linux-kernel - Re: [PATCH v2 03/31] arm64: Exception handling

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: <201208151303.47743.arnd@arndb.de>
Date:	Wed, 15 Aug 2012 13:03:47 +0000
From:	Arnd Bergmann <arnd@...db.de>
To:	Catalin Marinas <catalin.marinas@....com>
Cc:	linux-arch@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
	linux-kernel@...r.kernel.org, Will Deacon <will.deacon@....com>
Subject: Re: [PATCH v2 03/31] arm64: Exception handling

On Tuesday 14 August 2012, Catalin Marinas wrote:

> +#ifdef CONFIG_AARCH32_EMULATION
> +#define compat_thumb_mode(regs) \
> +	(((regs)->pstate & COMPAT_PSR_T_BIT))
> +#else
> +#define compat_thumb_mode(regs) (0)
> +#endif

The symbol we use on other platforms is CONFIG_COMPAT. I don't think you
need to have a separate CONFIG_AARCH32_EMULATION

> +void __bad_xchg(volatile void *ptr, int size)
> +{
> +	printk("xchg: bad data size: pc 0x%p, ptr 0x%p, size %d\n",
> +		__builtin_return_address(0), ptr, size);
> +	BUG();
> +}
> +EXPORT_SYMBOL(__bad_xchg);
> +

I think we're better off not defining this function. My guess is that
initially the idea on ARM was that it was meant as a BUILD_BUG_ON
replacement, but the someone added this function. And you copied it.

Microblaze has the same declaration, but (correctly) misses the
definition, which produces a much more helpful link failure than
a run-time BUG(). Using BUILD_BUG_ON would be even better.

	Arnd
--
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/