summaryrefslogtreecommitdiffstats
path: root/debian/patches-rt/0296-printk-Enhance-the-condition-check-of-msleep-in-pr_f.patch
blob: 72589519a390cf9ac81d291b329007f24db9a5b0 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
From 6e1b154dfc59c96068eafef9fafbda28b723d3e6 Mon Sep 17 00:00:00 2001
From: Chao Qin <chao.qin@intel.com>
Date: Mon, 19 Jul 2021 10:26:50 +0800
Subject: [PATCH 296/323] printk: Enhance the condition check of msleep in
 pr_flush()
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/5.10/older/patches-5.10.204-rt100.tar.xz

[ Upstream commit 83e9288d9c4295d1195e9d780fcbc42c72ba4a83 ]

There is msleep in pr_flush(). If call WARN() in the early boot
stage such as in early_initcall, pr_flush() will run into msleep
when process scheduler is not ready yet. And then the system will
sleep forever.

Before the system_state is SYSTEM_RUNNING, make sure DO NOT sleep
in pr_flush().

Fixes: c0b395bd0fe3("printk: add pr_flush()")
Signed-off-by: Chao Qin <chao.qin@intel.com>
Signed-off-by: Lili Li <lili.li@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: John Ogness <john.ogness@linutronix.de>
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/lkml/20210719022649.3444072-1-chao.qin@intel.com
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
 kernel/printk/printk.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index 14cb111fe9f0..d2205872304d 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -3554,7 +3554,9 @@ bool pr_flush(int timeout_ms, bool reset_on_progress)
 	u64 diff;
 	u64 seq;
 
-	may_sleep = (preemptible() && !in_softirq());
+	may_sleep = (preemptible() &&
+		     !in_softirq() &&
+		     system_state >= SYSTEM_RUNNING);
 
 	seq = prb_next_seq(prb);
 
-- 
2.43.0