[PATCH v2 4/4] Updating a deprecated use of strcpy in button.c file.

[PATCH v2 4/4] Updating a deprecated use of strcpy in button.c file.

[Muhammad Qasim Abdul Majeed]

Replacing strcpy with strscpy.
strcpy is a deprecated function.
It should be removed from the kernel source.

Link: https://github.com/KSPP/linux/issues/88

Signed-off-by: Muhammad Qasim Abdul Majeed <qasim.majeed20@gmail.com>

Hi All,

strscpy requires destination size for pointers. (https://elixir.bootlin.com/linux/latest/source/include/linux/string.h#L95)
acpi_device_name is defined as 40 bytes no macro definition for length (https://elixir.bootlin.com/linux/latest/source/include/acpi/acpi_bus.h#L224). 
Placing a constant number to copy is not a good idea. If name lenght chages in future it will be an issue. Replacing name array with acpi_device_name macro for this reason.

ACPI compile time arrays should be defined using a macro. It keeps code change consistent accross the source (#define ACPI_DEVICE_NAME_LENGTH) 
If this suggestions seems good to you, I'll push the patch for the sugested change.

Best Regards,
Qasim

---
	v1-> v2: It fixes the build issue, removes char* name and use acpi_device_name for simplicity.
 drivers/acpi/button.c | 13 ++++++-------
 1 file changed, 6 insertions(+), 7 deletions(-)

diff --git a/drivers/acpi/button.c b/drivers/acpi/button.c
index cc61020756be..9dda4a3998f8 100644
--- a/drivers/acpi/button.c
+++ b/drivers/acpi/button.c
@@ -521,7 +521,7 @@ static int acpi_button_add(struct acpi_device *device)
 	struct input_dev *input;
 	const char *hid = acpi_device_hid(device);
 	acpi_status status;
-	char *name, *class;
+	char *class;
 	int error = 0;
 
 	if (!strcmp(hid, ACPI_BUTTON_HID_LID) &&
@@ -540,27 +540,26 @@ static int acpi_button_add(struct acpi_device *device)
 		goto err_free_button;
 	}
 
-	name = acpi_device_name(device);
 	class = acpi_device_class(device);
 
 	if (!strcmp(hid, ACPI_BUTTON_HID_POWER) ||
 	    !strcmp(hid, ACPI_BUTTON_HID_POWERF)) {
 		button->type = ACPI_BUTTON_TYPE_POWER;
 		handler = acpi_button_notify;
-		strcpy(name, ACPI_BUTTON_DEVICE_NAME_POWER);
+		strscpy(acpi_device_name(device), ACPI_BUTTON_DEVICE_NAME_POWER);
 		sprintf(class, "%s/%s",
 			ACPI_BUTTON_CLASS, ACPI_BUTTON_SUBCLASS_POWER);
 	} else if (!strcmp(hid, ACPI_BUTTON_HID_SLEEP) ||
 		   !strcmp(hid, ACPI_BUTTON_HID_SLEEPF)) {
 		button->type = ACPI_BUTTON_TYPE_SLEEP;
 		handler = acpi_button_notify;
-		strcpy(name, ACPI_BUTTON_DEVICE_NAME_SLEEP);
+		strscpy(acpi_device_name(device), ACPI_BUTTON_DEVICE_NAME_SLEEP);
 		sprintf(class, "%s/%s",
 			ACPI_BUTTON_CLASS, ACPI_BUTTON_SUBCLASS_SLEEP);
 	} else if (!strcmp(hid, ACPI_BUTTON_HID_LID)) {
 		button->type = ACPI_BUTTON_TYPE_LID;
 		handler = acpi_lid_notify;
-		strcpy(name, ACPI_BUTTON_DEVICE_NAME_LID);
+		strscpy(acpi_device_name(device), ACPI_BUTTON_DEVICE_NAME_LID);
 		sprintf(class, "%s/%s",
 			ACPI_BUTTON_CLASS, ACPI_BUTTON_SUBCLASS_LID);
 		input->open = acpi_lid_input_open;
@@ -579,7 +578,7 @@ static int acpi_button_add(struct acpi_device *device)
 
 	snprintf(button->phys, sizeof(button->phys), "%s/button/input0", hid);
 
-	input->name = name;
+	input->name = acpi_device_name(device);
 	input->phys = button->phys;
 	input->id.bustype = BUS_HOST;
 	input->id.product = button->type;
@@ -636,7 +635,7 @@ static int acpi_button_add(struct acpi_device *device)
 	}
 
 	device_init_wakeup(&device->dev, true);
-	pr_info("%s [%s]\n", name, acpi_device_bid(device));
+	pr_info("%s [%s]\n", input->name, acpi_device_bid(device));
 	return 0;
 
 err_input_unregister:
-- 
2.34.1