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From: Markus Elfring <Markus.Elfring@web.de>
To: James Bottomley <jejb@linux.ibm.com>,
	linux-scsi@vger.kernel.org, kernel-janitors@vger.kernel.org,
	"Martin K. Petersen" <martin.petersen@oracle.com>
Cc: LKML <linux-kernel@vger.kernel.org>
Subject: Re: scsi: ses: Move a label in ses_enclosure_data_process()
Date: Sat, 30 Dec 2023 08:04:32 +0100	[thread overview]
Message-ID: <b65afa15-41e6-4d71-87bd-39fd688fa551@web.de> (raw)
In-Reply-To: <9d24844f30604f969ac10da456801f594ce72f2d.camel@linux.ibm.com>

>> 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

Such “a nop” can trigger the allocation of extra data processing resources,
can't it?


> is so we don't have to special case the free path.

A bit more development attention can hopefully connect the mentioned label
with a more appropriate jump target directly.


>                                                     The reason we do
> that is because multiple special case paths through code leads to more
> complex control flows and more potential bugs.

You probably know some advices from another information source.

https://wiki.sei.cmu.edu/confluence/display/c/MEM12-C.+Consider+using+a+goto+chain+when+leaving+a+function+on+error+when+using+and+releasing+resources


>                                                 If coccinelle suddenly
> thinks this is a problem, it's coccinelle that needs fixing.

This software tool can help to point source code places out for further considerations.
The search patterns are evolving accordingly.

Regards,
Markus

  parent reply	other threads:[~2023-12-30  7:04 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-12-28 14:48 [PATCH] scsi: ses: Move a label in ses_enclosure_data_process() Markus Elfring
2023-12-29 17:21 ` James Bottomley
2023-12-29 17:29   ` Julia Lawall
2023-12-30  7:04   ` Markus Elfring [this message]
2023-12-30 12:41     ` James Bottomley
2023-12-30 13:36       ` Markus Elfring
2023-12-30 13:45         ` James Bottomley
2023-12-30 14:25           ` Markus Elfring
2023-12-31 14:07             ` James Bottomley

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