Couldn't write debug register: No such process

Couldn't write debug register: No such process

[David L]

I'm getting this error when I try to continue after setting a remote target 
(gdbserver on a local socket).  I'm using gdb 6.3 that I compiled from 
source on a fedora core 3 system.

Couldn't write debug register: No such process


What does this mean?  Thanks...

            David

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Re: Couldn't write debug register: No such process

[Ramana Radhakrishnan]

On Tue, 2005-10-04 at 13:04 -0700, David L wrote:
> I'm getting this error when I try to continue after setting a remote target 
> (gdbserver on a local socket).  I'm using gdb 6.3 that I compiled from 
> source on a fedora core 3 system.
> 

Do you want to give the sequence of steps you followed to do this ? And
a small sample program. Someone could definitely help out. 

cheers
Ramana


> Couldn't write debug register: No such process
> 
> 
> What does this mean?  Thanks...
> 
>             David
> 
> _________________________________________________________________
> FREE pop-up blocking with the new MSN Toolbar  get it now! 
> http://toolbar.msn.click-url.com/go/onm00200415ave/direct/01/

Re: Couldn't write debug register: No such process

[Daniel Jacobowitz]

On Tue, Oct 04, 2005 at 01:04:58PM -0700, David L wrote:
> I'm getting this error when I try to continue after setting a remote target 
> (gdbserver on a local socket).  I'm using gdb 6.3 that I compiled from 
> source on a fedora core 3 system.
> 
> Couldn't write debug register: No such process
> 
> 
> What does this mean?  Thanks...

That something is broken.  There's not enough information in your
report to say more.  Is the gdbserver also running on an IA32 GNU/Linux
platform?  What's the transcript of the session look like?

-- 
Daniel Jacobowitz
CodeSourcery, LLC

Re: Couldn't write debug register: No such process

[David L]

[snip]
>On Tue, Oct 04, 2005 at 01:04:58PM -0700, David L wrote:
> > I'm getting this error when I try to continue after setting a remote 
>target
> > (gdbserver on a local socket).  I'm using gdb 6.3 that I compiled from
> > source on a fedora core 3 system.
> > Couldn't write debug register: No such process
> >
> >
> > What does this mean?  Thanks...
>
>That something is broken.  There's not enough information in your
>report to say more.  Is the gdbserver also running on an IA32 GNU/Linux
>platform?  What's the transcript of the session look like?


gdbserver is running on the same computer like this:
/usr/local/bin/gdbserver localhost:9005 testfixed testfixed.conf

From the gdb session:


GNU gdb 6.3
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 "i686-pc-linux-gnu"...Using host libthread_db 
library
"/lib/tls/libthread_db.so.1".

(gdb) target remote localhost:9005
Remote debugging using localhost:9005
0x00add7c0 in ?? ()
(gdb)  watch *((double *) 0x8155218)
Hardware watchpoint 1: *(double *) 135615000
(gdb) cont
Continuing.
Couldn't write debug register: No such process.

I'm not sure if it's ok to add a watchpoint like I did, but it works when I 
don't use gdbserver.  I did it like this because adding a watchpoint like 
this:

(gdb) watch confidence_[7]
Hardware watchpoint 6: this->confidence_[7]

doesn't work:

(gdb) cont
Continuing.
current stack frame does not contain a variable named `this'

So I found the address of confidence_[7]
(gdb) print &confidence_[7]
$3 = (double *) 0x8155218

and set the watchpoint on the address instead of on the variable name.

Cheers...

                             Dave

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Re: Couldn't write debug register: No such process

[Daniel Jacobowitz]

On Wed, Oct 05, 2005 at 12:02:32PM -0700, David L wrote:
> (gdb) target remote localhost:9005
> Remote debugging using localhost:9005
> 0x00add7c0 in ?? ()
> (gdb)  watch *((double *) 0x8155218)
> Hardware watchpoint 1: *(double *) 135615000
> (gdb) cont
> Continuing.
> Couldn't write debug register: No such process.
> 
> I'm not sure if it's ok to add a watchpoint like I did, but it works when I 
> don't use gdbserver.  I did it like this because adding a watchpoint like 
> this:

Gdbserver doesn't support watchpoints for x86, unfortunately.

-- 
Daniel Jacobowitz
CodeSourcery, LLC