The function vhost_worker_destroy() will use struct vhost_task_fn and
selects the different mode based on the value of inherit_owner.

Signed-off-by: Cindy Lu <lulu@redhat.com>
---
 drivers/vhost/vhost.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index 8b7ddfb33c61..c17dc01febcc 100644
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -718,12 +718,14 @@ static void vhost_detach_mm(struct vhost_dev *dev)
 static void vhost_worker_destroy(struct vhost_dev *dev,
 				 struct vhost_worker *worker)
 {
-	if (!worker)
+	if (!worker && !worker->fn)
 		return;
 
 	WARN_ON(!llist_empty(&worker->work_list));
 	xa_erase(&dev->worker_xa, worker->id);
-	vhost_task_stop(worker->vtsk);
+	worker->fn->stop(dev->inherit_owner ? (void *)worker->vtsk :
+					      (void *)worker->task);
+	kfree(worker->fn);
 	kfree(worker);
 }
 
-- 
2.45.0

Hi Cindy,

kernel test robot noticed the following build warnings:

https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Cindy-Lu/vhost-Add-a-new-parameter-to-allow-user-select-kthread/20241105-153254
base:   https://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost.git linux-next
patch link:    https://lore.kernel.org/r/20241105072642.898710-7-lulu%40redhat.com
patch subject: [PATCH v3 6/9] vhost: Add kthread support in function vhost_worker_destroy()
config: x86_64-randconfig-161-20241106 (https://download.01.org/0day-ci/archive/20241107/202411071945.ExiEHgoX-lkp@intel.com/config)
compiler: clang version 19.1.3 (https://github.com/llvm/llvm-project ab51eccf88f5321e7c60591c5546b254b6afab99)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
| Closes: https://lore.kernel.org/r/202411071945.ExiEHgoX-lkp@intel.com/

New smatch warnings:
drivers/vhost/vhost.c:721 vhost_worker_destroy() error: we previously assumed 'worker' could be null (see line 721)

Old smatch warnings:
drivers/vhost/vhost.c:241 vhost_worker_queue() error: we previously assumed 'worker' could be null (see line 241)

vim +/worker +721 drivers/vhost/vhost.c

1cdaafa1b8b4ef Mike Christie 2023-06-26  718  static void vhost_worker_destroy(struct vhost_dev *dev,
1cdaafa1b8b4ef Mike Christie 2023-06-26  719  				 struct vhost_worker *worker)
1a5f8090c6de99 Mike Christie 2023-03-10  720  {
e4dec2edddbd54 Cindy Lu      2024-11-05 @721  	if (!worker && !worker->fn)

Same thing.  && vs ||.

1a5f8090c6de99 Mike Christie 2023-03-10  722  		return;
1a5f8090c6de99 Mike Christie 2023-03-10  723  
1cdaafa1b8b4ef Mike Christie 2023-06-26  724  	WARN_ON(!llist_empty(&worker->work_list));
1cdaafa1b8b4ef Mike Christie 2023-06-26  725  	xa_erase(&dev->worker_xa, worker->id);
e4dec2edddbd54 Cindy Lu      2024-11-05  726  	worker->fn->stop(dev->inherit_owner ? (void *)worker->vtsk :
e4dec2edddbd54 Cindy Lu      2024-11-05  727  					      (void *)worker->task);
e4dec2edddbd54 Cindy Lu      2024-11-05  728  	kfree(worker->fn);
1cdaafa1b8b4ef Mike Christie 2023-06-26  729  	kfree(worker);
1cdaafa1b8b4ef Mike Christie 2023-06-26  730  }

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki