[PATCH] D91106: [scudo][standalone] Correct min/max region indices

[Kostya Kortchinsky via Phabricator via llvm-commits]

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The original code to keep track of the minimum and maximum indices
of allocated 32-bit primary regions was sketchy at best.

`MinRegionIndex` & `MaxRegionIndex` were shared between all size
classes, and could (theoretically) have been updated concurrently. This
didn't materialize anywhere I could see, but still it's not proper.

This changes those min/max indices by making them class specific rather
than global: classes are locked when growing, so there is no
concurrency there. This also allows to simplify some of the 32-bit
release code, that now doesn't have to go through all the regions to
get the proper min/max. Iterate and unmap will no longer have access to
the global min/max, but they aren't used as much so this is fine.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D91106

Files:
  compiler-rt/lib/scudo/standalone/primary32.h

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