Re: [PATCH printk v4 14/14] dump_stack: Do not get cpu_sync for panic CPU

Petr Mladek
2024-02-07T16:16:22Z

On Wed 2024-02-07 14:47:03, John Ogness wrote:
> dump_stack() is called in panic(). If for some reason another CPU
> is holding the printk_cpu_sync and is unable to release it, the
> panic CPU will be unable to continue and print the stacktrace.
>
> Since non-panic CPUs are not allowed to store new printk messages
> anyway, there is no need to synchronize the stacktrace output in
> a panic situation.
>
> For the panic CPU, do not get the printk_cpu_sync because it is
> not needed and avoids a potential deadlock scenario in panic().
>
> Link: https://lore.kernel.org/lkml/ZcIGKU8sxti38Kok@alley
> Signed-off-by: John Ogness <john.ogness@linutronix.de>

Makes sense.

Reviewed-by: Petr Mladek <pmladek@suse.com>

Best Regards,
Petr