8 B step iret fixup to fault entry asm x86: Generate cmpxchg build failures x86: Add a Kconfig option to turn the copy_from_user warnings into errors x86: Turn the copy_from_user check into an (optional) compile time warning x86: Use __builtin_memset and __builtin_memcpy for memset/memcpy x86: Use __builtin_object_size() to validate the buffer size for copy_from_user() --- ef26b1691d11e17af205a4ff9c91458d931d11db diff --cc include/linux/compiler-gcc4.h index ab3af40a53c6,e6ef279ca20c..94dea3ffbfa1 --- a/include/linux/compiler-gcc4.h +++ b/include/linux/compiler-gcc4.h @@@ -36,18 -36,12 +36,26 @@@ the kernel context */ #define __cold __attribute__((__cold__)) + +#if __GNUC_MINOR__ >= 5 +/* + * Mark a position in code as unreachable. This can be used to + * suppress control flow warnings after asm blocks that transfer + * control elsewhere. + * + * Early snapshots of gcc 4.5 don't support this and we can't detect + * this in the preprocessor, but we can live with this because they're + * unreleased. Really, we need to have autoconf for the kernel. + */ +#define unreachable() __builtin_unreachable() +#endif + #endif + + #if __GNUC_MINOR__ > 0 + #define __compiletime_object_size(obj) __builtin_object_size(obj, 0) + #endif + #if __GNUC_MINOR__ >= 4 + #define __compiletime_warning(message) __attribute__((warning(message))) + #define __compiletime_error(message) __attribute__((error(message))) + #endif