From: Alexey Dobriyan <adobriyan@gmail.com>
To: tglx@linutronix.de, mingo@redhat.com, hpa@zytor.com
Cc: x86@kernel.org, linux-kernel@vger.kernel.org, bp@suse.de
Subject: [PATCH] x86_64: clobber flags in clear_page()
Date: Sat, 13 Jan 2018 21:50:48 +0300 [thread overview]
Message-ID: <20180113185048.GA23111@avx2> (raw)
All clear_page() implementations use XOR which resets flags.
Judging by allyesconfig disassembly no code is affected.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
---
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);
next reply other threads:[~2018-01-13 18:50 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-01-13 18:50 Alexey Dobriyan [this message]
2018-02-10 21:19 ` [PATCH] x86_64: clobber flags in clear_page() Borislav Petkov
2018-02-13 16:59 ` [tip:x86/asm] x86/asm: Clobber " tip-bot for Alexey Dobriyan
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