TTY: um/line, use tty from tty_port
This means switching to the tty refcounted model so that we will not
race with interrupts.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: user-mode-linux-devel@lists.sourceforge.net
Signed-off-by: Richard Weinberger <richard@nod.at>
diff --git a/arch/um/drivers/line.c b/arch/um/drivers/line.c
index 482a7bd..fb6e4ea 100644
--- a/arch/um/drivers/line.c
+++ b/arch/um/drivers/line.c
@@ -19,9 +19,11 @@
{
struct chan *chan = data;
struct line *line = chan->line;
+ struct tty_struct *tty = tty_port_tty_get(&line->port);
if (line)
- chan_interrupt(line, line->tty, irq);
+ chan_interrupt(line, tty, irq);
+ tty_kref_put(tty);
return IRQ_HANDLED;
}
@@ -333,7 +335,7 @@
{
struct chan *chan = data;
struct line *line = chan->line;
- struct tty_struct *tty = line->tty;
+ struct tty_struct *tty;
int err;
/*
@@ -352,10 +354,13 @@
}
spin_unlock(&line->lock);
+ tty = tty_port_tty_get(&line->port);
if (tty == NULL)
return IRQ_NONE;
tty_wakeup(tty);
+ tty_kref_put(tty);
+
return IRQ_HANDLED;
}
@@ -409,7 +414,7 @@
BUG_ON(tty->driver_data);
tty->driver_data = line;
- line->tty = tty;
+ tty_port_tty_set(&line->port, tty);
err = enable_chan(line);
if (err) /* line_close() will be called by our caller */
@@ -449,7 +454,7 @@
if (--line->port.count)
goto out_unlock;
- line->tty = NULL;
+ tty_port_tty_set(&line->port, NULL);
tty->driver_data = NULL;
if (line->sigio) {
@@ -610,9 +615,15 @@
mutex_lock(&line->count_lock);
if (!line->valid)
CONFIG_CHUNK(str, size, n, "none", 1);
- else if (line->tty == NULL)
- CONFIG_CHUNK(str, size, n, line->init_str, 1);
- else n = chan_config_string(line, str, size, error_out);
+ else {
+ struct tty_struct *tty = tty_port_tty_get(&line->port);
+ if (tty == NULL) {
+ CONFIG_CHUNK(str, size, n, line->init_str, 1);
+ } else {
+ n = chan_config_string(line, str, size, error_out);
+ tty_kref_put(tty);
+ }
+ }
mutex_unlock(&line->count_lock);
return n;