From: Bjorn Helgaas <helgaas@kernel.org>
To: Jiecheng Wu <jasonwood2031@gmail.com>
Cc: linux-pci@vger.kernel.org, Keith Busch <keith.busch@intel.com>,
Sinan Kaya <okaya@kernel.org>,
Oza Pawandeep <poza@codeaurora.org>
Subject: Re: [PATCH] dpc.c: fix missing return value check of pci_find_ext_capability()
Date: Wed, 12 Sep 2018 15:51:20 -0500 [thread overview]
Message-ID: <20180912205119.GL118330@bhelgaas-glaptop.roam.corp.google.com> (raw)
In-Reply-To: <20180817081719.11156-1-jasonwood2031@gmail.com>
[+cc Keith, Sinan, Oza]
Please run "git log --oneline drivers/pci/pcie/dpc.c" and make your
subject match the existing style.
Also, please run "scripts/get_maintainer.pl -f drivers/pci/pcie/dpc.c" and
cc people who seem interested in the file.
On Fri, Aug 17, 2018 at 04:17:19PM +0800, Jiecheng Wu wrote:
> Function dpc_probe() defined in drivers/pci/pcie/dpc.c calls pci_find_ext_capability(). Function pci_find_ext_capability() returns the address of the requested extended capability structure within the device's PCI configuration space or 0 if the device does not support it. The return value of this function should be checked against 0.
Needs a signed-off-by before I can apply it. See
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/process/submitting-patches.rst#n416
> ---
> drivers/pci/pcie/dpc.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/drivers/pci/pcie/dpc.c b/drivers/pci/pcie/dpc.c
> index f03279f..30ff550 100644
> --- a/drivers/pci/pcie/dpc.c
> +++ b/drivers/pci/pcie/dpc.c
> @@ -226,6 +226,8 @@ static int dpc_probe(struct pcie_device *dev)
> return -ENOMEM;
>
> dpc->cap_pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_DPC);
> + if (!dpc->cap_pos)
> + return -ENODEV;
Keith is right that we shouldn't get here if there's no DPC
capability. But it's a pain for readers to verify that because that
check is buried in the portdrv driver, so I'm not opposed to adding a
check here.
If we do add a check, I would move the pci_find_ext_capability() and
the check up above the devm_kzalloc(). I know devm will take care of
the cleanup, but I think it's better style to check for things that
require no cleanup first, before doing the things that do require
cleanup.
> dpc->dev = dev;
> set_service_data(dev, dpc);
>
> --
> 2.6.4
>
prev parent reply other threads:[~2018-09-13 1:57 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-08-17 8:17 [PATCH] dpc.c: fix missing return value check of pci_find_ext_capability() Jiecheng Wu
2018-08-17 10:55 ` poza
2018-08-17 14:03 ` Keith Busch
2018-09-12 20:51 ` Bjorn Helgaas [this message]
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