1 files changed, 14 insertions, 10 deletions

diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index 3f78ebbb7..8433f076e 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -1818,15 +1818,13 @@ static unsigned long pagemap_page_category(struct pagemap_scan_private *p,
 }
 
 static void make_uffd_wp_pte(struct vm_area_struct *vma,
-			     unsigned long addr, pte_t *pte)
+			     unsigned long addr, pte_t *pte, pte_t ptent)
 {
-	pte_t ptent = ptep_get(pte);
-
 	if (pte_present(ptent)) {
 		pte_t old_pte;
 
 		old_pte = ptep_modify_prot_start(vma, addr, pte);
-		ptent = pte_mkuffd_wp(ptent);
+		ptent = pte_mkuffd_wp(old_pte);
 		ptep_modify_prot_commit(vma, addr, pte, old_pte, ptent);
 	} else if (is_swap_pte(ptent)) {
 		ptent = pte_swp_mkuffd_wp(ptent);
@@ -2176,9 +2174,12 @@ static int pagemap_scan_pmd_entry(pmd_t *pmd, unsigned long start,
 	if ((p->arg.flags & PM_SCAN_WP_MATCHING) && !p->vec_out) {
 		/* Fast path for performing exclusive WP */
 		for (addr = start; addr != end; pte++, addr += PAGE_SIZE) {
-			if (pte_uffd_wp(ptep_get(pte)))
+			pte_t ptent = ptep_get(pte);
+
+			if ((pte_present(ptent) && pte_uffd_wp(ptent)) ||
+			    pte_swp_uffd_wp_any(ptent))
 				continue;
-			make_uffd_wp_pte(vma, addr, pte);
+			make_uffd_wp_pte(vma, addr, pte, ptent);
 			if (!flush_end)
 				start = addr;
 			flush_end = addr + PAGE_SIZE;
@@ -2191,8 +2192,10 @@ static int pagemap_scan_pmd_entry(pmd_t *pmd, unsigned long start,
 	    p->arg.return_mask == PAGE_IS_WRITTEN) {
 		for (addr = start; addr < end; pte++, addr += PAGE_SIZE) {
 			unsigned long next = addr + PAGE_SIZE;
+			pte_t ptent = ptep_get(pte);
 
-			if (pte_uffd_wp(ptep_get(pte)))
+			if ((pte_present(ptent) && pte_uffd_wp(ptent)) ||
+			    pte_swp_uffd_wp_any(ptent))
 				continue;
 			ret = pagemap_scan_output(p->cur_vma_category | PAGE_IS_WRITTEN,
 						  p, addr, &next);
@@ -2200,7 +2203,7 @@ static int pagemap_scan_pmd_entry(pmd_t *pmd, unsigned long start,
 				break;
 			if (~p->arg.flags & PM_SCAN_WP_MATCHING)
 				continue;
-			make_uffd_wp_pte(vma, addr, pte);
+			make_uffd_wp_pte(vma, addr, pte, ptent);
 			if (!flush_end)
 				start = addr;
 			flush_end = next;
@@ -2209,8 +2212,9 @@ static int pagemap_scan_pmd_entry(pmd_t *pmd, unsigned long start,
 	}
 
 	for (addr = start; addr != end; pte++, addr += PAGE_SIZE) {
+		pte_t ptent = ptep_get(pte);
 		unsigned long categories = p->cur_vma_category |
-					   pagemap_page_category(p, vma, addr, ptep_get(pte));
+					   pagemap_page_category(p, vma, addr, ptent);
 		unsigned long next = addr + PAGE_SIZE;
 
 		if (!pagemap_scan_is_interesting_page(categories, p))
@@ -2225,7 +2229,7 @@ static int pagemap_scan_pmd_entry(pmd_t *pmd, unsigned long start,
 		if (~categories & PAGE_IS_WRITTEN)
 			continue;
 
-		make_uffd_wp_pte(vma, addr, pte);
+		make_uffd_wp_pte(vma, addr, pte, ptent);
 		if (!flush_end)
 			start = addr;
 		flush_end = next;