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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5748DC636CC for ; Thu, 16 Feb 2023 20:26:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229553AbjBPU0O (ORCPT ); Thu, 16 Feb 2023 15:26:14 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44774 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229485AbjBPU0N (ORCPT ); Thu, 16 Feb 2023 15:26:13 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3B8DB2A6C2 for ; Thu, 16 Feb 2023 12:26:12 -0800 (PST) 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 E273FB829AC for ; Thu, 16 Feb 2023 20:26:10 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5DBC2C4339B; Thu, 16 Feb 2023 20:26:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1676579169; bh=vxkQYBCqGrTDGxO+NXqbzQIrCpV7K/FgvB58+L1RdUo=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=tOy7V9Fkh8AWGvLfImFPQhziAUT4qGUVizy4WDz2P/D0uFg6XDuchpdLKWoXScPhI KCQ4tCaJYalTdLGoR+cJ/o+0UyhYoyLoDcCfKFUJWeG6KLHrYc3ek3ydaYueeOVi41 NeLrOj0GkZrUHoQHOcC+jpq90IaV/Cyg9FVxXfnS0aMKqf8rHIoYb6UmN7E2P7I93A fZESA20UmsgTYJ28HfFGs14j229NkSgV2QPdvo1Cf89hnLL7/5bGZDcteqrrptHcsD cWAQokishXCkHVXreYBu7F90yT3/0HtnpnQOb5Tj5DNLf5QzRwfxzqkBIO001C3fk5 awImgMGy+eOHQ== Date: Thu, 16 Feb 2023 12:26:07 -0800 From: Josh Poimboeuf To: Dmitry Vyukov Cc: syzbot , Josh Poimboeuf , Ingo Molnar , linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com, Peter Zijlstra Subject: Re: [syzbot] WARNING: can't access registers at entry_SYSCALL_64_after_hwframe Message-ID: <20230216202607.c2nfp6exhoomjckp@treble> References: <000000000000ff304105f4d1cd36@google.com> <20230216185144.u5zijpev6o77xhaz@treble> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20230216185144.u5zijpev6o77xhaz@treble> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Feb 16, 2023 at 10:51:44AM -0800, Josh Poimboeuf wrote: > On Thu, Feb 16, 2023 at 04:14:25PM +0100, Dmitry Vyukov wrote: > > On Thu, 16 Feb 2023 at 15:13, syzbot > > wrote: > > > > > > Hello, > > > > > > syzbot found the following issue on: > > > > > > HEAD commit: 9d9019bcea1a Add linux-next specific files for 20230215 > > > git tree: linux-next > > > console output: https://syzkaller.appspot.com/x/log.txt?x=144edcc8c80000 > > > kernel config: https://syzkaller.appspot.com/x/.config?x=a64cbb8ad0da425e > > > dashboard link: https://syzkaller.appspot.com/bug?extid=dac365e3ce07c3d0e496 > > > compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2 > > > > > > Unfortunately, I don't have any reproducer for this issue yet. > > > > > > Downloadable assets: > > > disk image: https://storage.googleapis.com/syzbot-assets/70f0c6bb5351/disk-9d9019bc.raw.xz > > > vmlinux: https://storage.googleapis.com/syzbot-assets/7eed8686df34/vmlinux-9d9019bc.xz > > > kernel image: https://storage.googleapis.com/syzbot-assets/84bb6da6b00e/bzImage-9d9019bc.xz > > > > > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > > > Reported-by: syzbot+dac365e3ce07c3d0e496@syzkaller.appspotmail.com > > > > > > WARNING: can't access registers at entry_SYSCALL_64_after_hwframe+0x63/0xcd > > > > > > This is another splat of reports we started getting recently. Looks > > like this may be ORC unwinder related as well. > > Yeah... Also: > > https://lkml.kernel.org/lkml/202302161616.85f13863-oliver.sang@intel.com > https://lkml.kernel.org/lkml/CACT4Y+YzZb2vscjBLiJ-p-ghbu77o851gbESfE=nZebXqfgE4g@mail.gmail.com > > The problem seems to be commit ffb1b4a41016 ("x86/unwind/orc: Add > 'signal' field to ORC metadata") but right now I don't know why. Ah, figured it out: $ tools/objtool/objtool --dump=orc vmlinux |grep signal:1 |wc -l 0 The 'signal' bit isn't getting propagated from the unwind hints to the ORC entries :-( Will post a fix shortly. -- Josh