On 27/05/2020 16:15, Jan Beulich wrote:

On 21.05.2020 17:23, Steven Price wrote:

quoted

By switching the x86 page table dump code to use the generic code the
effective permissions are no longer calculated correctly because the
note_page() function is only called for *leaf* entries. To calculate the
actual effective permissions it is necessary to observe the full
hierarchy of the page tree.

Introduce a new callback for ptdump which is called for every entry and
can therefore update the prot_levels array correctly. note_page() can
then simply access the appropriate element in the array.

Reported-by: Jan Beulich <redacted>
Fixes: 2ae27137b2db ("x86: mm: convert dump_pagetables to use walk_page_range")
Signed-off-by: Steven Price <steven.price@arm.com>

This (with the later correction) and the 2nd patch
Tested-by: Jan Beulich <redacted>

It allowed me to go and finally find why under Xen there was still
a single W+X mapping left - another bug, another patch.

Thanks, Jan

Thanks for testing (and sorry for breaking it in the first place)!

Steve