x86_64: clobber flags in clear_page()
PATCH 1/1 x86_64: clobber flags in clear_page()
All clear_page() implementations use XOR which resets flags.
Judging by allyesconfig disassembly no code is affected.
Signed-off-by Alexey Dobriyan <[email protected]>
---
arch/x86/include/asm/page_64.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
arch/x86/include/asm/page_64.h +1 -1
@@ -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);
Quoted 13 lines · Alexey Dobriyan
All
clear_page()implementations use XOR which resets flags.Judging by allyesconfig disassembly no code is affected.
Signed-off-by Alexey Dobriyan <[email protected]>---
arch/x86/include/asm/page_64.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
arch/x86/include/asm/page_64.h static inline void clear_page(void *page) · line 53
Quoted 8 lines
arch/x86/include/asm/page_64.h +1
-1@@ -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);
Reviewed-by Borislav Petkov <[email protected]>
Signature · 5 lines
Regards/Gruss,
Boris.
SUSE Linux GmbH, GF: Felix Imendörffer, Jane Smithard, Graham Norton, HRB 21284 (AG Nürnberg)
-- tip-bot for Alexey Dobriyan
merge bot[tip:x86/asm] x86/asm: Clobber flags in clear_page()
In reply to Alexey Dobriyanx86/asm: Clobber flags in clear_page()
Commit-ID: 1acdbf7ea8a80706561013346d281d282a3c00f9 Gitweb: https://git.kernel.org/tip/1acdbf7ea8a80706561013346d281d282a3c00f9 Author: Alexey Dobriyan <[email protected]> AuthorDate: Sat, 13 Jan 2018 21:50:48 +0300 Committer: Ingo Molnar <[email protected]> CommitDate: Tue, 13 Feb 2018 17:36:49 +0100
x86/asm: Clobber flags in clear_page()
All clear_page() implementations use XOR which resets flags.
Judging by allyesconfig disassembly no code is affected.
Signed-off-by Alexey Dobriyan <[email protected]>
Reviewed-by Borislav Petkov <[email protected]>
Cc Linus Torvalds <[email protected]>
Cc Peter Zijlstra <[email protected]>
Cc Thomas Gleixner <[email protected]>
Signed-off-by Ingo Molnar <[email protected]>
--- arch/x86/include/asm/page_64.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
arch/x86/include/asm/page_64.h +1 -1
@@ -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);