Re: [PATCH] x86/asm/entry/64: move opportunistic sysret code to syscall code path

[Borislav Petkov]

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@xxxxxxxxxx>
> CC: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
> CC: Steven Rostedt <rostedt@xxxxxxxxxxx>
> CC: Ingo Molnar <mingo@xxxxxxxxxx>
> CC: Borislav Petkov <bp@xxxxxxxxx>
> CC: "H. Peter Anvin" <hpa@xxxxxxxxx>
> CC: Andy Lutomirski <luto@xxxxxxxxxxxxxx>
> CC: Oleg Nesterov <oleg@xxxxxxxxxx>
> CC: Frederic Weisbecker <fweisbec@xxxxxxxxx>
> CC: Alexei Starovoitov <ast@xxxxxxxxxxxx>
> CC: Will Drewry <wad@xxxxxxxxxxxx>
> CC: Kees Cook <keescook@xxxxxxxxxxxx>
> CC: x86@xxxxxxxxxx
> CC: linux-kernel@xxxxxxxxxxxxxxx
> ---
>  arch/x86/kernel/entry_64.S | 158 ++++++++++++++++++++++++---------------------
>  1 file changed, 86 insertions(+), 72 deletions(-)

Acked-and-tested-by: Borislav Petkov <bp@xxxxxxx>

-- 
Regards/Gruss,
    Boris.

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