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author | Suzuki K Poulose <suzuki.poulose@arm.com> | 2019-06-21 11:52:04 -0600 |
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committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-07-03 21:16:36 +0200 |
commit | 020601622323d02e09cebe05e7976b3d4b44e05d (patch) | |
tree | 87131bddf35a628daf522374f4a95c92935551b4 /drivers/hwtracing | |
parent | 0530ef6b41e80c5cc979e0e50682302161edb6b7 (diff) | |
download | linux-020601622323d02e09cebe05e7976b3d4b44e05d.tar.gz linux-020601622323d02e09cebe05e7976b3d4b44e05d.tar.bz2 linux-020601622323d02e09cebe05e7976b3d4b44e05d.zip |
coresight: etm3x: Smatch: Fix potential NULL pointer dereference
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>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Link: https://lore.kernel.org/r/20190621175205.24551-2-mathieu.poirier@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/hwtracing')
-rw-r--r-- | drivers/hwtracing/coresight/coresight-etm3x.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/hwtracing/coresight/coresight-etm3x.c b/drivers/hwtracing/coresight/coresight-etm3x.c index bed729140718..225c2982e4fe 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; |