[PATCH 4.14 34/64] x86/entry/64: Push extra regs right away
From: Greg Kroah-Hartman
Date: Mon Feb 05 2018 - 13:25:39 EST
4.14-stable review patch. If anyone has any objections, please let me know.
------------------
From: Andy Lutomirski luto@xxxxxxxxxx
commit d1f7732009e0549eedf8ea1db948dc37be77fd46
With the fast path removed there is no point in splitting the push of the
normal and the extra register set. Just push the extra regs right away.
[ tglx: Split out from 'x86/entry/64: Remove the SYSCALL64 fast path' ]
Signed-off-by: Andy Lutomirski <luto@xxxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Acked-by: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Kernel Hardening <kernel-hardening@xxxxxxxxxxxxxxxxxx>
Link: https://lkml.kernel.org/r/462dff8d4d64dfbfc851fbf3130641809d980ecd.1517164461.git.luto@xxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/x86/entry/entry_64.S | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)
--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -232,13 +232,17 @@ GLOBAL(entry_SYSCALL_64_after_hwframe)
pushq %r9 /* pt_regs->r9 */
pushq %r10 /* pt_regs->r10 */
pushq %r11 /* pt_regs->r11 */
- sub $(6*8), %rsp /* pt_regs->bp, bx, r12-15 not saved */
- UNWIND_HINT_REGS extra=0
+ pushq %rbx /* pt_regs->rbx */
+ pushq %rbp /* pt_regs->rbp */
+ pushq %r12 /* pt_regs->r12 */
+ pushq %r13 /* pt_regs->r13 */
+ pushq %r14 /* pt_regs->r14 */
+ pushq %r15 /* pt_regs->r15 */
+ UNWIND_HINT_REGS
TRACE_IRQS_OFF
/* IRQs are off. */
- SAVE_EXTRA_REGS
movq %rsp, %rdi
call do_syscall_64 /* returns with IRQs disabled */