[Buildroot] regression for microblaze architecture

[Buildroot] regression for microblaze architecture

[Waldemar Brodkorb]

Hi,

Buildroot and OpenADK have samples to create a Linux system to be
bootup in Qemu system emulation for microblaze architecture.

With gcc 6.3 and 7.1 the samples are not working anymore, 
because the Linux system userland does not boot.
Qemu 2.9.0:
Kernel panic - not syncing: Attempted to kill init!
exitcode=0x0000000b
(with glibc, musl and uClibc-ng toolchains)

I bisected gcc source code and found the bad commit:
6dcad60c0ef48af584395a40feeb256fb82986a8

When reverting the change, gcc 6.3 and 7.1 produces working
Linux rootfs again.

What can we do about it?

best regards
 Waldemar

[Buildroot] regression for microblaze architecture

[Thomas Petazzoni]

Hello,

On Sat, 27 May 2017 10:51:22 +0200, Waldemar Brodkorb wrote:

> Buildroot and OpenADK have samples to create a Linux system to be
> bootup in Qemu system emulation for microblaze architecture.
> 
> With gcc 6.3 and 7.1 the samples are not working anymore, 
> because the Linux system userland does not boot.
> Qemu 2.9.0:
> Kernel panic - not syncing: Attempted to kill init!
> exitcode=0x0000000b
> (with glibc, musl and uClibc-ng toolchains)
> 
> I bisected gcc source code and found the bad commit:
> 6dcad60c0ef48af584395a40feeb256fb82986a8

Nice, great work!

> When reverting the change, gcc 6.3 and 7.1 produces working
> Linux rootfs again.
> 
> What can we do about it?

 1. Add a revert of this commit in Buildroot for gcc 6.x and 7.x

 2. Report the bug upstream, pointing to the problematic commit

Best regards,

Thomas
-- 
Thomas Petazzoni, CTO, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com