Messages in this thread | | | Date | Tue, 28 Feb 2017 10:14:13 -0800 | From | Guenter Roeck <> | Subject | Re: nios2 crash/hang in mainline due to 'lib: update LZ4 compressor module' |
| |
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 <linux@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. > > > >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
| |