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 X-Spam-Level: X-Spam-Status: No, score=-7.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5CE0AC4361B for ; Fri, 18 Dec 2020 06:55:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2720D22CB8 for ; Fri, 18 Dec 2020 06:55:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732869AbgLRGzX (ORCPT ); Fri, 18 Dec 2020 01:55:23 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46758 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725860AbgLRGzX (ORCPT ); Fri, 18 Dec 2020 01:55:23 -0500 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AFE00C0617A7 for ; Thu, 17 Dec 2020 22:54:42 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=Content-Transfer-Encoding:Content-Type: In-Reply-To:MIME-Version:Date:Message-ID:From:References:Cc:To:Subject:Sender :Reply-To:Content-ID:Content-Description; bh=eVSNY9beUisrR6DjTzyXH++4TmxxcaQeUDEUADAgt1U=; b=Xh9i/7r3Q7CTC43D9D6U4TBeLw zbsXVO3dGc/0kXabTzkzBxWo6nkH4P+9vqohUSsYuuEEyrTc29TMPeJqPfYDN9MGaND6J6JN/Zudn 0+BVcxITXS+1/+mIMlg/AnljIuS0yDuEQeQNGZXjz3sh1j1VcQbRAsDNQfG56w8tCePWoKwX1KzJN dNHkVtlOS36acsz1CwafDFRdmcKXur3zgvz3r70kfhQUi4uANuKi26r/YxxGCExy8/oxr55YpcQnO m6X8yxxLstkn7d+VibZhl4mT/VnThtX5Z6zvukWe66Wx0t4R1ogIsm5QbWam6Bwk+C1q6L83TqiyJ DxDJL9Sg==; Received: from [2601:1c0:6280:3f0::64ea] by casper.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1kq9ex-0005O4-Fu; Fri, 18 Dec 2020 06:54:39 +0000 Subject: Re: 5.10.1: UBSAN: shift-out-of-bounds in ./include/linux/log2.h:57:1 To: =?UTF-8?Q?Toralf_F=c3=b6rster?= , jgg@ziepe.ca Cc: Linux Kernel , Linux MM References: From: Randy Dunlap Message-ID: <5c172fad-a9cf-c29d-0a27-f2b0505dc33d@infradead.org> Date: Thu, 17 Dec 2020 22:54:35 -0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.4.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, [adding linux-mm] On 12/16/20 1:54 AM, Toralf Förster wrote: > Hi, > > I got this recently at this hardened Gentoo Linux server: > > Linux mr-fox 5.10.1 #1 SMP Tue Dec 15 22:09:42 CET 2020 x86_64 Intel(R) > Xeon(R) CPU E5-1650 v3 @ 3.50GHz GenuineIntel GNU/Linux > > > Dec 15 23:31:51 mr-fox kernel: [ 1974.206972] > ================================================================================ > Dec 15 23:31:51 mr-fox kernel: [ 1974.206977] UBSAN: shift-out-of-bounds > in ./include/linux/log2.h:57:13 > Dec 15 23:31:51 mr-fox kernel: [ 1974.206980] shift exponent 64 is too > large for 64-bit type 'long unsigned int' > Dec 15 23:31:51 mr-fox kernel: [ 1974.206982] CPU: 11 PID: 21051 Comm: > cc1 Tainted: G                T 5.10.1 #1 > Dec 15 23:31:51 mr-fox kernel: [ 1974.206984] Hardware name: ASUSTeK > COMPUTER INC. Z10PA-U8 Series/Z10PA-U8 Series, BIOS 3703 08/02/2018 > Dec 15 23:31:51 mr-fox kernel: [ 1974.206985] Call Trace: > Dec 15 23:31:51 mr-fox kernel: [ 1974.206993]  dump_stack+0x57/0x6a > Dec 15 23:31:51 mr-fox kernel: [ 1974.206996]  ubsan_epilogue+0x5/0x40 > Dec 15 23:31:51 mr-fox kernel: [ 1974.206999] > __ubsan_handle_shift_out_of_bounds.cold+0x61/0x10e > Dec 15 23:31:51 mr-fox kernel: [ 1974.207002] > ondemand_readahead.cold+0x16/0x21 > Dec 15 23:31:51 mr-fox kernel: [ 1974.207007] > generic_file_buffered_read+0x452/0x890 > Dec 15 23:31:51 mr-fox kernel: [ 1974.207011]  new_sync_read+0x156/0x200 > Dec 15 23:31:51 mr-fox kernel: [ 1974.207014]  vfs_read+0xf8/0x190 > Dec 15 23:31:51 mr-fox kernel: [ 1974.207016]  ksys_read+0x65/0xe0 > Dec 15 23:31:51 mr-fox kernel: [ 1974.207018]  do_syscall_64+0x33/0x40 > Dec 15 23:31:51 mr-fox kernel: [ 1974.207021] > entry_SYSCALL_64_after_hwframe+0x44/0xa9 > Dec 15 23:31:51 mr-fox kernel: [ 1974.207024] RIP: 0033:0x7f01b2df198e > Dec 15 23:31:51 mr-fox kernel: [ 1974.207026] Code: c0 e9 b6 fe ff ff 50 > 48 8d 3d 66 c3 09 00 e8 59 e2 01 00 66 0f 1f 84 00 00 00 00 00 64 8b 04 > 25 18 00 00 00 85 c0 75 14 0f 05 <48> 3d 00 f0 ff ff 77 5a c3 66 0f 1f > 84 00 00 00 00 00 48 83 ec 28 > Dec 15 23:31:51 mr-fox kernel: [ 1974.207028] RSP: 002b:00007fff2167e998 > EFLAGS: 00000246 ORIG_RAX: 0000000000000000 > Dec 15 23:31:51 mr-fox kernel: [ 1974.207030] RAX: ffffffffffffffda RBX: > 0000000000000000 RCX: 00007f01b2df198e > Dec 15 23:31:51 mr-fox kernel: [ 1974.207032] RDX: 0000000000000000 RSI: > 00000000054dcc50 RDI: 0000000000000004 > Dec 15 23:31:51 mr-fox kernel: [ 1974.207033] RBP: 00000000054dcc50 R08: > 00000000054dcc50 R09: 0000000000000000 > Dec 15 23:31:51 mr-fox kernel: [ 1974.207034] R10: 0000000000000000 R11: > 0000000000000246 R12: 00000000054dc3b0 > Dec 15 23:31:51 mr-fox kernel: [ 1974.207035] R13: 0000000000008000 R14: > 00000000054c9800 R15: 0000000000000000 > Dec 15 23:31:51 mr-fox kernel: [ 1974.207037] > ================================================================================ > > > Known issue ? Not that I have heard about, but that's not conclusive. Looks to me like this is in mm/readahead.c: static unsigned long get_init_ra_size(unsigned long size, unsigned long max) { unsigned long newsize = roundup_pow_of_two(size); What filesystem? What workload? thanks. -- ~Randy