Re: tdep/1586: GDB doesn't support remote debug of ARM pic code

[Daniel Jacobowitz <drow at false dot org>]

The following reply was made to PR tdep/1586; it has been noted by GNATS.

From: Daniel Jacobowitz <drow@false.org>
To: rschmitt@bluepeach.com
Cc: gdb-gnats@sources.redhat.com, mribeiro@hypercom.com
Subject: Re: tdep/1586: GDB doesn't support remote debug of ARM pic code
Date: Wed, 17 Mar 2004 15:13:08 -0500

 On Sun, Mar 14, 2004 at 09:39:47PM -0000, rschmitt@bluepeach.com wrote:
 > 
 > >Number:         1586
 > >Category:       tdep
 > >Synopsis:       GDB doesn't support remote debug of ARM pic code
 > >Confidential:   no
 > >Severity:       serious
 > >Priority:       medium
 > >Responsible:    unassigned
 > >State:          open
 > >Class:          sw-bug
 > >Submitter-Id:   net
 > >Arrival-Date:   Sun Mar 14 21:48:00 UTC 2004
 > >Closed-Date:
 > >Last-Modified:
 > >Originator:     rschmitt@bluepeach.com
 > >Release:        GDB 6.1
 > >Organization:
 > >Environment:
 > I use cygwin with a GDB built for xscale-elf.  I also use connect to a remote target
 > >Description:
 > When stepping into an ARM subroutine in position independent code
 > (-fpic), gdb will get confused and set the routine's entry breakpoint
 > at the wrong place.
 > 
 > As I see it, there are two problems.  First, when using remote debug,
 > gdb will not relocate the .plt section in the symbol table.  I've
 > added code to relocate the .plt section with the same offset that is
 > used for the .text section (see attached dif).  The second issue is
 > that arm-tdep does not recognize the .plt trampolines.  I've added
 > code to recognize the trampoline and correctly calculate the true
 > offset. (see attachment)
 
 What sort of target are you really using?  xscale-elf is a barebones
 embedded target; it does not support shared libraries and it does not
 support PLT stubs.  Their format depends on the operating system you
 are targetting.
 
 -- 
 Daniel Jacobowitz
 MontaVista Software                         Debian GNU/Linux Developer