[all-commits] [llvm/llvm-project] 720769: [tsan] Lazily call 'personality' to minimize sandb...

[Thurston Dang via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 720769de9f7531a79013b7e14ca808bdfc8fc258
      https://github.com/llvm/llvm-project/commit/720769de9f7531a79013b7e14ca808bdfc8fc258
  Author: Thurston Dang <thurston at google.com>
  Date:   2024-01-25 (Thu, 25 Jan 2024)

  Changed paths:
    M compiler-rt/lib/tsan/rtl/tsan_platform_linux.cpp

  Log Message:
  -----------
  [tsan] Lazily call 'personality' to minimize sandbox violations (#79334)

My previous patch, "Re-exec TSan with no ASLR if memory layout is incompatible on Linux (#78351)" (0784b1eefa36d4acbb0dacd2d18796e26313b6c5) hoisted the 'personality' call, to share the code between Android and non-Android Linux. Unfortunately, this eager call to 'personality' may trigger sandbox violations on non-Android Linux.

This patch fixes the issue by only calling 'personality' on non-Android Linux if the memory mapping is incompatible. This may still cause a sandbox violation, but only if it was going to abort anyway due to an incompatible memory mapping.

(The behavior on Android Linux is unchanged by this patch or the previous patch.)