Re: [patch] drivers,connector: Protect send_msg() with a local lock for RT
On 2016-10-16 05:11:54 [+0200], Mike Galbraith wrote: > applied with smaller changes. This is v4.8-RT only. Sebastian
Re: [patch] drivers,connector: Protect send_msg() with a local lock for RT
On 2016-10-16 05:11:54 [+0200], Mike Galbraith wrote: > applied with smaller changes. This is v4.8-RT only. Sebastian
[patch] drivers,connector: Protect send_msg() with a local lock for RT
[ 6496.323071] BUG: sleeping function called from invalid context at kernel/locking/rtmutex.c:931 [ 6496.323072] in_atomic(): 1, irqs_disabled(): 0, pid: 31807, name: sleep [ 6496.323077] Preemption disabled at:[] proc_exit_connector+0xbb/0x140 [ 6496.323077] [ 6496.323080] CPU: 4 PID: 31807 Comm: sleep Tainted: GW E 4.8.0-rt11-rt #106 [ 6496.323081] Hardware name: IBM System x3550 M3 -[7944K3G]-/69Y5698 , BIOS -[D6E150AUS-1.10]- 12/15/2010 [ 6496.323084] 8801051d3d08 813436cd [ 6496.323086] 880167ccab80 8801051d3d28 8109c425 81ce91c0 [ 6496.323088] 8801051d3d40 816406b0 81ce91c0 [ 6496.323089] Call Trace: [ 6496.323092] [] dump_stack+0x65/0x88 [ 6496.323094] [] ___might_sleep+0xf5/0x180 [ 6496.323097] [] __rt_spin_lock+0x20/0x50 [ 6496.323100] [] rt_read_lock+0x28/0x30 [ 6496.323103] [] netlink_broadcast_filtered+0x49/0x3f0 [ 6496.323106] [] ? __kmalloc_reserve.isra.33+0x31/0x90 [ 6496.323109] [] netlink_broadcast+0x1d/0x20 [ 6496.323111] [] cn_netlink_send_mult+0x19a/0x1f0 [ 6496.323114] [] cn_netlink_send+0x1b/0x20 [ 6496.323116] [] proc_exit_connector+0xf8/0x140 [ 6496.323119] [] do_exit+0x5d1/0xba0 [ 6496.323122] [] do_group_exit+0x4c/0xc0 [ 6496.323125] [] SyS_exit_group+0x14/0x20 [ 6496.323127] [] entry_SYSCALL_64_fastpath+0x1a/0xa4 Signed-off-by: Mike Galbraith--- drivers/connector/cn_proc.c |7 +-- 1 file changed, 5 insertions(+), 2 deletions(-) --- a/drivers/connector/cn_proc.c +++ b/drivers/connector/cn_proc.c @@ -32,6 +32,7 @@ #include #include +#include /* * Size of a cn_msg followed by a proc_event structure. Since the @@ -54,10 +55,12 @@ static struct cb_id cn_proc_event_id = { /* 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(); + /* RT ordering protection, maps to preempt_disable() for !RT */ + local_lock(send_msg_lock); msg->seq = __this_cpu_inc_return(proc_event_counts) - 1; ((struct proc_event *)msg->data)->cpu = smp_processor_id(); @@ -70,7 +73,7 @@ static inline void send_msg(struct cn_ms */ 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)
[patch] drivers,connector: Protect send_msg() with a local lock for RT
[ 6496.323071] BUG: sleeping function called from invalid context at kernel/locking/rtmutex.c:931 [ 6496.323072] in_atomic(): 1, irqs_disabled(): 0, pid: 31807, name: sleep [ 6496.323077] Preemption disabled at:[] proc_exit_connector+0xbb/0x140 [ 6496.323077] [ 6496.323080] CPU: 4 PID: 31807 Comm: sleep Tainted: GW E 4.8.0-rt11-rt #106 [ 6496.323081] Hardware name: IBM System x3550 M3 -[7944K3G]-/69Y5698 , BIOS -[D6E150AUS-1.10]- 12/15/2010 [ 6496.323084] 8801051d3d08 813436cd [ 6496.323086] 880167ccab80 8801051d3d28 8109c425 81ce91c0 [ 6496.323088] 8801051d3d40 816406b0 81ce91c0 [ 6496.323089] Call Trace: [ 6496.323092] [] dump_stack+0x65/0x88 [ 6496.323094] [] ___might_sleep+0xf5/0x180 [ 6496.323097] [] __rt_spin_lock+0x20/0x50 [ 6496.323100] [] rt_read_lock+0x28/0x30 [ 6496.323103] [] netlink_broadcast_filtered+0x49/0x3f0 [ 6496.323106] [] ? __kmalloc_reserve.isra.33+0x31/0x90 [ 6496.323109] [] netlink_broadcast+0x1d/0x20 [ 6496.323111] [] cn_netlink_send_mult+0x19a/0x1f0 [ 6496.323114] [] cn_netlink_send+0x1b/0x20 [ 6496.323116] [] proc_exit_connector+0xf8/0x140 [ 6496.323119] [] do_exit+0x5d1/0xba0 [ 6496.323122] [] do_group_exit+0x4c/0xc0 [ 6496.323125] [] SyS_exit_group+0x14/0x20 [ 6496.323127] [] entry_SYSCALL_64_fastpath+0x1a/0xa4 Signed-off-by: Mike Galbraith --- drivers/connector/cn_proc.c |7 +-- 1 file changed, 5 insertions(+), 2 deletions(-) --- a/drivers/connector/cn_proc.c +++ b/drivers/connector/cn_proc.c @@ -32,6 +32,7 @@ #include #include +#include /* * Size of a cn_msg followed by a proc_event structure. Since the @@ -54,10 +55,12 @@ static struct cb_id cn_proc_event_id = { /* 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(); + /* RT ordering protection, maps to preempt_disable() for !RT */ + local_lock(send_msg_lock); msg->seq = __this_cpu_inc_return(proc_event_counts) - 1; ((struct proc_event *)msg->data)->cpu = smp_processor_id(); @@ -70,7 +73,7 @@ static inline void send_msg(struct cn_ms */ 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)