mm/mmap.c: use helper mlock_future_check()

Use helper mlock_future_check() to check whether it's safe to enlarge the
locked_vm to simplify the code.  Minor readability improvement.

Link: https://lkml.kernel.org/r/20220402032231.64974-1-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/mm/mmap.c b/mm/mmap.c
index 7873cc3..e326404 100644 (file)
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -2354,15 +2354,8 @@ static int acct_stack_growth(struct vm_area_struct *vma,
                return -ENOMEM;
 
        /* mlock limit tests */
-       if (vma->vm_flags & VM_LOCKED) {
-               unsigned long locked;
-               unsigned long limit;
-               locked = mm->locked_vm + grow;
-               limit = rlimit(RLIMIT_MEMLOCK);
-               limit >>= PAGE_SHIFT;
-               if (locked > limit && !capable(CAP_IPC_LOCK))
-                       return -ENOMEM;
-       }
+       if (mlock_future_check(mm, vma->vm_flags, grow << PAGE_SHIFT))
+               return -ENOMEM;
 
        /* Check to ensure the stack will not grow into a hugetlb-only region */
        new_start = (vma->vm_flags & VM_GROWSUP) ? vma->vm_start :