From: "Russell King (Oracle)" <linux@armlinux.org.uk>
To: Tony Lindgren <tony@atomide.com>
Cc: Liang He <windhl@126.com>,
andre.przywara@arm.com, thierry.reding@gmail.com,
jonathanh@nvidia.com, linux-arm-kernel@lists.infradead.org,
linux-omap@vger.kernel.org, linux-tegra@vger.kernel.org,
Krzysztof Kozlowski <krzk@kernel.org>
Subject: Re: [PATCH] arm/mach: Hold reference returned by of_find_xxx APIs
Date: Tue, 28 Jun 2022 17:16:04 +0100 [thread overview]
Message-ID: <YrspRE+g7QvzOvgr@shell.armlinux.org.uk> (raw)
In-Reply-To: <Yrp8sUMdmfYsiUsD@atomide.com>
On Tue, Jun 28, 2022 at 06:59:45AM +0300, Tony Lindgren wrote:
> * Liang He <windhl@126.com> [220621 12:14]:
> > diff --git a/arch/arm/mach-omap2/pmic-cpcap.c b/arch/arm/mach-omap2/pmic-cpcap.c
> > index 668dc84fd31e..a7368d657aa8 100644
> > --- a/arch/arm/mach-omap2/pmic-cpcap.c
> > +++ b/arch/arm/mach-omap2/pmic-cpcap.c
> > @@ -238,8 +238,11 @@ static struct omap_voltdm_pmic omap4_fan_iva = {
> > int __init omap4_cpcap_init(void)
> > {
> > struct voltagedomain *voltdm;
> > + struct device_node *np;
> >
> > - if (!of_find_compatible_node(NULL, NULL, "motorola,cpcap"))
> > + np = of_find_compatible_node(NULL, NULL, "motorola,cpcap");
> > + of_node_put(np);
> > + if (!np)
> > return -ENODEV;
>
> Hmm so here you are checking for !np after of_node_put()?
This is permissible, because the value of the _pointer_ is being
checked without dereferencing the pointer. So the fact that the
node may have been freed is actually immaterial.
--
RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
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next prev parent reply other threads:[~2022-06-28 16:25 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-06-21 9:19 [PATCH] arm/mach: Hold reference returned by of_find_xxx APIs Liang He
2022-06-22 8:51 ` Krzysztof Kozlowski
2022-06-28 3:59 ` Tony Lindgren
2022-06-28 4:05 ` Liang He
2022-06-28 16:16 ` Russell King (Oracle) [this message]
2022-06-29 8:37 ` Tony Lindgren
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