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orca/docs/reference
Orca Worker bc77c53a57 fix(windows): drop the PEB fallback and detect the unpatched prebuilt
Review of #17886 found three ways the reader could still perform, or silently
resume, the primitive it exists to remove.

The class-missing latch was a permanent, process-wide, one-way downgrade back
to the PEB read, and any single target returning STATUS_INVALID_INFO_CLASS /
NOT_SUPPORTED / NOT_IMPLEMENTED could trip it. On an EDR-hooked ntdll -- the
entire premise of this change -- a hook that does not recognise class 60 would
have restored PROCESS_VM_READ plus three ReadProcessMemory per pid per scan for
the life of the process, unobservably, on precisely the machines this was
written for. The fallback is deleted rather than guarded: GetProcessCommandLine
now returns false and leaves the command line empty, which callers already
handle, so the addon imports no ReadProcessMemory at all.

That absence is what makes the property checkable on the artifact. The
published 0.8.0 tarball ships a loadable prebuilt built from unpatched source;
it is node-addon-api, so a bare require() accepts it, allowBuilds is false and
CI installs with --ignore-scripts, and a rebuild that soft-exits on a Windows
file lock leaves it in place. Source-text guards could never see it.
windowsProcessTreeAddonReadsProcessMemory() checks the compiled binary instead,
and is wired into the install check, the rebuild, and the relay build.

The repair itself never worked: `git apply` run inside a work tree prefixes
patch paths with the cwd-relative prefix, skips what does not match, and exits
0, so the branch always fell through to its own post-check throw. The package
dir is always under the project root, while the fixture that covered it was in
%TEMP%, outside any repo. Blinding git with GIT_DIR fixes it, and the test now
runs inside a real work tree.

Also from review: bounds-check the returned UNICODE_STRING against the
allocation (not the size the second query clobbers) and cap the probe so a
bogus length cannot bad_alloc a whole scan; test NT_SUCCESS explicitly; value-
initialize ProcessInfo, which left `memory` as stack garbage -- measured, 82
processes reported the same bogus working set; and correct a comment in
windows-process-table.ts that still described the command line as a PEB read.

Re-measured on Windows 11 (543 processes): ReadProcessMemory 1128 -> 0, with
the symbol absent from the import table so the IAT hook finds no slot to
count; desired access 0x0410 -> 0x1000 on all 543 opens; p50 13.5 -> 12.3ms;
405/405 command lines byte-identical including a 24,087-character quoted
non-ASCII argv and a WOW64 target; 3 processes recovered only by the new path,
0 only by the old.
2026-09-01 01:38:50 -07:00
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