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Date: Fri, 29 Dec 2023 18:29:02 +0100 (CET)
From: Julia Lawall <julia.lawall@inria.fr>
To: James Bottomley <jejb@linux.ibm.com>
cc: Markus Elfring <Markus.Elfring@web.de>, linux-scsi@vger.kernel.org, 
    kernel-janitors@vger.kernel.org, 
    "Martin K. Petersen" <martin.petersen@oracle.com>, 
    LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] scsi: ses: Move a label in
 ses_enclosure_data_process()
In-Reply-To: <9d24844f30604f969ac10da456801f594ce72f2d.camel@linux.ibm.com>
Message-ID: <50978c86-cf4a-991d-54ab-50d8d977f946@inria.fr>
References: <4616e325-e313-4078-9788-dd1e6e51b9e0@web.de> <9d24844f30604f969ac10da456801f594ce72f2d.camel@linux.ibm.com>
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On Fri, 29 Dec 2023, James Bottomley wrote:

> On Thu, 2023-12-28 at 15:48 +0100, Markus Elfring wrote:
> > From: Markus Elfring <elfring@users.sourceforge.net>
> > Date: Thu, 28 Dec 2023 15:38:09 +0100
> >
> > The kfree() function was called in up to three cases by
> > the ses_enclosure_data_process() function during error handling
> > even if the passed variable contained a null pointer.
> > This issue was detected by using the Coccinelle software.
>
> Why is this an issue?  The whole point of having kfree(NULL) be a nop
> is so we don't have to special case the free path.  The reason we do
> that is because multiple special case paths through code leads to more
> complex control flows and more potential bugs.  If coccinelle suddenly
> thinks this is a problem, it's coccinelle that needs fixing.

Coccinelle doesn't think anything.  Markus for some reason thinks it's a
problem and uses Coccinelle to find occurrences of it.

julia