selftests/bpf: Add tests for kprobe attachment with duplicate symbols

Browse source

bpf_fentry_shadow_test exists in both vmlinux (net/bpf/test_run.c) and
bpf_testmod (bpf_testmod.c), creating a duplicate symbol condition when
bpf_testmod is loaded. Add subtests that verify kprobe behavior with
this duplicate symbol:

In attach_probe:
- dup-sym-{default,legacy,perf,link}: unqualified attach succeeds
  across all four modes, preferring vmlinux over module shadow.
- MOD:SYM qualification attaches to the module version.

In kprobe_multi_test:
- dup_sym: kprobe_multi attach with kprobe and kretprobe succeeds.

bpf_fentry_shadow_test is not invoked via test_run, so tests verify
attach and detach succeed without triggering the probe.

Signed-off-by: Andrey Grodzovsky <andrey.grodzovsky@crowdstrike.com>
Link: https://lore.kernel.org/r/20260407203912.1787502-3-andrey.grodzovsky@crowdstrike.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

...

This commit is contained in:

Andrey Grodzovsky 2026-04-07 16:39:12 -04:00 • committed by Alexei Starovoitov

parent 1870ddcd94

commit cea4323f1c

2 changed files with 109 additions and 0 deletions

Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL

Download patch file Download diff file Expand all files Collapse all files

69

tools/testing/selftests/bpf/prog_tests/attach_probe.c

View file

40

tools/testing/selftests/bpf/prog_tests/kprobe_multi_test.c

View file