From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chen Gang Subject: Re: [PATCH] arch: configuration, deleting 'CONFIG_BUG' since always need it. Date: Thu, 23 May 2013 19:19:30 +0800 Message-ID: <519DFB42.7010509@asianux.com> References: <519DCBEF.3090208@asianux.com> <201305231139.38233.arnd@arndb.de> <20130523100409.GK18614@n2100.arm.linux.org.uk> <201305231259.43750.arnd@arndb.de> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <201305231259.43750.arnd-r2nGTMty4D4@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: uclinux-dist-devel-bounces-ZG0+EudsQA8dtHy/vicBwGD2FQJk+8+b@public.gmane.org Errors-To: uclinux-dist-devel-bounces-ZG0+EudsQA8dtHy/vicBwGD2FQJk+8+b@public.gmane.org To: Arnd Bergmann Cc: Linux-sh list , Catalin Marinas , Benjamin Herrenschmidt , Heiko Carstens , "paulus-eUNUBHrolfbYtjvyW6yDsg@public.gmane.org" , "H. Peter Anvin" , Michel Lespinasse , Hans-Christian Egtvedt , Linux-Arch , linux-s390-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Russell King - ARM Linux , Yoshinori Sato , Richard Weinberger , Helge Deller , the arch/x86 maintainers , "James E.J. Bottomley" , "mingo-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org" , Geert Uytterhoeven , Frederic Weisbecker List-Id: linux-arch.vger.kernel.org On 05/23/2013 06:59 PM, Arnd Bergmann wrote: > You don't just want to avoid the code for printing the bug message and > the invalid instruction, we also want the compiler to not emit the > function call or check the enum for unexpected values. The meaning of > BUG() is really that person writing that statement was sure it cannot > happen unless there is a bug in the kernel, which has likely already > corrupted data. Printing a diagnostic at this point is nice if someone > is there to look at it, but letting the kernel do further actions that > may be undefined is not going to make things worse. So I think neither unreachable() nor panic() are suitable for this condition. I guess 'CONFIG_BUG' is not belong to common features, now (and in the future), so it is not suitable still exist in "asm-generic/bug.h", need remove it firstly. And then let the specific architectures to implement their own BUG(), if they want some special features. SO most of arches can skip this issue. Thanks. -- Chen Gang Asianux Corporation