Re: [PATCH v4 1/2] kernel: Implement selective syscall userspace redirection

[Kees Cook]

On Thu, Jul 16, 2020 at 10:06:01PM +0100, Matthew Wilcox wrote:
> On Thu, Jul 16, 2020 at 03:31:40PM -0400, Gabriel Krisman Bertazi wrote:
> > selector is an optional pointer to a char-sized userspace memory region
> > that has a key switch for the mechanism. This key switch is set to
> > either PR_SYS_DISPATCH_ON, PR_SYS_DISPATCH_OFF to enable and disable the
> > redirection without calling the kernel.
> > 
> > The feature is meant to be set per-thread and it is disabled on
> > fork/clone/execv.
> 
> Disabled on exec.  Disabled in the child on clone/fork (and vfork, I
> think).
> 
> That means we don't need to worry about it interacting badly with
> a setuid program, right?

Right, that's the intention.

-- 
Kees Cook