Increment the refcnt for driver modules in current use by calling module_get in coresight_build_path and module_put in release_path.
This prevents driver modules from being unloaded when they are in use, either in sysfs or perf mode. Cc: Mathieu Poirier <[email protected]> Cc: Leo Yan <[email protected]> Cc: Alexander Shishkin <[email protected]> Cc: Randy Dunlap <[email protected]> Cc: Suzuki K Poulose <[email protected]> Cc: Greg Kroah-Hartman <[email protected]> Cc: Russell King <[email protected]> Signed-off-by: Kim Phillips <[email protected]> --- drivers/hwtracing/coresight/coresight.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/drivers/hwtracing/coresight/coresight.c b/drivers/hwtracing/coresight/coresight.c index 338f1719641c..1c941351f1d1 100644 --- a/drivers/hwtracing/coresight/coresight.c +++ b/drivers/hwtracing/coresight/coresight.c @@ -465,6 +465,12 @@ static int _coresight_build_path(struct coresight_device *csdev, node->csdev = csdev; list_add(&node->link, path); + + if (!try_module_get(csdev->dev.parent->driver->owner)) { + dev_err(&csdev->dev, "could not get coresight driver module\n"); + return -ENODEV; + } + pm_runtime_get_sync(csdev->dev.parent); return 0; @@ -510,6 +516,9 @@ void coresight_release_path(struct list_head *path) csdev = nd->csdev; pm_runtime_put_sync(csdev->dev.parent); + + module_put(csdev->dev.parent->driver->owner); + list_del(&nd->link); kfree(nd); } -- 2.17.0
