[tor-bugs] #18306 [Tor]: Avoid using tor_assert before the logging system is fully initialised

[Tor Bug Tracker & Wiki]

#18306: Avoid using tor_assert before the logging system is fully initialised
------------------------+--------------------------------
     Reporter:  teor    |      Owner:
         Type:  defect  |     Status:  new
     Priority:  Medium  |  Milestone:  Tor: 0.2.9.x-final
    Component:  Tor     |    Version:
     Severity:  Normal  |   Keywords:
Actual Points:          |  Parent ID:
       Points:          |    Sponsor:
------------------------+--------------------------------
 In #18241, we discovered that an assertion failure that occurs before or
 during the initialisation of the logging system causes an infinite loop.

 We need to check tor and the tools for these kinds of issues.

 In particular, the logging system initialises the log mutex.
 tor_mutex_init() can still call tor_assert if it fails, so the possibility
 of this stack overflow still exists when we're initialising the log mutex
 itself.

 Now these kinds of failures don't happen very often, and if they do, it's
 unlikely tor would ever launch. But it would be better to use
 `fprintf(stderr, ...);` in these circumstances so that users can see the
 actual log message.

--
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/18306>
Tor Bug Tracker & Wiki <https://trac.torproject.org/>
The Tor Project: anonymity online