From: Marcin Jurkowski Date: Sat, 2 Mar 2013 13:50:15 +0000 (+0100) Subject: w1: fix oops when w1_search is called from netlink connector X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=9d1817cab2f030;p=linux-beck.git w1: fix oops when w1_search is called from netlink connector On Sat, Mar 02, 2013 at 10:45:10AM +0100, Sven Geggus wrote: > This is the bad commit I found doing git bisect: > 04f482faf50535229a5a5c8d629cf963899f857c is the first bad commit > commit 04f482faf50535229a5a5c8d629cf963899f857c > Author: Patrick McHardy > Date: Mon Mar 28 08:39:36 2011 +0000 Good job. I was too lazy to bisect for bad commit;) Reading the code I found problematic kthread_should_stop call from netlink connector which causes the oops. After applying a patch, I've been testing owfs+w1 setup for nearly two days and it seems to work very reliable (no hangs, no memleaks etc). More detailed description and possible fix is given below: Function w1_search can be called from either kthread or netlink callback. While the former works fine, the latter causes oops due to kthread_should_stop invocation. This patch adds a check if w1_search is serving netlink command, skipping kthread_should_stop invocation if so. Signed-off-by: Marcin Jurkowski Acked-by: Evgeniy Polyakov Cc: Josh Boyer Tested-by: Sven Geggus Signed-off-by: Greg Kroah-Hartman Cc: stable # 3.0+ --- diff --git a/drivers/w1/w1.c b/drivers/w1/w1.c index 7994d933f040..7ce277d2bb67 100644 --- a/drivers/w1/w1.c +++ b/drivers/w1/w1.c @@ -924,7 +924,8 @@ void w1_search(struct w1_master *dev, u8 search_type, w1_slave_found_callback cb tmp64 = (triplet_ret >> 2); rn |= (tmp64 << i); - if (kthread_should_stop()) { + /* ensure we're called from kthread and not by netlink callback */ + if (!dev->priv && kthread_should_stop()) { mutex_unlock(&dev->bus_mutex); dev_dbg(&dev->dev, "Abort w1_search\n"); return;