share pool: Solve processing errors

of some abnormal branches

ascend inclusion
category: feature
bugzilla: NA
CVE: NA

-------------------------------------------------

1. sp_group_add_task: when spg invalid, low 32bits of
pointer spg will be returned. This will be considered
a correct spg id.

2.sp_alloc: The error branch goto out, then sp_mutex
will be unlocked incorrectly(since not be locked).
Signed-off-by: NZhou Guanghui <zhouguanghui1@huawei.com>
Signed-off-by: NTang Yizhou <tangyizhou@huawei.com>
Reviewed-by: NDing Tianhong <dingtianhong@huawei.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

mm/share_pool.c

@@ -516,10 +516,15 @@ int sp_group_add_task(int pid, int spg_id)
 		goto out_unlock;
 
 	spg = find_or_alloc_sp_group(spg_id);
-	if (IS_ERR(spg) || !spg_valid(spg)) {
+	if (IS_ERR(spg)) {
 		ret = PTR_ERR(spg);
 		goto out_put_task;
 	}
+
+	if (!spg_valid(spg)) {
+		ret = -ENODEV;
+		goto out_put_task;
+	}
 	atomic_inc(&spg->use_count);
 
 	/* access control permission check */
@@ -1191,8 +1196,7 @@ void *sp_alloc(unsigned long size, unsigned long sp_flags, int spg_id)
 		if (ret < 0 && (ret != -EEXIST)) {
 			pr_err("share pool: allocation failed due to add group error %d in DVPP pass through scenario",
 			       ret);
-			p = ERR_PTR(ret);
-			goto out;
+			return ERR_PTR(ret);
 		}
 		mutex_lock(&sp_mutex);
 		spg = current->mm->sp_group;