Cesarus85--mjolnir-vr/docs/object_matching_logs/libcmt_malloc_obj.md

libs/libcmt/malloc.obj exact-match ledger

This fresh atomic lane starts from authoritative campaign commit fc8e1b07. Before editing, the object was confirmed MISSING at index 802, unparked, absent from all prior object logs, refs, and worktrees, and free of active peer ownership.

Plain-English behavior

malloc passes the requested byte count and the process-wide new-handler mode to _nh_malloc. That retry routine rejects requests too large for the CRT, tries the heap, and, after failure, invokes the installed C++ new handler when enabled. A successful handler causes another allocation attempt.

_heap_alloc performs the actual system call. A zero-byte request becomes one byte. Legacy CRT heap modes round requests to a 16-byte paragraph; the system heap does not. It then allocates from the process heap without zero-filling.

Primary provenance and strict inventory

The exact XDK 3911 member obj\i386\malloc.obj was extracted before source work. CodeView identifies ordinary Microsoft C source d:\xbox-finalfre\private\sdktools\crt\crtw32\heap\malloc.c. The matching 1991-2001 Microsoft source was also recovered from pinned Easy-Build-2k commit 36fce23389e43918faf4cd88688c64aa2668ff8f. January bytes remain authoritative.

Archive and January are independently strict-equal for all runtime sections, and the object owns no data:

Function	Size	Relocs	Normalized SHA-256
_malloc	18	2	7f388340df849960003a441cc927c3ded189f49d9ea02af2e49fdd7ade73df0a
__nh_malloc	44	2	dbb3e472b55752a4522ce5ad849d314a7da2b8c9f63a5cacc72522d5c98b0d0e
__heap_alloc	39	3	89e1a6a35c8604b033bdca1b6363d749a67000283dd305ad7b32aa9c3889e828

All seven relocation addresses, types, destinations, and addends match. They reference _newmode, _nh_malloc, _heap_alloc, _callnewh, __active_heap, GetProcessHeap, and RtlAllocateHeap exactly once each.

Measured source experiments

ID	One changed source factor	Strict result	Decision
E01	Microsoft allocator behavior with the redundant maximum-size check simplified out of the retry loop	_malloc and _heap_alloc exact; _nh_malloc 45/44 bytes, 2/2 relocs in reversed call order	Rejected
E02	Restore Microsoft's inner size <= HEAP_MAXIMUM_REQUEST guard inside the retry loop	All three functions exact, including relocation order and identity	Accepted

The repeated check is readable defensive CRT logic, not a codegen-only dummy. It keeps the retry path locally valid even though the entry guard has already excluded oversized requests. Preserving it also reproduces VC7's original loop layout.

Strict gates and house/Berth audit

The accepted source uses size_t, named heap modes, a named maximum-request limit, and typed system API declarations. It mirrors the Microsoft algorithm rather than the disassembly. It contains no assembly, volatile, forced inlining, undefined behavior, byte forcing, compiler pragma, alignment trick, flag change, comparator exception, or relocation waiver.

No independently actionable January bug was established. In particular, returning a distinct non-null allocation for a zero-byte request is deliberate historical CRT behavior and is preserved, not marked as a defect.

The forced object rebuild and both full builds passed. The semantic report evaluated 3,594 functions in 465 units, accepted 3,510 exact functions, and reported zero unit errors. The admission audit found no new candidate, contradiction, or revocation for libs/libcmt/malloc. Progress reached 364/833 complete objects overall and 97/212 libcmt objects; libcmt has 157/476 exact functions and 11,422/55,015 exact code bytes. All 179 tests pass. JSON, prohibited-construct, and diff checks are clean. The clean-commit regression snapshot/check classifies all three functions as still_exact, with no changed nonexact functions, failures, or warnings.