[merged] mm-mmu_notifier-fix-mmget-assert-in-__mmu_interval_notifier_insert.patch removed from -mm tree

[merged] mm-mmu_notifier-fix-mmget-assert-in-__mmu_interval_notifier_insert.patch removed from -mm tree

[akpm]

The patch titled
     Subject: mm/mmu_notifier: fix mmget() assert in __mmu_interval_notifier_insert
has been removed from the -mm tree.  Its filename was
     mm-mmu_notifier-fix-mmget-assert-in-__mmu_interval_notifier_insert.patch

This patch was dropped because it was merged into mainline or a subsystem tree

------------------------------------------------------
From: Jann Horn <jannh@google.com>
Subject: mm/mmu_notifier: fix mmget() assert in __mmu_interval_notifier_insert

The comment talks about having to hold mmget() (which means mm_users), but
the actual check is on mm_count (which would be mmgrab()).

Given that MMU notifiers are torn down in mmput() -> __mmput() ->
exit_mmap() -> mmu_notifier_release(), I believe that the comment is
correct and the check should be on mm->mm_users.  Fix it up accordingly.

Link: https://lkml.kernel.org/r/20200901000143.207585-1-jannh@google.com
Fixes: 99cb252f5e68 ("mm/mmu_notifier: add an interval tree notifier")
Signed-off-by: Jann Horn <jannh@google.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Christian König <christian.koenig@amd.com
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/mmu_notifier.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/mm/mmu_notifier.c~mm-mmu_notifier-fix-mmget-assert-in-__mmu_interval_notifier_insert
+++ a/mm/mmu_notifier.c
@@ -913,7 +913,7 @@ static int __mmu_interval_notifier_inser
 		return -EOVERFLOW;
 
 	/* Must call with a mmget() held */
-	if (WARN_ON(atomic_read(&mm->mm_count) <= 0))
+	if (WARN_ON(atomic_read(&mm->mm_users) <= 0))
 		return -EINVAL;
 
 	/* pairs with mmdrop in mmu_interval_notifier_remove() */
_

Patches currently in -mm which might be from jannh@google.com are

mm-gup_benchmark-take-the-mmap-lock-around-gup.patch
binfmt_elf-take-the-mmap-lock-around-find_extend_vma.patch
mmap-locking-api-dont-check-locking-if-the-mm-isnt-live-yet.patch
mm-gup-assert-that-the-mmap-lock-is-held-in-__get_user_pages.patch