gdb/2171: No backtrace generated on amd64

[Daniel Jacobowitz]

The following reply was made to PR gdb/2171; it has been noted by GNATS.

From: Daniel Jacobowitz <drow@false.org>
To: Joe Hansche <madcoder@gmail.com>
Cc: gdb-gnats@sources.redhat.com
Subject: Re: gdb/2171: No backtrace generated on amd64
Date: Sat, 16 Sep 2006 16:26:53 -0400

 On Sat, Sep 16, 2006 at 01:15:28AM -0600, Joe Hansche wrote:
 > >This is a shared library address.  Does info shared work?  It looks
 > >like your system libraries are undebuggable, not the binary itself.
 > 
 > (gdb) info shared
 > No shared libraries loaded at this time.
 
 Is PHP dynamically linked?  If it is, I can only assume that either
 your kernel produces broken core dumps - this happens from time to time
 - or that something is very badly wrong with your GDB.
 
 Take a look with readelf -l at the php binary and the core file.
 The binary should have a DYNAMIC entry.  Do any of the LOAD entries for
 the core file cover that same address region?  If so, do they have
 non-zero values in FileSiz?
 
 My suspicion is that you have one of the broken kernel versions, which
 fails to dump sections if they are modified and then mprotect'd to
 readonly.
 
 -- 
 Daniel Jacobowitz
 CodeSourcery