linux-kernel - Re: leds: trigger: oneshot: One function call less in pattern

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Date: Thu, 11 Jan 2024 13:05:13 +0000
From: Lee Jones <lee@...nel.org>
To: Markus Elfring <Markus.Elfring@....de>
Cc: linux-leds@...r.kernel.org, kernel-janitors@...r.kernel.org,
	Pavel Machek <pavel@....cz>, LKML <linux-kernel@...r.kernel.org>,
	cocci@...ia.fr
Subject: Re: leds: trigger: oneshot: One function call less in pattern_init()
 after error detection

On Thu, 11 Jan 2024, Markus Elfring wrote:

> >> The kfree() function was called in one case by
> >> the pattern_init() function during error handling
> >> even if the passed variable contained a null pointer.
> >
> > It's totally valid to call kfree() on a NULL pointer:
> >
> >   * If @object is NULL, no operation is performed.
> >
> > Why do we care all that much?
> 
> Would you dare to categorise such special function calls as redundant?
> 
> Should they be skipped in more cases?
> 
> See also:
> 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

I have no idea what you're trying to say.

The premise of your patch is based on the fact that we shouldn't call
kfree() with a NULL pointer.  When in actual fact kfree() is more than
capable of handling cases where the passed object is NULL, and goes as
far as to document as such.  Meaning that unless I'm convinced
otherwise, patches like this remain in the category of churn.

-- 
Lee Jones [李琼斯]