[PATCH] selftests/futex: Fix storing address of local variable

[PATCH] selftests/futex: Fix storing address of local variable

[Ankit Khushwaha]

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In `child_circular_list()` address of local variable ‘struct lock_struct a’
is assigned to `head.list.next` raising the following warning.

robust_list.c: In function ‘child_circular_list’:
robust_list.c:522:24: warning: storing the address of local variable ‘a’
in ‘head.list.next’ [-Wdangling-pointer=]

  522 |         head.list.next = &a.list;
      |         ~~~~~~~~~~~~~~~^~~~~~~~~
robust_list.c:513:28: note: ‘a’ declared here
  513 |         struct lock_struct a, b, c;
      |                            ^
robust_list.c:512:40: note: ‘head’ declared here
  512 |         static struct robust_list_head head;
      |                                        ^~~~

Defining the value with static keyword to fix this.

Signed-off-by: Ankit Khushwaha <ankitkhushwaha.linux@gmail.com>
---
 tools/testing/selftests/futex/functional/robust_list.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/testing/selftests/futex/functional/robust_list.c b/tools/testing/selftests/futex/functional/robust_list.c
index e7d1254e18ca..d1aab1cc5a37 100644
--- a/tools/testing/selftests/futex/functional/robust_list.c
+++ b/tools/testing/selftests/futex/functional/robust_list.c
@@ -510,7 +510,7 @@ TEST(test_robust_list_multiple_elements)
 static int child_circular_list(void *arg)
 {
 	static struct robust_list_head head;
-	struct lock_struct a, b, c;
+	static struct lock_struct a, b, c;
 	int ret;

 	ret = set_list(&head);
--
2.51.1

Re: [PATCH] selftests/futex: Fix storing address of local variable

[André Almeida]

Em 18/11/2025 13:26, Ankit Khushwaha escreveu:
> In `child_circular_list()` address of local variable ‘struct lock_struct a’
> is assigned to `head.list.next` raising the following warning.
> 
> robust_list.c: In function ‘child_circular_list’:
> robust_list.c:522:24: warning: storing the address of local variable ‘a’
> in ‘head.list.next’ [-Wdangling-pointer=]
> 
>    522 |         head.list.next = &a.list;
>        |         ~~~~~~~~~~~~~~~^~~~~~~~~
> robust_list.c:513:28: note: ‘a’ declared here
>    513 |         struct lock_struct a, b, c;
>        |                            ^
> robust_list.c:512:40: note: ‘head’ declared here
>    512 |         static struct robust_list_head head;
>        |                                        ^~~~
> 
> Defining the value with static keyword to fix this.
> 
> Signed-off-by: Ankit Khushwaha <ankitkhushwaha.linux@gmail.com>
> ---
>   tools/testing/selftests/futex/functional/robust_list.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/tools/testing/selftests/futex/functional/robust_list.c b/tools/testing/selftests/futex/functional/robust_list.c
> index e7d1254e18ca..d1aab1cc5a37 100644
> --- a/tools/testing/selftests/futex/functional/robust_list.c
> +++ b/tools/testing/selftests/futex/functional/robust_list.c
> @@ -510,7 +510,7 @@ TEST(test_robust_list_multiple_elements)
>   static int child_circular_list(void *arg)
>   {
>   	static struct robust_list_head head;
> -	struct lock_struct a, b, c;
> +	static struct lock_struct a, b, c;

I believe that the right fix here would be to drop the static from 
`head` declaration, WDYT?

Re: [PATCH] selftests/futex: Fix storing address of local variable

[Ankit Khushwaha]

On Tue, Nov 18, 2025 at 01:34:59PM -0300, André Almeida wrote:
> > diff --git a/tools/testing/selftests/futex/functional/robust_list.c b/tools/testing/selftests/futex/functional/robust_list.c
> > index e7d1254e18ca..d1aab1cc5a37 100644
> > --- a/tools/testing/selftests/futex/functional/robust_list.c
> > +++ b/tools/testing/selftests/futex/functional/robust_list.c
> > @@ -510,7 +510,7 @@ TEST(test_robust_list_multiple_elements)
> >   static int child_circular_list(void *arg)
> >   {
> >   	static struct robust_list_head head;
> > -	struct lock_struct a, b, c;
> > +	static struct lock_struct a, b, c;
> 
> I believe that the right fix here would be to drop the static from `head`
> declaration, WDYT?

Hi André,
I have tested your suggested changes.
It works fine. will send v2 patch for this.

Thanks,
-- Ankit