linux-kernel - Re: [PATCH] include/asm-generic/io.h: add 'UML' case just like 'no-MMU'

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: <51CABBDD.403@asianux.com>
Date:	Wed, 26 Jun 2013 18:01:01 +0800
From:	Chen Gang <gang.chen@...anux.com>
To:	Geert Uytterhoeven <geert@...ux-m68k.org>
CC:	Richard Weinberger <richard@....at>, Jeff Dike <jdike@...toit.com>,
	Arnd Bergmann <arnd@...db.de>,
	David Sharp <dhsharp@...gle.com>,
	"sfr@...b.auug.org.au" <sfr@...b.auug.org.au>,
	Steven Rostedt <rostedt@...dmis.org>,
	Ingo Molnar <mingo@...nel.org>,
	uml-devel <user-mode-linux-devel@...ts.sourceforge.net>,
	uml-user <user-mode-linux-user@...ts.sourceforge.net>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	Linux-Arch <linux-arch@...r.kernel.org>,
	Mark Brown <broonie@...nel.org>
Subject: Re: [PATCH] include/asm-generic/io.h: add 'UML' case just like 'no-MMU'

On 06/26/2013 05:48 PM, Geert Uytterhoeven wrote:
> On Wed, Jun 26, 2013 at 11:38 AM, Richard Weinberger <richard@....at> wrote:
>>> >> Since the API itself already contents the meaning: "return NULL means
>>> >> the arch has no related io memory",
> No, NULL means it could not map the I/O memory.
> 

"it could not map the I/O memory" includes "has no related io memory".
So it is enough for our case.

>>> >> Why not define a generic dummy one in "include/asm-generic/io.h" instead
>>> >> of "HAS_IOMEM" (which has already spread many various places, and also,
>>> >> most of new drivers have to know about it).
>>> >>
>>> >> e.g: in "include/asm-generic/io.h", if "CONFIG_HAS_IOMEM=n", define a
>>> >> dummy ioremap() which return NULL ... (also need consider more details).
>> >
>> > Because we don't even want to build these drivers and not make them fail while
>> > executing io memory related functions.
> Indeed, it doesn't make sense to build drivers that cannot work.
> And they may fail in a very bad way.

That is our 'platform' guys feeling, not the 'module' guys, as
'platform' guys, it is better to provide the choice to 'module' guys,
and let them decide by themselves, not forced by us.


Thanks.
-- 
Chen Gang

Asianux Corporation
--
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/