Re: [PATCH v13 01/18] EDAC: Add support for EDAC device features control

[Jonathan Cameron <Jonathan.Cameron@Huawei.com>]

On Wed, 9 Oct 2024 13:41:02 +0100
<shiju.jose@huawei.com> wrote:

> From: Shiju Jose <shiju.jose@huawei.com>
> 
> Add generic EDAC device features control supports registering
> RAS features supported in the system. Driver exposes features
> control attributes to userspace in
> /sys/bus/edac/devices/<dev-name>/<ras-feature>/
> 
> Co-developed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
> Signed-off-by: Shiju Jose <shiju.jose@huawei.com>
Hi Shiju,

Spotted a few minor bugs in here that I'd missed in internal
review :( See below.

Jonathan

> ---
>  drivers/edac/edac_device.c | 105 +++++++++++++++++++++++++++++++++++++
>  include/linux/edac.h       |  32 +++++++++++
>  2 files changed, 137 insertions(+)
> 
> diff --git a/drivers/edac/edac_device.c b/drivers/edac/edac_device.c
> index 621dc2a5d034..0b8aa8150239 100644
> --- a/drivers/edac/edac_device.c
> +++ b/drivers/edac/edac_device.c


> +
> +/**
> + * edac_dev_register - register device for RAS features with EDAC
> + * @parent: client device.
> + * @name: client device's name.
> + * @private: parent driver's data to store in the context if any.
> + * @num_features: number of RAS features to register.
> + * @ras_features: list of RAS features to register.
> + *
> + * Return:
> + *  * %0       - Success.
> + *  * %-EINVAL - Invalid parameters passed.
> + *  * %-ENOMEM - Dynamic memory allocation failed.
> + *
> + * The new edac_dev_feat_ctx would be freed automatically.
> + */
> +int edac_dev_register(struct device *parent, char *name,
> +		      void *private, int num_features,
> +		      const struct edac_dev_feature *ras_features)
> +{

...

> +	ret = device_register(&ctx->dev);
> +	if (ret) {
> +		put_device(&ctx->dev);
> +		goto groups_free;
> +		return ret;

Unreachable line. However, shouldn't have the goto here
as put_device() should result in the release being called
in which case this is a double free. So drop the goto and keep
the return.


> +	}
> +
> +	return devm_add_action_or_reset(parent, edac_dev_unreg, &ctx->dev);
> +
> +groups_free:
> +	kfree(ras_attr_groups);
> +ctx_free:
> +	kfree(ctx);
> +	return ret;
> +}
> +EXPORT_SYMBOL_GPL(edac_dev_register);
> diff --git a/include/linux/edac.h b/include/linux/edac.h
> index b4ee8961e623..1db008a82690 100644
> --- a/include/linux/edac.h
> +++ b/include/linux/edac.h
> @@ -661,4 +661,36 @@ static inline struct dimm_info *edac_get_dimm(struct mem_ctl_info *mci,


> +/* EDAC device feature information structure */
> +struct edac_dev_data {
> +	u8 instance;
> +	void *private;
> +};
> +
> +struct device;

That forwards def doesn't work as this header needs to include
enough information to establish layout of struct edac_dev_feat_ctx.
Header already includes linux/device.h so just drop this.


> +
> +struct edac_dev_feat_ctx {
> +	struct device dev;
> +	void *private;
> +};
> +
> +struct edac_dev_feature {
> +	enum edac_dev_feat ft_type;
> +	u8 instance;
> +	void *ctx;
> +};
> +
> +int edac_dev_register(struct device *parent, char *dev_name,
> +		      void *parent_pvt_data, int num_features,
> +		      const struct edac_dev_feature *ras_features);
>  #endif /* _LINUX_EDAC_H_ */