A shared mapping is a view of a file section created on the descriptor's
handle, read-write when the descriptor is, otherwise read-only. A private
mapping is a copy of the file read at mmap, as POSIX allows. Anonymous
shm_open objects and JIT shared memory descriptors are temporary files on
Windows, so mmap now maps them too (it failed with EOPNOTSUPP before).
mprotect of a mapped view above the view's protection fails with EACCES
before any bookkeeping changes. The cases Windows cannot represent are
listed in the libkernel debt.
Dusklight (PPSA99305) uses SQLite in WAL mode, which maps its -shm file.
On Windows main f0634088b every start logged "Failed to start
transaction: disk I/O error" for its Dawn and pipeline caches (3 of 3
runs); with this change the caches initialise and their WAL files fill
(4 of 4 runs). The title reaches its menu either way.
A shared mapping may end inside the 16 KiB page that holds the end of
the file, as POSIX mmap allows: the view ends with the file's last 4 KiB
host page, which Windows zero-fills past the end, the rest of the guest
page is private zero pages, and the file never grows. A mapping that
reaches a whole page past the end still fails with EOPNOTSUPP.
PS5LM Plus (PPSA99581) loads its model with llama.cpp, which maps the
whole GGUF file shared and read-only. With a 491,400,032-byte model,
Windows main 5de7a46e0 and this change without the last page logged
"llama_model_load: error loading model: mmap failed: Operation not
supported" (3 of 3 runs); now the model loads and the completion of
"The capital of France is" starts with " Paris" (3 of 3 runs).
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Complete the object lifecycle through guest mapping and unlink APIs, and
preserve FreeBSD shared-object size and seek rules across scalar, vector
and asynchronous descriptor writes. Pin descriptors during operations and
coordinate size-sensitive operations across cooperating emulator processes.
Constraint: Linux host support with existing dependencies and allocation tracking
Rejected: Bare descriptor registry | close, duplication and reuse invalidate identity
Rejected: Per-object OFD locks | forked descriptors share the same lock description
Confidence: high
Scope-risk: moderate
Directive: Keep guest resize, truncating open and bounded writes under the same namespace guard
Tested: Ten Linux runtime suites; focused shared-memory ASan/UBSan suite with warnings as errors
Not-tested: Windows build, PS5 hardware and title compatibility
Translate guest named-open flags and permissions to POSIX shared-memory descriptors. Bound guest names and use the existing digest implementation to keep a stable AnyPS5 namespace, including long names and internal slashes. Preserve anonymous and Windows behavior, and record the separate unlink and guest mapping gaps.
Constraint: Builds and tests run only through the enrolled 191 compute service.
Rejected: Direct Linux guest names | cannot represent FreeBSD internal slashes and 1023-byte names.
Tested: Source review and diff checks; baseline job100619 accepted, result retrieval currently times out.
Not-tested: Runtime verification pending on191; full build, Windows and titles.
Confidence: medium
Scope-risk: narrow
