From 95f4d5f01bb56b4f940c8b44be8e71c5f35f2069 Mon Sep 17 00:00:00 2001 From: Jiri Slaby Date: Mon, 4 Jun 2012 13:35:27 +0200 Subject: [PATCH] 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 Cc: Jeff Dike Cc: Richard Weinberger Cc: user-mode-linux-devel@lists.sourceforge.net Signed-off-by: Greg Kroah-Hartman --- arch/um/drivers/chan_kern.c | 4 +++- arch/um/drivers/line.c | 25 ++++++++++++++++++------- arch/um/drivers/line.h | 1 - 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;