mm: gup: remove useless BUG_ON in __get_user_pages()

Indeed, this BUG_ON couldn't catch anything useful.  We are sure ret == 0
here because we would already bail out if ret != 0 and ret is untouched
till here.

Link: https://lkml.kernel.org/r/20210807093620.21347-4-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/mm/gup.c b/mm/gup.c
index 82074e8..9f5b9a9 100644 (file)
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -1149,7 +1149,6 @@ static long __get_user_pages(struct mm_struct *mm,
                                         * We must stop here.
                                         */
                                        BUG_ON(gup_flags & FOLL_NOWAIT);
-                                       BUG_ON(ret != 0);
                                        goto out;
                                }
                                continue;