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=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 58657C433ED for ; Tue, 11 May 2021 00:12:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0B7DA6143B for ; Tue, 11 May 2021 00:12:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229642AbhEKANL (ORCPT ); Mon, 10 May 2021 20:13:11 -0400 Received: from mail.kernel.org ([198.145.29.99]:35096 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229628AbhEKANL (ORCPT ); Mon, 10 May 2021 20:13:11 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 95D14611BE; Tue, 11 May 2021 00:12:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1620691925; bh=mX3+yMOULmuj5WW8rwg7GndSrvOGulZcS+J+i46ytDc=; h=Date:From:To:Subject:From; b=FBdZIC6iyE5e1rhmGlc+AXwsydfMlSJE/QbR7tJq50VGRaMiUtVhsMXkQIIoJMuLQ j3rYfFC/HGRNSv8TuHlX482gGvh0daVcDxlprZ+gS+oV8xziwG1xsrMh5g6MTKdlZL IFEqYE8oC05f//hqIAe8QLOciOSR7SpViLzk/aks= Date: Mon, 10 May 2021 17:12:04 -0700 From: akpm@linux-foundation.org To: hughd@google.com, linmiaohe@huawei.com, mm-commits@vger.kernel.org Subject: + =?US-ASCII?Q?ksm-revert-use-get=5Fksm=5Fpage=5Fnolock-to-get-ksm-page-in-?= =?US-ASCII?Q?remove=5Frmap=5Fitem=5Ffrom=5Ftree.patch?= added to -mm tree Message-ID: <20210511001204.XE0o7Drwk%akpm@linux-foundation.org> User-Agent: s-nail v14.8.16 MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org The patch titled Subject: ksm: revert "use GET_KSM_PAGE_NOLOCK to get ksm page in remove_rmap_item_from_tree()" has been added to the -mm tree. Its filename is ksm-revert-use-get_ksm_page_nolock-to-get-ksm-page-in-remove_rmap_item_from_tree.patch This patch should soon appear at https://ozlabs.org/~akpm/mmots/broken-out/ksm-revert-use-get_ksm_page_nolock-to-get-ksm-page-in-remove_rmap_item_from_tree.patch and later at https://ozlabs.org/~akpm/mmotm/broken-out/ksm-revert-use-get_ksm_page_nolock-to-get-ksm-page-in-remove_rmap_item_from_tree.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: Hugh Dickins Subject: ksm: revert "use GET_KSM_PAGE_NOLOCK to get ksm page in remove_rmap_item_from_tree()" This reverts commit 3e96b6a2e9ad929a3230a22f4d64a74671a0720b. General Protection Fault in rmap_walk_ksm() under memory pressure: remove_rmap_item_from_tree() needs to take page lock, of course. Link: https://lkml.kernel.org/r/alpine.LSU.2.11.2105092253500.1127@eggly.anvils Signed-off-by: Hugh Dickins Cc: Miaohe Lin Signed-off-by: Andrew Morton --- mm/ksm.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/mm/ksm.c~ksm-revert-use-get_ksm_page_nolock-to-get-ksm-page-in-remove_rmap_item_from_tree +++ a/mm/ksm.c @@ -776,11 +776,12 @@ static void remove_rmap_item_from_tree(s struct page *page; stable_node = rmap_item->head; - page = get_ksm_page(stable_node, GET_KSM_PAGE_NOLOCK); + page = get_ksm_page(stable_node, GET_KSM_PAGE_LOCK); if (!page) goto out; hlist_del(&rmap_item->hlist); + unlock_page(page); put_page(page); if (!hlist_empty(&stable_node->hlist)) _ Patches currently in -mm which might be from hughd@google.com are ksm-revert-use-get_ksm_page_nolock-to-get-ksm-page-in-remove_rmap_item_from_tree.patch