Re: [PATCH v2 06/10] selftests/kdbus: fix precedence issues in macros

[David Herrmann]

Hi

On Tue, Jun 9, 2015 at 11:00 PM, Sergei Zviagintsev <sergei@xxxxxxxx> wrote:
> `item' argument in KDBUS_ITEM_NEXT macro is not enclosed into
> parentheses when the cast operator is applied, which leads to improper
> type conversion if `item' is supplied as a complex expression, e.g.
>
>     KDBUS_ITEM_NEXT(condition ? a : b)
>
> RUN_CLONE_CHILD macro has similar issue, missing parentheses around
> `clone_ret' when using indirection operator.
>
> Use parentheses properly to guarantee right precedence.
>
> Signed-off-by: Sergei Zviagintsev <sergei@xxxxxxxx>
> ---
>  tools/testing/selftests/kdbus/kdbus-util.h | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)

Reviewed-by: David Herrmann <dh.herrmann@xxxxxxxxx>

Thanks
David

> diff --git a/tools/testing/selftests/kdbus/kdbus-util.h b/tools/testing/selftests/kdbus/kdbus-util.h
> index b53b03f0565c..df5721ee8f54 100644
> --- a/tools/testing/selftests/kdbus/kdbus-util.h
> +++ b/tools/testing/selftests/kdbus/kdbus-util.h
> @@ -27,7 +27,7 @@
>  #define KDBUS_ITEM_SIZE(s) KDBUS_ALIGN8((s) + KDBUS_ITEM_HEADER_SIZE)
>
>  #define KDBUS_ITEM_NEXT(item) \
> -       (typeof(item))(((uint8_t *)item) + KDBUS_ALIGN8((item)->size))
> +       (typeof(item))((uint8_t *)(item) + KDBUS_ALIGN8((item)->size))
>  #define KDBUS_ITEM_FOREACH(item, head, first)                          \
>         for (item = (head)->first;                                      \
>              ((uint8_t *)(item) < (uint8_t *)(head) + (head)->size) &&  \
> @@ -104,7 +104,7 @@ extern int kdbus_util_verbose;
>         _setup_;                                                        \
>         efd = eventfd(0, EFD_CLOEXEC);                                  \
>         ASSERT_RETURN(efd >= 0);                                        \
> -       *clone_ret = 0;                                                 \
> +       *(clone_ret) = 0;                                               \
>         pid = syscall(__NR_clone, flags, NULL);                         \
>         if (pid == 0) {                                                 \
>                 eventfd_t event_status = 0;                             \
> @@ -129,7 +129,7 @@ extern int kdbus_util_verbose;
>                 ret = TEST_OK;                                          \
>         } else {                                                        \
>                 ret = -errno;                                           \
> -               *clone_ret = -errno;                                    \
> +               *(clone_ret) = -errno;                                  \
>         }                                                               \
>         close(efd);                                                     \
>         ret;                                                            \
> --
> 1.8.3.1
>
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