Subject: Re: RFC: disablenetwork facility. (v4)

From: Al Viro <[email-masked]>
Date: Sun, 27 Dec 2009 08:51:13 +0000

On Sun, Dec 27, 2009 at 05:36:48PM +0900, Tetsuo Handa wrote:

> Application writers know better what syscalls the application will call than
> application users.

Aren't you forgetting about libc?  Seriously, any interface along the
lines of "pass a set of syscall numbers to kernel" is DOA:
	* syscall numbers are architecture-dependent
	* there are socketcall-style multiplexors (sys_ipc, anyone?)
	* libc is free to substitute one for another
	* libc is free to do so in arch-specific manner
	* libc is free to do so in kernel-revision-specific manner
	* libc is free to do so in libc-revision-specific manner
(... and does all of the above)
	* new syscalls get added
	* e.g. on sparc64 32bit task can issue 64bit syscalls