Messages in this thread Patch in this message | | | Date | Fri, 06 Aug 2021 18:47:24 -0400 | From | Steven Rostedt <> | Subject | [PATCH RT 1/2] printk: Enhance the condition check of msleep in pr_flush() |
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5.10.56-rt49-rc1 stable review patch. If anyone has any objections, please let me know.
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From: Chao Qin <chao.qin@intel.com>
[ 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 f56fd2e34cc7..53d90278494b 100644 --- a/kernel/printk/printk.c +++ b/kernel/printk/printk.c @@ -3545,7 +3545,9 @@ 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); -- 2.30.2
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