From: Joe Perches <joe@perches.com>
To: Michal Hocko <mhocko@kernel.org>
Cc: linux-kernel@vger.kernel.org,
Andrew Morton <akpm@linux-foundation.org>,
Jann Horn <jann@thejh.net>,
linux-mm@kvack.org
Subject: Re: [PATCH 2/2] proc: task_mmu: Reduce output processing cpu time
Date: Mon, 22 Aug 2016 01:30:14 -0700 [thread overview]
Message-ID: <1471854614.3746.46.camel@perches.com> (raw)
In-Reply-To: <1471852859.3746.42.camel@perches.com>
On Mon, 2016-08-22 at 01:00 -0700, Joe Perches wrote:
> On Mon, 2016-08-22 at 09:24 +0200, Michal Hocko wrote:
> > On Sat 20-08-16 01:00:17, Joe Perches wrote:
[]
> > > static int proc_maps_open(struct inode *inode, struct file *file,
> > > const struct seq_operations *ops, int psize)
> > > {
> > > - struct proc_maps_private *priv = __seq_open_private(file, ops, psize);
> > > + struct proc_maps_private *priv;
> > > + struct mm_struct *mm;
> > > +
> > > + mm = proc_mem_open(inode, PTRACE_MODE_READ);
> > > + if (IS_ERR(mm))
> > > + return PTR_ERR(mm);
> > >
> > > + priv = __seq_open_private_bufsize(file, ops, psize,
> > > + mm && mm->map_count ?
> > > + mm->map_count * 0x300 : PAGE_SIZE);
> > NAK to this!
> >
> > Seriously, this just gives any random user access to user
> > defined amount of memory which not accounted, not reclaimable and a
> > potential consumer of any higher order blocks.
> I completely disagree here with your rationale here.
And with further review and your comment above, I withdraw this patch.
cheers, Joe
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next prev parent reply other threads:[~2016-08-22 8:30 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-08-18 11:31 [PATCH] proc, smaps: reduce printing overhead Michal Hocko
2016-08-18 13:26 ` Joe Perches
2016-08-18 14:26 ` Michal Hocko
2016-08-18 14:41 ` Joe Perches
2016-08-18 14:41 ` Michal Hocko
2016-08-18 14:46 ` Joe Perches
2016-08-18 14:58 ` Michal Hocko
2016-08-18 15:23 ` Joe Perches
2016-08-18 16:42 ` Michal Hocko
2016-08-19 10:12 ` [PATCH 0/2] fs, proc: optimize smaps output formatting Michal Hocko
2016-08-19 10:12 ` [PATCH 1/2] proc, meminfo: abstract show_val_kb Michal Hocko
2016-08-26 2:54 ` [lkp] [proc, meminfo] dd3b422c11: stderr.Signal#(FPE)caught_by_ps(procps-ng_version#) kernel test robot
2016-08-19 10:13 ` [PATCH 2/2] proc, smaps: reduce printing overhead Michal Hocko
2016-08-19 17:43 ` [PATCH 0/2] fs, proc: optimize smaps output formatting Joe Perches
2016-08-19 20:18 ` Joe Perches
2016-08-20 7:29 ` Michal Hocko
2016-08-20 7:55 ` Joe Perches
2016-08-20 8:00 ` [PATCH 0/2] seq: Speed up /proc/<pid>/smaps Joe Perches
2016-08-20 8:00 ` [PATCH 1/2] seq_file: Add __seq_open_private_bufsize for seq file_operation sizes Joe Perches
2016-08-20 8:00 ` [PATCH 2/2] proc: task_mmu: Reduce output processing cpu time Joe Perches
2016-08-22 7:24 ` Michal Hocko
2016-08-22 8:00 ` Joe Perches
2016-08-22 8:30 ` Joe Perches [this message]
2016-08-22 12:09 ` Michal Hocko
2016-08-23 15:14 ` [PATCH] proc, smaps: reduce printing overhead Michal Hocko
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