From: Alexei Starovoitov <a...@plumgrid.com> Date: Tue, 25 Aug 2015 20:06:30 -0700
> v1 version had a race condition in cleanup path of bpf_prog. > I tried to fix it by adding new callback 'cleanup_rcu' to 'struct tcf_common' > and call it out of act_api cleanup path, but Daniel noticed > (thanks for the idea!) that most of the classifiers already do action cleanup > out of rcu callback. > So instead this set of patches converts tcindex and rsvp classifiers to call > tcf_exts_destroy() after rcu grace period and since action cleanup logic > in __tcf_hash_release() is only called when bind and refcnt goes to zero, > it's guaranteed that cleanup() callback is called from rcu callback. > More specifically: > patches 1 and 2 - simple fixes > patches 2 and 3 - convert tcf_exts_destroy in tcindex and rsvp to call_rcu > patch 5 - removes spin_lock from act_bpf > > The cleanup of actions is now universally done after rcu grace period > and in the future we can drop (now unnecessary) call_rcu from > tcf_hash_destroy() > patch 5 is using synchronize_rcu() in act_bpf replacement path, since it's > very rare and alternative of dynamically allocating 'struct tcf_bpf_cfg' just > to pass it to call_rcu looks even less appealing. Series applied, thanks Alexei. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
