diff options
| author | Uwe Kleine-König <Uwe.Kleine-Koenig@digi.com> | 2008-04-11 11:07:39 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2008-04-19 19:10:18 -0700 |
| commit | 610ad5064cb90aec35f5837bbde3d316fe02aca7 (patch) | |
| tree | 7c254ffa06ebd33b5a5b40dc28147eeba615d374 /drivers/uio | |
| parent | b54f2863a26d2b7c002d96abcde149940733c8e6 (diff) | |
| download | lwn-610ad5064cb90aec35f5837bbde3d316fe02aca7.tar.gz lwn-610ad5064cb90aec35f5837bbde3d316fe02aca7.zip | |
UIO: hold a reference to the device's owner while the device is open
Otherwise the device might just disappear while /dev/uioX is being used
which results in an Oops.
Signed-off-by: Uwe Kleine-König <Uwe.Kleine-Koenig@digi.com>
Signed-off-by: Hans J Koch <hjk@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers/uio')
| -rw-r--r-- | drivers/uio/uio.c | 36 |
1 files changed, 21 insertions, 15 deletions
diff --git a/drivers/uio/uio.c b/drivers/uio/uio.c index 11759080ca54..55cc7b80422a 100644 --- a/drivers/uio/uio.c +++ b/drivers/uio/uio.c @@ -301,23 +301,33 @@ static int uio_open(struct inode *inode, struct file *filep) if (!idev) return -ENODEV; + if (!try_module_get(idev->owner)) + return -ENODEV; + listener = kmalloc(sizeof(*listener), GFP_KERNEL); - if (!listener) - return -ENOMEM; + if (!listener) { + ret = -ENOMEM; + goto err_alloc_listener; + } listener->dev = idev; listener->event_count = atomic_read(&idev->event); filep->private_data = listener; if (idev->info->open) { - if (!try_module_get(idev->owner)) - return -ENODEV; ret = idev->info->open(idev->info, inode); - module_put(idev->owner); + if (ret) + goto err_infoopen; } - if (ret) - kfree(listener); + return 0; + +err_infoopen: + + kfree(listener); +err_alloc_listener: + + module_put(idev->owner); return ret; } @@ -336,12 +346,11 @@ static int uio_release(struct inode *inode, struct file *filep) struct uio_listener *listener = filep->private_data; struct uio_device *idev = listener->dev; - if (idev->info->release) { - if (!try_module_get(idev->owner)) - return -ENODEV; + if (idev->info->release) ret = idev->info->release(idev->info, inode); - module_put(idev->owner); - } + + module_put(idev->owner); + if (filep->f_flags & FASYNC) ret = uio_fasync(-1, filep, 0); kfree(listener); @@ -510,10 +519,7 @@ static int uio_mmap(struct file *filep, struct vm_area_struct *vma) return -EINVAL; if (idev->info->mmap) { - if (!try_module_get(idev->owner)) - return -ENODEV; ret = idev->info->mmap(idev->info, vma); - module_put(idev->owner); return ret; } |