From patchwork Tue Oct 25 01:42:15 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: mawupeng X-Patchwork-Id: 13018396 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 56EE2C67871 for ; Tue, 25 Oct 2022 01:16:40 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id DDB008000A; Mon, 24 Oct 2022 21:16:39 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id D8B6380007; Mon, 24 Oct 2022 21:16:39 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id C7ADE8000A; Mon, 24 Oct 2022 21:16:39 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0016.hostedemail.com [216.40.44.16]) by kanga.kvack.org (Postfix) with ESMTP id BAD6080007 for ; Mon, 24 Oct 2022 21:16:39 -0400 (EDT) Received: from smtpin19.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay05.hostedemail.com (Postfix) with ESMTP id 8AC4640302 for ; Tue, 25 Oct 2022 01:16:39 +0000 (UTC) X-FDA: 80057706918.19.D7DE1E6 Received: from szxga03-in.huawei.com (szxga03-in.huawei.com [45.249.212.189]) by imf13.hostedemail.com (Postfix) with ESMTP id C248620011 for ; Tue, 25 Oct 2022 01:16:37 +0000 (UTC) Received: from dggpemm500022.china.huawei.com (unknown [172.30.72.53]) by szxga03-in.huawei.com (SkyGuard) with ESMTP id 4MxDV40xqfzJn9K; Tue, 25 Oct 2022 09:13:48 +0800 (CST) Received: from dggpemm500014.china.huawei.com (7.185.36.153) by dggpemm500022.china.huawei.com (7.185.36.162) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.31; Tue, 25 Oct 2022 09:16:33 +0800 Received: from localhost.localdomain (10.175.112.125) by dggpemm500014.china.huawei.com (7.185.36.153) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.31; Tue, 25 Oct 2022 09:16:32 +0800 From: Wupeng Ma To: , , CC: , , , , , Subject: [PATCH -next 1/1] mm: hugetlb_vmemmap: Fix WARN_ON in vmemmap_remap_pte Date: Tue, 25 Oct 2022 09:42:15 +0800 Message-ID: <20221025014215.3466904-1-mawupeng1@huawei.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 X-Originating-IP: [10.175.112.125] X-ClientProxiedBy: dggems702-chm.china.huawei.com (10.3.19.179) To dggpemm500014.china.huawei.com (7.185.36.153) X-CFilter-Loop: Reflected ARC-Authentication-Results: i=1; imf13.hostedemail.com; dkim=none; spf=pass (imf13.hostedemail.com: domain of mawupeng1@huawei.com designates 45.249.212.189 as permitted sender) smtp.mailfrom=mawupeng1@huawei.com; dmarc=pass (policy=quarantine) header.from=huawei.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1666660599; a=rsa-sha256; cv=none; b=0/6AEN7pUUb3jbPJWeeDmBbsUxCn05wIYW2eTDSNMKuBl8qBZLrcPu5Z1JBES8C6Ioj5tg StHcuGgX0aMYKWMpFK7+h1vloTEgx+zuqGJ+0M3o0TT51x/TOyr2zXQjxiQiIfsx81EYGY oj0K4v5l43BoLV06xf3d0TPF4kOjrNI= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1666660599; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding:in-reply-to: references; bh=HKXL7MOf6FOmE0SQk8hzscD/pjlbsYSybuO3jeAflUs=; b=ke5UGNLSDoK+AAfPiNx+K1Jfc6MTCu8sCKRngPgNNRKx8Twvg2JQFhp7DIveeKd4IFEeiI sSDfALasVK2aQM71pO0cu/PlAvmK5oNBwJNhapsjDG24Mp71qwhJG8Xs+XerrAp/pMFdY6 CXgGHriYVf1APR2c8UpsVUvZS4XAVf4= X-Rspamd-Queue-Id: C248620011 Authentication-Results: imf13.hostedemail.com; dkim=none; spf=pass (imf13.hostedemail.com: domain of mawupeng1@huawei.com designates 45.249.212.189 as permitted sender) smtp.mailfrom=mawupeng1@huawei.com; dmarc=pass (policy=quarantine) header.from=huawei.com X-Rspamd-Server: rspam02 X-Rspam-User: X-Stat-Signature: ycgiwt8z7t9csq9jef6fq4t6j8jfxnbg X-HE-Tag: 1666660597-907798 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: From: Ma Wupeng Commit f41f2ed43ca5 ("mm: hugetlb: free the vmemmap pages associated with each HugeTLB page") add vmemmap_remap_pte to remap the tail pages as read-only to catch illegal write operation to the tail page. However this will lead to WARN_ON in arm64 in __check_racy_pte_update() since this may lead to dirty state cleaned. This check is introduced by commit 2f4b829c625e ("arm64: Add support for hardware updates of the access and dirty pte bits") and the initial check is as follow: BUG_ON(pte_write(*ptep) && !pte_dirty(pte)); Since we do need to mark this pte as read-only to catch illegal write operation to the tail pages, use set_pte to replace set_pte_at to bypass this check. The following shell command can be used to reproduce this WARN_ON in 6.1.0-rc1: echo 1 > /proc/sys/vm/hugetlb_optimize_vmemmap cat /proc/sys/vm/hugetlb_optimize_vmemmap echo 1024 > /proc/sys/vm/nr_overcommit_hugepages mkdir -p /root/hugetlb mount none /root/hugetlb -t hugetlbfs fallocate -l 2g /root/hugetlb/xx & Here is the detail WARN_ON log: ------------[ cut here ]------------ __check_racy_pte_update: racy dirty state clearing: 0x0068000416899f03 -> 0x0060000416898f83 WARNING: CPU: 3 PID: 394 at arch/arm64/include/asm/pgtable.h:318 vmemmap_remap_pte+0x118/0x120 Modules linked in: CPU: 3 PID: 394 Comm: fallocate Not tainted 6.1.0-rc1 #224 Hardware name: QEMU QEMU Virtual Machine, BIOS 0.0.0 02/06/2015 Call trace: vmemmap_remap_pte+0x118/0x120 vmemmap_remap_range+0x30c/0x560 hugetlb_vmemmap_optimize+0x158/0x408 __prep_new_huge_page+0x24/0x150 prep_new_huge_page+0x30/0x60 alloc_fresh_huge_page+0x1c4/0x1e0 alloc_surplus_huge_page+0xa0/0x168 alloc_huge_page+0x264/0x5b8 hugetlbfs_fallocate+0x294/0x680 vfs_fallocate+0x12c/0x568 ksys_fallocate+0x50/0xa0 __arm64_sys_fallocate+0x28/0x38 invoke_syscall+0x4c/0x110 el0_svc_common.constprop.0+0x68/0x128 do_el0_svc+0x34/0xd0 el0_svc+0x48/0xb8 el0t_64_sync_handler+0xb8/0xc0 el0t_64_sync+0x18c/0x190 ---[ end trace 0000000000000000 ]--- Fixes: f41f2ed43ca5 ("mm: hugetlb: free the vmemmap pages associated with each HugeTLB page") Signed-off-by: Ma Wupeng --- mm/hugetlb_vmemmap.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/hugetlb_vmemmap.c b/mm/hugetlb_vmemmap.c index ba2a2596fb4e..cb056265c31e 100644 --- a/mm/hugetlb_vmemmap.c +++ b/mm/hugetlb_vmemmap.c @@ -249,7 +249,7 @@ static void vmemmap_remap_pte(pte_t *pte, unsigned long addr, struct page *page = pte_page(*pte); list_add_tail(&page->lru, walk->vmemmap_pages); - set_pte_at(&init_mm, addr, pte, entry); + set_pte(pte, entry); } /*