linux-kernel - Re: [PATCH v2] arch: Kconfig: Let all little endian architectures define CPU_LITTLE

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: <20140813050809.GB30459@ravnborg.org>
Date:	Wed, 13 Aug 2014 07:08:09 +0200
From:	Sam Ravnborg <sam@...nborg.org>
To:	Chen Gang <gang.chen.5i5j@...il.com>
Cc:	Arnd Bergmann <arnd@...db.de>, akpm@...ux-foundation.org,
	Geert Uytterhoeven <geert@...ux-m68k.org>,
	Jean Delvare <jdelvare@...e.de>, linux@....linux.org.uk,
	catalin.marinas@....com, will.deacon@....com, msalter@...hat.com,
	a-jacquiot@...com, tony.luck@...el.com, fenghua.yu@...el.com,
	tglx@...utronix.de, mingo@...hat.com, hpa@...or.com,
	x86@...nel.org, linux-arm-kernel@...ts.infradead.org,
	linux-c6x-dev@...ux-c6x.org, linux-ia64@...r.kernel.org,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	linux-arch@...r.kernel.org
Subject: Re: [PATCH v2] arch: Kconfig: Let all little endian architectures
 define CPU_LITTLE_ENDIAN explicitly

On Wed, Aug 13, 2014 at 06:48:35AM +0800, Chen Gang wrote:
> x86 and ia64 are always little endian. And another architectures may be
> little endian: mips, sh, powerpc, and m32r (may mark CPU_LITTLE_ENDIAN
> explicitly); also arm(64) and c6x (which may be !CPU_BIG_ENDIAN).
> 
> Some drivers (e.g. some of "drivers/isdn/hisax") may only support little
> endian (CPU_LITTLE_ENDIAN), and some drivers may only support big endian
> (!CPU_LITTLE_ENDIAN).
> 
> So export all little endian architectures within kernel wide, so can let
> Kconfig easier for the modules which only support little endian or only
> for big endian (assume !CPU_LITTLE_ENDIAN is same as CPU_BIG_ENDIAN).
We need to cover three cases here:
- An arch supports only little endian
- An arch supports only big endian
- An arch may be both little and big endian

The solution you suggest assumes that an arch is either little or big endian.
But we cannot ignore the hybriads that can do both.

	Sam
--
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/