Messages in this thread | | | From | John Ogness <> | Subject | Re: [PREEMPT_RT][PATCH] printk: Enhance the condition check of msleep in pr_flush() | Date | Mon, 19 Jul 2021 17:01:51 +0206 |
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On 2021-07-19, chao.qin@intel.com wrote: > From: Chao Qin <chao.qin@intel.com> > > 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: 63cf1e4b564a ("printk: add pr_flush()") > > Signed-off-by: Chao Qin <chao.qin@intel.com> > Signed-off-by: Lili Li <lili.li@intel.com>
Reviewed-by: John Ogness <john.ogness@linutronix.de>
> --- > kernel/printk/printk.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c > index 209d2392f0d8..a9b3afbdac39 100644 > --- a/kernel/printk/printk.c > +++ b/kernel/printk/printk.c > @@ -3620,7 +3620,8 @@ 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); > > > base-commit: 7e175e6b59975c8901ad370f7818937f68de45c1 > -- > 2.25.1
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