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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.
76 lines
4.3 KiB
Markdown
76 lines
4.3 KiB
Markdown
# Extension verification — ETE differential tracing (gates, reducer, differ)
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Covers the hardware-layer pass that added `scripts/ete_capture.py`, `scripts/trace_diff.py` and
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`references/ete-diff-tracing.md`. Strength labels as this directory's README defines them.
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Reference environment: Linux container host, Python 3.13, adb present with no device. No
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coresight-capable hardware exists in this environment at all; the reference device of the
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earlier passes (kernel 4.14.186) has the ETE gate closed permanently (`observed` there).
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**Headline: the gate table, the recipe and the capture wrapper are host-measured; the
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differential reducer is host-measured on synthetic flattened-dispatcher fixtures. No ETE trace
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was captured or decoded anywhere in this pass — the producer side is `unverified` and the
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`--control` run exists precisely so the next device says so in one command.**
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---
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## 1. The differ, measured on a synthetic OLLVM shape — observed
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Two fixture logs built to the flattened-dispatcher rhythm `D R1 D R2 …` — run A taking
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`R5/R7` (wrong password), run B taking `R3/R4` (right password), one log in raw
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`stalker_trace.js` grammar, one wrapped by `run_probe.py` (`[ts] [ts] TRACE BLK …`) to prove
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the parser survives both:
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```
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$ python skills/apk-reverse/scripts/trace_diff.py diff --a a.log --b b.log
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run A: 8 events, 5 distinct blocks
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run B: 8 events, 5 distinct blocks
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shared block executions: 6 divergent regions: 2
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first divergence: after run #5 (A) / #5 (B), 5/5 events in, last common block liba.so+0x1000
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region 1 (replace)
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A: liba.so+0x6000 B: liba.so+0x4000
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blocks unique to A ...: 0x6000, 0x8000 blocks unique to B ...: 0x4000, 0x5000
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```
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What the output pins, and why each number is the one the method needs:
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- **the identical prefix** (`D R1 D R2`, 5 events) is the shared machinery — exactly where
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parsing ends and the input-dependent path begins;
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- **first divergence** names the dispatcher entry whose state constant differed;
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- **unique-to-each-side** lists are the input-dependent block set, which is the deliverable
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the reference file's §4 interprets per obfuscation.
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`reduce` on one side prints the histogram with the dispatcher as the wide-margin top
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(4 hits vs 1 for every real block) — the same shape `stalker_report.py` documents for Stalker
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logs, reached from a different producer.
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## 2. Gate and capture plumbing — observed (to the no-device boundary)
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`gates` prints the five-gate table; `gates --device` with adb present but no device degrades
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to five `OPEN` rows and `RESULT=partial` rather than a traceback — measured. `capture --pid 1`
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without a device exits through the pull failure with `RESULT=blocked` and exit code 3
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(no-device capability refusal, per the CLI contract) — measured. `recipe` prints the
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Termux and cross build paths for perf-with-CORESIGHT — `inferred` from the kernel's
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tools/perf CoreSight documentation and the OpenCSD project, not from a build performed here.
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## 3. What this pass deliberately did not do
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- No perf-with-CORESIGHT was built (host or device): the recipe is a documented path, and a
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reader who builds it owes the control record (`capture --control`) before any real capture.
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- No decoded cs_etm stream was fed to `trace_diff.py`; the `plain` parser accepts the
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address-bearing lines `perf script` emits, but that exact pairing is `unverified`.
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- No claim about ETE's runtime overhead or its visibility to targets was measured. The
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reference states the mechanism (no code modification, no ptrace) and refuses to go further.
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## 4. Facts this pass pinned for the next one
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- The differ is **producer-agnostic by design**: the same command answers Stalker logs today
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and cs_etm decode output tomorrow. That is why the diff subcommand ships now, not after the
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first ETE capture — it is useful the day a Stalker pair exists.
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- The five gates each fail **silently** downstream; the reference's table says which silence
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each gate produces. The one-instruction control record is the only gate that exercises the
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whole pipe, which is why `capture` refuses to continue when it fails.
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- Run design is part of the tool contract, not user care: `trace_diff.py` refuses empty logs
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with a message that points at the zero-event diagnostics, because an empty trace is a
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capture failure wearing an analysis result's clothes.
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