From: Alan Jenkins <alan-jenkins@tuffmail.co.uk>
Date: Wed, 29 Apr 2009 10:41:24 +0000 (+0100)
Subject: mac80211: fix modprobe deadlock by not calling wep_init under rtnl_lock
X-Git-Tag: v2.6.30-rc6~2^2~40^2~1
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=d4c4a9a1bce1912ed5681251f0037fd4f2364a3e;p=profile%2Fivi%2Fkernel-x86-ivi.git

mac80211: fix modprobe deadlock by not calling wep_init under rtnl_lock

- ieee80211_wep_init(), which is called with rtnl_lock held, blocks in
   request_module() [waiting for modprobe to load a crypto module].

 - modprobe blocks in a call to flush_workqueue(), when it closes a TTY
   [presumably when it exits].

 - The workqueue item linkwatch_event() blocks on rtnl_lock.

There's no reason for wep_init() to be called with rtnl_lock held, so
just move it outside the critical section.

Signed-off-by: Alan Jenkins <alan-jenkins@tuffmail.co.uk>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
---

diff --git a/net/mac80211/main.c b/net/mac80211/main.c
index fbcbed6..00968c2 100644
--- a/net/mac80211/main.c
+++ b/net/mac80211/main.c
@@ -909,6 +909,13 @@ int ieee80211_register_hw(struct ieee80211_hw *hw)
 	if (result < 0)
 		goto fail_sta_info;
 
+	result = ieee80211_wep_init(local);
+	if (result < 0) {
+		printk(KERN_DEBUG "%s: Failed to initialize wep: %d\n",
+		       wiphy_name(local->hw.wiphy), result);
+		goto fail_wep;
+	}
+
 	rtnl_lock();
 	result = dev_alloc_name(local->mdev, local->mdev->name);
 	if (result < 0)
@@ -930,14 +937,6 @@ int ieee80211_register_hw(struct ieee80211_hw *hw)
 		goto fail_rate;
 	}
 
-	result = ieee80211_wep_init(local);
-
-	if (result < 0) {
-		printk(KERN_DEBUG "%s: Failed to initialize wep: %d\n",
-		       wiphy_name(local->hw.wiphy), result);
-		goto fail_wep;
-	}
-
 	/* add one default STA interface if supported */
 	if (local->hw.wiphy->interface_modes & BIT(NL80211_IFTYPE_STATION)) {
 		result = ieee80211_if_add(local, "wlan%d", NULL,
@@ -967,13 +966,13 @@ int ieee80211_register_hw(struct ieee80211_hw *hw)
 
 	return 0;
 
-fail_wep:
-	rate_control_deinitialize(local);
 fail_rate:
 	unregister_netdevice(local->mdev);
 	local->mdev = NULL;
 fail_dev:
 	rtnl_unlock();
+	ieee80211_wep_free(local);
+fail_wep:
 	sta_info_stop(local);
 fail_sta_info:
 	debugfs_hw_del(local);