Re: [PATCH for-9.2 00/10] s390: Convert virtio-ccw, cpu to three-phase reset, and followup cleanup

[Nico Boehr]

Quoting Peter Maydell (2024-08-29 17:53:02)
> On Wed, 28 Aug 2024 at 09:13, Nico Boehr <nrb@linux.ibm.com> wrote:
> >
> > Quoting Nico Boehr (2024-08-26 14:08:20)
> > > There was a little hickup without the fixup to patch 2, but after Nina
> > > pushed the fixup, we did not observe any failures related to your
> > > changes in our CI. Thanks!
> >
> > Peter, after a few CI runs, we unfortunately did find some issues with your
> > patch :-(
> >
> > Rebooting a guest in a loop sometimes fails. Michael was able to bisect it
> > to your series.
> >
> > The problem is intermittent. The guest is unable to load its initramfs:
> >
> >   [    0.560674] rootfs image is not initramfs (no cpio magic); looks like 
> > an initrd
> >   [    0.588605] Freeing initrd memory: 95680K
> >   [    0.593143] md: Waiting for all devices to be available before 
> > autodetect
> >   [    0.593144] md: If you don't use raid, use raid=noautodetect
> >   [    0.593145] md: Autodetecting RAID arrays.
> >   [    0.593146] md: autorun ...
> >   [    0.593147] md: ... autorun DONE.
> >   [    0.593156] RAMDISK: gzip image found at block 0
> >   [    0.609110] RAMDISK: incomplete write (29120 != 32768)
> >   [    0.609113] write error
> >
> > ...and then a panic because the kernel doesn't find a rootfs.
> 
> I repro'd *something*, but it wasn't quite this. I got:
> 
> 
> [    4.691853] clk: Disabling unused clocks
> [    4.695419] Freeing unused kernel image (initmem) memory: 6520K
> [    4.695430] Write protected read-only-after-init data: 144k
> [    4.695834] Checked W+X mappings: passed, no unexpected W+X pages found
> [    4.695849] Run /init as init process
> /init: error while loading shared libraries: libgcc_s.so.1: cannot
> open shared object file: No such file or directory
> [    4.697009] Kernel panic - not syncing: Attempted to kill init!
> exitcode=0x00007f00
> [    4.697030] CPU: 0 PID: 1 Comm: init Not tainted 6.8.5-301.fc40.s390x #1
> [    4.697035] Hardware name: IBM 8561 LT1 400 (KVM/Linux)
> [    4.697040] Call Trace:
> [    4.697047]  [<000000007ab6ae36>] dump_stack_lvl+0x66/0x88
> [    4.697081]  [<0000000079e17c2a>] panic+0x312/0x328
> [    4.697096]  [<0000000079e1de84>] do_exit+0x8a4/0xae8
> [    4.697101]  [<0000000079e1e2e0>] do_group_exit+0x40/0xb8
> [    4.697103]  [<0000000079e1e386>] __s390x_sys_exit_group+0x2e/0x30
> [    4.697105]  [<000000007ab9526a>] __do_syscall+0x252/0x2c0
> [    4.697113]  [<000000007aba8840>] system_call+0x70/0x98
> 
> Which I guess could be caused by a different corruption
> of the initramfs ?

I think that is the problem, just a different symptom. I also got this
sometimes (in random libraries all over the place).

And yes, agree, it is a corruption of the initramfs:
[    1.597465] Initramfs unpacking failed: XZ-compressed data is corrupt