Messages in this thread | | | From | Mathieu Poirier <> | Date | Mon, 13 Jun 2016 08:37:35 -0600 | Subject | Re: [PATCH v2 4/9] coresight: Fix csdev connections initialisation |
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On 13 June 2016 at 02:54, Suzuki K Poulose <Suzuki.Poulose@arm.com> wrote: > On 12/06/16 21:39, Mathieu Poirier wrote: >> >> On 6 June 2016 at 03:11, Suzuki K Poulose <suzuki.poulose@arm.com> wrote: >>> >>> 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.
If it becomes an issue in the future we'll know what to do :o)
Thanks, Mathieu
> > Cheers > Suzuki
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