| Message ID | 1560420386-4239-1-git-send-email-suzuki.poulose@arm.com (mailing list archive) |
|---|---|
| State | Mainlined |
| Commit | 020601622323d02e09cebe05e7976b3d4b44e05d |
| Headers | show |
| Series | [1/2] coresight: etm3x: Smatch: Fix potential NULL pointer dereference | expand |
On Thu, 13 Jun 2019 at 04:06, Suzuki K Poulose <suzuki.poulose@arm.com> wrote: > > Based on the following report from Smatch tool, make sure we have a > valid drvdata before we dereference it to find the real dev. > > The patch 21d26b905c05: "coresight: etm: Clean up device specific > data" from May 22, 2019, leads to the following Smatch complaint: > > ./drivers/hwtracing/coresight/coresight-etm3x.c:460 etm_get_trace_id() > warn: variable dereferenced before check 'drvdata' (see line 458) > > ./drivers/hwtracing/coresight/coresight-etm3x.c > 457 int trace_id = -1; > 458 struct device *etm_dev = drvdata->csdev->dev.parent; > ^^^^^^^^^ > New dereference > > 459 > 460 if (!drvdata) > ^^^^^^^^ > Checked too late. Delete the check? > > 461 goto out; > 462 > > Cc: Mathieu Poirier <mathieu.poirier@linaro.org> > Cc: Dan Carpenter <dan.carpenter@oracle.com> > Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> > --- > drivers/hwtracing/coresight/coresight-etm3x.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/drivers/hwtracing/coresight/coresight-etm3x.c b/drivers/hwtracing/coresight/coresight-etm3x.c > index bed7291..225c298 100644 > --- a/drivers/hwtracing/coresight/coresight-etm3x.c > +++ b/drivers/hwtracing/coresight/coresight-etm3x.c > @@ -455,11 +455,12 @@ int etm_get_trace_id(struct etm_drvdata *drvdata) > { > unsigned long flags; > int trace_id = -1; > - struct device *etm_dev = drvdata->csdev->dev.parent; > + struct device *etm_dev; > > if (!drvdata) > goto out; > > + etm_dev = drvdata->csdev->dev.parent; > if (!local_read(&drvdata->mode)) > return drvdata->traceid; > I have applied both patches in this set. Thanks, Mathieu > -- > 2.7.4 >
diff --git a/drivers/hwtracing/coresight/coresight-etm3x.c b/drivers/hwtracing/coresight/coresight-etm3x.c index bed7291..225c298 100644 --- a/drivers/hwtracing/coresight/coresight-etm3x.c +++ b/drivers/hwtracing/coresight/coresight-etm3x.c @@ -455,11 +455,12 @@ int etm_get_trace_id(struct etm_drvdata *drvdata) { unsigned long flags; int trace_id = -1; - struct device *etm_dev = drvdata->csdev->dev.parent; + struct device *etm_dev; if (!drvdata) goto out; + etm_dev = drvdata->csdev->dev.parent; if (!local_read(&drvdata->mode)) return drvdata->traceid;
Based on the following report from Smatch tool, make sure we have a valid drvdata before we dereference it to find the real dev. The patch 21d26b905c05: "coresight: etm: Clean up device specific data" from May 22, 2019, leads to the following Smatch complaint: ./drivers/hwtracing/coresight/coresight-etm3x.c:460 etm_get_trace_id() warn: variable dereferenced before check 'drvdata' (see line 458) ./drivers/hwtracing/coresight/coresight-etm3x.c 457 int trace_id = -1; 458 struct device *etm_dev = drvdata->csdev->dev.parent; ^^^^^^^^^ New dereference 459 460 if (!drvdata) ^^^^^^^^ Checked too late. Delete the check? 461 goto out; 462 Cc: Mathieu Poirier <mathieu.poirier@linaro.org> Cc: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> --- drivers/hwtracing/coresight/coresight-etm3x.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)