re: lib/47055: libc diagassert issues

[matthew green <mrg%eterna.com.au@localhost>]

The following reply was made to PR lib/47055; it has been noted by GNATS.

From: matthew green <mrg%eterna.com.au@localhost>
To: gnats-bugs%NetBSD.org@localhost
Cc: lib-bug-people%netbsd.org@localhost, gnats-admin%netbsd.org@localhost,
    netbsd-bugs%netbsd.org@localhost
Subject: re: lib/47055: libc diagassert issues
Date: Thu, 11 Oct 2012 16:53:50 +1100

 > (1) it calls syslog() blindly, so if an assertion happens in a program
 > that hasn't called openlog(), it ends up using uninitialized state in
 > syslog.c. The observable effect of this seems to be to issue syslog
 > messages with no hostname field; however, it could be (or become,
 > without much notice) a good deal worse.
 
 that shouldn't be a problem.  it sounds like a bug in syslog(3) itself.
 i've never seen any requirement for openlog(3) being necessary and indeed
 our documentation says:
 
    The openlog() function provides for more specialized processing of the
    messages sent by syslog() and vsyslog().
 
 > (2) it isn't thread-safe. It frob a global variable (diagassert_flags)
 > without locking. It also should probably be using syslog_r() rather
 > than syslog().
 
 probably.  (i don't think we had syslog_r() back when diagassert
 first appeared...)
 
 
 .mrg.