[all-commits] [llvm/llvm-project] b63744: tsan: capture shadow map start/end on init and reu...

[Than McIntosh via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: b6374437af39af66896da74a1dc1b8a0ece26bee
      https://github.com/llvm/llvm-project/commit/b6374437af39af66896da74a1dc1b8a0ece26bee
  Author: Than McIntosh <thanm at google.com>
  Date:   2022-07-26 (Tue, 26 Jul 2022)

  Changed paths:
    M compiler-rt/lib/sanitizer_common/sanitizer_common.h
    M compiler-rt/lib/sanitizer_common/sanitizer_win.cpp
    M compiler-rt/lib/tsan/go/build.bat
    M compiler-rt/lib/tsan/rtl/tsan_platform.h
    M compiler-rt/lib/tsan/rtl/tsan_rtl.cpp
    M compiler-rt/lib/tsan/rtl/tsan_rtl.h

  Log Message:
  -----------
  tsan: capture shadow map start/end on init and reuse in reset

Capture the computed shadow begin/end values at the point where the
shadow is first created and reuse those values on reset. Introduce new
windows-specific function "ZeroMmapFixedRegion" for zeroing out an
address space region previously returned by one of the MmapFixed*
routines; call this function (on windows) from DoResetImpl
tsan_rtl.cpp instead of MmapFixedSuperNoReserve.

See https://github.com/golang/go/issues/53539#issuecomment-1168778740
for context; intended to help with updating the syso for Go's
windows/amd64 race detector.

Differential Revision: https://reviews.llvm.org/D128909