Re: Incorrect vmcoreinfo KERNELOFFSET after "s390/boot: Rework deployment of the kernel image"

On Wed, Jul 10, 2024 at 07:02:46AM +0200, Petr Tesařík wrote:
...
> > I wasn't able to get real KASLR working on my s390x VM, but what I found
> > in testing without KASLR was:
> > 
> > - Before commit c98d2ecae08f ("s390/mm: Uncouple physical vs virtual
> >   address spaces"), KERNELOFFSET was not set at all (this is expected).
> > - After commit c98d2ecae08f ("s390/mm: Uncouple physical vs virtual
> >   address spaces"), but before commit 56b1069c40c7 ("s390/boot: Rework
> >   deployment of the kernel image"), KERNELOFFSET was set in a way that
> >   drgn understands even without KASLR (that's a little odd but fine with
> >   me).
> > - After commit 56b1069c40c7 ("s390/boot: Rework deployment of the kernel
> >   image"), KERNELOFFSET was set "incorrectly"
> > 
> > So at least for no KASLR, the breakage has been limited only to the 6.10
> > rcs, which isn't too late to fix. I'd be curious what the behavior was
> > with KASLR before 6.10, though.
> 
> OK, I'll check SLES 15 SP5 (kernel 5.14) and SP6 (kernel 6.4). Both
> enable KASLR, but it can be turned off on the command line (or I can
> even rebuild the kernel without CONFIG_RANDOMIZE_BASE if that makes a
> difference).

'nokaslr' kernel option should be enough.

> Petr T

Thanks!