From: Peter Xu <peterx@xxxxxxxxxx> Subject: mm/pagemap: export uffd-wp protection information Export the PTE/PMD status of uffd-wp to pagemap too. Link: https://lkml.kernel.org/r/20210428225030.9708-6-peterx@xxxxxxxxxx Signed-off-by: Peter Xu <peterx@xxxxxxxxxx> Cc: Alexander Viro <viro@xxxxxxxxxxxxxxxxxx> Cc: Andrea Arcangeli <aarcange@xxxxxxxxxx> Cc: Axel Rasmussen <axelrasmussen@xxxxxxxxxx> Cc: Brian Geffon <bgeffon@xxxxxxxxxx> Cc: "Dr . David Alan Gilbert" <dgilbert@xxxxxxxxxx> Cc: Hugh Dickins <hughd@xxxxxxxxxx> Cc: Jerome Glisse <jglisse@xxxxxxxxxx> Cc: Joe Perches <joe@xxxxxxxxxxx> Cc: Kirill A. Shutemov <kirill@xxxxxxxxxxxxx> Cc: Lokesh Gidra <lokeshgidra@xxxxxxxxxx> Cc: Mike Kravetz <mike.kravetz@xxxxxxxxxx> Cc: Mike Rapoport <rppt@xxxxxxxxxxxxxxxxxx> Cc: Mina Almasry <almasrymina@xxxxxxxxxx> Cc: Oliver Upton <oupton@xxxxxxxxxx> Cc: Shaohua Li <shli@xxxxxx> Cc: Shuah Khan <shuah@xxxxxxxxxx> Cc: Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx> Cc: Wang Qing <wangqing@xxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- Documentation/admin-guide/mm/pagemap.rst | 2 ++ fs/proc/task_mmu.c | 9 +++++++++ 2 files changed, 11 insertions(+) --- a/Documentation/admin-guide/mm/pagemap.rst~mm-pagemap-export-uffd-wp-protection-information +++ a/Documentation/admin-guide/mm/pagemap.rst @@ -21,6 +21,8 @@ There are four components to pagemap: * Bit 55 pte is soft-dirty (see :ref:`Documentation/admin-guide/mm/soft-dirty.rst <soft_dirty>`) * 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 * Bit 61 page is file-page or shared-anon (since 3.5) * Bit 62 page swapped --- a/fs/proc/task_mmu.c~mm-pagemap-export-uffd-wp-protection-information +++ a/fs/proc/task_mmu.c @@ -1302,6 +1302,7 @@ struct pagemapread { #define PM_PFRAME_MASK GENMASK_ULL(PM_PFRAME_BITS - 1, 0) #define PM_SOFT_DIRTY BIT_ULL(55) #define PM_MMAP_EXCLUSIVE BIT_ULL(56) +#define PM_UFFD_WP BIT_ULL(57) #define PM_FILE BIT_ULL(61) #define PM_SWAP BIT_ULL(62) #define PM_PRESENT BIT_ULL(63) @@ -1375,10 +1376,14 @@ static pagemap_entry_t pte_to_pagemap_en page = vm_normal_page(vma, addr, pte); if (pte_soft_dirty(pte)) flags |= PM_SOFT_DIRTY; + if (pte_uffd_wp(pte)) + flags |= PM_UFFD_WP; } else if (is_swap_pte(pte)) { swp_entry_t entry; if (pte_swp_soft_dirty(pte)) flags |= PM_SOFT_DIRTY; + if (pte_swp_uffd_wp(pte)) + flags |= PM_UFFD_WP; entry = pte_to_swp_entry(pte); if (pm->show_pfn) frame = swp_type(entry) | @@ -1426,6 +1431,8 @@ static int pagemap_pmd_range(pmd_t *pmdp flags |= PM_PRESENT; if (pmd_soft_dirty(pmd)) flags |= PM_SOFT_DIRTY; + if (pmd_uffd_wp(pmd)) + flags |= PM_UFFD_WP; if (pm->show_pfn) frame = pmd_pfn(pmd) + ((addr & ~PMD_MASK) >> PAGE_SHIFT); @@ -1444,6 +1451,8 @@ static int pagemap_pmd_range(pmd_t *pmdp flags |= PM_SWAP; if (pmd_swp_soft_dirty(pmd)) flags |= PM_SOFT_DIRTY; + if (pmd_swp_uffd_wp(pmd)) + flags |= PM_UFFD_WP; VM_BUG_ON(!is_pmd_migration_entry(pmd)); page = migration_entry_to_page(entry); } _
