[PATCH] DVB: Fix locking to prevent Oops on SMP systems

Fix locking to prevent Oops on SMP systems when starting/stopping dvb network
interfaces.

Signed-off-by: Ralph Metzler <rjkm@metzlerbros.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@brturbo.com.br>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

diff --git a/drivers/media/dvb/dvb-core/dvb_net.c b/drivers/media/dvb/dvb-core/dvb_net.c
index 87935490bfb2f1e4deb34c0bea36ff5de3cf4c7c..df536bd2e103b85690645511753fd0b83a29aab8 100644 (file)
--- a/drivers/media/dvb/dvb-core/dvb_net.c
+++ b/drivers/media/dvb/dvb-core/dvb_net.c
@@ -151,6 +151,8 @@ struct dvb_net_priv {
        unsigned char ule_bridged;              /* Whether the ULE_BRIDGED extension header was found. */
        int ule_sndu_remain;                    /* Nr. of bytes still required for current ULE SNDU. */
        unsigned long ts_count;                 /* Current ts cell counter. */
+
+       struct semaphore mutex;
 };
 
 
@@ -881,12 +883,13 @@ static int dvb_net_filter_sec_set(struct net_device *dev,
 
 static int dvb_net_feed_start(struct net_device *dev)
 {
-       int ret, i;
+       int ret = 0, i;
        struct dvb_net_priv *priv = dev->priv;
         struct dmx_demux *demux = priv->demux;
         unsigned char *mac = (unsigned char *) dev->dev_addr;
 
        dprintk("%s: rx_mode %i\n", __FUNCTION__, priv->rx_mode);
+       down(&priv->mutex);
        if (priv->tsfeed || priv->secfeed || priv->secfilter || priv->multi_secfilter[0])
                printk("%s: BUG %d\n", __FUNCTION__, __LINE__);
 
@@ -900,7 +903,7 @@ static int dvb_net_feed_start(struct net_device *dev)
                                         dvb_net_sec_callback);
                if (ret<0) {
                        printk("%s: could not allocate section feed\n", dev->name);
-                       return ret;
+                       goto error;
                }
 
                ret = priv->secfeed->set(priv->secfeed, priv->pid, 32768, 1);
@@ -909,7 +912,7 @@ static int dvb_net_feed_start(struct net_device *dev)
                        printk("%s: could not set section feed\n", dev->name);
                        priv->demux->release_section_feed(priv->demux, priv->secfeed);
                        priv->secfeed=NULL;
-                       return ret;
+                       goto error;
                }
 
                if (priv->rx_mode != RX_MODE_PROMISC) {
@@ -948,7 +951,7 @@ static int dvb_net_feed_start(struct net_device *dev)
                ret = demux->allocate_ts_feed(demux, &priv->tsfeed, dvb_net_ts_callback);
                if (ret < 0) {
                        printk("%s: could not allocate ts feed\n", dev->name);
-                       return ret;
+                       goto error;
                }
 
                /* Set netdevice pointer for ts decaps callback. */
@@ -962,23 +965,26 @@ static int dvb_net_feed_start(struct net_device *dev)
                        printk("%s: could not set ts feed\n", dev->name);
                        priv->demux->release_ts_feed(priv->demux, priv->tsfeed);
                        priv->tsfeed = NULL;
-                       return ret;
+                       goto error;
                }
 
                dprintk("%s: start filtering\n", __FUNCTION__);
                priv->tsfeed->start_filtering(priv->tsfeed);
        } else
-               return -EINVAL;
+               ret = -EINVAL;
 
-       return 0;
+error:
+       up(&priv->mutex);
+       return ret;
 }
 
 static int dvb_net_feed_stop(struct net_device *dev)
 {
        struct dvb_net_priv *priv = dev->priv;
-       int i;
+       int i, ret = 0;
 
        dprintk("%s\n", __FUNCTION__);
+       down(&priv->mutex);
        if (priv->feedtype == DVB_NET_FEEDTYPE_MPE) {
                if (priv->secfeed) {
                        if (priv->secfeed->is_filtering) {
@@ -1019,8 +1025,9 @@ static int dvb_net_feed_stop(struct net_device *dev)
                else
                        printk("%s: no ts feed to stop\n", dev->name);
        } else
-               return -EINVAL;
-       return 0;
+               ret = -EINVAL;
+       up(&priv->mutex);
+       return ret;
 }
 
 
@@ -1044,8 +1051,8 @@ static void wq_set_multicast_list (void *data)
        struct dvb_net_priv *priv = dev->priv;
 
        dvb_net_feed_stop(dev);
-
        priv->rx_mode = RX_MODE_UNI;
+       spin_lock_bh(&dev->xmit_lock);
 
        if (dev->flags & IFF_PROMISC) {
                dprintk("%s: promiscuous mode\n", dev->name);
@@ -1070,6 +1077,7 @@ static void wq_set_multicast_list (void *data)
                }
        }
 
+       spin_unlock_bh(&dev->xmit_lock);
        dvb_net_feed_start(dev);
 }
 
@@ -1200,6 +1208,7 @@ static int dvb_net_add_if(struct dvb_net *dvbnet, u16 pid, u8 feedtype)
 
        INIT_WORK(&priv->set_multicast_list_wq, wq_set_multicast_list, net);
        INIT_WORK(&priv->restart_net_feed_wq, wq_restart_net_feed, net);
+       init_MUTEX(&priv->mutex);
 
        net->base_addr = pid;