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From: Dan Carpenter <dan.carpenter@oracle.com>
To: kernel-janitors@vger.kernel.org
Subject: Re: [patch] nvme-fabrics: correct some printk information
Date: Sat, 10 Dec 2016 18:55:29 +0000	[thread overview]
Message-ID: <20161210184029.GY8176@mwanda> (raw)
In-Reply-To: <1481369270.5946.51.camel@perches.com>

On Sat, Dec 10, 2016 at 03:27:50AM -0800, Joe Perches wrote:
> On Sat, 2016-12-10 at 12:06 +0300, Dan Carpenter wrote:
> > We really don't care where "ctrl" is on the stack since we're just
> > returning soon what we want is the actual ctrl pointer itself.
> > 
> > Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
> > 
> > diff --git a/drivers/nvme/host/fc.c b/drivers/nvme/host/fc.c
> []
> > @@ -2402,7 +2402,7 @@ enum blk_eh_timer_return
> >  
> >  	dev_info(ctrl->ctrl.device,
> >  		"NVME-FC{%d}: new ctrl: NQN \"%s\" (%p)\n",
> > -		ctrl->cnum, ctrl->ctrl.opts->subsysnqn, &ctrl);
> > +		ctrl->cnum, ctrl->ctrl.opts->subsysnqn, ctrl);
> 
> Found by script or inspection?
> 
> If by script, it seems unlikely there's only 1 instance
> where an address of an automatic pointer type is used
> incorrectly.

Script.  But it's using a pretty specific heuristic where we kmalloc a
pointer and then pass the address.  It prints few warnings.  Probably
40% false positives, but the remaining examples of course are 100% false
positives.

regards,
dan carpenter


WARNING: multiple messages have this Message-ID (diff)
From: dan.carpenter@oracle.com (Dan Carpenter)
Subject: [patch] nvme-fabrics: correct some printk information
Date: Sat, 10 Dec 2016 21:55:29 +0300	[thread overview]
Message-ID: <20161210184029.GY8176@mwanda> (raw)
In-Reply-To: <1481369270.5946.51.camel@perches.com>

On Sat, Dec 10, 2016@03:27:50AM -0800, Joe Perches wrote:
> On Sat, 2016-12-10@12:06 +0300, Dan Carpenter wrote:
> > We really don't care where "ctrl" is on the stack since we're just
> > returning soon what we want is the actual ctrl pointer itself.
> > 
> > Signed-off-by: Dan Carpenter <dan.carpenter at oracle.com>
> > 
> > diff --git a/drivers/nvme/host/fc.c b/drivers/nvme/host/fc.c
> []
> > @@ -2402,7 +2402,7 @@ enum blk_eh_timer_return
> >  
> >  	dev_info(ctrl->ctrl.device,
> >  		"NVME-FC{%d}: new ctrl: NQN \"%s\" (%p)\n",
> > -		ctrl->cnum, ctrl->ctrl.opts->subsysnqn, &ctrl);
> > +		ctrl->cnum, ctrl->ctrl.opts->subsysnqn, ctrl);
> 
> Found by script or inspection?
> 
> If by script, it seems unlikely there's only 1 instance
> where an address of an automatic pointer type is used
> incorrectly.

Script.  But it's using a pretty specific heuristic where we kmalloc a
pointer and then pass the address.  It prints few warnings.  Probably
40% false positives, but the remaining examples of course are 100% false
positives.

regards,
dan carpenter

WARNING: multiple messages have this Message-ID (diff)
From: Dan Carpenter <dan.carpenter@oracle.com>
To: Joe Perches <joe@perches.com>
Cc: James Smart <james.smart@broadcom.com>,
	Keith Busch <keith.busch@intel.com>, Jens Axboe <axboe@fb.com>,
	linux-nvme@lists.infradead.org, linux-kernel@vger.kernel.org,
	kernel-janitors@vger.kernel.org
Subject: Re: [patch] nvme-fabrics: correct some printk information
Date: Sat, 10 Dec 2016 21:55:29 +0300	[thread overview]
Message-ID: <20161210184029.GY8176@mwanda> (raw)
In-Reply-To: <1481369270.5946.51.camel@perches.com>

On Sat, Dec 10, 2016 at 03:27:50AM -0800, Joe Perches wrote:
> On Sat, 2016-12-10 at 12:06 +0300, Dan Carpenter wrote:
> > We really don't care where "ctrl" is on the stack since we're just
> > returning soon what we want is the actual ctrl pointer itself.
> > 
> > Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
> > 
> > diff --git a/drivers/nvme/host/fc.c b/drivers/nvme/host/fc.c
> []
> > @@ -2402,7 +2402,7 @@ enum blk_eh_timer_return
> >  
> >  	dev_info(ctrl->ctrl.device,
> >  		"NVME-FC{%d}: new ctrl: NQN \"%s\" (%p)\n",
> > -		ctrl->cnum, ctrl->ctrl.opts->subsysnqn, &ctrl);
> > +		ctrl->cnum, ctrl->ctrl.opts->subsysnqn, ctrl);
> 
> Found by script or inspection?
> 
> If by script, it seems unlikely there's only 1 instance
> where an address of an automatic pointer type is used
> incorrectly.

Script.  But it's using a pretty specific heuristic where we kmalloc a
pointer and then pass the address.  It prints few warnings.  Probably
40% false positives, but the remaining examples of course are 100% false
positives.

regards,
dan carpenter

  reply	other threads:[~2016-12-10 18:55 UTC|newest]

Thread overview: 48+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-12-10  9:06 [patch] nvme-fabrics: correct some printk information Dan Carpenter
2016-12-10  9:06 ` Dan Carpenter
2016-12-10  9:06 ` Dan Carpenter
2016-12-10 11:27 ` Joe Perches
2016-12-10 11:27   ` Joe Perches
2016-12-10 11:27   ` Joe Perches
2016-12-10 18:55   ` Dan Carpenter [this message]
2016-12-10 18:55     ` Dan Carpenter
2016-12-10 18:55     ` Dan Carpenter
2016-12-10 20:06     ` Julia Lawall
2016-12-10 20:06       ` Julia Lawall
2016-12-10 20:06       ` Julia Lawall
2016-12-10 20:24       ` Dan Carpenter
2016-12-10 20:24         ` Dan Carpenter
2016-12-10 20:24         ` Dan Carpenter
2016-12-10 20:54       ` Joe Perches
2016-12-10 20:54         ` Joe Perches
2016-12-10 20:54         ` Joe Perches
2016-12-10 21:07         ` Dan Carpenter
2016-12-10 21:07           ` Dan Carpenter
2016-12-10 21:07           ` Dan Carpenter
2016-12-10 22:24           ` Joe Perches
2016-12-10 22:24             ` Joe Perches
2016-12-10 22:24             ` Joe Perches
2016-12-12  9:33             ` Dan Carpenter
2016-12-12  9:33               ` Dan Carpenter
2016-12-12  9:33               ` Dan Carpenter
2016-12-12 15:47               ` Julia Lawall
2016-12-12 15:47                 ` Julia Lawall
2016-12-12 15:47                 ` Julia Lawall
2016-12-12 15:55                 ` Joe Perches
2016-12-12 15:55                   ` Joe Perches
2016-12-12 15:55                   ` Joe Perches
2016-12-10 22:07         ` Julia Lawall
2016-12-10 22:07           ` Julia Lawall
2016-12-10 22:07           ` Julia Lawall
2016-12-10 22:27           ` Joe Perches
2016-12-10 22:27             ` Joe Perches
2016-12-10 22:27             ` Joe Perches
2016-12-11  0:36       ` Joe Perches
2016-12-11  0:36         ` Joe Perches
2016-12-11  0:36         ` Joe Perches
2016-12-20  0:40 ` James Smart
2016-12-20  0:40   ` James Smart
2016-12-20  0:40   ` James Smart
2016-12-20  9:16   ` Dan Carpenter
2016-12-20  9:16     ` Dan Carpenter
2016-12-20  9:16     ` Dan Carpenter

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