linux-kernel - Re: [RFC PATCH 1/3] asm-generic: io: Add exec versions of ioremap

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]

Date:	Wed, 18 May 2016 21:57:59 +0100
From:	Russell King - ARM Linux <linux@...linux.org.uk>
To:	Arnd Bergmann <arnd@...db.de>
Cc:	Dave Gerlach <d-gerlach@...com>,
	linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
	linux-omap@...r.kernel.org, Russ Dill <russ.dill@...com>,
	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	Shawn Guo <shawnguo@...nel.org>,
	Tony Lindgren <tony@...mide.com>,
	Alexandre Belloni <alexandre.belloni@...e-electrons.com>,
	Nishanth Menon <nm@...com>
Subject: Re: [RFC PATCH 1/3] asm-generic: io: Add exec versions of ioremap

On Wed, May 18, 2016 at 10:25:03PM +0200, Arnd Bergmann wrote:
> The ARM version of ioremap_exec() that gets added in this patch is cached
> (like memremap()), but then the asm-generic version is not? This is
> even more confusing, it should at least do roughly the same thing across
> architectures.
> 
> There should also be some documentation about what the expected behavior is, e.g.:
> 
> - is memremap_exec() by default cached or not? (I assume it would
>   be like memremap())
> - If we have an interface that does explicit uncached executable mapping,
>   what about architectures on which this is not possible? Should they
>   fall back to cached or non-executable, or cause a link error?  

Another important point is whether atomic instructions / kernel locks
can be located within the mapped memory.

-- 
RMK's Patch system: http://www.armlinux.org.uk/developer/patches/
FTTC broadband for 0.8mile line: currently at 9.6Mbps down 400kbps up
according to speedtest.net.