On Tue, Jul 7, 2020 at 12:49 AM Andy Shevchenko
<andriy.shevchenko@xxxxxxxxxxxxxxx> wrote:
>
> The comment near to uart_port_spin_lock_init() says:
>
> Ensure that the serial console lock is initialised early.
> If this port is a console, then the spinlock is already initialised.
>
> and there is nothing about enabled or disabled consoles. The commit
> a3cb39d258ef ("serial: core: Allow detach and attach serial device
> for console") made a change, which follows the comment, and also to
> prevent reinitialisation of the lock in use, when user detaches and
> attaches back the same console device. But this change discovers
> another issue, that uart_add_one_port() tries to access a spin lock
> that now may be uninitialised. This happens when a driver expects
> the serial core to register a console on its behalf. In this case
> we must initialise a spin lock before use.
>
> Fixes: a3cb39d258ef ("serial: core: Allow detach and attach serial device for console")
> Reported-by: Marc Zyngier <maz@xxxxxxxxxx>
> Reported-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx>
> Reported-by: Guenter Roeck <linux@xxxxxxxxxxxx>
> Reported-by: Anatoly Pugachev <matorola@xxxxxxxxx>
> Acked-by: Marc Zyngier <maz@xxxxxxxxxx>
> Tested-by: Tony Lindgren <tony@xxxxxxxxxxx>
> Cc: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
> ---
> v3: renamed lock init primitive and dropped inline (Marc), added tags (Marc, Tony)
> drivers/tty/serial/serial_core.c | 16 ++++++++++++++--
> 1 file changed, 14 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c
Andy,
probably late, but tested on my sparc64 ldom - works (boots).
Thanks.
