Re: [RFC 1/2] kobject_set_name - error handling

Maneesh Soni
2004-05-04T05:35:54Z

On Fri, Apr 30, 2004 at 07:48:13AM -0500, Dmitry Torokhov wrote:
> On Friday 30 April 2004 05:14 am, Maneesh Soni wrote:
>
> > diff -puN drivers/base/bus.c~kobject_set_name-cleanup-01 drivers/base/bus.c
> > --- linux-2.6.6-rc2-mm2/drivers/base/bus.c~kobject_set_name-cleanup-01 2004-04-30 15:14:03.000000000 +0530
> > +++ linux-2.6.6-rc2-mm2-maneesh/drivers/base/bus.c 2004-04-30 15:14:03.000000000 +0530
> > @@ -451,7 +451,9 @@ int bus_add_driver(struct device_driver
> >
> > if (bus) {
> > pr_debug("bus %s: add driver %s\n",bus->name,drv->name);
> > - kobject_set_name(&drv->kobj,drv->name);
> > + error = kobject_set_name(&drv->kobj,drv->name);
> > + if (error)
> > + return error;
>
> Hi, I think you are leaking a reference here, put_bus() is needed.
>
> > drv->kobj.kset = &bus->drivers;
> > if ((error = kobject_register(&drv->kobj))) {
> > put_bus(bus);
>

Thanks for spotting it. Corrected patch is appended.

Greg, Are the patches fit for inclusion? I need to know this as my sysfs backing
store patches are taking back seats because of these changes, particulary the
one in second patch :-(.

Thanks
Maneesh

o The following patch cleans up the kobject_set_name() users. Basically checking
return code from kobject_set_name(). There can be error returns like -ENOMEM
or -EFAULT from kobject_set_name() if the name length exceeds KOBJ_NAME_LEN.

drivers/base/bus.c | 14 +++++++++++---
drivers/base/sys.c | 5 ++++-
2 files changed, 15 insertions(+), 4 deletions(-)

diff -puN drivers/base/sys.c~kobject_set_name-cleanup-01 drivers/base/sys.c
--- linux-2.6.6-rc3-mm1/drivers/base/sys.c~kobject_set_name-cleanup-01 2004-04-30 16:07:32.000000000 +0530
+++ linux-2.6.6-rc3-mm1-maneesh/drivers/base/sys.c 2004-04-30 16:07:32.000000000 +0530
@@ -180,8 +180,11 @@ int sysdev_register(struct sys_device *

/* But make sure we point to the right type for sysfs translation */
sysdev->kobj.ktype = &ktype_sysdev;
- kobject_set_name(&sysdev->kobj,"%s%d",
+ error = kobject_set_name(&sysdev->kobj,"%s%d",
kobject_name(&cls->kset.kobj),sysdev->id);
+ if (error)
+ return error;
+
pr_debug("Registering sys device '%s'\n",kobject_name(&sysdev->kobj));

/* Register the object */
diff -puN drivers/base/bus.c~kobject_set_name-cleanup-01 drivers/base/bus.c
--- linux-2.6.6-rc3-mm1/drivers/base/bus.c~kobject_set_name-cleanup-01 2004-04-30 16:07:32.000000000 +0530
+++ linux-2.6.6-rc3-mm1-maneesh/drivers/base/bus.c 2004-05-04 11:01:52.000000000 +0530
@@ -451,7 +451,11 @@ int bus_add_driver(struct device_driver

if (bus) {
pr_debug("bus %s: add driver %s\n",bus->name,drv->name);
- kobject_set_name(&drv->kobj,drv->name);
+ error = kobject_set_name(&drv->kobj,drv->name);
+ if (error) {
+ put_bus(bus)
+ return error;
+ }
drv->kobj.kset = &bus->drivers;
if ((error = kobject_register(&drv->kobj))) {
put_bus(bus);
@@ -555,7 +559,11 @@ struct bus_type * find_bus(char * name)
*/
int bus_register(struct bus_type * bus)
{
- kobject_set_name(&bus->subsys.kset.kobj,bus->name);
+ int error = 0;
+
+ error = kobject_set_name(&bus->subsys.kset.kobj,bus->name);
+ if (error)
+ return error;
subsys_set_kset(bus,bus_subsys);
subsystem_register(&bus->subsys);

@@ -569,7 +577,7 @@ int bus_register(struct bus_type * bus)
kset_register(&bus->drivers);

pr_debug("bus type '%s' registered\n",bus->name);
- return 0;
+ return error;
}

_

--
Maneesh Soni
Linux Technology Center,
IBM Software Lab, Bangalore, India
email: maneesh@in.ibm.com
Phone: 91-80-25044999 Fax: 91-80-25268553
T/L : 9243696