apachectl gracefult causes Signal 11 crash after 6.3 to 7.0 upgrade [SOLVED]

[Daniel O'Connor]

On Thu, 12 Jun 2008, Jeremy Chadwick wrote:
> > Yeah.. I have rebuilt lots of stuff, although not libc.
>
> Huh?

Sorry, I meant that I have to explicitly rebuilt it since I did a 
buildworld to make sure it wasn't fubar'd somehow.

I haven't done that mainly because I find it extremely unlikely it would 
only break Apache in this manner but nothing else.

I might rebuild it to get debug symbols though..

> > This machine has build world, kernel, KDE, etc.. I am pretty sure
> > the hardware is OK as none of the builds had an issue.
>
> libc is part of world.  *Every* program relies (is linked with) on
> libc.

Yes, sorry for my confusing turn of phrase! :)

> > #10 0x08060c1f in main (argc=-716130182, argv=0x1) at
> > http_main.c:5883
>
> I can't say much about this, but I'm willing to bet it's the result
> of some Apache + PHP weirdness.  I've never known gdb on FreeBSD to
> be as reliable/useful as, say, on Linux or Solaris.  Always
> odd/strange things happening with gdb on FreeBSD.

Yeah :(
> > I tried truss and it seemed to be taking a long time (5-10 minutes)
> > and generating a lot of seemingly identical logging :(
>
> Okay, let's backtrack here.
>
> The OP states that he can induce a segfault of httpd when doing
> "apachectl graceful".  Is that the exact problem you're seeing, or
> are you seeing problems where PHP/Apache segfaults during operation? 
> I just want to be clear.
>
> If the latter, then truss "generating lots of seemingly identical
> logging" is probably expected.  I'm guessing it's select() or poll()
> or something related to kqueue/kevent, as it'd be waiting for I/O on
> the HTTP socket.  You'd have to submit the HTTP request to the PHP
> script to get it to crash.
>
> In either case, you may have to resort to using ktrace + kdump, which
> may or may not help narrow this down.
>
> Use "ktrace -i -t+ httpd -X" (I hope that'll work; I'm not sure if
> ktrace allows you to pass arguments to a command), which will start
> populating a file called ktrace.out.  You should then do the
> "apachectl graceful" in another window (or if the latter, submit the
> HTTP request), and ktrace may exit when the segfault happens (I'm not
> sure about this; it may sit there indefinitely).
>
> In the case it doesn't exit, and you've confirmed the core happened
> (check "dmesg"), you should ^C the ktrace and then do "ktrace -C"
> just to be sure nothing got wedged.
>
> You'll then have to use kdump to decode the contents of ktrace.out.



-- 
Daniel O'Connor software and network engineer
for Genesis Software - http://www.gsoft.com.au
"The nice thing about standards is that there
are so many of them to choose from."
  -- Andrew Tanenbaum
GPG Fingerprint - 5596 B766 97C0 0E94 4347 295E E593 DC20 7B3F CE8C
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