[tip:x86/asm] x86/asm/entry/64: Move retint_kernel code block closer to its user

tip-bot for Denys Vlasenko
2015-03-31T12:37:45Z

Commit-ID: 627276cb55f33e2dc56eab5b973937c128b7704c
Gitweb: http://git.kernel.org/tip/627276cb55f33e2dc56eab5b973937c128b7704c
Author: Denys Vlasenko <dvlasenk@redhat.com>
AuthorDate: Mon, 30 Mar 2015 20:09:31 +0200
Committer: Ingo Molnar <mingo@kernel.org>
CommitDate: Tue, 31 Mar 2015 09:31:11 +0200

x86/asm/entry/64: Move retint_kernel code block closer to its user

The "retint_kernel" code block is misplaced. Since its logical
continuation is "retint_restore_args", it is more natural to
place it above that label. This also makes two jumps "short".

This change only moves code block around, without changing
logic.

This enables the next simplification: making
"retint_restore_args" label a local numeric one.

Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Will Drewry <wad@chromium.org>
Link: http://lkml.kernel.org/r/1427738975-7391-2-git-send-email-dvlasenk@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
arch/x86/kernel/entry_64.S | 25 +++++++++++++------------
1 file changed, 13 insertions(+), 12 deletions(-)

diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S
index dbfc8875..34d60c3 100644
--- a/arch/x86/kernel/entry_64.S
+++ b/arch/x86/kernel/entry_64.S
@@ -740,7 +740,19 @@ opportunistic_sysret_failed:
SWAPGS
jmp restore_args

-retint_restore_args: /* return to kernel space */
+/* Returning to kernel space */
+#ifdef CONFIG_PREEMPT
+ /* Interrupts are off */
+ /* Check if we need preemption */
+ENTRY(retint_kernel)
+ cmpl $0,PER_CPU_VAR(__preempt_count)
+ jnz retint_restore_args
+ bt $9,EFLAGS(%rsp) /* interrupts were off? */
+ jnc retint_restore_args
+ call preempt_schedule_irq
+ jmp exit_intr
+#endif
+retint_restore_args:
DISABLE_INTERRUPTS(CLBR_ANY)
/*
* The iretq could re-enable interrupts:
@@ -830,17 +842,6 @@ retint_signal:
GET_THREAD_INFO(%rcx)
jmp retint_with_reschedule

-#ifdef CONFIG_PREEMPT
- /* Returning to kernel space. Check if we need preemption */
- /* rcx: threadinfo. interrupts off. */
-ENTRY(retint_kernel)
- cmpl $0,PER_CPU_VAR(__preempt_count)
- jnz retint_restore_args
- bt $9,EFLAGS(%rsp) /* interrupts off? */
- jnc retint_restore_args
- call preempt_schedule_irq
- jmp exit_intr
-#endif
CFI_ENDPROC
END(common_interrupt)