[PATCH next v3 02/15] mtd: mtdoops: synchronize kmsg_dumper

[Petr Mladek]

On Thu 2021-02-25 21:24:25, John Ogness wrote:
> The kmsg_dumper can be called from any context and CPU, possibly
> from multiple CPUs simultaneously. Since the writing of the buffer
> can occur from a later scheduled work queue, the oops buffer must
> be protected against simultaneous dumping.
> 
> Use an atomic bit to mark when the buffer is protected. Release the
> protection in between setting the buffer and the actual writing in
> order for a possible panic (immediate write) to be written during
> the scheduling of a previous oops (delayed write).

Just to be sure. You did not use spin lock to prevent problems
with eventual double unlock in panic(). Do I get it correctly,
please?

> Signed-off-by: John Ogness <john.ogness at linutronix.de>

Anyway, it looks good to me.

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

Best Regards,
Petr