linux-kernel - Re: [PATCH 25/43] x86/mm/kaiser: Unmap kernel from userspace page tables (core patch)

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Message-ID: <20171124121638.ej2flgfvctw2cqer@hirez.programming.kicks-ass.net>
Date:   Fri, 24 Nov 2017 13:16:38 +0100
From:   Peter Zijlstra <peterz@...radead.org>
To:     Ingo Molnar <mingo@...nel.org>
Cc:     linux-kernel@...r.kernel.org,
        Dave Hansen <dave.hansen@...ux.intel.com>,
        Andy Lutomirski <luto@...capital.net>,
        Thomas Gleixner <tglx@...utronix.de>,
        "H . Peter Anvin" <hpa@...or.com>, Borislav Petkov <bp@...en8.de>,
        Linus Torvalds <torvalds@...ux-foundation.org>
Subject: Re: [PATCH 25/43] x86/mm/kaiser: Unmap kernel from userspace page
 tables (core patch)

On Fri, Nov 24, 2017 at 10:14:30AM +0100, Ingo Molnar wrote:
> +The minimalistic kernel portion of the user page tables try to
> +map only what is needed to enter/exit the kernel such as the
> +entry/exit functions themselves and the interrupt descriptor
> +table (IDT).  

                There are a few unnecessary things that get mapped
> +such as the first C function when entering an interrupt (see
> +comments in kaiser.c).

If I understood Andy's patches correctly, this should no longer be
required. Is this text still correct?