Messages in this thread | | | From | Andy Lutomirski <> | Date | Fri, 7 Feb 2014 08:40:45 -0800 | Subject | Re: [ARCH question] Do syscall_get_nr and syscall_get_arguments always work? |
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On Fri, Feb 7, 2014 at 4:58 AM, Jonas Bonn <jonas.bonn@gmail.com> wrote: > Hi Andy, > > On 5 February 2014 00:50, Andy Lutomirski <luto@amacapital.net> 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
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