fs/proc/task_mmu: fix pagemap flags with PMD THP entries on 32bit

commit 3754137 upstream.

Entries (including flags) are u64, even on 32bit.  So right now we are
cutting of the flags on 32bit.  This way, for example the cow selftest
complains about:

  # ./cow
  ...
  Bail Out! read and ioctl return unmatched results for populated: 0 1

Link: https://lkml.kernel.org/r/[email protected]
Fixes: 2c1f057 ("fs/proc/task_mmu: properly detect PM_MMAP_EXCLUSIVE per page of PMD-mapped THPs")
Signed-off-by: David Hildenbrand <[email protected]>
Cc: Oscar Salvador <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

Author: davidhildenbrand

fs/proc/task_mmu.c

@@ -1516,7 +1516,7 @@ static int pagemap_pmd_range(pmd_t *pmdp, unsigned long addr, unsigned long end,
 			flags |= PM_FILE;
 
 		for (; addr != end; addr += PAGE_SIZE, idx++) {
-			unsigned long cur_flags = flags;
+			u64 cur_flags = flags;
 			pagemap_entry_t pme;
 
 			if (page && (flags & PM_PRESENT) &&