Date: Thu, 7 Sep 2017 12:44:14 -0600
From: Tycho Andersen <tycho@docker.com>
To: Christoph Hellwig <hch@infradead.org>
Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org,
        kernel-hardening@lists.openwall.com,
        Marco Benatto <marco.antonio.780@gmail.com>,
        Juerg Haefliger <juerg.haefliger@canonical.com>,
        Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Subject: Re: [PATCH v6 04/11] swiotlb: Map the buffer if it was unmapped by
 XPFO
Message-ID: <20170907184414.ow7av6wt5vht6pnd@docker>
References: <20170907173609.22696-1-tycho@docker.com>
 <20170907173609.22696-5-tycho@docker.com>
 <20170907181015.GA9557@infradead.org>
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On Thu, Sep 07, 2017 at 11:10:15AM -0700, Christoph Hellwig wrote:
> > -	if (PageHighMem(pfn_to_page(pfn))) {
> > +	if (PageHighMem(page) || xpfo_page_is_unmapped(page)) {
> 
> Please don't sprinkle xpfo details over various bits of code.
> 
> Just add a helper with a descriptive name, e.g.
> 
> page_is_unmapped()
> 
> that also includes the highmem case, as that will easily document
> what this check is doing.

Will do, thanks.

Patch 7 has a similar feel to this one, I can add a wrapper around
__clean_dcache_area_pou() if that makes sense?

Tycho