Messages in this thread | | | From | Sasha Levin <> | Date | Tue, 28 Feb 2012 16:13:23 +0200 | Subject | Re: lockdep: Warning & NULL ptr deref |
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On Tue, Feb 28, 2012 at 3:29 PM, Peter Zijlstra <peterz@infradead.org> wrote: > On Tue, 2012-02-28 at 10:24 -0500, Sasha Levin wrote: >> >> I'll send some patches to prevent the NULL deref itself which happens >> since a chunk of the code in lockdep.c assumed hlock_class() can't >> return NULL. >> > There's tons of code actually assuming that.. > >> This won't fix the actual problem though, I'm not sure exactly how a >> held lock wouldn't have a class initialized to it. > > static inline struct lock_class *hlock_class(struct held_lock *hlock) > { > if (!hlock->class_idx) { > /* > * Someone passed in garbage, we give up. > */ > DEBUG_LOCKS_WARN_ON(1); > return NULL; > } > return lock_classes + hlock->class_idx - 1; > } > > Typically that translates to severe memory corruption.
Hm... In this case, maybe it's safer to change that warning to BUG()? Running past that point can only case harm... -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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