[parisc-linux] utssys?

[parisc-linux] utssys?

[Matthew Wilcox]

Can anyone tell me what the utssys() system call does?  There's no manual
page for it.  From tusc, I can see:

utssys("HP-UX", 0, 0) ............................................ = 0

so all I need do to get it to work on Linux is return 0, but I'd like
to understand a little more.

I also can't find a manual page for sigsetreturn() which I probably need
to understand more deeply than utssys :-)

-- 
Matthew Wilcox <willy@bofh.ai>
"Windows and MacOS are products, contrived by engineers in the service of
specific companies. Unix, by contrast, is not so much a product as it is a
painstakingly compiled oral history of the hacker subculture." - N Stephenson

Re: [parisc-linux] utssys?

[John David Anglin]

> 
> 
> Can anyone tell me what the utssys() system call does?  There's no manual
> page for it.  From tusc, I can see:
> 
> utssys("HP-UX", 0, 0) ............................................ = 0

Just guessing but it might be for uname and setuname.

Dave
-- 
J. David Anglin                                  dave.anglin@nrc.ca
National Research Council of Canada              (613) 990-0752 (FAX: 952-6605)

Re: [parisc-linux] utssys?

[Stan Sieler]

Re:

> Can anyone tell me what the utssys() system call does?  There's no manual
> page for it.  From tusc, I can see:
> 
> utssys("HP-UX", 0, 0) ............................................ = 0

Re: [parisc-linux] utssys?

[John David Anglin]

> 
> Re:
> 
> > Can anyone tell me what the utssys() system call does?  There's no manual
> > page for it.  From tusc, I can see:
> > 
> > utssys("HP-UX", 0, 0) ............................................ = 0
> 
> >From decompiling, it doesn't appear to do much.  The kernel utssys
> routine (called to handle system call (SYS_utssys, #57)), is short,
> with one external call ... to a short routine that has no procedure calls
> at all.  That's where I stopped looking.

Re: [parisc-linux] utssys?

[Kevin Vajk]

On Sat, 7 Aug 1999, Matthew Wilcox wrote:

> Can anyone tell me what the utssys() system call does?  There's no manual
> page for it.

It takes 3 arguments; a pointer, and two ints.

The second int is the request type.  If an unknown request type is
passed in, it returns EFAULT.
If the request does something like sets the hostname, the first int
passed in is the number of bytes in the hostname.
If the request does something like gets the hostname, the first int
passed in is the size of the character buffer for it to put the answer in.
Otherwise it's ignored.

type=0 gets the utsname (see sys/utsname.h).  first int is ignored.
type=1 is obsolete; it returns EFAULT
I don't know what type=2 does.
type=3 sets utsname.nodename, if you're root
type=4 sets the hostname, if you're root
type=5 gets the hostname
type=6 sets utsname.sysname, if you're root
type=7 is undocumented; it's only used during OS updates.  Just return EFAULT.


Here's an example of using utssys() to get the system's hostname:

#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <syscall.h>
int main(argc,argv)
int argc; char *argv[];
{
    char buf[2048];
    memset(buf, 0, sizeof(buf));
    /*  utssys(buf, sizeof(buf), 5);  */
    if( syscall( SYS_UTSSYS, buf, sizeof(buf)-1, 5 ) == -1 ) {
        perror("utssys");
        exit(1);
    }
    printf("Hostname = \"%s\"\n", buf);
    exit(0);
}

- Kevin Vajk
  <kvajk@cup.hp.com>

Re: [parisc-linux] utssys?

[Kevin Vajk]

On Tue, 10 Aug 1999, Kevin Vajk wrote:

> I don't know what type=2 does.

Whoops!  Yes, I do...

It implements ustat().  First argument is the dev, like this:
ustat(dev, buf) ==> utssys(buf, dev, 2)

- Kevin Vajk
  <kvajk@cup.hp.com>

Re: [parisc-linux] utssys?

[Gyula Matics]

> Can anyone tell me what the utssys() system call does? There's no manual 
> page for it. From tusc, I can see: 
> 
> utssys("HP-UX", 0, 0) ............................................ = 0 
> 
> so all I need do to get it to work on Linux is return 0, but I'd like 
> to understand a little more. 

On Solaris it's 3 syscalls, and you have some documentation in sys/syscall.h
and sys/utssys.h. One of them is used by fuser.
Maybe you can find some info in the hpux headers?
(Can't check, no access for hpux right now)

int utssys(char *path, int flags, int type, char *obuf)

#define SYS_utssys      57
        /*
         *subcodes (third argument):
         *      uname(obuf)  (obsolete)   :: syscall(57, obuf, ign, 0)
         *                                      subcode 1 unused
         *      ustat(dev, obuf)          :: syscall(57, obuf, dev, 2)
         *      fusers(path, flags, obuf) :: syscall(57, path, flags, 3, obuf)
         *      see <sys/utssys.h>
         */

Gyula