From: Mark Brown <broonie@kernel.org>
To: Dan Carpenter <dan.carpenter@oracle.com>
Cc: "Robin Murphy" <robin.murphy@arm.com>,
"Lorenzo Pieralisi" <lorenzo.pieralisi@arm.com>,
"Simon Xue" <xxm@rock-chips.com>, "Rob Herring" <robh@kernel.org>,
"Krzysztof Wilczyński" <kw@linux.com>,
"Bjorn Helgaas" <bhelgaas@google.com>,
"Heiko Stuebner" <heiko@sntech.de>,
"Liam Girdwood" <lgirdwood@gmail.com>,
"Kever Yang" <kever.yang@rock-chips.com>,
"Shawn Lin" <shawn.lin@rock-chips.com>,
linux-pci@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
linux-rockchip@lists.infradead.org,
kernel-janitors@vger.kernel.org
Subject: Re: [PATCH] PCI: rockchip-dwc: Potential error pointer dereference in probe
Date: Fri, 13 Aug 2021 16:53:50 +0100 [thread overview]
Message-ID: <20210813155350.GC5209@sirena.org.uk> (raw)
In-Reply-To: <20210813154505.GC7722@kadam>
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On Fri, Aug 13, 2021 at 06:45:05PM +0300, Dan Carpenter wrote:
> On Fri, Aug 13, 2021 at 03:32:50PM +0100, Mark Brown wrote:
> > On Fri, Aug 13, 2021 at 03:01:10PM +0100, Robin Murphy wrote:
> > > Indeed I've thought before that it would be nice if regulators worked like
> > > GPIOs, where the absence of an optional one does give you NULL, and most of
> > > the API is also NULL-safe. Probably a pretty big job though...
> > It also encourages *really* bad practice with error handling
> I'm not necessarily 100% positive what you mean by this. I think you
> mean you don't like when people pass invalid pointers to free functions?
No, it's the case where people don't bother checking if they got the
regulator in the first place, don't bother checking if when they tried
to enable the regulator that actually worked, and don't do whatever
extra handling they need to do to configure the system for the fact that
one of the power supplies is missing. It really only helps in the case
where you can just ignore the regulator completely.
> But making regulator code NULL-safe wouldn't affect error handling
> because NULL wouldn't be an error.
>
> p = get_optional();
> if (IS_ERR(p))
> return PTR_ERR(p);
> enable(p);
Your example already misses the error handling on enable...
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WARNING: multiple messages have this Message-ID (diff)
From: Mark Brown <broonie@kernel.org>
To: Dan Carpenter <dan.carpenter@oracle.com>
Cc: "Robin Murphy" <robin.murphy@arm.com>,
"Lorenzo Pieralisi" <lorenzo.pieralisi@arm.com>,
"Simon Xue" <xxm@rock-chips.com>, "Rob Herring" <robh@kernel.org>,
"Krzysztof Wilczyński" <kw@linux.com>,
"Bjorn Helgaas" <bhelgaas@google.com>,
"Heiko Stuebner" <heiko@sntech.de>,
"Liam Girdwood" <lgirdwood@gmail.com>,
"Kever Yang" <kever.yang@rock-chips.com>,
"Shawn Lin" <shawn.lin@rock-chips.com>,
linux-pci@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
linux-rockchip@lists.infradead.org,
kernel-janitors@vger.kernel.org
Subject: Re: [PATCH] PCI: rockchip-dwc: Potential error pointer dereference in probe
Date: Fri, 13 Aug 2021 16:53:50 +0100 [thread overview]
Message-ID: <20210813155350.GC5209@sirena.org.uk> (raw)
In-Reply-To: <20210813154505.GC7722@kadam>
[-- Attachment #1.1: Type: text/plain, Size: 1322 bytes --]
On Fri, Aug 13, 2021 at 06:45:05PM +0300, Dan Carpenter wrote:
> On Fri, Aug 13, 2021 at 03:32:50PM +0100, Mark Brown wrote:
> > On Fri, Aug 13, 2021 at 03:01:10PM +0100, Robin Murphy wrote:
> > > Indeed I've thought before that it would be nice if regulators worked like
> > > GPIOs, where the absence of an optional one does give you NULL, and most of
> > > the API is also NULL-safe. Probably a pretty big job though...
> > It also encourages *really* bad practice with error handling
> I'm not necessarily 100% positive what you mean by this. I think you
> mean you don't like when people pass invalid pointers to free functions?
No, it's the case where people don't bother checking if they got the
regulator in the first place, don't bother checking if when they tried
to enable the regulator that actually worked, and don't do whatever
extra handling they need to do to configure the system for the fact that
one of the power supplies is missing. It really only helps in the case
where you can just ignore the regulator completely.
> But making regulator code NULL-safe wouldn't affect error handling
> because NULL wouldn't be an error.
>
> p = get_optional();
> if (IS_ERR(p))
> return PTR_ERR(p);
> enable(p);
Your example already misses the error handling on enable...
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_______________________________________________
Linux-rockchip mailing list
Linux-rockchip@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-rockchip
WARNING: multiple messages have this Message-ID (diff)
From: Mark Brown <broonie@kernel.org>
To: Dan Carpenter <dan.carpenter@oracle.com>
Cc: "Robin Murphy" <robin.murphy@arm.com>,
"Lorenzo Pieralisi" <lorenzo.pieralisi@arm.com>,
"Simon Xue" <xxm@rock-chips.com>, "Rob Herring" <robh@kernel.org>,
"Krzysztof Wilczyński" <kw@linux.com>,
"Bjorn Helgaas" <bhelgaas@google.com>,
"Heiko Stuebner" <heiko@sntech.de>,
"Liam Girdwood" <lgirdwood@gmail.com>,
"Kever Yang" <kever.yang@rock-chips.com>,
"Shawn Lin" <shawn.lin@rock-chips.com>,
linux-pci@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
linux-rockchip@lists.infradead.org,
kernel-janitors@vger.kernel.org
Subject: Re: [PATCH] PCI: rockchip-dwc: Potential error pointer dereference in probe
Date: Fri, 13 Aug 2021 16:53:50 +0100 [thread overview]
Message-ID: <20210813155350.GC5209@sirena.org.uk> (raw)
In-Reply-To: <20210813154505.GC7722@kadam>
[-- Attachment #1.1: Type: text/plain, Size: 1322 bytes --]
On Fri, Aug 13, 2021 at 06:45:05PM +0300, Dan Carpenter wrote:
> On Fri, Aug 13, 2021 at 03:32:50PM +0100, Mark Brown wrote:
> > On Fri, Aug 13, 2021 at 03:01:10PM +0100, Robin Murphy wrote:
> > > Indeed I've thought before that it would be nice if regulators worked like
> > > GPIOs, where the absence of an optional one does give you NULL, and most of
> > > the API is also NULL-safe. Probably a pretty big job though...
> > It also encourages *really* bad practice with error handling
> I'm not necessarily 100% positive what you mean by this. I think you
> mean you don't like when people pass invalid pointers to free functions?
No, it's the case where people don't bother checking if they got the
regulator in the first place, don't bother checking if when they tried
to enable the regulator that actually worked, and don't do whatever
extra handling they need to do to configure the system for the fact that
one of the power supplies is missing. It really only helps in the case
where you can just ignore the regulator completely.
> But making regulator code NULL-safe wouldn't affect error handling
> because NULL wouldn't be an error.
>
> p = get_optional();
> if (IS_ERR(p))
> return PTR_ERR(p);
> enable(p);
Your example already misses the error handling on enable...
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_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2021-08-13 15:54 UTC|newest]
Thread overview: 48+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-13 11:33 [PATCH] PCI: rockchip-dwc: Potential error pointer dereference in probe Dan Carpenter
2021-08-13 11:33 ` Dan Carpenter
2021-08-13 11:33 ` Dan Carpenter
2021-08-13 12:55 ` Robin Murphy
2021-08-13 12:55 ` Robin Murphy
2021-08-13 12:55 ` Robin Murphy
2021-08-13 13:34 ` Rob Herring
2021-08-13 13:34 ` Rob Herring
2021-08-13 13:34 ` Rob Herring
2021-08-13 13:47 ` Robin Murphy
2021-08-13 13:47 ` Robin Murphy
2021-08-13 13:47 ` Robin Murphy
2021-08-13 15:57 ` Rob Herring
2021-08-13 15:57 ` Rob Herring
2021-08-13 15:57 ` Rob Herring
2021-08-13 16:01 ` Mark Brown
2021-08-13 16:01 ` Mark Brown
2021-08-13 16:01 ` Mark Brown
2021-08-13 13:54 ` Dan Carpenter
2021-08-13 13:54 ` Dan Carpenter
2021-08-13 13:54 ` Dan Carpenter
2021-08-13 14:01 ` Robin Murphy
2021-08-13 14:01 ` Robin Murphy
2021-08-13 14:01 ` Robin Murphy
2021-08-13 14:12 ` Dan Carpenter
2021-08-13 14:12 ` Dan Carpenter
2021-08-13 14:12 ` Dan Carpenter
2021-08-13 14:26 ` [PATCH v2] " Dan Carpenter
2021-08-13 14:26 ` Dan Carpenter
2021-08-13 14:26 ` Dan Carpenter
2021-08-23 16:15 ` Lorenzo Pieralisi
2021-08-23 16:15 ` Lorenzo Pieralisi
2021-08-23 16:15 ` Lorenzo Pieralisi
2021-08-13 14:32 ` [PATCH] " Mark Brown
2021-08-13 14:32 ` Mark Brown
2021-08-13 14:32 ` Mark Brown
2021-08-13 15:00 ` Robin Murphy
2021-08-13 15:00 ` Robin Murphy
2021-08-13 15:00 ` Robin Murphy
2021-08-13 15:30 ` Mark Brown
2021-08-13 15:30 ` Mark Brown
2021-08-13 15:30 ` Mark Brown
2021-08-13 15:45 ` Dan Carpenter
2021-08-13 15:45 ` Dan Carpenter
2021-08-13 15:45 ` Dan Carpenter
2021-08-13 15:53 ` Mark Brown [this message]
2021-08-13 15:53 ` Mark Brown
2021-08-13 15:53 ` Mark Brown
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