[all-commits] [llvm/llvm-project] 0984b8: tsan: don't leave unmapped hole in non-app memory

[Dmitry Vyukov via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 0984b8de0b0d5d178a8e6e5de1eb89f29493a89e
      https://github.com/llvm/llvm-project/commit/0984b8de0b0d5d178a8e6e5de1eb89f29493a89e
  Author: Dmitry Vyukov <dvyukov at google.com>
  Date:   2021-02-17 (Wed, 17 Feb 2021)

  Changed paths:
    M compiler-rt/lib/tsan/rtl/tsan_interceptors_posix.cpp
    M compiler-rt/lib/tsan/rtl/tsan_rtl.cpp
    A compiler-rt/test/tsan/mmap_lots.cpp

  Log Message:
  -----------
  tsan: don't leave unmapped hole in non-app memory

If an app mmaps lots of memory, a user mmap may end up
in the tsan region for traces. Shadow for this range
overlaps with shadow for other user regions.
This causes havok: from false positives to crashes.
Don't leave unmapped holes in the traces region.

Reviewed-in: https://reviews.llvm.org/D96697