Re: [PATCH linux-next] printk: nbcon: Fix nbcon_cpu_emergency_flush() when preemptible

[Petr Mladek]

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>

JFYI, the patch has been comitted into printk/linux.git,
branch rework/write-atomic.

Best Regards,
Petr