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TTY: introduce tty_port_destroy

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After commit "TTY: move tty buffers to tty_port", the tty buffers are
not freed in some drivers. This is because tty_port_destructor is not
called whenever a tty_port is freed. This was an assumption I counted
with but was unfortunately untrue.

Those using refcounting are safe now, but for those which do not we
introduce a function to be called right before the tty_port is freed
by the drivers.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Jiri Slaby 2012-11-15 09:49:54 +01:00 committed by Greg Kroah-Hartman
parent 9a8e62bc68
commit de274bfe0f
2 changed files with 16 additions and 1 deletions
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16
drivers/tty/tty_port.c
View File

@ -122,12 +122,26 @@ void tty_port_free_xmit_buf(struct tty_port *port)
} }
EXPORT_SYMBOL(tty_port_free_xmit_buf); EXPORT_SYMBOL(tty_port_free_xmit_buf);
/**
* tty_port_destroy -- destroy inited port
* @port: tty port to be doestroyed
*
* When a port was initialized using tty_port_init, one has to destroy the
* port by this function. Either indirectly by using tty_port refcounting
* (tty_port_put) or directly if refcounting is not used.
*/
void tty_port_destroy(struct tty_port *port)
{
tty_buffer_free_all(port);
}
EXPORT_SYMBOL(tty_port_destroy);
static void tty_port_destructor(struct kref *kref) static void tty_port_destructor(struct kref *kref)
{ {
struct tty_port *port = container_of(kref, struct tty_port, kref); struct tty_port *port = container_of(kref, struct tty_port, kref);
if (port->xmit_buf) if (port->xmit_buf)
free_page((unsigned long)port->xmit_buf); free_page((unsigned long)port->xmit_buf);
tty_buffer_free_all(port); tty_port_destroy(port);
if (port->ops && port->ops->destruct) if (port->ops && port->ops->destruct)
port->ops->destruct(port); port->ops->destruct(port);
else else

1
include/linux/tty.h
View File

@ -455,6 +455,7 @@ extern struct device *tty_port_register_device_attr(struct tty_port *port,
const struct attribute_group **attr_grp); const struct attribute_group **attr_grp);
extern int tty_port_alloc_xmit_buf(struct tty_port *port); extern int tty_port_alloc_xmit_buf(struct tty_port *port);
extern void tty_port_free_xmit_buf(struct tty_port *port); extern void tty_port_free_xmit_buf(struct tty_port *port);
extern void tty_port_destroy(struct tty_port *port);
extern void tty_port_put(struct tty_port *port); extern void tty_port_put(struct tty_port *port);
static inline struct tty_port *tty_port_get(struct tty_port *port) static inline struct tty_port *tty_port_get(struct tty_port *port)