Re: syscall documentation (2)

[Stephen Rothwell <sfr@canb.auug.org.au>]

On Thu, 6 Feb 2003 21:08:10 +0100 (MET) Andries.Brouwer@cwi.nl wrote:
>
> The next new page is futex.2.
> 
> Comments welcome.
> Andries
> aeb@cwi.nl
> 
> -------------------------------
> NAME
>        futex - Fast Userspace Locking system call
> 
> SYNOPSIS
>        #include <linux/futex.h>
> 
>        #include <sys/time.h>
> 
>        int  sys_futex (void *futex, int op, int val, const struct
>        timespec *timeout);

In discussions with Rusty, we decided that the first parameter
to sys_futex should be a u32 * i.e. a pointer to a 32 bit quantity
in user space.  This is what is assumed by the code at the moment.
The kernel doesn't really care if it is signed or not as the only
test done on it is for equality.

I will be submitting a patch to that effect shortly.  This also makes
it much easier to do the compatibility layer interface ...

>        The futex argument needs to point to  an  aligned  integer
                                                            ^^^^^^^
32 bit quantity

-- 
Cheers,
Stephen Rothwell                    sfr@canb.auug.org.au
http://www.canb.auug.org.au/~sfr/