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Date: Wed, 1 Jul 2015 17:46:23 +0200
From: Oleg Nesterov <oleg@redhat.com>
To: David Rientjes <rientjes@google.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
        Al Viro <viro@zeniv.linux.org.uk>, Benjamin LaHaise <bcrl@kvack.org>,
        Hugh Dickins <hughd@google.com>, Jeff Moyer <jmoyer@redhat.com>,
        Kirill Shutemov <kirill.shutemov@linux.intel.com>,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/4] mremap: don't leak new_vma if f_op->mremap() fails
Message-ID: <20150701154623.GA14934@redhat.com>
References: <20150619231913.GA25877@redhat.com> <alpine.DEB.2.10.1506301530300.24266@chino.kir.corp.google.com>
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On 06/30, David Rientjes wrote:
>
> On Sat, 20 Jun 2015, Oleg Nesterov wrote:
>
> > move_vma() can't just return if f_op->mremap() fails, we should
> > unmap the new vma like we do if move_page_tables() fails. To avoid
> > the code duplication this patch moves the "move entries back" under
> > the new "if (err)" branch.
> >
> > Signed-off-by: Oleg Nesterov <oleg@redhat.com>
>
> Looks good!  I think it was sniped by commit 4abad2ca4a4d ("mm: new
> arch_remap() hook")

No, it was b2edffdd912b "fix mremap() vs. ioctx_kill() race"

> so it needs to be rebased,

Yes, thanks, I'll rebase...

But you know, I think 4abad2ca4a4d ("mm: new arch_remap() hook") should
be reverted later. Please see

	[PATCH v2 1/1] mm: move ->mremap() from file_operations to vm_operations_struct
	http://marc.info/?l=linux-kernel&m=143526519407521

I think arch_remap() should be turned into special_mapping_vmops->nremap().
But this is off-topic right now.

> but after that feel free to add my
>
 	Acked-by: David Rientjes <rientjes@google.com>

Thanks!

Oleg.