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| author |   Richard Watts <rrw@kynesim.co.uk> | 2015-05-19 16:06:53 +0100 |
|---|---|---|
| committer |   Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2015-08-03 15:24:43 -0700 |
| commit | a3a10ce3429e5dee623ad5c8407ea58e204fcb0a (patch) | |
| tree | e1a986e9e5e4c1c313f658eb70e599256c6d20c6 /drivers/tty | |
| parent | Revert "tty: serial: imx.c: Reset UART before activating interrupts" (diff) | |
| download | linux-dev-a3a10ce3429e5dee623ad5c8407ea58e204fcb0a.tar.xz linux-dev-a3a10ce3429e5dee623ad5c8407ea58e204fcb0a.zip | |
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>
Diffstat (limited to 'drivers/tty')
| -rw-r--r-- | drivers/tty/tty_io.c | 24 |
1 files changed, 16 insertions, 8 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); |