AUDIT-005's static attribution to sub_824ABA98 was wrong. The 0xC0000011
(STATUS_END_OF_FILE) at lr=0x824a97e4 traces to the NtReadFile call at
0x824a9810 inside sub_824A9710 — the cache-loader reads 1024 B from
offset 2048 of `\Device\Harddisk0\partition0`. Our synth-empty fallback
returned EOF (start_pos 2048 > size 0), so the function bailed via
RtlNtStatusToDosError before sub_824ABA98 was ever called.
Canary mounts partition0 to a NullDevice; `NullFile::ReadSync`
([null_file.cc:24-31](xenia-canary/src/xenia/vfs/devices/null_file.cc))
returns X_STATUS_SUCCESS with bytes_read=0 and never touches the
buffer. Sylpheed's caller pre-zeroes the 1024-byte stack buffer
(`memset(sp+208, 0, 1024)` at sub_824A9710 prologue), validates a
"Josh" magic on the first read, and falls back to the cache-recreate
path when the magic doesn't match.
The fix mirrors NullFile semantics: when the open synthesized a
zero-length file (`data.is_empty() && size == 0`), NtReadFile returns
SUCCESS with information=0 and the buffer untouched.
Effects (chain-of-effects verification at -n 500M):
- tests: 590 → 591 (added regression covering NullDevice semantics)
- lockstep: deterministic across 3 reruns (same instructions=100000010,
swaps=2)
- sylpheed_n50m golden re-baselined: instructions 50000004→50000000,
imports 407416→407362
- canary kernel-call diff: 10 → 7 missing exports
(XeCryptSha + XeKeysConsolePrivateKeySign + NtDeviceIoControlFile
now run; the cache-recreate path executes through to NtWriteFile)
- boot reaches silph::Silph::Impl::OnInit: 19 worker threads spawn
(was 6 before the fix)
- parked-handle 0x1004 still signal_attempts=0; the original 0x100c
and 0x15e0 are now <UNCREATED> because cascade walked past them and
the handle assignments shifted; new parked sites: 0x12fc/0x1600/
0x1040/0x10b8/0x15e8/0x1014/0x101c/0x10bc/0x1044
- draws=0 plateau persists; renderer is multi-causal blocked
Next blocker: per the canary-only diff, XamTaskSchedule + the cluster
of XAM exports (XamTaskCloseHandle, XamUserReadProfileSettings,
ObCreateSymbolicLink) and the post-thread-exit chain (ExTerminateThread,
KeReleaseSemaphore, KeResetEvent) are the next-up frontier.
Mirrors canary's cvars::avpack default (xam_info.cc:35) and Sylpheed's
accepted set {3,4,6,8} (xam_info.cc:250-251). With KRNBUG-XEX-001 having
flipped the priv-10 gate, XGetAVPack now reaches its caller in
sub_824AB578; returning 0x16 caused Sylpheed to abort the AV/crypto
block before XeCryptSha. Cascade walks one step (canary-only export
list 11 → 10); sub_824ABA98 is the next candidate.
Tests: 589 → 590. Goldens re-baselined (n50m: 50000005→50000004,
imports 407417→407416). Lockstep deterministic across 3 reruns at
-n 100M (instructions=100000010, import_calls=987686 +2.4×, swaps=2).
9-PC producer probe still 0×; parked handles 0x1004/0x100c/0x15e0
still signal_attempts=0.
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>
