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Commit f743061a authored by Andy Shevchenko's avatar Andy Shevchenko Committed by Greg Kroah-Hartman
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serial: core: Initialise spin lock before use in uart_configure_port()



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
a3cb39d2 ("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: a3cb39d2 ("serial: core: Allow detach and attach serial device for console")
Reported-by: default avatarMarc Zyngier <maz@kernel.org>
Reported-by: default avatarLad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reported-by: default avatarGuenter Roeck <linux@roeck-us.net>
Reported-by: default avatarAnatoly Pugachev <matorola@gmail.com>
Acked-by: default avatarMarc Zyngier <maz@kernel.org>
Tested-by: default avatarTony Lindgren <tony@atomide.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: default avatarAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: default avatarLad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Link: https://lore.kernel.org/r/20200706214903.56148-1-andriy.shevchenko@linux.intel.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent d8edf8eb
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