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 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id C1865CD4F26 for ; Fri, 26 Jun 2026 11:18:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Type: Content-Transfer-Encoding:MIME-Version:References:In-Reply-To:Message-ID:Date :Subject:CC:To:From:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=+dgrebeHjs4fpxqiQop24k7ud/2CLXwg2SgO1/ChW0o=; b=HXNI69poiQRlTj4VH9vdkjx+/O AdoXs2DbWzxQh5Suu349YncjPkD7k7syDNoDcBSRbWTxtOGrqIHIBzg5IJn2nwfpTHZ7bBZRofOUJ 0EL/nveWFBv0PkFcsClbzOYEL89Srcmb2Wc+HRe4UznRsDC7S41B/iGeChi4xqVLeZPMrrRVDveLF HGi1CvfgSx/gvJRnhEnVDiyxDk+HH+9HG8YHginx6COvnKWFu3nMSqYhtI+N2DWWZ42H6yej1hIFU KItumu4VhPBbxNQltCjZSgI+GBkO2xgpR/fxKEjf6U6wH2t5m/WPhSvn34U1arlrKM2fKnYAzAKRy ImrDRZaQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wd3ci-0000000B4vT-3RbF; Fri, 26 Jun 2026 10:17:24 +0000 Received: from canpmsgout08.his.huawei.com ([113.46.200.223]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1wd3cc-0000000B4le-0dkf for linux-arm-kernel@lists.infradead.org; Fri, 26 Jun 2026 10:17:24 +0000 dkim-signature: v=1; a=rsa-sha256; d=huawei.com; s=dkim; c=relaxed/relaxed; q=dns/txt; h=From; bh=+dgrebeHjs4fpxqiQop24k7ud/2CLXwg2SgO1/ChW0o=; b=QIR/CpMKuhnyRARQVpkEnuyoAYO8fHYJtBAgGdtOnkbmAI7pjaS10Gym833rMASL2GnrETCAK hi+LXXZNs6iP1czILOvDS4naDBe1fzgC52avPQJ29IsxKqeqCHmQMJPxqMRGS6CB8Afq8EVJwT6 q1VrGUkslPNt3305PFJ8PUc= Received: from mail.maildlp.com (unknown [172.19.163.15]) by canpmsgout08.his.huawei.com (SkyGuard) with ESMTPS id 4gmrw16PzWzmV6M; Fri, 26 Jun 2026 18:08:01 +0800 (CST) Received: from kwepemj100009.china.huawei.com (unknown [7.202.194.3]) by mail.maildlp.com (Postfix) with ESMTPS id A833540539; Fri, 26 Jun 2026 18:17:08 +0800 (CST) Received: from DESKTOP-A37P9LK.huawei.com (10.67.109.17) by kwepemj100009.china.huawei.com (7.202.194.3) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.36; Fri, 26 Jun 2026 18:17:08 +0800 From: Xie Yuanbin To: , CC: , , , , Subject: Re: [PATCH v3 2/2] ARM: mm: protect show_pte() in do_DataAbort() fallback path Date: Fri, 26 Jun 2026 18:16:15 +0800 Message-ID: <20260626101615.60920-1-xieyuanbin1@huawei.com> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260626073048.3595106-3-xiqi2@huawei.com> References: <20260626073048.3595106-3-xiqi2@huawei.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain X-Originating-IP: [10.67.109.17] X-ClientProxiedBy: kwepems500001.china.huawei.com (7.221.188.70) To kwepemj100009.china.huawei.com (7.202.194.3) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260626_031718_696791_66D6A5DC X-CRM114-Status: UNSURE ( 7.09 ) X-CRM114-Notice: Please train this message. X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Fri, 26 Jun 2026 15:30:48 +0800, Qi Xi wrote: > @@ -638,7 +638,10 @@ do_DataAbort(unsigned long addr, unsigned int fsr, struct pt_regs *regs) > pr_alert("8<--- cut here ---\n"); > pr_alert("Unhandled fault: %s (0x%03x) at 0x%08lx\n", > inf->name, fsr, addr); > - show_pte(KERN_ALERT, current->mm, addr); > + if (mmap_read_trylock(current->mm)) { > + show_pte(KERN_ALERT, current->mm, addr); > + mmap_read_unlock(current->mm); > + } For kernel faults, `current->mm` maybe NULL, and `mmap_read_trylock(current->mm)` may cause a panic. Also, interrupts may be disabled here. I suggest that waiting for this patch to be merged first: https://lore.kernel.org/20260625122612.43501-1-xieyuanbin1@huawei.com which make sure that interrupts are enabled here. Then, something like: ```c if (user_mode(regs)) mmap_read_lock(current->mm); show_pte(KERN_ALERT, current->mm, addr); if (user_mode(regs)) mmap_read_unlock(current->mm); ```