[PATCH] cfg80211: add missing device list locking

[PATCH] cfg80211: add missing device list locking

[Johannes Berg]

When calling into the wext code from the NETDEV_UP
notifier, we need to hold the devlist_mtx mutex as
the wext code ends up calling into channel checks.

Reported-by: Kalle Valo <kalle.valo@iki.fi>
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
---
 net/wireless/core.c |    2 ++
 1 file changed, 2 insertions(+)

--- wireless-testing.orig/net/wireless/core.c	2009-08-09 11:48:16.000000000 +0200
+++ wireless-testing/net/wireless/core.c	2009-08-09 11:48:32.000000000 +0200
@@ -710,6 +710,7 @@ static int cfg80211_netdev_notifier_call
 	case NETDEV_UP:
 #ifdef CONFIG_WIRELESS_EXT
 		cfg80211_lock_rdev(rdev);
+		mutex_lock(&rdev->devlist_mtx);
 		wdev_lock(wdev);
 		switch (wdev->iftype) {
 		case NL80211_IFTYPE_ADHOC:
@@ -722,6 +723,7 @@ static int cfg80211_netdev_notifier_call
 			break;
 		}
 		wdev_unlock(wdev);
+		mutex_unlock(&rdev->devlist_mtx);
 		cfg80211_unlock_rdev(rdev);
 #endif
 		break;

Re: [PATCH] cfg80211: add missing device list locking

[Kalle Valo]

Johannes Berg <johannes@sipsolutions.net> writes:

> When calling into the wext code from the NETDEV_UP
> notifier, we need to hold the devlist_mtx mutex as
> the wext code ends up calling into channel checks.
>
> Reported-by: Kalle Valo <kalle.valo@iki.fi>
> Signed-off-by: Johannes Berg <johannes@sipsolutions.net>

Thanks for fixing this. I wasn't able to reproduce the warning after one
suspend/resume cycle, but I'll test this patch a bit more before I send
my Tested-by tag.

-- 
Kalle Valo

Re: [PATCH] cfg80211: add missing device list locking

[Kalle Valo]

Johannes Berg <johannes@sipsolutions.net> writes:

> When calling into the wext code from the NETDEV_UP
> notifier, we need to hold the devlist_mtx mutex as
> the wext code ends up calling into channel checks.
>
> Reported-by: Kalle Valo <kalle.valo@iki.fi>
> Signed-off-by: Johannes Berg <johannes@sipsolutions.net>

I have been testing with patch for a day now and no warnings anymore.

Tested-by: Kalle Valo <kalle.valo@iki.fi>

-- 
Kalle Valo