diff options
| author | Ben Dooks <ben@fluff.org> | 2008-03-04 15:09:06 -0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2008-04-19 19:10:24 -0700 |
| commit | da009f39f85a3ee9deeb10f0f05ddd4efdd67020 (patch) | |
| tree | ba04c23e0d5a831705f0f9bfe1a9be10aff99a78 | |
| parent | 6c847402e1c69c1cfe2bddeadc8391bacbb3d0a5 (diff) | |
sysdev: detect multiple driver registrations
I've just found how easy it is to accidentally register a sysdev_driver for
two different classes. When this happens, bad things happen as the
sysdev_driver structure keeps has the list entry for the driver
registration.
The following patch makes a WARN_ON() if this happens, although I think
BUG_ON or returning -EAGAIN could also be valid responses to this.
Signed-off-by: Ben Dooks <ben@fluff.org>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
| -rw-r--r-- | drivers/base/sys.c | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/drivers/base/sys.c b/drivers/base/sys.c index 8e13fd942163..1a06c2393719 100644 --- a/drivers/base/sys.c +++ b/drivers/base/sys.c @@ -167,6 +167,22 @@ int sysdev_driver_register(struct sysdev_class *cls, struct sysdev_driver *drv) { int err = 0; + if (!cls) { + printk(KERN_WARNING "sysdev: invalid class passed to " + "sysdev_driver_register!\n"); + WARN_ON(1); + return -EINVAL; + } + + /* Check whether this driver has already been added to a class. */ + if ((drv->entry.next != drv->entry.prev) || + (drv->entry.next != NULL)) { + printk(KERN_WARNING "sysdev: class %s: driver (%p) has already" + " been registered to a class, something is wrong, but " + "will forge on!\n", cls->name, drv); + WARN_ON(1); + } + mutex_lock(&sysdev_drivers_lock); if (cls && kset_get(&cls->kset)) { list_add_tail(&drv->entry, &cls->drivers); |