Re: [PATCH] x86/syscall: Avoid memcpy() for ia32 syscall_get_arguments()

[Kees Cook <kees@kernel.org>]

On Thu, Jul 11, 2024 at 02:01:53PM -0700, Dave Hansen wrote:
> On 7/8/24 13:22, Kees Cook wrote:
> ...
> > diff --git a/arch/x86/include/asm/syscall.h b/arch/x86/include/asm/syscall.h
> > index 2fc7bc3863ff..7c488ff0c764 100644
> > --- a/arch/x86/include/asm/syscall.h
> > +++ b/arch/x86/include/asm/syscall.h
> > @@ -82,7 +82,12 @@ static inline void syscall_get_arguments(struct task_struct *task,
> >  					 struct pt_regs *regs,
> >  					 unsigned long *args)
> >  {
> > -	memcpy(args, &regs->bx, 6 * sizeof(args[0]));
> > +	args[0] = regs->bx;
> > +	args[1] = regs->cx;
> > +	args[2] = regs->dx;
> > +	args[3] = regs->si;
> > +	args[4] = regs->di;
> > +	args[5] = regs->bp;
> >  }
> >  
> 
> Yeah, that's much less magic.  I'll stick this in the queue to go in to
> the tree in a few weeks.
> 
> Acked-by: Dave Hansen <dave.hansen@linux.intel.com>

Ping. I can take it via the hardening tree if you want, though?

-- 
Kees Cook