From: Eric Covener <covener@apache.org>
Date: Mon, 30 Mar 2009 13:26:02 +0000 (+0000)
Subject: Clarify when CoreDumpDirectory can be moot based on OS configuration, and
X-Git-Tag: 2.3.3~747
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=9589a9954efc2a1f0f53d0d98e70ab0af4b38272;p=thirdparty%2Fapache%2Fhttpd.git

Clarify when CoreDumpDirectory can be moot based on OS configuration, and
mention SIGQUIT/3 not being processed by the signal handler.

SIGQUIT may unfortunately be a go-to signal for java users.



git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@759957 13f79535-47bb-0310-9956-ffa450edef68
---

diff --git a/docs/manual/mod/mpm_common.xml b/docs/manual/mod/mpm_common.xml
index 8fe038c7e8c..c717dd274b2 100644
--- a/docs/manual/mod/mpm_common.xml
+++ b/docs/manual/mod/mpm_common.xml
@@ -129,13 +129,17 @@ switch before dumping core</description>
 
 <usage>
     <p>This controls the directory to which Apache attempts to
-    switch before dumping core. The default is in the
-    <directive module="core">ServerRoot</directive> directory, however
-    since this should not be writable by the user the server runs
-    as, core dumps won't normally get written. If you want a core
-    dump for debugging, you can use this directive to place it in a
-    different location.</p>
-
+    switch before dumping core. If your operating system is configured to
+    create core files in the crashing processes working directory, 
+    <directive>CoreDumpDirectory</directive> is necessary to change working
+    directory from the default <directive module="core">ServerRoot</directive> 
+    directory, which should not be writable by the user the server runs as.</p>
+
+    <p>If you want a core dump for debugging, you can use this directive to 
+    place it in a different location. This directive has no effect if your
+    operating system is not configured to write core files to the crashing 
+    processes working directory.</p>
+    
     <note><title>Core Dumps on Linux</title>
       <p>If Apache starts as root and switches to another user, the
       Linux kernel <em>disables</em> core dumps even if the directory is
@@ -143,6 +147,17 @@ switch before dumping core</description>
       on Linux 2.4 and beyond, but only if you explicitly configure a <directive
       >CoreDumpDirectory</directive>.</p>
     </note>
+
+    <note><title>Specific signals</title>
+      <p><directive>CoreDumpDirectory</directive> processing only occurs for 
+      a select set of fatal signals: SIGFPE, SIGILL, SIGABORT, 
+      SIGSEGV, and SIGBUS.</p>
+      <p>On some operating systems, SIGQUIT also results in a core dump but
+      does not go through <directive>CoreDumpDirectory</directive> or
+      <directive>EnableExceptionHook</directive> processing, so the core
+      location is dictated entirely by the operating system.</p>
+    </note>
+
 </usage>
 </directivesynopsis>