Re: [PATCH] context_tracking: Restore previous state in schedule_user

Dave Jones
2014-12-03T23:31:40Z

On Wed, Dec 03, 2014 at 03:18:41PM -0800, Andy Lutomirski wrote:
> It appears that some SCHEDULE_USER (asm for schedule_user) callers
> in arch/x86/kernel/entry_64.S are called from RCU kernel context,
> and schedule_user will return in RCU user context. This causes RCU
> warnings and possible failures.
>
> This is intended to be a minimal fix suitable for 3.18.
>
> Reported-by: Dave Jones <davej@redhat.com>
> Cc: Oleg Nesterov <oleg@redhat.com>
> Cc: Frédéric Weisbecker <fweisbec@gmail.com>
> Cc: Paul McKenney <paulmck@linux.vnet.ibm.com>
> Signed-off-by: Andy Lutomirski <luto@amacapital.net>
> ---
>
> Hi all-
>
> This is intended to be a suitable last-minute fix for the RCU issue that
> Dave saw.
>
> Dave, can you confirm that this fixes it?

ACK, feel free to add my Tested-by:

Dave