mac80211: fix deadlocks in debugfs_netdev.c
The bug shows up with CONFIG_PREEMPT enabled. Pointed out by Andrew Morton.
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Luis Carlos Cobo <luisca@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/net/mac80211/debugfs_netdev.c b/net/mac80211/debugfs_netdev.c
index 0e921ae..3e19d42 100644
--- a/net/mac80211/debugfs_netdev.c
+++ b/net/mac80211/debugfs_netdev.c
@@ -31,11 +31,13 @@
ssize_t ret = -EINVAL;
read_lock(&dev_base_lock);
- if (sdata->dev->reg_state == NETREG_REGISTERED) {
+ if (sdata->dev->reg_state == NETREG_REGISTERED)
ret = (*format)(sdata, buf, sizeof(buf));
- ret = simple_read_from_buffer(userbuf, count, ppos, buf, ret);
- }
read_unlock(&dev_base_lock);
+
+ if (ret != -EINVAL)
+ ret = simple_read_from_buffer(userbuf, count, ppos, buf, ret);
+
return ret;
}
@@ -51,13 +53,13 @@
memset(buf, 0x00, sizeof(buf));
buf_size = min(count, (sizeof(buf)-1));
- read_lock(&dev_base_lock);
if (copy_from_user(buf, userbuf, buf_size))
- goto endwrite;
+ return count;
+ read_lock(&dev_base_lock);
if (sdata->dev->reg_state == NETREG_REGISTERED)
(*format)(sdata, buf);
-endwrite:
read_unlock(&dev_base_lock);
+
return count;
}
#endif