selftest adjacent tests - #98
Open
r41k0u wants to merge 5 commits into
Open
Conversation
Ports that import from vmlinux need the same treatment as tests/passing_tests/vmlinux/ -- skipped, not failed, when no vmlinux.py has been generated for the running kernel. Without this they fail outright wherever one is absent, CI included. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Ports of programs from tools/testing/selftests/bpf/progs/ in the Linux tree,
each naming its upstream original in a header comment.
tracing/tracepoint_sched_switch.py test_tracepoint.c
tracing/get_cgroup_id.py get_cgroup_id_kern.c
tracing/autoattach.py test_autoattach.c
Deliberately a small spike rather than bulk coverage. The three sample different
global-variable shapes, since substituting for globals is what porting the rest
of the corpus will mostly consist of: none at all (the control case), a scalar
read plus a scalar write, and two flags written from two programs on two
different attach points.
They also widen the range of program types under test.
tracepoint/sched/sched_switch and raw_tp/sys_enter were previously unexercised;
@section writes its string straight into the ELF with no allowlist, so that
pass-through had only ever been tested against a handful of types.
Only the BPF half of each selftest is ported -- upstream pairs every program
with a userspace driver in prog_tests/ that loads and asserts, whereas this
framework compiles and verifies but never runs. tests/README.md now says so
explicitly, along with the WORKAROUND(globals) convention marking each map
substituted for a global.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Ported faithfully from test_perf_skip.c, which reads the sampled instruction pointer out of a perf_event context: ctx.regs.ip. That is two levels of struct field access and PythonBPF supports one, so this lands as a strict expected failure describing the gap. _allocate_for_attribute in allocation_pass.py declines to allocate unless the attribute's base is a plain Name, so the nested form is skipped. One level on the same context works today -- ctx.sample_period compiles and llc's fine. Worth noting for whoever picks this up: the failure surfaces as 'SyntaxError: Undefined variable actual', naming the assignment target rather than the nested access responsible. The allocation pass declines quietly and the expression pass then trips over the missing symbol. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
The four ports were the experiment; this is the result. Covers whether LLM-assisted porting is worth continuing (yes, in feature-sized increments), what a passing port actually proves (a compiler assertion, not a behavioural one), and the four distinct global-variable shapes the spike turned up. Includes the finding that libbpf implements globals as single-element BPF_MAP_TYPE_ARRAY maps, so a one-element ArrayMap -- not a HashMap -- is the structurally faithful stand-in, and that the ELF half of global support already works today via the machinery behind @bpfglobal. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
2 participants
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
Ports some tests from linux kernel's bpf selftests to PythonBPF, based on https://claude.ai/code/artifact/37744cf3-ce6a-42c5-b5bf-88ead0c275d0