[PATCH] x86_64: clobber flags in clear_page()

From: Alexey Dobriyan
Date: Sat Jan 13 2018 - 13:51:00 EST


All clear_page() implementations use XOR which resets flags.

Judging by allyesconfig disassembly no code is affected.

Signed-off-by: Alexey Dobriyan <adobriyan@xxxxxxxxx>
---

arch/x86/include/asm/page_64.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/x86/include/asm/page_64.h
+++ b/arch/x86/include/asm/page_64.h
@@ -47,7 +47,7 @@ static inline void clear_page(void *page)
clear_page_erms, X86_FEATURE_ERMS,
"=D" (page),
"0" (page)
- : "memory", "rax", "rcx");
+ : "cc", "memory", "rax", "rcx");
}

void copy_page(void *to, void *from);