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 B1645C63705 for ; Wed, 7 Dec 2022 12:21:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229580AbiLGMVS (ORCPT ); Wed, 7 Dec 2022 07:21:18 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43262 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229593AbiLGMVO (ORCPT ); Wed, 7 Dec 2022 07:21:14 -0500 Received: from mail-wr1-x42a.google.com (mail-wr1-x42a.google.com [IPv6:2a00:1450:4864:20::42a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C94A54C265; Wed, 7 Dec 2022 04:21:09 -0800 (PST) Received: by mail-wr1-x42a.google.com with SMTP id u12so26875675wrr.11; Wed, 07 Dec 2022 04:21:09 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; 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=CUj61DdS53bau6yW/e52WrW7NaFKUXNHm1+hhxD6do4=; b=ncNhFYLh1vam6J0Brgif4hTvH5bRVaW4TcnkFLTIE2giOPlvKB6HH7gNxnYl5O+dB/ gl5skH8DaAw8O5J/wQ0nVHRx4u48Cp6qPzpTlX2AmYBJjabhQOVZqz8WSNK5n/reoiFq 27q01qXXc1tcLu8LIiv7dLYy/etczVlpO1+sVNQD4NHe5d+5h2yFsT1wngNDDAaq+Sem jAmjAYmmBbEHrr4UlBG8hVhVhOAIuCH+MzkP3UdAgZi0nBuBLFBDep7ns5QRxyUFofWU ZnlWYb7Mw1YAn5TXJ4H/hy1wzTOIrJmRZFt8RUvaQPIfIU8MhH+6wLjbnZV1DkvQc89p ub0w== 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:subject:date :message-id:reply-to; bh=CUj61DdS53bau6yW/e52WrW7NaFKUXNHm1+hhxD6do4=; b=7jqXFbsjTmVwW/5PLRIYAGTK7y72cAI7pr4deoM9wO8sOiTyS6APUOFHBXp/kD84p/ Ncv6Fzw0y8NyXRExeTG28KM/ibLlU3ch1DZ7YV33x1Pmd0cMywiim8sbqRMi1RjY+vYd EoDpBllwWKznN+GqwQ0DoiyGD6kAbsTBuYrBXuOaWlV6AAmddBqz2iNpA/2sPAXPRoIh cR/W/xUB7Cw3oMR6AxI22jKJnhi0yyR00Mm8R43W3tVJfwKVYlf1FEKcbt0ieIuPbx3U BNzuEgKKylAGZJx2A+jVoQdRt87bZhnIee6G7S+MrgSxzMO6SGOJo7nsgieuUcOrrKFf LHWQ== X-Gm-Message-State: ANoB5plK1x/r+gR0LjKVBop8ZD1sQQT+zPCszxGJqipEEOJCsjvAN0yY xPwEE9CdGPgrN/QYDWYIjv8= X-Google-Smtp-Source: AA0mqf7f0B+1FCT7D6yFWKPF49aQa2dE932U4W/aRJuaHZLSIxaR0hJuxOiIXpPPlYw3XxolkpOfhw== X-Received: by 2002:a5d:4107:0:b0:242:48c3:7746 with SMTP id l7-20020a5d4107000000b0024248c37746mr13007843wrp.457.1670415668252; Wed, 07 Dec 2022 04:21:08 -0800 (PST) Received: from localhost ([102.36.222.112]) by smtp.gmail.com with ESMTPSA id r2-20020a056000014200b002422bc69111sm24045366wrx.9.2022.12.07.04.21.07 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 07 Dec 2022 04:21:07 -0800 (PST) Date: Wed, 7 Dec 2022 15:21:04 +0300 From: Dan Carpenter To: Vladimir Oltean Cc: "David S. Miller" , netdev@vger.kernel.org, kernel-janitors@vger.kernel.org Subject: Re: [PATCH net] lib: packing: fix shift wrapping in bit_reverse() Message-ID: References: <20221207121936.bajyi5igz2kum4v3@skbuf> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20221207121936.bajyi5igz2kum4v3@skbuf> Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Wed, Dec 07, 2022 at 02:19:36PM +0200, Vladimir Oltean wrote: > On Wed, Dec 07, 2022 at 02:23:28PM +0300, Dan Carpenter wrote: > > The bit_reverse() function is clearly supposed to be able to handle > > 64 bit values, but the types for "(1 << i)" and "bit << (width - i - 1)" > > are not enough to handle more than 32 bits. > > > > Fixes: 554aae35007e ("lib: Add support for generic packing operations") > > Signed-off-by: Dan Carpenter > > --- > > lib/packing.c | 5 ++--- > > 1 file changed, 2 insertions(+), 3 deletions(-) > > > > diff --git a/lib/packing.c b/lib/packing.c > > index 9a72f4bbf0e2..9d7418052f5a 100644 > > --- a/lib/packing.c > > +++ b/lib/packing.c > > @@ -32,12 +32,11 @@ static int get_reverse_lsw32_offset(int offset, size_t len) > > static u64 bit_reverse(u64 val, unsigned int width) > > { > > u64 new_val = 0; > > - unsigned int bit; > > unsigned int i; > > > > for (i = 0; i < width; i++) { > > - bit = (val & (1 << i)) != 0; > > - new_val |= (bit << (width - i - 1)); > > + if (val & BIT_ULL(1)) > > hmm, why 1 and not i? Because I'm a moron. Let me resend. regards, dan carpenter