Messages in this thread | | | Date | Wed, 10 Nov 2021 12:07:54 +0100 | Subject | Re: [PATCH v3 01/16] perf: Ensure perf_guest_cbs aren't reloaded between !NULL check and deref | From | Paolo Bonzini <> |
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On 11/4/21 15:18, Sean Christopherson wrote: > If I'm interpeting Paolo's suggestion > correctly, he's pointing out that oustanding stores to the function pointers in > @cbs need to complete before assigning a non-NULL pointer to perf_guest_cbs, > otherwise a perf event handler may see a valid pointer with half-baked callbacks. > > I think smp_store_release() with a comment would be appropriate, assuming my > above interpretation is correct. >
Yes, exactly. It should even be rcu_assign_pointer(), matching the synchronize_rcu() in patch 1 (and the change can be done in patch 1, too).
Paolo
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