Check page after calling xa_untag_pointer() to fix compile warning: lib/test_hmm.c:631:16: warning: variable ‘page’ set but not used [-Wunused-but-set-variable] 631 | struct page *page; | ^~~~ Fixes: 8b2a105c3794 ("mm: selftests for exclusive device memory") Reported-by: Hulk Robot <hulkci@xxxxxxxxxx> Signed-off-by: Yang Yingliang <yangyingliang@xxxxxxxxxx> --- lib/test_hmm.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/lib/test_hmm.c b/lib/test_hmm.c index 74d69f87691e..87db37e51d7b 100644 --- a/lib/test_hmm.c +++ b/lib/test_hmm.c @@ -632,7 +632,7 @@ static int dmirror_check_atomic(struct dmirror *dmirror, unsigned long start, entry = xa_load(&dmirror->pt, pfn); page = xa_untag_pointer(entry); - if (xa_pointer_tag(entry) == DPT_XA_TAG_ATOMIC) + if (!page || xa_pointer_tag(entry) == DPT_XA_TAG_ATOMIC) return -EPERM; } -- 2.25.1