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Date:	Wed, 1 Jul 2009 20:19:34 +0100
From:	Ralf Baechle <ralf@linux-mips.org>
To:	Yong Zhang <yong.zhang@windriver.com>
Cc:	linux-kernel@vger.kernel.org, linux-mips@linux-mips.org
Subject: Re: [PATCH] MIPS: o32 application running on 64bit kernel core dump
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On Wed, Jul 01, 2009 at 09:35:39AM +0800, Yong Zhang wrote:

> +/* These MUST be defined before elf.h gets included */

This sort of ordering bug seems to become a tradition.  I think it may be
a good idea to insert a check like this:

#ifdef ELF_CORE_COPY_REGS
#error ELF_CORE_COPY_REGS should not be defined yet!
#endif

> +extern void elf32_core_copy_regs(elf_gregset_t grp, struct pt_regs *regs);
> +#define ELF_CORE_COPY_REGS(_dest, _regs) elf32_core_copy_regs(_dest, _regs);
> +#define ELF_CORE_COPY_TASK_REGS(_tsk, _dest)				\
> +({									\
> +	int __res = 1;							\
> +	elf32_core_copy_regs((*_dest), (task_pt_regs(_tsk)));		\

Be very careful with parentheses in macros.  This line should probably
become:

	elf32_core_copy_regs(*(_dest), task_pt_regs(_tsk));		\

The changes to the first argument to bullet prof the macro and the change
to the second one for cosmetic reasons.

  Ralf