Re: [PATCH -mm 1/9] unshare system call: system call handler function

[ebiederm@xmission.com (Eric W. Biederman)]

JANAK DESAI <janak@us.ibm.com> writes:

> [PATCH -mm 1/9] unshare system call: system call handler function 
>
> sys_unshare system call handler function accepts the same flags as
> clone system call, checks constraints on each of the flags and invokes
> corresponding unshare functions to disassociate respective process
> context if it was being shared with another task. 
>
> Changes since the first submission of this patch on 12/12/05:
> 	- Moved cleaning up of old shared structures outside of the
> 	  block that holds task_lock (12/13/05)
>  
> Signed-off-by: Janak Desai <janak@us.ibm.com>
>  
> ---
>  
>  fork.c | 232 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
>  1 files changed, 232 insertions(+)
>  
> diff -Naurp 2.6.15-rc5-mm2/kernel/fork.c 2.6.15-rc5-mm2+patch/kernel/fork.c
> --- 2.6.15-rc5-mm2/kernel/fork.c	2005-12-12 03:05:59.000000000 +0000
> +++ 2.6.15-rc5-mm2+patch/kernel/fork.c	2005-12-13 18:38:26.000000000 +0000
> @@ -1330,3 +1330,235 @@ void __init proc_caches_init(void)
>  			sizeof(struct mm_struct), 0,
>  			SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL, NULL);
>  }
> +
> +
> +/*
> + * Check constraints on flags passed to the unshare system call and
> + * force unsharing of additional process context as appropriate.
> + */

If it isn't legal how about we deny the unshare call.
Then we can share this code with clone.

Eric