From 1ff2c873ca11f9e6abffb004b908756b27597672 Mon Sep 17 00:00:00 2001 From: Dmitry Torokhov Date: Mon, 16 May 2005 21:53:07 -0700 Subject: [PATCH] [PATCH] serport oops fix serport - avoid calling serio_interrupt or serio_write_wakeup on unregistered port. Also fix memory leak which could happen if serport was left unused by moving serio allocation down to serport_ldisc_read. Signed-off-by: Dmitry Torokhov Cc: Vojtech Pavlik Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/input/serio/serport.c | 100 +++++++++++++++++++++++----------- 1 file changed, 69 insertions(+), 31 deletions(-) diff --git a/drivers/input/serio/serport.c b/drivers/input/serio/serport.c index 22f73683952b..f6b85222ba3d 100644 --- a/drivers/input/serio/serport.c +++ b/drivers/input/serio/serport.c @@ -27,11 +27,15 @@ MODULE_LICENSE("GPL"); MODULE_ALIAS_LDISC(N_MOUSE); #define SERPORT_BUSY 1 +#define SERPORT_ACTIVE 2 +#define SERPORT_DEAD 3 struct serport { struct tty_struct *tty; wait_queue_head_t wait; struct serio *serio; + struct serio_device_id id; + spinlock_t lock; unsigned long flags; }; @@ -45,11 +49,29 @@ static int serport_serio_write(struct serio *serio, unsigned char data) return -(serport->tty->driver->write(serport->tty, &data, 1) != 1); } +static int serport_serio_open(struct serio *serio) +{ + struct serport *serport = serio->port_data; + unsigned long flags; + + spin_lock_irqsave(&serport->lock, flags); + set_bit(SERPORT_ACTIVE, &serport->flags); + spin_unlock_irqrestore(&serport->lock, flags); + + return 0; +} + + static void serport_serio_close(struct serio *serio) { struct serport *serport = serio->port_data; + unsigned long flags; + + spin_lock_irqsave(&serport->lock, flags); + clear_bit(SERPORT_ACTIVE, &serport->flags); + set_bit(SERPORT_DEAD, &serport->flags); + spin_unlock_irqrestore(&serport->lock, flags); - serport->serio->id.type = 0; wake_up_interruptible(&serport->wait); } @@ -61,36 +83,21 @@ static void serport_serio_close(struct serio *serio) static int serport_ldisc_open(struct tty_struct *tty) { struct serport *serport; - struct serio *serio; - char name[64]; if (!capable(CAP_SYS_ADMIN)) return -EPERM; - serport = kmalloc(sizeof(struct serport), GFP_KERNEL); - serio = kmalloc(sizeof(struct serio), GFP_KERNEL); - if (unlikely(!serport || !serio)) { - kfree(serport); - kfree(serio); + serport = kcalloc(1, sizeof(struct serport), GFP_KERNEL); + if (!serport) return -ENOMEM; - } - memset(serport, 0, sizeof(struct serport)); - serport->serio = serio; - set_bit(TTY_DO_WRITE_WAKEUP, &tty->flags); serport->tty = tty; - tty->disc_data = serport; - - memset(serio, 0, sizeof(struct serio)); - strlcpy(serio->name, "Serial port", sizeof(serio->name)); - snprintf(serio->phys, sizeof(serio->phys), "%s/serio0", tty_name(tty, name)); - serio->id.type = SERIO_RS232; - serio->write = serport_serio_write; - serio->close = serport_serio_close; - serio->port_data = serport; - + spin_lock_init(&serport->lock); init_waitqueue_head(&serport->wait); + tty->disc_data = serport; + set_bit(TTY_DO_WRITE_WAKEUP, &tty->flags); + return 0; } @@ -100,7 +107,8 @@ static int serport_ldisc_open(struct tty_struct *tty) static void serport_ldisc_close(struct tty_struct *tty) { - struct serport *serport = (struct serport*) tty->disc_data; + struct serport *serport = (struct serport *) tty->disc_data; + kfree(serport); } @@ -116,9 +124,19 @@ static void serport_ldisc_close(struct tty_struct *tty) static void serport_ldisc_receive(struct tty_struct *tty, const unsigned char *cp, char *fp, int count) { struct serport *serport = (struct serport*) tty->disc_data; + unsigned long flags; int i; + + spin_lock_irqsave(&serport->lock, flags); + + if (!test_bit(SERPORT_ACTIVE, &serport->flags)) + goto out; + for (i = 0; i < count; i++) serio_interrupt(serport->serio, cp[i], 0, NULL); + +out: + spin_unlock_irqrestore(&serport->lock, flags); } /* @@ -141,16 +159,33 @@ static int serport_ldisc_room(struct tty_struct *tty) static ssize_t serport_ldisc_read(struct tty_struct * tty, struct file * file, unsigned char __user * buf, size_t nr) { struct serport *serport = (struct serport*) tty->disc_data; + struct serio *serio; char name[64]; if (test_and_set_bit(SERPORT_BUSY, &serport->flags)) return -EBUSY; + serport->serio = serio = kcalloc(1, sizeof(struct serio), GFP_KERNEL); + if (!serio) + return -ENOMEM; + + strlcpy(serio->name, "Serial port", sizeof(serio->name)); + snprintf(serio->phys, sizeof(serio->phys), "%s/serio0", tty_name(tty, name)); + serio->id = serport->id; + serio->id.type = SERIO_RS232; + serio->write = serport_serio_write; + serio->open = serport_serio_open; + serio->close = serport_serio_close; + serio->port_data = serport; + serio_register_port(serport->serio); printk(KERN_INFO "serio: Serial port %s\n", tty_name(tty, name)); - wait_event_interruptible(serport->wait, !serport->serio->id.type); - serio_unregister_port(serport->serio); + wait_event_interruptible(serport->wait, test_bit(SERPORT_DEAD, &serport->flags)); + serio_unregister_port(serport->serio); + serport->serio = NULL; + + clear_bit(SERPORT_DEAD, &serport->flags); clear_bit(SERPORT_BUSY, &serport->flags); return 0; @@ -163,16 +198,15 @@ static ssize_t serport_ldisc_read(struct tty_struct * tty, struct file * file, u static int serport_ldisc_ioctl(struct tty_struct * tty, struct file * file, unsigned int cmd, unsigned long arg) { struct serport *serport = (struct serport*) tty->disc_data; - struct serio *serio = serport->serio; unsigned long type; if (cmd == SPIOCSTYPE) { if (get_user(type, (unsigned long __user *) arg)) return -EFAULT; - serio->id.proto = type & 0x000000ff; - serio->id.id = (type & 0x0000ff00) >> 8; - serio->id.extra = (type & 0x00ff0000) >> 16; + serport->id.proto = type & 0x000000ff; + serport->id.id = (type & 0x0000ff00) >> 8; + serport->id.extra = (type & 0x00ff0000) >> 16; return 0; } @@ -182,9 +216,13 @@ static int serport_ldisc_ioctl(struct tty_struct * tty, struct file * file, unsi static void serport_ldisc_write_wakeup(struct tty_struct * tty) { - struct serport *sp = (struct serport *) tty->disc_data; + struct serport *serport = (struct serport *) tty->disc_data; + unsigned long flags; - serio_drv_write_wakeup(sp->serio); + spin_lock_irqsave(&serport->lock, flags); + if (test_bit(SERPORT_ACTIVE, &serport->flags)) + serio_drv_write_wakeup(serport->serio); + spin_unlock_irqrestore(&serport->lock, flags); } /*