| Date | Fri, 27 Oct 2017 22:11:05 +0200 | From | Borislav Petkov <> | Subject | Re: [PATCH 06/18] x86/asm/64: Use pop instead of movq in syscall_return_via_sysret |
| |
On Thu, Oct 26, 2017 at 01:26:38AM -0700, Andy Lutomirski wrote: > Saves 64 bytes. > > Signed-off-by: Andy Lutomirski <luto@kernel.org> > --- > arch/x86/entry/entry_64.S | 14 +++++++++++--- > 1 file changed, 11 insertions(+), 3 deletions(-) > > diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S > index d6404a613df4..9dafafa3e0ec 100644 > --- a/arch/x86/entry/entry_64.S > +++ b/arch/x86/entry/entry_64.S > @@ -313,10 +313,18 @@ return_from_SYSCALL_64: > */ > syscall_return_via_sysret: > /* rcx and r11 are already restored (see code above) */ > - RESTORE_EXTRA_REGS > - RESTORE_C_REGS_EXCEPT_RCX_R11 > - movq RSP(%rsp), %rsp > UNWIND_HINT_EMPTY > + POP_EXTRA_REGS > + popq %rsi /* skip r11 */ > + popq %r10 > + popq %r9 > + popq %r8 > + popq %rax > + popq %rsi /* skip rcx */ > + popq %rdx > + popq %rsi > + popq %rdi > + movq RSP-ORIG_RAX(%rsp), %rsp > USERGS_SYSRET64 > END(entry_SYSCALL_64) > > --
Reviewed-by: Borislav Petkov <bp@suse.de>
-- Regards/Gruss, Boris.
SUSE Linux GmbH, GF: Felix Imendörffer, Jane Smithard, Graham Norton, HRB 21284 (AG Nürnberg) --
|