Commit 0874bb49 authored Jun 13, 2019 by swkhack Committed by Linus Torvalds Jun 13, 2019

mm/mlock.c: change count_mm_mlocked_page_nr return type

On a 64-bit machine the value of "vma->vm_end - vma->vm_start" may be
negative when using 32 bit ints and the "count >> PAGE_SHIFT"'s result
will be wrong.  So change the local variable and return value to
unsigned long to fix the problem.

Link: http://lkml.kernel.org/r/20190513023701.83056-1-swkhack@gmail.com


Fixes: 0cf2f6f6 ("mm: mlock: check against vma for actual mlock() size")
Signed-off-by: swkhack <swkhack@gmail.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent 7a30df49

mm/mlock.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -636,11 +636,11 @@ static int apply_vma_lock_flags(unsigned long start, size_t len,
		* is also counted.
		* Return value: previously mlocked page counts
		*/
		static int count_mm_mlocked_page_nr(struct mm_struct *mm,
		static unsigned long count_mm_mlocked_page_nr(struct mm_struct *mm,
		unsigned long start, size_t len)
		{
		struct vm_area_struct *vma;
		int count = 0;
		unsigned long count = 0;

		if (mm == NULL)
		mm = current->mm;

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