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=-6.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 12B23C43381 for ; Mon, 1 Apr 2019 17:30:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D6C8020830 for ; Mon, 1 Apr 2019 17:30:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1554139824; bh=BRM0vHzAXwu6TbIYlpvLys6KhjT+03YGEl0QGcq5ogk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=WCG3xlFypKc1hUdlgr+Pr+Wl8ghVmfLmFr9ddYtzmr9qTT827vDWnytbSRzigzatE 2awDNQFOg6dFPsBcqnLbR3Pp771zdMQgd1x6kpoP5EkxTL4VCcBojG0HDgBVJnMUi8 Mdn19dFy3wT8d6cGub1OI+Gi/4kn1+Imk+CbTCIA= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1733081AbfDARaX (ORCPT ); Mon, 1 Apr 2019 13:30:23 -0400 Received: from mail.kernel.org ([198.145.29.99]:37254 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1733069AbfDARaU (ORCPT ); Mon, 1 Apr 2019 13:30:20 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 082862146E; Mon, 1 Apr 2019 17:30:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1554139819; bh=BRM0vHzAXwu6TbIYlpvLys6KhjT+03YGEl0QGcq5ogk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=OKw219nEIo4rEy7M+fk4uIozRIsSqZah50MUhDlGYVKL/O1mEVz22dS1xGDbuOPDj aPUuLSAo4FFt1n95XcEQb0Jx0DgsaxqqllDISGhBi1LPy4vpuyJoFOf23vB50jO7sp J4bt5jtbN1Vy9yWr6DzXtCCtbyj2j6wQAvxczG38= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Konstantin Khlebnikov , Vasily Averin , Vlastimil Babka , Andrew Morton , Linus Torvalds , Arnd Bergmann Subject: [PATCH 4.4 023/131] mm/rmap: replace BUG_ON(anon_vma->degree) with VM_WARN_ON Date: Mon, 1 Apr 2019 19:01:33 +0200 Message-Id: <20190401170053.954755814@linuxfoundation.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190401170051.645954551@linuxfoundation.org> References: <20190401170051.645954551@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Konstantin Khlebnikov commit e4c5800a3991f0c6a766983535dfc10d51802cf6 upstream. This check effectively catches anon vma hierarchy inconsistence and some vma corruptions. It was effective for catching corner cases in anon vma reusing logic. For now this code seems stable so check could be hidden under CONFIG_DEBUG_VM and replaced with WARN because it's not so fatal. Signed-off-by: Konstantin Khlebnikov Suggested-by: Vasily Averin Acked-by: Vlastimil Babka Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Arnd Bergmann Signed-off-by: Greg Kroah-Hartman --- mm/rmap.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/mm/rmap.c +++ b/mm/rmap.c @@ -408,7 +408,7 @@ void unlink_anon_vmas(struct vm_area_str list_for_each_entry_safe(avc, next, &vma->anon_vma_chain, same_vma) { struct anon_vma *anon_vma = avc->anon_vma; - BUG_ON(anon_vma->degree); + VM_WARN_ON(anon_vma->degree); put_anon_vma(anon_vma); list_del(&avc->same_vma);