Messages in this thread | | | Subject | Re: [PATCH net-next 2/3] bpf: introduce BPF_MAP_TYPE_STACK_TRACE | From | Alexei Starovoitov <> | Date | Thu, 25 Feb 2016 08:42:40 -0800 |
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On 2/25/16 6:23 AM, Peter Zijlstra wrote: >> + id = hash & (smap->n_buckets - 1); > Its not at all clear where the corresponding rcu_read_lock() is at. > >> >+ bucket = rcu_dereference(smap->buckets[id]);
bpf programs of all types are always executing under rcu_read_lock(). This is fundamental for maps and majority of the helpers that's why there is no WARN_ON(rcu_read_lock_held) in this helper, since we already have it in many other places. The rcu_read_lock() for kprobe type is in trace_call_bpf().
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