[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date: Wed, 17 Jul 2013 15:39:35 +0200
From: Jens Gustedt <jens.gustedt@...ia.fr>
To: musl@...ts.openwall.com
Subject: Re: time code progress
Am Mittwoch, den 17.07.2013, 15:19 +0200 schrieb Szabolcs Nagy:
> note that the problem is not that __VA_ARGS__ is empty
> (it's not, contrary to what i might implied), but that
> if n becomes 0 (== __VA_ARGS__ expands to one argument),
> then there is no more arguments in the __SYSCALL_NARGS_X
> call to substitute for '...', so a simple fix would be
>
> #define __SYSCALL_NARGS(...) __SYSCALL_NARGS_X(__VA_ARGS__,7,6,5,4,3,2,1,0, tralala)
right, you always have the name of the syscall as first argument
> but i'm not sure if this should be fixed (this is internal
> code and i think there are no 0 argument syscalls)
>
> i just wanted to record how i found the close without fd issue
> (which shows that some kind of type checking for syscall
> arguments would help libc hacking.. but that's non-trivial
> to do)
if there are really no 0 argument syscalls
#define __SYSCALL_NARGS(...) __SYSCALL_NARGS_X(__VA_ARGS__,7,6,5,4,3,2,1, tralali, tralala)
would be an implementation of a first consistency test. But wait my
man page of syscall(2) already has an example of a 0 argument one.
Other consistency checks would probably a bit more difficult to
implement. I could imagine how to check for the number of arguments of
particular syscalls. Type checking would be more difficult, and would
probably need some maintenance.
Jens
--
:: INRIA Nancy Grand Est :: http://www.loria.fr/~gustedt/ ::
:: AlGorille ::::::::::::::: office Nancy : +33 383593090 ::
:: ICube :::::::::::::: office Strasbourg : +33 368854536 ::
:: ::::::::::::::::::::::::::: gsm France : +33 651400183 ::
:: :::::::::::::::::::: gsm international : +49 15737185122 ::
Download attachment "signature.asc" of type "application/pgp-signature" (199 bytes)
Powered by blists - more mailing lists
Confused about mailing lists and their use?
Read about mailing lists on Wikipedia
and check out these
guidelines on proper formatting of your messages.
