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From: Dan Carpenter <dan.carpenter@oracle.com>
To: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
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
Subject: Re: [PATCH] bnx2fc: shift wrapping bug in bnx2fc_process_unsol_compl()
Date: Mon, 28 Nov 2016 13:24:45 +0000	[thread overview]
Message-ID: <20161128132137.GR6266@mwanda> (raw)
In-Reply-To: <20161126183629.9969-1-christophe.jaillet@wanadoo.fr>

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 <christophe.jaillet@wanadoo.fr>
> ---
> 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


WARNING: multiple messages have this Message-ID (diff)
From: Dan Carpenter <dan.carpenter@oracle.com>
To: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
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
Subject: Re: [PATCH] bnx2fc: shift wrapping bug in bnx2fc_process_unsol_compl()
Date: Mon, 28 Nov 2016 16:24:45 +0300	[thread overview]
Message-ID: <20161128132137.GR6266@mwanda> (raw)
In-Reply-To: <20161126183629.9969-1-christophe.jaillet@wanadoo.fr>

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 <christophe.jaillet@wanadoo.fr>
> ---
> 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


  reply	other threads:[~2016-11-28 13:24 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-11-26 18:36 [PATCH] bnx2fc: shift wrapping bug in bnx2fc_process_unsol_compl() Christophe JAILLET
2016-11-26 18:36 ` Christophe JAILLET
2016-11-28 13:24 ` Dan Carpenter [this message]
2016-11-28 13:24   ` Dan Carpenter
2016-11-28 17:05 ` Laurence Oberman
2016-11-28 17:05   ` Laurence Oberman

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