Re: [PATCH] tee: optee: Initialize some structs using memset instead of braces

[Sumit Garg]

On Tue, 19 Feb 2019 at 14:45, Nathan Chancellor
<natechancellor@xxxxxxxxx> wrote:
>
> Clang warns:
>
> drivers/tee/optee/device.c:39:31: warning: suggest braces around
> initialization of subobject [-Wmissing-braces]
>         struct tee_param param[4] = {0};
>                                      ^
>                                      {}
> drivers/tee/optee/device.c:92:48: warning: suggest braces around
> initialization of subobject [-Wmissing-braces]
>         struct tee_ioctl_open_session_arg sess_arg = {0};
>                                                       ^
>                                                       {}
> 2 warnings generated.
>
> One way to fix these warnings is to add additional braces like Clang
> suggests; however, there has been a bit of push back from some
> maintainers, who just prefer memset as it is unambiguous, doesn't
> depend on a particular compiler version, and properly initializes all
> subobjects [1][2]. Do that here so there are no more warnings.
>
> [1]: https://lore.kernel.org/lkml/022e41c0-8465-dc7a-a45c-64187ecd9684@xxxxxxx/
> [2]: https://lore.kernel.org/lkml/20181128.215241.702406654469517539.davem@xxxxxxxxxxxxx/
>
> Fixes: c3fa24af9244 ("tee: optee: add TEE bus device enumeration support")
> Link: https://github.com/ClangBuiltLinux/linux/issues/370
> Signed-off-by: Nathan Chancellor <natechancellor@xxxxxxxxx>

Reviewed-by: Sumit Garg <sumit.garg@xxxxxxxxxx>

> ---
>  drivers/tee/optee/device.c | 11 ++++++++---
>  1 file changed, 8 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/tee/optee/device.c b/drivers/tee/optee/device.c
> index 5e4938bbef2b..167839b371f2 100644
> --- a/drivers/tee/optee/device.c
> +++ b/drivers/tee/optee/device.c
> @@ -35,8 +35,11 @@ static int get_devices(struct tee_context *ctx, u32 session,
>                        struct tee_shm *device_shm, u32 *shm_size)
>  {
>         u32 ret = 0;
> -       struct tee_ioctl_invoke_arg inv_arg = {0};
> -       struct tee_param param[4] = {0};
> +       struct tee_ioctl_invoke_arg inv_arg;
> +       struct tee_param param[4];
> +
> +       memset(&inv_arg, 0, sizeof(inv_arg));
> +       memset(&param, 0, sizeof(param));
>
>         /* Invoke PTA_CMD_GET_DEVICES function */
>         inv_arg.func = PTA_CMD_GET_DEVICES;
> @@ -89,13 +92,15 @@ int optee_enumerate_devices(void)
>         const uuid_t pta_uuid =
>                 UUID_INIT(0x7011a688, 0xddde, 0x4053,
>                           0xa5, 0xa9, 0x7b, 0x3c, 0x4d, 0xdf, 0x13, 0xb8);
> -       struct tee_ioctl_open_session_arg sess_arg = {0};
> +       struct tee_ioctl_open_session_arg sess_arg;
>         struct tee_shm *device_shm = NULL;
>         const uuid_t *device_uuid = NULL;
>         struct tee_context *ctx = NULL;
>         u32 shm_size = 0, idx, num_devices = 0;
>         int rc;
>
> +       memset(&sess_arg, 0, sizeof(sess_arg));
> +
>         /* Open context with OP-TEE driver */
>         ctx = tee_client_open_context(NULL, optee_ctx_match, NULL, NULL);
>         if (IS_ERR(ctx))
> --
> 2.21.0.rc1
>