+ mm-mremap-use-helper-mlock_future_check.patch added to -mm tree

+ mm-mremap-use-helper-mlock_future_check.patch added to -mm tree

[Andrew Morton]

The patch titled
     Subject: mm/mremap: use helper mlock_future_check()
has been added to the -mm tree.  Its filename is
     mm-mremap-use-helper-mlock_future_check.patch

This patch should soon appear at
    https://ozlabs.org/~akpm/mmots/broken-out/mm-mremap-use-helper-mlock_future_check.patch
and later at
    https://ozlabs.org/~akpm/mmotm/broken-out/mm-mremap-use-helper-mlock_future_check.patch

Before you just go and hit "reply", please:
   a) Consider who else should be cc'ed
   b) Prefer to cc a suitable mailing list as well
   c) Ideally: find the original patch on the mailing list and do a
      reply-to-all to that, adding suitable additional cc's

*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***

The -mm tree is included into linux-next and is updated
there every 3-4 working days

------------------------------------------------------
From: Miaohe Lin <linmiaohe@huawei.com>
Subject: 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>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/mremap.c |   10 ++--------
 1 file changed, 2 insertions(+), 8 deletions(-)

--- a/mm/mremap.c~mm-mremap-use-helper-mlock_future_check
+++ a/mm/mremap.c
@@ -763,14 +763,8 @@ static struct vm_area_struct *vma_to_res
 	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))
_

Patches currently in -mm which might be from linmiaohe@huawei.com are

mm-mremap-use-helper-mlock_future_check.patch