Re: [PATCH 1/4] drivers/net/enic: decrement sizeof size in strncmp

Scott Feldman
2009-11-16T23:46:24Z

Thanks Julia/Jorg. We'll pick up change in next enic patch series.

-scott

On 11/11/09 11:48 PM, "Julia Lawall" <julia@diku.dk> wrote:

> From: Julia Lawall <julia@diku.dk>
>
> As observed by Joe Perches, sizeof of a constant string includes the
> trailing 0. If what is wanted is to check the initial characters of
> another string, this trailing 0 should not be taken into account. If an
> exact match is wanted, strcmp should be used instead.
>
> The semantic patch that makes this change is as follows:
> (http://coccinelle.lip6.fr/)
>
> // <smpl>
> @@
> expression foo;
> constant char *abc;
> @@
>
> strncmp(foo, abc,
> - sizeof(abc)
> + sizeof(abc)-1
> )
> // </smpl>
>
> Signed-off-by: Julia Lawall <julia@diku.dk>
>
> ---
> drivers/net/enic/vnic_dev.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff -u -p a/drivers/net/enic/vnic_dev.c b/drivers/net/enic/vnic_dev.c
> --- a/drivers/net/enic/vnic_dev.c
> +++ b/drivers/net/enic/vnic_dev.c
> @@ -358,9 +358,9 @@ int vnic_dev_hw_version(struct vnic_dev
> if (err)
> return err;
>
> - if (strncmp(fw_info->hw_version, "A1", sizeof("A1")) == 0)
> + if (strncmp(fw_info->hw_version, "A1", sizeof("A1") - 1) == 0)
> *hw_ver = VNIC_DEV_HW_VER_A1;
> - else if (strncmp(fw_info->hw_version, "A2", sizeof("A2")) == 0)
> + else if (strncmp(fw_info->hw_version, "A2", sizeof("A2") - 1) == 0)
> *hw_ver = VNIC_DEV_HW_VER_A2;
> else
> *hw_ver = VNIC_DEV_HW_VER_UNKNOWN;