2022-12-20 09:41:08

by Aleksandr Burakov

Subject: [PATCH] PCI: amlogic: The check for devm_add_action_or_reset's return value added

The return value of the function devm_add_action_or_reset() was not
checked hence an error code would not be returned.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Fixes: 9c0ef6d34fdb ("PCI: amlogic: Add the Amlogic Meson PCIe controller driver")
Signed-off-by: Aleksandr Burakov <[email protected]>
---
drivers/pci/controller/dwc/pci-meson.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/pci/controller/dwc/pci-meson.c b/drivers/pci/controller/dwc/pci-meson.c
index c1527693bed9..3d82f0b65480 100644
--- a/drivers/pci/controller/dwc/pci-meson.c
+++ b/drivers/pci/controller/dwc/pci-meson.c
@@ -187,9 +187,13 @@ static inline struct clk *meson_pcie_probe_clock(struct device *dev,
return ERR_PTR(ret);
}

- devm_add_action_or_reset(dev,
+ ret = devm_add_action_or_reset(dev,
(void (*) (void *))clk_disable_unprepare,
clk);
+ if (ret) {
+ dev_err(dev, "couldn't reset clk\n");
+ return ERR_PTR(ret);
+ }

return clk;
}
--
2.25.1

2022-12-29 20:20:09

by Bjorn Helgaas

Subject: Re: [PATCH] PCI: amlogic: The check for devm_add_action_or_reset's return value added

Hi Aleksandr,

Thanks for the patch!

On Tue, Dec 20, 2022 at 12:21:37PM +0300, Aleksandr Burakov wrote:
> The return value of the function devm_add_action_or_reset() was not
> checked hence an error code would not be returned.

You can save Lorenzo and Krzysztof some work by:

- Rewording the subject line in the typical "<verb> <object>"
imperative form, e.g., "Check for devm_add_action_or_reset()
failure"

- Rewording the commit log similarly. Note that the existing commit
only describes the current situation and doesn't actually say what
the patch does.

Here's a good guide to commit logs: https://cbea.ms/git-commit/

> Fixes: 9c0ef6d34fdb ("PCI: amlogic: Add the Amlogic Meson PCIe controller driver")
> Signed-off-by: Aleksandr Burakov <[email protected]>
> ---
> drivers/pci/controller/dwc/pci-meson.c | 6 +++++-
> 1 file changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/pci/controller/dwc/pci-meson.c b/drivers/pci/controller/dwc/pci-meson.c
> index c1527693bed9..3d82f0b65480 100644
> --- a/drivers/pci/controller/dwc/pci-meson.c
> +++ b/drivers/pci/controller/dwc/pci-meson.c
> @@ -187,9 +187,13 @@ static inline struct clk *meson_pcie_probe_clock(struct device *dev,
> return ERR_PTR(ret);
> }
>
> - devm_add_action_or_reset(dev,
> + ret = devm_add_action_or_reset(dev,
> (void (*) (void *))clk_disable_unprepare,
> clk);
> + if (ret) {
> + dev_err(dev, "couldn't reset clk\n");
> + return ERR_PTR(ret);
> + }
>
> return clk;
> }
> --
> 2.25.1
>

2022-12-29 21:55:05

by Christophe JAILLET

Subject: Re: [PATCH] PCI: amlogic: The check for devm_add_action_or_reset's return value added

Le 20/12/2022 à 10:21, Aleksandr Burakov a écrit :
> The return value of the function devm_add_action_or_reset() was not
> checked hence an error code would not be returned.
>
> Found by Linux Verification Center (linuxtesting.org) with SVACE.
>
> Fixes: 9c0ef6d34fdb ("PCI: amlogic: Add the Amlogic Meson PCIe controller driver")
> Signed-off-by: Aleksandr Burakov <[email protected]>
> ---
> drivers/pci/controller/dwc/pci-meson.c | 6 +++++-
> 1 file changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/pci/controller/dwc/pci-meson.c b/drivers/pci/controller/dwc/pci-meson.c
> index c1527693bed9..3d82f0b65480 100644
> --- a/drivers/pci/controller/dwc/pci-meson.c
> +++ b/drivers/pci/controller/dwc/pci-meson.c
> @@ -187,9 +187,13 @@ static inline struct clk *meson_pcie_probe_clock(struct device *dev,
> return ERR_PTR(ret);
> }
>
> - devm_add_action_or_reset(dev,
> + ret = devm_add_action_or_reset(dev,
> (void (*) (void *))clk_disable_unprepare,

Hi,

using devm_clk_get_enabled() a few lines above would be IMHO much more
elegant than these casts.

This also saves a few LoC and avoid some other warnings/issues. (see [1])

Such an approach has already been used in [2].

Just my 2c,

CJ

[1]: https://lore.kernel.org/all/[email protected]/
[2]: https://lore.kernel.org/all/[email protected]/

> clk);
> + if (ret) {
> + dev_err(dev, "couldn't reset clk\n");
> + return ERR_PTR(ret);
> + }
>
> return clk;
> }