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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8DE49C433EF for ; Fri, 19 Nov 2021 02:07:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 69A0961AE2 for ; Fri, 19 Nov 2021 02:07:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233872AbhKSCKz (ORCPT ); Thu, 18 Nov 2021 21:10:55 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33842 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231802AbhKSCKy (ORCPT ); Thu, 18 Nov 2021 21:10:54 -0500 Received: from mail-pg1-x530.google.com (mail-pg1-x530.google.com [IPv6:2607:f8b0:4864:20::530]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 53784C061574 for ; Thu, 18 Nov 2021 18:07:53 -0800 (PST) Received: by mail-pg1-x530.google.com with SMTP id 28so7220462pgq.8 for ; Thu, 18 Nov 2021 18:07:53 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=/E5YbLCgj0qYAmaRMzm+csLlxRRBB6J73kLY09p9kMA=; b=Scpjwb7CfQN41UBUFwKVHsu+sTysCuIwCWRrnCa/jZDn5dl7+nQZA27ZbVnY3eMF9v 4EuXQ+6AchxIZpgpdAGqhEBj12HtMAtKSGcunbD/5w5mGd8U5ZJty3nQTrDFPF6rAvg5 I0zFmUpQxF7d8TLHEs6933OOGsEXw0Boe4G/Y= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=/E5YbLCgj0qYAmaRMzm+csLlxRRBB6J73kLY09p9kMA=; b=4RH4Ly4jKG75LNHeh+rpBpfUUXCMd6+BUbrk7bVawGj7PJQRbDGEDUg9DfIk7YZhEi bVoqr4eHjIX2UoJbAA7QqI0C3AKsGPnqv8/IXI6oOHzmp//I2B8eWwmiX13fqjfWlgeh qbtFrz+M0C7NygT2trp9SXzPkdE4Qu2GtN1QJX9I6jgNDAT5vMRauqF0fu1s6tajb82F gOwF/x1l+Uh3I1tmTmZxIHMnmjjtcCiwY+sX2+pMMfW8wN7IALIi7+vS2QOTq+bI5VGF 0pe4mukScg9O+JG/xDbZU4OHtkpm2SSVSgUnLVDNCJ4Exgc2YtT/BQ/1QPZ6QOt74m7q E3FQ== X-Gm-Message-State: AOAM531bJvBL3svxjwkAU3YeFZHWl8rvY1b2UOK1kx60pyfNhthozV4G Urs5ChvqGdBixnLTQJN6axjs0g== X-Google-Smtp-Source: ABdhPJw5qWjzDItxnffOwBfIoPka7CSIpAIa7NqjP5EFsdVpj4otr00Z/3WiKXX02KrcNqSVU6KTEg== X-Received: by 2002:a63:8bca:: with SMTP id j193mr13138617pge.231.1637287672847; Thu, 18 Nov 2021 18:07:52 -0800 (PST) Received: from google.com ([240f:75:7537:3187:f3c1:d25d:4dc6:f786]) by smtp.gmail.com with ESMTPSA id p17sm678080pgj.93.2021.11.18.18.07.49 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 18 Nov 2021 18:07:52 -0800 (PST) Date: Fri, 19 Nov 2021 11:07:47 +0900 From: Sergey Senozhatsky To: Dan Williams Cc: Sergey Senozhatsky , "Kirill A. Shutemov" , Jeff Moyer , Andrea Arcangeli , Suren Baghdasaryan , Andrew Morton , Linux Kernel Mailing List , Linux MM Subject: Re: mm: gdb fails if binary is on a DAX-enabled filesystem Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On (21/11/18 17:35), Dan Williams wrote: > > We are running into issues on a DAX enabled system: both > > __copy_from_user_inatomic() fail. > > > > [ 28.914865] ------------[ cut here ]------------ > > [ 28.915800] WARNING: CPU: 0 PID: 106 at mm/memory.c:2822 wp_page_copy+0x136/0x320 > > [ 28.916857] CPU: 0 PID: 106 Comm: gdb Not tainted 5.15.0-01277-g6be711548944 #1 > > [ 28.917823] Hardware name: ChromiumOS crosvm, BIOS 0 > > [ 28.918455] RIP: 0010:wp_page_copy+0x136/0x320 > > [ 28.919001] Code: f1 79 00 4c 89 7b 50 48 8b 43 38 31 d2 49 39 07 75 23 48 8b 7d c8 48 8b 75 c0 ba 00 10 00 00 e8 6f 23 78 00 b2 01 85 c0 74 0b <0f> 0b 48 8b 7d c8 e8 8e 1f 78 00 48 8b 7b 58 88 55 c8 e8 2e f2 79 > > [ 28.920642] RSP: 0018:ffffc900005dfbd8 EFLAGS: 00010206 > > [ 28.921135] RAX: 0000000000001000 RBX: ffffc900005dfc40 RCX: 0000000000001000 > > [ 28.921762] RDX: 0000000000001001 RSI: 0000000000448000 RDI: ffff8880007bb000 > > [ 28.922410] RBP: ffffc900005dfc28 R08: ffff8880031884c8 R09: 0000000000000000 > > [ 28.923058] R10: ffff88800f8234c8 R11: 0000000000000000 R12: ffffea000001eec0 > > [ 28.923718] R13: 0000000000000000 R14: ffff88800e18e630 R15: ffff888000884240 > > [ 28.924404] FS: 00007e5b49744180(0000) GS:ffff88800f800000(0000) knlGS:0000000000000000 > > [ 28.925146] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > > [ 28.925688] CR2: 0000000000448000 CR3: 000000000e0d6000 CR4: 0000000000350eb0 > > [ 28.926368] Call Trace: > > [ 28.926622] __handle_mm_fault+0x67e/0xbd7 > > [ 28.927018] handle_mm_fault+0x16b/0x23d > > [ 28.927390] __get_user_pages+0x2d6/0x4b7 > > [ 28.927797] __get_user_pages_remote+0xbe/0x20c > > [ 28.928224] __access_remote_vm+0xb3/0x1c8 > > [ 28.928655] ptrace_access_vm+0x97/0xb0 > > [ 28.929036] generic_ptrace_pokedata+0x22/0x31 > > [ 28.929452] arch_ptrace+0x1ce/0x1dd > > [ 28.929801] __do_sys_ptrace+0xa9/0xda > > [ 28.930161] do_syscall_64+0x75/0x8b > > [ 28.930511] entry_SYSCALL_64_after_hwframe+0x44/0xae > > [ 28.930996] RIP: 0033:0x7e5b4c86fe5a > > [ 28.931332] Code: 70 41 83 f8 03 c7 44 24 10 08 00 00 00 48 89 44 24 18 48 8d 44 24 30 8b 70 08 4c 0f 43 d1 48 89 44 24 20 b8 65 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 3e 48 85 c0 78 06 41 83 f8 02 76 1b 48 8b 4c > > [ 28.933086] RSP: 002b:00007ffdc3369150 EFLAGS: 00000202 ORIG_RAX: 0000000000000065 > > [ 28.933767] RAX: ffffffffffffffda RBX: 0000000000448620 RCX: 00007e5b4c86fe5a > > [ 28.934476] RDX: 0000000000448620 RSI: 000000000000006d RDI: 0000000000000005 > > [ 28.935206] RBP: 0000000000000001 R08: 0000000000000004 R09: 0000000000448620 > > [ 28.935916] R10: 00841f0f2e6666cc R11: 0000000000000202 R12: 0000000000000001 > > [ 28.936672] R13: 00841f0f2e6666cc R14: 0000000000000000 R15: 00007e5b49743958 > > [ 28.937389] ---[ end trace 2808c0ffd7259839 ]--- > > Program received signal SIGSEGV, Segmentation fault. > > > > Is there anything we can do about it? > > I'll take a look, can you send a bit more info about your > configuration? Which filesystem, and which driver is providing the dax > access? The 'shared' directory is on ext4 on the host and is mounted in the guest VM as mount -t virtiofs -o dax shared /mnt