Re: [Fwd: [Bug libc/671] New: It appears syslog can go into deadlock when it receives a signal where the signal handler also syslogs]

[Wesley D Craig <wes@xxxxxxxxx>]

On 15 Jan 2005, at 21:32, Brett Lomas wrote:
> FYI, I just reported this bug, because I was seeing it in the cosign
> daemon when using the replication and stressing it.
>
> I have removed all of the sysloging in pusherchld to stop pusherparent
> from going into deadlock, at least until i hear back on this.

We noticed this problem some time ago in another project (radmind) and  
have been fixing all of our projects since.  The CVS HEAD version of  
cosign has fixed the problem by removing all "interesting" code from  
all signal handlers.  See:

	http://cvs.web.itd.umich.edu/horde/chora/cvs.php?f=cosign/daemon/ 
pusher.c

Revision 1.35.  BTW, I don't think this is a bug in libc.  See:

	http://www.opengroup.org/onlinepubs/009695399/functions/sigaction.html

"Application Usage."  There is a specific prohibition against calling  
non-reentrant functions from a signal handler.  Examples of  
non-reentrant functions include malloc/free and stdio.  While syslog is  
not specifically mentioned, syslod is not required to be reentrant, and  
it works an awful lot like printf.

:wes