linux-kernel - Re: [PATCH v2 1/5] hwmon: introduce hwmon_sanitize

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Date:   Wed, 30 Mar 2022 14:50:47 +0800
From:   Xu Yilun <yilun.xu@...el.com>
To:     Michael Walle <michael@...le.cc>
Cc:     Tom Rix <trix@...hat.com>, Jean Delvare <jdelvare@...e.com>,
        Guenter Roeck <linux@...ck-us.net>,
        Andrew Lunn <andrew@...n.ch>,
        Heiner Kallweit <hkallweit1@...il.com>,
        Russell King <linux@...linux.org.uk>,
        "David S . Miller" <davem@...emloft.net>,
        Jakub Kicinski <kuba@...nel.org>,
        Paolo Abeni <pabeni@...hat.com>, linux-hwmon@...r.kernel.org,
        linux-kernel@...r.kernel.org, netdev@...r.kernel.org
Subject: Re: [PATCH v2 1/5] hwmon: introduce hwmon_sanitize_name()

On Tue, Mar 29, 2022 at 06:07:26PM +0200, Michael Walle wrote:
> More and more drivers will check for bad characters in the hwmon name
> and all are using the same code snippet. Consolidate that code by adding
> a new hwmon_sanitize_name() function.
> 
> Signed-off-by: Michael Walle <michael@...le.cc>
> ---
>  Documentation/hwmon/hwmon-kernel-api.rst |  9 ++++-
>  drivers/hwmon/hwmon.c                    | 49 ++++++++++++++++++++++++
>  include/linux/hwmon.h                    |  3 ++
>  3 files changed, 60 insertions(+), 1 deletion(-)
> 
> diff --git a/Documentation/hwmon/hwmon-kernel-api.rst b/Documentation/hwmon/hwmon-kernel-api.rst
> index c41eb6108103..12f4a9bcef04 100644
> --- a/Documentation/hwmon/hwmon-kernel-api.rst
> +++ b/Documentation/hwmon/hwmon-kernel-api.rst
> @@ -50,6 +50,10 @@ register/unregister functions::
>  
>    void devm_hwmon_device_unregister(struct device *dev);
>  
> +  char *hwmon_sanitize_name(const char *name);
> +
> +  char *devm_hwmon_sanitize_name(struct device *dev, const char *name);
> +
>  hwmon_device_register_with_groups registers a hardware monitoring device.
>  The first parameter of this function is a pointer to the parent device.
>  The name parameter is a pointer to the hwmon device name. The registration
> @@ -93,7 +97,10 @@ removal would be too late.
>  
>  All supported hwmon device registration functions only accept valid device
>  names. Device names including invalid characters (whitespace, '*', or '-')
> -will be rejected. The 'name' parameter is mandatory.
> +will be rejected. The 'name' parameter is mandatory. Before calling a
> +register function you should either use hwmon_sanitize_name or
> +devm_hwmon_sanitize_name to replace any invalid characters with an

I suggest                   to duplicate the name and replace ...

Thanks,
Yilun

> +underscore.
>  
>  Using devm_hwmon_device_register_with_info()
>  --------------------------------------------
> diff --git a/drivers/hwmon/hwmon.c b/drivers/hwmon/hwmon.c
> index 989e2c8496dd..619ef9f9a16e 100644
> --- a/drivers/hwmon/hwmon.c
> +++ b/drivers/hwmon/hwmon.c
> @@ -1057,6 +1057,55 @@ void devm_hwmon_device_unregister(struct device *dev)
>  }
>  EXPORT_SYMBOL_GPL(devm_hwmon_device_unregister);
>  
> +static char *__hwmon_sanitize_name(struct device *dev, const char *old_name)
> +{
> +	char *name, *p;
> +
> +	if (dev)
> +		name = devm_kstrdup(dev, old_name, GFP_KERNEL);
> +	else
> +		name = kstrdup(old_name, GFP_KERNEL);
> +	if (!name)
> +		return NULL;
> +
> +	for (p = name; *p; p++)
> +		if (hwmon_is_bad_char(*p))
> +			*p = '_';
> +
> +	return name;
> +}
> +
> +/**
> + * hwmon_sanitize_name - Replaces invalid characters in a hwmon name
> + * @name: NUL-terminated name
> + *
> + * Allocates a new string where any invalid characters will be replaced
> + * by an underscore.
> + *
> + * Returns newly allocated name or %NULL in case of error.
> + */
> +char *hwmon_sanitize_name(const char *name)
> +{
> +	return __hwmon_sanitize_name(NULL, name);
> +}
> +EXPORT_SYMBOL_GPL(hwmon_sanitize_name);
> +
> +/**
> + * devm_hwmon_sanitize_name - resource managed hwmon_sanitize_name()
> + * @dev: device to allocate memory for
> + * @name: NUL-terminated name
> + *
> + * Allocates a new string where any invalid characters will be replaced
> + * by an underscore.
> + *
> + * Returns newly allocated name or %NULL in case of error.
> + */
> +char *devm_hwmon_sanitize_name(struct device *dev, const char *name)
> +{
> +	return __hwmon_sanitize_name(dev, name);
> +}
> +EXPORT_SYMBOL_GPL(devm_hwmon_sanitize_name);
> +
>  static void __init hwmon_pci_quirks(void)
>  {
>  #if defined CONFIG_X86 && defined CONFIG_PCI
> diff --git a/include/linux/hwmon.h b/include/linux/hwmon.h
> index eba380b76d15..4efaf06fd2b8 100644
> --- a/include/linux/hwmon.h
> +++ b/include/linux/hwmon.h
> @@ -461,6 +461,9 @@ void devm_hwmon_device_unregister(struct device *dev);
>  int hwmon_notify_event(struct device *dev, enum hwmon_sensor_types type,
>  		       u32 attr, int channel);
>  
> +char *hwmon_sanitize_name(const char *name);
> +char *devm_hwmon_sanitize_name(struct device *dev, const char *name);
> +
>  /**
>   * hwmon_is_bad_char - Is the char invalid in a hwmon name
>   * @ch: the char to be considered
> -- 
> 2.30.2