Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1765106AbXHLB6T (ORCPT ); Sat, 11 Aug 2007 21:58:19 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1758018AbXHLB6B (ORCPT ); Sat, 11 Aug 2007 21:58:01 -0400 Received: from smtpq1.tilbu1.nb.home.nl ([213.51.146.200]:42255 "EHLO smtpq1.tilbu1.nb.home.nl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757065AbXHLB6A (ORCPT ); Sat, 11 Aug 2007 21:58:00 -0400 Message-ID: <46BE6854.90502@gmail.com> Date: Sun, 12 Aug 2007 03:54:28 +0200 From: Rene Herman User-Agent: Thunderbird 2.0.0.6 (X11/20070728) MIME-Version: 1.0 To: Jesper Juhl CC: linux-scsi@vger.kernel.org, Linux Kernel Mailing List , Mike Miller , iss_storagedev@hp.com Subject: Re: [PATCH] Re: cciss: warning: right shift count >= width of type References: <200708120228.26234.jesper.juhl@gmail.com> <9a8748490708111756o63ddaeedja091fb2f0b4dbc40@mail.gmail.com> <46BE617D.6010505@gmail.com> In-Reply-To: <46BE617D.6010505@gmail.com> Content-Type: text/plain; charset=ISO-8859-15; format=flowed Content-Transfer-Encoding: 7bit X-AtHome-MailScanner-Information: Please contact support@home.nl for more information X-AtHome-MailScanner: Found to be clean Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2581 Lines: 79 On 08/12/2007 03:25 AM, Rene Herman wrote: > On 08/12/2007 02:56 AM, Jesper Juhl wrote: > >> (whoops, forgot to add maintainer to Cc - now added) > > Ehm... too late... Useless followup though -- hp.com rejects me as it feels the SPF neutral results gmail sends due to me not using the gmail SMTP server and/or web interface is something it wants to listen to. I see you are @gmail as well, which depending on how you use it might mean your are also not able to reach @hp. If anyone can get HP to fix their mail setup, that'd be useful. Rene. > >> On 12/08/07, Jesper Juhl wrote: >>> Hi, >>> >>> I've been building some randconfig kernels lately and I've noticed >>> this in a few builds : >>> >>> drivers/block/cciss.c:2614: warning: right shift count >= width of type >>> drivers/block/cciss.c:2615: warning: right shift count >= width of type >>> drivers/block/cciss.c:2616: warning: right shift count >= width of type >>> >>> The code in question is this : >>> >>> static void do_cciss_request(struct request_queue *q) >>> { >>> ... >>> sector_t start_blk; >>> ... >>> c->Request.CDB[2]= (start_blk >> 56) & >>> 0xff; //MSB >>> c->Request.CDB[3]= (start_blk >> 48) & 0xff; >>> c->Request.CDB[4]= (start_blk >> 40) & 0xff; >>> ... >>> } >>> >>> >>> The problem stems from these lines in include/linux/types.h : >>> ... >>> #ifdef CONFIG_LBD >>> typedef u64 sector_t; >>> #else >>> typedef unsigned long sector_t; >>> #endif >>> ... >>> >>> So on a 32bit arch without CONFIG_LBD, sector_t is going to be 32 >>> bits wide. >>> Thus it seems gcc is absolutely right in complaining about those >>> 56, 48 & 40 bit shifts, since they are indeed wider than the type >>> in the "!CONFIG_LBD on a 32bit arch" case. >>> >>> >>> I must admit that I have no idear what the proper way to deal with >>> that is, so I'll just report it so hopefully someone else can fix it. >>> >>> By the way; I'm building current Linus git tree, head at commit >>> ac07860264bd2b18834d3fa3be47032115524cea > > Well, given that it's explicitly treating start_blk as a 64-bit value, > the proper fix is probably to cast start_blk to an actual (guaranteed) > 64-bit value. Untested, uncompiled, and someone else may disagree: > > Rene. > - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/