diff options
| author | Andy Lutomirski <luto@kernel.org> | 2017-11-02 00:59:01 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-12-25 14:26:17 +0100 |
| commit | 37bae8ecdb518a676c5e12520f393d0069e57dfe (patch) | |
| tree | f37d7c58485f4d3cbff242cd12a36458e3b776f7 /arch/x86/entry/entry_64.S | |
| parent | 7d4bb32bc6fded10ff2874ae1d6d655b5511829c (diff) | |
x86/entry/64: Simplify reg restore code in the standard IRET paths
commit e872045bfd9c465a8555bab4b8567d56a4d2d3bb upstream.
The old code restored all the registers with movq instead of pop.
In theory, this was done because some CPUs have higher movq
throughput, but any gain there would be tiny and is almost certainly
outweighed by the higher text size.
This saves 96 bytes of text.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bpetkov@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/ad82520a207ccd851b04ba613f4f752b33ac05f7.1509609304.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/x86/entry/entry_64.S')
| -rw-r--r-- | arch/x86/entry/entry_64.S | 12 |
1 files changed, 6 insertions, 6 deletions
diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S index f67ac2647dbf..77a67ed991fc 100644 --- a/arch/x86/entry/entry_64.S +++ b/arch/x86/entry/entry_64.S @@ -619,9 +619,9 @@ GLOBAL(swapgs_restore_regs_and_return_to_usermode) 1: #endif SWAPGS - RESTORE_EXTRA_REGS - RESTORE_C_REGS - REMOVE_PT_GPREGS_FROM_STACK 8 + POP_EXTRA_REGS + POP_C_REGS + addq $8, %rsp /* skip regs->orig_ax */ INTERRUPT_RETURN @@ -651,9 +651,9 @@ GLOBAL(restore_regs_and_return_to_kernel) ud2 1: #endif - RESTORE_EXTRA_REGS - RESTORE_C_REGS - REMOVE_PT_GPREGS_FROM_STACK 8 + POP_EXTRA_REGS + POP_C_REGS + addq $8, %rsp /* skip regs->orig_ax */ INTERRUPT_RETURN ENTRY(native_iret) |