From patchwork Thu Jan 20 04:25:11 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pasha Tatashin X-Patchwork-Id: 12718245 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 92384C433F5 for ; Thu, 20 Jan 2022 04:25:19 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id AF7406B00BE; Wed, 19 Jan 2022 23:25:18 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id ACFEC6B00C3; Wed, 19 Jan 2022 23:25:18 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 9A1906B00BE; Wed, 19 Jan 2022 23:25:18 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0157.hostedemail.com [216.40.44.157]) by kanga.kvack.org (Postfix) with ESMTP id 8B3BB6B00BE for ; Wed, 19 Jan 2022 23:25:18 -0500 (EST) Received: from smtpin23.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 3A188951B3 for ; Thu, 20 Jan 2022 04:25:18 +0000 (UTC) X-FDA: 79049375916.23.A17E247 Received: from mail-qt1-f175.google.com (mail-qt1-f175.google.com [209.85.160.175]) by imf15.hostedemail.com (Postfix) with ESMTP id D87C4A000B for ; Thu, 20 Jan 2022 04:25:17 +0000 (UTC) Received: by mail-qt1-f175.google.com with SMTP id 14so4315348qty.2 for ; Wed, 19 Jan 2022 20:25:17 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=soleen.com; s=google; h=from:to:subject:date:message-id:in-reply-to:references:mime-version :content-transfer-encoding; bh=BRQvkyJfLwToXuPc9CF9KmCDMc31zinjyrsWOern8Tg=; b=nJDYI+ciV99Z/2F42EEsoomiaC+ya+hPY7wXcTLaV8orJZZj9z3SMp/plXHCWl5cS1 CjalBl/ubSwiXr07vJolWHPVQsCQxXmvj7C9W4XP4ZKfKKvPlFdnmmyrkA6tSHcWFUwt +lqzXkTC/TqMCbCJ30bsNb+vs9/4Jz/LSZsutlbldHGW3bNNjJD/M1DCsO0d9IJvSKg7 nK5WnQ/nOaERaP9v3ERmIwRCacKEiK0XayC8pzXoHN9cwj8fLscp5sAVzEeciyBkD+F0 xyYG9r3oxse8h/o6fEtLDgoYwtzVmiUcgRmx41gp5q9hXwb1tUxW4UJn3QOtC5HZwuhg prCw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=BRQvkyJfLwToXuPc9CF9KmCDMc31zinjyrsWOern8Tg=; b=lQrMZPfyjGpkU6mGHm1knSM5zWBV4Q9wal3DX6lT9gtFJEr+bbd+xmymr8rzmZFeOW xd1drWlUAVg/1t6bX09M7RwAuOyycnVdE2IJu/VViOTIq7nNQkwAc2T/Zyx8e1R2cLD7 2T/b6tNx4XYBU7hLT5nKVf1MmIIsP3s3pv5ALUMeaOXVh0eZt/LKcLNaE2/J/VmMNKDe rxFjKKfZam/wfj1wu1YT3hLkYyRpFVxsq5Iwr9RaT0BrtkkKPK2SJ5ED7ZsewoeCRDmE vj5sZNye8sMZTuZhRJoLxRr5zpX+AuRX+GwYRPdFY8eEUnwHZqiX7k4CeIKq2gAzKY/s 2j6w== X-Gm-Message-State: AOAM533yTg9GxUPoG9pLp43WB6g3JkJdcCdcm9gxsZDxkP5fPRR05PVq fz6xozjSrUNSoOTL6X0/uxJ3Vw== X-Google-Smtp-Source: ABdhPJwPUQaGDfTZBgEZrsyNqiqF3s5J39OTgoUAisRbJTqg5M+ibUW/EknbldLh2q9bXECqc7BGFA== X-Received: by 2002:a05:622a:3cd:: with SMTP id k13mr14439260qtx.458.1642652717142; Wed, 19 Jan 2022 20:25:17 -0800 (PST) Received: from soleen.c.googlers.com.com (189.216.85.34.bc.googleusercontent.com. [34.85.216.189]) by smtp.gmail.com with ESMTPSA id n22sm927228qka.46.2022.01.19.20.25.16 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 19 Jan 2022 20:25:16 -0800 (PST) From: Pasha Tatashin To: pasha.tatashin@soleen.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, akpm@linux-foundation.org, rientjes@google.com, pjt@google.com, weixugc@google.com, gthelen@google.com, mingo@redhat.com, will@kernel.org, rppt@kernel.org, dave.hansen@linux.intel.com, hpa@zytor.com, aneesh.kumar@linux.ibm.com, jirislaby@kernel.org, songmuchun@bytedance.com, qydwhotmail@gmail.com, hughd@google.com, ziy@nvidia.com, anshuman.khandual@arm.com Subject: [PATCH 1/3] mm/debug_vm_pgtable: remove pte entry from the page table Date: Thu, 20 Jan 2022 04:25:11 +0000 Message-Id: <20220120042513.1648831-2-pasha.tatashin@soleen.com> X-Mailer: git-send-email 2.34.1.703.g22d0c6ccf7-goog In-Reply-To: <20220120042513.1648831-1-pasha.tatashin@soleen.com> References: <20220120042513.1648831-1-pasha.tatashin@soleen.com> MIME-Version: 1.0 X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: D87C4A000B X-Stat-Signature: wo8bd41u3s4b7bd3fowejk1qjmun7rbj Authentication-Results: imf15.hostedemail.com; dkim=pass header.d=soleen.com header.s=google header.b=nJDYI+ci; spf=pass (imf15.hostedemail.com: domain of pasha.tatashin@soleen.com designates 209.85.160.175 as permitted sender) smtp.mailfrom=pasha.tatashin@soleen.com; dmarc=none X-HE-Tag: 1642652717-620967 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 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: [ 7.483050][ T1] debug_vm_pgtable: [debug_vm_pgtable ]: Validating architecture page tabs [ 7.490930][ T1] ------------[ cut here ]------------ [ 7.494926][ T1] kernel BUG at mm/page_table_check.c:194! [ 7.499172][ T1] invalid opcode: 0000 [#1] PREEMPT SMP KASAN [ 7.503610][ T1] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.16.0+ [ 7.508600][ T1] Hardware name: QEMU Standard PC (i440FX + PIIX, ... The entry should be properly removed from the page table before the page is released to the free list. Fixes: a5c3b9ffb0f4 ("mm/debug_vm_pgtable: add tests validating advanced arch page table helpers") Signed-off-by: Pasha Tatashin Reviewed-by: Zi Yan and Tested-by: Zi Yan --- mm/debug_vm_pgtable.c | 1 + 1 file changed, 1 insertion(+) diff --git a/mm/debug_vm_pgtable.c b/mm/debug_vm_pgtable.c index a7ac97c76762..f7c5970f1719 100644 --- a/mm/debug_vm_pgtable.c +++ b/mm/debug_vm_pgtable.c @@ -171,6 +171,7 @@ static void __init pte_advanced_tests(struct pgtable_debug_args *args) 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)