From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dan Carpenter Date: Mon, 28 Nov 2016 13:24:45 +0000 Subject: Re: [PATCH] bnx2fc: shift wrapping bug in bnx2fc_process_unsol_compl() Message-Id: <20161128132137.GR6266@mwanda> List-Id: References: <20161126183629.9969-1-christophe.jaillet@wanadoo.fr> In-Reply-To: <20161126183629.9969-1-christophe.jaillet@wanadoo.fr> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Christophe JAILLET Cc: QLogic-Storage-Upstream@qlogic.com, jejb@linux.vnet.ibm.com, martin.petersen@oracle.com, linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org On Sat, Nov 26, 2016 at 07:36:29PM +0100, Christophe JAILLET wrote: > BNX2FC_NUM_ERR_BITS is 63. err_warn_bit_map is a u64. So, to make sure that > no shift wrapping will occur, we need need additionnal casting. > > The same test is already done a few lines above and '(u64)1' is already > used there. So just do the same here. > > Signed-off-by: Christophe JAILLET > --- > I guess that this could also be written with a '1ULL << i' which would be > cleaner and less verbose IMHO, but apparently this driver does not use > such things yet. So keep the current style with casting. Ugh... No. This is not code to emulate. Use 1ULL << i. Even if we did the cast, you would only need one: if (err_warn_bit_map & ((u64)1 << i)) { regards, dan carpenter