[PATCH] gpudev: fix deadlocks when registering callback

[David Marchand]

gpu_callback_lock was not released in some branches of the register
helper.
While at it, set rte_errno in one branch.

Fixes: 18cb07563165 ("gpudev: add event notification")
Cc: stable at dpdk.org

Signed-off-by: David Marchand <david.marchand at redhat.com>
---
 lib/gpudev/gpudev.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/lib/gpudev/gpudev.c b/lib/gpudev/gpudev.c
index 805719d00c..8f12abef23 100644
--- a/lib/gpudev/gpudev.c
+++ b/lib/gpudev/gpudev.c
@@ -408,6 +408,7 @@ rte_gpu_callback_register(int16_t dev_id, enum rte_gpu_event event,
 					callback->function == function &&
 					callback->user_data == user_data) {
 				GPU_LOG(INFO, "callback already registered");
+				rte_rwlock_write_unlock(&gpu_callback_lock);
 				return 0;
 			}
 		}
@@ -415,7 +416,9 @@ rte_gpu_callback_register(int16_t dev_id, enum rte_gpu_event event,
 		callback = malloc(sizeof(*callback));
 		if (callback == NULL) {
 			GPU_LOG(ERR, "cannot allocate callback");
-			return -ENOMEM;
+			rte_rwlock_write_unlock(&gpu_callback_lock);
+			rte_errno = ENOMEM;
+			return -rte_errno;
 		}
 		callback->function = function;
 		callback->user_data = user_data;
-- 
2.39.0