Why /dev/kmsg was deleted from cygwin1.dll in git?

Corinna Vinschen corinna-cygwin@cygwin.com
Wed Jul 4 14:52:00 GMT 2018


On Jul  4 22:01, Takashi Yano wrote:
> Hi Corinna,
> 
> On Wed, 4 Jul 2018 12:54:20 +0200
> Corinna Vinschen wrote:
> > On Jul  4 04:44, Takashi Yano wrote:
> > > Why was /dev/kmsg deleted from cygwin1.dll in git?
> > > Due to this change, syslogd in inetutils package no longer works.
> > 
> > /dev/kmsg doesn't really give any useful information.  It was never used
> > for more than some exception information, but it required a complete
> > fhandler class on its own.  I wanted to get rid of the useless code.
> 
> I looked into this problem and I realized that the real cause is not the absence of /dev/kmsg but old codes in the connect_syslogd() function in
> syslog.cc.
> 
> I removed these codes and confirmed that syslogd works again.

Hang on.  /dev/kmsg was implemented using a mailslot and it was never
accessible via the syslog(3) interface.  The code you removed has
nothing to do with /dev/kmsg.

What the code does is to check if we have a listener on the /dev/msg UDP
socket, otherwise log data may get lost or, IIRC, the syslog call may
even hang.  So removing this code sounds like a bad idea.

Can you please explain *why* removing this code helps and what happens
if syslogd is not running after removing the code?


Thanks,
Corinna

-- 
Corinna Vinschen                  Please, send mails regarding Cygwin to
Cygwin Maintainer                 cygwin AT cygwin DOT com
Red Hat
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