Path: utzoo!attcan!uunet!cs.utexas.edu!sun-barr!newstop!sun!snafu!lm
From: lm@snafu.Sun.COM (Larry McVoy)
Newsgroups: comp.unix.wizards
Subject: Re: Indirect system call (WARNING)
Keywords: doesn't aways work
Message-ID: <128380@sun.Eng.Sun.COM>
Date: 25 Nov 89 18:48:06 GMT
References: <28945@shemp.CS.UCLA.EDU> <8494@cbmvax.UUCP> <1598@crdos1.crd.ge.COM> <105@amix.commodore.com>
Sender: news@sun.Eng.Sun.COM
Reply-To: lm@sun.UUCP (Larry McVoy)
Organization: Sun Microsystems, Mountain View
Lines: 20

There has been some discussion of the use of syscall() on this group.  Just a
fair warning to budding hackers - if my memory servers me correctly there are
times when it won't work.  In particular, syscall returns an int and if you
are calling a syscall that sends out stuff in more than one register (see
below) it won't work.  No, I don't have a list of stuff that fails, but you
should be able to look at the man pages and figure it out.  

--larry

[From Sun's syscall man page:
BUGS
     There is no way to simulate system calls such  as  pipe(2V),
     which  return  values in register d1 on Sun-3 and Sun-4 sys-
     tems or in register %edx on Sun386i systems.
]


	 What I say is my opinion.  I am not paid to speak for Sun.

Larry McVoy, Sun Microsystems                          ...!sun!lm or lm@sun.com