Comparing the parent PID with 1 isn't sufficient to ensure the parent is alive,
because of prctl(PR_SET_CHILD_SUBREAPER, ...). Compare with the real parent's
recorded PID instead.
llvm-svn: 192295
The tracer thread in StopTheWorld could wait on a mutex forever if the parent
process died before unlocking it. Use PR_SET_PDEATHSIG so that the parent would
kill the child in this scenario.
llvm-svn: 192210
Add a wrapper for the clone syscall for use in StopTheWorld. We
implement it only for x86_64, so stop building StopTheWorld for other platforms
(no one uses it outside x86_64 anyway).
See https://code.google.com/p/address-sanitizer/issues/detail?id=214 for why we
can't use the glibc clone() wrapper.
llvm-svn: 189753
Handle calls to Die() from the tracer thread. Fixes a bug where a CHECK
could fail in the tracer thread, resulting in a call to AsanDie. The tracer
thread then exited and the parent process continued execution despite its
address space being in an unusable state.
llvm-svn: 189216