From patchwork Wed May 12 03:10:57 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kefeng Wang X-Patchwork-Id: 12252599 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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 C1784C43460 for ; Wed, 12 May 2021 03:01:15 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 1BA1961942 for ; Wed, 12 May 2021 03:01:15 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1BA1961942 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=huawei.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id A39996B0036; Tue, 11 May 2021 23:01:13 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 8540D6B0073; Tue, 11 May 2021 23:01:13 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 67F386B0071; Tue, 11 May 2021 23:01:13 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0020.hostedemail.com [216.40.44.20]) by kanga.kvack.org (Postfix) with ESMTP id 46A736B006E for ; Tue, 11 May 2021 23:01:13 -0400 (EDT) Received: from smtpin35.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 0045C824999B for ; Wed, 12 May 2021 03:01:12 +0000 (UTC) X-FDA: 78131077626.35.644ECC9 Received: from szxga07-in.huawei.com (szxga07-in.huawei.com [45.249.212.35]) by imf01.hostedemail.com (Postfix) with ESMTP id 124F3500153B for ; Wed, 12 May 2021 03:01:08 +0000 (UTC) Received: from DGGEMS404-HUB.china.huawei.com (unknown [172.30.72.58]) by szxga07-in.huawei.com (SkyGuard) with ESMTP id 4Ffzxv3PLgzCrPN; Wed, 12 May 2021 10:58:27 +0800 (CST) Received: from localhost.localdomain.localdomain (10.175.113.25) by DGGEMS404-HUB.china.huawei.com (10.3.19.204) with Microsoft SMTP Server id 14.3.498.0; Wed, 12 May 2021 11:01:02 +0800 From: Kefeng Wang To: Andrew Morton CC: , , , Kefeng Wang Subject: [PATCH 3/3] mm/debug: Check page poisoned firstly in dump_page() Date: Wed, 12 May 2021 11:10:57 +0800 Message-ID: <20210512031057.13580-3-wangkefeng.wang@huawei.com> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20210512031057.13580-1-wangkefeng.wang@huawei.com> References: <20210512031057.13580-1-wangkefeng.wang@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.175.113.25] X-CFilter-Loop: Reflected Authentication-Results: imf01.hostedemail.com; dkim=none; dmarc=pass (policy=none) header.from=huawei.com; spf=pass (imf01.hostedemail.com: domain of wangkefeng.wang@huawei.com designates 45.249.212.35 as permitted sender) smtp.mailfrom=wangkefeng.wang@huawei.com X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: 124F3500153B X-Stat-Signature: 9zw4gc8aeme6tyn9df5p9kco6bq5iok5 Received-SPF: none (huawei.com>: No applicable sender policy available) receiver=imf01; identity=mailfrom; envelope-from=""; helo=szxga07-in.huawei.com; client-ip=45.249.212.35 X-HE-DKIM-Result: none/none X-HE-Tag: 1620788468-632710 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: If page is poisoned, it will crash when we call some page related functions, so must check whether the page is poisoned or not firstly. Fixes: 6197ab984b41 ("mm: improve dump_page() for compound pages") Signed-off-by: Kefeng Wang --- mm/debug.c | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-) diff --git a/mm/debug.c b/mm/debug.c index 84cdcd0f7bd3..cf84cd9df527 100644 --- a/mm/debug.c +++ b/mm/debug.c @@ -44,20 +44,19 @@ const struct trace_print_flags vmaflag_names[] = { static void __dump_page(struct page *page, const char *reason) { - struct page *head = compound_head(page); + struct page *head = NULL; struct address_space *mapping; - bool page_poisoned = PagePoisoned(page); - bool compound = PageCompound(page); + bool compound; /* * Accessing the pageblock without the zone lock. It could change to * "isolate" again in the meantime, but since we are just dumping the * state for debugging, it should be fine to accept a bit of * inaccuracy here due to racing. */ - bool page_cma = is_migrate_cma_page(page); + bool page_cma; int mapcount; char *type = ""; - + bool page_poisoned = PagePoisoned(page); /* * If struct page is poisoned don't access Page*() functions as that * leads to recursive loop. Page*() check for poisoned pages, and calls @@ -68,6 +67,10 @@ static void __dump_page(struct page *page, const char *reason) goto hex_only; } + head = compound_head(page); + page_poisoned = PagePoisoned(page); + page_cma = is_migrate_cma_page(page); + if (page < head || (page >= head + MAX_ORDER_NR_PAGES)) { /* * Corrupt page, so we cannot call page_mapping. Instead, do a @@ -178,7 +181,7 @@ static void __dump_page(struct page *page, const char *reason) print_hex_dump(KERN_WARNING, "raw: ", DUMP_PREFIX_NONE, 32, sizeof(unsigned long), page, sizeof(struct page), false); - if (head != page) + if (head && head != page) print_hex_dump(KERN_WARNING, "head: ", DUMP_PREFIX_NONE, 32, sizeof(unsigned long), head, sizeof(struct page), false);