releases/2.6.33.7/hostap-protect-against-initialization-interrupt.patch

From d6a574ff6bfb842bdb98065da053881ff527be46 Mon Sep 17 00:00:00 2001
From: Tim Gardner <tim.gardner@canonical.com>
Date: Tue, 8 Jun 2010 11:33:02 -0600
Subject: hostap: Protect against initialization interrupt

From: Tim Gardner <tim.gardner@canonical.com>

commit d6a574ff6bfb842bdb98065da053881ff527be46 upstream.

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>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
 drivers/net/wireless/hostap/hostap_cs.c   |   15 +++++++++++++--
 drivers/net/wireless/hostap/hostap_hw.c   |   13 +++++++++++++
 drivers/net/wireless/hostap/hostap_wlan.h |    2 +-
 3 files changed, 27 insertions(+), 3 deletions(-)

--- a/drivers/net/wireless/hostap/hostap_cs.c
+++ b/drivers/net/wireless/hostap/hostap_cs.c
@@ -602,6 +602,7 @@ static int prism2_config(struct pcmcia_d
 	local_info_t *local;
 	int ret = 1;
 	struct hostap_cs_priv *hw_priv;
+	unsigned long flags;
 
 	PDEBUG(DEBUG_FLOW, "prism2_config()\n");
 
@@ -636,6 +637,12 @@ static int prism2_config(struct pcmcia_d
 	link->dev_node = &hw_priv->node;
 
 	/*
+	 * Make sure the IRQ handler cannot proceed until at least
+	 * dev->base_addr is initialized.
+	 */
+	spin_lock_irqsave(&local->irq_init_lock, flags);
+
+	/*
 	 * Allocate an interrupt line.  Note that this does not assign a
 	 * handler to the interrupt, unless the 'Handler' member of the
 	 * irq structure is initialized.
@@ -645,7 +652,7 @@ static int prism2_config(struct pcmcia_d
 		link->irq.Handler = prism2_interrupt;
 		ret = pcmcia_request_irq(link, &link->irq);
 		if (ret)
-			goto failed;
+			goto failed_unlock;
 	}
 
 	/*
@@ -655,11 +662,13 @@ static int prism2_config(struct pcmcia_d
 	 */
 	ret = pcmcia_request_configuration(link, &link->conf);
 	if (ret)
-		goto failed;
+		goto failed_unlock;
 
 	dev->irq = link->irq.AssignedIRQ;
 	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);
@@ -688,6 +697,8 @@ static int prism2_config(struct pcmcia_d
 	}
 	return ret;
 
+ failed_unlock:
+	 spin_unlock_irqrestore(&local->irq_init_lock, flags);
  failed:
 	kfree(hw_priv);
 	prism2_release((u_long)link);
--- 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
 	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_hel
 	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)
--- 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