From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754173Ab1ETWNW (ORCPT ); Fri, 20 May 2011 18:13:22 -0400 Received: from smtp1.linux-foundation.org ([140.211.169.13]:39513 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752228Ab1ETWNQ (ORCPT ); Fri, 20 May 2011 18:13:16 -0400 Date: Fri, 20 May 2011 15:11:13 -0700 From: Andrew Morton To: Jean Delvare Cc: LKML Subject: Re: [PATCH] check_signature depends on CONFIG_CHECK_SIGNATURE Message-Id: <20110520151113.645dbbe7.akpm@linux-foundation.org> In-Reply-To: <20110520161448.375eb634@endymion.delvare> References: <20110520161448.375eb634@endymion.delvare> X-Mailer: Sylpheed 3.0.2 (GTK+ 2.20.1; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 20 May 2011 16:14:48 +0200 Jean Delvare wrote: > check_signature() is only available if CONFIG_CHECK_SIGNATURE has been > selected. Don't declare the function if it won't be available at link > time. That way, any failure to select CONFIG_CHECK_SIGNATURE as needed > will show up immediately at build time. > > Signed-off-by: Jean Delvare > --- > include/linux/io.h | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > --- linux-2.6.40-rc0.orig/include/linux/io.h 2011-05-20 10:41:02.000000000 +0200 > +++ linux-2.6.40-rc0/include/linux/io.h 2011-05-20 16:00:31.000000000 +0200 > @@ -63,8 +63,11 @@ void __iomem *devm_ioremap(struct device > void __iomem *devm_ioremap_nocache(struct device *dev, resource_size_t offset, > unsigned long size); > void devm_iounmap(struct device *dev, void __iomem *addr); > +void devm_ioremap_release(struct device *dev, void *res); > + > +#ifdef CONFIG_CHECK_SIGNATURE > int check_signature(const volatile void __iomem *io_addr, > const unsigned char *signature, int length); > -void devm_ioremap_release(struct device *dev, void *res); > +#endif We usually avoid doing this. Detecting the error at link time is sufficient. Yes, that will very occasionally cost a small number of people a little additional time. But we must balance that against permanently messing up the header files.