Adds an opt-in diagnostic that emits one tracing line per guest store
overlapping any armed byte address, naming the writer (tid, pc, lr)
plus old/new u32 lanes. Mirrors the --pc-probe / --branch-probe shape;
pc/lr are stamped from worker_prologue via a thread-local Cell, so
default runs (empty watch set) take a single is_empty() check on each
write. Lockstep digest preserved (instructions=100000003 across reruns,
sylpheed_n50m.json golden byte-identical).
Diagnostic infra only; no functional change. Used to identify producers
of dispatch-state writes for the audit-017 / audit-019 hunt.
Sister to --pc-probe / --ctor-probe but emits a single compact one-line
BRANCH-PROBE record per fire (pc, tid, hw, cycle, r3, lr, cr0/cr6 flags)
with no back-chain. Designed for tracing every conditional-branch fire
inside a candidate-gate function so the last PC reached before the
function epilogue identifies the exit branch.
Runtime trace at audit-runs/audit-007/sub_824A9710-trace.log decisively
identifies the priv-11 gate:
- Exit branch: 0x824a9944 (post bl sub_824ABD88 first call)
- Responsible kernel call: NtDeviceIoControlFile, FsCtlCode=0x74004
(registered as stub_success at exports.rs:90)
- Mechanical chain: stub returns 0/SUCCESS without writing OUT, game
reads [out_buf+8], finds zero, assigns hardcoded 0xC0000034
(STATUS_OBJECT_NAME_NOT_FOUND) at sub_824ABD88:0x824abea8-ac, exits
via 0x824a9944's lt branch before priv-11 site at 0x824a99a0.
592→592 tests; lockstep instructions=100000010, swaps=2, draws=0
deterministic across reruns. Read-only diagnostic — no fix this session.
Next session: KRNBUG-IO-003 (real NtDeviceIoControlFile per canary
NullDevice::IoControl for FsCtlCodes 0x70000 + 0x74004).
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Extends `--ctor-probe` machinery into `--pc-probe` (clap alias) with
the optional `PC@DISPATCHER:OFFSET` token form: on a hit, the helper
additionally logs `[disp+off]` — what the producer's
`lwz r3, OFFSET(r3)` is about to read. Reuses `parse_hex_u32`; both
flags share parser + storage.
Read-only diagnostic. Lockstep digest preserved (`run digest matches
golden` at -n 50M `--stable-digest`). 588 tests green.
Decisive findings (full deliverable in `audit-findings.md` /
`audit-runs/audit-005/`):
- Failure mode α confirmed for KRNBUG-AUDIT-004: all 9 producer call
sites for handles 0x100c (5 sites) and 0x15e0 (4 sites) fire 0x at
-n 500M. The producer code path is not reached.
- Set-diff of kernel-call sequences (canary.log oracle vs ours.log
at -n 500M) identifies 11 exports canary calls and we don't:
XGetAVPack, XeCryptSha, XeKeysConsolePrivateKeySign,
ObCreateSymbolicLink, NtDeviceIoControlFile (×2),
XamUserReadProfileSettings (×2), XamTaskSchedule, XamTaskCloseHandle,
KeReleaseSemaphore (×268), KeResetEvent, ExTerminateThread (×2).
- XGetAVPack has exactly one caller (sub_824AB578 at 0x824AB5A0).
The 4 instructions immediately preceding it are:
addi r3, r0, 10 ; privilege bit 10
bl XexCheckExecutablePrivilege
cmpli 0, r3, 0
bc 12, eq, 0x824AB724 ; if r3==0, skip whole block
- exports.rs:193 registers XexCheckExecutablePrivilege as
stub_return_zero. Always returning 0 -> guest takes the branch
and skips the entire AV/crypto/save-data init block.
- The other call site (sub_824A9710 at 0x824A99A0) queries privilege
11 with opposite polarity (bne) -> gates XamTaskSchedule on the
privilege-NOT-set arm. With both stubs returning 0, the guest
walks the wrong arm of every privilege-gated branch.
- This explains why the dispatcher fields read zero
([0x828F3D08+0x50]=0, [0x828F4070+0x24]=0 from AUDIT-004 dumps):
the ctors run, but the producers that would populate those fields
with a non-zero handle never execute.
Next session: replace XexCheckExecutablePrivilege stub with real
priv-bit lookup from XEX header. See audit-findings.md
KRNBUG-AUDIT-005 for the validation matrix.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Diagnostic-only, read-only. Lockstep `instructions=100000002`
preserved bit-exact at -n 100M --stable-digest. 586 → 588 tests.
Adds two read-only diagnostics for the parked-waiter producer hunt:
* `--ctor-probe=0x8217C850,0x...` — at every interpreter step,
if `ctx.pc` is in the configured set, print one `CTOR-PROBE`
line capturing live r3 (= `this` in MSVC PPC ctors), lr
(= return site), sp, plus an 8-frame back-chain with
saved-r31/r30 per frame. Fires once per hit, exactly what the
8-instance-pool probe needed.
* `--dump-addr=0x828F3D08,0x828F4070,0x828F3EC0,...` — at end of
run (after the FOCUS report in `dump_thread_diagnostic`), each
address gets a 128-byte hex + be32 + ASCII dump. Used to
inspect the static dispatcher / job-queue struct layouts
AUDIT-003 identified.
Both gated default-off; empty set is a single `is_empty()` test on
the hot path. No guest state is mutated, so the
`sylpheed_n*m.json` lockstep digest is preserved.
KRNBUG-AUDIT-004 findings (corrects KRNBUG-AUDIT-002/003):
1. **The "8-instance pool" hypothesis for handle 0x1004 is FALSE.**
Probing the inner per-instance ctors `[0x821783D8, 0x82181750,
0x821701C8]` at -n 50M shows each fires EXACTLY ONCE with
r3 = `[0x828F3EC0, 0x828F3D08, 0x828F4070]` respectively. All
three handles are Meyers-style singletons with one dispatcher
each. The "called 8 times" claim came from miscounting raw
entries to the OUTER getter sub_8217C850 — but that getter is
itself a Meyers-singleton-getter; only the FIRST entry cascades
through to bl 0x821783D8 (gated on `[0x828F48D8] bit 0`).
2. **The producer indirection layer is the singleton-getter
itself.** Static byte-scan of .rdata / .data shows 0 hits for
the dispatcher addresses — no static registry table holds them.
But the xrefs table for the OUTER getters reveals 5–6 callers
each, MOSTLY non-create-chain, sharing the canonical producer
pattern: `bl outer_singleton_getter; lwz r3, OFFSET(r3); bl
0x824AA1D8` (with OFFSET=80 for 0x100c, =36 for 0x15e0). So the
AUDIT-003 xref audit was necessary but not sufficient — it
correctly saw "no direct producer references" but missed the
singleton-getter indirection layer.
3. **Dispatcher struct layouts** (128-byte dumps captured at -n
50M --halt-on-deadlock):
- 0x828F3D08 (handle 0x100c): event_handle at +0x4C (0x100c),
thread_handle at +0x48 (0x1010), self-pointer at +0x74,
capacity 7 at +0x28, queue empty (+0/+3C = -1).
- 0x828F4070 (handle 0x15e0): event_handle at +0x20 (0x15e0),
sibling-handle 0x15E4 at +0x1C, queue empty (+0x10 = -1).
- 0x828F3EC0 (handle 0x1004): event_handle at +0x78 (0x1004),
4 guest-heap sub-buffers at +0x20/+0x3C/+0x44/+0x50 in
0x4xxxxxxx range — noticeably different layout from the
other two pure POD job queues.
Files:
crates/xenia-kernel/src/state.rs ctor_probe_pcs / dump_addrs +
fire_ctor_probe_if_match + 2 tests
crates/xenia-app/src/main.rs Exec --ctor-probe / --dump-addr
CLI parsing, prologue hook,
end-of-run struct dumper
audit-findings.md KRNBUG-AUDIT-004 entry
audit-runs/audit-004/ 50M probe runs (v1 outer-getter
hits, v2 inner-ctor hits proving
the singleton hypothesis)
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Adds a read-only MSVC RTTI traversal helper (`read_class_at_this`)
and a `probe_create_stack_classes` integration that walks each
captured back-chain frame for handle creates in `--trace-handles-focus`
and probes each frame's most-likely `this` candidate (live r31/r30/r3
for frame 0; saved-r31/r30 from the prologue spill area at [fp-12]/
[fp-16] for deeper frames). False-positive guard rejects the CRT
static-init iterator pattern (vtable's first two slots must be image-
range function pointers — PPC instruction words like `mflr r12` are
not in 0x82xxxxxx).
`dump_thread_diagnostic` now takes `&GuestMemory` so the FOCUS report
prints, for each parked waiter, a WAIT-THREAD block with full back-
chain frames and per-slot saved-register dump for offline lookup.
End-to-end finding (-n 500M producer-trace):
* Handle 0x100c dispatcher = 0x828F3D08 (image rdata; verified by
sub_82181750 disasm + xref table). [this+0] = -1 sentinel — POD
job queue, NOT a C++ polymorphic class.
* Handle 0x15e0 dispatcher = 0x828F4070 (same shape).
* Handle 0x1004's 8-instance pool members still TBD (MSVC ctors
didn't preserve `this` in r31).
* 0x42450b5c is a separate audit class (heap-allocated, parks via
non-`do_wait_single` path).
Decisive xref audit: every reference to 0x828F3D08 / 0x828F4070 in
the static analysis is in a ctor or the CRT init driver. NO producer
code references either dispatcher base. Confirms `signal_attempts=0`
is unreachable-producer, not broken-producer.
Tests: 581 → 586 green (+5: RTTI-intact / RTTI-stripped / non-object
/ cstring / probe_create_stack integration). `--stable-digest -n
100M` instructions=100000002 unchanged. Master HEAD prior: 6440261.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Adds `walk_guest_back_chain` (PPC EABI back-chain walker) and a
`record_create_with_stack` audit hook gated on `--trace-handles-focus`.
NtCreateEvent / NtCreateSemaphore / NtCreateTimer / XamTaskSchedule now
route through the new helper so focused handles capture up to 6 stack
frames at allocation time. Diagnostic-only, read-only memory access:
unfocused handles pay one HashSet lookup, focused ones pay six
back-chain dereferences. Lockstep determinism preserved.
End-to-end finding: handles 0x1004 (8-instance pool via static ctor at
0x8280F810), 0x100c (singleton built inside main()), 0x15e0 (singleton
in distinct cluster) are silph-framework dispatcher objects whose
producer code is unreached at -n 500M. The producer hunt now has class
ownership; vtable/RTTI readout is the next step.
Tests: 576 → 581 green. `--stable-digest -n 100M` instructions=100000002
unchanged. Master HEAD prior: 9d45efe.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Replace the three XAudio kernel-export stubs (Register/Unregister/SubmitFrame)
with canary-faithful implementations and add a periodic buffer-complete
callback ticker reusing the existing SavedCallbackCtx injection machinery.
Canary parity:
- xboxkrnl_audio.cc:56-93 — read callback_ptr[0..1], wrap callback_arg in a
4-byte big-endian guest heap buffer (`wrapped_callback_arg`), write
`0x4155_xxxx` to *driver_ptr.
- audio_system.cc:139-141 — guest callback receives r3 = wrapped pointer,
not raw callback_arg.
- audio_driver.h:21-24 — frame rate 256 samples / 48 kHz ≈ 5.33 ms.
Implementation:
- New `crates/xenia-kernel/src/xaudio.rs` — `XAudioClient`, `XAudioState`
(8-slot table, pending FIFO, dual-mode ticker), `XAUDIO_INSTR_PERIOD =
48_000` (lockstep) and `XAUDIO_PERIOD = 5.333 ms` (--parallel), same
pattern as KRNBUG-D08 v-sync.
- `try_inject_audio_callback` in xenia-app mirrors `try_inject_graphics_interrupt`,
shares `interrupts.saved` slot for mutex with graphics callbacks.
Gating: ticker + injector run only when `--xaudio-tick` /
`XENIA_XAUDIO_TICK=1`. Default off because Sylpheed's audio callback
enters an infinite `KeWaitForSingleObject` loop on first invocation
(canary's host worker thread provides the buffer-completion fence we
don't model), which hijacks a guest HW thread and regresses
`swaps=2 → 1`. Default-off preserves the lockstep `sylpheed_n*m.json`
goldens exactly.
Producer hunt outcome (FALSIFIED for parked handles 0x1004/0x100c/0x15e4):
at `-n 500M --xaudio-tick` all 3 handles still show
`signal_attempts=0 (primary=0, ghost=0)`. Audio callback is not the
missing producer. Next candidate per audit-findings.md is Timer DPC
delivery (KeSetTimer / KeInsertQueueDpc).
Tests: 562 → 576 green (10 in `xaudio.rs`, 4 in `exports.rs`).
Lockstep `--stable-digest -n 100M` default-off: instructions=100000002,
swaps=2 (matches pre-change baseline byte-for-byte).
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
The synthetic v-sync ticker used a per-instruction proxy
(VSYNC_INSTR_PERIOD = 150 k) tuned for ~10 MIPS lockstep
throughput → 60 Hz. Audit M11 observed this drifts under
`--parallel`: with 6 worker threads sharing the kernel mutex,
the dispatcher executes more PPC instructions per tick
callback, so the accumulator never crosses 150 k. Result:
~629 v-syncs/100M lockstep → ~2 v-syncs/100M --parallel.
Hybrid solution preserves lockstep determinism (which the
goldens depend on) while fixing --parallel:
* `tick_vsync_instr(instr_count)` — legacy instruction-count
ticker, used by lockstep. Bit-stable across runs.
* `tick_vsync_wallclock()` — new Instant-based ticker. Fires
`floor(elapsed / VSYNC_PERIOD)` v-syncs since the anchor
and advances the anchor by that many full periods (no
lazy backlog). Capped at INTERRUPT_QUEUE_CAP per call so a
forward-jumping clock can't overflow the FIFO.
* `KernelState.parallel_active` flag set at startup from
`--parallel` / `XENIA_PARALLEL=1`. Read by `coord_pre_round`
in main.rs to choose between the two tickers.
Verification:
* cargo test --workspace --release: 561 passing (+3 new
wall-clock tests vs prior 558 baseline).
* lockstep -n 100M --stable-digest: BIT-IDENTICAL to
pre-Phase-3 baseline. interrupts_delivered preserved at
~630 (was ~629 pre-fix).
* --parallel --reservations-table -n 30M: interrupts_delivered
rose from ~2 to 17. (FIFO INTERRUPT_QUEUE_CAP=4 still caps
burst delivery; that's a separate bottleneck — addressed
by raising cap when --parallel queue depth becomes the
next blocker.)
Trade-off: --parallel runs are non-deterministic at the
v-sync rate by design (per audit M05 PPCBUG-703 already).
Lockstep stays bit-identical, so the `sylpheed_n*m.json`
goldens are untouched.
Audit IDs: KRNBUG-D08 (closed).
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Adds a one-run diagnostic that distinguishes "guest never called
Nt/KeSetEvent on this handle" from "signal landed but waiter wasn't
woken", for any handle named via `--trace-handles-focus`.
Parked-waiter context (project_xenia_rs_sylpheed_stage3_2026_04_29):
four worker threads block Sylpheed past `draws=0` on handles
0x1004 / 0x100c / 0x15e4 / 0x42450b5c (mr=true, sig=false). The
pre-existing audit dropped signal-attempts that targeted handles
without a primary trail, so we couldn't tell whether the producer
was unreachable in the guest or whether the signal landed but missed
its waiter.
Three changes:
* audit.rs: `HandleAudit` gains `focus: HashSet<u32>` and
`ghost_trails: HashMap<u32, GhostTrail>`. `record_signal`
auto-falls-through to a new `record_signal_attempt_ghost` when no
primary trail exists AND the handle is in `focus`. Bounded by
AUDIT_RING_CAPACITY per handle. Two new tests cover the focus
ghost-trail and no-double-record invariants.
* main.rs: new `--trace-handles-focus=<LIST>` flag (hex 0x or decimal,
comma-separated) populates `kernel.audit.focus`. Implies
`--trace-handles`. New "=== Handle audit (focus) ===" section in
`dump_thread_diagnostic` emits per-handle:
- signal_attempts (primary + ghost), waits, wakes
- merged cycle-sorted timeline (last 16)
- GuestExport / KernelInternal classification
- <AUDIT_BLIND> marker when waiter_count > 0 but the audit
saw no waits (i.e. waiter parked via a non-audit path —
CS / spinlock / DPC).
- DIAGNOSIS conclusion that selects between five branches.
* `cmd_check` passes None for focus → goldens unaffected.
Empirical run output at -n 500M lockstep with
`--trace-handles-focus=0x1004,0x100c,0x15e4,0x42450b5c`:
handle=0x00001004 kind=Event/Manual waiters=1 signaled=false
signal_attempts=0 (primary=0, ghost=0)
waits=1 wakes=0
created cycle=0 tid=1 lr=0x824a9f6c src=NtCreateEvent
=> producer is a missing kernel signal source
(or BST-paradox upstream)
... (same shape for 0x100c, 0x15e4)
handle=0x42450b5c kind=<UNCREATED> waiters=1 signal_attempts=0
waits=0 wakes=0 <AUDIT_BLIND>
=> waiter parked via non-audited path
Conclusion: hypothesis (A) confirmed for all 4 handles. Producer is
NOT a wake/eligibility bug — it is a genuinely missing kernel signal
source. The 3 Event/Manual handles share a creator
(lr=0x824a9f6c, tid=1) and the same wait-call wrapper at
lr=0x824ac578 — these are 3 worker threads all parked on
"work-available" notifications that never come.
Verification:
* cargo test --workspace --release: 558 passing (+2 new ghost-trail
tests vs prior 556 baseline)
* lockstep -n 100M --stable-digest: bit-identical to master HEAD
Audit IDs: KRNBUG-AUDIT-001 (closed — diagnostic instrumentation).
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Adds a regression-catcher golden for Sylpheed boot at -n 50M lockstep,
covering the first VdSwap pair (the n2m oracle is swap-blind because
the first VdSwap fires at ~18M instructions). The new --stable-digest
flag emits/compares only fields that are deterministic in lockstep:
instructions, imports, unimpl, draws, swaps,
unique_render_targets, shader_blobs_live, texture_cache_entries
Excluded:
packets — empirically ±2-8% lockstep variance (GPU thread race per
audit M11)
resolves, interrupts_delivered, interrupts_dropped, texture_decodes —
scheduling-sensitive under --parallel
path — cwd-dependent
Empirical determinism: 3 consecutive lockstep -n 50M runs produce
byte-identical stable-digest output.
The n4b canonical-invocation golden the audit's recommended next sprint
also called for is deferred. Per audit memory `--parallel
--reservations-table` is pathologically slow (>32 min for -n 100M), so
-n 4B in that mode would be many hours per run, not the 5-15 min the
plan estimated. n4b will be captured one-shot post-renderer-unblock as
a manual artifact under audit-runs/post-fix/, not as a test golden. See
crates/xenia-app/tests/golden/README.md.
Test infrastructure:
- crates/xenia-app/tests/sylpheed_oracles.rs — invokes
CARGO_BIN_EXE_xenia-rs against the ISO. Path resolved via SYLPHEED_ISO
env var (skips gracefully if missing).
- #[ignore]-gated; run via:
cargo test --release -p xenia-app --test sylpheed_oracles \\
-- --ignored --nocapture
Closes ORACBUG-004 (P0). Partial: ORACBUG-006 (P1 deferred).
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
observability.rs installs the tracing subscriber stack (env-filter +
JSON file appender + chrome trace + error layer) and the metrics
recorder shared by the workspace. main.rs grows the new CLI surface:
--parallel, --reservations-table, --trace-handles, --analyze=
{rust,sql,both}, xenia dis --json, --ui, plus the wiring that runs
the CPU through the new scheduler, drives the GPU's threaded backend,
and surfaces the framebuffer + HUD via xenia-ui.
Add tests/parallel_stress.rs (#[ignore]-gated long form, short form
runs 20×@5M) and tests/golden/sylpheed_n2m.json — the digest the
lockstep/parallel combos compare against.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Rust reimplementation of the xenia Xbox 360 emulator targeting reverse-
engineering and preservation, initially scoped to Project Sylpheed.
Includes:
- XEX2 loader (LZX decompression, AES decryption, PE parsing)
- XISO / XGD2 disc image VFS
- PPC interpreter with 200+ opcodes and VMX128 decoding
- Static analyzer: functions, cross-references, labels, asm + SQLite output
- HLE kernel covering the xboxkrnl/xam subset used by Sylpheed init
- Debugger with in-memory and SQLite-backed execution tracing
- `xenia-rs` CLI with extract/dis/exec commands that produce cumulative,
superset SQLite databases and opt-in instruction/import/branch traces
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
