Re: Handling __cxa_atexit(a,b,NULL)

[Joerg Sonnenberger <joerg%bec.de@localhost>]

On Thu, Nov 02, 2017 at 07:09:34PM +0100, Kamil Rytarowski wrote:
> TSan intercepts all atexit() and __cxa_atexit() calls and wraps them in
> setup_at_exit_wrapper(() into a new struct that preserves the original
> arguments "a" and "b" from __cxa_atexit() / "a" from atexit(). In case
> of intercepting atexit() calls we end up with __cxa_atexit(x,y,NULL). In
> libc we handle this variation in the same way as atexit(x) and drop the
> "y" argument.

It should be intercepting atexit separately and just providing its own
stack, followed by registering a pop-and-call handler via the real
atexit, i.e.:

   std::vector<h> atexit_stack;
   void my_cleanup(void) {
     h = atexit_stack.pop();
     h();
   }

   int intercepted_atexit(h) {
     atexit_stack.push(h);
     rv = real_atexit(my_cleanup);
     if (rv) atexit_stack.pop();
     return rv;
   }

Joerg