From dd21bfa425c098b95ca86845f8e7d1ec1ddf6e4a Mon Sep 17 00:00:00 2001 From: Yun Zhou <yun.zhou@windriver.com> Date: Fri, 4 Mar 2022 20:29:07 -0800 Subject: [PATCH] proc: fix documentation and description of pagemap Since bit 57 was exported for uffd-wp write-protected (commit fb8e37f35a2f: "mm/pagemap: export uffd-wp protection information"), fixing it can reduce some unnecessary confusion. Link: https://lkml.kernel.org/r/20220301044538.3042713-1-yun.zhou@windriver.com Fixes: fb8e37f35a2fe1 ("mm/pagemap: export uffd-wp protection information") Signed-off-by: Yun Zhou <yun.zhou@windriver.com> Reviewed-by: Peter Xu <peterx@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Tiberiu A Georgescu <tiberiu.georgescu@nutanix.com> Cc: Florian Schmidt <florian.schmidt@nutanix.com> Cc: Ivan Teterevkov <ivan.teterevkov@nutanix.com> Cc: SeongJae Park <sj@kernel.org> Cc: Yang Shi <shy828301@gmail.com> Cc: David Hildenbrand <david@redhat.com> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Colin Cross <ccross@google.com> Cc: Alistair Popple <apopple@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> --- Documentation/admin-guide/mm/pagemap.rst | 2 +- fs/proc/task_mmu.c | 3 ++- 2 files changed, 3 insertions(+), 2 deletions(-) diff --git a/Documentation/admin-guide/mm/pagemap.rst b/Documentation/admin-guide/mm/pagemap.rst index bfc28704856c..6e2e416af783 100644 --- a/Documentation/admin-guide/mm/pagemap.rst +++ b/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 diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index 2c48b1eaaa9c..f46060eb91b5 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -1597,7 +1597,8 @@ static const struct mm_walk_ops pagemap_ops = { * 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 -- GitLab