[all-commits] [llvm/llvm-project] be41a9: tsan: fix deadlock with pthread_atfork callbacks

[Dmitry Vyukov via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: be41a98ac222f33ed5558d86e1cede67249e99b5
      https://github.com/llvm/llvm-project/commit/be41a98ac222f33ed5558d86e1cede67249e99b5
  Author: Dmitry Vyukov <dvyukov at google.com>
  Date:   2020-03-21 (Sat, 21 Mar 2020)

  Changed paths:
    M compiler-rt/lib/tsan/rtl/tsan_rtl.cpp
    A compiler-rt/test/tsan/pthread_atfork_deadlock2.c

  Log Message:
  -----------
  tsan: fix deadlock with pthread_atfork callbacks

This fixes the bug reported at:
https://groups.google.com/forum/#!topic/thread-sanitizer/e_zB9gYqFHM

A pthread_atfork callback triggers a data race
and we deadlock on the report_mtx. Ignore memory access
in the pthread_atfork callbacks to prevent the deadlock.