Re: Arm64 crash while reading memory sysfs

From: Mike Rapoport
Date: Mon Jun 14 2021 - 04:26:19 EST


On Tue, Jun 08, 2021 at 12:36:21PM +0530, Anshuman Khandual wrote:
>
>
> On 5/28/21 10:43 AM, Mike Rapoport wrote:
> > On Thu, May 27, 2021 at 03:56:44PM -0700, Andrew Morton wrote:
> >> On Thu, 27 May 2021 18:50:48 +0100 Catalin Marinas <catalin.marinas@xxxxxxx> wrote:
> >>
> >>>> Can you please try Anshuman's patch "arm64/mm: Drop HAVE_ARCH_PFN_VALID":
> >>>>
> >>>> https://lore.kernel.org/lkml/1621947349-25421-1-git-send-email-anshuman.khandual@xxxxxxx
> >>>>
> >>>> It seems to me that the check for memblock_is_memory() in
> >>>> arm64::pfn_valid() is what makes init_unavailable_range() to bail out for
> >>>> section parts that are not actually populated and then we have
> >>>> VM_BUG_ON_PAGE(PagePoisoned(p)) for these pages.
> >>>
> >>> I acked Anshuman's patch, I think they all need to go in together.
> >>
> >> That's neat. Specifically which patches are we referring to here?
> >
> > arm64: drop pfn_valid_within() and simplify pfn_valid():
> > https://lore.kernel.org/lkml/20210511100550.28178-5-rppt@xxxxxxxxxx
> >
> > arm64/mm: Drop HAVE_ARCH_PFN_VALID:
> > https://lore.kernel.org/lkml/1621947349-25421-1-git-send-email-anshuman.khandual@xxxxxxx
>
> I dont see the above patch (which drops HAVE_ARCH_PFN_VALID on arm64) on linux-next
> i.e. next-20210607. I might have missed some earlier context here but do not we want
> to fallback on generic pfn_valid() after Mike's series ?

Andrew,

Can you please pick the two patches above?

--
Sincerely yours,
Mike.