Re: CONFIG_DEBUG_VIRTUAL breaks boot on x86-32

[Ralph Campbell]

On 3/26/19 6:52 AM, William Kucharski wrote:
> Does this still happen on 5.1-rc2?
>
> Do you have idea as to what max_low_pfn() gets set to on your system at boot time?
>
>  From the screen shot I'm guessing it MIGHT be 0x373fe, but it's hard to know for sure.
>
>
> > On Mar 21, 2019, at 2:22 PM, Meelis Roos <mroos@xxxxxxxx> wrote:
> >
> > I tried to debug another problem and turned on most debug options for memory.
> > The resulting kernel failed to boot.
> >
> > Bisecting the configurations led to CONFIG_DEBUG_VIRTUAL - if I turned it on
> > in addition to some other debug options, the machine crashed with
> >
> > kernel BUG at arch/x86/mm/physaddr.c:79!
> >
> > Screenshot at http://kodu.ut.ee/~mroos/debug_virtual-boot-hang-1.jpg
> >
> > The machine was Athlon XP with VIA KT600 chipset and 2G RAM.
> >
> > --
> > Meelis Roos <mroos@xxxxxxxx>

You might be hitting a bug I found.
Try applying this patch:
https://marc.info/?l=linux-kernel&m=155355953012985&w=2