78 lines
3.0 KiB
Diff
78 lines
3.0 KiB
Diff
From 85d8de326e1ace824f3cc022f10d9f6079e032bd Mon Sep 17 00:00:00 2001
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Message-Id: <85d8de326e1ace824f3cc022f10d9f6079e032bd.1601675152.git.zanussi@kernel.org>
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In-Reply-To: <5b5a156f9808b1acf1205606e03da117214549ea.1601675151.git.zanussi@kernel.org>
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References: <5b5a156f9808b1acf1205606e03da117214549ea.1601675151.git.zanussi@kernel.org>
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From: Mike Galbraith <umgwanakikbuti@gmail.com>
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Date: Sun, 16 Oct 2016 05:11:54 +0200
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Subject: [PATCH 245/333] connector/cn_proc: Protect send_msg() with a local
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lock on RT
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Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.19/older/patches-4.19.148-rt64.tar.xz
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|BUG: sleeping function called from invalid context at kernel/locking/rtmutex.c:931
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|in_atomic(): 1, irqs_disabled(): 0, pid: 31807, name: sleep
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|Preemption disabled at:[<ffffffff8148019b>] proc_exit_connector+0xbb/0x140
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|CPU: 4 PID: 31807 Comm: sleep Tainted: G W E 4.8.0-rt11-rt #106
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|Call Trace:
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| [<ffffffff813436cd>] dump_stack+0x65/0x88
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| [<ffffffff8109c425>] ___might_sleep+0xf5/0x180
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| [<ffffffff816406b0>] __rt_spin_lock+0x20/0x50
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| [<ffffffff81640978>] rt_read_lock+0x28/0x30
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| [<ffffffff8156e209>] netlink_broadcast_filtered+0x49/0x3f0
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| [<ffffffff81522621>] ? __kmalloc_reserve.isra.33+0x31/0x90
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| [<ffffffff8156e5cd>] netlink_broadcast+0x1d/0x20
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| [<ffffffff8147f57a>] cn_netlink_send_mult+0x19a/0x1f0
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| [<ffffffff8147f5eb>] cn_netlink_send+0x1b/0x20
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| [<ffffffff814801d8>] proc_exit_connector+0xf8/0x140
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| [<ffffffff81077f71>] do_exit+0x5d1/0xba0
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| [<ffffffff810785cc>] do_group_exit+0x4c/0xc0
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| [<ffffffff81078654>] SyS_exit_group+0x14/0x20
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| [<ffffffff81640a72>] entry_SYSCALL_64_fastpath+0x1a/0xa4
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Since ab8ed951080e ("connector: fix out-of-order cn_proc netlink message
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delivery") which is v4.7-rc6.
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Signed-off-by: Mike Galbraith <umgwanakikbuti@gmail.com>
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Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
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---
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drivers/connector/cn_proc.c | 6 ++++--
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1 file changed, 4 insertions(+), 2 deletions(-)
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diff --git a/drivers/connector/cn_proc.c b/drivers/connector/cn_proc.c
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index ad48fd52cb53..c5264b3ee0b0 100644
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--- a/drivers/connector/cn_proc.c
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+++ b/drivers/connector/cn_proc.c
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@@ -32,6 +32,7 @@
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#include <linux/pid_namespace.h>
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#include <linux/cn_proc.h>
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+#include <linux/locallock.h>
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/*
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* Size of a cn_msg followed by a proc_event structure. Since the
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@@ -54,10 +55,11 @@ static struct cb_id cn_proc_event_id = { CN_IDX_PROC, CN_VAL_PROC };
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/* proc_event_counts is used as the sequence number of the netlink message */
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static DEFINE_PER_CPU(__u32, proc_event_counts) = { 0 };
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+static DEFINE_LOCAL_IRQ_LOCK(send_msg_lock);
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static inline void send_msg(struct cn_msg *msg)
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{
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- preempt_disable();
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+ local_lock(send_msg_lock);
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msg->seq = __this_cpu_inc_return(proc_event_counts) - 1;
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((struct proc_event *)msg->data)->cpu = smp_processor_id();
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@@ -70,7 +72,7 @@ static inline void send_msg(struct cn_msg *msg)
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*/
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cn_netlink_send(msg, 0, CN_IDX_PROC, GFP_NOWAIT);
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- preempt_enable();
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+ local_unlock(send_msg_lock);
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}
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void proc_fork_connector(struct task_struct *task)
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--
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2.17.1
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