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

[Scott Feldman <scofeldm@cisco.com>]

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;