mm/uffd: sanity check write bit for uffd-wp protected ptes

Browse source

Let's add one sanity check for CONFIG_DEBUG_VM on the write bit in
whatever chance we have when walking through the pgtables.  It can bring
the error earlier even before the app notices the data was corrupted on
the snapshot.  Also it helps us to identify this is a wrong pgtable setup,
so hopefully a great information to have for debugging too.

Link: https://lkml.kernel.org/r/20221114000447.1681003-3-peterx@redhat.com
Signed-off-by: Peter Xu <peterx@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Nadav Amit <nadav.amit@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

...

This commit is contained in:

Peter Xu 2022-11-13 19:04:47 -05:00 • committed by Andrew Morton

parent 25e9fa22fb

commit c2da319c2e

1 changed files with 17 additions and 1 deletions

Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL

Download patch file Download diff file Expand all files Collapse all files

18

arch/x86/include/asm/pgtable.h

View file