Revoke a checked arena page with mprotect behind the registry and check
that the stored answer comes back, so the test fails without the cache.
Pass the gpu argument that GuestAllocations::Mutation::Add and Protect
now take.
describePages stored the whole VMA that PROCMAP_QUERY or /proc/self/maps returned. Linux merges adjacent
anonymous mappings with equal flags, so an arena VMA can span GiBs, and the first table miss inside it after
an invalidation rewrote every page of it. Only the pages of the request, rounded out to whole pages, are
stored now, as #1791 describes.
When the guest arena is available, RunUnmappedGapTests checks that a check stores no pages outside its
range, and that protecting and unmapping through the registry clears the stored pages. The registry checks
follow the test on the perf/linux-page-cache branch linked from #1791.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
The registry records whether a range was mapped or protected with GPU
access (0x10/0x20), and an address-based build leaves out ranges without
it, as the console's GPU page tables do. The main image is registered
without GPU access; the title's own mprotect with GPU bits adds it.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Release the registry mutex while yielding for an outstanding lease even before a GPU pin waiter is registered. This lets the lease holder finish a nested allocation lookup and release its lease instead of deadlocking against an unmap.
Validation: the deterministic concurrent unmap/lookup regression fails at the lease deadline before the fix and passes after it. Graphics and guest-memory CTests pass. Live Skyrim stacks captured this cycle in a compute upload flushing a storage texture.
AI-assisted implementation.
Without VirtualQuery, a range no cached page table covers is looked up
line by line in /proc/self/maps. A cursor in a gap between mappings never
matched a line, so the scan parsed the whole file and then reported the
rest of the range unmapped, including mapped pages after the gap. The
scan now stops at the first mapping above the cursor, reports the gap up
to it as inaccessible and continues from there, as the VirtualQuery path
does with a free region.
PPSA21564 queries near-null addresses (0x18, 0x30, 0x58) about 1500 times
a second during resource capture; each of those parsed the whole maps
file (about 5700 lines here) instead of stopping at the first mapping.
Tests: agc_driver_graphics_tests describes three host pages with the
middle one unmapped as two ranges, a query that starts in the gap as the
page after it, and a near-null address as inaccessible.
As on FreeBSD, a munmap range covering more than one registered allocation (or gaps between them)
is unmapped allocation by allocation instead of throwing "unmap crosses allocation boundaries".
GTA V unmaps such ranges in its Story Mode prologue.
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
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