On 15 Jul 2021, at 21:16, Peter Xu [off-list ref] wrote:

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 | 7 +++++++
1 file changed, 7 insertions(+)

diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index 9c5af77b5290..988e29fa1f00 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c

@@ -1389,6 +1389,8 @@ 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);
+	} else if (pte_swp_uffd_wp_special(pte)) {
+		flags |= PM_UFFD_WP;
	}