linux-kernel - Re: [PATCH v10 13/17] mm: vmalloc: add flag preventing guard hole allocation

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20150129151254.edc75e5ae20c3cafb55d88b1@linux-foundation.org>
Date:	Thu, 29 Jan 2015 15:12:54 -0800
From:	Andrew Morton <akpm@...ux-foundation.org>
To:	Andrey Ryabinin <a.ryabinin@...sung.com>
Cc:	linux-kernel@...r.kernel.org, Dmitry Vyukov <dvyukov@...gle.com>,
	Konstantin Serebryany <kcc@...gle.com>,
	Dmitry Chernenkov <dmitryc@...gle.com>,
	Andrey Konovalov <adech.fo@...il.com>,
	Yuri Gribov <tetra2005@...il.com>,
	Konstantin Khlebnikov <koct9i@...il.com>,
	Sasha Levin <sasha.levin@...cle.com>,
	Christoph Lameter <cl@...ux.com>,
	Joonsoo Kim <iamjoonsoo.kim@....com>,
	Dave Hansen <dave.hansen@...el.com>,
	Andi Kleen <andi@...stfloor.org>, x86@...nel.org,
	linux-mm@...ck.org
Subject: Re: [PATCH v10 13/17] mm: vmalloc: add flag preventing guard hole
 allocation

On Thu, 29 Jan 2015 18:11:57 +0300 Andrey Ryabinin <a.ryabinin@...sung.com> wrote:

> For instrumenting global variables KASan will shadow memory
> backing memory for modules. So on module loading we will need
> to allocate shadow memory and map it at exact virtual address.

I don't understand.  What does "map it at exact virtual address" mean?

> __vmalloc_node_range() seems like the best fit for that purpose,
> except it puts a guard hole after allocated area.

Why is the guard hole a problem?

More details needed in this changelog, please.


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/