Fix broken --filter-trace-tc and --filter-trace-xdp #424
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--track-bpf-helpers prefers the raw ksym such as bpf_prog_71868b7d3ecebc37_tail_ipv6_ct_ingress[bpf] that clearly tells it's a bpf prog. The tag shows which exact bpf prog is triggered, considered useful during cilium upgrade when there are multiple bpf prog with a same name but different tags.
That's why ParseKallsyms was changed to use full ksym without stripping any parts.
Do you think we can make --trace-tc and --trace-xdp also use the raw ksym? For me it's also valuable to show tag in case there are xdp/tc bpf with duplicate names.
Also asking @brb 's opinion.
Aha, previously, However, it's acceptable to show the raw ksym including tag for I'll update the commit later. |
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It fails to run with --filter-trace-tc: ```bash 2024/09/24 12:59:02 Attaching tc-bpf progs... 2024/09/24 12:59:02 failed to trace TC progs: failed to trace bpf progs: failed to find address for function entry2 of bpf prog SchedCLS(entry2)cilium#28 ``` Then, I fix it by matching prog ksym with prog tag. And avoid `addr - 1` for `--filter-trace-{tc,xdp}`. ```bash 2024/09/25 13:57:00 Attaching tc-bpf progs... 2024/09/25 13:57:00 Attaching kprobes (via kprobe-multi)... 49 / 49 [--------------------------------------------------------------------------------------------------------------------------------------] 100.00% ? p/s 2024/09/25 13:57:00 Attached (ignored 0) 2024/09/25 13:57:00 Listening for events.. SKB CPU PROCESS NETNS MARK/x IFACE PROTO MTU LEN TUPLE FUNC 0xffff8e151d39be00 6 <empty>:0 4026531840 0 ens33:2 0x0800 1500 98 192.168.241.1:0->192.168.241.133:0(icmp) bpf_prog_e20a685998fd41c8_entry1[bpf](tc) 0xffff8e151d39a500 6 <empty>:0 4026531840 0 ens33:2 0x0800 1500 98 192.168.241.1:0->192.168.241.133:0(icmp) bpf_prog_e20a685998fd41c8_entry1[bpf](tc) 0xffff8e151d39bd00 6 <empty>:0 4026531840 0 ens33:2 0x0800 1500 98 192.168.241.1:0->192.168.241.133:0(icmp) bpf_prog_e20a685998fd41c8_entry1[bpf](tc) 0xffff8e151d39a200 6 <empty>:0 4026531840 0 ens33:2 0x0800 1500 98 192.168.241.1:0->192.168.241.133:0(icmp) bpf_prog_e20a685998fd41c8_entry1[bpf](tc) 0xffff8e151d39a800 6 <empty>:0 4026531840 0 ens33:2 0x0800 1500 98 192.168.241.1:0->192.168.241.133:0(icmp) bpf_prog_e20a685998fd41c8_entry1[bpf](tc) ^C2024/09/25 14:02:16 Received signal, exiting program.. 2024/09/25 14:02:16 Detaching kprobes... 3 / 3 [---------------------------------------------------------------------------------------------------------------------------------------] 100.00% 50 p/s ``` Signed-off-by: Leon Hwang <hffilwlqm@gmail.com>
It fails to run with --filter-trace-xdp: ```bash 2024/09/24 15:38:48 Attaching xdp progs... 2024/09/24 15:38:48 failed to trace XDP progs: failed to trace bpf progs: failed to load objects: program fexit_xdp: attach Tracing/TraceFExit: fexit xdp not supported ``` Signed-off-by: Leon Hwang <hffilwlqm@gmail.com>
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When I want to troubleshoot a network issue with
--filter-trace-tc, it cannot to get the address of bpf prog.After fixing
--filter-trace-tcissue, I find it fails to run with--filter-trace-xdptoo. So, I fix the broken--filter-trace-xdpBTW.Signed-off-by: Leon Hwang hffilwlqm@gmail.com