userfaultfd-fix-pte-unmapping-stack-allocated-pte-copies.patch removed from -mm tree

The quilt patch titled
Subject: userfaultfd: fix PTE unmapping stack-allocated PTE copies
has been removed from the -mm tree. Its filename was
userfaultfd-fix-pte-unmapping-stack-allocated-pte-copies.patch

This patch was dropped because it was merged into the mm-hotfixes-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

------------------------------------------------------
From: Suren Baghdasaryan <[email protected]>
Subject: userfaultfd: fix PTE unmapping stack-allocated PTE copies
Date: Wed, 26 Feb 2025 10:55:09 -0800

Current implementation of move_pages_pte() copies source and destination PTEs in order to detect concurrent changes to PTEs involved in the move. However these copies are also used to unmap the PTEs, which will fail if CONFIG_HIGHPTE is enabled because the copies are allocated on the stack. Fix this by using the actual PTEs which were kmap()ed.

---

 mm/userfaultfd.c |   20 ++++++++++----------
 1 file changed, 10 insertions(+), 10 deletions(-)

@@ -1290,8 +1290,8 @@ retry:
 			spin_unlock(src_ptl);
 
 			if (!locked) {
-				pte_unmap(&orig_src_pte);
-				pte_unmap(&orig_dst_pte);
+				pte_unmap(src_pte);
+				pte_unmap(dst_pte);
 				src_pte = dst_pte = NULL;
 				/* now we can block and wait */
 				folio_lock(src_folio);

@@ -1307,8 +1307,8 @@ retry:
 		/* at this point we have src_folio locked */
 		if (folio_test_large(src_folio)) {
 			/* split_folio() can block */
-			pte_unmap(&orig_src_pte);
-			pte_unmap(&orig_dst_pte);
+			pte_unmap(src_pte);
+			pte_unmap(dst_pte);
 			src_pte = dst_pte = NULL;
 			err = split_folio(src_folio);
 			if (err)

@@ -1333,8 +1333,8 @@ retry:
 				goto out;
 			}
 			if (!anon_vma_trylock_write(src_anon_vma)) {
-				pte_unmap(&orig_src_pte);
-				pte_unmap(&orig_dst_pte);
+				pte_unmap(src_pte);
+				pte_unmap(dst_pte);
 				src_pte = dst_pte = NULL;
 				/* now we can block and wait */
 				anon_vma_lock_write(src_anon_vma);

@@ -1352,8 +1352,8 @@ retry:
 		entry = pte_to_swp_entry(orig_src_pte);
 		if (non_swap_entry(entry)) {
 			if (is_migration_entry(entry)) {
-				pte_unmap(&orig_src_pte);
-				pte_unmap(&orig_dst_pte);
+				pte_unmap(src_pte);
+				pte_unmap(dst_pte);
 				src_pte = dst_pte = NULL;
 				migration_entry_wait(mm, src_pmd, src_addr);
 				err = -EAGAIN;

@@ -1396,8 +1396,8 @@ retry:
 			src_folio = folio;
 			src_folio_pte = orig_src_pte;
 			if (!folio_trylock(src_folio)) {
-				pte_unmap(&orig_src_pte);
-				pte_unmap(&orig_dst_pte);
+				pte_unmap(src_pte);
+				pte_unmap(dst_pte);
 				src_pte = dst_pte = NULL;
 				put_swap_device(si);
 				si = NULL;

_

Patches currently in -mm which might be from [email protected] are

mm-avoid-extra-mem_alloc_profiling_enabled-checks.patch alloc_tag-uninline-code-gated-by-mem_alloc_profiling_key-in-slab-allocator.patch alloc_tag-uninline-code-gated-by-mem_alloc_profiling_key-in-page-allocator.patch mm-introduce-vma_start_read_locked_nested-helpers.patch mm-move-per-vma-lock-into-vm_area_struct.patch mm-mark-vma-as-detached-until-its-added-into-vma-tree.patch mm-introduce-vma_iter_store_attached-to-use-with-attached-vmas.patch mm-mark-vmas-detached-upon-exit.patch types-move-struct-rcuwait-into-typesh.patch mm-allow-vma_start_read_locked-vma_start_read_locked_nested-to-fail.patch mm-move-mmap_init_lock-out-of-the-header-file.patch mm-uninline-the-main-body-of-vma_start_write.patch refcount-provide-ops-for-cases-when-objects-memory-can-be-reused.patch refcount-provide-ops-for-cases-when-objects-memory-can-be-reused-fix.patch refcount-introduce-__refcount_addinc_not_zero_limited_acquire.patch mm-replace-vm_lock-and-detached-flag-with-a-reference-count.patch mm-replace-vm_lock-and-detached-flag-with-a-reference-count-fix.patch mm-move-lesser-used-vma_area_struct-members-into-the-last-cacheline.patch mm-debug-print-vm_refcnt-state-when-dumping-the-vma.patch mm-remove-extra-vma_numab_state_init-call.patch mm-prepare-lock_vma_under_rcu-for-vma-reuse-possibility.patch mm-make-vma-cache-slab_typesafe_by_rcu.patch mm-make-vma-cache-slab_typesafe_by_rcu-fix.patch docs-mm-document-latest-changes-to-vm_lock.patch