From c1cbb7029e81894c056680d61c64741bd2ff246f Mon Sep 17 00:00:00 2001 From: Jarod Wilson Date: Mon, 18 Oct 2010 18:39:20 -0300 Subject: [PATCH] [media] lirc_dev: rework storage for cdev data Fixes an oops when an lirc driver that doesn't provide its own fops is unplugged while the lirc cdev is open. Tested with lirc_igorplugusb, with a special thanks to Timo Boettcher for providing the test hardware. Signed-off-by: Jarod Wilson Signed-off-by: Mauro Carvalho Chehab --- drivers/media/IR/lirc_dev.c | 40 +++++++++++++++++++++---------------- 1 file changed, 23 insertions(+), 17 deletions(-) diff --git a/drivers/media/IR/lirc_dev.c b/drivers/media/IR/lirc_dev.c index 8fdb7e11a138..3ef15625fa84 100644 --- a/drivers/media/IR/lirc_dev.c +++ b/drivers/media/IR/lirc_dev.c @@ -58,13 +58,12 @@ struct irctl { struct task_struct *task; long jiffies_to_wait; - - struct cdev cdev; }; static DEFINE_MUTEX(lirc_dev_lock); static struct irctl *irctls[MAX_IRCTL_DEVICES]; +static struct cdev cdevs[MAX_IRCTL_DEVICES]; /* Only used for sysfs but defined to void otherwise */ static struct class *lirc_class; @@ -170,19 +169,20 @@ static int lirc_cdev_add(struct irctl *ir) { int retval; struct lirc_driver *d = &ir->d; + struct cdev *cdev = &cdevs[d->minor]; if (d->fops) { - cdev_init(&ir->cdev, d->fops); - ir->cdev.owner = d->owner; + cdev_init(cdev, d->fops); + cdev->owner = d->owner; } else { - cdev_init(&ir->cdev, &lirc_dev_fops); - ir->cdev.owner = THIS_MODULE; + cdev_init(cdev, &lirc_dev_fops); + cdev->owner = THIS_MODULE; } - kobject_set_name(&ir->cdev.kobj, "lirc%d", d->minor); + kobject_set_name(&cdev->kobj, "lirc%d", d->minor); - retval = cdev_add(&ir->cdev, MKDEV(MAJOR(lirc_base_dev), d->minor), 1); + retval = cdev_add(cdev, MKDEV(MAJOR(lirc_base_dev), d->minor), 1); if (retval) - kobject_put(&ir->cdev.kobj); + kobject_put(&cdev->kobj); return retval; } @@ -363,6 +363,7 @@ EXPORT_SYMBOL(lirc_register_driver); int lirc_unregister_driver(int minor) { struct irctl *ir; + struct cdev *cdev; if (minor < 0 || minor >= MAX_IRCTL_DEVICES) { printk(KERN_ERR "lirc_dev: %s: minor (%d) must be between " @@ -377,6 +378,8 @@ int lirc_unregister_driver(int minor) return -ENOENT; } + cdev = &cdevs[minor]; + mutex_lock(&lirc_dev_lock); if (ir->d.minor != minor) { @@ -400,11 +403,11 @@ int lirc_unregister_driver(int minor) wake_up_interruptible(&ir->buf->wait_poll); mutex_lock(&ir->irctl_lock); ir->d.set_use_dec(ir->d.data); - module_put(ir->cdev.owner); + module_put(cdev->owner); mutex_unlock(&ir->irctl_lock); } else { lirc_irctl_cleanup(ir); - cdev_del(&ir->cdev); + cdev_del(cdev); kfree(ir); irctls[minor] = NULL; } @@ -418,6 +421,7 @@ EXPORT_SYMBOL(lirc_unregister_driver); int lirc_dev_fop_open(struct inode *inode, struct file *file) { struct irctl *ir; + struct cdev *cdev; int retval = 0; if (iminor(inode) >= MAX_IRCTL_DEVICES) { @@ -447,13 +451,14 @@ int lirc_dev_fop_open(struct inode *inode, struct file *file) goto error; } - if (try_module_get(ir->cdev.owner)) { - ++ir->open; + cdev = &cdevs[iminor(inode)]; + if (try_module_get(cdev->owner)) { + ir->open++; retval = ir->d.set_use_inc(ir->d.data); if (retval) { - module_put(ir->cdev.owner); - --ir->open; + module_put(cdev->owner); + ir->open--; } else { lirc_buffer_clear(ir->buf); } @@ -475,6 +480,7 @@ EXPORT_SYMBOL(lirc_dev_fop_open); int lirc_dev_fop_close(struct inode *inode, struct file *file) { struct irctl *ir = irctls[iminor(inode)]; + struct cdev *cdev = &cdevs[iminor(inode)]; if (!ir) { printk(KERN_ERR "%s: called with invalid irctl\n", __func__); @@ -488,10 +494,10 @@ int lirc_dev_fop_close(struct inode *inode, struct file *file) ir->open--; if (ir->attached) { ir->d.set_use_dec(ir->d.data); - module_put(ir->cdev.owner); + module_put(cdev->owner); } else { lirc_irctl_cleanup(ir); - cdev_del(&ir->cdev); + cdev_del(cdev); irctls[ir->d.minor] = NULL; kfree(ir); } -- 2.20.1