I'm trying to debug a rather difficult data-overwriting problem, and it
would be a big help to be able to use a data breakpoint.
Is there any easy way of doing this? I'd prefer not to use a kernel
debugger, because the address of the breakpoint and the time when it's
needed are determined dynamically.
Does anybody have a little lightweight procedure for setting one of the
x86's debug registers to point to a particular location in kernel memory
space? I don't care if the whole system crashes when the debug exception
occurs, just so long as I can get a stack trace and find out where the
overwrite comes from.
Alan Stern
On Tue, Nov 01, 2005 at 04:30:26PM -0500, Alan Stern wrote:
> I'm trying to debug a rather difficult data-overwriting problem, and it
> would be a big help to be able to use a data breakpoint.
>
> Is there any easy way of doing this? I'd prefer not to use a kernel
> debugger, because the address of the breakpoint and the time when it's
> needed are determined dynamically.
>
> Does anybody have a little lightweight procedure for setting one of the
> x86's debug registers to point to a particular location in kernel memory
> space? I don't care if the whole system crashes when the debug exception
> occurs, just so long as I can get a stack trace and find out where the
> overwrite comes from.
>
>
Hi Alan
Probably watchpoint probes could be useful for this..
http://www.ussg.iu.edu/hypermail/linux/kernel/0508.3/1407.html
http://sourceware.org/ml/systemtap/2005-q3/msg00097.html
Thanks
Maneesh
--
Maneesh Soni
Linux Technology Center,
IBM India Software Labs,
Bangalore, India
email: [email protected]
Phone: 91-80-25044990
On Wed, 2 Nov 2005, Maneesh Soni wrote:
> On Tue, Nov 01, 2005 at 04:30:26PM -0500, Alan Stern wrote:
> > I'm trying to debug a rather difficult data-overwriting problem, and it
> > would be a big help to be able to use a data breakpoint.
> >
> > Is there any easy way of doing this? I'd prefer not to use a kernel
> > debugger, because the address of the breakpoint and the time when it's
> > needed are determined dynamically.
> >
> > Does anybody have a little lightweight procedure for setting one of the
> > x86's debug registers to point to a particular location in kernel memory
> > space? I don't care if the whole system crashes when the debug exception
> > occurs, just so long as I can get a stack trace and find out where the
> > overwrite comes from.
> >
> >
>
> Hi Alan
>
> Probably watchpoint probes could be useful for this..
>
> http://www.ussg.iu.edu/hypermail/linux/kernel/0508.3/1407.html
>
> http://sourceware.org/ml/systemtap/2005-q3/msg00097.html
Hi Maneesh:
That's exactly what I was looking for. Thanks!
Alan Stern