Re: [Fastboot] Re: [-mm patch] i386: enable REGPARM by default

[Daniel Jacobowitz <dan@debian.org>]

On Mon, Jun 27, 2005 at 06:59:41PM +0530, Vivek Goyal wrote:
> On Fri, Jun 24, 2005 at 01:28:26PM -0700, Andrew Morton wrote:
> > Adrian Bunk <bunk@stusta.de> wrote:
> > >
> > > This patch:
> > > - removes the dependency of REGPARM on EXPERIMENTAL
> > > - let REGPARM default to y
> > 
> > hm, a compromise.
> > 
> > One other concern I have with this is that I expect -mregparm will make
> > kgdb (and now crashdump) less useful.  When incoming args are on the stack
> > you have a good chance of being able to see what their value is by walking
> > the stack slots.
> > 
> > When the incoming args are in registers I'd expect that it would be a lot
> > harder (or impossible) to work out their value.
> > 
> > Have the kdump guys thought about (or encountered) this?

GDB is more than capable of handling this - if your compiler is saving
arguments to the stack and dumping out useful information for the
debugger about where it put them.  Recent GCC versions are generally
pretty good about either saving the argument or clearly telling GDB
that it was not saved.


-- 
Daniel Jacobowitz
CodeSourcery, LLC