tty: hvcs: Don't NULL tty->driver_data until hvcs_cleanup()
[ Upstream commit5.4-rM2-2.2.x-imx-squashed63ffcbdad7
] The code currently NULLs tty->driver_data in hvcs_close() with the intent of informing the next call to hvcs_open() that device needs to be reconfigured. However, when hvcs_cleanup() is called we copy hvcsd from tty->driver_data which was previoulsy NULLed by hvcs_close() and our call to tty_port_put(&hvcsd->port) doesn't actually do anything since &hvcsd->port ends up translating to NULL by chance. This has the side effect that when hvcs_remove() is called we have one too many port references preventing hvcs_destuct_port() from ever being called. This also prevents us from reusing the /dev/hvcsX node in a future hvcs_probe() and we can eventually run out of /dev/hvcsX devices. Fix this by waiting to NULL tty->driver_data in hvcs_cleanup(). Fixes:27bf7c43a1
("TTY: hvcs, add tty install") Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com> Link: https://lore.kernel.org/r/20200820234643.70412-1-tyreld@linux.ibm.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
parent
f3f79d92ca
commit
bf94a8754f
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@ -1218,13 +1218,6 @@ static void hvcs_close(struct tty_struct *tty, struct file *filp)
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tty_wait_until_sent(tty, HVCS_CLOSE_WAIT);
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tty_wait_until_sent(tty, HVCS_CLOSE_WAIT);
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/*
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* This line is important because it tells hvcs_open that this
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* device needs to be re-configured the next time hvcs_open is
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* called.
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*/
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tty->driver_data = NULL;
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free_irq(irq, hvcsd);
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free_irq(irq, hvcsd);
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return;
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return;
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} else if (hvcsd->port.count < 0) {
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} else if (hvcsd->port.count < 0) {
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@ -1239,6 +1232,13 @@ static void hvcs_cleanup(struct tty_struct * tty)
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{
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{
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struct hvcs_struct *hvcsd = tty->driver_data;
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struct hvcs_struct *hvcsd = tty->driver_data;
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/*
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* This line is important because it tells hvcs_open that this
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* device needs to be re-configured the next time hvcs_open is
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* called.
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*/
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tty->driver_data = NULL;
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tty_port_put(&hvcsd->port);
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tty_port_put(&hvcsd->port);
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}
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}
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