net: Add rtnl_lock_killable() (79ffdfc6) · Commits · 戴 / test

rtnl_lock() is widely used mutex in kernel. Some of kernel code does memory allocations under it. In case of memory deficit this may invoke OOM killer, but the problem is a killed task can't exit if it's waiting for the mutex. This may be a reason of deadlock and panic. This patch adds a new primitive, which responds on SIGKILL, and it allows to use it in the places, where we don't want to sleep forever. Signed-off-by:

Kirill Tkhai <ktkhai@virtuozzo.com> Signed-off-by:

David S. Miller <davem@davemloft.net>

include/linux/rtnetlink.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -33,6 +33,7 @@ extern void rtnl_lock(void);
		extern void rtnl_unlock(void);
		extern int rtnl_trylock(void);
		extern int rtnl_is_locked(void);
		extern int rtnl_lock_killable(void);

		extern wait_queue_head_t netdev_unregistering_wq;
		extern struct rw_semaphore net_sem;

net/core/rtnetlink.c

+6 −0

Original line number	Diff line number	Diff line
		@@ -75,6 +75,12 @@ void rtnl_lock(void)
		}
		EXPORT_SYMBOL(rtnl_lock);

		int rtnl_lock_killable(void)
		{
		return mutex_lock_killable(&rtnl_mutex);
		}
		EXPORT_SYMBOL(rtnl_lock_killable);

		static struct sk_buff *defer_kfree_skb_list;
		void rtnl_kfree_skbs(struct sk_buff head, struct sk_buff tail)
		{

Admin message