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 55671C4332F for ; Sun, 29 Oct 2023 09:06:01 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 2641A6B01AB; Sun, 29 Oct 2023 05:06:00 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 214746B01AE; Sun, 29 Oct 2023 05:06:00 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 0B57E6B01B1; Sun, 29 Oct 2023 05:06:00 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0015.hostedemail.com [216.40.44.15]) by kanga.kvack.org (Postfix) with ESMTP id ED8BA6B01AB for ; Sun, 29 Oct 2023 05:05:59 -0400 (EDT) Received: from smtpin09.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay01.hostedemail.com (Postfix) with ESMTP id CB4271CACAE for ; Sun, 29 Oct 2023 09:05:59 +0000 (UTC) X-FDA: 81397916838.09.0B8670C Received: from EUR03-AM7-obe.outbound.protection.outlook.com (mail-am7eur03olkn2012.outbound.protection.outlook.com [40.92.59.12]) by imf03.hostedemail.com (Postfix) with ESMTP id F260A20003 for ; Sun, 29 Oct 2023 09:05:56 +0000 (UTC) Authentication-Results: imf03.hostedemail.com; dkim=pass header.d=outlook.com header.s=selector1 header.b=Y6x7U5dJ; dmarc=pass (policy=none) header.from=outlook.com; spf=pass (imf03.hostedemail.com: domain of juntong.deng@outlook.com designates 40.92.59.12 as permitted sender) smtp.mailfrom=juntong.deng@outlook.com; arc=pass ("microsoft.com:s=arcselector9901:i=1") ARC-Message-Signature: i=2; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1698570357; 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:in-reply-to:references:references:dkim-signature; bh=BcwMR/IiMmMF1IndFxlrpqJNTzSSs2/w/qmy+PcxA3o=; b=Bnu0yC7cyTeUBztK3vcvmSwtVrVJhzmha25fCkgQF+v/kFn2gghK+ucIBfm/7QhXOlry7C uHJ7keqps5Oi61C5X1KbN8rb27mHouKtx4isbg37qbAI0fZr230hu0c/xmF990ivetPsJl AfA4455p6+lxVjG3hG2HenyCTewLafE= ARC-Authentication-Results: i=2; imf03.hostedemail.com; dkim=pass header.d=outlook.com header.s=selector1 header.b=Y6x7U5dJ; dmarc=pass (policy=none) header.from=outlook.com; spf=pass (imf03.hostedemail.com: domain of juntong.deng@outlook.com designates 40.92.59.12 as permitted sender) smtp.mailfrom=juntong.deng@outlook.com; arc=pass ("microsoft.com:s=arcselector9901:i=1") ARC-Seal: i=2; s=arc-20220608; d=hostedemail.com; t=1698570357; a=rsa-sha256; cv=pass; b=Y5iEzS2BJw/O3d5s3YXZLsfqFWwMlNNvSi+GwtZ/+zwHCa5HBoYgQXzFTaG9z9BdAjVVNa NfIF4JV/dVnuzN0nSbXOSAyqChx0oXBwXUx7DOKDsgr24eRfx9ySZigrbaU1S1ysK9wQdh acmWKTuPv8YdBbHIUQuutm8nX2aKspc= ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=LTsRuNwZWOw9s/zmBwyVsdN7ICK0E5YNWi/TQgmgvsKI6RgPc1yngVCqULzDbnJ4B019xPGyrRhGEmTh5YX2pJXY4fXGkkVflsb9gXbfPD8z1ipuYQniG1E1mH2TUsa/TRVGUp0E9cgK2AVc+VP675N3tJOyCAJJXUkoklp06rSnZqHXNNNfPNLfz8/Ia5zy9QsqoAubq/FvAHh0pJNmejPGRMUgb8g2UTc0ToZSzdmaSF2EoRC/IJdDaHIcUYEWiM+vkEfClSC+69DId8DN8zF+Zduc50hDNCZfF+oHHx8ipRj/NZDVV297yAn22s9FY/9PjnY22jYNl0bP4CWi7Q== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector9901; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-AntiSpam-MessageData-ChunkCount:X-MS-Exchange-AntiSpam-MessageData-0:X-MS-Exchange-AntiSpam-MessageData-1; bh=BcwMR/IiMmMF1IndFxlrpqJNTzSSs2/w/qmy+PcxA3o=; b=COUz0dhvyYJ/5dim8K8HgeLiJoTM8VVn/5t5na1RT35gtRuhsYLd3YucEN/4Rs8P8YYV3h896EtdE7+tuZ/nS5v9xm8NcX/EQJUBLBc4zSNUjUtjSdqZdgYtlEfYwfQe+iyHLLaX8gt/Y6DnhscpsNFArM52Pp5y0NYJNSy7BYMsItWRu7p2ft3xigu53pGoOXYkJQOeU5d6k9DmymuMiOnIByZeRIyz7LGb5NXdm7elQMJQrlKNyn2VBVnDk9UcB3MomH4cAnjroTnQfE0/VzLVpD08s2ouzD3QLtBLTVi0ewp5cBvSVDaTxGg+1h3pw7AiQdiO8g2Pil+J5cM4Mg== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=none; dmarc=none; dkim=none; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=outlook.com; s=selector1; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=BcwMR/IiMmMF1IndFxlrpqJNTzSSs2/w/qmy+PcxA3o=; b=Y6x7U5dJf1g8DPwt9h2ZpacBizQNc0GUPDCpzq16vgBXULOFVCV74UMlv3q+iJObdkBIGv1byhx5WKo0PD/MrK7A1yM7I0Dtydzrlf/qP2NWb7uqGvdVlFVKuBun0FPEEXIN8jgqBnIgKfLJcJNuxwprmuNF1+LResOH+AbyHL6B10v8ZD2kHQcSbXB3U55iYp/cjxvpBc0xgbs3wHQ0wmCI8GHBvdXLbYkPHfyVVRPK2t8YCkQZkHf+yKl32GSzTBbFob5VSmIffYh8+8zNcil27EIrR2yFtRMolhIXfS/81A53k6+0ZOk28QVrjOjztmLYPhIiWHuQFlY4Wdqtsw== Received: from VI1P193MB0752.EURP193.PROD.OUTLOOK.COM (2603:10a6:800:32::19) by AS8P193MB2301.EURP193.PROD.OUTLOOK.COM (2603:10a6:20b:446::19) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.6933.26; Sun, 29 Oct 2023 09:05:54 +0000 Received: from VI1P193MB0752.EURP193.PROD.OUTLOOK.COM ([fe80::2db3:2c11:bb43:c6e]) by VI1P193MB0752.EURP193.PROD.OUTLOOK.COM ([fe80::2db3:2c11:bb43:c6e%5]) with mapi id 15.20.6933.025; Sun, 29 Oct 2023 09:05:54 +0000 Message-ID: Date: Sun, 29 Oct 2023 17:05:54 +0800 User-Agent: Mozilla Thunderbird Subject: Re: [RFC] mm/kasan: Add Allocation, Free, Error timestamps to KASAN report To: Andrey Konovalov Cc: ryabinin.a.a@gmail.com, glider@google.com, dvyukov@google.com, vincenzo.frascino@arm.com, akpm@linux-foundation.org, kasan-dev@googlegroups.com, linux-mm@kvack.org, "linux-kernel@vger.kernel.org" , "linux-kernel-mentees@lists.linuxfoundation.org" References: From: Juntong Deng In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-TMN: [X5MALjLVTbXzlHngHlRqibWkaWE/JXzO] X-ClientProxiedBy: LO2P265CA0140.GBRP265.PROD.OUTLOOK.COM (2603:10a6:600:9f::32) To VI1P193MB0752.EURP193.PROD.OUTLOOK.COM (2603:10a6:800:32::19) X-Microsoft-Original-Message-ID: MIME-Version: 1.0 X-MS-Exchange-MessageSentRepresentingType: 1 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: VI1P193MB0752:EE_|AS8P193MB2301:EE_ X-MS-Office365-Filtering-Correlation-Id: f9e62cf3-f40d-4a8c-1997-08dbd85e4166 X-Microsoft-Antispam: BCL:0; X-Microsoft-Antispam-Message-Info: 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 X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?ZjhkT2hkNm9IMFM0WG1LVXdtRStRWlVJWnpTQk5vRkdvRkcxaHJsV1Yzd2tZ?= =?utf-8?B?WlB6ZGs4NWdFM0VEc1FSd3Zzc3JpL0p4cE1zOUI4WHhSZitsUktBWi9RMXB6?= =?utf-8?B?WnJhUUt2Yk9xRlA1d2REWGVlSFNSN3Jna3dtaXBCaHo4MmkrN3liOTNsaWNM?= =?utf-8?B?TTBRdDlkL0Mza3R3S05PSFJoMit4aGhxR3FIbkhVVjA3NlpFN1dVbEhzakJR?= =?utf-8?B?Mi9YdExyeHFiMVdCR2pBMWJPeENUUDBYRk54Q2RBSmJNN2ZhQ0ZxeHZmMEND?= =?utf-8?B?Q25wSzVQdEVnNTJKMytubitvdmxYeEQvTjJqR0Z4R0MrMTRmTE5ZNTkrL2dU?= =?utf-8?B?blR5T2RBSTJ4Z1paUGROME9GNjBwUnN5b25CSXVkcmVSckE1UEtTamw5bDBi?= =?utf-8?B?R1ZtYkVNenFYdVRwL2xuMFA1SHpwVm1ZcVh4dUFhdWFxMXpFQXo3bHhZQkpa?= =?utf-8?B?R1hNYW1vazhhR3I3YlNvWUh4eWhHajQ3a2h0Rjhuc0dLaVJFaEdNSnBCbnBa?= =?utf-8?B?YUx4YlZjRmt5ZUJLa3RZRXlaaG0yWUxld2hWUUxCZUFJaUhSdjBzL3dwREJE?= =?utf-8?B?dE5mbzVTZGVzTDRtTktrT1lhZEtMOXBOSmZxdDY0cWJyTWJoU3luVnJMcWxJ?= =?utf-8?B?MXVDd2R4L0cvNnlPV0I1MEpZRUNnMXcyZkQzNWFYMjU2M1REaVhySTdZYy82?= =?utf-8?B?REJ2S0w4VHFENmtST1ZkM1dFN2hCczkrZkdPay9pWFEwVVFDMXRlV3dqYitP?= =?utf-8?B?Z1VLTE0yUG1yY0ZzSGF0ZjlZemRKTFFQREE2NDFZSnlPcnFMREN3YVY5UWdQ?= =?utf-8?B?K1RPSEsxb0lBL3Q5OHhkbThOQmFhRE83N0JLLzQ3bXViRGgwcjdhU0Rpc01s?= =?utf-8?B?aG4xNzNGNmhObVBLUlRJZ0RPUzZBL09NZnRIN2l0NDQwVVJSYkY4c09sc0Vm?= =?utf-8?B?eTR3OWp1bDlEbDVrT2pKVmtTSDhZYkRqKzFuc2lyS2sycW1JbjJZLy90V1U1?= =?utf-8?B?K1Q3UEdob3laelZTM2lYbmdjK3R3czhjUktidkxhZ1ZTeUhBTUJqaitkNTMw?= =?utf-8?B?ZlUwblEraUY3OWFqRENwWFI5c0xzSG9rRlBrSWhhMEI0UVF6RkNLMUt0ZTMz?= =?utf-8?B?bzBYQWhuNlBORVJscWFzN1FEVFN5RDdUaERmSTFDdDh6K1NQR1lWQlN6Z3dw?= =?utf-8?B?SFdHMGlrK0F4M3NpUVhjbi9Qem1LbTc3ZHVWY0ZYdERvWVVBRzJTS1hESWJP?= =?utf-8?B?cjJHQXdobWUreEJCMXl3ZWtpVVBTaXZwdUx1RFFodmpHdzhtekRhZlNxaXBr?= =?utf-8?B?ZDVYMy9naW5lTy9UckJTNG5wTm5DeWFoMEE4QXpMMHhidURsVnBmY21BOHhF?= =?utf-8?B?emdkTitGUTNsYUI4a0tNcGRMM3lqZVVKNGpMOWtnQVFhendGNENRa2ZjUjdN?= =?utf-8?B?RE9CS2VlNm1uYk44dm5oOXFYOWdKVjVKUVY0T2NUdjV6ZVR1OUo1aVcrcENS?= =?utf-8?B?RUFWZ0tja0FpNkdrajV0Vzk1dFZQNnFqT2d5NXRvNWcrN3JtQWl6bDF3bkdO?= =?utf-8?B?YlBsSndFeFRBQ3pxRkdOakVQWldNNUQ2TmRKaUhkTWV1emZwK0NNTTVoZXJk?= =?utf-8?Q?XyCnZoD6MmDboJxROAGwAZwvdvlEctRhI7szVah+gSN0=3D?= X-OriginatorOrg: outlook.com X-MS-Exchange-CrossTenant-Network-Message-Id: f9e62cf3-f40d-4a8c-1997-08dbd85e4166 X-MS-Exchange-CrossTenant-AuthSource: VI1P193MB0752.EURP193.PROD.OUTLOOK.COM X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 29 Oct 2023 09:05:54.2744 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 84df9e7f-e9f6-40af-b435-aaaaaaaaaaaa X-MS-Exchange-CrossTenant-RMS-PersistedConsumerOrg: 00000000-0000-0000-0000-000000000000 X-MS-Exchange-Transport-CrossTenantHeadersStamped: AS8P193MB2301 X-Rspamd-Queue-Id: F260A20003 X-Rspam-User: X-Rspamd-Server: rspam02 X-Stat-Signature: 61uyymsj7kjmg1y759ki6iszuojq4hbo X-HE-Tag: 1698570356-277767 X-HE-Meta: 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 eFt380/c 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 X-Bogosity: Ham, tests=bogofilter, spamicity=0.200842, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 2023/10/26 3:22, Andrey Konovalov wrote: > On Tue, Oct 17, 2023 at 9:40 PM Juntong Deng wrote: >> >> The idea came from the bug I was fixing recently, >> 'KASAN: slab-use-after-free Read in tls_encrypt_done'. >> >> This bug is caused by subtle race condition, where the data structure >> is freed early on another CPU, resulting in use-after-free. >> >> Like this bug, some of the use-after-free bugs are caused by race >> condition, but it is not easy to quickly conclude that the cause of the >> use-after-free is race condition if only looking at the stack trace. >> >> I did not think this use-after-free was caused by race condition at the >> beginning, it took me some time to read the source code carefully and >> think about it to determine that it was caused by race condition. >> >> By adding timestamps for Allocation, Free, and Error to the KASAN >> report, it will be much easier to determine if use-after-free is >> caused by race condition. > > An alternative would be to add the CPU number to the alloc/free stack > traces. Something like: > > Allocated by task 42 on CPU 2: > (stack trace) > > The bad access stack trace already prints the CPU number. Yes, that is a great idea and the CPU number would help a lot. But I think the CPU number cannot completely replace the free timestamp, because some freeing really should be done at another CPU. We need the free timestamp to help us distinguish whether it was freed a long time ago or whether it was caused to be freed during the current operation. I think both the CPU number and the timestamp should be displayed, more information would help us find the real cause of the error faster. Should I implement these features?