linux-kernel - Re: [PATCH v3 1/2] mm, proc: Fix region lost in /proc/self/smaps

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Message-ID: <20160923143907.GT4478@dhcp22.suse.cz>
Date:   Fri, 23 Sep 2016 16:39:08 +0200
From:   Michal Hocko <mhocko@...nel.org>
To:     Robert Ho <robert.hu@...el.com>
Cc:     pbonzini@...hat.com, akpm@...ux-foundation.org, oleg@...hat.com,
        dan.j.williams@...el.com, dave.hansen@...el.com,
        guangrong.xiao@...ux.intel.com, gleb@...nel.org,
        mtosatti@...hat.com, kvm@...r.kernel.org,
        linux-kernel@...r.kernel.org, stefanha@...hat.com,
        yuhuang@...hat.com, linux-mm@...ck.org,
        ross.zwisler@...ux.intel.com
Subject: Re: [PATCH v3 1/2] mm, proc: Fix region lost in /proc/self/smaps

On Fri 23-09-16 15:50:51, Michal Hocko wrote:
> On Fri 23-09-16 21:12:33, Robert Ho wrote:
[...]
> > @@ -786,7 +791,7 @@ static int show_smap(struct seq_file *m, void *v, int is_pid)
> >  		   "KernelPageSize: %8lu kB\n"
> >  		   "MMUPageSize:    %8lu kB\n"
> >  		   "Locked:         %8lu kB\n",
> > -		   (vma->vm_end - vma->vm_start) >> 10,
> > +		   (vma->vm_end - max(vma->vm_start, m->version)) >> 10,
> >  		   mss.resident >> 10,
> >  		   (unsigned long)(mss.pss >> (10 + PSS_SHIFT)),
> >  		   mss.shared_clean  >> 10,

And forgot to mention that this is not sufficient either. You also need
to restrict the pte walk to get sane numbers...
-- 
Michal Hocko
SUSE Labs