From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754673AbbLVRUl (ORCPT ); Tue, 22 Dec 2015 12:20:41 -0500 Received: from prv-mh.provo.novell.com ([137.65.248.74]:36158 "EHLO prv-mh.provo.novell.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754181AbbLVRUj convert rfc822-to-8bit (ORCPT ); Tue, 22 Dec 2015 12:20:39 -0500 Message-Id: <5679947402000078000C2691@prv-mh.provo.novell.com> X-Mailer: Novell GroupWise Internet Agent 14.2.0 Date: Tue, 22 Dec 2015 10:20:36 -0700 From: "Jan Beulich" To: "Borislav Petkov" Cc: , , , Subject: Re: [PATCH] x86/ucode: replace redundant string literals References: <56797D0B02000078000C24EC@prv-mh.provo.novell.com> <20151222170714.GD3961@pd.tnic> In-Reply-To: <20151222170714.GD3961@pd.tnic> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 8BIT Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org >>> On 22.12.15 at 18:07, wrote: > On Tue, Dec 22, 2015 at 08:40:43AM -0700, Jan Beulich wrote: >> This doesn't just eliminate needless redundancy >> (plus avoid a possible disconnect if one string instance gets changed >> without the other(s)), > > This argument is bogus. We will never ever change a user-visible command > line option. Ever. > >> but also eliminates a warning some gcc versions emit ("array access >> beyond array bounds", observed with 4.3.4) in the 32-bit case. > > Now that I'm interested in - how exactly do you trigger this? gcc > version, etc? As said - 4.3.4 (I only now realize that this could also have been a kernel version). >> --- 4.4-rc6/arch/x86/kernel/cpu/microcode/core.c >> +++ 4.4-rc6-x86-ucode-early-string/arch/x86/kernel/cpu/microcode/core.c >> @@ -83,13 +83,11 @@ static bool __init check_loader_disabled >> { >> #ifdef CONFIG_X86_32 >> const char *cmdline = (const char *)__pa_nodebug(boot_command_line); >> - const char *opt = "dis_ucode_ldr"; >> - const char *option = (const char *)__pa_nodebug(opt); >> + const char *option = (const char *)__pa_nodebug(__setup_str_disable_loader); >> bool *res = (bool *)__pa_nodebug(&dis_ucode_ldr); >> - >> #else /* CONFIG_X86_64 */ >> const char *cmdline = boot_command_line; >> - const char *option = "dis_ucode_ldr"; >> + const char *option = __setup_str_disable_loader; >> bool *res = &dis_ucode_ldr; >> #endif > > I don't like it: it is not clear at a glance that this __setup_str* > magic gets generated from the __setup macro. In addition, this code is > as unreadable as it is now - your patch makes it even more cryptic. > > I much prefer the redundancy. And the compiler warning? At the very least these should then be const char __initconst []. Jan