From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751529AbdB1SOe (ORCPT ); Tue, 28 Feb 2017 13:14:34 -0500 Received: from bh-25.webhostbox.net ([208.91.199.152]:44765 "EHLO bh-25.webhostbox.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751356AbdB1SOa (ORCPT ); Tue, 28 Feb 2017 13:14:30 -0500 Date: Tue, 28 Feb 2017 10:14:13 -0800 From: Guenter Roeck To: Sandra Loosemore Cc: Tobias Klauser , Sven Schmidt <4sschmid@informatik.uni-hamburg.de>, Arnd Bergmann , Andrew Morton , linux-kernel@vger.kernel.org, Ley Foon Tan , nios2-dev@lists.rocketboards.org Subject: Re: nios2 crash/hang in mainline due to 'lib: update LZ4 compressor module' Message-ID: <20170228181413.GC13455@roeck-us.net> References: <20170226210338.GA19476@roeck-us.net> <20170228155331.GC27998@distanz.ch> <58B5B934.5040807@codesourcery.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <58B5B934.5040807@codesourcery.com> User-Agent: Mutt/1.5.24 (2015-08-30) X-Authenticated_sender: guenter@roeck-us.net X-OutGoing-Spam-Status: No, score=-1.0 X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - bh-25.webhostbox.net X-AntiAbuse: Original Domain - vger.kernel.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - roeck-us.net X-Get-Message-Sender-Via: bh-25.webhostbox.net: authenticated_id: guenter@roeck-us.net X-Authenticated-Sender: bh-25.webhostbox.net: guenter@roeck-us.net X-Source: X-Source-Args: X-Source-Dir: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Feb 28, 2017 at 10:53:56AM -0700, Sandra Loosemore wrote: > On 02/28/2017 08:53 AM, Tobias Klauser wrote: > >(adding Sandra Loosemore to Cc due to possible relation to gcc/binutils > >for nios2) > > > >On 2017-02-26 at 22:03:38 +0100, Guenter Roeck wrote: > >>Hi Sven, > >> > >>my qemu test for nios2 started failing with commit 4e1a33b105dd ("lib: > >>update LZ4 compressor module"). The test hangs early during boot before > >>any console output is seen. Reverting the offending patch as well as the > >>subsequent lz4 related patches fixes the problem. Disabling CONFIG_RD_LZ4 > >>and with it other LZ4 options also fixes it (as does adding "return -EINVAL;" > >>at the top of the LZ4 decompression code). For reference, bisect log > >>is attached. > >> > >>I tried with buildroot toolchains using gcc 6.1.0 as well as 6.3.0 > >>and binutils 2.26.1. Scripts used to run the tests are available at > >>https://github.com/groeck/linux-build-test/tree/master/rootfs/nios2. > >>Qemu is from qemu mainline or qemu v2.8 with nios2 patches applied. > > > >Looks like this is somehow related to gcc/binutils. Using GCC 4.8.3 and > >binutils 2.24.51 (both from from Sourcery CodeBench Lite 2014.05) I can > >get a kernel booting on latest master branch. AFAICT, none of the > >LZ4_decompress_* functions are called during boot. > > > >However, using a self-built GCC 7.0 (20161127) and binutils 2.27 I can > >reproduce the problem you see using the instructions Guenter provided in > >the reply to Sven. > > > >I'll try to dig a bit deeper from here on. Any suggestions on what to > >look out for wrt the differences between the gcc/binutils version are > >welcome of course. > > This message doesn't give me enough context to know what is going on, > especially without seeing the rest of the thread. Generally speaking, > Mentor recommends you use one of our stable releases instead of trying to > roll your own from mainline sources. As an upstream binutils and gcc > maintainer I do try my best to look at bug reports for those components, but > I need a reproducible standalone testcase and specific versions of the > different components involved. > The problem is also seen with Sourcery CodeBench Lite 2016.11-32 (gcc 6.2.0, binutils 2.26.51). I can provide additional details if needed, but we don't have a well enough understanding of the problem to be able to provide a reduced size test case. The test used to reproduce the problem is available at https://github.com/groeck/linux-build-test/tree/master/rootfs/nios2, run on the ToT linux kernel. Guenter