From: Yun Zhou <yun.zhou@xxxxxxxxxxxxx> Subject: proc: fix documentation and description of pagemap Since bit 57 was exported for uffd-wp write-protected(commit fb8e37f35a2f), fixing it can reduce some unnecessary confusion. Link: https://lkml.kernel.org/r/20220301044538.3042713-1-yun.zhou@xxxxxxxxxxxxx Fixes: fb8e37f35a2fe1 ("mm/pagemap: export uffd-wp protection information") Signed-off-by: Yun Zhou <yun.zhou@xxxxxxxxxxxxx> Reviewed-by: Peter Xu <peterx@xxxxxxxxxx> Cc: Jonathan Corbet <corbet@xxxxxxx> Cc: Tiberiu A Georgescu <tiberiu.georgescu@xxxxxxxxxxx> Cc: Florian Schmidt <florian.schmidt@xxxxxxxxxxx> Cc: Ivan Teterevkov <ivan.teterevkov@xxxxxxxxxxx> Cc: SeongJae Park <sj@xxxxxxxxxx> Cc: Yang Shi <shy828301@xxxxxxxxx> Cc: David Hildenbrand <david@xxxxxxxxxx> Cc: Axel Rasmussen <axelrasmussen@xxxxxxxxxx> Cc: Miaohe Lin <linmiaohe@xxxxxxxxxx> Cc: Andrea Arcangeli <aarcange@xxxxxxxxxx> Cc: Colin Cross <ccross@xxxxxxxxxx> Cc: Alistair Popple <apopple@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- Documentation/admin-guide/mm/pagemap.rst | 2 +- fs/proc/task_mmu.c | 3 ++- 2 files changed, 3 insertions(+), 2 deletions(-) --- a/Documentation/admin-guide/mm/pagemap.rst~proc-fix-documentation-and-description-of-pagemap +++ a/Documentation/admin-guide/mm/pagemap.rst @@ -23,7 +23,7 @@ There are four components to pagemap: * Bit 56 page exclusively mapped (since 4.2) * Bit 57 pte is uffd-wp write-protected (since 5.13) (see :ref:`Documentation/admin-guide/mm/userfaultfd.rst <userfaultfd>`) - * Bits 57-60 zero + * Bits 58-60 zero * Bit 61 page is file-page or shared-anon (since 3.5) * Bit 62 page swapped * Bit 63 page present --- a/fs/proc/task_mmu.c~proc-fix-documentation-and-description-of-pagemap +++ a/fs/proc/task_mmu.c @@ -1597,7 +1597,8 @@ static const struct mm_walk_ops pagemap_ * Bits 5-54 swap offset if swapped * Bit 55 pte is soft-dirty (see Documentation/admin-guide/mm/soft-dirty.rst) * Bit 56 page exclusively mapped - * Bits 57-60 zero + * Bit 57 pte is uffd-wp write-protected + * Bits 58-60 zero * Bit 61 page is file-page or shared-anon * Bit 62 page swapped * Bit 63 page present _
