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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E3384ECAAD3 for ; Sun, 11 Sep 2022 23:23:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229583AbiIKXXO (ORCPT ); Sun, 11 Sep 2022 19:23:14 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38060 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229575AbiIKXXG (ORCPT ); Sun, 11 Sep 2022 19:23:06 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2312F24F2D for ; Sun, 11 Sep 2022 16:23:05 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id B7B97B80BD1 for ; Sun, 11 Sep 2022 23:23:04 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 52503C433B5; Sun, 11 Sep 2022 23:23:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1662938583; bh=VHArKHscHSE/WT7YULNPTHyi9ugHlHSIG8SmfO4cOiI=; h=Date:To:From:Subject:From; b=MMsgT9qkggh8+OXFB8+U0lq2l51wdoE1i3pt14ubcF3sPSn03qDJURKH5plDh+9zb D/eEUebvA38YXsJdjjXmPxrUtytGLXZVI1cMD7PFlMykEw9zkQD3h7I9CD0ONS3Vtd L4iOSQTbEyMiwZhbA3J7bwmkpFuEoRBW8i8RjiN4= Date: Sun, 11 Sep 2022 16:23:02 -0700 To: mm-commits@vger.kernel.org, willy@infradead.org, viro@zeniv.linux.org.uk, ruansy.fnst@fujitsu.com, riteshh@linux.ibm.com, rgoldwyn@suse.de, naoya.horiguchi@nec.com, linmiaohe@huawei.com, jane.chu@oracle.com, hch@lst.de, djwong@kernel.org, david@fromorbit.com, dan.j.williams@intel.com, akpm@linux-foundation.org From: Andrew Morton Subject: [merged mm-hotfixes-stable] mm-memory-failure-fix-detection-of-memory_failure-handlers.patch removed from -mm tree Message-Id: <20220911232303.52503C433B5@smtp.kernel.org> Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org The quilt patch titled Subject: mm/memory-failure: fix detection of memory_failure() handlers has been removed from the -mm tree. Its filename was mm-memory-failure-fix-detection-of-memory_failure-handlers.patch This patch was dropped because it was merged into the mm-hotfixes-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: Dan Williams Subject: mm/memory-failure: fix detection of memory_failure() handlers Date: Fri, 26 Aug 2022 10:18:07 -0700 Some pagemap types, like MEMORY_DEVICE_GENERIC (device-dax) do not even have pagemap ops which results in crash signatures like this: BUG: kernel NULL pointer dereference, address: 0000000000000010 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 8000000205073067 P4D 8000000205073067 PUD 2062b3067 PMD 0 Oops: 0000 [#1] PREEMPT SMP PTI CPU: 22 PID: 4535 Comm: device-dax Tainted: G OE N 6.0.0-rc2+ #59 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015 RIP: 0010:memory_failure+0x667/0xba0 [..] Call Trace: ? _printk+0x58/0x73 do_madvise.part.0.cold+0xaf/0xc5 Check for ops before checking if the ops have a memory_failure() handler. Link: https://lkml.kernel.org/r/166153428781.2758201.1990616683438224741.stgit@dwillia2-xfh.jf.intel.com Fixes: 33a8f7f2b3a3 ("pagemap,pmem: introduce ->memory_failure()") Signed-off-by: Dan Williams Acked-by: Naoya Horiguchi Reviewed-by: Miaohe Lin Reviewed-by: Christoph Hellwig Cc: Shiyang Ruan Cc: Darrick J. Wong Cc: Al Viro Cc: Dave Chinner Cc: Goldwyn Rodrigues Cc: Jane Chu Cc: Matthew Wilcox Cc: Ritesh Harjani Signed-off-by: Andrew Morton --- include/linux/memremap.h | 5 +++++ mm/memory-failure.c | 2 +- 2 files changed, 6 insertions(+), 1 deletion(-) --- a/include/linux/memremap.h~mm-memory-failure-fix-detection-of-memory_failure-handlers +++ a/include/linux/memremap.h @@ -139,6 +139,11 @@ struct dev_pagemap { }; }; +static inline bool pgmap_has_memory_failure(struct dev_pagemap *pgmap) +{ + return pgmap->ops && pgmap->ops->memory_failure; +} + static inline struct vmem_altmap *pgmap_altmap(struct dev_pagemap *pgmap) { if (pgmap->flags & PGMAP_ALTMAP_VALID) --- a/mm/memory-failure.c~mm-memory-failure-fix-detection-of-memory_failure-handlers +++ a/mm/memory-failure.c @@ -1928,7 +1928,7 @@ static int memory_failure_dev_pagemap(un * Call driver's implementation to handle the memory failure, otherwise * fall back to generic handler. */ - if (pgmap->ops->memory_failure) { + if (pgmap_has_memory_failure(pgmap)) { rc = pgmap->ops->memory_failure(pgmap, pfn, 1, flags); /* * Fall back to generic handler too if operation is not _ Patches currently in -mm which might be from dan.j.williams@intel.com are