[PATCH 1/5] x86/asm/entry/64: move retint_kernel code block closer to its user

[Denys Vlasenko]

"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@xxxxxxxxxx>
CC: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
CC: Steven Rostedt <rostedt@xxxxxxxxxxx>
CC: Ingo Molnar <mingo@xxxxxxxxxx>
CC: Borislav Petkov <bp@xxxxxxxxx>
CC: "H. Peter Anvin" <hpa@xxxxxxxxx>
CC: Andy Lutomirski <luto@xxxxxxxxxxxxxx>
CC: Oleg Nesterov <oleg@xxxxxxxxxx>
CC: Frederic Weisbecker <fweisbec@xxxxxxxxx>
CC: Alexei Starovoitov <ast@xxxxxxxxxxxx>
CC: Will Drewry <wad@xxxxxxxxxxxx>
CC: Kees Cook <keescook@xxxxxxxxxxxx>
CC: x86@xxxxxxxxxx
CC: linux-kernel@xxxxxxxxxxxxxxx
---
 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)
 
-- 
1.8.1.4

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/