From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D64A5CCA47D for ; Fri, 10 Jun 2022 05:20:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1345985AbiFJFUl (ORCPT ); Fri, 10 Jun 2022 01:20:41 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36338 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1346132AbiFJFUk (ORCPT ); Fri, 10 Jun 2022 01:20:40 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 83A643B3C2; Thu, 9 Jun 2022 22:20:36 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 43230B830F6; Fri, 10 Jun 2022 05:20:35 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6278AC34114; Fri, 10 Jun 2022 05:20:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1654838433; bh=obJOg0nC5+NFcMbSl//FLvr+ceUwgMoc50Ko3u2Lf80=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=k/PjXRW3Ejm3OWA0ILi7O80zfEKst1OpP7BC0SxRltN5BaZsp6jjKtr3wXBUDO5zB e4Raz/E5WEJs1UM/fE5IzTFZTwR5xBef7mdwfpGnTFs6jcYygdrsalBjswLqjAwcn8 xxzJxOn25O10o5RwvKHTCaY9QGZ0KZC/wv3VRoMA= Date: Fri, 10 Jun 2022 07:20:31 +0200 From: Greg Kroah-Hartman To: Bill Wendling Cc: Jan Engelhardt , Andrew Morton , Bill Wendling , Tony Luck , Borislav Petkov , Thomas Gleixner , Ingo Molnar , Dave Hansen , "maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)" , "H. Peter Anvin" , Phillip Potter , Arnd Bergmann , "Rafael J. Wysocki" , Jan Kara , Pablo Neira Ayuso , Jozsef Kadlecsik , Florian Westphal , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Jaroslav Kysela , Takashi Iwai , Nathan Chancellor , Nick Desaulniers , Tom Rix , Ross Philipson , Daniel Kiper , linux-edac@vger.kernel.org, LKML , ACPI Devel Maling List , linux-mm@kvack.org, netfilter-devel@vger.kernel.org, coreteam@netfilter.org, Networking , alsa-devel@alsa-project.org, clang-built-linux Subject: Re: [PATCH 00/12] Clang -Wformat warning fixes Message-ID: References: <20220609221702.347522-1-morbo@google.com> <20220609152527.4ad7862d4126e276e6f76315@linux-foundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: netfilter-devel@vger.kernel.org On Thu, Jun 09, 2022 at 04:16:16PM -0700, Bill Wendling wrote: > On Thu, Jun 9, 2022 at 4:03 PM Jan Engelhardt wrote: > > On Friday 2022-06-10 00:49, Bill Wendling wrote: > > >On Thu, Jun 9, 2022 at 3:25 PM Andrew Morton wrote: > > >> On Thu, 9 Jun 2022 22:16:19 +0000 Bill Wendling wrote: > > >> > > >> > This patch set fixes some clang warnings when -Wformat is enabled. > > >> > > >> tldr: > > >> > > >> - printk(msg); > > >> + printk("%s", msg); > > >> > > >> Otherwise these changes are a > > >> useless consumer of runtime resources. > > > > > >Calling a "printf" style function is already insanely expensive. > > >[...] > > >The "printk" and similar functions all have the "__printf" attribute. > > >I don't know of a modification to that attribute which can turn off > > >this type of check. > > > > Perhaps you can split vprintk_store in the middle (after the call to > > vsnprintf), and offer the second half as a function of its own (e.g. > > "puts"). Then the tldr could be > > > > - printk(msg); > > + puts(msg); > > That might be a nice compromise. Andrew, what do you think? You would need to do that for all of the dev_printk() variants, so I doubt that would ever be all that useful as almost no one should be using a "raw" printk() these days. thanks, greg k-h