On Fri, 2014-02-07 at 08:40 -0800, Andy Lutomirski wrote: > On Fri, Feb 7, 2014 at 4:58 AM, Jonas Bonn <jonas.bonn@xxxxxxxxx> wrote: > > Hi Andy, > > > > On 5 February 2014 00:50, Andy Lutomirski <luto@xxxxxxxxxxxxxx> 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... Al just indicated to me that on at least ia64, syscall_get_arguments() is really expensive. So maybe not a deal breaker, but sounds like we'd lose a lot of performance trying to get them at syscall exit... -- To unsubscribe from this list: send the line "unsubscribe linux-arch" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
