[PATCH] mm/madvise: fixup stray mmap lock assert in anon_vma_name()

[Lorenzo Stoakes]

anon_vma_name() is being called under VMA lock, but is assert mmap lock which
won't necessarily be held.

This results in the kernel spamming warnings about this on startup.

Replace this with an open-coded 'mmap or VMA lock' assert to resolve.

Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@xxxxxxxxxx>
---
 mm/madvise.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/mm/madvise.c b/mm/madvise.c
index c467ee42596f..0530d033b3dd 100644
--- a/mm/madvise.c
+++ b/mm/madvise.c
@@ -108,7 +108,8 @@ void anon_vma_name_free(struct kref *kref)

 struct anon_vma_name *anon_vma_name(struct vm_area_struct *vma)
 {
-	mmap_assert_locked(vma->vm_mm);
+	if (!rwsem_is_locked(&vma->vm_mm->mmap_lock))
+		vma_assert_locked(vma);

 	return vma->anon_name;
 }
--
2.50.0