Re: uml and -regparm=3

[Adrian Bunk <bunk@kernel.org>]

On Wed, Jan 09, 2008 at 10:20:49PM +0100, Miklos Szeredi wrote:
> > Miklos Szeredi <miklos@szeredi.hu> writes:
> > 
> > > FASTCALL is defined empty in -mm, but UML is not compiled with
> > > -mregparm=3 and so this breaks things (I noticed problems with
> > > rwsem_down_write_failed).
> > >
> > > Tried recompiling UML with -mregparm=3, but that resulted in a strange
> > > failure immediately after startup:
> > >
> > > |%G�%@: Invalid argument
> > >
> > > What's up?
> > 
> > UML links with glibc and that does not use -mregparm. 
> > 
> > You can only use -mregparm in user space if you recompile
> > all libraries too.
> 
> Ah, right.  I didn't think of that.
> 
> Does that mean that FASTCALL removals will have to be undone?  Or is
> there an alternative?

It's enough when we keep fastcall/FASTCALL in the few cases where UML 
calls assembler code with this calling convention. [1]

> Miklos

cu
Adrian

[1] http://lkml.org/lkml/2007/12/4/425

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