Hi Sasha,
On 20.04.22 17:49, Sasha Levin wrote:
On Wed, Apr 20, 2022 at 05:43:41AM -0700, Georgi Djakov wrote:
From: Anshuman Khandual <anshuman.khandual@xxxxxxx>
[ Upstream commit 3de360c3fdb34fbdbaf6da3af94367d3fded95d3 ]
CONFIG_SPARSEMEM_VMEMMAP is now the only available memory model on arm64
platforms and free_unused_memmap() would just return without creating any
holes in the memmap mapping. There is no need for any special handling in
pfn_valid() and HAVE_ARCH_PFN_VALID can just be dropped. This also moves
the pfn upper bits sanity check into generic pfn_valid().
It's not clear why we need this patch in stable.
I added a Link: tag, pointing to the discussion where the problem is explained
in details and the suggestion to backport these patches to 5.15. But probably
this is not enough and i should have mentioned it in the commit message too.
So in short:
This is fixing a crash on systems where the RAM base address is not aligned
to the pageblock size. Only v5.15 is affected.
> Fixes: 859a85ddf90e ("mm: remove pfn_valid_within() and CONFIG_HOLES_IN_ZONE")
> Link: https://lore.kernel.org/r/Yl0IZWT2nsiYtqBT@xxxxxxxxxxxxx
Thanks,
Georgi
