hostap: Protect against initialization interrupt

Use an irq spinlock to hold off the IRQ handler until
enough early card init is complete such that the handler
can run without faulting.

Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Cc: stable@kernel.org
Signed-off-by: John W. Linville <linville@tuxdriver.com>

diff --git a/drivers/net/wireless/hostap/hostap_cs.c b/drivers/net/wireless/hostap/hostap_cs.c
index db72461c486b50a2c90a3fa09e6ce6958eb99eac..29b31a694b59cc2140cf7b044757f29c5dfd9701 100644 (file)
--- a/drivers/net/wireless/hostap/hostap_cs.c
+++ b/drivers/net/wireless/hostap/hostap_cs.c
@@ -594,6 +594,7 @@ static int prism2_config(struct pcmcia_device *link)
        local_info_t *local;
        int ret = 1;
        struct hostap_cs_priv *hw_priv;
+       unsigned long flags;
 
        PDEBUG(DEBUG_FLOW, "prism2_config()\n");
 
@@ -625,9 +626,15 @@ static int prism2_config(struct pcmcia_device *link)
        local->hw_priv = hw_priv;
        hw_priv->link = link;
 
+       /*
+        * Make sure the IRQ handler cannot proceed until at least
+        * dev->base_addr is initialized.
+        */
+       spin_lock_irqsave(&local->irq_init_lock, flags);
+
        ret = pcmcia_request_irq(link, prism2_interrupt);
        if (ret)
-               goto failed;
+               goto failed_unlock;
 
        /*
         * This actually configures the PCMCIA socket -- setting up
@@ -636,11 +643,13 @@ static int prism2_config(struct pcmcia_device *link)
         */
        ret = pcmcia_request_configuration(link, &link->conf);
        if (ret)
-               goto failed;
+               goto failed_unlock;
 
        dev->irq = link->irq;
        dev->base_addr = link->io.BasePort1;
 
+       spin_unlock_irqrestore(&local->irq_init_lock, flags);
+
        /* Finally, report what we've done */
        printk(KERN_INFO "%s: index 0x%02x: ",
               dev_info, link->conf.ConfigIndex);
@@ -667,6 +676,8 @@ static int prism2_config(struct pcmcia_device *link)
 
        return ret;
 
+ failed_unlock:
+        spin_unlock_irqrestore(&local->irq_init_lock, flags);
  failed:
        kfree(hw_priv);
        prism2_release((u_long)link);

diff --git a/drivers/net/wireless/hostap/hostap_hw.c b/drivers/net/wireless/hostap/hostap_hw.c
index ff9b5c882184a00e58316166a62fd5514ead0ae6..2f999fc94f60ca9b36bb11d70fd29096c85eaf7e 100644 (file)
--- a/drivers/net/wireless/hostap/hostap_hw.c
+++ b/drivers/net/wireless/hostap/hostap_hw.c
@@ -2621,6 +2621,18 @@ static irqreturn_t prism2_interrupt(int irq, void *dev_id)
        iface = netdev_priv(dev);
        local = iface->local;
 
+       /* Detect early interrupt before driver is fully configued */
+       spin_lock(&local->irq_init_lock);
+       if (!dev->base_addr) {
+               if (net_ratelimit()) {
+                       printk(KERN_DEBUG "%s: Interrupt, but dev not configured\n",
+                              dev->name);
+               }
+               spin_unlock(&local->irq_init_lock);
+               return IRQ_HANDLED;
+       }
+       spin_unlock(&local->irq_init_lock);
+
        prism2_io_debug_add(dev, PRISM2_IO_DEBUG_CMD_INTERRUPT, 0, 0);
 
        if (local->func->card_present && !local->func->card_present(local)) {
@@ -3138,6 +3150,7 @@ prism2_init_local_data(struct prism2_helper_functions *funcs, int card_idx,
        spin_lock_init(&local->cmdlock);
        spin_lock_init(&local->baplock);
        spin_lock_init(&local->lock);
+       spin_lock_init(&local->irq_init_lock);
        mutex_init(&local->rid_bap_mtx);
 
        if (card_idx < 0 || card_idx >= MAX_PARM_DEVICES)

diff --git a/drivers/net/wireless/hostap/hostap_wlan.h b/drivers/net/wireless/hostap/hostap_wlan.h
index 3d238917af07f32bcd16ffcf8eb75f90f824b120..1ba33be98b254ce9ef8a56fcb6c55501d14a9839 100644 (file)
--- a/drivers/net/wireless/hostap/hostap_wlan.h
+++ b/drivers/net/wireless/hostap/hostap_wlan.h
@@ -654,7 +654,7 @@ struct local_info {
        rwlock_t iface_lock; /* hostap_interfaces read lock; use write lock
                              * when removing entries from the list.
                              * TX and RX paths can use read lock. */
-       spinlock_t cmdlock, baplock, lock;
+       spinlock_t cmdlock, baplock, lock, irq_init_lock;
        struct mutex rid_bap_mtx;
        u16 infofid; /* MAC buffer id for info frame */
        /* txfid, intransmitfid, next_txtid, and next_alloc are protected by