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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7ABE8C2BB41 for ; Wed, 17 Aug 2022 06:21:30 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id C6BEA6B0073; Wed, 17 Aug 2022 02:21:29 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id C1B836B0074; Wed, 17 Aug 2022 02:21:29 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id B09E48D0001; Wed, 17 Aug 2022 02:21:29 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0017.hostedemail.com [216.40.44.17]) by kanga.kvack.org (Postfix) with ESMTP id A5DE96B0073 for ; Wed, 17 Aug 2022 02:21:29 -0400 (EDT) Received: from smtpin12.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay04.hostedemail.com (Postfix) with ESMTP id 7810B1A0F71 for ; Wed, 17 Aug 2022 06:21:29 +0000 (UTC) X-FDA: 79808087898.12.7A88643 Received: from out30-130.freemail.mail.aliyun.com (out30-130.freemail.mail.aliyun.com [115.124.30.130]) by imf15.hostedemail.com (Postfix) with ESMTP id B4771A01DF for ; Wed, 17 Aug 2022 06:21:26 +0000 (UTC) X-Alimail-AntiSpam:AC=PASS;BC=-1|-1;BR=01201311R151e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=ay29a033018045170;MF=baolin.wang@linux.alibaba.com;NM=1;PH=DS;RN=6;SR=0;TI=SMTPD_---0VMUBGX4_1660717281; Received: from localhost(mailfrom:baolin.wang@linux.alibaba.com fp:SMTPD_---0VMUBGX4_1660717281) by smtp.aliyun-inc.com; Wed, 17 Aug 2022 14:21:22 +0800 From: Baolin Wang To: sj@kernel.org, akpm@linux-foundation.org Cc: baolin.wang@linux.alibaba.com, damon@lists.linux.dev, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: [PATCH] mm/damon: Validate if the pmd entry is present before accessing Date: Wed, 17 Aug 2022 14:21:12 +0800 Message-Id: <2838b6737bc259cf575ff11fd1c4b7fdb340fa73.1660717122.git.baolin.wang@linux.alibaba.com> X-Mailer: git-send-email 1.8.3.1 ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1660717288; a=rsa-sha256; cv=none; b=LRzLCz/cvk/Iz2K9EF/PngbbSyZ4pSppGSII6+fj+3s5MR0fLF7hy/sUbRf92nyotdjZak dJXyLCs3bpVnTdem65e5unyRKCeVHt1dfBmCEMtzX+Gvs5LndmXqE25K107PsAc74qm1co xGdehOaUObY+KHb8vPiffQvfETaZ7bU= ARC-Authentication-Results: i=1; imf15.hostedemail.com; dkim=none; dmarc=pass (policy=none) header.from=alibaba.com; spf=pass (imf15.hostedemail.com: domain of baolin.wang@linux.alibaba.com designates 115.124.30.130 as permitted sender) smtp.mailfrom=baolin.wang@linux.alibaba.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1660717288; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:content-type: content-transfer-encoding:in-reply-to:references; bh=TgyE7dM01AeSLRQ4eNBvbibwIgCmhrhgs16AOfLJTJY=; b=7WVpHUzOb3lvHl5gZTY8P8dZ+wkw/vpz/b+pANJnv8A1+cgWgnWkLTe8SniGWRFcf0neai vRCel/JJn0wGqciXVTf2BUSk+OUjffUxMsllz4Xknv4hWM8LX6/ulW2rty5Cju8K5DNxED TKgaYbpCYSVh/jaQqzgu51ob1q1+7r4= X-Rspamd-Server: rspam07 X-Rspamd-Queue-Id: B4771A01DF X-Rspam-User: Authentication-Results: imf15.hostedemail.com; dkim=none; dmarc=pass (policy=none) header.from=alibaba.com; spf=pass (imf15.hostedemail.com: domain of baolin.wang@linux.alibaba.com designates 115.124.30.130 as permitted sender) smtp.mailfrom=baolin.wang@linux.alibaba.com X-Stat-Signature: 65xeh5bpaor3exd4pk6zrbaz8m3os9xe X-HE-Tag: 1660717286-769051 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: The pmd_huge() is used to validate if the pmd entry is mapped by a huge page, also including the case of non-present (migration or hwpoisoned) pmd entry on arm64 or x86 architectures. Thus we should validate if it is present before making the pmd entry old or getting young state, otherwise we can not get the correct corresponding page. Signed-off-by: Baolin Wang --- mm/damon/vaddr.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/mm/damon/vaddr.c b/mm/damon/vaddr.c index 3c7b9d6..1d16c6c 100644 --- a/mm/damon/vaddr.c +++ b/mm/damon/vaddr.c @@ -304,6 +304,11 @@ static int damon_mkold_pmd_entry(pmd_t *pmd, unsigned long addr, if (pmd_huge(*pmd)) { ptl = pmd_lock(walk->mm, pmd); + if (!pmd_present(*pmd)) { + spin_unlock(ptl); + return 0; + } + if (pmd_huge(*pmd)) { damon_pmdp_mkold(pmd, walk->mm, addr); spin_unlock(ptl); @@ -431,6 +436,11 @@ static int damon_young_pmd_entry(pmd_t *pmd, unsigned long addr, #ifdef CONFIG_TRANSPARENT_HUGEPAGE if (pmd_huge(*pmd)) { ptl = pmd_lock(walk->mm, pmd); + if (!pmd_present(*pmd)) { + spin_unlock(ptl); + return 0; + } + if (!pmd_huge(*pmd)) { spin_unlock(ptl); goto regular_page; -- 1.8.3.1