diff options
| author | Richard Watts <rrw@kynesim.co.uk> | 2015-05-19 18:06:53 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2015-08-04 01:24:43 +0300 |
| commit | a3a10ce3429e5dee623ad5c8407ea58e204fcb0a (patch) | |
| tree | e1a986e9e5e4c1c313f658eb70e599256c6d20c6 | |
| parent | 458e2c82c5fbfbc431598636c05bdb21feb7056f (diff) | |
| download | linux-a3a10ce3429e5dee623ad5c8407ea58e204fcb0a.tar.xz | |
Avoid usb reset crashes by making tty_io cdevs truly dynamic
Avoid usb reset crashes by making tty_io cdevs truly dynamic
Signed-off-by: Richard Watts <rrw@kynesim.co.uk>
Reported-by: Duncan Mackintosh <DMackintosh@cbnl.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/tty/tty_io.c | 24 | ||||
| -rw-r--r-- | include/linux/tty_driver.h | 2 |
2 files changed, 17 insertions, 9 deletions
diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c index c37a215177c0..02785d844354 100644 --- a/drivers/tty/tty_io.c +++ b/drivers/tty/tty_io.c @@ -3152,9 +3152,12 @@ static int tty_cdev_add(struct tty_driver *driver, dev_t dev, unsigned int index, unsigned int count) { /* init here, since reused cdevs cause crashes */ - cdev_init(&driver->cdevs[index], &tty_fops); - driver->cdevs[index].owner = driver->owner; - return cdev_add(&driver->cdevs[index], dev, count); + driver->cdevs[index] = cdev_alloc(); + if (!driver->cdevs[index]) + return -ENOMEM; + cdev_init(driver->cdevs[index], &tty_fops); + driver->cdevs[index]->owner = driver->owner; + return cdev_add(driver->cdevs[index], dev, count); } /** @@ -3260,8 +3263,10 @@ struct device *tty_register_device_attr(struct tty_driver *driver, error: put_device(dev); - if (cdev) - cdev_del(&driver->cdevs[index]); + if (cdev) { + cdev_del(driver->cdevs[index]); + driver->cdevs[index] = NULL; + } return ERR_PTR(retval); } EXPORT_SYMBOL_GPL(tty_register_device_attr); @@ -3281,8 +3286,10 @@ void tty_unregister_device(struct tty_driver *driver, unsigned index) { device_destroy(tty_class, MKDEV(driver->major, driver->minor_start) + index); - if (!(driver->flags & TTY_DRIVER_DYNAMIC_ALLOC)) - cdev_del(&driver->cdevs[index]); + if (!(driver->flags & TTY_DRIVER_DYNAMIC_ALLOC)) { + cdev_del(driver->cdevs[index]); + driver->cdevs[index] = NULL; + } } EXPORT_SYMBOL(tty_unregister_device); @@ -3347,6 +3354,7 @@ err_free_all: kfree(driver->ports); kfree(driver->ttys); kfree(driver->termios); + kfree(driver->cdevs); kfree(driver); return ERR_PTR(err); } @@ -3375,7 +3383,7 @@ static void destruct_tty_driver(struct kref *kref) } proc_tty_unregister_driver(driver); if (driver->flags & TTY_DRIVER_DYNAMIC_ALLOC) - cdev_del(&driver->cdevs[0]); + cdev_del(driver->cdevs[0]); } kfree(driver->cdevs); kfree(driver->ports); diff --git a/include/linux/tty_driver.h b/include/linux/tty_driver.h index 92e337c18839..161052477f77 100644 --- a/include/linux/tty_driver.h +++ b/include/linux/tty_driver.h @@ -296,7 +296,7 @@ struct tty_operations { struct tty_driver { int magic; /* magic number for this structure */ struct kref kref; /* Reference management */ - struct cdev *cdevs; + struct cdev **cdevs; struct module *owner; const char *driver_name; const char *name; |