[PATCH] coresight: tpdm: initialize spinlock before exposing sysfs

[yingchao]

From: Yingchao Deng <dengyingchao@xxxxxxxxxxxxxxx>

tpdm_probe() initializes drvdata->spinlock after coresight_register(), but
the sysfs attributes registered by coresight_register() use the spinlock.
This exposes a window where a concurrent sysfs write can lock an
uninitialized spinlock.

Initialize the spinlock before coresight_register().

Fixes: b3c71626a933 ("Coresight: Add coresight TPDM source driver")
Signed-off-by: Yingchao Deng <dengyingchao@xxxxxxxxxxxxxxx>
---
 drivers/hwtracing/coresight/coresight-tpdm.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-tpdm.c b/drivers/hwtracing/coresight/coresight-tpdm.c
index 8464edbba2d4..50d1351772b9 100644
--- a/drivers/hwtracing/coresight/coresight-tpdm.c
+++ b/drivers/hwtracing/coresight/coresight-tpdm.c
@@ -1457,12 +1457,12 @@ static int tpdm_probe(struct device *dev, struct resource *res)
 		desc.groups = tpdm_attr_grps;
 	else
 		desc.groups = static_tpdm_attr_grps;
+	spin_lock_init(&drvdata->spinlock);
+
 	drvdata->csdev = coresight_register(&desc);
 	if (IS_ERR(drvdata->csdev))
 		return PTR_ERR(drvdata->csdev);
 
-	spin_lock_init(&drvdata->spinlock);
-
 	return 0;
 }
 
-- 
2.33.0