Fix BPF load errors with 5.10 #3
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When starting unixdump, BPF verifier complains about invalid read from stack: 177: (85) call bpf_perf_event_output#25 invalid indirect read from stack off -208+35 size 208 This is because struct notify_t object that we allocate on stack might not be initialized. See similar issue description at: iovisor/bcc#2623 (comment) Zero the data allocated on stack that we pass to bpf_perf_event_output(). Observed with: - linux 5.10.14 - bcc 0.18.0
When starting unixdump, BPF verifier complains about unbounded access: 739: (85) call bpf_probe_read#4 … R2 unbounded memory access, use 'var &= const' or 'if (var < const)' Follow the verifier suggestion, and add a redundant check for the upper bound of the offset passed to bpf_probe_read(). Observed with: - linux 5.10.18 - bcc 0.16.17
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I think the memset one is now done through "notify_memset" added in 7ebb858 . |
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Please see the individual commits for the description of errors encountered when trying to use
unixdumpon Linux 5.10.