diff options
| author | Mike Galbraith <umgwanakikbuti@gmail.com> | 2016-10-16 05:11:54 +0200 |
|---|---|---|
| committer | Sebastian Andrzej Siewior <bigeasy@linutronix.de> | 2019-12-17 22:00:30 +0100 |
| commit | 78412101a22410944389c3bbc954ba97a0f47e0f (patch) | |
| tree | 4ca2a5875e1b4609c3a78b600689e36202960acf | |
| parent | 8c5f41c2e7734590a54b82a6329f19fb40f4db42 (diff) | |
| download | linux-rt-78412101a22410944389c3bbc954ba97a0f47e0f.tar.gz | |
connector/cn_proc: Protect send_msg() with a local lock on RT
|BUG: sleeping function called from invalid context at kernel/locking/rtmutex.c:931
|in_atomic(): 1, irqs_disabled(): 0, pid: 31807, name: sleep
|Preemption disabled at:[<ffffffff8148019b>] proc_exit_connector+0xbb/0x140
|
|CPU: 4 PID: 31807 Comm: sleep Tainted: G W E 4.8.0-rt11-rt #106
|Call Trace:
| [<ffffffff813436cd>] dump_stack+0x65/0x88
| [<ffffffff8109c425>] ___might_sleep+0xf5/0x180
| [<ffffffff816406b0>] __rt_spin_lock+0x20/0x50
| [<ffffffff81640978>] rt_read_lock+0x28/0x30
| [<ffffffff8156e209>] netlink_broadcast_filtered+0x49/0x3f0
| [<ffffffff81522621>] ? __kmalloc_reserve.isra.33+0x31/0x90
| [<ffffffff8156e5cd>] netlink_broadcast+0x1d/0x20
| [<ffffffff8147f57a>] cn_netlink_send_mult+0x19a/0x1f0
| [<ffffffff8147f5eb>] cn_netlink_send+0x1b/0x20
| [<ffffffff814801d8>] proc_exit_connector+0xf8/0x140
| [<ffffffff81077f71>] do_exit+0x5d1/0xba0
| [<ffffffff810785cc>] do_group_exit+0x4c/0xc0
| [<ffffffff81078654>] SyS_exit_group+0x14/0x20
| [<ffffffff81640a72>] entry_SYSCALL_64_fastpath+0x1a/0xa4
Since ab8ed951080e ("connector: fix out-of-order cn_proc netlink message
delivery") which is v4.7-rc6.
Signed-off-by: Mike Galbraith <umgwanakikbuti@gmail.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
| -rw-r--r-- | drivers/connector/cn_proc.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/drivers/connector/cn_proc.c b/drivers/connector/cn_proc.c index d58ce664da84..1b2e9f19c98d 100644 --- a/drivers/connector/cn_proc.c +++ b/drivers/connector/cn_proc.c @@ -18,6 +18,7 @@ #include <linux/pid_namespace.h> #include <linux/cn_proc.h> +#include <linux/locallock.h> /* * Size of a cn_msg followed by a proc_event structure. Since the @@ -40,10 +41,11 @@ static struct cb_id cn_proc_event_id = { CN_IDX_PROC, CN_VAL_PROC }; /* proc_event_counts is used as the sequence number of the netlink message */ static DEFINE_PER_CPU(__u32, proc_event_counts) = { 0 }; +static DEFINE_LOCAL_IRQ_LOCK(send_msg_lock); static inline void send_msg(struct cn_msg *msg) { - preempt_disable(); + local_lock(send_msg_lock); msg->seq = __this_cpu_inc_return(proc_event_counts) - 1; ((struct proc_event *)msg->data)->cpu = smp_processor_id(); @@ -56,7 +58,7 @@ static inline void send_msg(struct cn_msg *msg) */ cn_netlink_send(msg, 0, CN_IDX_PROC, GFP_NOWAIT); - preempt_enable(); + local_unlock(send_msg_lock); } void proc_fork_connector(struct task_struct *task) |