From: Suzuki K Poulose <suzuki.poulose@arm.com>
To: linux-arm-kernel@lists.infradead.org
Cc: mathieu.poirier@linaro.org, linux-kernel@vger.kernel.org,
Suzuki K Poulose <suzuki.poulose@arm.com>
Subject: [PATCH 3/5] coresight: Fix csdev connections initialisation
Date: Tue, 31 May 2016 12:57:36 +0100 [thread overview]
Message-ID: <1464695858-29284-4-git-send-email-suzuki.poulose@arm.com> (raw)
In-Reply-To: <1464695858-29284-1-git-send-email-suzuki.poulose@arm.com>
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 initialise it properly(i.e, either NULL or valid conns array).
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
---
drivers/hwtracing/coresight/coresight.c | 42 +++++++++++++++++++--------------
1 file changed, 24 insertions(+), 18 deletions(-)
diff --git a/drivers/hwtracing/coresight/coresight.c b/drivers/hwtracing/coresight/coresight.c
index 0fdaaf4..8410420 100644
--- a/drivers/hwtracing/coresight/coresight.c
+++ b/drivers/hwtracing/coresight/coresight.c
@@ -890,7 +890,7 @@ struct coresight_device *coresight_register(struct coresight_desc *desc)
int nr_refcnts = 1;
atomic_t *refcnts = NULL;
struct coresight_device *csdev;
- struct coresight_connection *conns;
+ struct coresight_connection *conns = NULL;
csdev = kzalloc(sizeof(*csdev), GFP_KERNEL);
if (!csdev) {
@@ -908,29 +908,35 @@ struct coresight_device *coresight_register(struct coresight_desc *desc)
nr_refcnts = desc->pdata->nr_outport;
}
- refcnts = kcalloc(nr_refcnts, sizeof(*refcnts), GFP_KERNEL);
- if (!refcnts) {
- ret = -ENOMEM;
- goto err_kzalloc_refcnts;
- }
+ if (nr_refcnts) {
+ refcnts = kcalloc(nr_refcnts, sizeof(*refcnts), GFP_KERNEL);
+ if (!refcnts) {
+ ret = -ENOMEM;
+ goto err_kzalloc_refcnts;
+ }
- csdev->refcnt = refcnts;
+ csdev->refcnt = refcnts;
+ }
csdev->nr_inport = desc->pdata->nr_inport;
csdev->nr_outport = desc->pdata->nr_outport;
- conns = kcalloc(csdev->nr_outport, sizeof(*conns), GFP_KERNEL);
- if (!conns) {
- ret = -ENOMEM;
- goto err_kzalloc_conns;
- }
- for (i = 0; i < csdev->nr_outport; i++) {
- conns[i].outport = desc->pdata->outports[i];
- conns[i].child_name = desc->pdata->child_names[i];
- conns[i].child_port = desc->pdata->child_ports[i];
- }
+ /* Initialise connections if there is at least one outport for this component */
+ if (csdev->nr_outport) {
+ conns = kcalloc(csdev->nr_outport, sizeof(*conns), GFP_KERNEL);
+ if (!conns) {
+ ret = -ENOMEM;
+ goto err_kzalloc_conns;
+ }
- csdev->conns = conns;
+ for (i = 0; i < csdev->nr_outport; i++) {
+ conns[i].outport = desc->pdata->outports[i];
+ conns[i].child_name = desc->pdata->child_names[i];
+ conns[i].child_port = desc->pdata->child_ports[i];
+ }
+
+ csdev->conns = conns;
+ }
csdev->type = desc->type;
csdev->subtype = desc->subtype;
--
1.9.1
next prev parent reply other threads:[~2016-05-31 11:58 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-05-31 11:57 [PATCH 0/5] coresight: Miscellaneous fixes Suzuki K Poulose
2016-05-31 11:57 ` [PATCH 1/5] coresight: Fix NULL pointer dereference in _coresight_build_path Suzuki K Poulose
2016-05-31 17:39 ` Mathieu Poirier
2016-05-31 11:57 ` [PATCH 2/5] coresight: etmv4: Fix ETMv4x peripheral ID table Suzuki K Poulose
2016-05-31 17:45 ` Mathieu Poirier
2016-05-31 11:57 ` Suzuki K Poulose [this message]
2016-05-31 17:55 ` [PATCH 3/5] coresight: Fix csdev connections initialisation Mathieu Poirier
2016-06-01 9:30 ` Suzuki K Poulose
2016-05-31 11:57 ` [PATCH 4/5] coresight: Add better messages for coresight_timeout Suzuki K Poulose
2016-05-31 17:57 ` Mathieu Poirier
2016-05-31 17:58 ` Joe Perches
2016-06-01 9:34 ` Suzuki K Poulose
2016-06-01 15:15 ` Mathieu Poirier
2016-05-31 11:57 ` [PATCH 5/5] coresight: Cleanup TMC status check Suzuki K Poulose
2016-05-31 18:01 ` Mathieu Poirier
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