Subject: Re: [PATCH] Complain about missing system calls.

From: Martin Schwidefsky <[email-masked]>
Date: Sat, 10 Mar 2007 10:58:13 +0100

On Fri, 2007-03-09 at 20:00 +0100, Andi Kleen wrote:
> > Not everybody has a simple indexed list of pointers :)  For example,
> > for vax-linux, we use a struct per syscall with the expected number of
> > on-stack longwords for the call.
> > 
> > So if something "new" is coming up, please keep in mind that it should
> > be flexible enough to represent that. :)
> 
> Are there plans to merge vax any time soon to mainline? 
> 
> Normally we don't care very much about out of tree code, especially
> if it adds complexity like this.
> 
> But I suspect s390 would need number of arguments anyways.

I can't quite follow that line of thought. Why does s390 need the number
of arguments? The wrapper of a compat system call implicitly knows how
many arguments a system calls to do the conversion. For a normal system
call we just call the function. Random example sys_read: the user space
loads the arguments to register %r2, %r3, %r4 and calls the system. The
register are not touched until sys_read is reached. Only sys_read cares
about the number of arguments in this case.

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