tools/killsnoop: migrate to tracepoints - #5546
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Fixes iovisor#3592 This commit updates the python killsnoop tool to use tracepoints for the kill, tkill, and tgkill syscalls. Previously, it used kprobes on sys_kill, which broke on Linux 5.11 due to kernel changes. This brings the python tool in parity with the libbpf-tools C version (sigsnoop), providing a more robust and stable tracing mechanism.
codebyangelo
requested review from
brendangregg,
chenhengqi,
ekyooo and
yonghong-song
as code owners
August 21, 2026 09:22
ekyooo
reviewed
Aug 27, 2026
| }; | ||
| } | ||
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| TRACEPOINT_PROBE(syscalls, sys_enter_kill) |
Collaborator
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TRACEPOINT_PROBE-based BPF programs require Linux 4.7 or later. Please update the test_killsnoop() kernel gate from 4.4 to 4.7, consistent with the existing tracepoint tests.
for example,
--- a/tests/python/test_tools_smoke.py
+++ b/tests/python/test_tools_smoke.py
@@
- @skipUnless(kernel_version_ge(4,4), "requires kernel >= 4.4")
+ @skipUnless(kernel_version_ge(4,7), "requires kernel >= 4.7")
| { | ||
| return probe_exit(args, args->ret); | ||
| } | ||
| ; |
Collaborator
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Please remove the extra blank lines and semicolon.
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Author
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Thank you for the guidance. Done.
Removed unnecessary semicolon and whitespace in killsnoop.py.
ekyooo
approved these changes
Aug 27, 2026
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Fixes #3592
This commit updates the python killsnoop tool to use tracepoints for the kill, tkill, and tgkill syscalls. Previously, it used kprobes on sys_kill, which broke on Linux 5.11 due to kernel changes. This brings the python tool in parity with the libbpf-tools C version (sigsnoop), providing a more robust and stable tracing mechanism.
Description
tracepoints.architectural changes to syscall wrappers caused this kprobe approach to fail. This PR
removes the fragile kprobe logic and replaces it with robust
TRACEPOINT_PROBEmacros forsyscalls:sys_enter_kill,tkill, andtgkill(and their respectivesys_exitcounterparts).
Why this approach
to the underlying function renaming and
pt_regsmapping changes that break kprobes.migrated to this exact tracepoint approach, but the original Python tool was left behind.
This PR brings the Python implementation back into parity and restores its functionality on
all modern kernels.
Checklist
tools/toolname:,libbpf-tools/toolname:,src/cc:,docs:,build:,tests/python:)For new tools only
man/man8/) with an OVERHEAD section*_example.txt)tests/python/test_tools_smoke.py