From: Pavel Machek <pavel@ucw.cz>
To: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>,
Christophe JAILLET <christophe.jaillet@wanadoo.fr>,
dmurphy@ti.com, jacek.anaszewski@gmail.com,
linux-leds@vger.kernel.org, linux-kernel@vger.kernel.org,
kernel-janitors@vger.kernel.org
Subject: Re: [PATCH] leds: lp50xx: Fix an error handling path in 'lp50xx_probe_dt()'
Date: Wed, 25 Nov 2020 11:46:29 +0100 [thread overview]
Message-ID: <20201125104629.GE25562@amd> (raw)
In-Reply-To: <20200928115301.GB3987353@kuha.fi.intel.com>
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Hi!
> > > > I have been trying to teach Smatch to understand reference counting so
> > > > it can discover these kinds of bugs automatically.
> > > >
> > > > I don't know how software_node_get_next_child() can work when it doesn't
> > > > call kobject_get(). This sort of bug would have been caught in testing
> > > > because it affects the success path so I must be reading the code wrong.
> > > >
> > >
> > > I had the same reading of the code and thought that I was missing something
> > > somewhere.
> > >
> > > There is the same question about 'acpi_get_next_subnode' which is also a
> > > '.get_next_child_node' function, without any ref counting, if I'm correct.
> > >
> >
> > Yeah, but there aren't any ->get/put() ops for the acpi_get_next_subnode()
> > stuff so it's not a problem. (Presumably there is some other sort of
> > refcounting policy there).
>
> OK, so I guess we need to make software_node_get_next_child()
> mimic the behaviour of of_get_next_available_child(), and not
> acpi_get_next_subnode(). Does the attached patch work?
Does not sound unreasonable. Did it get solved, somehow?
Best regards,
Pavel
--
http://www.livejournal.com/~pavelmachek
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next prev parent reply other threads:[~2020-11-25 10:46 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-22 21:05 [PATCH] leds: lp50xx: Fix an error handling path in 'lp50xx_probe_dt()' Christophe JAILLET
2020-09-23 13:27 ` Dan Murphy
2020-09-23 13:35 ` Dan Carpenter
2020-09-23 18:49 ` Christophe JAILLET
2020-09-24 6:49 ` Dan Carpenter
2020-09-28 11:53 ` Heikki Krogerus
2020-11-25 10:46 ` Pavel Machek [this message]
2020-11-25 12:16 ` Heikki Krogerus
2020-11-25 11:01 ` Pavel Machek
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