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apk-reverse/docs/tool-verification/README.md
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root ab22b225ff Hardware pass: hardware watchpoints, ETE differential tracing, kernel-side event injection
Add the layer under the software tooling, in the repository's shape: what runs
on a host is measured, and every device-bound or kernel-bound piece is a gated,
labelled template.

- scripts/hw_watch.py: arm64 hardware watchpoints/execution breakpoints. WCR/
  BCR encoders with the 8-byte-window and alignment rules (unit-tested to the
  canonical 0x1FFD/0x3F05), a self-contained on-device ptrace helper that
  compiles clean as a static aarch64 ELF (observed: cross gcc 16.2), adb
  orchestration, and hit decoding to module+offset. The stealth ledger is
  stated three times on purpose: the ptrace route leaves TracerPid visible.
- scripts/ete_capture.py: CoreSight ETE capture with the five gates (kernel
  era, coresight sysfs, cs_etm PMU, perf-with-CORESIGHT, permission), the
  perf/OpenCSD build recipe, and the per-thread record wrapper whose
  --control one-instruction run must pass before any real capture.
- scripts/trace_diff.py: differential reduction of two execution traces into
  first-divergence / divergent regions / blocks-unique-to-each-side.
  Producer-agnostic: Stalker BLK logs (raw or run_probe-wrapped) and decoded
  cs_etm address streams alike, host-tested on synthetic flattened-dispatcher
  fixtures.
- scripts/kernel_instrument_scaffold.py: KPM/LKM watchpoint + register-rewrite
  templates plus an honest userspace carrier; every kernel file carries a
  NOT COMPILED AND NOT LOADED banner that verify enforces, and the
  register-rewrite action is fenced as experimental in the template itself.
- references/hardware-watchpoints.md, references/ete-diff-tracing.md,
  references/kernel-event-injection.md: the mechanism, the gates, the traps,
  and the composition recipes (watch the key buffer; diff two runs; flip the
  decision at the trap), with hand-offs instead of duplication.
- Registration: 3 symptom rows (SKILL.md + routing mirror), 3 reference rows,
  4 script rows, coverage/route-inventory/evidence rows, capability-matrix
  entries, known-limitations entry, eval case 4, README trees and coverage
  paragraphs in both languages, and three EXTENSION evidence records stating
  exactly what was measured on this host (encoders, compile, fixtures,
  generate/verify) and what was not (no watchpoint armed, no cs_etm stream,
  nothing kernel-side compiled or loaded anywhere).

Hardware pass 2: SPE/BRBE crash forensics, address symbolization, VM de-virtualization

Calibrated against the two public obfuscator implementations the user supplied
(dpkg123/ollvm-aosp-toolchain: Hikari-family and Pluto-family flattening, the
xvmp IR virtualizer at 63fec41f/9b7cf75e; fetched read-only into
tools/_work/refs, git-ignored). Source facts observed, runtime inferred.

- scripts/trace_addr2sym.py: runtime addresses -> symbol + static offset,
  zero-dependency ELF64 (PT_LOAD vaddr<->file-off conversion, .dynsym/.symtab,
  stripped section+off fallback). Host-verified against a real cross-compiled
  aarch64 .so with readelf as the independent cross-check, plus a hand-built
  minimal ELF covering vaddr!=offset; accepts hw_watch hits, trace mod+off
  keys, or raw address lists. Fixes on the way: --base int coercion, and
  nearest-below symbol semantics for PCs in inter-symbol gaps.
- scripts/vm_handler_slice.py: slice an interpreter trace into handler
  segments (dispatcher detection = histogram top + predecessor diversity; the
  first 4x-margin rule refused the calibrated fixture itself and was replaced),
  signature clustering, open-tail handling, and the guest-opcode trajectory via
  an optional handler->opcode map. Calibrated against xvmp's documented shape:
  vm_exec(code,size,vm_args,num) stubs, boxed arguments observable before
  interpretation, 11 opcodes + 19 arithmetic sub-ops, const-materialization
  dispatch as a distinct segment.
- references/hardware-sampling-and-crash.md: SPE (data flow without a known
  address; PC + data address per sample), BRBE (branch records when a crash
  stack cannot be trusted), the crash loop (tombstone -> branch records ->
  symbolize), and what each adds to the OLLVM/VMP routes. All
  documented-and-gated: no SPE sample or BRBE record was captured here.
- Flattening-recipe corrections from source: Hikari keeps a frame-resident
  switchVar written through an indirect pointer with scramble32-permuted cases;
  Pluto stores switchVar/switchXor rolling-XOR so memory only ever holds noise
  -- hardware-watchpoints.md's state-variable recipe now distinguishes the
  families, and ete-diff-tracing.md carries the family table plus the xvmp
  shape. AntiDebugging injects raw svc inline asm with randomized fields, so
  byte signatures cannot survive it; semantic site-location can.
- Registration: 3 symptom rows (untrustworthy crash stack; runtime addresses
  needing symbols; interpreter loop reading as noise), reference/script rows,
  coverage/evidence/capability-matrix entries, README trees in both languages,
  and EXTENSION-sampling-crash.md recording exactly what was measured (real .so
  symbolization, slicer fixtures, the slicer's self-found dispatcher-rule bug)
  and what was not (no SPE/BRBE capture, no hardened binary ever traced).

Fix all PR #1 review findings by severity; un-entrench the tests that pinned them

Major (device-breaking / wrong results):
- hw_watch: match the arm64 user_hwdebug_state slot ABI (address register
  first, control second -- the swap armed nothing correctly)
- hw_watch: every post-seize error path now clears slots and detaches;
  PTRACE_O_EXITKILL turned an analysis failure into a SIGKILL of the target
- hw_watch: forward genuine target SIGTRAPs (raise/tgkill/int3); only ptrace
  event stops are consumed -- the reference's signal-preservation promise
- hw_watch: run checks push/build/chmod and the helper's exit status; a dead
  capture is RESULT=blocked, never ok-no-hits
- hw_watch: decode offsets from the module base, not each mapping's start
- ete_capture: --control now requires the control record to DECODE
  (perf script event lines), the documented gate, not just a zero exit
- ete_capture: -o before the -- workload separator in --cmd mode; all
  values shell-quoted into su -c; stale remote perf.data removed first;
  perf exit status checked (timeout's 124 is the normal window end)
- kernel scaffold: --set-reg restricted to x0..x30; the rewrite is gated by
  its own breakpoint event so a watchpoint hit cannot run it; LKM pins the
  task (get/put_task_struct) across registration and calls the four-argument
  register_user_hw_breakpoint; --break rows initialize .addr/.len/.bp_type
  (there is no .pc member); --id validated against the module-id grammar
- trace_addr2sym: exact module matching (path or basename, never substring);
  load bias aligned against the PT_LOAD (bias = start - (foff - p_offset)
  - p_vaddr); PCs outside the ELF span are refused instead of landing on the
  last symbol; --json stdout is a pure document (RESULT= in text mode only)
- trace_diff: block keys need 0x or >=8 hex digits (PIDs/counts no longer
  parse); vm_handler_slice: dispatcher needs predecessor diversity, no
  frequency-margin fallback; both JSON outputs pure (check_commands' rule)

Minor/nitpick:
- capability-matrix + evidence-summary: trace reduction status ok->partial
  (no real-target producer ran it; the file's own definition of ok)
- hardware-sampling-and-crash.md and the script examples carry --elf
- kernel-event-injection.md no longer claims the callback's first statement
  is a filter (it prints unfiltered; the filter is a required change)
- Elf64 caches symbol addresses for per-row bisect
- docstring coverage of the touched surface: 16.67% -> 100%

Tests: every json.loads workaround stripping RESULT= is gone; new regression
tests cover the slot ABI, release-on-error, SIGTRAP forwarding, non-first
mapping offsets, -o placement and su -c quoting, the control decode gate,
x31/--id refusals, the guarded rewrite, outside-ELF PCs and bias math,
short-token refusal and the dispatcher margin rule. The minimal-ELF fixture
now packs a full 8-field Elf64_Phdr (its 7-field pack silently shifted
p_memsz onto p_align). 739 passed; flake8/mypy and all five gates clean.

Address the follow-up review on 0bd8dfe (6 findings)

- ete_capture: two-layer quoting for the control-record, decode and cleanup
  commands -- shlex.quote spliced between literal single quotes broke out of
  su -c for any spaced output name; --seconds must be positive (timeout 0
  disables the timer), refused before any adb check
- kernel scaffold: --set-reg now refuses sp/pc as well (the template has no
  rewrite path for them; a generate that silently drops the action is the
  misleading kind of success); both templates arm with a sampling period
  (LKM via hw_breakpoint_init, KPM spells out sample_period=1) -- a zero
  period is a non-sampling event whose callback never fires: armed, silent
- trace_addr2sym: contains_vaddr tests each PT_LOAD's loaded span instead
  of the whole-file extent; a PC in the unmapped gap between segments is
  refused rather than named after the nearest symbol below
- trace_diff: a bare all-digit token is indistinguishable from a date or
  count, so block keys need 0x or a non-decimal hex digit; a date-only log
  stays refused as a capture failure

Tests: two-layer quoting with a spaced control name, --seconds refusal,
sp/pc in the rejection list, sampling-period assertions for both templates,
a two-segment gap fixture, and a date-only parser case. 743 passed; flake8,
mypy and all five gates clean.
2026-10-15 15:33:28 +08:00

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Markdown

# Tool verification record
This directory is the **evidence record for the `apk-reverse` skill measured against real
targets**, kept separate from the skill itself so the Coverage statement in `SKILL.md` can be
checked against the runs behind it, and so a later reader can tell which claims were *observed*,
which were *inferred*, and which are still *unverified*.
It is **not** a set of target-specific notes kept for reuse, and it deliberately carries **no target
identity**. The measurements are about the **tools and the skill**; they stay valid whichever APK
produced them. Where a concrete figure was needed to make a point (a class count, a file size, a
build time) the figure is kept and the target is named generically.
Targets measured: Flutter AOT applications, multi-dex, mid-size native library sets, no packer.
The APKs themselves are **not** in this repository (`.gitignore` excludes `*.apk`, and `tools/`).
**Workbench paths are an operation record, not a pointer.** A record may say a run happened *at*
`tools/_work/...` so the command can be judged; `.gitignore` excludes `tools/`, so that path is not
something a reader can open. Anything a reader is *meant* to follow is named under
`docs/tool-verification/` or inside the skill — that rule is why a reference document never cites a
`tools/` path as its evidence, even when the work happened there.
## Strength labels
Every claim carries one of three labels, used the same way `references/verification.md` uses them:
- **observed** — reproduced here, with the exact command and its output.
- **inferred** — follows from observed facts, but the step itself was not executed.
- **unverified** — assumed or reported by a tool and not independently confirmed.
## Index
| File | Covers |
|---|---|
| `TOOL-VERDICTS.md` | One verdict per tested script and external toolchain, with the independent cross-check behind it |
| `FINDINGS.md` | Findings about the skill itself: defects, contradictions, boundary evidence |
| `REPO-DECISIONS.md` | What changed in the repo as a result, and what deliberately did not |
## Extension-pass record
The extension pass (the six coverage gaps named in the external review: module ecosystem, extraction
shells and VMP, emulation/RPC, native DBI, kernel-level environment, protocol layers) keeps its
evidence here, one file per topic, in the same three labels:
| File | Covers |
|---|---|
| `EXTENSION-device-run.md` | The on-device run against a hardened Flutter sample: the two control runs, the frida refusals, the **twice-corrected** pid-drift attribution, the failed-dump artefacts checked with `dex_dump_validate.py`, and a shared-device hazard measured with Stalker |
| `EXTENSION-unpacking.md` | Extraction-shell diagnosis by trivial-body ratio, `dex_dump_validate.py` against a fixture derived from the sample's own shell dex, and the tool's own defect found during the run |
| `EXTENSION-rootdump.md` | The root-side `/proc/<pid>/maps` + `mem` route that does not use frida: 17 real dex images recovered, the shell skeleton they are not, four device-shell traps, and the negative result on anonymous/ART-heap scanning |
| `EXTENSION-lsposed.md` | Module route: the gradle-free build chain with timings, three build traps, LSPosed config-DB anatomy, the module that could never have worked, and the root-hiding configuration the device actually has |
| `EXTENSION-emulation-rpc.md` | ASC/`ddc` measured on a hardened APK, Frida-RPC exercised end to end on a live device, and the unidbg build repair |
| `EXTENSION-native-dbi.md` | Stalker: the zero-event boundary, the crash from following a hot libc export, and an offline protobuf round-trip that caught a defect in its own decoder |
| `EXTENSION-kernel-ondevice.md` | The MT Manager APK MCP probe, the module-environment facts it could verify, and the kernel routes that this device's 4.14 kernel puts out of reach |
## Benchmark-pass record
The benchmark pass put **public targets** under the documented routes — `tests/benchmark.md` is the
matrix, and these files are the evidence behind its rows. Same three labels. Several of these rows
came back negative, and four of them overturned a conclusion this repository had already recorded;
those are called out in the matrix rather than buried here.
| File | Covers |
|---|---|
| `EXTENSION-benchmark-l1-l3.md` | The first two matrix rows: the L1 equal-length patch -> repack -> re-sign chain with its on-screen behaviour change and its zero-change control, and the L3 time-to-death baseline, the two spawn/patch/detach orderings that cannot work, and the terminate path that patching the obvious death site does not stop |
| `EXTENSION-extraction-shell-bench.md` | `dex_dump_validate.py` against an 11-variant skeleton set: the trivial-body ratio as a bimodal result rather than a threshold, the three script defects the variants exposed, and the ranking that pointed at a modified image until independent review caught it |
| `EXTENSION-stalker-exclude.md` | Stalker exclusion measured across three arms: the no-follow baseline, the follow that kills the process, and the follow with 20 modules excluded that survives but still delivers zero events |
| `EXTENSION-java2c.md` | Java2C against JNI sinking: native-declaration density roughly 2000x apart, why a `Java_*` symbol search fails silently, and the Dex-to-C build chain no toolchain on this host could complete |
| `EXTENSION-vmp-diff.md` | The known-plaintext differential: a 218-of-224-opcode coverage fixture, a closed-loop check that recovered 218/218 mappings with zero fabrications, and the one link that cannot be automated |
| `EXTENSION-kernel-weapons.md` | The generated KernelSU/APatch scaffold and its three kernel-side templates, all shipped unbuilt, plus the structural correction that a userspace module cannot change a syscall return value |
| `EXTENSION-split-apk.md` | Two real split sets through both branches: unified re-signing, the merge that is refused by design, the merge that succeeds, and the signer chain this host actually needs |
| `EXTENSION-reconstruction.md` | The reconstruction pass: the doctor capability closure (a JDK-only PATH used to report "can re-sign", now `BLOCKED` with a next action), the zip rebuild that stops dropping per-entry metadata (`zipalign -c -v 4` fails the old output and passes the new), and `check_commands.py` catching a documented flag that does not exist |
| `EXTENSION-test-harness.md` | The executable half of the evidence: what `tests/` asserts and what it measured, the `dex_patch_bytes` regression reproduced byte-for-byte, the 153 skips and 26 xfails that form the exit-code work order, the device-bound exclusion forced by an incident where the suite drove a real phone, and CI written but never run |
| `EXTENSION-rasc.md` | The Rust ASC measured against the Python one: identical class-definition sets on two archives, the speedup per scenario, the build (no prebuilt artifact exists, and a 32-bit MinGW cannot link it), and **the enum shape whose method bodies it drops with no warning** |
| `EXTENSION-protobuf-raw.md` | A schema-free decoder cross-checked against the official runtime and a real DataStore container, with the packed-boundary and proto3-zero ambiguities reproduced on real bytes |
## Absorption-pass record
A later pass absorbed mechanics from external skill repositories (`reverse-skill`,
`awesome-game-security`, `android-reverse-engineering-claude-skill`, `MobileRE-Skill`), keeping each
project's own discipline: only the phase, the checklist and the command pattern cross over, with the
source URL and the access date recorded, and nothing vendored as a runtime dependency. These files
live here rather than in the skill because two of them corrected a claim the repository had already
written down.
| File | Covers |
|---|---|
| `EXTENSION-desensitization.md` | The leak scanner's rules and exemptions, its four `RESULT=` states and exit codes, the escaping false positives, and **the pass that found its own evidence file leaking 26 strong hits** — the fixture's literal match values, quoted to prove the rules fire |
| `EXTENSION-dart-aot-formats.md` | Two string-table claims tested against a real dual-ABI Flutter app: the arm64 packed scheme confirmed against literal tag bytes, and the assumed armv7 `len*2`/UTF-16 form **refuted** — the 32-bit record is `[header u32][byte-count u32le][UTF-8]`, and the extractor's zero is a format mismatch rather than an empty table |
| `EXTENSION-detection-pipeline.md` | Naming the check that fires: three arms on a public MASTG target (control alive, probe arm dead in ≈300 ms via `strstr("frida")`, with the `TracerPid=0` versus 4-frida-mappings asymmetry), `svc_scan.py`'s two decoders agreeing on an identical 214-site set, the layered Java-to-svc descent, and the ptrace-free dump boundary on targets whose dex is deflated inside the APK |
## Hardware-layer pass record
The hardware pass (hardware watchpoints, ETE differential tracing, kernel-side event injection)
follows the same shape: what runs on a host is measured, and everything that needs a device or a
kernel toolchain is an explicitly-labelled template whose gate says where it closes.
| File | Covers |
|---|---|
| `EXTENSION-hw-watchpoints.md` | The ptrace hardware-watchpoint route: encoders accepted and refused exactly as the alignment rules demand, and the emitted on-device helper **compiled clean as a static aarch64 ELF** — while no watchpoint was armed on any device, and the ledger that says the ptrace route leaves `TracerPid` visible |
| `EXTENSION-ete-diff.md` | The differential half measured on synthetic flattened-dispatcher fixtures (first divergence, unique-per-side sets), the gate/capture plumbing measured to the no-device boundary, and what was deliberately not done: no perf-with-CORESIGHT build, no cs_etm stream, no overhead claim |
| `EXTENSION-kernel-instrument.md` | The kernel-side scaffold's generate/verify round trip, the spec-refusal rules shared with `hw_watch.py`, the capability map whose `no` cells do the gatekeeping, and the three-time-fenced experimental register-rewrite action |
| `EXTENSION-sampling-crash.md` | The second hardware pass: `trace_addr2sym.py` verified against a real cross-compiled `.so` (readelf-cross-checked), the interpreter-trace slicer measured on the calibrated xvmp shape (including the 4x-margin bug it found in itself), and the flattening-recipe corrections read from the two public obfuscator implementations the user supplied |
## Adding a run
Record the tools, versions and exact commands, and label each claim. Keep target-specific facts out:
what belongs here is what a future reader can apply to a *different* APK — a defect, a measured
cost, a method that did or did not work, and the cross-check that settled it.