[tor-bugs] #2746 [Tor Relay]: libevent2 problems on CCC tor servers

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#2746: libevent2 problems on CCC tor servers
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 Reporter:  kaner      |          Owner:                     
     Type:  defect     |         Status:  new                
 Priority:  normal     |      Milestone:                     
Component:  Tor Relay  |        Version:  Tor: 0.2.2.22-alpha
 Keywords:             |         Parent:                     
   Points:             |   Actualpoints:                     
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Comment(by nickm):

 Is this really with .22-alpha?  And which libevent2 version?

 The error implies that kevent() in libevent's kqueue.c is giving an error
 "EBADF", which implies that we are getting a failure because "the
 specified file descriptor is invalid."  (See kqueue.c , in function
 kq_dispatch.)

 That's quite weird!  If a particular file descriptor that we were passing
 to kevent were bad, we would (in theory) be getting that error passed back
 in events[i].flags, not set with an error when kevent returns.  So this
 sounds to me as if freebsd were complaining that the kqueue fd (the one
 that was returned from kqueue()) was bad!

 Possibilities that come to mind if that analysis is right:
   * Bug in freebsd. (not so likely -- the freebsd kqueue code is usually
 pretty solid)
   * Something closed the kqueue fd.
   * Something corrupted the libevent kqop structure, so that it's looking
 at the wrong fd.

 Reasons why that analysis might be wrong.
   * Maybe I am misunderstanding why kevent() would give EBADF.
   * Maybe there is a bug in the error-reporting code, and the error with
 which kevent is failing is not really EBADF.

-- 
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/2746#comment:5>
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