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Date:   Wed, 17 Apr 2019 19:56:32 +0300
From:   Cyrill Gorcunov <gorcunov@gmail.com>
To:     Michal =?iso-8859-1?Q?Koutn=FD?= <mkoutny@suse.com>
Cc:     kbuild-all@01.org, Michael Kerrisk <mtk.manpages@gmail.com>,
        Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>,
        Randy Dunlap <rdunlap@infradead.org>,
        kbuild test robot <lkp@intel.com>,
        Michal Hocko <mhocko@kernel.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        Yang Shi <yang.shi@linux.alibaba.com>,
        Andrew Morton <akpm@linuxfoundation.org>,
        Andrey Vagin <avagin@openvz.org>,
        LKML <linux-kernel@vger.kernel.org>,
        Pavel Emelyanov <xemul@virtuozzo.com>
Subject: Re: [PATCH] prctl: Don't compile some of prctl functions when CRUI
Message-ID: <20190417165632.GC3040@uranus.lan>
References: <20180420140044.478b4c88d3cf238bd440f2a7@linux-foundation.org>
 <20190417122349.GA15498@blackbody.suse.cz>
 <20190417123841.GA3040@uranus.lan>
 <20190417144454.GG8962@blackbody.suse.cz>
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On Wed, Apr 17, 2019 at 04:44:54PM +0200, Michal Koutn? wrote:
> On Wed, Apr 17, 2019 at 03:38:41PM +0300, Cyrill Gorcunov <gorcunov@gmail.com> wrote:
> > I've a bit vague memory what we've ended up with, but iirc there was
> > a problem with brk() syscall or similar. Then I think we left everything
> > as is.
> Was this related to the removal of non PR_SET_MM_MAP operations too?
> Do you have any pointers to the topic?

Here some details: suprisingly there are already users of PR_SET_MM_x
operands, so we can't deprecate it (https://lkml.org/lkml/2018/5/6/127).
And then there was an attempt to change locks https://lore.kernel.org/patchwork/patch/
but since we're modifying mm-> entries we should gurd them against
simultaneous sys_brk call. Or I misunderstood you and you meant somthing
different?