Messages in this thread | | | Date | Fri, 19 Mar 2010 11:08:37 +0000 | From | Alan Cox <> | Subject | Re: [PATCH] move tty_kref_put() outside of __cleanup_signal() |
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> This task is new, nobody can see/use it before we drop the locks. NULL or not, > its signal->tty is just uninitialized yet.
Fair enough.
> > > > --- 34-rc1/kernel/exit.c~7_TTY_PUT 2010-03-17 20:05:38.000000000 +0100 > > > +++ 34-rc1/kernel/exit.c 2010-03-18 22:46:41.000000000 +0100 > > > @@ -150,6 +150,7 @@ static void __exit_signal(struct task_st > > > * see account_group_exec_runtime(). > > > */ > > > task_rq_unlock_wait(tsk); > > > + tty_kref_put(sig->tty); > > > > and a sig->tty = NULL assignment to trap races might not go amiss here > > perhaps ? > > Indeed ;) > > The subsequent patches will do this, we need more changes anyway. Currently > this doesn't matter because we are going to kfree() this memory unconditionally. > But when we pin ->signal to task_struct, we should clear ->signal->tty before > we drop ->siglock, then tty_kref_put().
Ok - yes the moment you start refcounting ->signal that changes (or do you expect to free ->tty when you destruct the signals ?)
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