On 8/26/2016 12:49 AM, Christophe JAILLET wrote: > The 2nd parameter of 'find_first_bit' is the number of bits to search. > In this case, we are passing 'sizeof(unsigned long)' which is likely to > be 4 or 8.
If the size can be 4 or 8, then using 64 universally is not correct.
Why not use sizeof() * 8 (or << 3)?
> It is likely that the number of bits of 'port_mask' was expected here. This
> variable is a 'u64', so use 64 instead.
>
> It has been spotted by the following coccinelle script:
> @@
> expression ret, x;
>
> @@
> * ret = \(find_first_bit \| find_first_zero_bit\) (x, sizeof(...));
>
> Signed-off-by: Christophe JAILLET <christophe.jail...@wanadoo.fr>
> ---
> Not sure that using 64 directly is the best option.
> Maybe '8 * sizeof(port_mask)' as used in the same file for
> 'for_each_set_bit' would be better
> ---
> drivers/infiniband/hw/hfi1/mad.c | 12 ++++--------
> 1 file changed, 4 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/infiniband/hw/hfi1/mad.c
> b/drivers/infiniband/hw/hfi1/mad.c
> index 1263abe01999..2c6c138c41b2 100644
> --- a/drivers/infiniband/hw/hfi1/mad.c
> +++ b/drivers/infiniband/hw/hfi1/mad.c
> @@ -2632,8 +2632,7 @@ static int pma_get_opa_datacounters(struct opa_pma_mad
> *pmp,
> * port the request came in on.
> */
> port_mask = be64_to_cpu(req->port_select_mask[3]);
> - port_num = find_first_bit((unsigned long *)&port_mask,
> - sizeof(port_mask));
> + port_num = find_first_bit((unsigned long *)&port_mask, 64);
>
> if ((u8)port_num != port) {
> pmp->mad_hdr.status |= IB_SMP_INVALID_FIELD;
> @@ -2836,8 +2835,7 @@ static int pma_get_opa_porterrors(struct opa_pma_mad
> *pmp,
> * port the request came in on.
> */
> port_mask = be64_to_cpu(req->port_select_mask[3]);
> - port_num = find_first_bit((unsigned long *)&port_mask,
> - sizeof(port_mask));
> + port_num = find_first_bit((unsigned long *)&port_mask, 64);
>
> if (port_num != port) {
> pmp->mad_hdr.status |= IB_SMP_INVALID_FIELD;
> @@ -3009,8 +3007,7 @@ static int pma_get_opa_errorinfo(struct opa_pma_mad
> *pmp,
> * the request came in on.
> */
> port_mask = be64_to_cpu(req->port_select_mask[3]);
> - port_num = find_first_bit((unsigned long *)&port_mask,
> - sizeof(port_mask));
> + port_num = find_first_bit((unsigned long *)&port_mask, 64);
>
> if (port_num != port) {
> pmp->mad_hdr.status |= IB_SMP_INVALID_FIELD;
> @@ -3246,8 +3243,7 @@ static int pma_set_opa_errorinfo(struct opa_pma_mad
> *pmp,
> * the request came in on.
> */
> port_mask = be64_to_cpu(req->port_select_mask[3]);
> - port_num = find_first_bit((unsigned long *)&port_mask,
> - sizeof(port_mask));
> + port_num = find_first_bit((unsigned long *)&port_mask, 64);
>
> if (port_num != port) {
> pmp->mad_hdr.status |= IB_SMP_INVALID_FIELD;
>
--
Doug Ledford <dledf...@redhat.com>
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