From: Andy Lutomirski <luto@amacapital.net>
To: Matthew Wilcox <matthew.r.wilcox@intel.com>
Cc: Ingo Molnar <mingo@redhat.com>,
Matthew Wilcox <willy@linux.intel.com>,
Kees Cook <keescook@chromium.org>,
Andrew Morton <akpm@linux-foundation.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"linux-mm@kvack.org" <linux-mm@kvack.org>
Subject: Re: [PATCH 1/3] x86: Honour passed pgprot in track_pfn_insert() and track_pfn_remap()
Date: Mon, 25 Jan 2016 09:33:35 -0800 [thread overview]
Message-ID: <CALCETrWNx=H=u2R+JKM6Dr3oMqeiBSS+hdrYrGT=BJ-JrEyL+w@mail.gmail.com> (raw)
In-Reply-To: <1453742717-10326-2-git-send-email-matthew.r.wilcox@intel.com>
On Mon, Jan 25, 2016 at 9:25 AM, Matthew Wilcox
<matthew.r.wilcox@intel.com> wrote:
> From: Matthew Wilcox <willy@linux.intel.com>
>
> track_pfn_insert() overwrites the pgprot that is passed in with a value
> based on the VMA's page_prot. This is a problem for people trying to
> do clever things with the new vm_insert_pfn_prot() as it will simply
> overwrite the passed protection flags. If we use the current value of
> the pgprot as the base, then it will behave as people are expecting.
>
> Also fix track_pfn_remap() in the same way.
Well that's embarrassing. Presumably it worked for me because I only
overrode the cacheability bits and lookup_memtype did the right thing.
But shouldn't the PAT code change the memtype if vm_insert_pfn_prot
requests it? Or are there no callers that actually need that? (HPET
doesn't, because there's a plain old ioremapped mapping.)
--Andy
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next prev parent reply other threads:[~2016-01-25 17:33 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-01-25 17:25 [PATCH 0/3] Fixes for vm_insert_pfn_prot() Matthew Wilcox
2016-01-25 17:25 ` [PATCH 1/3] x86: Honour passed pgprot in track_pfn_insert() and track_pfn_remap() Matthew Wilcox
2016-01-25 17:33 ` Andy Lutomirski [this message]
2016-01-25 17:46 ` Andy Lutomirski
2016-01-27 4:40 ` Matthew Wilcox
2016-01-27 5:44 ` Andy Lutomirski
2016-01-29 14:49 ` Matthew Wilcox
2016-01-29 22:19 ` Andy Lutomirski
2016-02-09 14:24 ` Ingo Molnar
2016-02-10 3:06 ` Andy Lutomirski
2016-01-25 17:25 ` [PATCH 2/3] mm: Convert vm_insert_pfn_prot to vmf_insert_pfn_prot Matthew Wilcox
2016-01-25 17:35 ` Andy Lutomirski
2016-01-27 4:18 ` Matthew Wilcox
2016-01-25 17:25 ` [PATCH 3/3] dax: Handle write faults more efficiently Matthew Wilcox
2016-01-25 17:38 ` Andy Lutomirski
2016-01-27 4:17 ` Matthew Wilcox
2016-01-27 5:22 ` Andy Lutomirski
2016-01-27 6:01 ` Andy Lutomirski
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