[ 05/98] netconsole: dont call __netpoll_cleanup() while atomic

Greg Kroah-Hartman
2013-03-26T23:50:04Z

From: Veaceslav Falico <vfalico@redhat.com>

[ Upstream commit 3f315bef23075ea8a98a6fe4221a83b83456d970 ]

__netpoll_cleanup() is called in netconsole_netdev_event() while holding a
spinlock. Release/acquire the spinlock before/after it and restart the
loop. Also, disable the netconsole completely, because we won't have chance
after the restart of the loop, and might end up in a situation where
nt->enabled == 1 and nt->np.dev == NULL.

Signed-off-by: Veaceslav Falico <vfalico@redhat.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/net/netconsole.c | 15 +++++++++------
1 file changed, 9 insertions(+), 6 deletions(-)

--- a/drivers/net/netconsole.c
+++ b/drivers/net/netconsole.c
@@ -630,6 +630,7 @@ static int netconsole_netdev_event(struc
goto done;

spin_lock_irqsave(&target_list_lock, flags);
+restart:
list_for_each_entry(nt, &target_list, list) {
netconsole_target_get(nt);
if (nt->np.dev == dev) {
@@ -642,15 +643,17 @@ static int netconsole_netdev_event(struc
case NETDEV_UNREGISTER:
/*
* rtnl_lock already held
+ * we might sleep in __netpoll_cleanup()
*/
- if (nt->np.dev) {
- __netpoll_cleanup(&nt->np);
- dev_put(nt->np.dev);
- nt->np.dev = NULL;
- }
+ spin_unlock_irqrestore(&target_list_lock, flags);
+ __netpoll_cleanup(&nt->np);
+ spin_lock_irqsave(&target_list_lock, flags);
+ dev_put(nt->np.dev);
+ nt->np.dev = NULL;
nt->enabled = 0;
stopped = true;
- break;
+ netconsole_target_put(nt);
+ goto restart;
}
}
netconsole_target_put(nt);