Re: [Qemu-devel] 'tcg fatal error' with qemu v2.6.0-rc3 (bisected)

[Aurelien Jarno <aurelien@aurel32.net>]

On 2016-04-26 20:12, Guenter Roeck wrote:
> Hi,
> 
> when running qemu version 2.6.0-rc3, I get the following error message.
> 
> /opt/buildbot/qemu/qemu/tcg/tcg.c:1769: tcg fatal error
> 
> qemu command line is as follows.
> 
> qemu-system-ppc64 -M mpc8544ds \
> 	-cpu e5500 \
> 	-m 1024 -kernel arch/powerpc/boot/uImage -initrd busybox-ppc.cpio \
> 	-nographic -vga none -monitor null -no-reboot \
> 	--append "rdinit=/sbin/init console=tty console=ttyS0" \
> 	-machine "dt_compatible=fsl,,P5020DS"
> 
> Files are from my test suite at https://github.com/groeck/linux-build-test.

I have try to reproduce the issue with a kernel build with my toolchain
and your defconfig, but it worked for me. Could you please share the
binaries so that it is easier to reproduce the issue?

> Bisect points to commit 40ae5c62ebaaf7d9d3b93b88c2d32bf6342f7889 ("tcg:
> Introduce temp_load"). Bisect log is attached.

I look at this patch again quickly, and I don't think the bug is
actually introduced by this commit, it is just that it does more strict
tests on the value. I guess it was working before by chance by loading
a random value into the register. That said to look deeper into it, it
would be better to be able to reproduce the issue.

Aurelien

-- 
Aurelien Jarno                          GPG: 4096R/1DDD8C9B
aurelien@aurel32.net                 http://www.aurel32.net