From patchwork Fri Feb 4 04:49:10 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrew Morton X-Patchwork-Id: 12734789 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 E5E1EC433EF for ; Fri, 4 Feb 2022 04:49:16 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 757CF6B0074; Thu, 3 Feb 2022 23:49:16 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 706336B0075; Thu, 3 Feb 2022 23:49:16 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 5CE426B0078; Thu, 3 Feb 2022 23:49:16 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0029.hostedemail.com [216.40.44.29]) by kanga.kvack.org (Postfix) with ESMTP id 4E08C6B0074 for ; Thu, 3 Feb 2022 23:49:16 -0500 (EST) Received: from smtpin08.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id 007C596752 for ; Fri, 4 Feb 2022 04:49:15 +0000 (UTC) X-FDA: 79103868312.08.9425CC2 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by imf01.hostedemail.com (Postfix) with ESMTP id 787CA40003 for ; Fri, 4 Feb 2022 04:49:15 +0000 (UTC) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 57672B8366B; Fri, 4 Feb 2022 04:49:14 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 75F58C004E1; Fri, 4 Feb 2022 04:49:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1643950153; bh=T6HZzuF9kGoCDs+xTHJbPxAXenTBHTFYjDOPtEfogn0=; h=Date:To:From:In-Reply-To:Subject:From; b=pRtMXnfQgDH4cec97TvEXBzcUrEgQdiqZrqQg/QlHoigq+4M++UcCfiip4dbAqczf ntmVRfvP+eM6ebJOTyUZPypJz7poKn/nOZhBPWSRvsZ96MZe31sCrSDBxd0sP+05vE wR15nCGANM54UIPLffV7Bwf8KhLvEileBO4Hrk0w= Received: by hp1 (sSMTP sendmail emulation); Thu, 03 Feb 2022 20:49:10 -0800 Date: Thu, 03 Feb 2022 20:49:10 -0800 To: ziy@nvidia.com,will@kernel.org,weixugc@google.com,stable@vger.kernel.org,songmuchun@bytedance.com,rppt@kernel.org,rientjes@google.com,pjt@google.com,mingo@redhat.com,jirislaby@kernel.org,hughd@google.com,hpa@zytor.com,gthelen@google.com,dave.hansen@linux.intel.com,anshuman.khandual@arm.com,aneesh.kumar@linux.ibm.com,pasha.tatashin@soleen.com,akpm@linux-foundation.org,linux-mm@kvack.org,mm-commits@vger.kernel.org,torvalds@linux-foundation.org,akpm@linux-foundation.org From: Andrew Morton In-Reply-To: <20220203204836.88dcebe504f440686cc63a60@linux-foundation.org> Subject: [patch 02/10] mm/debug_vm_pgtable: remove pte entry from the page table Message-Id: <20220204044911.75F58C004E1@smtp.kernel.org> X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: 787CA40003 X-Rspam-User: nil Authentication-Results: imf01.hostedemail.com; dkim=pass header.d=linux-foundation.org header.s=korg header.b=pRtMXnfQ; dmarc=none; spf=pass (imf01.hostedemail.com: domain of akpm@kernel.org designates 145.40.68.75 as permitted sender) smtp.mailfrom=akpm@kernel.org X-Stat-Signature: ksiod9gt4sk7xr1yodyxtrdwdynh4tmw X-HE-Tag: 1643950155-57000 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: Pasha Tatashin Subject: mm/debug_vm_pgtable: remove pte entry from the page table Patch series "page table check fixes and cleanups", v5. This patch (of 4): The pte entry that is used in pte_advanced_tests() is never removed from the page table at the end of the test. The issue is detected by page_table_check, to repro compile kernel with the following configs: CONFIG_DEBUG_VM_PGTABLE=y CONFIG_PAGE_TABLE_CHECK=y CONFIG_PAGE_TABLE_CHECK_ENFORCED=y During the boot the following BUG is printed: [ 2.262821] debug_vm_pgtable: [debug_vm_pgtable ]: Validating architecture page table helpers [ 2.276826] ------------[ cut here ]------------ [ 2.280426] kernel BUG at mm/page_table_check.c:162! [ 2.284118] invalid opcode: 0000 [#1] PREEMPT SMP PTI [ 2.287787] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.16.0-11413-g2c271fe77d52 #3 [ 2.293226] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.15.0-0-g2dd4b9b3f840-prebuilt.qemu.org 04/01/2014 ... The entry should be properly removed from the page table before the page is released to the free list. Link: https://lkml.kernel.org/r/20220131203249.2832273-1-pasha.tatashin@soleen.com Link: https://lkml.kernel.org/r/20220131203249.2832273-2-pasha.tatashin@soleen.com Fixes: a5c3b9ffb0f4 ("mm/debug_vm_pgtable: add tests validating advanced arch page table helpers") Signed-off-by: Pasha Tatashin Reviewed-by: Zi Yan Tested-by: Zi Yan Acked-by: David Rientjes Reviewed-by: Anshuman Khandual Cc: Paul Turner Cc: Wei Xu Cc: Greg Thelen Cc: Ingo Molnar Cc: Will Deacon Cc: Mike Rapoport Cc: Dave Hansen Cc: H. Peter Anvin Cc: Aneesh Kumar K.V Cc: Jiri Slaby Cc: Muchun Song Cc: Hugh Dickins Cc: [5.9+] Signed-off-by: Andrew Morton --- mm/debug_vm_pgtable.c | 2 ++ 1 file changed, 2 insertions(+) --- a/mm/debug_vm_pgtable.c~mm-debug_vm_pgtable-remove-pte-entry-from-the-page-table +++ a/mm/debug_vm_pgtable.c @@ -171,6 +171,8 @@ static void __init pte_advanced_tests(st ptep_test_and_clear_young(args->vma, args->vaddr, args->ptep); pte = ptep_get(args->ptep); WARN_ON(pte_young(pte)); + + ptep_get_and_clear_full(args->mm, args->vaddr, args->ptep, 1); } static void __init pte_savedwrite_tests(struct pgtable_debug_args *args)