Module verifier 

BPF verifier log parsing, cycle detection, and output formatting.

Provides:

• VerifierStats / ProgStats / DiffRow — data types
• collect_verifier_output — boot VM, collect stats via host introspection
• format_verifier_output / format_verifier_diff — text formatting
• extract_verifier_log — extract verifier trace from libbpf log blob
• parse_verifier_stats — extract insn/state counts from verifier log
• normalize_verifier_line — strip variable register state annotations
• detect_cycle / collapse_cycles — loop iteration compression
• build_b_map / build_diff_rows — A/B comparison helpers
• SCHED_OUTPUT_START / SCHED_OUTPUT_END — delimiters the guest’s rust_init emits over the bulk port (as MSG_TYPE_SCHED_LOG frames) around the scheduler log region; parse_sched_output extracts the enclosed block

Structs

DiffRow

A single row in the A/B diff output.

ProgStats

Per-program verifier statistics collected from a VM run.

VerifierCellRecord

One cargo ktstr verifier cell’s outcome. The cell process writes it (via write_cell_record) into the directory named by crate::KTSTR_VERIFIER_RESULT_DIR_ENV; after nextest returns the dispatcher reads them back (via read_cell_records) and renders the per-(topology × scheduler) summary table. A cell is one (scheduler, kernel, topology): the verifier sweeps each declared scheduler across topologies, so topology IS a result axis — a scheduler can pass on one topology and fail on another.

VerifierStats

Parsed verifier stats from the kernel log line: processed N insns (limit M) max_states_per_insn X total_states Y peak_states Z mark_read W

VerifierVmResult

Result of collecting verifier output from a VM run.

Enums

AttachOutcome

Whether the scheduler positively confirmed it turned on during a verifier VM run.

Functions

build_b_map

Build the B-side lookup map from collected stats.

build_diff_rows

Build diff rows from A stats and B lookup map.

build_nextest_args

Build the cargo nextest run argument vector for the verifier sweep.

classify_run_outcome

Decide the cargo ktstr verifier run outcome from nextest’s exit success, whether any per-cell records were produced, and the optional --scheduler filter.

collapse_cycles

Collapse repeating cycles in a verifier log.

collect_verifier_output

Boot a VM and collect verifier statistics via host-side memory introspection. Per-program verified_insns comes from bpf_prog_aux->verified_insns read through the guest’s physical memory. On load failure, libbpf prints the verifier log to stderr; the returned scheduler_log field contains the scheduler’s captured output from the VM.

detect_cycle

Detect a single repeating cycle in a slice of lines.

extract_verifier_log

Extract the verifier instruction trace from a scheduler log blob.

format_verifier_diff

Format an A/B diff table comparing two sets of verifier stats.

format_verifier_output

Format verifier results as text: brief lines per program and collapsed logs.

normalize_verifier_line

Normalize a BPF verifier log line by stripping variable register-state annotations so that lines from different loop iterations compare equal.

parse_verifier_stats

Parse verifier stats from the log output.

read_cell_records

Read every *.json cell record under dir (non-recursive). A missing dir or an unparseable record is skipped (best-effort). Returns records in filesystem-iteration order; render_result_table sorts for a deterministic render.

render_instruction_count_tables

Render one verified_insns table per declared scheduler. Within each scheduler’s section: rows = kernel version, columns = BPF program, and each cell is that program’s verified_insns for the (scheduler, kernel) summarized ACROSS the topologies that ran it — a single number when topology-invariant, lo..hi when it varies (- when that program reported no stats on that kernel).

render_result_table

Render the per-cell records into a summary grid: one row per topology preset, one column per scheduler, aggregating across kernels. Each cell is: