From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pj1-f51.google.com (mail-pj1-f51.google.com [209.85.216.51]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4DE986D19 for ; Wed, 17 Aug 2022 19:39:50 +0000 (UTC) Received: by mail-pj1-f51.google.com with SMTP id o5-20020a17090a3d4500b001ef76490983so2892931pjf.2 for ; Wed, 17 Aug 2022 12:39:50 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc; bh=r68vuNb5uh5ONaquxzxTqZ7ONll565ksnKh3ylI2Qso=; b=fMHE08mTNGtgJz5Oy07EEtIpqqdqolGc17nEd8gVvKUw5CdSjv/rRzxqaLb78IHB67 dldRsPtd4wwFvOhdDwQV4bqau/Eu1sfiQ9hhO6/lGkKw/IpZWigxnU2oPUBD+pZqQKEO 7bul/7sfTougSEqU7vjXZAS4IeQZPRusWPFiU= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc; bh=r68vuNb5uh5ONaquxzxTqZ7ONll565ksnKh3ylI2Qso=; b=yJnhDcdGgwP4wMV8iyHHwN2fYiZ7L85ZbAio3T0Zz6wNZW2BIxThPXm3Bz8tWzmRKB bCI1O67ecvHxqw0XBKYj0DYxft+9oWzNqU/mbd+qTxY1fsDGzV39xBjrkudzmmf1W02q ixwk14SxWt2nVx/NmYBbVn8Gm8YX61LzpmLMamam1VVw1W2xIJjrJtIYB03J5PdaCp2S bvDHZ4KV6lcqNPoHBeNUkbejGXsLz8f1QIga0U3WrumGDn/T72DHdXJojx6MVprzzImp JJYKiGicWHqSm2X9jMfS4nj7wK3UFd2hw5sIhDpHksJiNySXB40LUg0jPAYvbuVUf3Cl 9FXQ== X-Gm-Message-State: ACgBeo0abc1LCQI3bZx/AfVO9IacxD8XIdsClP7VNkTbaiQXixij/yct g3yjT+bc0VWIkimNnoZcUNuuHw== X-Google-Smtp-Source: AA6agR4QLUE1Ptr9L6/5prtoBq9XWGwAqLKFX6+0rTRLhg6Qq0It1iuQEECu3eQaVfLVc7g9ixBe/A== X-Received: by 2002:a17:902:ccd1:b0:172:5c49:34be with SMTP id z17-20020a170902ccd100b001725c4934bemr21344292ple.23.1660765189710; Wed, 17 Aug 2022 12:39:49 -0700 (PDT) Received: from www.outflux.net (smtp.outflux.net. [198.145.64.163]) by smtp.gmail.com with ESMTPSA id q7-20020aa79607000000b0052d0a93f6d5sm10845922pfg.116.2022.08.17.12.39.48 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 17 Aug 2022 12:39:49 -0700 (PDT) Date: Wed, 17 Aug 2022 12:39:48 -0700 From: Kees Cook To: Miguel Ojeda Cc: Linus Torvalds , Greg Kroah-Hartman , rust-for-linux@vger.kernel.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, patches@lists.linux.dev, Jarkko Sakkinen , Boqun Feng Subject: Re: [PATCH v9 03/27] kallsyms: add static relationship between `KSYM_NAME_LEN{,_BUFFER}` Message-ID: <202208171238.80053F8C@keescook> References: <20220805154231.31257-1-ojeda@kernel.org> <20220805154231.31257-4-ojeda@kernel.org> Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220805154231.31257-4-ojeda@kernel.org> On Fri, Aug 05, 2022 at 05:41:48PM +0200, Miguel Ojeda wrote: > This adds a static assert to ensure `KSYM_NAME_LEN_BUFFER` > gets updated when `KSYM_NAME_LEN` changes. > > The relationship used is one that keeps the new size (512+1) > close to the original buffer size (500). > > Co-developed-by: Boqun Feng > Signed-off-by: Boqun Feng > Signed-off-by: Miguel Ojeda > --- > scripts/kallsyms.c | 6 +++++- > 1 file changed, 5 insertions(+), 1 deletion(-) > > diff --git a/scripts/kallsyms.c b/scripts/kallsyms.c > index f3c5a2623f71..f543b1c4f99f 100644 > --- a/scripts/kallsyms.c > +++ b/scripts/kallsyms.c > @@ -33,7 +33,11 @@ > #define KSYM_NAME_LEN 128 > > /* A substantially bigger size than the current maximum. */ > -#define KSYM_NAME_LEN_BUFFER 499 > +#define KSYM_NAME_LEN_BUFFER 512 > +_Static_assert( > + KSYM_NAME_LEN_BUFFER == KSYM_NAME_LEN * 4, > + "Please keep KSYM_NAME_LEN_BUFFER in sync with KSYM_NAME_LEN" > +); Why not just make this define: #define KSYM_NAME_LEN_BUFFER (KSYM_NAME_LEN * 4) ? If there's a good reason not it, please put it in the commit log. -Kees -- Kees Cook