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:
> > I don't understand why gethostbyname() would call puts() - and why
> > that would then crash!
>
> I can't explain why it's calling puts() directly either.  Bad RAM
> could cause something bizarre like this, or a corrupt/broken binary.

Yeah.. I have rebuilt lots of stuff, although not libc.

This machine has build world, kernel, KDE, etc.. I am pretty sure the hardware is OK as none of the builds had an issue.

> The libc code I'm looking at (src/lib/libc/net/gethostnameadr.c and
> gethostbydns.c) don't call puts) don't appear to call puts()
> directly. Of course, there may be macros used which do this.

I had a look - there certainly isn't anywhere obvious it's hapening. I guess the only thing now is to rebuild with debugging.

> There are some places in the resolver code where printing to stdout
> or stderr can occur.  I'd expect to see a longer stack trace (meaning
> more functions between gethostbyname() and puts()) if that were the
> case, though.
>
> There's a decent document on how to debug httpd below.  You'll need
> to start httpd with -X or with "MaxClients 1", to keep it from
> forking. You can do that through gdb if you want, or (what I prefer,
> since I'm not very good with gdb) use truss.

OK thanks.

> http://httpd.apache.org/dev/debugging.html
>
> If you go the truss route, be sure to use -a -s 4096.  You'd be able
> to see what actual string is being output via puts(), assuming it
> gets as far as to start writing data to the fd.

Hmm I had a go with gdb but it doesn't work properly.. I got this..
[midget 16:33] /tmp/work/usr/ports/www/apache13-modssl/work/apache_1.3.41 >sudo gdb src/httpd
Password:
GNU gdb 6.1.1 [FreeBSD]
Copyright 2004 Free Software Foundation, Inc.
GDB is free software, covered by the GNU General Public License, and you are
welcome to change it and/or distribute copies of it under certain conditions.
Type "show copying" to see the conditions.
There is absolutely no warranty for GDB.  Type "show warranty" for details.
This GDB was configured as "i386-marcel-freebsd"...
(gdb) run -X
Starting program: /data/tmp/work/usr/ports/www/apache13-modssl/work/apache_1.3.41/src/httpd -X
[New LWP 100212]
[New Thread 0x819d300 (LWP 100212)]
[New LWP 100212]
suspend error: generic error
[Switching to LWP 100212]
Stopped due to shared library event
(gdb) info thread
Cannot find new threads: generic error
(gdb) bt
#0  0x2807fda0 in r_debug_state () from /libexec/ld-elf.so.1
#1  0x2808367d in dlclose () from /libexec/ld-elf.so.1
#2  0x28706164 in zend_hash_apply_deleter ()
   from /usr/local/libexec/apache/libphp5.so
#3  0x287063a8 in zend_hash_graceful_reverse_destroy ()
   from /usr/local/libexec/apache/libphp5.so
#4  0x286fc89e in zend_shutdown () from /usr/local/libexec/apache/libphp5.so
#5  0x286bb5bf in php_module_shutdown () from /usr/local/libexec/apache/libphp5.so
#6  0x286bb66b in php_module_shutdown_wrapper ()
   from /usr/local/libexec/apache/libphp5.so
#7  0x28776aaa in apache_php_module_shutdown_wrapper ()
   from /usr/local/libexec/apache/libphp5.so
#8  0x080524d9 in ap_clear_pool (a=0x8106010) at alloc.c:1937
#9  0x0805f0f6 in standalone_main (argc=Variable "argc" is not available.
) at http_main.c:5480
#10 0x08060c1f in main (argc=-716130182, argv=0x1) at http_main.c:5883

I tried truss and it seemed to be taking a long time (5-10 minutes) and
generating a lot of seemingly identical logging :(

-- 
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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