Re: [PATCH RFC bpf-next 3/6] selftests/bpf: test cases for loop hierarchy computation

[Eduard Zingerman <eddyz87@gmail.com>]

On Tue, 2026-05-26 at 10:25 +0000, sashiko-bot@kernel.org wrote:
> Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
> - [Medium] The expected verifier log output in `fwd_edges_no_loop` incorrectly expects an unconditional jump `(05)` for a conditional jump instruction, which will cause the selftest to fail.
> --
> 
> commit f35c2f4d237eac02dd241fbf85f69d40722f62de
> Author: Eduard Zingerman <eddyz87@gmail.com>
> 
> selftests/bpf: test cases for loop hierarchy computation
> 
> This commit adds test cases covering various branches in bpf_compute_loops
> for loop hierarchy computation. It includes tests for single bounded loops,
> independent loops, nested loops, diamond control flow graphs, and irreducible
> loops.
> 
> > diff --git a/tools/testing/selftests/bpf/progs/verifier_loop_hierarchy.c b/tools/testing/selftests/bpf/progs/verifier_loop_hierarchy.c
> > new file mode 100644
> > index 0000000000000..db26157e3e14a
> > --- /dev/null
> > +++ b/tools/testing/selftests/bpf/progs/verifier_loop_hierarchy.c
> 
> [ ... ]
> 
> > +/* Case C: forward edges, no loops. */
> > +SEC("socket")
> > +__success
> > +__log_level(2)
> > +__msg("          0: {{.*}} (b7) r0 = 1")
> > +__msg("          1: {{.*}} (05) goto pc+2")
> 
> [Severity: Medium]
> Will this test case fail because of a mismatch in the expected verifier log?
> 
> The inline assembly below uses "if r0 > 0 goto 1f;", which is a conditional
> jump. This translates to opcode 0x25 (if r0 > 0x0 goto pc+2), but the __msg
> assertion explicitly expects opcode 0x05 (goto pc+2), which is an
> unconditional jump.

The code is adjusted by constant prop phase.
I'll just the test case to call urandom() and keep conditionals.

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