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-rw-r--r--debian/patches-rt/0245-connector-cn_proc-Protect-send_msg-with-a-local-lock.patch74
1 files changed, 74 insertions, 0 deletions
diff --git a/debian/patches-rt/0245-connector-cn_proc-Protect-send_msg-with-a-local-lock.patch b/debian/patches-rt/0245-connector-cn_proc-Protect-send_msg-with-a-local-lock.patch
new file mode 100644
index 000000000..8ce25e4b2
--- /dev/null
+++ b/debian/patches-rt/0245-connector-cn_proc-Protect-send_msg-with-a-local-lock.patch
@@ -0,0 +1,74 @@
+From 2d5d86f2a24500c2b02576c9d5de36bb90e86f10 Mon Sep 17 00:00:00 2001
+From: Mike Galbraith <umgwanakikbuti@gmail.com>
+Date: Sun, 16 Oct 2016 05:11:54 +0200
+Subject: [PATCH 245/347] connector/cn_proc: Protect send_msg() with a local
+ lock on RT
+Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.19/older/patches-4.19.246-rt110.tar.xz
+
+|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>
+---
+ drivers/connector/cn_proc.c | 6 ++++--
+ 1 file changed, 4 insertions(+), 2 deletions(-)
+
+diff --git a/drivers/connector/cn_proc.c b/drivers/connector/cn_proc.c
+index ad48fd52cb53..c5264b3ee0b0 100644
+--- a/drivers/connector/cn_proc.c
++++ b/drivers/connector/cn_proc.c
+@@ -32,6 +32,7 @@
+ #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
+@@ -54,10 +55,11 @@ 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();
+@@ -70,7 +72,7 @@ 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)
+--
+2.36.1
+