Re: [patch 7/8] fdmap v2 - implement sys_socket2

[Jeff Dike <jdike@addtoit.com>]

On Thu, Jun 07, 2007 at 01:10:23PM -0700, Linus Torvalds wrote:
> HOWEVER.
> 
> I think we could introduce a *single* new system call, which does 
> basically a "run the specified system call with the following flags".

As long as we are considering indirecting system calls, how about
reviving your proposal to run a system call in a different address
space:
	http://www.ussg.iu.edu/hypermail/linux/kernel/0212.3/0502.html

UML could make good use of the ability to remotely manipulate address
spaces.  I never liked any of the proposed interfaces very much,
including mm_indirect.  However, if my tastebuds are defective, and
indirecting system calls is the way to solve a family of problems,
then we should look at fitting in mm_indirect.

> It has the disadvantage that it would need some per-architecture setup to 
> load the actual real arguments from memory: the system call would probably 
> look something like
> 
> 	syscall_indirect(unsigned long flags, sigset_t *, 
> 			 int syscall, unsigned long args[6]);

mm_indirect would need a file descriptor to the other address space,
which we would presumably get from a new get_mm() system call.

				Jeff

-- 
Work email - jdike at linux dot intel dot com