Merge branch 'akpm' (patches from Andrew)

Merge misc updates from Andrew Morton:
 "146 patches.

  Subsystems affected by this patch series: kthread, ia64, scripts,
  ntfs, squashfs, ocfs2, vfs, and mm (slab-generic, slab, kmemleak,
  dax, kasan, debug, pagecache, gup, shmem, frontswap, memremap,
  memcg, selftests, pagemap, dma, vmalloc, memory-failure, hugetlb,
  userfaultfd, vmscan, mempolicy, oom-kill, hugetlbfs, migration, thp,
  ksm, page-poison, percpu, rmap, zswap, zram, cleanups, hmm, and
  damon)"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (146 commits)
  mm/damon: hide kernel pointer from tracepoint event
  mm/damon/vaddr: hide kernel pointer from damon_va_three_regions() failure log
  mm/damon/vaddr: use pr_debug() for damon_va_three_regions() failure logging
  mm/damon/dbgfs: remove an unnecessary variable
  mm/damon: move the implementation of damon_insert_region to damon.h
  mm/damon: add access checking for hugetlb pages
  Docs/admin-guide/mm/damon/usage: update for schemes statistics
  mm/damon/dbgfs: support all DAMOS stats
  Docs/admin-guide/mm/damon/reclaim: document statistics parameters
  mm/damon/reclaim: provide reclamation statistics
  mm/damon/schemes: account how many times quota limit has exceeded
  mm/damon/schemes: account scheme actions that successfully applied
  mm/damon: remove a mistakenly added comment for a future feature
  Docs/admin-guide/mm/damon/usage: update for kdamond_pid and (mk|rm)_contexts
  Docs/admin-guide/mm/damon/usage: mention tracepoint at the beginning
  Docs/admin-guide/mm/damon/usage: remove redundant information
  Docs/admin-guide/mm/damon/usage: update for scheme quotas and watermarks
  mm/damon: convert macro functions to static inline functions
  mm/damon: modify damon_rand() macro to static inline function
  mm/damon: move damon_rand() definition into damon.h
  ...

1 files changed, 19 insertions, 12 deletions

diff --git a/mm/gup.c b/mm/gup.c
index 2c51e9748a6a..f0af462ac1e2 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -642,12 +642,17 @@ static struct page *follow_pmd_mask(struct vm_area_struct *vma,
 	}
 retry:
 	if (!pmd_present(pmdval)) {
+		/*
+		 * Should never reach here, if thp migration is not supported;
+		 * Otherwise, it must be a thp migration entry.
+		 */
+		VM_BUG_ON(!thp_migration_supported() ||
+				  !is_pmd_migration_entry(pmdval));
+
 		if (likely(!(flags & FOLL_MIGRATION)))
 			return no_page_table(vma, flags);
-		VM_BUG_ON(thp_migration_supported() &&
-				  !is_pmd_migration_entry(pmdval));
-		if (is_pmd_migration_entry(pmdval))
-			pmd_migration_entry_wait(mm, pmd);
+
+		pmd_migration_entry_wait(mm, pmd);
 		pmdval = READ_ONCE(*pmd);
 		/*
 		 * MADV_DONTNEED may convert the pmd to null because
@@ -1672,21 +1677,22 @@ size_t fault_in_writeable(char __user *uaddr, size_t size)
 
 	if (unlikely(size == 0))
 		return 0;
+	if (!user_write_access_begin(uaddr, size))
+		return size;
 	if (!PAGE_ALIGNED(uaddr)) {
-		if (unlikely(__put_user(0, uaddr) != 0))
-			return size;
+		unsafe_put_user(0, uaddr, out);
 		uaddr = (char __user *)PAGE_ALIGN((unsigned long)uaddr);
 	}
 	end = (char __user *)PAGE_ALIGN((unsigned long)start + size);
 	if (unlikely(end < start))
 		end = NULL;
 	while (uaddr != end) {
-		if (unlikely(__put_user(0, uaddr) != 0))
-			goto out;
+		unsafe_put_user(0, uaddr, out);
 		uaddr += PAGE_SIZE;
 	}
 
 out:
+	user_write_access_end();
 	if (size > uaddr - start)
 		return size - (uaddr - start);
 	return 0;
@@ -1771,21 +1777,22 @@ size_t fault_in_readable(const char __user *uaddr, size_t size)
 
 	if (unlikely(size == 0))
 		return 0;
+	if (!user_read_access_begin(uaddr, size))
+		return size;
 	if (!PAGE_ALIGNED(uaddr)) {
-		if (unlikely(__get_user(c, uaddr) != 0))
-			return size;
+		unsafe_get_user(c, uaddr, out);
 		uaddr = (const char __user *)PAGE_ALIGN((unsigned long)uaddr);
 	}
 	end = (const char __user *)PAGE_ALIGN((unsigned long)start + size);
 	if (unlikely(end < start))
 		end = NULL;
 	while (uaddr != end) {
-		if (unlikely(__get_user(c, uaddr) != 0))
-			goto out;
+		unsafe_get_user(c, uaddr, out);
 		uaddr += PAGE_SIZE;
 	}
 
 out:
+	user_read_access_end();
 	(void)c;
 	if (size > uaddr - start)
 		return size - (uaddr - start);