From: Borislav Petkov <bp@suse.de>
To: Alexey Dobriyan <adobriyan@gmail.com>
Cc: tglx@linutronix.de, mingo@redhat.com, hpa@zytor.com,
x86@kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] x86_64: clobber flags in clear_page()
Date: Sat, 10 Feb 2018 22:19:46 +0100 [thread overview]
Message-ID: <20180210211945.GA21424@pd.tnic> (raw)
In-Reply-To: <20180113185048.GA23111@avx2>
On Sat, Jan 13, 2018 at 09:50:48PM +0300, Alexey Dobriyan wrote:
> 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);
Reviewed-by: Borislav Petkov <bp@suse.de>
--
Regards/Gruss,
Boris.
SUSE Linux GmbH, GF: Felix Imendörffer, Jane Smithard, Graham Norton, HRB 21284 (AG Nürnberg)
--
next prev parent reply other threads:[~2018-02-10 21:20 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-01-13 18:50 [PATCH] x86_64: clobber flags in clear_page() Alexey Dobriyan
2018-02-10 21:19 ` Borislav Petkov [this message]
2018-02-13 16:59 ` [tip:x86/asm] x86/asm: Clobber " tip-bot for Alexey Dobriyan
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