On 2017-03-01 at 23:50:03 +0100, Sandra Loosemore <san...@codesourcery.com> wrote: > On 03/01/2017 11:58 AM, Sven Schmidt wrote: > >Hi Guenter, Tobias and Sandra, > > > >thanks for your effort here. > > > >On Tue, Feb 28, 2017 at 10:14:13AM -0800, Guenter Roeck wrote: > >>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 <li...@roeck-us.net> 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. > >>>> > > > >It seems a bit strange that code which is not actually called causes > >problems like that. > > > >Please let me know if and how I may help you figure out what's happening, > >especially > >regarding the differences between the previous LZ4 and the current > >implementation. > > > >>>>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. > > Just a suggestion: can you try binutils trunk, too? Alan Modra and > I just tracked down and fixed a bug with the linker creating bad > executables that the kernel's ELF loader couldn't properly map into > memory. IIUC it only affected programs that use dynamic libraries, > but maybe there was more to it than that. In any case it would be > good to know if the problem has already been fixed before > investigating further.
Thanks for the suggestion. Just tried it with a kernel compiled with binutils trunk as of today (2.28.51.20170302) and latest gcc snapshot (7.0.1 20170226). Unfortunately, the issue still persists. Tobias