Re: [GIT PULL] s390 fixes for 6.17-rc3

[Heiko Carstens <hca@linux.ibm.com>]

On Thu, Oct 02, 2025 at 01:05:26PM +0200, Heiko Carstens wrote:
> On Thu, Oct 02, 2025 at 12:44:41AM +0200, Thomas Weißschuh wrote:
> > Hi Alexander, Vasily and Heiko,
> > [    2.118473] Run /init as init process
> > [    2.142148] User process fault: interruption code 0006 ilc:0
> > [    2.142626] CPU: 0 UID: 0 PID: 1 Comm: init Not tainted 6.17.0-rc2-00002-gfcc43a7e294f #24 NONE
> > [    2.142739] Hardware name: QEMU 8561 QEMU (KVM/Linux)
> > [    2.142822] User PSW : 0705200080000000 00000000804087b2
                                                       ^
> > [    2.142911]            R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:1 AS:0 CC:2 PM:0 RI:0 EA:1
> > [    2.142979] User GPRS: 0000000000000000 000000000040c060 ffffffffffffffff 0000000000000002
> > [    2.143022]            0000000000000800 00000000000007ff 0000000000000000 0000000000000000
> > [    2.143061]            0000000000000000 000003ff00000001 000000000040c000 000000007ff720ac
> > [    2.143106]            000000007ff720a4 0000000000409540 00000000804087b2 000000007ff71ec0
> > [    2.143406] User Code: Bad PSW.
> > [    2.144705] Kernel panic - not syncing: Attempted to kill init! exitcode=0x00000004

...

> Hm, this looks like a qemu bug to me.
> 
> Ilya, could you have a look at this please?
> 
> The above report is a specification exception with an instruction length
> code of zero, while the PSW points to a 31 bit user space address. As far
> as I understand the architecture this is only possible for an early PSW
> specification exception (aka invalid PSW); however the PSW looks good to
> me.

I was wrong, the above bit should be zero otherwise it is indeed an early
PSW specification exception. I'll figure out where this comes from, but
might take a few days due to public holiday.