Re: [Qemu-devel] [PULL 2/3] s390-ccw.img: Fix sporadic errors with ccw boot image - initialize css

[Cornelia Huck]

On Thu, 13 Feb 2014 10:17:10 +0100
Christian Borntraeger <address@hidden> wrote:

> We have to set the cssid to 0, otherwise the stsch code will
> return an operand exception without the m bit. In the same way
> we should set m=0.
> 
> This case was triggered in some cases during reboot, if for some
> reason the location of blk_schid.cssid contains 1 and m was 0.
> Turns out that the qemu elf loader does not zero out the bss section.
> On first boot this is ok, but on reboots this might fail.
> 
> The symptom was an dump of the old kernel with several areas
> overwritten. The bootloader does not register a program check
> handler, so bios exception jumped back into the old kernel.
> 
> Lets just use a local struct with a designed initializer. That
> will guarantee that all other subelements are initialized to 0.
> 
> Signed-off-by: Christian Borntraeger <address@hidden>
> ---
>  pc-bios/s390-ccw/main.c | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)

Reviewed-by: Cornelia Huck <address@hidden>