| From foo@baz Thu Feb 8 03:30:27 CET 2018 |
| From: Andy Lutomirski <luto@kernel.org> |
| Date: Sun, 28 Jan 2018 10:38:49 -0800 |
| Subject: x86/entry/64: Push extra regs right away |
| |
| From: Andy Lutomirski <luto@kernel.org> |
| |
| (cherry picked from 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@kernel.org> |
| Signed-off-by: Thomas Gleixner <tglx@linutronix.de> |
| Acked-by: Ingo Molnar <mingo@kernel.org> |
| Cc: Borislav Petkov <bp@alien8.de> |
| Cc: Linus Torvalds <torvalds@linux-foundation.org> |
| Cc: Kernel Hardening <kernel-hardening@lists.openwall.com> |
| Link: https://lkml.kernel.org/r/462dff8d4d64dfbfc851fbf3130641809d980ecd.1517164461.git.luto@kernel.org |
| Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| --- |
| arch/x86/entry/entry_64.S | 8 ++++++-- |
| 1 file changed, 6 insertions(+), 2 deletions(-) |
| |
| --- a/arch/x86/entry/entry_64.S |
| +++ b/arch/x86/entry/entry_64.S |
| @@ -177,10 +177,14 @@ GLOBAL(entry_SYSCALL_64_after_swapgs) |
| 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 */ |
| + 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 */ |
| |
| /* IRQs are off. */ |
| - SAVE_EXTRA_REGS |
| movq %rsp, %rdi |
| call do_syscall_64 /* returns with IRQs disabled */ |
| |
