From nobody@hyperreal.com  Wed Jan  8 12:47:58 1997
Received: by taz.hyperreal.com (8.8.3/V2.0) id MAA03466; Wed, 8 Jan 1997 12:47:58 -0800 (PST)
Message-Id: <199701082047.MAA03466@taz.hyperreal.com>
Date: Wed, 8 Jan 1997 12:47:58 -0800 (PST)
From: Adrian Filipi-Martin <adrian@virginia.edu>
Reply-To: adrian@virginia.edu
To: apbugs@hyperreal.com
Subject: starting/restarting httpd causes sigaction errors to be logged
X-Send-Pr-Version: 3.2

>Number:         98
>Category:       os-hpux
>Synopsis:       starting/restarting httpd causes sigaction errors to be logged
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    apache
>State:          closed
>Class:          sw-bug
>Submitter-Id:   apache
>Arrival-Date:   Wed Jan  8 12:50:01 1997
>Last-Modified:  Fri Jan 24 18:08:26 PST 1997
>Originator:     adrian@virginia.edu
>Organization:
>Release:        1.2b4
>Environment:
HP-UX 10.10
gcc version 2.7.2.1
Other than tweaking Configuration/Configuration.tmpl, no modifications were made
to the sources.
>Description:
When starting httpd or restarting it with a SIGHUP, the following is logged 
to the error_log:

[Wed Jan  8 14:21:03 1997] created shared memory segment #4206
[Wed Jan  8 14:21:03 1997] sigaction(SIGSEGV): Invalid argument
[Wed Jan  8 14:21:03 1997] sigaction(SIGBUS): Invalid argument
[Wed Jan  8 14:21:03 1997] Server configured -- resuming normal operations

(Note that the shared memory segment message is only present when the daemon
is send a SIGHUP signal to restart it.)

These error messages do not appear to have any real effect upon the operation
of the server.  I expect they would not matter until it has either a bus or 
a segment fault.

In any case, I looked at the source with gdb and the fact that a sigaction 
structure is not initialized completely in http_main.c seems to be the culprit.
In any case a small patch is included below that does the required clearing of
the sigaction structure and fixes the problem.
>How-To-Repeat:
Either start the server or restart it with a SIGHUP.  Then hope that you 
do not get lucky and have the aforementioned sigaction structure placed in a 
block of zeroed out memory.
>Fix:
I suspect that invalid arguments are being passed to the sigaction() functions.

Here is a patch to fix this:
: adrian@huron; diff -c -C 5 http_main.c~ http_main.c
*** http_main.c~        Mon Dec 30 21:29:00 1996
--- http_main.c Wed Jan  8 15:45:52 1997
***************
*** 1271,1280 ****
--- 1271,1281 ----
  
  void set_signals()
  {
  #ifndef NO_USE_SIGACTION
      struct sigaction sa;
+     memset(&sa,0,sizeof sa);
  
      if (!one_process) {
        sa.sa_handler = (void (*)())seg_fault;
        if (sigaction(SIGSEGV, &sa, NULL) < 0)
            log_unixerr("sigaction(SIGSEGV)", NULL, NULL, server_conf);
%0
>Audit-Trail:
State-Changed-From-To: open-closed
State-Changed-By: marc
State-Changed-When: Fri Jan 24 18:08:26 PST 1997
State-Changed-Why:
Fix applied in version 1.110 of http_main.c, which will
be available in 1.2b5 when released.

>Unformatted: