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From:   Florent Revest <revest@chromium.org>
Date:   Tue, 3 Oct 2023 17:52:38 +0200
Message-ID: <CABRcYmJpSAppk315vzitO9N-D=p7sJ+QiKWtA6w5mEven=Cm6A@mail.gmail.com>
Subject: Re: [PATCH v4 5/6] mm: Add a NO_INHERIT flag to the PR_SET_MDWE prctl
To:     Andrew Morton <akpm@linux-foundation.org>
Cc:     linux-kernel@vger.kernel.org, linux-mm@kvack.org,
        catalin.marinas@arm.com, anshuman.khandual@arm.com,
        joey.gouly@arm.com, mhocko@suse.com, keescook@chromium.org,
        david@redhat.com, peterx@redhat.com, izbyshev@ispras.ru,
        broonie@kernel.org, szabolcs.nagy@arm.com, kpsingh@kernel.org,
        gthelen@google.com, toiwoton@gmail.com, ayush.jain3@amd.com
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On Fri, Sep 22, 2023 at 3:33=E2=80=AFAM Andrew Morton <akpm@linux-foundatio=
n.org> wrote:
>
> On Mon, 28 Aug 2023 17:08:57 +0200 Florent Revest <revest@chromium.org> w=
rote:
>
> > This extends the current PR_SET_MDWE prctl arg with a bit to indicate
> > that the process doesn't want MDWE protection to propagate to children.
> >
> > To implement this no-inherit mode, the tag in current->mm->flags must b=
e
> > absent from MMF_INIT_MASK. This means that the encoding for "MDWE but
> > without inherit" is different in the prctl than in the mm flags. This
> > leads to a bit of bit-mangling in the prctl implementation.
>
> Is a manpage update planned?

Ah that's a good point, I didn't think about it, thank you.

> And did we update the manpage for PR_SET_MDWE?

No we didn't but I sent a patch to man-pages here:
https://lore.kernel.org/linux-man/20231003155010.3651349-1-revest@chromium.=
org/