From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753466AbbC3SK2 (ORCPT ); Mon, 30 Mar 2015 14:10:28 -0400 Received: from mx1.redhat.com ([209.132.183.28]:37068 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753355AbbC3SKX (ORCPT ); Mon, 30 Mar 2015 14:10:23 -0400 From: Denys Vlasenko To: Ingo Molnar Cc: Denys Vlasenko , Linus Torvalds , Steven Rostedt , Borislav Petkov , "H. Peter Anvin" , Andy Lutomirski , Oleg Nesterov , Frederic Weisbecker , Alexei Starovoitov , Will Drewry , Kees Cook , x86@kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 1/5] x86/asm/entry/64: move retint_kernel code block closer to its user Date: Mon, 30 Mar 2015 20:09:31 +0200 Message-Id: <1427738975-7391-2-git-send-email-dvlasenk@redhat.com> In-Reply-To: <1427738975-7391-1-git-send-email-dvlasenk@redhat.com> References: <1427738975-7391-1-git-send-email-dvlasenk@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org "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: Linus Torvalds CC: Steven Rostedt CC: Ingo Molnar CC: Borislav Petkov CC: "H. Peter Anvin" CC: Andy Lutomirski CC: Oleg Nesterov CC: Frederic Weisbecker CC: Alexei Starovoitov CC: Will Drewry CC: Kees Cook CC: x86@kernel.org CC: linux-kernel@vger.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) -- 1.8.1.4