Commit 49bb3c86 authored by Andre Przywara's avatar Andre Przywara Committed by Greg Kroah-Hartman
Browse files

drivers: PL011: avoid potential unregister_driver call 



Although we care about not unregistering the driver if there are
still ports connected during the .remove callback, we do miss this
check in the pl011_probe function. So if the current port allocation
fails, but there are other ports already registered, we will kill
those.
So factor out the port removal into a separate function and use that
in the probe function, too.

Signed-off-by: default avatarAndre Przywara <andre.przywara@arm.com>
Tested-by: default avatarMark Langsdorf <mlangsdo@redhat.com>
Tested-by: default avatarNaresh Bhat <nbhat@cavium.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 7798edee

drivers/tty/serial/amba-pl011.c

+20 −16
Original line number Diff line number Diff line
@@ -2135,6 +2135,23 @@ static int pl011_probe_dt_alias(int index, struct device *dev) 
	return ret;

}



/* unregisters the driver also if no more ports are left */

static void pl011_unregister_port(struct uart_amba_port *uap)

{

	int i;

	bool busy = false;



	for (i = 0; i < ARRAY_SIZE(amba_ports); i++) {

		if (amba_ports[i] == uap)

			amba_ports[i] = NULL;

		else if (amba_ports[i])

			busy = true;

	}

	pl011_dma_remove(uap);

	if (!busy)

		uart_unregister_driver(&amba_reg);

}



static int pl011_probe(struct amba_device *dev, const struct amba_id *id)

{

	struct uart_amba_port *uap;
@@ -2200,10 +2217,8 @@ static int pl011_probe(struct amba_device *dev, const struct amba_id *id) 
	}



	ret = uart_add_one_port(&amba_reg, &uap->port);

	if (ret) {

		amba_ports[i] = NULL;

		uart_unregister_driver(&amba_reg);

	}

	if (ret)

		pl011_unregister_port(uap);



	return ret;

}
@@ -2211,20 +2226,9 @@ static int pl011_probe(struct amba_device *dev, const struct amba_id *id) 
static int pl011_remove(struct amba_device *dev)

{

	struct uart_amba_port *uap = amba_get_drvdata(dev);

	bool busy = false;

	int i;



	uart_remove_one_port(&amba_reg, &uap->port);



	for (i = 0; i < ARRAY_SIZE(amba_ports); i++)

		if (amba_ports[i] == uap)

			amba_ports[i] = NULL;

		else if (amba_ports[i])

			busy = true;



	pl011_dma_remove(uap);

	if (!busy)

		uart_unregister_driver(&amba_reg);

	pl011_unregister_port(uap);

	return 0;

}

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