From: Tejun Heo <tj@kernel.org>
To: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: hpa@zytor.com, tglx@linutronix.de, mingo@elte.hu,
linux-kernel@vger.kernel.org, x86@kernel.org,
rusty@rustcorp.com.au
Subject: Re: [PATCH 08/11] x86: use asm .macro instead of cpp #define in entry_32.S
Date: Tue, 10 Feb 2009 10:14:11 +0900 [thread overview]
Message-ID: <4990D4E3.1010109@kernel.org> (raw)
In-Reply-To: <4990774E.5080206@goop.org>
Jeremy Fitzhardinge wrote:
> Tejun Heo wrote:
>> Impact: cleanup
>>
>> Use .macro instead of cpp #define where approriate. This cleans up
>> code and will ease future changes.
>>
>
> I agree with this in principle - cpp macros are indeed very ugly - but
> in practise I've found asm macros to be very hard to work with. When
> things go wrong, the gas error messages are completely useless (it only
> reports the error on the line where the macro was used, without any
> detail about where in the macro the problem lies), and as far as I know,
> there's no way to see the source with macros expanded.
Hmm... I originally did the conversion because I had some .if trick in
SAVE_ALL which got removed later. Even after the removal, it
generally looked like a good idea as x86_64 asm was primarily using
.macro too. I do like being able to see the post-processing output of
cpp too but for assembler disassembling the output often seem to give
enough clue, so I don't think it's a deal breaker. So, lacking
decisive technical merit either way, I was aiming for consistency with
x86_64 (and I already had the patch in queue so...).
Ingo, what do you think?
Thanks.
--
tejun
next prev parent reply other threads:[~2009-02-10 1:14 UTC|newest]
Thread overview: 48+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-02-09 13:39 [PATCHSET x86/master] add stack protector support for x86_32 Tejun Heo
2009-02-09 13:39 ` [PATCH 01/11] x86: include correct %gs in a.out core dump Tejun Heo
2009-02-09 17:12 ` Jeremy Fitzhardinge
2009-02-09 13:39 ` [PATCH 02/11] x86: math_emu info cleanup Tejun Heo
2009-02-09 13:42 ` Ingo Molnar
2009-02-09 13:45 ` Ingo Molnar
2009-02-09 13:52 ` Tejun Heo
2009-02-09 13:39 ` [PATCH 03/11] x86: fix math_emu register frame access Tejun Heo
2009-02-09 17:13 ` Brian Gerst
2009-02-09 23:40 ` Ingo Molnar
2009-02-10 1:08 ` Tejun Heo
2009-02-09 13:39 ` [PATCH 04/11] elf: add ELF_CORE_COPY_KERNEL_REGS() Tejun Heo
2009-02-09 13:39 ` [PATCH 05/11] x86: stackprotector.h misc update Tejun Heo
2009-02-09 13:39 ` [PATCH 06/11] stackprotector: update make rules Tejun Heo
2009-02-09 13:39 ` [PATCH 07/11] x86: no stack protector for vdso Tejun Heo
2009-02-09 13:39 ` [PATCH 08/11] x86: use asm .macro instead of cpp #define in entry_32.S Tejun Heo
2009-02-09 18:34 ` Jeremy Fitzhardinge
2009-02-10 1:14 ` Tejun Heo [this message]
2009-02-10 1:18 ` Jeremy Fitzhardinge
2009-02-10 11:11 ` Ingo Molnar
2009-02-09 13:39 ` [PATCH 09/11] x86: add %gs accessors for x86_32 Tejun Heo
2009-02-09 13:39 ` [PATCH 10/11] x86: make lazy %gs optional on x86_32 Tejun Heo
2009-02-09 18:12 ` Jeremy Fitzhardinge
2009-02-10 1:27 ` Tejun Heo
2009-02-10 1:51 ` Jeremy Fitzhardinge
2009-02-09 13:39 ` [PATCH 11/11] x86: implement x86_32 stack protector Tejun Heo
2009-02-10 15:25 ` Brian Gerst
2009-02-10 15:39 ` Tejun Heo
2009-02-11 7:31 ` [PATCH x86#core/percpu] x86: fix x86_32 stack protector bugs Tejun Heo
2009-02-11 10:34 ` Ingo Molnar
2009-02-11 14:18 ` Tejun Heo
2009-02-09 13:55 ` [PATCHSET x86/master] add stack protector support for x86_32 Ingo Molnar
2009-02-09 14:06 ` Ingo Molnar
2009-02-09 20:30 ` Ingo Molnar
2009-02-10 13:56 ` Tejun Heo
2009-02-10 14:16 ` Ingo Molnar
2009-02-09 14:12 ` Ingo Molnar
2009-02-10 13:54 ` Tejun Heo
2009-02-10 14:16 ` Tejun Heo
2009-02-10 14:20 ` Ingo Molnar
2009-02-10 14:26 ` Tejun Heo
2009-02-11 10:57 ` Ingo Molnar
2009-02-11 11:18 ` [PATCH] stackprotector: fix multi-word cross-builds Ingo Molnar
2009-02-11 14:19 ` Tejun Heo
2009-02-10 14:19 ` [PATCHSET x86/master] add stack protector support for x86_32 Ingo Molnar
2009-02-09 14:09 ` Brian Gerst
2009-02-09 14:15 ` Ingo Molnar
2009-02-10 1:36 ` Tejun Heo
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