Merge tag 'mm-stable-2023-05-03-16-22' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull more MM updates from Andrew Morton:

 - Some DAMON cleanups from Kefeng Wang

 - Some KSM work from David Hildenbrand, to make the PR_SET_MEMORY_MERGE
   ioctl's behavior more similar to KSM's behavior.

[ Andrew called these "final", but I suspect we'll have a series fixing
  up the fact that the last commit in the dmapools series in the
  previous pull seems to have unintentionally just reverted all the
  other commits in the same series..   - Linus ]

* tag 'mm-stable-2023-05-03-16-22' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
  mm: hwpoison: coredump: support recovery from dump_user_range()
  mm/page_alloc: add some comments to explain the possible hole in __pageblock_pfn_to_page()
  mm/ksm: move disabling KSM from s390/gmap code to KSM code
  selftests/ksm: ksm_functional_tests: add prctl unmerge test
  mm/ksm: unmerge and clear VM_MERGEABLE when setting PR_SET_MEMORY_MERGE=0
  mm/damon/paddr: fix missing folio_sz update in damon_pa_young()
  mm/damon/paddr: minor refactor of damon_pa_mark_accessed_or_deactivate()
  mm/damon/paddr: minor refactor of damon_pa_pageout()

1 files changed, 15 insertions, 2 deletions

diff --git a/lib/iov_iter.c b/lib/iov_iter.c
index c3dbe994112c..960223ed9199 100644
--- a/lib/iov_iter.c
+++ b/lib/iov_iter.c
@@ -434,6 +434,7 @@ void iov_iter_init(struct iov_iter *i, unsigned int direction,
 	WARN_ON(direction & ~(READ | WRITE));
 	*i = (struct iov_iter) {
 		.iter_type = ITER_IOVEC,
+		.copy_mc = false,
 		.nofault = false,
 		.user_backed = true,
 		.data_source = direction,
@@ -630,6 +631,14 @@ size_t _copy_mc_to_iter(const void *addr, size_t bytes, struct iov_iter *i)
 EXPORT_SYMBOL_GPL(_copy_mc_to_iter);
 #endif /* CONFIG_ARCH_HAS_COPY_MC */
 
+static void *memcpy_from_iter(struct iov_iter *i, void *to, const void *from,
+				 size_t size)
+{
+	if (iov_iter_is_copy_mc(i))
+		return (void *)copy_mc_to_kernel(to, from, size);
+	return memcpy(to, from, size);
+}
+
 size_t _copy_from_iter(void *addr, size_t bytes, struct iov_iter *i)
 {
 	if (WARN_ON_ONCE(!i->data_source))
@@ -639,7 +648,7 @@ size_t _copy_from_iter(void *addr, size_t bytes, struct iov_iter *i)
 		might_fault();
 	iterate_and_advance(i, bytes, base, len, off,
 		copyin(addr + off, base, len),
-		memcpy(addr + off, base, len)
+		memcpy_from_iter(i, addr + off, base, len)
 	)
 
 	return bytes;
@@ -862,7 +871,7 @@ size_t copy_page_from_iter_atomic(struct page *page, unsigned offset, size_t byt
 	}
 	iterate_and_advance(i, bytes, base, len, off,
 		copyin(p + off, base, len),
-		memcpy(p + off, base, len)
+		memcpy_from_iter(i, p + off, base, len)
 	)
 	kunmap_atomic(kaddr);
 	return bytes;
@@ -1043,6 +1052,7 @@ void iov_iter_kvec(struct iov_iter *i, unsigned int direction,
 	WARN_ON(direction & ~(READ | WRITE));
 	*i = (struct iov_iter){
 		.iter_type = ITER_KVEC,
+		.copy_mc = false,
 		.data_source = direction,
 		.kvec = kvec,
 		.nr_segs = nr_segs,
@@ -1059,6 +1069,7 @@ void iov_iter_bvec(struct iov_iter *i, unsigned int direction,
 	WARN_ON(direction & ~(READ | WRITE));
 	*i = (struct iov_iter){
 		.iter_type = ITER_BVEC,
+		.copy_mc = false,
 		.data_source = direction,
 		.bvec = bvec,
 		.nr_segs = nr_segs,
@@ -1105,6 +1116,7 @@ void iov_iter_xarray(struct iov_iter *i, unsigned int direction,
 	BUG_ON(direction & ~1);
 	*i = (struct iov_iter) {
 		.iter_type = ITER_XARRAY,
+		.copy_mc = false,
 		.data_source = direction,
 		.xarray = xarray,
 		.xarray_start = start,
@@ -1128,6 +1140,7 @@ void iov_iter_discard(struct iov_iter *i, unsigned int direction, size_t count)
 	BUG_ON(direction != READ);
 	*i = (struct iov_iter){
 		.iter_type = ITER_DISCARD,
+		.copy_mc = false,
 		.data_source = false,
 		.count = count,
 		.iov_offset = 0