Fix ring-buffer map consumer pointer on multiple subscribe/unsubscribe. #3002
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Can you write a bit more in the PR description about the ring buffer map, where we use it in eBPF, why it was broken and how it's fixed now? |
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Fixes #3001
Description
This PR fixes an initialization issue of the consumer pointer of the ring-buffer map, in multiple subscribe/unsubscribe scenarios.
When subscribing for the first time, the
consumer_offsetpointer index starts at 0, then by design it only increments. The issue is when a client quits and subscribes again, ebpfcore will subtract its current consumer offset index from a smaller offset from the client's request, therefore causing an arithmetic exception inebpf_ring_buffer_map_return_bufferwhen attempting to return data from the buffer.The fix now returns the actual consumer offset within the reply to each client subscription, so that the queries are in sync with the current ring-buffer's pointer.
Testing
Local, CI/CD
Documentation
n.a.