Re: [PATCH v2 05/17] x86/ldt: Prevent ldt inheritance on exec

[Andy Lutomirski]

On Thu, Dec 14, 2017 at 3:27 AM, Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote:
> From: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
>
> The LDT is inheritet independent of fork or exec, but that makes no sense
> at all because exec is supposed to start the process clean.
>
> The reason why this happens is that init_new_context_ldt() is called from
> init_new_context() which obviously needs to be called for both fork() and
> exec().
>
> It would be surprising if anything relies on that behaviour, so it seems to
> be safe to remove that misfeature.
>
> Split the context initialization into two parts. Clear the ldt pointer and
> initialize the mutex from the general context init and move the LDT
> duplication to arch_dup_mmap() which is only called on fork().

I like this one.