[PATCH v2 4/9] coresight: Fix csdev connections initialisation

On 12/06/16 21:39, Mathieu Poirier wrote:

On 6 June 2016 at 03:11, Suzuki K Poulose [off-list ref] wrote:

quoted

This is a cleanup patch.

coresight_device->conns holds an array to point to the devices
connected to the OUT ports of a component. Sinks, e.g ETR, do not
have an OUT port (nr_outport = 0), as it streams the trace to
memory via AXI.

At coresight_register() we do :

         conns = kcalloc(csdev->nr_outport, sizeof(*conns), GFP_KERNEL);
         if (!conns) {
                 ret = -ENOMEM;
                 goto err_kzalloc_conns;
         }

For ETR, since the total size requested for kcalloc is zero, the return
value is, ZERO_SIZE_PTR ( != NULL). Hence, csdev->conns = ZERO_SIZE_PTR
which cannot be verified later to contain a valid pointer. The code which
accesses the csdev->conns is bounded by the csdev->nr_outport check,
hence we don't try to dereference the ZERO_SIZE_PTR. This patch cleans
up the csdev->conns and csdev->refcnt, initialisation to make sure we

This patch no longer deals with csdev->refcnt.

Ok, fill fix that. Btw, do we need that check ? I am tempted to keep it there,
just to make sure we don't end up in something similar in the future.

Cheers
Suzuki