Re: [PATCH] unshare: Error if passed unsupported flags

[Janak Desai <janak@us.ibm.com>]

Thanks Eric. I had just started to do this based on Andrew's request.

-Janak

Eric W. Biederman wrote:

>This patch does a bare bones trivial patch to ensure we always
>get -EINVAL on the unsupported cases for sys_unshare.  If this
>goes in before 2.6.16 it allows us to forward compatible with
>future applications using sys_unshare.
>
>Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
>
>
>---
>
> kernel/fork.c |    6 ++++++
> 1 files changed, 6 insertions(+), 0 deletions(-)
>
>46868b4b6ebeb9042dded68a6f6301ffe06820c9
>diff --git a/kernel/fork.c b/kernel/fork.c
>index 46060cb..411b10d 100644
>--- a/kernel/fork.c
>+++ b/kernel/fork.c
>@@ -1535,6 +1535,12 @@ asmlinkage long sys_unshare(unsigned lon
> 	struct sem_undo_list *new_ulist = NULL;
> 
> 	check_unshare_flags(&unshare_flags);
>+       
>+	/* Return -EINVAL for all unsupported flags */
>+	err = -EINVAL;
>+	if (unshare_flags & ~(CLONE_THREAD|CLONE_FS|CLONE_NEWNS|CLONE_SIGHAND|
>+				CLONE_VM|CLONE_FILES|CLONE_SYSVSEM))
>+		goto bad_unshare_out;
> 
> 	if ((err = unshare_thread(unshare_flags)))
> 		goto bad_unshare_out;
>  
>