Messages in this thread | | | Subject | Re: [patch 1/6] mmu_notifier: Core code | From | Peter Zijlstra <> | Date | Wed, 30 Jan 2008 18:10:32 +0100 |
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On Wed, 2008-01-30 at 16:37 +0100, Andrea Arcangeli wrote: > On Tue, Jan 29, 2008 at 06:29:10PM -0800, Christoph Lameter wrote: > > +void mmu_notifier_release(struct mm_struct *mm) > > +{ > > + struct mmu_notifier *mn; > > + struct hlist_node *n, *t; > > + > > + if (unlikely(!hlist_empty(&mm->mmu_notifier.head))) { > > + rcu_read_lock(); > > + hlist_for_each_entry_safe_rcu(mn, n, t, > > + &mm->mmu_notifier.head, hlist) { > > + hlist_del_rcu(&mn->hlist); > > This will race and kernel crash against mmu_notifier_register in > SMP. You should resurrect the per-mmu_notifier_head lock in my last > patch (except it can be converted from a rwlock_t to a regular > spinlock_t) and drop the mmap_sem from > mmu_notifier_register/unregister.
Agreed, sorry for this oversight.
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