[PATCH 1/3] mm: mlock: correct a typo in count_mm_mlocked_page_nr() for caculate VMLOCKED pages

[wei . guo . simon]

From: Simon Guo <wei.guo.simon@xxxxxxxxx>

There is a typo/bug in count_mm_mlocked_page_nr() for "&" which is
mistakenly used with "&&".

Also add more checks and some minor change based on Kirill's previous
comment.

Suggested-by: Kirill A. Shutemov <kirill@xxxxxxxxxxxxx>
Signed-off-by: Simon Guo <wei.guo.simon@xxxxxxxxx>
---
 mm/mlock.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/mm/mlock.c b/mm/mlock.c
index fafbb78..145a425 100644
--- a/mm/mlock.c
+++ b/mm/mlock.c
@@ -641,9 +641,11 @@ static int count_mm_mlocked_page_nr(struct mm_struct *mm,
 		vma = mm->mmap;
 
 	for (; vma ; vma = vma->vm_next) {
+		if (start >= vma->vm_end)
+			continue;
 		if (start + len <=  vma->vm_start)
 			break;
-		if (vma->vm_flags && VM_LOCKED) {
+		if (vma->vm_flags & VM_LOCKED) {
 			if (start > vma->vm_start)
 				count -= (start - vma->vm_start);
 			if (start + len < vma->vm_end) {
@@ -654,7 +656,7 @@ static int count_mm_mlocked_page_nr(struct mm_struct *mm,
 		}
 	}
 
-	return (PAGE_ALIGN(count) >> PAGE_SHIFT);
+	return count >> PAGE_SHIFT;
 }
 
 static __must_check int do_mlock(unsigned long start, size_t len, vm_flags_t flags)
-- 
1.8.3.1