2021-05-26 14:04:22

by Yang Yingliang

Subject: [PATCH -next] lib/test_hmm: check page after calling xa_untag_pointer()

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 <[email protected]>
Signed-off-by: Yang Yingliang <[email protected]>
---
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

2021-05-26 20:47:11

by Ralph Campbell

Subject: Re: [PATCH -next] lib/test_hmm: check page after calling xa_untag_pointer()

On 5/26/21 7:05 AM, Yang Yingliang wrote:

> 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 <[email protected]>
> Signed-off-by: Yang Yingliang <[email protected]>
Reviewed-by: Ralph Campbell <[email protected]>