Re: [GIT PULL] x86/paravirt for v2.6.33

["H. Peter Anvin" <hpa@zytor.com>]

On 12/09/2009 10:47 AM, Linus Torvalds wrote:
> 
> NOTE NOTE NOTE! Totally untested. Is the second argument even in %edx? I 
> don't remember, I didn't check, I'm just throwing this out as a "hey, 
> maybe something _like_ this can work" patch, and will be immediately 
> removing it from my machine after sending this email.
> 

The second argument is in %edx, but unlike 64 bits, it is not loaded
into that register a priory ("asmlinkage" means arguments are on the stack.)

As such, we need something looking like:

#define PTREGSCALL0(name)	\
ptregs_##name:			\
	leal	4(%esp),%eax;	\
	jmp sys_##name

#define PTREGSCALL1(name)	\
ptregs_##name:			\
	movl	4(%esp),%eax;	\
	leal	4(%esp),%edx;	\
	jmp sys_##name

#define PTREGSCALL2(name)	\
ptregs_##name:			\
	movl	4(%esp),%eax;	\
	movl	8(%esp),%edx;	\
	leal	4(%esp),%ecx;	\
	jmp sys_##name

If we need more than two arguments + pt_regs, then we have to set up a
temporary stack frame.

[Sorry, I'm sitting in a meeting so I can't actually write up a real patch]

	-hpa