From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sasha Levin Subject: Re: [PATCH] ARM: EXYNOS: use BUG_ON where possible Date: Mon, 12 Nov 2012 10:25:54 -0500 Message-ID: <50A11502.5060306@oracle.com> References: <1352406191-14303-1-git-send-email-sasha.levin@oracle.com> <1352406191-14303-5-git-send-email-sasha.levin@oracle.com> <50A111DD.6080504@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: Received: from aserp1040.oracle.com ([141.146.126.69]:17620 "EHLO aserp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752097Ab2KLP0s (ORCPT ); Mon, 12 Nov 2012 10:26:48 -0500 In-Reply-To: <50A111DD.6080504@gmail.com> Sender: linux-samsung-soc-owner@vger.kernel.org List-Id: linux-samsung-soc@vger.kernel.org To: Maarten Lankhorst Cc: linux-kernel@vger.kernel.org, Kukjin Kim , Russell King , linux-arm-kernel@lists.infradead.org, linux-samsung-soc@vger.kernel.org On 11/12/2012 10:12 AM, Maarten Lankhorst wrote: > Op 08-11-12 21:23, Sasha Levin schreef: >> Just use BUG_ON() instead of constructions such as: >> >> if (...) >> BUG() >> >> A simplified version of the semantic patch that makes this transformation >> is as follows: (http://coccinelle.lip6.fr/) >> >> // >> @@ >> expression e; >> @@ >> - if (e) BUG(); >> + BUG_ON(e); >> // >> >> Signed-off-by: Sasha Levin >> --- >> arch/arm/mach-exynos/common.c | 6 ++---- >> 1 file changed, 2 insertions(+), 4 deletions(-) >> >> diff --git a/arch/arm/mach-exynos/common.c b/arch/arm/mach-exynos/common.c >> index 4e577f6..6a55a5a 100644 >> --- a/arch/arm/mach-exynos/common.c >> +++ b/arch/arm/mach-exynos/common.c >> @@ -465,10 +465,8 @@ static void __init combiner_cascade_irq(unsigned int combiner_nr, unsigned int i >> else >> max_nr = EXYNOS4_MAX_COMBINER_NR; >> >> - if (combiner_nr >= max_nr) >> - BUG(); >> - if (irq_set_handler_data(irq, &combiner_data[combiner_nr]) != 0) >> - BUG(); >> + BUG_ON(combiner_nr >= max_nr); >> + BUG_ON(irq_set_handler_data(irq, &combiner_data[combiner_nr]) != 0); > Is it really a good idea to put functions that perform work in a BUG_ON? > I don't know, but for some reason it just feels wrong. I'd expect code to > compile fine if BUG_ON was a noop, so doing verification calls only, not > actual work.. You can't modify the side-effects of a macro based on kernel configuration. If we're evaluating the expression when BUG_ON() is enabled, you must also evaluate the expression when BUG_ON() is not enabled (HAVE_ARCH_BUG_ON is not set). The only reason I'd not include function calls in a BUG_ON() call is due to readability considerations. In this case it looked okay to me, but if someone thinks that getting the function call into the BUG_ON() complicated things I'm fine with skipping that. Thanks, Sasha From mboxrd@z Thu Jan 1 00:00:00 1970 From: sasha.levin@oracle.com (Sasha Levin) Date: Mon, 12 Nov 2012 10:25:54 -0500 Subject: [PATCH] ARM: EXYNOS: use BUG_ON where possible In-Reply-To: <50A111DD.6080504@gmail.com> References: <1352406191-14303-1-git-send-email-sasha.levin@oracle.com> <1352406191-14303-5-git-send-email-sasha.levin@oracle.com> <50A111DD.6080504@gmail.com> Message-ID: <50A11502.5060306@oracle.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 11/12/2012 10:12 AM, Maarten Lankhorst wrote: > Op 08-11-12 21:23, Sasha Levin schreef: >> Just use BUG_ON() instead of constructions such as: >> >> if (...) >> BUG() >> >> A simplified version of the semantic patch that makes this transformation >> is as follows: (http://coccinelle.lip6.fr/) >> >> // >> @@ >> expression e; >> @@ >> - if (e) BUG(); >> + BUG_ON(e); >> // >> >> Signed-off-by: Sasha Levin >> --- >> arch/arm/mach-exynos/common.c | 6 ++---- >> 1 file changed, 2 insertions(+), 4 deletions(-) >> >> diff --git a/arch/arm/mach-exynos/common.c b/arch/arm/mach-exynos/common.c >> index 4e577f6..6a55a5a 100644 >> --- a/arch/arm/mach-exynos/common.c >> +++ b/arch/arm/mach-exynos/common.c >> @@ -465,10 +465,8 @@ static void __init combiner_cascade_irq(unsigned int combiner_nr, unsigned int i >> else >> max_nr = EXYNOS4_MAX_COMBINER_NR; >> >> - if (combiner_nr >= max_nr) >> - BUG(); >> - if (irq_set_handler_data(irq, &combiner_data[combiner_nr]) != 0) >> - BUG(); >> + BUG_ON(combiner_nr >= max_nr); >> + BUG_ON(irq_set_handler_data(irq, &combiner_data[combiner_nr]) != 0); > Is it really a good idea to put functions that perform work in a BUG_ON? > I don't know, but for some reason it just feels wrong. I'd expect code to > compile fine if BUG_ON was a noop, so doing verification calls only, not > actual work.. You can't modify the side-effects of a macro based on kernel configuration. If we're evaluating the expression when BUG_ON() is enabled, you must also evaluate the expression when BUG_ON() is not enabled (HAVE_ARCH_BUG_ON is not set). The only reason I'd not include function calls in a BUG_ON() call is due to readability considerations. In this case it looked okay to me, but if someone thinks that getting the function call into the BUG_ON() complicated things I'm fine with skipping that. Thanks, Sasha