Re: [Intel PMC TGPIO Driver 1/5] drivers/ptp: Add Enhanced handling of reserve fields

From: Richard Cochran
Date: Sun Feb 02 2020 - 20:27:16 EST


On Wed, Dec 11, 2019 at 01:48:48PM -0800, christopher.s.hall@xxxxxxxxx wrote:
> diff --git a/drivers/ptp/ptp_chardev.c b/drivers/ptp/ptp_chardev.c
> index 9d72ab593f13..f9ad6df57fa5 100644
> --- a/drivers/ptp/ptp_chardev.c
> +++ b/drivers/ptp/ptp_chardev.c
> @@ -12,6 +12,7 @@
> #include <linux/timekeeping.h>
>
> #include <linux/nospec.h>
> +#include <linux/string.h>

Please group these two includes with the others, above, in
alphabetical order.

> #include "ptp_private.h"
>
> @@ -106,6 +107,28 @@ int ptp_open(struct posix_clock *pc, fmode_t fmode)
> return 0;
> }
>
> +/* Returns -1 if any reserved fields are non-zero */
> +static inline int _check_rsv_field(unsigned int *field, size_t size)

How about _check_reserved_field() instead?

> +{
> + unsigned int *iter;

Ugh, 'ptr' please.

> + int ret = 0;
> +
> + for (iter = field; iter < field+size && ret == 0; ++iter)
> + ret = *iter == 0 ? 0 : -1;

Please use the "early out" pattern:

for (ptr = field; ptr < field + size; ptr++) {
if (*ptr) {
return -1;
}
}
return 0;

Note: field + size
Note: ptr++

> +
> + return ret;
> +}
> +#define check_rsv_field(field) _check_rsv_field(field, ARRAY_SIZE(field))

And check_reserved_field() here. No need to abbreviate.

Thanks,
Richard