From 627276cb55f33e2dc56eab5b973937c128b7704c Mon Sep 17 00:00:00 2001 From: Denys Vlasenko Date: Mon, 30 Mar 2015 20:09:31 +0200 Subject: [PATCH] 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 Cc: Alexei Starovoitov Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Frederic Weisbecker Cc: H. Peter Anvin Cc: Kees Cook Cc: Linus Torvalds Cc: Oleg Nesterov Cc: Steven Rostedt Cc: Will Drewry Link: http://lkml.kernel.org/r/1427738975-7391-2-git-send-email-dvlasenk@redhat.com Signed-off-by: Ingo Molnar --- 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 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) -- 2.20.1