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| author | Tyrel Datwyler <tyreld@linux.ibm.com> | 2020-08-20 18:46:38 -0500 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-10-29 09:55:08 +0100 |
| commit | 51ba64f0b37b2944758ae77d71ee099983ee930a (patch) | |
| tree | 006590eb74609466d8791a55b86c14771bb79eb3 /drivers | |
| parent | 2ee8f08ff33bf98896bcf46089f7ae7b45b30b32 (diff) | |
| download | linux-stable-51ba64f0b37b2944758ae77d71ee099983ee930a.tar.gz linux-stable-51ba64f0b37b2944758ae77d71ee099983ee930a.tar.bz2 linux-stable-51ba64f0b37b2944758ae77d71ee099983ee930a.zip | |
tty: hvcs: Don't NULL tty->driver_data until hvcs_cleanup()
[ Upstream commit 63ffcbdad738e3d1c857027789a2273df3337624 ]
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: 27bf7c43a19c ("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>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/tty/hvc/hvcs.c | 14 |
1 files changed, 7 insertions, 7 deletions
diff --git a/drivers/tty/hvc/hvcs.c b/drivers/tty/hvc/hvcs.c index cb4db1b3ca3c..7853c6375325 100644 --- a/drivers/tty/hvc/hvcs.c +++ b/drivers/tty/hvc/hvcs.c @@ -1218,13 +1218,6 @@ static void hvcs_close(struct tty_struct *tty, struct file *filp) tty_wait_until_sent(tty, HVCS_CLOSE_WAIT); - /* - * This line is important because it tells hvcs_open that this - * device needs to be re-configured the next time hvcs_open is - * called. - */ - tty->driver_data = NULL; - free_irq(irq, hvcsd); return; } else if (hvcsd->port.count < 0) { @@ -1239,6 +1232,13 @@ static void hvcs_cleanup(struct tty_struct * tty) { struct hvcs_struct *hvcsd = tty->driver_data; + /* + * This line is important because it tells hvcs_open that this + * device needs to be re-configured the next time hvcs_open is + * called. + */ + tty->driver_data = NULL; + tty_port_put(&hvcsd->port); } |