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_RED 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 3CEB6C11F66 for ; Thu, 1 Jul 2021 01:52:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 208E061469 for ; Thu, 1 Jul 2021 01:52:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238418AbhGAByj (ORCPT ); Wed, 30 Jun 2021 21:54:39 -0400 Received: from mail.kernel.org ([198.145.29.99]:44158 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238416AbhGAByj (ORCPT ); Wed, 30 Jun 2021 21:54:39 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 78AE661468; Thu, 1 Jul 2021 01:52:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1625104329; bh=2dZWw63BUDFoIX03mW6b/itp6jdWGNjUtM9R8vs/XTg=; h=Date:From:To:Subject:In-Reply-To:From; b=s+LYQvHSQlqg+3J09xpPnX0w9v/EVNA1+l0Xl+VO/JhOptpQHG3qsptan03fTlhiY 1rKczMnSSBYNwH/LdHOSjdJvm1kpiGLF54vdCMJdqsKueVSJku1U3qVfr6Mcy3vNkE ILOi29TwUYfQjo/zIO2QARrVoJGznmctyJf8WpNM= Date: Wed, 30 Jun 2021 18:52:08 -0700 From: Andrew Morton To: akpm@linux-foundation.org, apopple@nvidia.com, hughd@google.com, jack@suse.cz, juew@google.com, kirill.shutemov@linux.intel.com, linmiaohe@huawei.com, linux-mm@kvack.org, minchan@kernel.org, mm-commits@vger.kernel.org, naoya.horiguchi@nec.com, osalvador@suse.de, peterx@redhat.com, rcampbell@nvidia.com, shakeelb@google.com, shy828301@gmail.com, torvalds@linux-foundation.org, wangyugui@e16-tech.com, willy@infradead.org, ziy@nvidia.com Subject: [patch 093/192] mm: hwpoison_user_mappings() try_to_unmap() with TTU_SYNC Message-ID: <20210701015208.xKgFl8Tfb%akpm@linux-foundation.org> In-Reply-To: <20210630184624.9ca1937310b0dd5ce66b30e7@linux-foundation.org> User-Agent: s-nail v14.8.16 Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org From: Hugh Dickins Subject: mm: hwpoison_user_mappings() try_to_unmap() with TTU_SYNC TTU_SYNC prevents an unlikely race, when try_to_unmap() returns shortly before the page is accounted as unmapped. It is unlikely to coincide with hwpoisoning, but now that we have the flag, hwpoison_user_mappings() would do well to use it. Link: https://lkml.kernel.org/r/329c28ed-95df-9a2c-8893-b444d8a6d340@google.com Signed-off-by: Hugh Dickins Acked-by: Kirill A. Shutemov Acked-by: Naoya Horiguchi Cc: Alistair Popple Cc: Jan Kara Cc: Jue Wang Cc: "Matthew Wilcox (Oracle)" Cc: Miaohe Lin Cc: Minchan Kim Cc: Oscar Salvador Cc: Peter Xu Cc: Ralph Campbell Cc: Shakeel Butt Cc: Wang Yugui Cc: Yang Shi Cc: Zi Yan Signed-off-by: Andrew Morton --- mm/memory-failure.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/mm/memory-failure.c~mm-hwpoison_user_mappings-try_to_unmap-with-ttu_sync +++ a/mm/memory-failure.c @@ -1266,7 +1266,7 @@ static int get_hwpoison_page(struct page static bool hwpoison_user_mappings(struct page *p, unsigned long pfn, int flags, struct page **hpagep) { - enum ttu_flags ttu = TTU_IGNORE_MLOCK; + enum ttu_flags ttu = TTU_IGNORE_MLOCK | TTU_SYNC; struct address_space *mapping; LIST_HEAD(tokill); bool unmap_success; _