On Wed, Mar 23, 2005 at 05:48:10PM +1100, Stephen Rothwell wrote:
> This patch creates sys_shmat and sys_smhatcall and uses them wherever
> possible - this tidies up sys_ipc a bit in most cases. I have not touched um
> arch.
The concept is great, but I'd quibble over the details ...
> I am eventually aiming at consolidating (as much as possible of) sys_ipc
> and doing compat_sys_ipc.
Great, but please remember not all architectures have a sys_ipc (looks like
alpha, ia64, parisc and x86_64 according to a fairly recent version of glibc).
> +++ linus-compat_sys_ipc.2/arch/parisc/kernel/sys_parisc.c 2005-03-23
> 16:41:53.000000000 +1100
> @@ -163,13 +163,7 @@
>
> long sys_shmat_wrapper(int shmid, char __user *shmaddr, int shmflag)
> {
> - unsigned long raddr;
> - int r;
> -
> - r = do_shmat(shmid, shmaddr, shmflag, &raddr);
> - if (r < 0)
> - return r;
> - return raddr;
> + return sys_shmatcall(shmid, shmaddr, shmflag);
> }
I don't see the need for a wrapper function in sys_parisc.c -- would
make sense to just call the sys_shmatcall() directly. I suspect the same
goes for Alpha's osf_shmat() function.
> diff -ruN linus-compat_sys_ipc.1/ipc/shm.c linus-compat_sys_ipc.2/ipc/shm.c
> --- linus-compat_sys_ipc.1/ipc/shm.c 2005-03-18 04:08:16.000000000 +1100
> +++ linus-compat_sys_ipc.2/ipc/shm.c 2005-03-23 17:18:28.000000000 +1100
> +asmlinkage long sys_shmat(int shmid, char __user *shmaddr, int shmflg,
> + unsigned long __user *addr)
> +asmlinkage long sys_shmatcall(int shmid, char __user *shmaddr, int shmflg)
> +{
> + ulong raddr;
> + long ret;
> +
> + ret = do_shmat(shmid, shmaddr, shmflg, &raddr);
> + return ret ? ret : raddr;
> +}
I dislike the naming here. The manpage for shmat is the three-argument
version. The only reason we have the four-argument version is because
of the silly sys_ipc multiplexer. So I think sys_shmat() should be
the three-argument form and we should rename the existing sys_shmat()
to something like ipc_shmat(). Does it need to be asmlinkage?
--
"Next the statesmen will invent cheap lies, putting the blame upon
the nation that is attacked, and every man will be glad of those
conscience-soothing falsities, and will diligently study them, and refuse
to examine any refutations of them; and thus he will by and by convince
himself that the war is just, and will thank God for the better sleep
he enjoys after this process of grotesque self-deception." -- Mark Twain
