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 64130C761A6 for ; Mon, 3 Apr 2023 15:35:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232878AbjDCPfJ (ORCPT ); Mon, 3 Apr 2023 11:35:09 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40308 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232858AbjDCPfH (ORCPT ); Mon, 3 Apr 2023 11:35:07 -0400 Received: from mail-pl1-x629.google.com (mail-pl1-x629.google.com [IPv6:2607:f8b0:4864:20::629]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E379B1BE1 for ; Mon, 3 Apr 2023 08:35:05 -0700 (PDT) Received: by mail-pl1-x629.google.com with SMTP id c18so28378416ple.11 for ; Mon, 03 Apr 2023 08:35:05 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; t=1680536105; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=fR2s9+JDNNa1uEdAtZHMM34i2EJ2xvvS10PJPUpk8Tw=; b=JeEDSZDdrhUuzUy391WQWKkkvpcdSBaOtDd6sAfXdgcQ0si3zVaG88tzCJbsDWfpqE /oiggCHPIWfK8U+lMtNOrAqJQgCDxFhVmkKjISMu9m3FeCArnhwiN58oCX0cd5ihNmVB dt5+py3or0hapeKq3ptfUgORdG6Ym8ZNkZbmU= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1680536105; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=fR2s9+JDNNa1uEdAtZHMM34i2EJ2xvvS10PJPUpk8Tw=; b=sLacMPr/1Avi9JEtmpBmw13VGniyonCqcqqddeZhx/oPqkOOWswwC921ZzS1FkFyGF rksZMSsDDU+EJMcrFxglZnurKINj55QaVvvInpu+2PVxalw//vi+9l6s3SuYSx48nT9V ddIMbosKAZjYzcuY6DJjJEFDXFI3bE9JyWTBezONNSWC3DuKJUmoyRBpickBUSRejNl9 r/ogYWIu2wHHZFko3vSqFUWVorWM7jLxQiASzvVRvpdjhyhK4gvsR+QgZGESO9WMRJ2n kzg8c3UFHzx95Q8WK4/nssxhArnfhazvD8Iq9LF6tJeNWAoZVmSHz3+QzbszYK1k8nLx Py2A== X-Gm-Message-State: AAQBX9dwnvDjN9vZ9RevGNb/l+icncermgxT12NdTYwlYE2JG1HnHTc3 PWB7tf9L5mYyP+AHVa/UehOMBw== X-Google-Smtp-Source: AKy350bwl32I78BgAl9N4MzmN3dvEOxV4sQ+JOgKQSF9qprd8wneNSZznscrcTCeXOmUCL/RBqng+g== X-Received: by 2002:a17:902:e847:b0:19e:d6f2:feea with SMTP id t7-20020a170902e84700b0019ed6f2feeamr46232340plg.9.1680536105355; Mon, 03 Apr 2023 08:35:05 -0700 (PDT) Received: from google.com (KD124209188001.ppp-bb.dion.ne.jp. [124.209.188.1]) by smtp.gmail.com with ESMTPSA id t12-20020a170902bc4c00b001a1d4a985eesm6698057plz.228.2023.04.03.08.35.00 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 03 Apr 2023 08:35:03 -0700 (PDT) Date: Tue, 4 Apr 2023 00:34:58 +0900 From: Sergey Senozhatsky To: Jaewon Kim Cc: Petr Mladek , Jaewon Kim , "senozhatsky@chromium.org" , "linux-mm@kvack.org" , "linux-kernel@vger.kernel.org" , GyeongHwan Hong Subject: Re: [RFC] vsprintf: compile error on %09pK Message-ID: <20230403153458.GE12892@google.com> References: <20230403104617epcms1p383bacbca705c0d7e4fffca6833050e42@epcms1p3> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On (23/04/03 23:39), Jaewon Kim wrote: [..] > > Okay, then we can't use %09pK. I've just wondered because %9pK works. This is not per printk / kernel, Wformat warnings come from the compiler. Per C11 (7.21.6 6): 0 For d, i, o, u, x, X, a, A, e, E, f, F, g, and G conversions, leading zeros (following any indication of sign or base) are used to pad to the field width rather than performing space padding ... For other conversions, the behavior is undefined. So using 0 for p should trigger an undefined behavior as far as the standard C concerned. Unless I'm missing something.