On Thu, Jun 12, 2025 at 05:36:35PM +0200, David Hildenbrand wrote:
On 12.06.25 17:28, Lorenzo Stoakes wrote:
On Wed, Jun 11, 2025 at 02:06:52PM +0200, David Hildenbrand wrote:
We setup the cache mode but ... don't forward the updated pgprot to insert_pfn_pud().
Only a problem on x86-64 PAT when mapping PFNs using PUDs that require a special cachemode.
Fix it by using the proper pgprot where the cachemode was setup.
Identified by code inspection.
Fixes: 7b806d229ef1 ("mm: remove vmf_insert_pfn_xxx_prot() for huge page-table entries")
Ha! I don't even remember doing that patch... hm did I introduce this -ignoring cache- thing? Sorry! :P
Cc: stable@vger.kernel.org Signed-off-by: David Hildenbrand david@redhat.com
Nice catch!
Reviewed-by: Lorenzo Stoakes lorenzo.stoakes@oracle.com
Thanks! What's your opinion on stable? Really hard to judge the impact ...
I think it makes sense? This is currently incorrect so let's do the right thing and backport.
I think as per Dan it's probably difficult to picture this causing a problem, but on principle I think this is correct, and I don't see any harm in backporting?
-- Cheers,
David / dhildenb