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authorJiri Slaby <jslaby@suse.cz>2012-06-04 13:35:27 +0200
committerRichard Weinberger <richard@nod.at>2012-07-28 17:47:58 +0200
commit6fc58845ad189f8ceebd68a2ff524bfcd689a75e (patch)
tree7acc1ed13ec6427bf80f9ef3bf6eb4be0119663d /arch/um
parentTTY: um/line, add tty_port (diff)
downloadlinux-dev-6fc58845ad189f8ceebd68a2ff524bfcd689a75e.tar.xz
linux-dev-6fc58845ad189f8ceebd68a2ff524bfcd689a75e.zip
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>
Diffstat (limited to 'arch/um')
-rw-r--r--arch/um/drivers/chan_kern.c4
-rw-r--r--arch/um/drivers/line.c25
-rw-r--r--arch/um/drivers/line.h1
3 files changed, 21 insertions, 9 deletions
diff --git a/arch/um/drivers/chan_kern.c b/arch/um/drivers/chan_kern.c
index 45e248c2f43c..87eebfe03c61 100644
--- a/arch/um/drivers/chan_kern.c
+++ b/arch/um/drivers/chan_kern.c
@@ -150,9 +150,11 @@ void chan_enable_winch(struct chan *chan, struct tty_struct *tty)
static void line_timer_cb(struct work_struct *work)
{
struct line *line = container_of(work, struct line, task.work);
+ struct tty_struct *tty = tty_port_tty_get(&line->port);
if (!line->throttled)
- chan_interrupt(line, line->tty, line->driver->read_irq);
+ chan_interrupt(line, tty, line->driver->read_irq);
+ tty_kref_put(tty);
}
int enable_chan(struct line *line)
diff --git a/arch/um/drivers/line.c b/arch/um/drivers/line.c
index 482a7bd4a64c..fb6e4ea09921 100644
--- a/arch/um/drivers/line.c
+++ b/arch/um/drivers/line.c
@@ -19,9 +19,11 @@ static irqreturn_t line_interrupt(int irq, void *data)
{
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 @@ static irqreturn_t line_write_interrupt(int irq, void *data)
{
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 @@ static irqreturn_t line_write_interrupt(int irq, void *data)
}
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 @@ int line_open(struct line *lines, struct tty_struct *tty)
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 @@ void line_close(struct tty_struct *tty, struct file * filp)
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 @@ int line_get_config(char *name, struct line *lines, unsigned int num, char *str,
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;
diff --git a/arch/um/drivers/line.h b/arch/um/drivers/line.h
index 0e06a1f441d7..5b3d4fbdec18 100644
--- a/arch/um/drivers/line.h
+++ b/arch/um/drivers/line.h
@@ -33,7 +33,6 @@ struct line_driver {
struct line {
struct tty_port port;
- struct tty_struct *tty;
struct mutex count_lock;
int valid;