rcu: Replace rcu_dereference() with rcu_access_pointer()

PATCH Superseded Andreea-Cristina Bernat 1 participant 1 message Aug 16, 2014

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Andreea-Cristina Bernat

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2014-08-16 20:12 UTC #0 lore raw

PATCH 1/1 rcu: Replace rcu_dereference() with rcu_access_pointer()

The "rcu_dereference()" calls are used directly in conditions. Since their return values are never dereferenced it is recommended to use "rcu_access_pointer()" instead of "rcu_dereference()". Therefore, this patch makes the replacements.

The following Coccinelle semantic patch was used:
@@
@@

(
if(
(<+...
- rcu_dereference
+ rcu_access_pointer
(...)
...+>)) {...}
|
while(
(<+...
- rcu_dereference
+ rcu_access_pointer
(...)
...+>)) {...}
)

Signed-off-by Andreea-Cristina Bernat <[email protected]>

---
 drivers/net/ethernet/broadcom/cnic.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

drivers/net/ethernet/broadcom/cnic.c +3 -3

index 8244e2b..dad9cb7 100644
@@ -381,7 +381,7 @@ static int cnic_iscsi_nl_msg_recv(struct cnic_dev *dev, u32 msg_type,
 			break;
 
 		rcu_read_lock();
-		if (!rcu_dereference(cp->ulp_ops[CNIC_ULP_L4])) {
+		if (!rcu_access_pointer(cp->ulp_ops[CNIC_ULP_L4])) {
 			rc = -ENODEV;
 			rcu_read_unlock();
 			break;

@@ -525,7 +525,7 @@ int cnic_unregister_driver(int ulp_type)
 	list_for_each_entry(dev, &cnic_dev_list, list) {
 		struct cnic_local *cp = dev->cnic_priv;
 
-		if (rcu_dereference(cp->ulp_ops[ulp_type])) {
+		if (rcu_access_pointer(cp->ulp_ops[ulp_type])) {
 			pr_err("%s: Type %d still has devices registered\n",
 			       __func__, ulp_type);
 			read_unlock(&cnic_dev_lock);

@@ -573,7 +573,7 @@ static int cnic_register_device(struct cnic_dev *dev, int ulp_type,
 		mutex_unlock(&cnic_lock);
 		return -EAGAIN;
 	}
-	if (rcu_dereference(cp->ulp_ops[ulp_type])) {
+	if (rcu_access_pointer(cp->ulp_ops[ulp_type])) {
 		pr_err("%s: Type %d has already been registered to this device\n",
 		       __func__, ulp_type);
 		mutex_unlock(&cnic_lock);

Signature · 1 line

1.9.1