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From:   Linus Torvalds <torvalds@linux-foundation.org>
Date:   Tue, 14 Jul 2020 09:10:48 -0700
Message-ID: <CAHk-=wjffJ=EBrLjsz=KUFyPXVQUO03L=VJmHnLhVr4XvT3Mpw@mail.gmail.com>
Subject: Re: WARNING: at mm/mremap.c:211 move_page_tables in i386
To:     Joel Fernandes <joel@joelfernandes.org>
Cc:     "Kirill A. Shutemov" <kirill@shutemov.name>,
        Naresh Kamboju <naresh.kamboju@linaro.org>,
        linux- stable <stable@vger.kernel.org>,
        open list <linux-kernel@vger.kernel.org>,
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        lkft-triage@lists.linaro.org, Chris Down <chris@chrisdown.name>,
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        Jerome Glisse <jglisse@redhat.com>,
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On Tue, Jul 14, 2020 at 9:08 AM Joel Fernandes <joel@joelfernandes.org> wrote:
>
> I was thinking we should not call move_page_tables() with overlapping ranges
> at all, just to keep things simple.

No, we're not breaking the existing stack movement code just to keep
things simple.

The rule is "make it as simple as possible, but no simpler".

And "as possible" in the case of Linux means "no breaking of old
interfaces". The stack randomization movement most certainly counts.

                  Linus