Messages in this thread | | | Subject | Re: [PATCH -mm -next] ipc,sem: fix lockdep false positive | From | Peter Zijlstra <> | Date | Tue, 26 Mar 2013 14:19:25 +0100 |
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On Mon, 2013-03-25 at 14:42 -0700, Michel Lespinasse wrote: > depth nesting here... > Adding Peter & Ingo for advice about how to proceed
> > +++ b/ipc/sem.c > > @@ -357,7 +357,7 @@ static inline int sem_lock(struct sem_array > *sma, struct sembuf *sops, > > spin_lock(&sma->sem_perm.lock); > > for (i = 0; i < sma->sem_nsems; i++) { > > struct sem *sem = sma->sem_base + i; > > - spin_lock(&sem->lock); > > + spin_lock_nested(&sem->lock, > SINGLE_DEPTH_NESTING); > > } > > locknum = -1; > > }
Right, so as walken said, this isn't going to work right.
I need a little more information as I've not really paid much attention to this stuff. Firstly, is there a limit to sem_nsems or is this a random user specified number? Secondly do we care about lock order at all, or is array order the only order that counts?
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