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tty: serial_core: Fix serial console crash on port shutdown
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The port->console flag is always false, as uart_console() is called
before the serial console has been registered.

Hence for a serial port used as the console, uart_tty_port_shutdown()
will still be called when userspace closes the port, powering it down.
This may lead to a system lock up when the serial console driver writes
to the serial port's registers.

To fix this, move the setting of port->console after the call to
uart_configure_port(), which registers the serial console.

Fixes: 761ed4a ("tty: serial_core: convert uart_close to use tty_port_close")
Reported-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Rob Herring <robh@kernel.org>
Tested-by: Mugunthan V N <mugunthanvnm@ti.com>
Tested-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
[robh: rebased on tty-linus]
Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Geert Uytterhoeven authored and Greg Kroah-Hartman committed Oct 28, 2016
1 parent 9bcffe7 commit 4dda864
Showing 1 changed file with 2 additions and 0 deletions.
2 changes: 2 additions & 0 deletions drivers/tty/serial/serial_core.c
Original file line number Diff line number Diff line change
Expand Up @@ -2759,6 +2759,8 @@ int uart_add_one_port(struct uart_driver *drv, struct uart_port *uport)

uart_configure_port(drv, state, uport);

port->console = uart_console(uport);

num_groups = 2;
if (uport->attr_group)
num_groups++;
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