From: Christopher Lameter <cl@linux.com>
To: Igor Stoppa <igor.stoppa@huawei.com>
Cc: jglisse@redhat.com, keescook@chromium.org, mhocko@kernel.org,
labbott@redhat.com, hch@infradead.org, willy@infradead.org,
linux-security-module@vger.kernel.org, linux-mm@kvack.org,
linux-kernel@vger.kernel.org,
kernel-hardening@lists.openwall.com
Subject: Re: [PATCH 3/6] struct page: add field for vm_struct
Date: Fri, 2 Feb 2018 12:43:25 -0600 (CST) [thread overview]
Message-ID: <alpine.DEB.2.20.1802021240370.31548@nuc-kabylake> (raw)
In-Reply-To: <48fde114-d063-cfbf-e1b6-262411fcd963@huawei.com>
On Thu, 1 Feb 2018, Igor Stoppa wrote:
> > Would it not be better to use compound page allocations here?
> > page_head(whatever) gets you the head page where you can store all sorts
> > of information about the chunk of memory.
>
> Can you please point me to this function/macro? I don't seem to be able
> to find it, at least not in 4.15
Ok its compound_head(). See also the use in the SLAB and SLUB allocator.
> During hardened user copy permission check, I need to confirm if the
> memory range that would be exposed to userspace is a legitimate
> sub-range of a pmalloc allocation.
If you save the size in the head page struct then you could do that pretty
fast.
> I cannot comment on your proposal because I do not know where to find
> the reference you made, or maybe I do not understand what you mean :-(
compund pages are higher order pages that are handled as a single page by
the VM. See https://lwn.net/Articles/619514/
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next prev parent reply other threads:[~2018-02-02 18:43 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-01-30 15:14 [RFC PATCH v12 0/6] mm: security: ro protection for dynamic data Igor Stoppa
2018-01-30 15:14 ` [PATCH 1/6] genalloc: track beginning of allocations Igor Stoppa
2018-01-30 15:14 ` [PATCH 2/6] genalloc: selftest Igor Stoppa
2018-01-30 15:14 ` [PATCH 3/6] struct page: add field for vm_struct Igor Stoppa
2018-02-01 0:00 ` Christopher Lameter
2018-02-01 12:42 ` Igor Stoppa
2018-02-01 21:11 ` Kees Cook
2018-02-02 16:01 ` Igor Stoppa
2018-02-02 18:43 ` Christopher Lameter [this message]
2018-02-03 16:13 ` Igor Stoppa
2018-02-05 15:33 ` Christopher Lameter
2018-02-09 11:34 ` Igor Stoppa
2018-02-06 12:37 ` Matthew Wilcox
2018-02-09 13:45 ` Igor Stoppa
2018-01-30 15:14 ` [PATCH 4/6] Protectable Memory Igor Stoppa
2018-02-02 5:41 ` kbuild test robot
2018-02-02 5:53 ` kbuild test robot
2018-01-30 15:14 ` [PATCH 5/6] Documentation for Pmalloc Igor Stoppa
2018-01-30 17:08 ` Jonathan Corbet
2018-02-02 15:56 ` Igor Stoppa
2018-02-10 3:37 ` Matthew Wilcox
2018-02-12 15:28 ` Jonathan Corbet
2018-01-30 15:14 ` [PATCH 6/6] Pmalloc: self-test Igor Stoppa
2018-02-02 6:14 ` kbuild test robot
-- strict thread matches above, loose matches on Subject: below --
2018-02-12 16:52 [RFC PATCH v16 0/6] mm: security: ro protection for dynamic data Igor Stoppa
2018-02-12 16:52 ` [PATCH 3/6] struct page: add field for vm_struct Igor Stoppa
2018-02-11 3:19 [RFC PATCH v15 0/6] mm: security: ro protection for dynamic data Igor Stoppa
2018-02-11 3:19 ` [PATCH 3/6] struct page: add field for vm_struct Igor Stoppa
2018-02-11 21:16 ` Matthew Wilcox
2018-02-12 16:24 ` Igor Stoppa
2018-02-20 19:53 ` Igor Stoppa
2018-02-20 20:54 ` Matthew Wilcox
2018-02-21 12:01 ` Igor Stoppa
2018-02-22 14:20 ` Igor Stoppa
2018-02-04 16:47 [RFC PATCH v14 0/6] mm: security: ro protection for dynamic data Igor Stoppa
2018-02-04 16:47 ` [PATCH 3/6] struct page: add field for vm_struct Igor Stoppa
2018-02-03 19:42 [RFC PATCH v13 0/6] mm: security: ro protection for dynamic data Igor Stoppa
2018-02-03 19:42 ` [PATCH 3/6] struct page: add field for vm_struct Igor Stoppa
2018-01-24 17:56 [RFC PATCH v11 0/6] mm: security: ro protection for dynamic data Igor Stoppa
2018-01-24 17:56 ` [PATCH 3/6] struct page: add field for vm_struct Igor Stoppa
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