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.
bef9793aec