Re: [Announcement] "Exec Shield", new Linux security feature

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

Followup to:  <20030504222227.GB6808@twiddle.net>
By author:    Richard Henderson <rth@twiddle.net>
In newsgroup: linux.dev.kernel
>
> On Sun, May 04, 2003 at 10:25:26AM -0400, Chuck Ebbert wrote:
> > asmlinkage int sys_iopl(unsigned long unused)
> > {
> >         struct pt_regs * regs = (struct pt_regs *) &unused;       <== yuck!
> [...]
> >   Shouldnt it be like this?
> > 
> > asmlinkage int sys_iopl (struct pt_regs regs)
> 
> No, it should be like 
> 
>   int sys_iopl (struct pt_regs *regs)
> 
> and assembly language should push the proper address.
> 
> The struct-as-argument form allows the compiler to
> smash the entire structure as it sees fit.
> 

Hardly - it has to correspond to the ABI for the platform."

Presumably that's where the "asmlinkage" piece comes in.

	-hpa
-- 
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