diff options
Diffstat (limited to 'arch/x86/include/asm/processor.h')
| -rw-r--r-- | arch/x86/include/asm/processor.h | 14 |
1 files changed, 12 insertions, 2 deletions
diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h index c7768269b1cf..70c6a939031b 100644 --- a/arch/x86/include/asm/processor.h +++ b/arch/x86/include/asm/processor.h @@ -179,7 +179,7 @@ static inline void native_cpuid(unsigned int *eax, unsigned int *ebx, unsigned int *ecx, unsigned int *edx) { /* ecx is often an input as well as an output. */ - asm("cpuid" + asm volatile("cpuid" : "=a" (*eax), "=b" (*ebx), "=c" (*ecx), @@ -403,7 +403,17 @@ extern unsigned long kernel_eflags; extern asmlinkage void ignore_sysret(void); #else /* X86_64 */ #ifdef CONFIG_CC_STACKPROTECTOR -DECLARE_PER_CPU(unsigned long, stack_canary); +/* + * Make sure stack canary segment base is cached-aligned: + * "For Intel Atom processors, avoid non zero segment base address + * that is not aligned to cache line boundary at all cost." + * (Optim Ref Manual Assembly/Compiler Coding Rule 15.) + */ +struct stack_canary { + char __pad[20]; /* canary at %gs:20 */ + unsigned long canary; +}; +DECLARE_PER_CPU(struct stack_canary, stack_canary) ____cacheline_aligned; #endif #endif /* X86_64 */ |