From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-19.6 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 03F96C433E6 for ; Wed, 10 Feb 2021 02:38:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B31F364E70 for ; Wed, 10 Feb 2021 02:38:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235507AbhBJCiI (ORCPT ); Tue, 9 Feb 2021 21:38:08 -0500 Received: from mail.kernel.org ([198.145.29.99]:34224 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234717AbhBJCfS (ORCPT ); Tue, 9 Feb 2021 21:35:18 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 38E9064E5A; Wed, 10 Feb 2021 02:33:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1612924432; bh=VpiGszjWRCGHlsfY5CAAKkwNjbQ/B7h8CaWG22qvxBw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=qcCavE9dj5Bb958GMdiptMZ+lvDAzf9w5NIQxCjd3Nm/XANU7LhtxiaWTnOxijH6A Hz7keBK5/xeKQqZEKY87jOj3uICgCtkMppwuVU5XPMH+5j596eZuJllOSLFt/cW59g 6I9WiKKZ6SVgQODiMCf5mCoGCl5CC53/DMVg2zYHpXHrXlxCDN/hv8hQI8bBrbUIEK 7QaLrq+6BCiUqODiaszABS29HtGQE5nEs6pC4iuF19ZwgSJPGXbsOHRzvhAZEaa0J3 nBBNHPBqzfI/NfwUmN9i0Y+eNLxWa0V8ct6ljnatIJ/dDPECIA9vgMEJ9MdYC08OCs ClzrDUisbZ3og== From: Andy Lutomirski To: x86@kernel.org Cc: LKML , Dave Hansen , Alexei Starovoitov , Daniel Borkmann , Yonghong Song , Masami Hiramatsu , Andy Lutomirski , Peter Zijlstra Subject: [PATCH v2 05/14] x86/fault: Document the locking in the fault_signal_pending() path Date: Tue, 9 Feb 2021 18:33:37 -0800 Message-Id: X-Mailer: git-send-email 2.29.2 In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org If fault_signal_pending() returns true, then the core mm has unlocked the mm for us. Add a comment to help future readers of this code. Cc: Dave Hansen Cc: Peter Zijlstra Signed-off-by: Andy Lutomirski --- arch/x86/mm/fault.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c index 3ffed003f281..013910b7b93f 100644 --- a/arch/x86/mm/fault.c +++ b/arch/x86/mm/fault.c @@ -1380,8 +1380,11 @@ void do_user_addr_fault(struct pt_regs *regs, */ fault = handle_mm_fault(vma, address, flags, regs); - /* Quick path to respond to signals */ if (fault_signal_pending(fault, regs)) { + /* + * Quick path to respond to signals. The core mm code + * has unlocked the mm for us if we get here. + */ if (!user_mode(regs)) no_context(regs, error_code, address, SIGBUS, BUS_ADRERR); -- 2.29.2