Re: [PATCH v4 1/2] hwmon: introduce hwmon_sanitize_name()

From: Tom Rix
Date: Tue Apr 05 2022 - 19:42:00 EST



On 4/5/22 2:24 AM, 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@xxxxxxxx>
---
Documentation/hwmon/hwmon-kernel-api.rst | 16 +++++++
drivers/hwmon/hwmon.c | 53 ++++++++++++++++++++++++
include/linux/hwmon.h | 3 ++
3 files changed, 72 insertions(+)

diff --git a/Documentation/hwmon/hwmon-kernel-api.rst b/Documentation/hwmon/hwmon-kernel-api.rst
index c41eb6108103..e2975d5caf34 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
@@ -95,6 +99,18 @@ 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.
+If the driver doesn't use a static device name (for example it uses
+dev_name()), and therefore cannot make sure the name only contains valid
+characters, hwmon_sanitize_name can be used. This convenience function
+will duplicate the string and replace any invalid characters with an
+underscore. It will allocate memory for the new string and it is the
+responsibility of the caller to release the memory when the device is
+removed.
+
+devm_hwmon_sanitize_name is the resource managed version of
+hwmon_sanitize_name; the memory will be freed automatically on device
+removal.
+
Using devm_hwmon_device_register_with_info()
--------------------------------------------
diff --git a/drivers/hwmon/hwmon.c b/drivers/hwmon/hwmon.c
index 989e2c8496dd..5915ccfdb7d9 100644
--- a/drivers/hwmon/hwmon.c
+++ b/drivers/hwmon/hwmon.c
@@ -1057,6 +1057,59 @@ 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 ERR_PTR(-ENOMEM);
+
+ 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. It is the responsibility of the caller to release
+ * the memory.
+ *
+ * Returns newly allocated name, or ERR_PTR on 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 ERR_PTR on error.
+ */
+char *devm_hwmon_sanitize_name(struct device *dev, const char *name)
+{
+ if (!dev)
+ return ERR_PTR(-EINVAL);
+
+ 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);

Thanks for the changes.

Reviewed-by: Tom Rix <trix@xxxxxxxxxx>

+
/**
* hwmon_is_bad_char - Is the char invalid in a hwmon name
* @ch: the char to be considered