On Wed, Aug 28, 2019 at 07:41:14AM +0000, Eran Ben Elisha wrote:
>
>
> On 8/26/2019 3:56 PM, Dan Carpenter wrote:
> > Hello Eran Ben Elisha,
> >
> > The patch cef35af34d6d: "net/mlx5e: Add mlx5e HV VHCA stats agent"
> > from Aug 22, 2019, leads to the following static checker warning:
> >
> > drivers/net/ethernet/mellanox/mlx5/core/en/hv_vhca_stats.c:41 mlx5e_hv_vhca_fill_stats()
> > warn: potential pointer math issue ('buf' is a u64 pointer)
> >
> > drivers/net/ethernet/mellanox/mlx5/core/en/hv_vhca_stats.c
> > 33 static void mlx5e_hv_vhca_fill_stats(struct mlx5e_priv *priv, u64 *data,
> > ^^^^^^^^^
> > data is a u64 pointer.
> >
> > 34 int buf_len)
> > 35 {
> > 36 int ch, i = 0;
> > 37
> > 38 for (ch = 0; ch < priv->max_nch; ch++) {
> > 39 u64 *buf = data + i;
> > ^^^^^^^^
> >
> > 40
> > 41 if (WARN_ON_ONCE(buf +
> > 42 sizeof(struct mlx5e_hv_vhca_per_ring_stats) >
> > ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> > This pointer math doesn't work. I'm surprised the warning doesn't
> > trigger.
>
> It it not triggered as both 'data' and 'buf' are u64*,
> and sizeof(struct mlx5e_hv_vhca_per_ring_stats) < buf_len as expected.
> This checker does the work, but over wrong range.
Ah. Of course. Thanks!
regards,
dan carpenter
