From: Miaohe Lin <linmiaohe@huawei.com>
Date: Fri, 29 Apr 2022 06:16:14 +0000 (-0700)
Subject: mm/mremap: use helper mlock_future_check()
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=f433195679a9639a3af5be03bcb9c3d933e3b261;p=linux.git

mm/mremap: use helper mlock_future_check()

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

Link: https://lkml.kernel.org/r/20220322112004.27380-1-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Wei Yang <richard.weiyang@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

diff --git a/mm/mremap.c b/mm/mremap.c
index 303d3290b9386..f2a53d53f1b92 100644
--- a/mm/mremap.c
+++ b/mm/mremap.c
@@ -766,14 +766,8 @@ static struct vm_area_struct *vma_to_resize(unsigned long addr,
 	if (vma->vm_flags & (VM_DONTEXPAND | VM_PFNMAP))
 		return ERR_PTR(-EFAULT);
 
-	if (vma->vm_flags & VM_LOCKED) {
-		unsigned long locked, lock_limit;
-		locked = mm->locked_vm << PAGE_SHIFT;
-		lock_limit = rlimit(RLIMIT_MEMLOCK);
-		locked += new_len - old_len;
-		if (locked > lock_limit && !capable(CAP_IPC_LOCK))
-			return ERR_PTR(-EAGAIN);
-	}
+	if (mlock_future_check(mm, vma->vm_flags, new_len - old_len))
+		return ERR_PTR(-EAGAIN);
 
 	if (!may_expand_vm(mm, vma->vm_flags,
 				(new_len - old_len) >> PAGE_SHIFT))