A number of drivers (recently including cfg80211-based ones) assume that all wireless handlers, including statistics, can sleep and they often also implicitly assume that the rtnl is held around their invocation. This is almost always true now except when reading from sysfs: BUG: sleeping function called from invalid context at kernel/mutex.c:280 in_atomic(): 1, irqs_disabled(): 0, pid: 10450, name: head 2 locks held by head/10450: #0: (&buffer->mutex){+.+.+.}, at: [<c10ceb99>] sysfs_read_file+0x24/0xf4 #1: (dev_base_lock){++.?..}, at: [<c12844ee>] wireless_show+0x1a/0x4c Pid: 10450, comm: head Not tainted 2.6.32-rc3 #1 Call Trace: [<c102301c>] __might_sleep+0xf0/0xf7 [<c1324355>] mutex_lock_nested+0x1a/0x33 [<f8cea53b>] wdev_lock+0xd/0xf [cfg80211] [<f8cea58f>] cfg80211_wireless_stats+0x45/0x12d [cfg80211] [<c13118d6>] get_wireless_stats+0x16/0x1c [<c12844fe>] wireless_show+0x2a/0x4c Fix this by using the rtnl instead of dev_base_lock. Reported-by: Miles Lane <miles.lane@xxxxxxxxx> Signed-off-by: Johannes Berg <johannes@xxxxxxxxxxxxxxxx> --- net/core/net-sysfs.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- wireless-testing.orig/net/core/net-sysfs.c 2009-10-05 11:09:56.000000000 +0200 +++ wireless-testing/net/core/net-sysfs.c 2009-10-05 11:10:52.000000000 +0200 @@ -366,13 +366,13 @@ static ssize_t wireless_show(struct devi const struct iw_statistics *iw; ssize_t ret = -EINVAL; - read_lock(&dev_base_lock); + rtnl_lock(); if (dev_isalive(dev)) { iw = get_wireless_stats(dev); if (iw) ret = (*format)(iw, buf); } - read_unlock(&dev_base_lock); + rtnl_unlock(); return ret; } -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html