Commit-ID: 4fbb39108f972437c44e5ffa781b56635d496826 Gitweb: https://git.kernel.org/tip/4fbb39108f972437c44e5ffa781b56635d496826 Author: Andy Lutomirski <l...@kernel.org> AuthorDate: Thu, 2 Nov 2017 00:59:03 -0700 Committer: Ingo Molnar <mi...@kernel.org> CommitDate: Thu, 2 Nov 2017 11:04:39 +0100
x86/entry/64: Use pop instead of movq in syscall_return_via_sysret Saves 64 bytes. Signed-off-by: Andy Lutomirski <l...@kernel.org> Reviewed-by: Borislav Petkov <b...@suse.de> Cc: Borislav Petkov <bpet...@suse.de> Cc: Brian Gerst <brge...@gmail.com> Cc: Dave Hansen <dave.han...@intel.com> Cc: Linus Torvalds <torva...@linux-foundation.org> Cc: Peter Zijlstra <pet...@infradead.org> Cc: Thomas Gleixner <t...@linutronix.de> Link: http://lkml.kernel.org/r/6609b7f74ab31c36604ad746e019ea8495aec76c.1509609304.git.l...@kernel.org Signed-off-by: Ingo Molnar <mi...@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 15539644..4f9b446 100644 --- a/arch/x86/entry/entry_64.S +++ b/arch/x86/entry/entry_64.S @@ -315,10 +315,18 @@ 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)