From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752455AbdB1QCW (ORCPT ); Tue, 28 Feb 2017 11:02:22 -0500 Received: from sym2.noone.org ([178.63.92.236]:49537 "EHLO sym2.noone.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751497AbdB1QCT (ORCPT ); Tue, 28 Feb 2017 11:02:19 -0500 Date: Tue, 28 Feb 2017 16:53:31 +0100 From: Tobias Klauser To: Guenter Roeck Cc: Sven Schmidt <4sschmid@informatik.uni-hamburg.de>, Arnd Bergmann , Andrew Morton , linux-kernel@vger.kernel.org, Ley Foon Tan , nios2-dev@lists.rocketboards.org, Sandra Loosemore Subject: Re: nios2 crash/hang in mainline due to 'lib: update LZ4 compressor module' Message-ID: <20170228155331.GC27998@distanz.ch> References: <20170226210338.GA19476@roeck-us.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170226210338.GA19476@roeck-us.net> X-Editor: Vi IMproved 7.3 User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org (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. Thanks Tobias