Re: [ARCH question] Do syscall_get_nr and syscall_get_arguments always work?

On Fri, Feb 7, 2014 at 4:58 AM, Jonas Bonn <jonas.bonn(a)gmail.com&gt; wrote: > Hi Andy, > > On 5 February 2014 00:50, Andy Lutomirski <luto(a)amacapital.net&gt; wrote: >> >> I can't even find the system call entry point on mips. >> >> >> Is there a semi-official answer here? > > I don't have an official answer for you, but when I wanted to do > something with these entry points a couple of years back I discovered > that they aren't very thoroughly implemented across the various > architectures. I started cleaning this up and can probably dig up > some of this for you if you need it. The syscall_get_xyz functions are certainly implemented and functional in all relevant architectures -- the audit code is already using them. The thing I'm uncertain about is whether they are usable with no syscall slow path bits set.

I guess that, if the syscall restart logic needs to read the argument registers, then they're probably reliably saved... --Andy