[PATCH] tsan: fix PTRACE_ATTACH handling during stop-the-world

[Dmitry Vyukov]

================
Comment at: lib/sanitizer_common/sanitizer_stoptheworld_linux_libcdep.cc:114
@@ +113,3 @@
+    // continue to wait for stopping, because the thread is not stopped yet.
+    // We do ignore delivery of SIGSTOP, because we want to make stop-the-world
+    // as invisible as possible.
----------------
earthdok wrote:
> We do actually want to stop the threads, though.
> 
> I think you misunderstood this part:
> 
> > The usual practice is to reinject these signals until SIGSTOP is seen, then suppress SIGSTOP injection.
> 
> This is "usual practice" for when you want the threads to keep running.
Why do you think that my code does not stop threads?
Or what do you suggest? I don't understand.

http://reviews.llvm.org/D7723

EMAIL PREFERENCES
  http://reviews.llvm.org/settings/panel/emailpreferences/