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Date: Tue, 7 Apr 2015 17:26:34 +0200
From: Borislav Petkov <bp@alien8.de>
To: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Steven Rostedt <rostedt@goodmis.org>, "H. Peter Anvin" <hpa@zytor.com>,
        Andy Lutomirski <luto@amacapital.net>, Oleg Nesterov <oleg@redhat.com>,
        Frederic Weisbecker <fweisbec@gmail.com>,
        Alexei Starovoitov <ast@plumgrid.com>, Will Drewry <wad@chromium.org>,
        Kees Cook <keescook@chromium.org>, x86@kernel.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH] x86/asm/entry/64: move opportunistic sysret code to
 syscall code path
Message-ID: <20150407152634.GE14095@pd.tnic>
References: <1427993219-7291-1-git-send-email-dvlasenk@redhat.com>
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On Thu, Apr 02, 2015 at 06:46:59PM +0200, Denys Vlasenko wrote:
> This change does two things:
> 
> Copy-pastes "retint_swapgs:" code into syscall handling code,
> the copy is under "syscall_return:" label. The code is unchanged
> apart from some label renames.
> 
> Removes "opportunistic sysret" code from "retint_swapgs:" code block,
> since now it won't be reached by syscall return. This in fact removes
> most of the code in question.
> 
>    text	   data	    bss	    dec	    hex	filename
>   12530	      0	      0	  12530	   30f2	entry_64.o.before
>   12562	      0	      0	  12562	   3112	entry_64.o
> 
> Run-tested.
> 
> Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
> CC: Linus Torvalds <torvalds@linux-foundation.org>
> CC: Steven Rostedt <rostedt@goodmis.org>
> CC: Ingo Molnar <mingo@kernel.org>
> CC: Borislav Petkov <bp@alien8.de>
> CC: "H. Peter Anvin" <hpa@zytor.com>
> CC: Andy Lutomirski <luto@amacapital.net>
> CC: Oleg Nesterov <oleg@redhat.com>
> CC: Frederic Weisbecker <fweisbec@gmail.com>
> CC: Alexei Starovoitov <ast@plumgrid.com>
> CC: Will Drewry <wad@chromium.org>
> CC: Kees Cook <keescook@chromium.org>
> CC: x86@kernel.org
> CC: linux-kernel@vger.kernel.org
> ---
>  arch/x86/kernel/entry_64.S | 158 ++++++++++++++++++++++++---------------------
>  1 file changed, 86 insertions(+), 72 deletions(-)

Acked-and-tested-by: Borislav Petkov <bp@suse.de>

-- 
Regards/Gruss,
    Boris.

ECO tip #101: Trim your mails when you reply.
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