pcmcia: protect s->device_count
Dominik Brodowski [Sat, 16 Jan 2010 00:34:06 +0000 (01:34 +0100)]
Tested-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>

drivers/pcmcia/ds.c

index 4f7308d..bcb9ef1 100644 (file)
@@ -265,6 +265,7 @@ static int pcmcia_device_probe(struct device *dev)
        struct pcmcia_device_id *did;
        struct pcmcia_socket *s;
        cistpl_config_t cis_config;
+       unsigned long flags;
        int ret = 0;
 
        dev = get_device(dev);
@@ -315,9 +316,11 @@ static int pcmcia_device_probe(struct device *dev)
                goto put_module;
        }
 
+       spin_lock_irqsave(&pcmcia_dev_list_lock, flags);
        if (did && (did->match_flags & PCMCIA_DEV_ID_MATCH_DEVICE_NO) &&
            (p_dev->socket->device_count == 1) && (p_dev->device_no == 0))
                pcmcia_add_device_later(p_dev->socket, 0);
+       spin_unlock_irqrestore(&pcmcia_dev_list_lock, flags);
 
 put_module:
        if (ret)
@@ -342,10 +345,12 @@ static void pcmcia_card_remove(struct pcmcia_socket *s, struct pcmcia_device *le
                   "pcmcia_card_remove(%d) %s\n", s->sock,
                   leftover ? leftover->devname : "");
 
+       spin_lock_irqsave(&pcmcia_dev_list_lock, flags);
        if (!leftover)
                s->device_count = 0;
        else
                s->device_count = 1;
+       spin_unlock_irqrestore(&pcmcia_dev_list_lock, flags);
 
        /* unregister all pcmcia_devices registered with this socket, except leftover */
        list_for_each_entry_safe(p_dev, tmp, &s->devices_list, socket_device_list) {
@@ -382,7 +387,7 @@ static int pcmcia_device_remove(struct device *dev)
         */
        did = dev_get_drvdata(&p_dev->dev);
        if (did && (did->match_flags & PCMCIA_DEV_ID_MATCH_DEVICE_NO) &&
-           (p_dev->socket->device_count != 0) &&
+           (p_dev->socket->device_count > 0) &&
            (p_dev->device_no == 0))
                pcmcia_card_remove(p_dev->socket, p_dev);
 
@@ -512,16 +517,19 @@ struct pcmcia_device *pcmcia_device_add(struct pcmcia_socket *s, unsigned int fu
 
        pr_debug("adding device to %d, function %d\n", s->sock, function);
 
-       /* max of 4 devices per card */
-       if (s->device_count == 4)
-               goto err_put;
-
        p_dev = kzalloc(sizeof(struct pcmcia_device), GFP_KERNEL);
        if (!p_dev)
                goto err_put;
 
-       p_dev->socket = s;
+       spin_lock_irqsave(&pcmcia_dev_list_lock, flags);
        p_dev->device_no = (s->device_count++);
+       spin_unlock_irqrestore(&pcmcia_dev_list_lock, flags);
+
+       /* max of 4 devices per card */
+       if (p_dev->device_no >= 4)
+               goto err_free;
+
+       p_dev->socket = s;
        p_dev->func   = function;
 
        p_dev->dev.bus = &pcmcia_bus_type;
@@ -586,9 +594,12 @@ struct pcmcia_device *pcmcia_device_add(struct pcmcia_socket *s, unsigned int fu
        spin_unlock_irqrestore(&pcmcia_dev_list_lock, flags);
 
  err_free:
+       spin_lock_irqsave(&pcmcia_dev_list_lock, flags);
+       s->device_count--;
+       spin_unlock_irqrestore(&pcmcia_dev_list_lock, flags);
+
        kfree(p_dev->devname);
        kfree(p_dev);
-       s->device_count--;
  err_put:
        mutex_unlock(&device_add_lock);
        pcmcia_put_socket(s);