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From: Segher Boessenkool <segher@kernel.crashing.org>
Subject: Re: [PATCH 1/3] powerpc,
	Makefile: Make it possible to safely select CONFIG_FRAME_POINTER
Date: Sat, 2 May 2009 21:48:08 +0200
To: Anton Vorontsov <avorontsov@ru.mvista.com>
Cc: linux-kernel@vger.kernel.org, linuxppc-dev@ozlabs.org,
	Steven Rostedt <srostedt@redhat.com>,
	Paul Mackerras <paulus@samba.org>, Ingo Molnar <mingo@elte.hu>,
	Sam Ravnborg <sam@ravnborg.org>
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> This patch introduces HAVE_NORMAL_FRAME_POINTER Kconfig symbol. When
> defined, the top level Makefile won't add -fno-omit-frame-pointer
> cflag (the flag is useless for PowerPC kernels, and also makes gcc
> generate wrong code).

> +++ b/arch/powerpc/Kconfig

> +	select HAVE_NORMAL_FRAME_POINTER

> +config HAVE_NORMAL_FRAME_POINTER
> +	bool
> +	help
> +	  Architectures should select this symbol if their ABI implies
> +	  having a frame pointer.

I am totally confused what you call a frame pointer here.
None of the relevant PowerPC ABIs have a frame pointer
separate from the stack pointer; the compiler can create
one, of course.  A better config symbol name and help text
would help understand this patch :-)


Segher