Map made every singly mapped section page private resident memory. A JIT
or shm_open section is file backed and committed: its bytes live in the
file, and its alias descriptors map duplicated handles, which the physical
page slots do not match, so a resident copy diverged from the file, and
committing its view on a demote failed with access denied
(guest_jit_shared_memory). Only direct memory backings, mapped through the
new GuestArenaMapDirect, now become resident; other sections keep main's
shared views. Shared pages are committed only while their section page is
reserved, as on main.
The socket host write tests map their direct memory a second time, so the
write-protected shared path they check is still the one they exercise.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01V1W4jdNSKTV7xwuS6xQPJV
A direct memory page mapped at one guest address now lives in private
MEM_WRITE_WATCH memory at that address, and its writes are collected with
GetWriteWatch like flexible memory: no fault is raised. A page mapped at a
second address moves its whole resident run into the section, behind a
read-only fence while it is copied, and every address becomes a view of it,
tracked by write protection. Unmapped resident pages that are not blank are
kept in a private reservation until they are mapped again, not in the
section.
Ported onto main's 4 KiB subpage tracking of shared views: resident runs
keep a per-page collected bit and enter the fresh ranges, so Fresh and
Armed collections select them like shared views; a demoted run carries its
collected bits into the views and reports every page once. MapAlias throws
through refuse() when a resident run extends outside the aliased range, and
the caller keeps main's fallback.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01V1W4jdNSKTV7xwuS6xQPJV
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