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Date: Sat, 14 Mar 2015 17:00:42 +0100
From: Pavel Machek <pavel@ucw.cz>
To: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Andy Lutomirski <luto@amacapital.net>,
        Linus Torvalds <torvalds@linux-foundation.org>,
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        Kees Cook <keescook@chromium.org>, x86@kernel.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH 2/2 v2] x86: make 32-bit "emergency stack" better
 documented
Message-ID: <20150314160042.GA1338@xo-6d-61-c0.localdomain>
References: <1425912738-559-1-git-send-email-dvlasenk@redhat.com>
 <1425912738-559-2-git-send-email-dvlasenk@redhat.com>
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Hi!

>  arch/x86/kernel/asm-offsets_32.c | 2 +-
>  arch/x86/kernel/cpu/common.c     | 3 ++-
>  3 files changed, 5 insertions(+), 4 deletions(-)
> 
> diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
> index 48a61c1..9e65cf8 100644
> --- a/arch/x86/include/asm/processor.h
> +++ b/arch/x86/include/asm/processor.h
> @@ -276,9 +276,9 @@ struct tss_struct {
>  	unsigned long		io_bitmap[IO_BITMAP_LONGS + 1];
>  
>  	/*
> -	 * .. and then another 0x100 bytes for the emergency kernel stack:
> +	 * and then space for temporary SYSENTER stack:
>  	 */
> -	unsigned long		stack[64];
> +	unsigned long		SYSENTER_stack[64];

Would it make sense to make it unsigned char ...stack[256], like the comment said?

Or is it supposed to be different size on 64bit, and comment was wrong?

									Pavel
-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html