drivers/net: remove some rcu sparse warnings

Add missing __rcu annotations and helpers.
minor : Fix some rcu_dereference() calls in macvtap

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

8 files changed, 40 insertions, 25 deletions

diff --git a/drivers/net/bnx2.c b/drivers/net/bnx2.c
index 3dbaf58f681..2a961b7f7e1 100644
--- a/drivers/net/bnx2.c
+++ b/drivers/net/bnx2.c
@@ -435,7 +435,8 @@ bnx2_cnic_stop(struct bnx2 *bp)
         struct cnic_ctl_info info;
 
         mutex_lock(&bp->cnic_lock);
-        c_ops = bp->cnic_ops;
+        c_ops = rcu_dereference_protected(bp->cnic_ops,
+                                          lockdep_is_held(&bp->cnic_lock));
         if (c_ops) {
                 info.cmd = CNIC_CTL_STOP_CMD;
                 c_ops->cnic_ctl(bp->cnic_data, &info);
@@ -450,7 +451,8 @@ bnx2_cnic_start(struct bnx2 *bp)
         struct cnic_ctl_info info;
 
         mutex_lock(&bp->cnic_lock);
-        c_ops = bp->cnic_ops;
+        c_ops = rcu_dereference_protected(bp->cnic_ops,
+                                          lockdep_is_held(&bp->cnic_lock));
         if (c_ops) {
                 if (!(bp->flags & BNX2_FLAG_USING_MSIX)) {
                         struct bnx2_napi *bnapi = &bp->bnx2_napi[0];
diff --git a/drivers/net/bnx2.h b/drivers/net/bnx2.h
index f459fb2f9ad..0132ea95999 100644
--- a/drivers/net/bnx2.h
+++ b/drivers/net/bnx2.h
@@ -6759,7 +6759,7 @@ struct bnx2 {
         u32             tx_wake_thresh;
 
 #ifdef BCM_CNIC
-        struct cnic_ops         *cnic_ops;
+        struct cnic_ops __rcu   *cnic_ops;
         void                    *cnic_data;
 #endif
 
diff --git a/drivers/net/bnx2x/bnx2x.h b/drivers/net/bnx2x/bnx2x.h
index 8e4183717d9..dfdb9b51ae5 100644
--- a/drivers/net/bnx2x/bnx2x.h
+++ b/drivers/net/bnx2x/bnx2x.h
@@ -1110,7 +1110,7 @@ struct bnx2x {
 #define BNX2X_CNIC_FLAG_MAC_SET         1
         void                    *t2;
         dma_addr_t              t2_mapping;
-        struct cnic_ops         *cnic_ops;
+        struct cnic_ops __rcu   *cnic_ops;
         void                    *cnic_data;
         u32                     cnic_tag;
         struct cnic_eth_dev     cnic_eth_dev;
diff --git a/drivers/net/bnx2x/bnx2x_main.c b/drivers/net/bnx2x/bnx2x_main.c
index 8cdcf5b39d1..a2a1bc43a1d 100644
--- a/drivers/net/bnx2x/bnx2x_main.c
+++ b/drivers/net/bnx2x/bnx2x_main.c
@@ -9862,7 +9862,8 @@ static int bnx2x_cnic_ctl_send(struct bnx2x *bp, struct cnic_ctl_info *ctl)
         int rc = 0;
 
         mutex_lock(&bp->cnic_mutex);
-        c_ops = bp->cnic_ops;
+        c_ops = rcu_dereference_protected(bp->cnic_ops,
+                                          lockdep_is_held(&bp->cnic_mutex));
         if (c_ops)
                 rc = c_ops->cnic_ctl(bp->cnic_data, ctl);
         mutex_unlock(&bp->cnic_mutex);
diff --git a/drivers/net/cnic.c b/drivers/net/cnic.c
index 7ff170cbc7d..c8204963513 100644
--- a/drivers/net/cnic.c
+++ b/drivers/net/cnic.c
@@ -65,7 +65,14 @@ static LIST_HEAD(cnic_udev_list);
 static DEFINE_RWLOCK(cnic_dev_lock);
 static DEFINE_MUTEX(cnic_lock);
 
-static struct cnic_ulp_ops *cnic_ulp_tbl[MAX_CNIC_ULP_TYPE];
+static struct cnic_ulp_ops __rcu *cnic_ulp_tbl[MAX_CNIC_ULP_TYPE];
+
+/* helper function, assuming cnic_lock is held */
+static inline struct cnic_ulp_ops *cnic_ulp_tbl_prot(int type)
+{
+        return rcu_dereference_protected(cnic_ulp_tbl[type],
+                                         lockdep_is_held(&cnic_lock));
+}
 
 static int cnic_service_bnx2(void *, void *);
 static int cnic_service_bnx2x(void *, void *);
@@ -435,7 +442,7 @@ int cnic_register_driver(int ulp_type, struct cnic_ulp_ops *ulp_ops)
                 return -EINVAL;
         }
         mutex_lock(&cnic_lock);
-        if (cnic_ulp_tbl[ulp_type]) {
+        if (cnic_ulp_tbl_prot(ulp_type)) {
                 pr_err("%s: Type %d has already been registered\n",
                        __func__, ulp_type);
                 mutex_unlock(&cnic_lock);
@@ -478,7 +485,7 @@ int cnic_unregister_driver(int ulp_type)
                 return -EINVAL;
         }
         mutex_lock(&cnic_lock);
-        ulp_ops = cnic_ulp_tbl[ulp_type];
+        ulp_ops = cnic_ulp_tbl_prot(ulp_type);
         if (!ulp_ops) {
                 pr_err("%s: Type %d has not been registered\n",
                        __func__, ulp_type);
@@ -529,7 +536,7 @@ static int cnic_register_device(struct cnic_dev *dev, int ulp_type,
                 return -EINVAL;
         }
         mutex_lock(&cnic_lock);
-        if (cnic_ulp_tbl[ulp_type] == NULL) {
+        if (cnic_ulp_tbl_prot(ulp_type) == NULL) {
                 pr_err("%s: Driver with type %d has not been registered\n",
                        __func__, ulp_type);
                 mutex_unlock(&cnic_lock);
@@ -544,7 +551,7 @@ static int cnic_register_device(struct cnic_dev *dev, int ulp_type,
 
         clear_bit(ULP_F_START, &cp->ulp_flags[ulp_type]);
         cp->ulp_handle[ulp_type] = ulp_ctx;
-        ulp_ops = cnic_ulp_tbl[ulp_type];
+        ulp_ops = cnic_ulp_tbl_prot(ulp_type);
         rcu_assign_pointer(cp->ulp_ops[ulp_type], ulp_ops);
         cnic_hold(dev);
 
@@ -2953,7 +2960,8 @@ static void cnic_ulp_stop(struct cnic_dev *dev)
                 struct cnic_ulp_ops *ulp_ops;
 
                 mutex_lock(&cnic_lock);
-                ulp_ops = cp->ulp_ops[if_type];
+                ulp_ops = rcu_dereference_protected(cp->ulp_ops[if_type],
+                                                    lockdep_is_held(&cnic_lock));
                 if (!ulp_ops) {
                         mutex_unlock(&cnic_lock);
                         continue;
@@ -2977,7 +2985,8 @@ static void cnic_ulp_start(struct cnic_dev *dev)
                 struct cnic_ulp_ops *ulp_ops;
 
                 mutex_lock(&cnic_lock);
-                ulp_ops = cp->ulp_ops[if_type];
+                ulp_ops = rcu_dereference_protected(cp->ulp_ops[if_type],
+                                                    lockdep_is_held(&cnic_lock));
                 if (!ulp_ops || !ulp_ops->cnic_start) {
                         mutex_unlock(&cnic_lock);
                         continue;
@@ -3041,7 +3050,7 @@ static void cnic_ulp_init(struct cnic_dev *dev)
                 struct cnic_ulp_ops *ulp_ops;
 
                 mutex_lock(&cnic_lock);
-                ulp_ops = cnic_ulp_tbl[i];
+                ulp_ops = cnic_ulp_tbl_prot(i);
                 if (!ulp_ops || !ulp_ops->cnic_init) {
                         mutex_unlock(&cnic_lock);
                         continue;
@@ -3065,7 +3074,7 @@ static void cnic_ulp_exit(struct cnic_dev *dev)
                 struct cnic_ulp_ops *ulp_ops;
 
                 mutex_lock(&cnic_lock);
-                ulp_ops = cnic_ulp_tbl[i];
+                ulp_ops = cnic_ulp_tbl_prot(i);
                 if (!ulp_ops || !ulp_ops->cnic_exit) {
                         mutex_unlock(&cnic_lock);
                         continue;
diff --git a/drivers/net/cnic.h b/drivers/net/cnic.h
index b328f6c924c..4456260c653 100644
--- a/drivers/net/cnic.h
+++ b/drivers/net/cnic.h
@@ -220,7 +220,7 @@ struct cnic_local {
 #define ULP_F_INIT      0
 #define ULP_F_START     1
 #define ULP_F_CALL_PENDING      2
-        struct cnic_ulp_ops *ulp_ops[MAX_CNIC_ULP_TYPE];
+        struct cnic_ulp_ops __rcu *ulp_ops[MAX_CNIC_ULP_TYPE];
 
         unsigned long cnic_local_flags;
 #define CNIC_LCL_FL_KWQ_INIT            0x0
diff --git a/drivers/net/hamradio/bpqether.c b/drivers/net/hamradio/bpqether.c
index ac1d323c5eb..8931168d3e7 100644
--- a/drivers/net/hamradio/bpqether.c
+++ b/drivers/net/hamradio/bpqether.c
@@ -400,13 +400,14 @@ static void *bpq_seq_start(struct seq_file *seq, loff_t *pos)
 static void *bpq_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 {
         struct list_head *p;
+        struct bpqdev *bpqdev = v;
 
         ++*pos;
 
         if (v == SEQ_START_TOKEN)
-                p = rcu_dereference(bpq_devices.next);
+                p = rcu_dereference(list_next_rcu(&bpq_devices));
         else
-                p = rcu_dereference(((struct bpqdev *)v)->bpq_list.next);
+                p = rcu_dereference(list_next_rcu(&bpqdev->bpq_list));
 
         return (p == &bpq_devices) ? NULL 
                 : list_entry(p, struct bpqdev, bpq_list);
diff --git a/drivers/net/macvtap.c b/drivers/net/macvtap.c
index 5933621ac3f..2300e459952 100644
--- a/drivers/net/macvtap.c
+++ b/drivers/net/macvtap.c
@@ -39,7 +39,7 @@ struct macvtap_queue {
         struct socket sock;
         struct socket_wq wq;
         int vnet_hdr_sz;
-        struct macvlan_dev *vlan;
+        struct macvlan_dev __rcu *vlan;
         struct file *file;
         unsigned int flags;
 };
@@ -141,7 +141,8 @@ static void macvtap_put_queue(struct macvtap_queue *q)
         struct macvlan_dev *vlan;
 
         spin_lock(&macvtap_lock);
-        vlan = rcu_dereference(q->vlan);
+        vlan = rcu_dereference_protected(q->vlan,
+                                         lockdep_is_held(&macvtap_lock));
         if (vlan) {
                 int index = get_slot(vlan, q);
 
@@ -219,7 +220,8 @@ static void macvtap_del_queues(struct net_device *dev)
         /* macvtap_put_queue can free some slots, so go through all slots */
         spin_lock(&macvtap_lock);
         for (i = 0; i < MAX_MACVTAP_QUEUES && vlan->numvtaps; i++) {
-                q = rcu_dereference(vlan->taps[i]);
+                q = rcu_dereference_protected(vlan->taps[i],
+                                              lockdep_is_held(&macvtap_lock));
                 if (q) {
                         qlist[j++] = q;
                         rcu_assign_pointer(vlan->taps[i], NULL);
@@ -569,7 +571,7 @@ static ssize_t macvtap_get_user(struct macvtap_queue *q,
         }
 
         rcu_read_lock_bh();
-        vlan = rcu_dereference(q->vlan);
+        vlan = rcu_dereference_bh(q->vlan);
         if (vlan)
                 macvlan_start_xmit(skb, vlan->dev);
         else
@@ -583,7 +585,7 @@ err_kfree:
 
 err:
         rcu_read_lock_bh();
-        vlan = rcu_dereference(q->vlan);
+        vlan = rcu_dereference_bh(q->vlan);
         if (vlan)
                 vlan->dev->stats.tx_dropped++;
         rcu_read_unlock_bh();
@@ -631,7 +633,7 @@ static ssize_t macvtap_put_user(struct macvtap_queue *q,
         ret = skb_copy_datagram_const_iovec(skb, 0, iv, vnet_hdr_len, len);
 
         rcu_read_lock_bh();
-        vlan = rcu_dereference(q->vlan);
+        vlan = rcu_dereference_bh(q->vlan);
         if (vlan)
                 macvlan_count_rx(vlan, len, ret == 0, 0);
         rcu_read_unlock_bh();
@@ -727,7 +729,7 @@ static long macvtap_ioctl(struct file *file, unsigned int cmd,
 
         case TUNGETIFF:
                 rcu_read_lock_bh();
-                vlan = rcu_dereference(q->vlan);
+                vlan = rcu_dereference_bh(q->vlan);
                 if (vlan)
                         dev_hold(vlan->dev);
                 rcu_read_unlock_bh();
@@ -736,7 +738,7 @@ static long macvtap_ioctl(struct file *file, unsigned int cmd,
                         return -ENOLINK;
 
                 ret = 0;
-                if (copy_to_user(&ifr->ifr_name, q->vlan->dev->name, IFNAMSIZ) ||
+                if (copy_to_user(&ifr->ifr_name, vlan->dev->name, IFNAMSIZ) ||
                     put_user(q->flags, &ifr->ifr_flags))
                         ret = -EFAULT;
                 dev_put(vlan->dev);