Messages in this thread | | | Date | Tue, 5 Aug 2008 09:22:09 -0700 | From | Andrew Morton <> | Subject | Re: [PATCH] Make kthread_stop() not oops when passed a bad pointer |
| |
On Tue, 5 Aug 2008 07:55:59 -0600 Matthew Wilcox <matthew@wil.cx> wrote:
> > Due to some botched error handling code in a driver I was writing, I > recently called kthread_stop(NULL). It's terribly exciting to discover > that you've just oopsed while holding a mutex that's required in order > to shut down. Make kthread_stop a little more robust against numbskulls > like me. > > Signed-off-by: Matthew Wilcox <willy@linux.intel.com> > > diff --git a/kernel/kthread.c b/kernel/kthread.c > index 96cff2f..06c3477 100644 > --- a/kernel/kthread.c > +++ b/kernel/kthread.c > @@ -201,6 +201,9 @@ int kthread_stop(struct task_struct *k) > { > int ret; > > + if (!k || IS_ERR(k)) > + return -EINVAL; > + > mutex_lock(&kthread_stop_lock); >
hrm.
a) as this is a programming error, the programmer would like it not to be hidden. A WARN_ON() would address that.
b) there are many instances of
if (p) kthread_stop(p);
which could now be simplified to
kthread_stop(p);
c) a) and b) are incompatible.
| |