Re: [PATCH v3 2/6] kselftest: factor out list manipulation to a helper

[Kees Cook <keescook@chromium.org>]

On Mon, Mar 16, 2020 at 03:56:42PM -0700, Jakub Kicinski wrote:
> Kees suggest to factor out the list append code to a macro,
> since following commits need it, which leads to code duplication.
> 
> Suggested-by: Kees Cook <keescook@chromium.org>
> Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Acked-by: Kees Cook <keescook@chromium.org>

-Kees

> ---
>  tools/testing/selftests/kselftest_harness.h | 42 ++++++++++++---------
>  1 file changed, 24 insertions(+), 18 deletions(-)
> 
> diff --git a/tools/testing/selftests/kselftest_harness.h b/tools/testing/selftests/kselftest_harness.h
> index 5336b26506ab..aaf58fffc8f7 100644
> --- a/tools/testing/selftests/kselftest_harness.h
> +++ b/tools/testing/selftests/kselftest_harness.h
> @@ -631,6 +631,29 @@
>  	} \
>  } while (0); OPTIONAL_HANDLER(_assert)
>  
> +/* List helpers */
> +#define __LIST_APPEND(head, item) \
> +{ \
> +	/* Circular linked list where only prev is circular. */ \
> +	if (head == NULL) { \
> +		head = item; \
> +		item->next = NULL; \
> +		item->prev = item; \
> +		return;	\
> +	} \
> +	if (__constructor_order == _CONSTRUCTOR_ORDER_FORWARD) { \
> +		item->next = NULL; \
> +		item->prev = head->prev; \
> +		item->prev->next = item; \
> +		head->prev = item; \
> +	} else { \
> +		item->next = head; \
> +		item->next->prev = item; \
> +		item->prev = item; \
> +		head = item; \
> +	} \
> +}
> +
>  /* Contains all the information for test execution and status checking. */
>  struct __test_metadata {
>  	const char *name;
> @@ -665,24 +688,7 @@ static int __constructor_order;
>  static inline void __register_test(struct __test_metadata *t)
>  {
>  	__test_count++;
> -	/* Circular linked list where only prev is circular. */
> -	if (__test_list == NULL) {
> -		__test_list = t;
> -		t->next = NULL;
> -		t->prev = t;
> -		return;
> -	}
> -	if (__constructor_order == _CONSTRUCTOR_ORDER_FORWARD) {
> -		t->next = NULL;
> -		t->prev = __test_list->prev;
> -		t->prev->next = t;
> -		__test_list->prev = t;
> -	} else {
> -		t->next = __test_list;
> -		t->next->prev = t;
> -		t->prev = t;
> -		__test_list = t;
> -	}
> +	__LIST_APPEND(__test_list, t);
>  }
>  
>  static inline int __bail(int for_realz, bool no_print, __u8 step)
> -- 
> 2.24.1
> 

-- 
Kees Cook