From: Andi Kleen <a...@linux.intel.com> LTO in gcc 4.6/47. has trouble with global register variables. They were used to read the stack pointer. Use a simple inline assembler statement instead.
I verified this generates the same binary (on 64bit) as the original register variable. Signed-off-by: Andi Kleen <a...@linux.intel.com> --- arch/x86/include/asm/thread_info.h | 8 +++++--- 1 files changed, 5 insertions(+), 3 deletions(-) diff --git a/arch/x86/include/asm/thread_info.h b/arch/x86/include/asm/thread_info.h index 89f794f..d9fbfa1 100644 --- a/arch/x86/include/asm/thread_info.h +++ b/arch/x86/include/asm/thread_info.h @@ -167,9 +167,11 @@ struct thread_info { */ #ifndef __ASSEMBLY__ - -/* how to get the current stack pointer from C */ -register unsigned long current_stack_pointer asm("esp") __used; +#define current_stack_pointer ({ \ + unsigned long sp; \ + asm("mov %%esp,%0" : "=r" (sp)); \ + sp; \ +}) /* how to get the thread information struct from C */ static inline struct thread_info *current_thread_info(void) -- 1.7.7.6 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/