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Subject[PATCH v6 20/23] mm/pagemap: Recognize uffd-wp bit for shmem/hugetlbfs
Date
This requires the pagemap code to be able to recognize the newly introduced
swap special pte for uffd-wp, meanwhile the general case for hugetlb that we
recently start to support. It should make pagemap uffd-wp support complete.

Signed-off-by: Peter Xu <peterx@redhat.com>
---
fs/proc/task_mmu.c | 11 +++++++++++
1 file changed, 11 insertions(+)

diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index ad667dbc96f5..5d2f73b2e63d 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -1390,6 +1390,12 @@ static pagemap_entry_t pte_to_pagemap_entry(struct pagemapread *pm,
flags |= PM_SWAP;
if (is_pfn_swap_entry(entry))
page = pfn_swap_entry_to_page(entry);
+ if (is_pte_marker_entry(entry)) {
+ pte_marker marker = pte_marker_get(entry);
+
+ if (marker & PTE_MARKER_UFFD_WP)
+ flags |= PM_UFFD_WP;
+ }
}

if (page && !PageAnon(page))
@@ -1523,10 +1529,15 @@ static int pagemap_hugetlb_range(pte_t *ptep, unsigned long hmask,
if (page_mapcount(page) == 1)
flags |= PM_MMAP_EXCLUSIVE;

+ if (huge_pte_uffd_wp(pte))
+ flags |= PM_UFFD_WP;
+
flags |= PM_PRESENT;
if (pm->show_pfn)
frame = pte_pfn(pte) +
((addr & ~hmask) >> PAGE_SHIFT);
+ } else if (pte_swp_uffd_wp_any(pte)) {
+ flags |= PM_UFFD_WP;
}

for (; addr != end; addr += PAGE_SIZE) {
--
2.32.0
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