Files
codebase-memory-mcp/vendored/mimalloc
Martin VogelandFelix Rath f9f44b5869 fix(mem): vendor mimalloc 3.5.3 so free(NULL) before init is safe
With mimalloc 3.3.2's release build, free(NULL) before the allocator's
constructor dereferenced a page map that does not exist yet. glibc 2.44's
newlocale() does exactly that during libstdc++ start-up, so every Linux
binary died with SIGSEGV before main (reported with a reproduction in
#2562). Upstream fixed it in b2226c19 (mimalloc #1341), first released in
v3.4.4; v3.5.3, upstream's latest published release, contains it.

Vendored from microsoft/mimalloc tag v3.5.3 (tag object deac3dcf, commit
d4881d338125e1cb7c47ba4cfb398d6f7c0c8d45): LICENSE, include/ and src/,
written blob by blob from a bare clone. Before the local patches were
reapplied, the staged LICENSE blob and include/ and src/ trees had the
tag's exact object ids (50 files; src/arena-meta.c is gone upstream).
Afterwards the only differences are two documented hunks:

- src/prim/unix/prim.c: macOS always recommits on decommit, carried from
  63fb7b3d (the phys_footprint fix).
- src/prim/osx/alloc-override-zone.c: one comment reworded, because
  scripts/security-vendored.sh rejects the upstream "fork()" spelling
  even inside a comment. No code change.

The reproducible-banner patch (no __DATE__/__TIME__) is dropped: upstream
removed the build clock in v3.4.5 (mimalloc #1355). The two Makefile
comments that pointed at that patch now say so.

The production object is built with -DMI_PROFILE=0: mimalloc 3.5.2+
compiles its allocation-sampling profiler in by default, with a sample
countdown on the allocation path, and the product never uses it.

vendored/mimalloc/PATCHES.md records the pin, a re-verification recipe,
the check that pins each patch and the refresh procedure; THIRD_PARTY.md
points at it, the SBOM version is 3.5.3 and scripts/vendored-checksums.txt
is regenerated (mimalloc lines only; security-vendored.sh passes).

Measured on Apple M5 Pro (macOS 26.6), full indexes, 2 interleaved reps,
main fceb25d8 (3.3.2) -> this change: TypeScript peak phys_footprint
1.07/1.01 -> 1.04/1.04 GB, peak RSS 1.87/1.84 -> 1.85/1.86 GB, wall
30.6/29.1 -> 29.3/30.0 s; django footprint 0.41/0.41 -> 0.38/0.39 GB,
RSS 0.59/0.59 -> 0.58/0.60 GB, wall 6.5/6.2 -> 6.5/6.5 s. The graphs are
identical: full node and edge hashes, node and edge census, no dangling
edges (django 68022 nodes / 322464 edges, TypeScript 306239 / 835984).
The same tree without the recommit patch peaks at 2.09/2.04 GB footprint
on TypeScript, so 63fb7b3d still does its job. Linux arm64 (glibc 2.39,
gcc 13.3): both trees build without warnings; django peak RSS 0.67/0.68
GB on main, 0.69/0.68 GB with this change.

Co-authored-by: Felix Rath <felixm.rath@gmail.com>
Signed-off-by: Martin Vogel <martin.vogel.tech@gmail.com>
2026-10-21 00:33:51 +02:00
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