[all-commits] [llvm/llvm-project] d31b2d: tsan: add debugging code for ptrace test failures

[Dmitry Vyukov via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: d31b2dc235f1b1eff27c553012520792b7a0eb47
      https://github.com/llvm/llvm-project/commit/d31b2dc235f1b1eff27c553012520792b7a0eb47
  Author: Dmitry Vyukov <dvyukov at google.com>
  Date:   2021-10-29 (Fri, 29 Oct 2021)

  Changed paths:
    M compiler-rt/lib/tsan/rtl/tsan_interceptors.h
    M compiler-rt/test/sanitizer_common/TestCases/Linux/ptrace.cpp

  Log Message:
  -----------
  tsan: add debugging code for ptrace test failures

Debugging of crashes on powerpc after commit:
c80604f7a3 ("tsan: remove real func check from interceptors")
Somehow replacing if with DCHECK leads to strange failures in:
SanitizerCommon-tsan-powerpc64le-Linux :: Linux/ptrace.cpp
https://lab.llvm.org/buildbot/#/builders/105
https://lab.llvm.org/buildbot/#/builders/121
https://lab.llvm.org/buildbot/#/builders/57

The hypothesis is that something writes out-of-bounds
into pt_regs on stack and that corrupts internal tsan state.

Reviewed By: melver

Differential Revision: https://reviews.llvm.org/D112703