diff options
| author | Andy Lutomirski <luto@kernel.org> | 2017-11-02 00:59:04 -0700 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2017-11-02 11:04:40 +0100 |
| commit | a512210643da8082cb44181dba8b18e752bd68f0 (patch) | |
| tree | 098acb63d7d07d2b8e4ca8a473cb9a063aaf5ea5 /arch/x86/entry/entry_64.S | |
| parent | 4fbb39108f972437c44e5ffa781b56635d496826 (diff) | |
x86/entry/64: Merge the fast and slow SYSRET paths
They did almost the same thing. Remove a bunch of pointless
instructions (mostly hidden in macros) and reduce cognitive load by
merging them.
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/1204e20233fcab9130a1ba80b3b1879b5db3fc1f.1509609304.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/entry/entry_64.S')
| -rw-r--r-- | arch/x86/entry/entry_64.S | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S index 4f9b4463b3fc..b5a0ea63d391 100644 --- a/arch/x86/entry/entry_64.S +++ b/arch/x86/entry/entry_64.S @@ -220,10 +220,9 @@ entry_SYSCALL_64_fastpath: TRACE_IRQS_ON /* user mode is traced as IRQs on */ movq RIP(%rsp), %rcx movq EFLAGS(%rsp), %r11 - RESTORE_C_REGS_EXCEPT_RCX_R11 - movq RSP(%rsp), %rsp + addq $6*8, %rsp /* skip extra regs -- they were preserved */ UNWIND_HINT_EMPTY - USERGS_SYSRET64 + jmp .Lpop_c_regs_except_rcx_r11_and_sysret 1: /* @@ -317,6 +316,7 @@ syscall_return_via_sysret: /* rcx and r11 are already restored (see code above) */ UNWIND_HINT_EMPTY POP_EXTRA_REGS +.Lpop_c_regs_except_rcx_r11_and_sysret: popq %rsi /* skip r11 */ popq %r10 popq %r9 |