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| author | Kirill Tkhai <ktkhai@virtuozzo.com> | 2018-03-14 22:17:20 +0300 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2018-03-16 19:31:19 +0300 |
| commit | 79ffdfc6522ae33d8a33e971070c08ee5f27439b (patch) | |
| tree | 415425dcf355385d0847a857c0f03094604668cc | |
| parent | 320bd6de79ef0de1ece7c184469a722de690ccb0 (diff) | |
| download | linux-79ffdfc6522ae33d8a33e971070c08ee5f27439b.tar.xz | |
net: Add rtnl_lock_killable()
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>
| -rw-r--r-- | include/linux/rtnetlink.h | 1 | ||||
| -rw-r--r-- | net/core/rtnetlink.c | 6 |
2 files changed, 7 insertions, 0 deletions
diff --git a/include/linux/rtnetlink.h b/include/linux/rtnetlink.h index 3573b4bf2fdf..562a175c35a9 100644 --- a/include/linux/rtnetlink.h +++ b/include/linux/rtnetlink.h @@ -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; diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c index 67f375cfb982..87079eaa871b 100644 --- a/net/core/rtnetlink.c +++ b/net/core/rtnetlink.c @@ -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) { |