Make sure to drop the reference taken when looking up the th device during output device open() on errors and on close().

Fixes: 39f4034693b7 ("intel_th: Add driver infrastructure for Intel(R) Trace Hub devices") Cc: stable@vger.kernel.org # 4.4 Cc: Alexander Shishkin alexander.shishkin@linux.intel.com Signed-off-by: Johan Hovold johan@kernel.org ---

Hit send too soon...

Changes in v2: - drop reference also on the last error path

drivers/hwtracing/intel_th/core.c | 30 ++++++++++++++++++++++++++---- 1 file changed, 26 insertions(+), 4 deletions(-)

diff --git a/drivers/hwtracing/intel_th/core.c b/drivers/hwtracing/intel_th/core.c index 47d9e6c3bac0..bc38814e6802 100644 --- a/drivers/hwtracing/intel_th/core.c +++ b/drivers/hwtracing/intel_th/core.c @@ -810,13 +810,20 @@ static int intel_th_output_open(struct inode *inode, struct file *file) int err;

dev = bus_find_device_by_devt(&intel_th_bus, inode->i_rdev); - if (!dev || !dev->driver) + if (!dev) return -ENODEV;

+ if (!dev->driver) { + err = -ENODEV; + goto err_put_dev; + } + thdrv = to_intel_th_driver(dev->driver); fops = fops_get(thdrv->fops); - if (!fops) - return -ENODEV; + if (!fops) { + err = -ENODEV; + goto err_put_dev; + }

replace_fops(file, fops);

@@ -824,14 +831,29 @@ static int intel_th_output_open(struct inode *inode, struct file *file)

if (file->f_op->open) { err = file->f_op->open(inode, file); - return err; + goto err_put_dev; }

+ return 0; + +err_put_dev: + put_device(dev); + + return err; +} + +static int intel_th_output_release(struct inode *inode, struct file *file) +{ + struct intel_th_device *thdev = file->private_data; + + put_device(&thdev->dev); + return 0; }

static const struct file_operations intel_th_output_fops = { .open = intel_th_output_open, + .release = intel_th_output_release, .llseek = noop_llseek, };