Re: Novel way to kill Apache

[Randy Terbush <ra...@zyzzyva.com>]

HPUX is also known to do this.

> It can happen on a lot of unixes in my experience.  In fact, all the ones
> that let you scribble into a running executable (i.e. they don't lock the
> executables).  That includes BSD*, linux, solaris, and IRIX.  But some of
> them probably ship with ld that unlink the old executable and create a new
> inode for the new one, (or gnu ld does this, I don't remember). 
> 
> Dynix/ptx won't let you rm a running executable, you have to rename it. 
> That's the only oddball I've ever worked with though.
> 
> Dean
> 
> On Thu, 6 Feb 1997, Ben Laurie wrote:
> 
> > If you build a program under Irix while it is running, it changes the code of
> > the running program, usually resulting in a crash! This comes as a big surprise
> > to me, since a) no other system I use does it, and b) its clearly trivial to
> > avoid. However, my contacts at SGI insist that this is expected and in no way
> > a bug. So, I wonder two things: does any other Unix do this (they claim they
> > do)? And should we have a note somewhere about it, or even change the Makefile
> > to do something like "mv httpd httpd-" (or "rm httpd") before linking?
> > 
> > Cheers,
> > 
> > Ben.
> > 
> > -- 
> > Ben Laurie                Phone: +44 (181) 994 6435  Email: ben@algroup.co.uk
> > Freelance Consultant and  Fax:   +44 (181) 994 6472
> > Technical Director        URL: http://www.algroup.co.uk/Apache-SSL
> > A.L. Digital Ltd,         Apache Group member (http://www.apache.org)
> > London, England.          Apache-SSL author
> > 

Re: Novel way to kill Apache

[Tony Sanders <sa...@bsdi.com>]

Ben Laurie wrote:
> > > If you build a program under Irix while it is running, it changes the code of
> > > the running program, usually resulting in a crash! This comes as a big surprise
Dean wrote:
> > It can happen on a lot of unixes in my experience.  In fact, all the ones
> > that let you scribble into a running executable (i.e. they don't lock the
> > executables).  That includes BSD*, linux, solaris, and IRIX.  But some of
> > them probably ship with ld that unlink the old executable and create a new
> > inode for the new one, (or gnu ld does this, I don't remember). 
> > 
> > Dynix/ptx won't let you rm a running executable, you have to rename it. 
> > That's the only oddball I've ever worked with though.

All BSD derived Uni that I have worked with (Sun OS, Convex OS,
BSD/OS) lock the on disk executable and refuse to allow you to
overwrite it.  Therefore, to install a new binary while it's running
you must remove the old one, leaving the old inode unlinked but
still around until either the process exists or the system crashes
and fsck cleans it up.

Re: Novel way to kill Apache

[Alexei Kosut <ak...@nueva.pvt.k12.ca.us>]

On Thu, 6 Feb 1997, Randy Terbush wrote:

> 
> HPUX is also known to do this.

Not my HP-UX: HP-UX 9.04, with gcc 2.7.2:

/bin/ld: Can't create httpd
/bin/ld: Text file busy
*** Error code 1

Stop.

-- 
________________________________________________________________________
Alexei Kosut <ak...@nueva.pvt.k12.ca.us>      The Apache HTTP Server
URL: http://www.nueva.pvt.k12.ca.us/~akosut/   http://www.apache.org/