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Date:   Wed, 16 Jan 2019 12:18:11 +0000
From:   Kevin Easton <kevin@guarana.org>
To:     Josh Snyder <joshs@netflix.com>
Cc:     Dominique Martinet <asmadeus@codewreck.org>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Andy Lutomirski <luto@amacapital.net>,
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        kernel list <linux-kernel@vger.kernel.org>,
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Subject: Re: [PATCH] mm/mincore: allow for making sys_mincore() privileged
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On Tue, Jan 15, 2019 at 11:52:25PM -0800, Josh Snyder wrote:
> On Tue, Jan 15, 2019 at 10:34 PM Dominique Martinet <asmadeus@codewreck.org>
> wrote:
> >
> > There is a difference with your previous patch though, that used to list no
> > page in core when it didn't know; this patch lists pages as in core when it
> > refuses to tell. I don't think that's very important, though.
> 
> Is there a reason not to return -EPERM in this case?

When I was looking through the Debian Code Search results, quite a few
of the hits were for code that uses mincore() as a way to check if
_anything_ is mapped at an address or not.  This code doesn't care about
the in core / not in core result of mincore(), just whether it returned
an error or not.

I think a new error return would break most of the instances of that
code I saw.

    - Kevin