Calling symbolization directly from stopTheWorld was causing deadlock.
For libc dep systems, symbolization uses dl_iterate_phdr, which acquire a
dl write lock. It could deadlock if the lock is already acquired by one of
suspended.
Reviewed By: vitalybuka
Differential Revision: https://reviews.llvm.org/D146990
It was failing because of size_t being unknown. I was going to just pull
in stddef.h, but the callback using size_t is only used for Linux and
NetBSD, so limit its definition to those platforms as well.
Wrapping stopTheWorld in dl_iterate_phdr acquire dl_load lock before
calling the function. Acquiring dl_load, allocator and thread registry
locks before calling stopTheWorld ensures no other threads are holding
that locks, we can safely suspend them and reenter in tracer thread.
LockStuffAndStopTheWorld's logic here is same as lsan's implementation
of this function.
Reviewed By: vitalybuka
Differential Revision: https://reviews.llvm.org/D146990
