Re: [PATCH linux-next] printk: nbcon: Fix nbcon_cpu_emergency_flush() when preemptible
From: Petr Mladek
Date: Wed Jun 05 2024 - 06:15:17 EST
On Wed 2024-06-05 12:10:50, Petr Mladek wrote:
> On Wed 2024-06-05 11:57:34, John Ogness wrote:
> > nbcon_cpu_emergency_flush() can be called in a preemptible
> > context. In that case the CPU is not in an emergency state.
> > However, in order to see that the CPU is not in an emergency
> > state (accessing the per-cpu variable), preemption must be
> > disabled.
> >
> > Disable preemption when checking the CPU state.
> >
> > Reported-by: Juri Lelli <juri.lelli@xxxxxxxxxx>
> > Closes: https://lore.kernel.org/aqkcpca4vgadxc3yzcu74xwq3grslj5m43f3eb5fcs23yo2gy4@gcsnqcts5tos
> > Fixes: 46a1379208b7 ("printk: nbcon: Implement emergency sections")
> > Signed-off-by: John Ogness <john.ogness@xxxxxxxxxxxxx>
>
> Great catch!
>
> Reviewed-by: Petr Mladek <pmladek@xxxxxxxx>
>
> I am going to push it...
Juri, should/could I add your Tested-by ?
Best Regards,
Petr