[PATCH] mincore: vma crossing fix

My mincore also forgot about crossing vmas.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/mm/mincore.c b/mm/mincore.c
index 9c1d0a426e95f7b10cd14ee986d9cbe69fcc37f9..5efe0ded69b1857935d0295e9999210e4999a516 100644 (file)
--- a/mm/mincore.c
+++ b/mm/mincore.c
@@ -77,8 +77,16 @@ static long do_mincore(unsigned long addr, unsigned char *vec, unsigned long pag
         * PTE array for our address.
         */
        nr = PTRS_PER_PTE - ((addr >> PAGE_SHIFT) & (PTRS_PER_PTE-1));
-       if (nr > pages)
-               nr = pages;
+
+       /*
+        * Don't overrun this vma
+        */
+       nr = min(nr, (vma->vm_end - addr) >> PAGE_SHIFT);
+
+       /*
+        * Don't return more than the caller asked for
+        */
+       nr = min(nr, pages);
 
        pgd = pgd_offset(vma->vm_mm, addr);
        if (pgd_none_or_clear_bad(pgd))