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>

1 files changed, 13 insertions, 12 deletions

diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S
index dbfc8875d735..34d60c34fca8 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)