drivers/platform/x86/dell/dell-wmi-sysman/passwordattr-interface.c

Source file repositories/reference/linux-study-clean/drivers/platform/x86/dell/dell-wmi-sysman/passwordattr-interface.c

File Facts

System
Linux kernel
Corpus path
drivers/platform/x86/dell/dell-wmi-sysman/passwordattr-interface.c
Extension
.c
Size
4293 bytes
Lines
152
Domain
Driver Families
Bucket
drivers/platform
Inferred role
Driver Families: implementation source
Status
source implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

// SPDX-License-Identifier: GPL-2.0
/*
 * Functions corresponding to SET password methods under BIOS attributes interface GUID
 *
 *  Copyright (c) 2020 Dell Inc.
 */

#include <linux/wmi.h>
#include "dell-wmi-sysman.h"

static int call_password_interface(struct wmi_device *wdev, char *in_args, size_t size)
{
	struct acpi_buffer output = {ACPI_ALLOCATE_BUFFER, NULL};
	struct acpi_buffer input;
	union acpi_object *obj;
	acpi_status status;
	int ret = -EIO;

	input.length =  (acpi_size) size;
	input.pointer = in_args;
	status = wmidev_evaluate_method(wdev, 0, 1, &input, &output);
	if (ACPI_FAILURE(status))
		return -EIO;
	obj = (union acpi_object *)output.pointer;
	if (obj->type == ACPI_TYPE_INTEGER)
		ret = obj->integer.value;

	kfree(output.pointer);
	/* let userland know it may need to check is_password_set again */
	kobject_uevent(&wmi_priv.class_dev->kobj, KOBJ_CHANGE);
	return map_wmi_error(ret);
}

/**
 * set_new_password() - Sets a system admin password
 * @password_type: The type of password to set
 * @new: The new password
 *
 * Sets the password using plaintext interface
 */
int set_new_password(const char *password_type, const char *new)
{
	size_t password_type_size, current_password_size, new_size;
	size_t security_area_size, buffer_size;
	char *buffer = NULL, *start;
	char *current_password;
	int ret;

	mutex_lock(&wmi_priv.mutex);
	if (!wmi_priv.password_attr_wdev) {
		ret = -ENODEV;
		goto out;
	}
	if (strcmp(password_type, "Admin") == 0) {
		current_password = wmi_priv.current_admin_password;
	} else if (strcmp(password_type, "System") == 0) {
		current_password = wmi_priv.current_system_password;
	} else {
		ret = -EINVAL;
		dev_err(&wmi_priv.password_attr_wdev->dev, "unknown password type %s\n",
			password_type);
		goto out;
	}

	/* build/calculate buffer */
	security_area_size = calculate_security_buffer(wmi_priv.current_admin_password);
	password_type_size = calculate_string_buffer(password_type);
	current_password_size = calculate_string_buffer(current_password);
	new_size = calculate_string_buffer(new);
	buffer_size = security_area_size + password_type_size + current_password_size + new_size;
	buffer = kzalloc(buffer_size, GFP_KERNEL);
	if (!buffer) {
		ret = -ENOMEM;
		goto out;
	}

	/* build security area */
	populate_security_buffer(buffer, wmi_priv.current_admin_password);

	/* build variables to set */
	start = buffer + security_area_size;
	ret = populate_string_buffer(start, password_type_size, password_type);
	if (ret < 0)
		goto out;

	start += ret;
	ret = populate_string_buffer(start, current_password_size, current_password);
	if (ret < 0)
		goto out;

Annotation

Implementation Notes