| From b4db337a8c0a69f0acee4fcca6c4ae5db725fe11 Mon Sep 17 00:00:00 2001 |
| From: Marcin Jurkowski <marcin1j@gmail.com> |
| Date: Sat, 2 Mar 2013 14:50:15 +0100 |
| Subject: [PATCH] w1: fix oops when w1_search is called from netlink connector |
| |
| commit 9d1817cab2f030f6af360e961cc69bb1da8ad765 upstream. |
| |
| 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 <kaber@trash.net> |
| > 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 <marcin1j@gmail.com> |
| Acked-by: Evgeniy Polyakov <zbr@ioremap.net> |
| Cc: Josh Boyer <jwboyer@gmail.com> |
| Tested-by: Sven Geggus <lists@fuchsschwanzdomain.de> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> |
| --- |
| drivers/w1/w1.c | 3 ++- |
| 1 file changed, 2 insertions(+), 1 deletion(-) |
| |
| diff --git a/drivers/w1/w1.c b/drivers/w1/w1.c |
| index ad5897dc4495..cf05f4c82baa 100644 |
| --- a/drivers/w1/w1.c |
| +++ b/drivers/w1/w1.c |
| @@ -918,7 +918,8 @@ 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()) { |
| dev_dbg(&dev->dev, "Abort w1_search\n"); |
| return; |
| } |
| -- |
| 1.8.5.2 |
| |
