From patchwork Thu Sep 7 16:25:29 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Laurent Dufour X-Patchwork-Id: 811086 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [103.22.144.68]) (using TLSv1.2 with cipher ADH-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 3xp5SR49Z3z9sQl for ; Fri, 8 Sep 2017 02:26:47 +1000 (AEST) Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 3xp5SR3KFszDrZX for ; Fri, 8 Sep 2017 02:26:47 +1000 (AEST) X-Original-To: linuxppc-dev@lists.ozlabs.org Delivered-To: linuxppc-dev@lists.ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=free.fr (client-ip=212.27.42.3; helo=smtp3-g21.free.fr; envelope-from=laurent.du4@free.fr; receiver=) Received: from smtp3-g21.free.fr (smtp3-g21.free.fr [212.27.42.3]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3xp5RJ12D8zDrWN for ; Fri, 8 Sep 2017 02:25:48 +1000 (AEST) Received: from nimbus.lab.toulouse-stg.fr.ibm.com (unknown [78.220.147.143]) (Authenticated sender: laurent.du4) by smtp3-g21.free.fr (Postfix) with ESMTPSA id 79BA313F866; Thu, 7 Sep 2017 18:25:29 +0200 (CEST) From: Laurent Dufour To: benh@kernel.crashing.org, mpe@ellerman.id.au, linuxppc-dev@lists.ozlabs.org Subject: [PATCH] powerpc/mm: Fix missing mmap_sem release Date: Thu, 7 Sep 2017 18:25:29 +0200 Message-Id: <1504801529-15113-1-git-send-email-laurent.du4@free.fr> X-Mailer: git-send-email 2.7.4 X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-kernel@vger.kernel.org Errors-To: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org Sender: "Linuxppc-dev" The commit b5c8f0fd595d ("powerpc/mm: Rework mm_fault_error()") reviewed the way the error path is managed in __do_page_fault() but it was a bit too agressive when handling a case by returning without releasing the mmap_sem. By the way, replacing current->mm->mmap_sem by mm->mmap_sem as mm is set to current->mm. Fixes: b5c8f0fd595d ("powerpc/mm: Rework mm_fault_error()") Cc: Benjamin Herrenschmidt Signed-off-by: Laurent Dufour --- arch/powerpc/mm/fault.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c index 4797d08581ce..f799ccf37d27 100644 --- a/arch/powerpc/mm/fault.c +++ b/arch/powerpc/mm/fault.c @@ -521,10 +521,11 @@ static int __do_page_fault(struct pt_regs *regs, unsigned long address, * User mode? Just return to handle the fatal exception otherwise * return to bad_page_fault */ + up_read(&mm->mmap_sem); return is_user ? 0 : SIGBUS; } - up_read(¤t->mm->mmap_sem); + up_read(&mm->mmap_sem); if (unlikely(fault & VM_FAULT_ERROR)) return mm_fault_error(regs, address, fault);