Messages in this thread | | | Date | Tue, 23 Feb 2021 12:06:22 +0100 | From | Peter Zijlstra <> | Subject | Re: [PATCH v4 bpf-next 2/6] bpf: prevent deadlock from recursive bpf_task_storage_[get|delete] |
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On Mon, Feb 22, 2021 at 05:20:10PM -0800, Song Liu wrote: > BPF helpers bpf_task_storage_[get|delete] could hold two locks: > bpf_local_storage_map_bucket->lock and bpf_local_storage->lock. Calling > these helpers from fentry/fexit programs on functions in bpf_*_storage.c > may cause deadlock on either locks. > > Prevent such deadlock with a per cpu counter, bpf_task_storage_busy, which > is similar to bpf_prog_active. We need this counter to be global, because
So bpf_prog_active is one of the biggest turds around, and now you're making it worse ?!
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