Re: [patch] infiniband: remove dead code

Dan Carpenter
2010-03-15T15:07:35Z

On Mon, Mar 15, 2010 at 11:18:47AM -0300, Thadeu Lima de Souza Cascardo wrote:
> On Mon, Mar 15, 2010 at 11:23:32AM +0300, Dan Carpenter wrote:
> > "ret" is initialized to -ENOMEM so we don't need to set it here.
> >
> > Signed-off-by: Dan Carpenter <error27@gmail.com>
> >
> > diff --git a/drivers/infiniband/ulp/iser/iser_verbs.c b/drivers/infiniband/ulp/iser/iser_verbs.c
> > index 308d17b..8fa6997 100644
> > --- a/drivers/infiniband/ulp/iser/iser_verbs.c
> > +++ b/drivers/infiniband/ulp/iser/iser_verbs.c
> > @@ -148,10 +148,8 @@ static int iser_create_ib_conn_res(struct iser_conn *ib_conn)
> > device = ib_conn->device;
> >
> > ib_conn->login_buf = kmalloc(ISER_RX_LOGIN_SIZE, GFP_KERNEL);
> > - if (!ib_conn->login_buf) {
> > + if (!ib_conn->login_buf)
> > goto alloc_err;
> > - ret = -ENOMEM;
> > - }
> >
> > ib_conn->login_dma = ib_dma_map_single(ib_conn->device->ib_device,
> > (void *)ib_conn->login_buf, ISER_RX_LOGIN_SIZE,
> > @@ -160,10 +158,9 @@ static int iser_create_ib_conn_res(struct iser_conn *ib_conn)
> > ib_conn->page_vec = kmalloc(sizeof(struct iser_page_vec) +
> > (sizeof(u64) * (ISCSI_ISER_SG_TABLESIZE +1)),
> > GFP_KERNEL);
> > - if (!ib_conn->page_vec) {
> > - ret = -ENOMEM;
> > + if (!ib_conn->page_vec)
> > goto alloc_err;
> > - }
> > +
> > ib_conn->page_vec->pages = (u64 *) (ib_conn->page_vec + 1);
> >
> > params.page_shift = SHIFT_4K;
>
> If there's a failure while allocating page_vec, login_buf will not be
> released. A single extra label should solve this.
>
> Regards,
> Cascardo.

Hm... Actually it looks like we should just remove both those
calls to kfree() and the ib_destroy_fmr_pool(). Otherwise we'll do
a double free when we get to iser_conn_release().

The call tree looks like this:
iser_connect() => iser_cma_handler() => iser_route_handler()
=> iser_create_ib_conn_res()

We fail here and return failures back down the tree.

iser_connect() => iser_conn_release()

Double free.

I will send a patch for this tomorrow.

regards,
dan carpenter