[v11,03/14] HP BIOSCFG driver - bioscfg
Commit Message
HP BIOS Configuration driver purpose is to provide a driver supporting
the latest sysfs class firmware attributes framework allowing the user
to change BIOS settings and security solutions on HP Inc.’s commercial
notebooks.
Many features of HP Commercial notebooks can be managed using Windows
Management Instrumentation (WMI). WMI is an implementation of Web-Based
Enterprise Management (WBEM) that provides a standards-based interface
for changing and monitoring system settings. HP BIOSCFG driver provides
a native Linux solution and the exposed features facilitates the
migration to Linux environments.
The Linux security features to be provided in hp-bioscfg driver enables
managing the BIOS settings and security solutions via sysfs, a virtual
filesystem that can be used by user-mode applications. The new
documentation cover HP-specific firmware sysfs attributes such Secure
Platform Management and Sure Start. Each section provides security
feature description and identifies sysfs directories and files exposed
by the driver.
Many HP Commercial notebooks include a feature called Secure Platform
Management (SPM), which replaces older password-based BIOS settings
management with public key cryptography. PC secure product management
begins when a target system is provisioned with cryptographic keys
that are used to ensure the integrity of communications between system
management utilities and the BIOS.
HP Commercial notebooks have several BIOS settings that control its
behaviour and capabilities, many of which are related to security.
To prevent unauthorized changes to these settings, the system can
be configured to use a cryptographic signature-based authorization
string that the BIOS will use to verify authorization to modify the
setting.
Linux Security components are under development and not published yet.
The only linux component is the driver (hp bioscfg) at this time.
Other published security components are under Windows.
Signed-off-by: Jorge Lopez <jorge.lopez2@hp.com>
---
Based on the latest platform-drivers-x86.git/for-next
---
drivers/platform/x86/hp/hp-bioscfg/bioscfg.c | 961 +++++++++++++++++++
1 file changed, 961 insertions(+)
create mode 100644 drivers/platform/x86/hp/hp-bioscfg/bioscfg.c
Comments
On 2023-04-20 11:54:43-0500, Jorge Lopez wrote:
> ---
> drivers/platform/x86/hp/hp-bioscfg/bioscfg.c | 961 +++++++++++++++++++
> 1 file changed, 961 insertions(+)
> create mode 100644 drivers/platform/x86/hp/hp-bioscfg/bioscfg.c
>
> diff --git a/drivers/platform/x86/hp/hp-bioscfg/bioscfg.c b/drivers/platform/x86/hp/hp-bioscfg/bioscfg.c
> new file mode 100644
> index 000000000000..4b0d4f56e65f
> --- /dev/null
> +++ b/drivers/platform/x86/hp/hp-bioscfg/bioscfg.c
> @@ -0,0 +1,961 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Common methods for use with hp-bioscfg driver
> + *
> + * Copyright (c) 2022 HP Development Company, L.P.
> + */
> +
> +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
> +
> +#include <linux/fs.h>
> +#include <linux/module.h>
> +#include <linux/kernel.h>
> +#include <linux/wmi.h>
> +#include "bioscfg.h"
> +#include "../../firmware_attributes_class.h"
> +#include <linux/nls.h>
> +#include <linux/errno.h>
> +
> +MODULE_AUTHOR("Jorge Lopez <jorge.lopez2@hp.com>");
> +MODULE_DESCRIPTION("HP BIOS Configuration Driver");
> +MODULE_LICENSE("GPL");
> +
> +struct bioscfg_priv bioscfg_drv = {
> + .mutex = __MUTEX_INITIALIZER(bioscfg_drv.mutex),
> +};
> +
> +static struct class *fw_attr_class;
> +
> +int get_integer_from_buffer(int **buffer, u32 *buffer_size, int *integer)
> +{
It would be clearer to use u32 or s32 instead of int/integer.
This should also take a "u8 **buffer" to avoid casts in all the callers.
> + int *ptr = PTR_ALIGN(*buffer, 4);
> +
> + /* Ensure there is enough space remaining to read the integer */
> + if (*buffer_size < sizeof(int))
> + return -EINVAL;
> +
> + *integer = *(ptr++);
> + *buffer = ptr;
> + *buffer_size -= sizeof(int);
> +
> + return 0;
> +}
> +
> +
> +int get_string_from_buffer(u8 **buffer, u32 *buffer_size, char *dst, u32 dst_size)
> +{
> + u16 *src = (u16 *)*buffer;
> + u16 src_size;
> +
> + u16 size;
> + int i;
> + int escape = 0;
> + int conv_dst_size;
> +
> + if (*buffer_size < sizeof(u16))
> + return -EINVAL;
> +
> + src_size = *(src++);
> + /* size value in u16 chars */
> + size = src_size / sizeof(u16);
> +
> + /* Ensure there is enough space remaining to read and convert
> + * the string
> + */
> + if (*buffer_size < src_size)
> + return -EINVAL;
> +
> + for (i = 0; i < size; i++)
> + if (src[i] == '\\' ||
> + src[i] == '\r' ||
> + src[i] == '\n' ||
> + src[i] == '\t')
> + escape++;
Do size++ above and get rid of the variable "escape".
> +
> + size += escape;
> +
> + /*
> + * Conversion is limited to destination string max number of
> + * bytes.
> + */
> + conv_dst_size = size;
> + if (size > dst_size)
> + conv_dst_size = dst_size - 1;
> +
> + /*
> + * convert from UTF-16 unicode to ASCII
> + */
> + utf16s_to_utf8s(src, src_size, UTF16_HOST_ENDIAN, dst, conv_dst_size);
The return value is ignored.
> + dst[conv_dst_size] = 0;
> +
> + for (i = 0; i < size && i < conv_dst_size; i++) {
> + if (*src == '\\' ||
> + *src == '\r' ||
> + *src == '\n' ||
> + *src == '\t')
> + dst[i++] = '\\';
> +
> + if (*src == '\r')
> + dst[i] = 'r';
> + else if (*src == '\n')
> + dst[i] = 'n';
> + else if (*src == '\t')
> + dst[i] = 't';
> + else if (*src == '"')
> + dst[i] = '\'';
> + else
> + dst[i] = *src;
> + src++;
> + }
> +
> + *buffer = (u8 *)src;
> + *buffer_size -= size * sizeof(u16);
> +
> + return size;
> +}
> +
> +
> +/*
> + * calculate_string_buffer() - determines size of string buffer for use with BIOS communication
> + * @str: the string to calculate based upon
> + */
> +size_t bioscfg_calculate_string_buffer(const char *str)
> +{
> + int length = strlen(str);
> + int size;
> +
> + /* BIOS expects 4 bytes when an empty string is found */
> + if (!length)
> + length = 1;
> +
> + /* u16 length field + one UTF16 char for each input char */
> + size = sizeof(u16) + length * sizeof(u16);
> +
> + return size;
> +}
This full function could be:
{
/* BIOS expects 4 bytes when an empty string is found */
if (length == 0)
return 4;
/* u16 length field + one UTF16 char for each input char */
return sizeof(u16) + strlen(str) * sizeof(u16);
}
> +
> +int bioscfg_wmi_error_and_message(int error_code)
> +{
> + char *error_msg = NULL;
> + int ret;
> +
> + switch (error_code) {
> + case SUCCESS:
> + error_msg = "Success";
> + ret = 0;
> + break;
> + case CMD_FAILED:
> + error_msg = "Command failed";
> + ret = -EINVAL;
> + break;
> + case INVALID_SIGN:
> + error_msg = "Invalid signature";
> + ret = -EINVAL;
> + break;
> + case INVALID_CMD_VALUE:
> + error_msg = "Invalid command value/Feature not supported";
> + ret = -EOPNOTSUPP;
> + break;
> + case INVALID_CMD_TYPE:
> + error_msg = "Invalid command type";
> + ret = -EINVAL;
> + break;
> + case INVALID_DATA_SIZE:
> + error_msg = "Invalid data size";
> + ret = -EINVAL;
> + break;
> + case INVALID_CMD_PARAM:
> + error_msg = "Invalid command parameter";
> + ret = -EINVAL;
> + break;
> + case ENCRYP_CMD_REQUIRED:
> + error_msg = "Secure/encrypted command required";
> + ret = -EACCES;
> + break;
> + case NO_SECURE_SESSION:
> + error_msg = "No secure session established";
> + ret = -EACCES;
> + break;
> + case SECURE_SESSION_FOUND:
> + error_msg = "Secure session already established";
> + ret = -EACCES;
> + break;
> + case SECURE_SESSION_FAILED:
> + error_msg = "Secure session failed";
> + ret = -EIO;
> + break;
> + case AUTH_FAILED:
> + error_msg = "Other permission/Authentication failed";
> + ret = -EACCES;
> + break;
> + case INVALID_BIOS_AUTH:
> + error_msg = "Invalid BIOS administrator password";
> + ret = -EINVAL;
> + break;
> + case NONCE_DID_NOT_MATCH:
> + error_msg = "Nonce did not match";
> + ret = -EINVAL;
> + break;
> + case GENERIC_ERROR:
> + error_msg = "Generic/Other error";
> + ret = -EIO;
> + break;
> + case BIOS_ADMIN_POLICY_NOT_MET:
> + error_msg = "BIOS Admin password does not meet password policy requirements";
> + ret = -EINVAL;
> + break;
> + case BIOS_ADMIN_NOT_SET:
> + error_msg = "BIOS Setup password is not set.";
> + ret = -EPERM;
> + break;
> + case P21_NO_PROVISIONED:
> + error_msg = "P21 is not provisioned";
> + ret = -EPERM;
> + break;
> + case P21_PROVISION_IN_PROGRESS:
> + error_msg = "P21 is already provisioned or provisioning is in progress and a signing key has already been sent.";
> + ret = -EINPROGRESS;
> + break;
> + case P21_IN_USE:
> + error_msg = "P21 in use (cannot deprovision)";
> + ret = -EPERM;
> + break;
> + case HEP_NOT_ACTIVE:
> + error_msg = "HEP not activated";
> + ret = -EPERM;
> + break;
> + case HEP_ALREADY_SET:
> + error_msg = "HEP Transport already set";
> + ret = -EINVAL;
> + break;
> + case HEP_CHECK_STATE:
> + error_msg = "Check the current HEP state";
> + ret = -EINVAL;
> + break;
> + default:
> + error_msg = "Generic/Other error";
> + ret = -EIO;
> + break;
> + }
> +
> + if (error_code)
> + pr_warn_ratelimited("Returned error 0x%x, \"%s\"\n", error_code, error_msg);
> +
> + return ret;
> +}
> +
> +
> +/*
> + * pending_reboot_show() - sysfs implementaton for read pending_reboot
> + * @kobj: Kernel object for this attribute
> + * @attr: Kernel object attribute
> + * @buf: The buffer to display to userspace
As said before, no need to document the API of sysfs ATTR callbacks.
They are well-known.
> + *
> + * Stores default value as 0
> + * When current_value is changed this attribute is set to 1 to notify reboot may be required
> + */
> +static ssize_t pending_reboot_show(struct kobject *kobj,
> + struct kobj_attribute *attr,
> + char *buf)
> +{
> + return sysfs_emit(buf, "%d\n", bioscfg_drv.pending_reboot);
> +}
> +static struct kobj_attribute pending_reboot = __ATTR_RO(pending_reboot);
> +
> +/*
> + * create_attributes_level_sysfs_files() - Creates pending_reboot attributes
> + */
> +static int create_attributes_level_sysfs_files(void)
> +{
> + int ret;
> +
> + ret = sysfs_create_file(&bioscfg_drv.main_dir_kset->kobj, &pending_reboot.attr);
> + if (ret)
> + return ret;
> +
> + return 0;
Just:
return sysfs_create_file(&bioscfg_drv.main_dir_kset->kobj, &pending_reboot.attr);
> +}
> +
> +
> +static void attr_name_release(struct kobject *kobj)
> +{
> + kfree(kobj);
> +}
> +
> +static const struct kobj_type attr_name_ktype = {
> + .release = attr_name_release,
> + .sysfs_ops = &kobj_sysfs_ops,
> +};
> +
> +/*
> + * get_wmiobj_pointer() - Get Content of WMI block for particular instance
> + *
> + * @instance_id: WMI instance ID
> + * @guid_string: WMI GUID (in str form)
> + *
> + * Fetches the content for WMI block (instance_id) under GUID (guid_string)
> + * Caller must kfree the return
> + */
> +union acpi_object *get_wmiobj_pointer(int instance_id, const char *guid_string)
> +{
> + struct acpi_buffer out = { ACPI_ALLOCATE_BUFFER, NULL };
> + acpi_status status;
> +
> + status = wmi_query_block(guid_string, instance_id, &out);
> + return ACPI_SUCCESS(status) ? (union acpi_object *)out.pointer : NULL;
> +}
> +
> +/*
> + * get_instance_count() - Compute total number of instances under guid_string
> + *
> + * @guid_string: WMI GUID (in string form)
> + */
> +int get_instance_count(const char *guid_string)
> +{
> + union acpi_object *wmi_obj = NULL;
> + int i = 0;
> +
> + do {
> + kfree(wmi_obj);
> + wmi_obj = get_wmiobj_pointer(i, guid_string);
> + i++;
> + } while (wmi_obj);
> +
> + return i-1;
> +}
> +
> +/*
> + * alloc_attributes_data() - Allocate attributes data for a particular type
> + *
> + * @attr_type: Attribute type to allocate
> + */
> +static int alloc_attributes_data(int attr_type)
> +{
> + int retval = 0;
No need for this intermediate variable.
> +
> + switch (attr_type) {
> + case HPWMI_STRING_TYPE:
> + retval = alloc_string_data();
> + break;
> + case HPWMI_INTEGER_TYPE:
> + retval = alloc_integer_data();
> + break;
> + case HPWMI_ENUMERATION_TYPE:
> + retval = alloc_enumeration_data();
> + break;
> + case HPWMI_ORDERED_LIST_TYPE:
> + retval = alloc_ordered_list_data();
> + break;
> + case HPWMI_PASSWORD_TYPE:
> + retval = alloc_password_data();
> + break;
> + default:
> + break;
> + }
> +
> + return retval;
> +}
> +
> +int convert_hexstr_to_str(const char *input, u32 input_len, char **str, int *len)
Could this be replaced by "string_unescape(UNESCAPE_SPACE)" ?
> +{
> + int ret = 0;
> + int new_len = 0;
> + char tmp[] = "0x00";
> + char *new_str = NULL;
> + long ch;
> + int i;
> +
> + if (input_len <= 0 || input == NULL || str == NULL || len == NULL)
> + return -EINVAL;
> +
> + *len = 0;
> + *str = NULL;
> +
> + new_str = kmalloc(input_len, GFP_KERNEL);
> + if (!new_str)
> + return -ENOMEM;
> +
> + for (i = 0; i < input_len; i += 5) {
> + strncpy(tmp, input + i, strlen(tmp));
> + if (kstrtol(tmp, 16, &ch) == 0) {
> + // escape char
> + if (ch == '\\' || ch == '\r' || ch == '\n' || ch == '\t') {
> + if (ch == '\r')
> + ch = 'r';
> + else if (ch == '\n')
> + ch = 'n';
> + else if (ch == '\t')
> + ch = 't';
> + new_str[new_len++] = '\\';
> + }
> + new_str[new_len++] = ch;
> + if (ch == '\0')
> + break;
> + }
> + }
> +
> + if (new_len) {
> + new_str[new_len] = '\0';
> + *str = krealloc(new_str, (new_len + 1) * sizeof(char), GFP_KERNEL);
> + if (*str)
> + *len = new_len;
> + else
> + ret = -ENOMEM;
> + } else {
> + ret = -EFAULT;
> + }
> +
> + if (ret)
> + kfree(new_str);
> + return ret;
> +}
> +
> +/* map output size to the corresponding WMI method id */
> +int encode_outsize_for_pvsz(int outsize)
> +{
> + if (outsize > 4096)
> + return -EINVAL;
> + if (outsize > 1024)
> + return 5;
> + if (outsize > 128)
> + return 4;
> + if (outsize > 4)
> + return 3;
> + if (outsize > 0)
> + return 2;
> + return 1;
> +}
> +
> +/*
> + * Update friendly display name for several attributes associated to
> + * 'Schedule Power-On'
> + */
> +void friendly_user_name_update(char *path, const char *attr_name,
> + char *attr_display, int attr_size)
> +{
> + char *found = NULL;
No need for this variable.
> +
> + found = strstr(path, SCHEDULE_POWER_ON);
> + if (found)
> + snprintf(attr_display,
> + attr_size,
> + "%s - %s",
> + SCHEDULE_POWER_ON,
> + attr_name);
> + else
> + strscpy(attr_display, attr_name, attr_size);
> +}
> +
> +/*
> + * update_attribute_permissions() - Update attributes permissions when
> + * isReadOnly value is 1
> + *
> + * @isReadOnly: ReadOnly value
> + * @current_val: kobj_attribute corresponding to attribute.
> + *
> + */
> +void update_attribute_permissions(u32 isReadOnly, struct kobj_attribute *current_val)
> +{
> + if (isReadOnly)
> + current_val->attr.mode = (umode_t)0444;
> + else
> + current_val->attr.mode = (umode_t)0644;
No need for the casts.
isReadOnly does not use the correct naming scheme.
> +}
> +
> +
> +/**
> + * destroy_attribute_objs() - Free a kset of kobjects
> + * @kset: The kset to destroy
> + *
> + * Fress kobjects created for each attribute_name under attribute type kset
> + */
> +static void destroy_attribute_objs(struct kset *kset)
> +{
> + struct kobject *pos, *next;
> +
> + list_for_each_entry_safe(pos, next, &kset->list, entry)
> + kobject_put(pos);
> +}
> +
> +/**
> + * release_attributes_data() - Clean-up all sysfs directories and files created
> + */
> +static void release_attributes_data(void)
> +{
> + mutex_lock(&bioscfg_drv.mutex);
> +
> + exit_string_attributes();
> + exit_integer_attributes();
> + exit_enumeration_attributes();
> + exit_ordered_list_attributes();
> + exit_password_attributes();
> + exit_sure_start_attributes();
> + exit_secure_platform_attributes();
> +
> + if (bioscfg_drv.authentication_dir_kset) {
> + destroy_attribute_objs(bioscfg_drv.authentication_dir_kset);
> + kset_unregister(bioscfg_drv.authentication_dir_kset);
> + bioscfg_drv.authentication_dir_kset = NULL;
> + }
> + if (bioscfg_drv.main_dir_kset) {
> + sysfs_remove_file(&bioscfg_drv.main_dir_kset->kobj, &pending_reboot.attr);
> + destroy_attribute_objs(bioscfg_drv.main_dir_kset);
> + kset_unregister(bioscfg_drv.main_dir_kset);
> + bioscfg_drv.main_dir_kset = NULL;
> + }
> + mutex_unlock(&bioscfg_drv.mutex);
> +}
> +
> +
> +/*
> + * hp_add_other_attributes - Initialize HP custom attributes not reported by
> + * BIOS and required to support Secure Platform, Sure Start, and Sure
> + * Admin.
> + * @attr_type: Custom HP attribute not reported by BIOS
> + *
> + * Initialiaze all 3 types of attributes: Platform, Sure Start, and Sure
> + * Admin object. Populates each attrbute types respective properties
> + * under sysfs files.
Typos in this comment. checkpatch.pl can use codespell to check for
typos.
> + *
> + * Returns zero(0) if successful. Otherwise, a negative value.
> + */
> +static int hp_add_other_attributes(int attr_type)
The naming scheme is inconsistent. The prefixes "bioscfg_" and "hp_" are
used but many symbols don't use any prefix.
> +{
> + struct kobject *attr_name_kobj;
> + union acpi_object *obj = NULL;
This obj is never used except to be freed.
> + int retval = 0;
> + u8 *attr_name;
const char *
> +
> + mutex_lock(&bioscfg_drv.mutex);
> +
> + attr_name_kobj = kzalloc(sizeof(*attr_name_kobj), GFP_KERNEL);
> + if (!attr_name_kobj) {
> + retval = -ENOMEM;
> + goto err_other_attr_init;
> + }
> +
> + /* Check if attribute type is supported */
> + switch (attr_type) {
> + case HPWMI_SECURE_PLATFORM_TYPE:
> + attr_name_kobj->kset = bioscfg_drv.authentication_dir_kset;
> + attr_name = SPM_STR;
> + break;
> +
> + case HPWMI_SURE_START_TYPE:
> + attr_name_kobj->kset = bioscfg_drv.main_dir_kset;
> + attr_name = SURE_START_STR;
> + break;
> +
> + default:
> + pr_err("Error: Unknown attr_type: %d\n", attr_type);
> + retval = -EINVAL;
> + goto err_other_attr_init;
> + }
> +
> + retval = kobject_init_and_add(attr_name_kobj, &attr_name_ktype,
> + NULL, "%s", attr_name);
> + if (retval) {
> + pr_err("Error encountered [%d]\n", retval);
> + kobject_put(attr_name_kobj);
> + goto err_other_attr_init;
> + }
> +
> + /* Populate attribute data */
> + switch (attr_type) {
> + case HPWMI_SECURE_PLATFORM_TYPE:
> + retval = populate_secure_platform_data(attr_name_kobj);
> + break;
> +
> + case HPWMI_SURE_START_TYPE:
> + retval = populate_sure_start_data(attr_name_kobj);
> + break;
> +
> + default:
> + goto err_other_attr_init;
> + }
> +
> + mutex_unlock(&bioscfg_drv.mutex);
> + return 0;
> +
> +err_other_attr_init:
As mentioned before, there is no need to encode the function name into
the jump labels.
> + mutex_unlock(&bioscfg_drv.mutex);
> + kfree(obj);
> + return retval;
> +}
> +
> +/*
> + * hp_init_bios_attributes - Initialize all attributes for a type
> + * @attr_type: The attribute type to initialize
> + * @guid: The WMI GUID associated with this type to initialize
> + *
> + * Initialiaze all 5 types of attributes: enumeration, integer,
> + * string, password, ordered list object. Populates each attrbute types
> + * respective properties under sysfs files
> + */
> +static int hp_init_bios_attributes(int attr_type, const char *guid)
> +{
> + struct kobject *attr_name_kobj;
> + union acpi_object *obj = NULL;
> + union acpi_object *elements;
> + struct kset *tmp_set;
> + int min_elements;
> + char str[MAX_BUFF];
> +
> + char *temp_str = NULL;
temp_str vs tmp_set
It's using different names.
Also this does not give any indication about what it does.
Maybe "unescaped_name".
> + char *str_value = NULL;
> + int str_len;
> + int ret = 0;
> +
> + u8 *buffer_ptr = NULL;
> + int buffer_size;
> +
> +
> + /* instance_id needs to be reset for each type GUID
> + * also, instance IDs are unique within GUID but not across
> + */
> + int instance_id = 0;
> + int retval = 0;
"retval" and "ret"?
> +
> + retval = alloc_attributes_data(attr_type);
> + if (retval)
> + return retval;
> +
> + switch (attr_type) {
> + case HPWMI_STRING_TYPE:
> + min_elements = 12;
> + break;
> + case HPWMI_INTEGER_TYPE:
> + min_elements = 13;
> + break;
> + case HPWMI_ENUMERATION_TYPE:
> + min_elements = 13;
> + break;
> + case HPWMI_ORDERED_LIST_TYPE:
> + min_elements = 12;
> + break;
> + case HPWMI_PASSWORD_TYPE:
> + min_elements = 15;
> + break;
> + default:
> + pr_err("Error: Unknown attr_type: %d\n", attr_type);
> + return -EINVAL;
> + }
> +
> + /* need to use specific instance_id and guid combination to get right data */
> + obj = get_wmiobj_pointer(instance_id, guid);
> + if (!obj)
> + return -ENODEV;
> +
> + mutex_lock(&bioscfg_drv.mutex);
> + while (obj) {
> + if (obj->type != ACPI_TYPE_PACKAGE && obj->type != ACPI_TYPE_BUFFER) {
> + pr_err("Error: Expected ACPI-package or buffer type, got: %d\n", obj->type);
> + retval = -EIO;
> + goto err_attr_init;
> + }
> +
> + /* Take action appropriate to each ACPI TYPE */
> + if (obj->type == ACPI_TYPE_PACKAGE) {
> + if (obj->package.count < min_elements) {
> + pr_err("ACPI-package does not have enough elements: %d < %d\n",
> + obj->package.count, min_elements);
> + goto nextobj;
> + }
> +
> + elements = obj->package.elements;
> +
> + /* sanity checking */
> + if (elements[NAME].type != ACPI_TYPE_STRING) {
> + pr_debug("incorrect element type\n");
> + goto nextobj;
> + }
> + if (strlen(elements[NAME].string.pointer) == 0) {
> + pr_debug("empty attribute found\n");
> + goto nextobj;
> + }
> +
> + if (attr_type == HPWMI_PASSWORD_TYPE)
> + tmp_set = bioscfg_drv.authentication_dir_kset;
> + else
> + tmp_set = bioscfg_drv.main_dir_kset;
> +
> + /* convert attribute name to string */
> + retval = convert_hexstr_to_str(elements[NAME].string.pointer,
> + elements[NAME].string.length,
> + &str_value, &str_len);
> +
> + if (retval) {
> + pr_debug("Failed to populate integer package data. Error [0%0x]\n", ret);
> + kfree(str_value);
convert_hexstr_to_str should make sure that the data is freed on error
on its own.
> + return ret;
> + }
> +
> + if (kset_find_obj(tmp_set, str_value)) {
> + pr_debug("Duplicate attribute name found - %s\n",
> + str_value);
> + goto nextobj;
> + }
> +
> + /* build attribute */
> + attr_name_kobj = kzalloc(sizeof(*attr_name_kobj), GFP_KERNEL);
> + if (!attr_name_kobj) {
> + retval = -ENOMEM;
> + goto err_attr_init;
> + }
> +
> + attr_name_kobj->kset = tmp_set;
> +
> + retval = kobject_init_and_add(attr_name_kobj, &attr_name_ktype,
> + NULL, "%s", str_value);
> +
> + if (retval) {
> + kobject_put(attr_name_kobj);
The kobj was not created, why does it need the kobj_put() ?
> + goto err_attr_init;
> + }
> +
> + /* enumerate all of these attributes */
> + switch (attr_type) {
> + case HPWMI_STRING_TYPE:
> + retval = populate_string_package_data(elements,
> + instance_id,
> + attr_name_kobj);
> + break;
> + case HPWMI_INTEGER_TYPE:
> + retval = populate_integer_package_data(elements,
> + instance_id,
> + attr_name_kobj);
> + break;
> + case HPWMI_ENUMERATION_TYPE:
> + retval = populate_enumeration_package_data(elements,
> + instance_id,
> + attr_name_kobj);
> + break;
> + case HPWMI_ORDERED_LIST_TYPE:
> + retval = populate_ordered_list_package_data(elements,
> + instance_id,
> + attr_name_kobj);
> + break;
> + case HPWMI_PASSWORD_TYPE:
> + retval = populate_password_package_data(elements,
> + instance_id,
> + attr_name_kobj);
> + break;
> + default:
> + break;
This default does nothing.
> + }
> +
> + kfree(str_value);
Why is str_value only freed down here? It has not been used for half a
screen of code.
> + }
else
> +
> + if (obj->type == ACPI_TYPE_BUFFER) {
> +
> + buffer_size = obj->buffer.length;
> + buffer_ptr = obj->buffer.pointer;
> +
> + retval = get_string_from_buffer(&buffer_ptr, &buffer_size, str, MAX_BUFF);
> + if (retval < 0)
> + goto err_attr_init;
> +
> + if (attr_type == HPWMI_PASSWORD_TYPE || attr_type == HPWMI_SECURE_PLATFORM_TYPE)
> + tmp_set = bioscfg_drv.authentication_dir_kset;
> + else
> + tmp_set = bioscfg_drv.main_dir_kset;
There is a bunch of common logic duplicated in both the buffer and
package branches.
> +
> + if (kset_find_obj(tmp_set, str)) {
> + pr_warn("Duplicate attribute name found - %s\n", str);
Also mention that it is being ignored.
> + goto nextobj;
> + }
> +
> + /* build attribute */
> + attr_name_kobj = kzalloc(sizeof(*attr_name_kobj), GFP_KERNEL);
> + if (!attr_name_kobj) {
> + retval = -ENOMEM;
> + goto err_attr_init;
> + }
> +
> + attr_name_kobj->kset = tmp_set;
> +
> + temp_str = str;
> + if (attr_type == HPWMI_SECURE_PLATFORM_TYPE)
> + temp_str = "SPM";
> +
> + retval = kobject_init_and_add(attr_name_kobj,
> + &attr_name_ktype, NULL, "%s",
> + temp_str);
> + if (retval) {
> + kobject_put(attr_name_kobj);
> + goto err_attr_init;
> + }
> +
> + /* enumerate all of these attributes */
> + switch (attr_type) {
> + case HPWMI_STRING_TYPE:
> + retval = populate_string_buffer_data(buffer_ptr,
> + &buffer_size,
> + instance_id,
> + attr_name_kobj);
> + break;
> + case HPWMI_INTEGER_TYPE:
> + retval = populate_integer_buffer_data(buffer_ptr,
> + &buffer_size,
> + instance_id,
> + attr_name_kobj);
> + break;
> + case HPWMI_ENUMERATION_TYPE:
> + retval = populate_enumeration_buffer_data(buffer_ptr,
> + &buffer_size,
> + instance_id,
> + attr_name_kobj);
> + break;
> + case HPWMI_ORDERED_LIST_TYPE:
> + retval = populate_ordered_list_buffer_data(buffer_ptr,
> + &buffer_size,
> + instance_id,
> + attr_name_kobj);
> + break;
> + case HPWMI_PASSWORD_TYPE:
> + retval = populate_password_buffer_data(buffer_ptr,
> + &buffer_size,
> + instance_id,
> + attr_name_kobj);
> + break;
> + default:
> + break;
> + }
> + }
What if it's neither a package nor a buffer?
> +nextobj:
> + kfree(str_value);
> + kfree(obj);
> + instance_id++;
> + obj = get_wmiobj_pointer(instance_id, guid);
> + }
> + mutex_unlock(&bioscfg_drv.mutex);
> + return 0;
> +
> +err_attr_init:
This can leak str_value.
> + mutex_unlock(&bioscfg_drv.mutex);
> + kfree(obj);
> + return retval;
> +}
This function *really* needs to split up.
> +
> +static int __init bioscfg_init(void)
> +{
> + int ret = 0;
No need to initialize.
> + int bios_capable = wmi_has_guid(HP_WMI_BIOS_GUID);
> +
> + if (!bios_capable) {
> + pr_err("Unable to run on non-HP system\n");
> + return -ENODEV;
> + }
> +
> + ret = init_bios_attr_set_interface();
> + if (ret)
> + return ret;
> +
> + ret = init_bios_attr_pass_interface();
> + if (ret)
> + goto err_exit_bios_attr_set_interface;
> +
> + if (!bioscfg_drv.bios_attr_wdev || !bioscfg_drv.password_attr_wdev) {
> + pr_debug("Failed to find set or pass interface\n");
> + ret = -ENODEV;
> + goto err_exit_bios_attr_pass_interface;
> + }
Can this ever happen?
> +
> + ret = fw_attributes_class_get(&fw_attr_class);
> + if (ret)
> + goto err_exit_bios_attr_pass_interface;
> +
> + bioscfg_drv.class_dev = device_create(fw_attr_class, NULL, MKDEV(0, 0),
> + NULL, "%s", DRIVER_NAME);
> + if (IS_ERR(bioscfg_drv.class_dev)) {
> + ret = PTR_ERR(bioscfg_drv.class_dev);
> + goto err_unregister_class;
> + }
> +
> + bioscfg_drv.main_dir_kset = kset_create_and_add("attributes", NULL,
> + &bioscfg_drv.class_dev->kobj);
> + if (!bioscfg_drv.main_dir_kset) {
> + ret = -ENOMEM;
> + pr_debug("Failed to create and add attributes\n");
> + goto err_destroy_classdev;
> + }
> +
> + bioscfg_drv.authentication_dir_kset = kset_create_and_add("authentication", NULL,
> + &bioscfg_drv.class_dev->kobj);
> + if (!bioscfg_drv.authentication_dir_kset) {
> + ret = -ENOMEM;
> + pr_debug("Failed to create and add authentication\n");
> + goto err_release_attributes_data;
> + }
> +
> + /*
> + * sysfs level attributes.
> + * - pending_reboot
> + */
> + ret = create_attributes_level_sysfs_files();
> + if (ret)
> + pr_debug("Failed to create sysfs level attributes\n");
Why continue when these fail?
> + ret = hp_init_bios_attributes(HPWMI_STRING_TYPE, HP_WMI_BIOS_STRING_GUID);
> + if (ret)
> + pr_debug("Failed to populate string type attributes\n");
> +
> + ret = hp_init_bios_attributes(HPWMI_INTEGER_TYPE, HP_WMI_BIOS_INTEGER_GUID);
> + if (ret)
> + pr_debug("Failed to populate integer type attributes\n");
> +
> + ret = hp_init_bios_attributes(HPWMI_ENUMERATION_TYPE, HP_WMI_BIOS_ENUMERATION_GUID);
> + if (ret)
> + pr_debug("Failed to populate enumeration type attributes\n");
> +
> + ret = hp_init_bios_attributes(HPWMI_ORDERED_LIST_TYPE, HP_WMI_BIOS_ORDERED_LIST_GUID);
> + if (ret)
> + pr_debug("Failed to populate ordered list object type attributes\n");
> +
> + ret = hp_init_bios_attributes(HPWMI_PASSWORD_TYPE, HP_WMI_BIOS_PASSWORD_GUID);
> + if (ret)
> + pr_debug("Failed to populate password object type attributes\n");
> +
> + bioscfg_drv.spm_data.attr_name_kobj = NULL;
> + ret = hp_add_other_attributes(HPWMI_SECURE_PLATFORM_TYPE);
> + if (ret)
> + pr_debug("Failed to populate secure platform object type attribute\n");
> +
> + bioscfg_drv.sure_start_attr_kobj = NULL;
> + ret = hp_add_other_attributes(HPWMI_SURE_START_TYPE);
> + if (ret)
> + pr_debug("Failed to populate sure start object type attribute\n");
> +
> + return 0;
> +
> +err_release_attributes_data:
> + release_attributes_data();
> +
> +err_destroy_classdev:
> + device_destroy(fw_attr_class, MKDEV(0, 0));
> +
> +err_unregister_class:
> + fw_attributes_class_put();
> +
> +err_exit_bios_attr_pass_interface:
> + exit_bios_attr_pass_interface();
> +
> +err_exit_bios_attr_set_interface:
> + exit_bios_attr_set_interface();
> +
> + return ret;
> +}
> +
> +static void __exit bioscfg_exit(void)
> +{
> + release_attributes_data();
> + device_destroy(fw_attr_class, MKDEV(0, 0));
> +
> + fw_attributes_class_put();
> + exit_bios_attr_set_interface();
> + exit_bios_attr_pass_interface();
> +}
> +
> +module_init(bioscfg_init);
> +module_exit(bioscfg_exit);
> --
> 2.34.1
>
On Sat, Apr 22, 2023 at 5:16 PM <thomas@t-8ch.de> wrote:
>
> On 2023-04-20 11:54:43-0500, Jorge Lopez wrote:
> > ---
> > drivers/platform/x86/hp/hp-bioscfg/bioscfg.c | 961 +++++++++++++++++++
> > 1 file changed, 961 insertions(+)
> > create mode 100644 drivers/platform/x86/hp/hp-bioscfg/bioscfg.c
> >
> > diff --git a/drivers/platform/x86/hp/hp-bioscfg/bioscfg.c b/drivers/platform/x86/hp/hp-bioscfg/bioscfg.c
> > new file mode 100644
> > index 000000000000..4b0d4f56e65f
> > --- /dev/null
> > +++ b/drivers/platform/x86/hp/hp-bioscfg/bioscfg.c
> > @@ -0,0 +1,961 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * Common methods for use with hp-bioscfg driver
> > + *
> > + * Copyright (c) 2022 HP Development Company, L.P.
> > + */
> > +
> > +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
> > +
> > +#include <linux/fs.h>
> > +#include <linux/module.h>
> > +#include <linux/kernel.h>
> > +#include <linux/wmi.h>
> > +#include "bioscfg.h"
> > +#include "../../firmware_attributes_class.h"
> > +#include <linux/nls.h>
> > +#include <linux/errno.h>
> > +
> > +MODULE_AUTHOR("Jorge Lopez <jorge.lopez2@hp.com>");
> > +MODULE_DESCRIPTION("HP BIOS Configuration Driver");
> > +MODULE_LICENSE("GPL");
> > +
> > +struct bioscfg_priv bioscfg_drv = {
> > + .mutex = __MUTEX_INITIALIZER(bioscfg_drv.mutex),
> > +};
> > +
> > +static struct class *fw_attr_class;
> > +
> > +int get_integer_from_buffer(int **buffer, u32 *buffer_size, int *integer)
> > +{
>
> It would be clearer to use u32 or s32 instead of int/integer.
>
> This should also take a "u8 **buffer" to avoid casts in all the callers.
Done!
>
> > + int *ptr = PTR_ALIGN(*buffer, 4);
> > +
> > + /* Ensure there is enough space remaining to read the integer */
> > + if (*buffer_size < sizeof(int))
> > + return -EINVAL;
> > +
> > + *integer = *(ptr++);
> > + *buffer = ptr;
> > + *buffer_size -= sizeof(int);
> > +
> > + return 0;
> > +}
> > +
> > +
> > +int get_string_from_buffer(u8 **buffer, u32 *buffer_size, char *dst, u32 dst_size)
> > +{
> > + u16 *src = (u16 *)*buffer;
> > + u16 src_size;
> > +
> > + u16 size;
> > + int i;
> > + int escape = 0;
> > + int conv_dst_size;
> > +
> > + if (*buffer_size < sizeof(u16))
> > + return -EINVAL;
> > +
> > + src_size = *(src++);
> > + /* size value in u16 chars */
> > + size = src_size / sizeof(u16);
> > +
> > + /* Ensure there is enough space remaining to read and convert
> > + * the string
> > + */
> > + if (*buffer_size < src_size)
> > + return -EINVAL;
> > +
> > + for (i = 0; i < size; i++)
> > + if (src[i] == '\\' ||
> > + src[i] == '\r' ||
> > + src[i] == '\n' ||
> > + src[i] == '\t')
> > + escape++;
>
> Do size++ above and get rid of the variable "escape".
Done!
>
> > +
> > + size += escape;
> > +
> > + /*
> > + * Conversion is limited to destination string max number of
> > + * bytes.
> > + */
> > + conv_dst_size = size;
> > + if (size > dst_size)
> > + conv_dst_size = dst_size - 1;
> > +
> > + /*
> > + * convert from UTF-16 unicode to ASCII
> > + */
> > + utf16s_to_utf8s(src, src_size, UTF16_HOST_ENDIAN, dst, conv_dst_size);
>
> The return value is ignored.
>
> > + dst[conv_dst_size] = 0;
> > +
> > + for (i = 0; i < size && i < conv_dst_size; i++) {
> > + if (*src == '\\' ||
> > + *src == '\r' ||
> > + *src == '\n' ||
> > + *src == '\t')
> > + dst[i++] = '\\';
> > +
> > + if (*src == '\r')
> > + dst[i] = 'r';
> > + else if (*src == '\n')
> > + dst[i] = 'n';
> > + else if (*src == '\t')
> > + dst[i] = 't';
> > + else if (*src == '"')
> > + dst[i] = '\'';
> > + else
> > + dst[i] = *src;
> > + src++;
> > + }
> > +
> > + *buffer = (u8 *)src;
> > + *buffer_size -= size * sizeof(u16);
> > +
> > + return size;
> > +}
> > +
> > +
> > +/*
> > + * calculate_string_buffer() - determines size of string buffer for use with BIOS communication
> > + * @str: the string to calculate based upon
> > + */
> > +size_t bioscfg_calculate_string_buffer(const char *str)
> > +{
> > + int length = strlen(str);
> > + int size;
> > +
> > + /* BIOS expects 4 bytes when an empty string is found */
> > + if (!length)
> > + length = 1;
> > +
> > + /* u16 length field + one UTF16 char for each input char */
> > + size = sizeof(u16) + length * sizeof(u16);
> > +
> > + return size;
> > +}
>
> This full function could be:
>
> {
> /* BIOS expects 4 bytes when an empty string is found */
> if (length == 0)
> return 4;
>
> /* u16 length field + one UTF16 char for each input char */
> return sizeof(u16) + strlen(str) * sizeof(u16);
> }
>
Done!
<snip>
> > +
> > +/*
> > + * pending_reboot_show() - sysfs implementaton for read pending_reboot
> > + * @kobj: Kernel object for this attribute
> > + * @attr: Kernel object attribute
> > + * @buf: The buffer to display to userspace
>
> As said before, no need to document the API of sysfs ATTR callbacks.
> They are well-known.
>
Done across all files.
> > + *
> > + * Stores default value as 0
> > + * When current_value is changed this attribute is set to 1 to notify reboot may be required
> > + */
> > +static ssize_t pending_reboot_show(struct kobject *kobj,
> > + struct kobj_attribute *attr,
> > + char *buf)
> > +{
> > + return sysfs_emit(buf, "%d\n", bioscfg_drv.pending_reboot);
> > +}
> > +static struct kobj_attribute pending_reboot = __ATTR_RO(pending_reboot);
> > +
> > +/*
> > + * create_attributes_level_sysfs_files() - Creates pending_reboot attributes
> > + */
> > +static int create_attributes_level_sysfs_files(void)
> > +{
> > + int ret;
> > +
> > + ret = sysfs_create_file(&bioscfg_drv.main_dir_kset->kobj, &pending_reboot.attr);
> > + if (ret)
> > + return ret;
> > +
> > + return 0;
>
> Just:
> return sysfs_create_file(&bioscfg_drv.main_dir_kset->kobj, &pending_reboot.attr);
Done!
>
> > +}
> > +
> > +
<snip>
> > +
> > +/*
> > + * alloc_attributes_data() - Allocate attributes data for a particular type
> > + *
> > + * @attr_type: Attribute type to allocate
> > + */
> > +static int alloc_attributes_data(int attr_type)
> > +{
> > + int retval = 0;
>
> No need for this intermediate variable.
>
> > +
> > + switch (attr_type) {
> > + case HPWMI_STRING_TYPE:
> > + retval = alloc_string_data();
> > + break;
> > + case HPWMI_INTEGER_TYPE:
> > + retval = alloc_integer_data();
> > + break;
> > + case HPWMI_ENUMERATION_TYPE:
> > + retval = alloc_enumeration_data();
> > + break;
> > + case HPWMI_ORDERED_LIST_TYPE:
> > + retval = alloc_ordered_list_data();
> > + break;
> > + case HPWMI_PASSWORD_TYPE:
> > + retval = alloc_password_data();
> > + break;
> > + default:
> > + break;
> > + }
> > +
> > + return retval;
> > +}
> > +
Done!
> > +int convert_hexstr_to_str(const char *input, u32 input_len, char **str, int *len)
>
> Could this be replaced by "string_unescape(UNESCAPE_SPACE)" ?
>
> > +{
> > + int ret = 0;
> > + int new_len = 0;
> > + char tmp[] = "0x00";
> > + char *new_str = NULL;
> > + long ch;
> > + int i;
> > +
> > + if (input_len <= 0 || input == NULL || str == NULL || len == NULL)
> > + return -EINVAL;
> > +
> > + *len = 0;
> > + *str = NULL;
> > +
> > + new_str = kmalloc(input_len, GFP_KERNEL);
> > + if (!new_str)
> > + return -ENOMEM;
> > +
> > + for (i = 0; i < input_len; i += 5) {
> > + strncpy(tmp, input + i, strlen(tmp));
> > + if (kstrtol(tmp, 16, &ch) == 0) {
> > + // escape char
> > + if (ch == '\\' || ch == '\r' || ch == '\n' || ch == '\t') {
> > + if (ch == '\r')
> > + ch = 'r';
> > + else if (ch == '\n')
> > + ch = 'n';
> > + else if (ch == '\t')
> > + ch = 't';
> > + new_str[new_len++] = '\\';
> > + }
> > + new_str[new_len++] = ch;
> > + if (ch == '\0')
> > + break;
> > + }
> > + }
> > +
> > + if (new_len) {
> > + new_str[new_len] = '\0';
> > + *str = krealloc(new_str, (new_len + 1) * sizeof(char), GFP_KERNEL);
> > + if (*str)
> > + *len = new_len;
> > + else
> > + ret = -ENOMEM;
> > + } else {
> > + ret = -EFAULT;
> > + }
> > +
> > + if (ret)
> > + kfree(new_str);
> > + return ret;
> > +}
> > +
> > +/* map output size to the corresponding WMI method id */
> > +int encode_outsize_for_pvsz(int outsize)
> > +{
> > + if (outsize > 4096)
> > + return -EINVAL;
> > + if (outsize > 1024)
> > + return 5;
> > + if (outsize > 128)
> > + return 4;
> > + if (outsize > 4)
> > + return 3;
> > + if (outsize > 0)
> > + return 2;
> > + return 1;
> > +}
> > +
> > +/*
> > + * Update friendly display name for several attributes associated to
> > + * 'Schedule Power-On'
> > + */
> > +void friendly_user_name_update(char *path, const char *attr_name,
> > + char *attr_display, int attr_size)
> > +{
> > + char *found = NULL;
>
> No need for this variable.
Done!
>
> > +
> > + found = strstr(path, SCHEDULE_POWER_ON);
> > + if (found)
> > + snprintf(attr_display,
> > + attr_size,
> > + "%s - %s",
> > + SCHEDULE_POWER_ON,
> > + attr_name);
> > + else
> > + strscpy(attr_display, attr_name, attr_size);
> > +}
> > +
> > +/*
> > + * update_attribute_permissions() - Update attributes permissions when
> > + * isReadOnly value is 1
> > + *
> > + * @isReadOnly: ReadOnly value
> > + * @current_val: kobj_attribute corresponding to attribute.
> > + *
> > + */
> > +void update_attribute_permissions(u32 isReadOnly, struct kobj_attribute *current_val)
> > +{
> > + if (isReadOnly)
> > + current_val->attr.mode = (umode_t)0444;
> > + else
> > + current_val->attr.mode = (umode_t)0644;
>
> No need for the casts.
>
> isReadOnly does not use the correct naming scheme.
>
Done!
> > +}
> > +
<snip>
> > + * hp_add_other_attributes - Initialize HP custom attributes not reported by
> > + * BIOS and required to support Secure Platform, Sure Start, and Sure
> > + * Admin.
> > + * @attr_type: Custom HP attribute not reported by BIOS
> > + *
> > + * Initialiaze all 3 types of attributes: Platform, Sure Start, and Sure
> > + * Admin object. Populates each attrbute types respective properties
> > + * under sysfs files.
>
> Typos in this comment. checkpatch.pl can use codespell to check for
> typos.
>
Done!
> > + *
> > + * Returns zero(0) if successful. Otherwise, a negative value.
> > + */
> > +static int hp_add_other_attributes(int attr_type)
>
> The naming scheme is inconsistent. The prefixes "bioscfg_" and "hp_" are
> used but many symbols don't use any prefix.
Done! Prefixes set to bioscfg_ for all functions.
>
> > +{
> > + struct kobject *attr_name_kobj;
> > + union acpi_object *obj = NULL;
>
> This obj is never used except to be freed.
>
> > + int retval = 0;
> > + u8 *attr_name;
>
> const char *
Cannot define attr_name as 'const char *'. attr_name value is set
within the function
>
> > +
> > + mutex_lock(&bioscfg_drv.mutex);
> > +
> > + attr_name_kobj = kzalloc(sizeof(*attr_name_kobj), GFP_KERNEL);
> > + if (!attr_name_kobj) {
> > + retval = -ENOMEM;
> > + goto err_other_attr_init;
> > + }
> > +
> > + /* Check if attribute type is supported */
> > + switch (attr_type) {
> > + case HPWMI_SECURE_PLATFORM_TYPE:
> > + attr_name_kobj->kset = bioscfg_drv.authentication_dir_kset;
> > + attr_name = SPM_STR;
> > + break;
> > +
> > + case HPWMI_SURE_START_TYPE:
> > + attr_name_kobj->kset = bioscfg_drv.main_dir_kset;
> > + attr_name = SURE_START_STR;
> > + break;
> > +
> > + default:
> > + pr_err("Error: Unknown attr_type: %d\n", attr_type);
> > + retval = -EINVAL;
> > + goto err_other_attr_init;
> > + }
> > +
> > + retval = kobject_init_and_add(attr_name_kobj, &attr_name_ktype,
> > + NULL, "%s", attr_name);
> > + if (retval) {
> > + pr_err("Error encountered [%d]\n", retval);
> > + kobject_put(attr_name_kobj);
> > + goto err_other_attr_init;
> > + }
> > +
> > + /* Populate attribute data */
> > + switch (attr_type) {
> > + case HPWMI_SECURE_PLATFORM_TYPE:
> > + retval = populate_secure_platform_data(attr_name_kobj);
> > + break;
> > +
> > + case HPWMI_SURE_START_TYPE:
> > + retval = populate_sure_start_data(attr_name_kobj);
> > + break;
> > +
> > + default:
> > + goto err_other_attr_init;
> > + }
> > +
> > + mutex_unlock(&bioscfg_drv.mutex);
> > + return 0;
> > +
> > +err_other_attr_init:
>
> As mentioned before, there is no need to encode the function name into
> the jump labels.
>
Done across all files
> > + mutex_unlock(&bioscfg_drv.mutex);
> > + kfree(obj);
> > + return retval;
> > +}
> > +
> > +/*
> > + * hp_init_bios_attributes - Initialize all attributes for a type
> > + * @attr_type: The attribute type to initialize
> > + * @guid: The WMI GUID associated with this type to initialize
> > + *
> > + * Initialiaze all 5 types of attributes: enumeration, integer,
> > + * string, password, ordered list object. Populates each attrbute types
> > + * respective properties under sysfs files
> > + */
> > +static int hp_init_bios_attributes(int attr_type, const char *guid)
> > +{
> > + struct kobject *attr_name_kobj;
> > + union acpi_object *obj = NULL;
> > + union acpi_object *elements;
> > + struct kset *tmp_set;
> > + int min_elements;
> > + char str[MAX_BUFF];
> > +
> > + char *temp_str = NULL;
>
> temp_str vs tmp_set
>
> It's using different names.
>
> Also this does not give any indication about what it does.
>
> Maybe "unescaped_name".
tmp_set name is incomplete. It should read temp_kset. The correct
name will clearly differentiate temp_str from temp_kset.
>
> > + char *str_value = NULL;
> > + int str_len;
> > + int ret = 0;
> > +
> > + u8 *buffer_ptr = NULL;
> > + int buffer_size;
> > +
> > +
> > + /* instance_id needs to be reset for each type GUID
> > + * also, instance IDs are unique within GUID but not across
> > + */
> > + int instance_id = 0;
> > + int retval = 0;
>
> "retval" and "ret"?
Only retval should be present.
Done!
>
> > +
> > + retval = alloc_attributes_data(attr_type);
> > + if (retval)
> > + return retval;
> > +
> > + switch (attr_type) {
> > + case HPWMI_STRING_TYPE:
> > + min_elements = 12;
> > + break;
> > + case HPWMI_INTEGER_TYPE:
> > + min_elements = 13;
> > + break;
> > + case HPWMI_ENUMERATION_TYPE:
> > + min_elements = 13;
> > + break;
> > + case HPWMI_ORDERED_LIST_TYPE:
> > + min_elements = 12;
> > + break;
> > + case HPWMI_PASSWORD_TYPE:
> > + min_elements = 15;
> > + break;
> > + default:
> > + pr_err("Error: Unknown attr_type: %d\n", attr_type);
> > + return -EINVAL;
> > + }
> > +
> > + /* need to use specific instance_id and guid combination to get right data */
> > + obj = get_wmiobj_pointer(instance_id, guid);
> > + if (!obj)
> > + return -ENODEV;
> > +
> > + mutex_lock(&bioscfg_drv.mutex);
> > + while (obj) {
> > + if (obj->type != ACPI_TYPE_PACKAGE && obj->type != ACPI_TYPE_BUFFER) {
> > + pr_err("Error: Expected ACPI-package or buffer type, got: %d\n", obj->type);
> > + retval = -EIO;
> > + goto err_attr_init;
> > + }
> > +
> > + /* Take action appropriate to each ACPI TYPE */
> > + if (obj->type == ACPI_TYPE_PACKAGE) {
> > + if (obj->package.count < min_elements) {
> > + pr_err("ACPI-package does not have enough elements: %d < %d\n",
> > + obj->package.count, min_elements);
> > + goto nextobj;
> > + }
> > +
> > + elements = obj->package.elements;
> > +
> > + /* sanity checking */
> > + if (elements[NAME].type != ACPI_TYPE_STRING) {
> > + pr_debug("incorrect element type\n");
> > + goto nextobj;
> > + }
> > + if (strlen(elements[NAME].string.pointer) == 0) {
> > + pr_debug("empty attribute found\n");
> > + goto nextobj;
> > + }
> > +
> > + if (attr_type == HPWMI_PASSWORD_TYPE)
> > + tmp_set = bioscfg_drv.authentication_dir_kset;
> > + else
> > + tmp_set = bioscfg_drv.main_dir_kset;
> > +
> > + /* convert attribute name to string */
> > + retval = convert_hexstr_to_str(elements[NAME].string.pointer,
> > + elements[NAME].string.length,
> > + &str_value, &str_len);
> > +
> > + if (retval) {
> > + pr_debug("Failed to populate integer package data. Error [0%0x]\n", ret);
> > + kfree(str_value);
>
> convert_hexstr_to_str should make sure that the data is freed on error
> on its own.
Confirmed the allocated data is freed by convert_hexstr_to_str clears
on error on its own.
>
> > + return ret;
> > + }
> > +
> > + if (kset_find_obj(tmp_set, str_value)) {
> > + pr_debug("Duplicate attribute name found - %s\n",
> > + str_value);
> > + goto nextobj;
> > + }
> > +
> > + /* build attribute */
> > + attr_name_kobj = kzalloc(sizeof(*attr_name_kobj), GFP_KERNEL);
> > + if (!attr_name_kobj) {
> > + retval = -ENOMEM;
> > + goto err_attr_init;
> > + }
> > +
> > + attr_name_kobj->kset = tmp_set;
> > +
> > + retval = kobject_init_and_add(attr_name_kobj, &attr_name_ktype,
> > + NULL, "%s", str_value);
> > +
> > + if (retval) {
> > + kobject_put(attr_name_kobj);
>
> The kobj was not created, why does it need the kobj_put() ?
As indicated by kobject_init_and_add ...
* This function combines the call to kobject_init() and kobject_add().
*
* If this function returns an error, kobject_put() must be called to
* properly clean up the memory associated with the object. This is the
* same type of error handling after a call to kobject_add() and kobject
* lifetime rules are the same here.
>
> > + goto err_attr_init;
> > + }
> > +
> > + /* enumerate all of these attributes */
> > + switch (attr_type) {
> > + case HPWMI_STRING_TYPE:
> > + retval = populate_string_package_data(elements,
> > + instance_id,
> > + attr_name_kobj);
> > + break;
> > + case HPWMI_INTEGER_TYPE:
> > + retval = populate_integer_package_data(elements,
> > + instance_id,
> > + attr_name_kobj);
> > + break;
> > + case HPWMI_ENUMERATION_TYPE:
> > + retval = populate_enumeration_package_data(elements,
> > + instance_id,
> > + attr_name_kobj);
> > + break;
> > + case HPWMI_ORDERED_LIST_TYPE:
> > + retval = populate_ordered_list_package_data(elements,
> > + instance_id,
> > + attr_name_kobj);
> > + break;
> > + case HPWMI_PASSWORD_TYPE:
> > + retval = populate_password_package_data(elements,
> > + instance_id,
> > + attr_name_kobj);
> > + break;
> > + default:
> > + break;
>
> This default does nothing.
>
> > + }
> > +
> > + kfree(str_value);
>
> Why is str_value only freed down here? It has not been used for half a
> screen of code.
Added early in the development process and failed to clean up here.
>
> > + }
>
> else
>
> > +
> > + if (obj->type == ACPI_TYPE_BUFFER) {
> > +
> > + buffer_size = obj->buffer.length;
> > + buffer_ptr = obj->buffer.pointer;
> > +
> > + retval = get_string_from_buffer(&buffer_ptr, &buffer_size, str, MAX_BUFF);
> > + if (retval < 0)
> > + goto err_attr_init;
> > +
> > + if (attr_type == HPWMI_PASSWORD_TYPE || attr_type == HPWMI_SECURE_PLATFORM_TYPE)
> > + tmp_set = bioscfg_drv.authentication_dir_kset;
> > + else
> > + tmp_set = bioscfg_drv.main_dir_kset;
>
> There is a bunch of common logic duplicated in both the buffer and
> package branches.
Older BIOS reports the ACPI data as objects of type ACPI_TYPE_PACKAGE
and the associated data is reported as elements.
Newer BIOS reports the ACPI data as objects of type ACPI_TYPE_BUFFER.
(actypes.h union acpi_object)
The code follows a common logic although the data is acquired
differently according to the ACPI object type
>
> > +
> > + if (kset_find_obj(tmp_set, str)) {
> > + pr_warn("Duplicate attribute name found - %s\n", str);
>
> Also mention that it is being ignored.
>
> > + goto nextobj;
> > + }
> > +
> > + /* build attribute */
> > + attr_name_kobj = kzalloc(sizeof(*attr_name_kobj), GFP_KERNEL);
> > + if (!attr_name_kobj) {
> > + retval = -ENOMEM;
> > + goto err_attr_init;
> > + }
> > +
> > + attr_name_kobj->kset = tmp_set;
> > +
> > + temp_str = str;
> > + if (attr_type == HPWMI_SECURE_PLATFORM_TYPE)
> > + temp_str = "SPM";
> > +
> > + retval = kobject_init_and_add(attr_name_kobj,
> > + &attr_name_ktype, NULL, "%s",
> > + temp_str);
> > + if (retval) {
> > + kobject_put(attr_name_kobj);
> > + goto err_attr_init;
> > + }
> > +
> > + /* enumerate all of these attributes */
> > + switch (attr_type) {
> > + case HPWMI_STRING_TYPE:
> > + retval = populate_string_buffer_data(buffer_ptr,
> > + &buffer_size,
> > + instance_id,
> > + attr_name_kobj);
> > + break;
> > + case HPWMI_INTEGER_TYPE:
> > + retval = populate_integer_buffer_data(buffer_ptr,
> > + &buffer_size,
> > + instance_id,
> > + attr_name_kobj);
> > + break;
> > + case HPWMI_ENUMERATION_TYPE:
> > + retval = populate_enumeration_buffer_data(buffer_ptr,
> > + &buffer_size,
> > + instance_id,
> > + attr_name_kobj);
> > + break;
> > + case HPWMI_ORDERED_LIST_TYPE:
> > + retval = populate_ordered_list_buffer_data(buffer_ptr,
> > + &buffer_size,
> > + instance_id,
> > + attr_name_kobj);
> > + break;
> > + case HPWMI_PASSWORD_TYPE:
> > + retval = populate_password_buffer_data(buffer_ptr,
> > + &buffer_size,
> > + instance_id,
> > + attr_name_kobj);
> > + break;
> > + default:
> > + break;
> > + }
> > + }
>
> What if it's neither a package nor a buffer?
we return an error if it is neither a package nor a buffer.
if (obj->type != ACPI_TYPE_PACKAGE && obj->type != ACPI_TYPE_BUFFER) {
pr_err("Error: Expected ACPI-package or buffer type, got:
%d\n", obj->type);
retval = -EIO;
goto err_attr_init;
}
>
> > +nextobj:
> > + kfree(str_value);
> > + kfree(obj);
> > + instance_id++;
> > + obj = get_wmiobj_pointer(instance_id, guid);
> > + }
> > + mutex_unlock(&bioscfg_drv.mutex);
> > + return 0;
> > +
> > +err_attr_init:
>
> This can leak str_value.
Done!
>
> > + mutex_unlock(&bioscfg_drv.mutex);
> > + kfree(obj);
> > + return retval;
> > +}
>
> This function *really* needs to split up.
Done! function hp_init_bios_attributes() will split into two;
package and buffer objects.
>
> > +
> > +static int __init bioscfg_init(void)
> > +{
> > + int ret = 0;
>
> No need to initialize.
Done!
>
> > + int bios_capable = wmi_has_guid(HP_WMI_BIOS_GUID);
> > +
> > + if (!bios_capable) {
> > + pr_err("Unable to run on non-HP system\n");
> > + return -ENODEV;
> > + }
> > +
> > + ret = init_bios_attr_set_interface();
> > + if (ret)
> > + return ret;
> > +
> > + ret = init_bios_attr_pass_interface();
> > + if (ret)
> > + goto err_exit_bios_attr_set_interface;
> > +
> > + if (!bioscfg_drv.bios_attr_wdev || !bioscfg_drv.password_attr_wdev) {
> > + pr_debug("Failed to find set or pass interface\n");
> > + ret = -ENODEV;
> > + goto err_exit_bios_attr_pass_interface;
> > + }
>
> Can this ever happen?
The initial steps prior to this piece of code have changed. This code
is no longer needed nor condition will occur.
>
> > +
> > + ret = fw_attributes_class_get(&fw_attr_class);
> > + if (ret)
> > + goto err_exit_bios_attr_pass_interface;
> > +
> > + bioscfg_drv.class_dev = device_create(fw_attr_class, NULL, MKDEV(0, 0),
> > + NULL, "%s", DRIVER_NAME);
> > + if (IS_ERR(bioscfg_drv.class_dev)) {
> > + ret = PTR_ERR(bioscfg_drv.class_dev);
> > + goto err_unregister_class;
> > + }
> > +
> > + bioscfg_drv.main_dir_kset = kset_create_and_add("attributes", NULL,
> > + &bioscfg_drv.class_dev->kobj);
> > + if (!bioscfg_drv.main_dir_kset) {
> > + ret = -ENOMEM;
> > + pr_debug("Failed to create and add attributes\n");
> > + goto err_destroy_classdev;
> > + }
> > +
> > + bioscfg_drv.authentication_dir_kset = kset_create_and_add("authentication", NULL,
> > + &bioscfg_drv.class_dev->kobj);
> > + if (!bioscfg_drv.authentication_dir_kset) {
> > + ret = -ENOMEM;
> > + pr_debug("Failed to create and add authentication\n");
> > + goto err_release_attributes_data;
> > + }
> > +
> > + /*
> > + * sysfs level attributes.
> > + * - pending_reboot
> > + */
> > + ret = create_attributes_level_sysfs_files();
> > + if (ret)
> > + pr_debug("Failed to create sysfs level attributes\n");
>
> Why continue when these fail?
The failures will be documented but will not stop the driver from
searching for other attributes and adding them.
BIOS could easily remove attributes associated with
HP_WMI_BIOS_INTEGER_GUID. In that case, the driver will report
INTEGER attributes were not populated and allows the driver to
continue loading.
>
> > + ret = hp_init_bios_attributes(HPWMI_STRING_TYPE, HP_WMI_BIOS_STRING_GUID);
> > + if (ret)
> > + pr_debug("Failed to populate string type attributes\n");
> > +
> > + ret = hp_init_bios_attributes(HPWMI_INTEGER_TYPE, HP_WMI_BIOS_INTEGER_GUID);
> > + if (ret)
> > + pr_debug("Failed to populate integer type attributes\n");
> > +
> > + ret = hp_init_bios_attributes(HPWMI_ENUMERATION_TYPE, HP_WMI_BIOS_ENUMERATION_GUID);
> > + if (ret)
> > + pr_debug("Failed to populate enumeration type attributes\n");
> > +
> > + ret = hp_init_bios_attributes(HPWMI_ORDERED_LIST_TYPE, HP_WMI_BIOS_ORDERED_LIST_GUID);
> > + if (ret)
> > + pr_debug("Failed to populate ordered list object type attributes\n");
> > +
> > + ret = hp_init_bios_attributes(HPWMI_PASSWORD_TYPE, HP_WMI_BIOS_PASSWORD_GUID);
> > + if (ret)
> > + pr_debug("Failed to populate password object type attributes\n");
> > +
> > + bioscfg_drv.spm_data.attr_name_kobj = NULL;
> > + ret = hp_add_other_attributes(HPWMI_SECURE_PLATFORM_TYPE);
> > + if (ret)
> > + pr_debug("Failed to populate secure platform object type attribute\n");
> > +
> > + bioscfg_drv.sure_start_attr_kobj = NULL;
> > + ret = hp_add_other_attributes(HPWMI_SURE_START_TYPE);
> > + if (ret)
> > + pr_debug("Failed to populate sure start object type attribute\n");
> > +
> > + return 0;
> > +
> > +err_release_attributes_data:
> > + release_attributes_data();
> > +
> > +err_destroy_classdev:
> > + device_destroy(fw_attr_class, MKDEV(0, 0));
> > +
> > +err_unregister_class:
> > + fw_attributes_class_put();
> > +
> > +err_exit_bios_attr_pass_interface:
> > + exit_bios_attr_pass_interface();
> > +
> > +err_exit_bios_attr_set_interface:
> > + exit_bios_attr_set_interface();
> > +
> > + return ret;
> > +}
> > +
> > +static void __exit bioscfg_exit(void)
> > +{
> > + release_attributes_data();
> > + device_destroy(fw_attr_class, MKDEV(0, 0));
> > +
> > + fw_attributes_class_put();
> > + exit_bios_attr_set_interface();
> > + exit_bios_attr_pass_interface();
> > +}
> > +
> > +module_init(bioscfg_init);
> > +module_exit(bioscfg_exit);
> > --
> > 2.34.1
> >
On 2023-05-02 14:52:14-0500, Jorge Lopez wrote:
> On Sat, Apr 22, 2023 at 5:16 PM <thomas@t-8ch.de> wrote:
> >
> > On 2023-04-20 11:54:43-0500, Jorge Lopez wrote:
> > > ---
> > > drivers/platform/x86/hp/hp-bioscfg/bioscfg.c | 961 +++++++++++++++++++
> > > 1 file changed, 961 insertions(+)
> > > create mode 100644 drivers/platform/x86/hp/hp-bioscfg/bioscfg.c
> > >
> > > diff --git a/drivers/platform/x86/hp/hp-bioscfg/bioscfg.c b/drivers/platform/x86/hp/hp-bioscfg/bioscfg.c
> > > new file mode 100644
> > > index 000000000000..4b0d4f56e65f
> > > --- /dev/null
> > > +++ b/drivers/platform/x86/hp/hp-bioscfg/bioscfg.c
<snip>
> > > + int retval = 0;
> > > + u8 *attr_name;
> >
> > const char *
>
> Cannot define attr_name as 'const char *'. attr_name value is set
> within the function
Then use "char *". This is pointing to a NULL-terminated string,
not a number or binary data.
This is also the type used by the functions this value is passed to.
<snip>
> > > + retval = kobject_init_and_add(attr_name_kobj, &attr_name_ktype,
> > > + NULL, "%s", str_value);
> > > +
> > > + if (retval) {
> > > + kobject_put(attr_name_kobj);
> >
> > The kobj was not created, why does it need the kobj_put() ?
> As indicated by kobject_init_and_add ...
>
> * This function combines the call to kobject_init() and kobject_add().
> *
> * If this function returns an error, kobject_put() must be called to
> * properly clean up the memory associated with the object. This is the
> * same type of error handling after a call to kobject_add() and kobject
> * lifetime rules are the same here.
I stand corrected, thanks!
> >
> > > + goto err_attr_init;
> > > + }
> > > +
> > > + /* enumerate all of these attributes */
> > > + switch (attr_type) {
> > > + case HPWMI_STRING_TYPE:
> > > + retval = populate_string_package_data(elements,
> > > + instance_id,
> > > + attr_name_kobj);
> > > + break;
> > > + case HPWMI_INTEGER_TYPE:
> > > + retval = populate_integer_package_data(elements,
> > > + instance_id,
> > > + attr_name_kobj);
> > > + break;
> > > + case HPWMI_ENUMERATION_TYPE:
> > > + retval = populate_enumeration_package_data(elements,
> > > + instance_id,
> > > + attr_name_kobj);
> > > + break;
> > > + case HPWMI_ORDERED_LIST_TYPE:
> > > + retval = populate_ordered_list_package_data(elements,
> > > + instance_id,
> > > + attr_name_kobj);
> > > + break;
> > > + case HPWMI_PASSWORD_TYPE:
> > > + retval = populate_password_package_data(elements,
> > > + instance_id,
> > > + attr_name_kobj);
> > > + break;
> > > + default:
> > > + break;
> >
> > This default does nothing.
> >
> > > + }
> > > +
> > > + kfree(str_value);
> >
> > Why is str_value only freed down here? It has not been used for half a
> > screen of code.
>
> Added early in the development process and failed to clean up here.
> >
> > > + }
> >
> > else
> >
> > > +
> > > + if (obj->type == ACPI_TYPE_BUFFER) {
> > > +
> > > + buffer_size = obj->buffer.length;
> > > + buffer_ptr = obj->buffer.pointer;
> > > +
> > > + retval = get_string_from_buffer(&buffer_ptr, &buffer_size, str, MAX_BUFF);
> > > + if (retval < 0)
> > > + goto err_attr_init;
> > > +
> > > + if (attr_type == HPWMI_PASSWORD_TYPE || attr_type == HPWMI_SECURE_PLATFORM_TYPE)
> > > + tmp_set = bioscfg_drv.authentication_dir_kset;
> > > + else
> > > + tmp_set = bioscfg_drv.main_dir_kset;
> >
> > There is a bunch of common logic duplicated in both the buffer and
> > package branches.
>
> Older BIOS reports the ACPI data as objects of type ACPI_TYPE_PACKAGE
> and the associated data is reported as elements.
> Newer BIOS reports the ACPI data as objects of type ACPI_TYPE_BUFFER.
> (actypes.h union acpi_object)
> The code follows a common logic although the data is acquired
> differently according to the ACPI object type
> >
> > > +
> > > + if (kset_find_obj(tmp_set, str)) {
> > > + pr_warn("Duplicate attribute name found - %s\n", str);
> >
> > Also mention that it is being ignored.
> >
> > > + goto nextobj;
> > > + }
> > > +
> > > + /* build attribute */
> > > + attr_name_kobj = kzalloc(sizeof(*attr_name_kobj), GFP_KERNEL);
> > > + if (!attr_name_kobj) {
> > > + retval = -ENOMEM;
> > > + goto err_attr_init;
> > > + }
> > > +
> > > + attr_name_kobj->kset = tmp_set;
> > > +
> > > + temp_str = str;
> > > + if (attr_type == HPWMI_SECURE_PLATFORM_TYPE)
> > > + temp_str = "SPM";
> > > +
> > > + retval = kobject_init_and_add(attr_name_kobj,
> > > + &attr_name_ktype, NULL, "%s",
> > > + temp_str);
> > > + if (retval) {
> > > + kobject_put(attr_name_kobj);
> > > + goto err_attr_init;
> > > + }
> > > +
> > > + /* enumerate all of these attributes */
> > > + switch (attr_type) {
> > > + case HPWMI_STRING_TYPE:
> > > + retval = populate_string_buffer_data(buffer_ptr,
> > > + &buffer_size,
> > > + instance_id,
> > > + attr_name_kobj);
> > > + break;
> > > + case HPWMI_INTEGER_TYPE:
> > > + retval = populate_integer_buffer_data(buffer_ptr,
> > > + &buffer_size,
> > > + instance_id,
> > > + attr_name_kobj);
> > > + break;
> > > + case HPWMI_ENUMERATION_TYPE:
> > > + retval = populate_enumeration_buffer_data(buffer_ptr,
> > > + &buffer_size,
> > > + instance_id,
> > > + attr_name_kobj);
> > > + break;
> > > + case HPWMI_ORDERED_LIST_TYPE:
> > > + retval = populate_ordered_list_buffer_data(buffer_ptr,
> > > + &buffer_size,
> > > + instance_id,
> > > + attr_name_kobj);
> > > + break;
> > > + case HPWMI_PASSWORD_TYPE:
> > > + retval = populate_password_buffer_data(buffer_ptr,
> > > + &buffer_size,
> > > + instance_id,
> > > + attr_name_kobj);
> > > + break;
> > > + default:
> > > + break;
> > > + }
> > > + }
> >
> > What if it's neither a package nor a buffer?
>
> we return an error if it is neither a package nor a buffer.
>
> if (obj->type != ACPI_TYPE_PACKAGE && obj->type != ACPI_TYPE_BUFFER) {
> pr_err("Error: Expected ACPI-package or buffer type, got:
> %d\n", obj->type);
> retval = -EIO;
> goto err_attr_init;
> }
Indeed, thanks.
This could be pulled together into:
if (package)
...
else if (buffer)
...
else
report error
Note:
The "Error: " prefix is unnecessary. It's already logged as pr_err().
<snip>
On Tue, May 2, 2023 at 4:14 PM Thomas Weißschuh <thomas@t-8ch.de> wrote:
>
> On 2023-05-02 14:52:14-0500, Jorge Lopez wrote:
> > On Sat, Apr 22, 2023 at 5:16 PM <thomas@t-8ch.de> wrote:
> > >
> > > On 2023-04-20 11:54:43-0500, Jorge Lopez wrote:
> > > > ---
> > > > drivers/platform/x86/hp/hp-bioscfg/bioscfg.c | 961 +++++++++++++++++++
> > > > 1 file changed, 961 insertions(+)
> > > > create mode 100644 drivers/platform/x86/hp/hp-bioscfg/bioscfg.c
> > > >
> > > > diff --git a/drivers/platform/x86/hp/hp-bioscfg/bioscfg.c b/drivers/platform/x86/hp/hp-bioscfg/bioscfg.c
> > > > new file mode 100644
> > > > index 000000000000..4b0d4f56e65f
> > > > --- /dev/null
> > > > +++ b/drivers/platform/x86/hp/hp-bioscfg/bioscfg.c
>
> <snip>
>
> > > > + int retval = 0;
> > > > + u8 *attr_name;
> > >
> > > const char *
> >
> > Cannot define attr_name as 'const char *'. attr_name value is set
> > within the function
>
> Then use "char *". This is pointing to a NULL-terminated string,
> not a number or binary data.
>
> This is also the type used by the functions this value is passed to.
Done!
>
> <snip>
>
> > > > + retval = kobject_init_and_add(attr_name_kobj, &attr_name_ktype,
> > > > + NULL, "%s", str_value);
> > > > +
> > > > + if (retval) {
> > > > + kobject_put(attr_name_kobj);
> > >
> > > The kobj was not created, why does it need the kobj_put() ?
> > As indicated by kobject_init_and_add ...
> >
> > * This function combines the call to kobject_init() and kobject_add().
> > *
> > * If this function returns an error, kobject_put() must be called to
> > * properly clean up the memory associated with the object. This is the
> > * same type of error handling after a call to kobject_add() and kobject
> > * lifetime rules are the same here.
>
> I stand corrected, thanks!
>
> > >
> > > > + goto err_attr_init;
> > > > + }
> > > > +
> > > > + /* enumerate all of these attributes */
> > > > + switch (attr_type) {
> > > > + case HPWMI_STRING_TYPE:
> > > > + retval = populate_string_package_data(elements,
> > > > + instance_id,
> > > > + attr_name_kobj);
> > > > + break;
> > > > + case HPWMI_INTEGER_TYPE:
> > > > + retval = populate_integer_package_data(elements,
> > > > + instance_id,
> > > > + attr_name_kobj);
> > > > + break;
> > > > + case HPWMI_ENUMERATION_TYPE:
> > > > + retval = populate_enumeration_package_data(elements,
> > > > + instance_id,
> > > > + attr_name_kobj);
> > > > + break;
> > > > + case HPWMI_ORDERED_LIST_TYPE:
> > > > + retval = populate_ordered_list_package_data(elements,
> > > > + instance_id,
> > > > + attr_name_kobj);
> > > > + break;
> > > > + case HPWMI_PASSWORD_TYPE:
> > > > + retval = populate_password_package_data(elements,
> > > > + instance_id,
> > > > + attr_name_kobj);
> > > > + break;
> > > > + default:
> > > > + break;
> > >
> > > This default does nothing.
> > >
> > > > + }
> > > > +
> > > > + kfree(str_value);
> > >
> > > Why is str_value only freed down here? It has not been used for half a
> > > screen of code.
> >
> > Added early in the development process and failed to clean up here.
> > >
> > > > + }
> > >
> > > else
> > >
> > > > +
> > > > + if (obj->type == ACPI_TYPE_BUFFER) {
> > > > +
> > > > + buffer_size = obj->buffer.length;
> > > > + buffer_ptr = obj->buffer.pointer;
> > > > +
> > > > + retval = get_string_from_buffer(&buffer_ptr, &buffer_size, str, MAX_BUFF);
> > > > + if (retval < 0)
> > > > + goto err_attr_init;
> > > > +
> > > > + if (attr_type == HPWMI_PASSWORD_TYPE || attr_type == HPWMI_SECURE_PLATFORM_TYPE)
> > > > + tmp_set = bioscfg_drv.authentication_dir_kset;
> > > > + else
> > > > + tmp_set = bioscfg_drv.main_dir_kset;
> > >
> > > There is a bunch of common logic duplicated in both the buffer and
> > > package branches.
> >
> > Older BIOS reports the ACPI data as objects of type ACPI_TYPE_PACKAGE
> > and the associated data is reported as elements.
> > Newer BIOS reports the ACPI data as objects of type ACPI_TYPE_BUFFER.
> > (actypes.h union acpi_object)
> > The code follows a common logic although the data is acquired
> > differently according to the ACPI object type
> > >
> > > > +
> > > > + if (kset_find_obj(tmp_set, str)) {
> > > > + pr_warn("Duplicate attribute name found - %s\n", str);
> > >
> > > Also mention that it is being ignored.
> > >
> > > > + goto nextobj;
> > > > + }
> > > > +
> > > > + /* build attribute */
> > > > + attr_name_kobj = kzalloc(sizeof(*attr_name_kobj), GFP_KERNEL);
> > > > + if (!attr_name_kobj) {
> > > > + retval = -ENOMEM;
> > > > + goto err_attr_init;
> > > > + }
> > > > +
> > > > + attr_name_kobj->kset = tmp_set;
> > > > +
> > > > + temp_str = str;
> > > > + if (attr_type == HPWMI_SECURE_PLATFORM_TYPE)
> > > > + temp_str = "SPM";
> > > > +
> > > > + retval = kobject_init_and_add(attr_name_kobj,
> > > > + &attr_name_ktype, NULL, "%s",
> > > > + temp_str);
> > > > + if (retval) {
> > > > + kobject_put(attr_name_kobj);
> > > > + goto err_attr_init;
> > > > + }
> > > > +
> > > > + /* enumerate all of these attributes */
> > > > + switch (attr_type) {
> > > > + case HPWMI_STRING_TYPE:
> > > > + retval = populate_string_buffer_data(buffer_ptr,
> > > > + &buffer_size,
> > > > + instance_id,
> > > > + attr_name_kobj);
> > > > + break;
> > > > + case HPWMI_INTEGER_TYPE:
> > > > + retval = populate_integer_buffer_data(buffer_ptr,
> > > > + &buffer_size,
> > > > + instance_id,
> > > > + attr_name_kobj);
> > > > + break;
> > > > + case HPWMI_ENUMERATION_TYPE:
> > > > + retval = populate_enumeration_buffer_data(buffer_ptr,
> > > > + &buffer_size,
> > > > + instance_id,
> > > > + attr_name_kobj);
> > > > + break;
> > > > + case HPWMI_ORDERED_LIST_TYPE:
> > > > + retval = populate_ordered_list_buffer_data(buffer_ptr,
> > > > + &buffer_size,
> > > > + instance_id,
> > > > + attr_name_kobj);
> > > > + break;
> > > > + case HPWMI_PASSWORD_TYPE:
> > > > + retval = populate_password_buffer_data(buffer_ptr,
> > > > + &buffer_size,
> > > > + instance_id,
> > > > + attr_name_kobj);
> > > > + break;
> > > > + default:
> > > > + break;
> > > > + }
> > > > + }
> > >
> > > What if it's neither a package nor a buffer?
> >
> > we return an error if it is neither a package nor a buffer.
> >
> > if (obj->type != ACPI_TYPE_PACKAGE && obj->type != ACPI_TYPE_BUFFER) {
> > pr_err("Error: Expected ACPI-package or buffer type, got:
> > %d\n", obj->type);
> > retval = -EIO;
> > goto err_attr_init;
> > }
>
> Indeed, thanks.
>
> This could be pulled together into:
>
> if (package)
> ...
> else if (buffer)
> ...
> else
> report error
Done!
> Note:
>
> The "Error: " prefix is unnecessary. It's already logged as pr_err().
>
Good catch. Thank you. Done!
> <snip>
new file mode 100644
@@ -0,0 +1,961 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Common methods for use with hp-bioscfg driver
+ *
+ * Copyright (c) 2022 HP Development Company, L.P.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/fs.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/wmi.h>
+#include "bioscfg.h"
+#include "../../firmware_attributes_class.h"
+#include <linux/nls.h>
+#include <linux/errno.h>
+
+MODULE_AUTHOR("Jorge Lopez <jorge.lopez2@hp.com>");
+MODULE_DESCRIPTION("HP BIOS Configuration Driver");
+MODULE_LICENSE("GPL");
+
+struct bioscfg_priv bioscfg_drv = {
+ .mutex = __MUTEX_INITIALIZER(bioscfg_drv.mutex),
+};
+
+static struct class *fw_attr_class;
+
+int get_integer_from_buffer(int **buffer, u32 *buffer_size, int *integer)
+{
+ int *ptr = PTR_ALIGN(*buffer, 4);
+
+ /* Ensure there is enough space remaining to read the integer */
+ if (*buffer_size < sizeof(int))
+ return -EINVAL;
+
+ *integer = *(ptr++);
+ *buffer = ptr;
+ *buffer_size -= sizeof(int);
+
+ return 0;
+}
+
+
+int get_string_from_buffer(u8 **buffer, u32 *buffer_size, char *dst, u32 dst_size)
+{
+ u16 *src = (u16 *)*buffer;
+ u16 src_size;
+
+ u16 size;
+ int i;
+ int escape = 0;
+ int conv_dst_size;
+
+ if (*buffer_size < sizeof(u16))
+ return -EINVAL;
+
+ src_size = *(src++);
+ /* size value in u16 chars */
+ size = src_size / sizeof(u16);
+
+ /* Ensure there is enough space remaining to read and convert
+ * the string
+ */
+ if (*buffer_size < src_size)
+ return -EINVAL;
+
+ for (i = 0; i < size; i++)
+ if (src[i] == '\\' ||
+ src[i] == '\r' ||
+ src[i] == '\n' ||
+ src[i] == '\t')
+ escape++;
+
+ size += escape;
+
+ /*
+ * Conversion is limited to destination string max number of
+ * bytes.
+ */
+ conv_dst_size = size;
+ if (size > dst_size)
+ conv_dst_size = dst_size - 1;
+
+ /*
+ * convert from UTF-16 unicode to ASCII
+ */
+ utf16s_to_utf8s(src, src_size, UTF16_HOST_ENDIAN, dst, conv_dst_size);
+ dst[conv_dst_size] = 0;
+
+ for (i = 0; i < size && i < conv_dst_size; i++) {
+ if (*src == '\\' ||
+ *src == '\r' ||
+ *src == '\n' ||
+ *src == '\t')
+ dst[i++] = '\\';
+
+ if (*src == '\r')
+ dst[i] = 'r';
+ else if (*src == '\n')
+ dst[i] = 'n';
+ else if (*src == '\t')
+ dst[i] = 't';
+ else if (*src == '"')
+ dst[i] = '\'';
+ else
+ dst[i] = *src;
+ src++;
+ }
+
+ *buffer = (u8 *)src;
+ *buffer_size -= size * sizeof(u16);
+
+ return size;
+}
+
+
+/*
+ * calculate_string_buffer() - determines size of string buffer for use with BIOS communication
+ * @str: the string to calculate based upon
+ */
+size_t bioscfg_calculate_string_buffer(const char *str)
+{
+ int length = strlen(str);
+ int size;
+
+ /* BIOS expects 4 bytes when an empty string is found */
+ if (!length)
+ length = 1;
+
+ /* u16 length field + one UTF16 char for each input char */
+ size = sizeof(u16) + length * sizeof(u16);
+
+ return size;
+}
+
+int bioscfg_wmi_error_and_message(int error_code)
+{
+ char *error_msg = NULL;
+ int ret;
+
+ switch (error_code) {
+ case SUCCESS:
+ error_msg = "Success";
+ ret = 0;
+ break;
+ case CMD_FAILED:
+ error_msg = "Command failed";
+ ret = -EINVAL;
+ break;
+ case INVALID_SIGN:
+ error_msg = "Invalid signature";
+ ret = -EINVAL;
+ break;
+ case INVALID_CMD_VALUE:
+ error_msg = "Invalid command value/Feature not supported";
+ ret = -EOPNOTSUPP;
+ break;
+ case INVALID_CMD_TYPE:
+ error_msg = "Invalid command type";
+ ret = -EINVAL;
+ break;
+ case INVALID_DATA_SIZE:
+ error_msg = "Invalid data size";
+ ret = -EINVAL;
+ break;
+ case INVALID_CMD_PARAM:
+ error_msg = "Invalid command parameter";
+ ret = -EINVAL;
+ break;
+ case ENCRYP_CMD_REQUIRED:
+ error_msg = "Secure/encrypted command required";
+ ret = -EACCES;
+ break;
+ case NO_SECURE_SESSION:
+ error_msg = "No secure session established";
+ ret = -EACCES;
+ break;
+ case SECURE_SESSION_FOUND:
+ error_msg = "Secure session already established";
+ ret = -EACCES;
+ break;
+ case SECURE_SESSION_FAILED:
+ error_msg = "Secure session failed";
+ ret = -EIO;
+ break;
+ case AUTH_FAILED:
+ error_msg = "Other permission/Authentication failed";
+ ret = -EACCES;
+ break;
+ case INVALID_BIOS_AUTH:
+ error_msg = "Invalid BIOS administrator password";
+ ret = -EINVAL;
+ break;
+ case NONCE_DID_NOT_MATCH:
+ error_msg = "Nonce did not match";
+ ret = -EINVAL;
+ break;
+ case GENERIC_ERROR:
+ error_msg = "Generic/Other error";
+ ret = -EIO;
+ break;
+ case BIOS_ADMIN_POLICY_NOT_MET:
+ error_msg = "BIOS Admin password does not meet password policy requirements";
+ ret = -EINVAL;
+ break;
+ case BIOS_ADMIN_NOT_SET:
+ error_msg = "BIOS Setup password is not set.";
+ ret = -EPERM;
+ break;
+ case P21_NO_PROVISIONED:
+ error_msg = "P21 is not provisioned";
+ ret = -EPERM;
+ break;
+ case P21_PROVISION_IN_PROGRESS:
+ error_msg = "P21 is already provisioned or provisioning is in progress and a signing key has already been sent.";
+ ret = -EINPROGRESS;
+ break;
+ case P21_IN_USE:
+ error_msg = "P21 in use (cannot deprovision)";
+ ret = -EPERM;
+ break;
+ case HEP_NOT_ACTIVE:
+ error_msg = "HEP not activated";
+ ret = -EPERM;
+ break;
+ case HEP_ALREADY_SET:
+ error_msg = "HEP Transport already set";
+ ret = -EINVAL;
+ break;
+ case HEP_CHECK_STATE:
+ error_msg = "Check the current HEP state";
+ ret = -EINVAL;
+ break;
+ default:
+ error_msg = "Generic/Other error";
+ ret = -EIO;
+ break;
+ }
+
+ if (error_code)
+ pr_warn_ratelimited("Returned error 0x%x, \"%s\"\n", error_code, error_msg);
+
+ return ret;
+}
+
+
+/*
+ * pending_reboot_show() - sysfs implementaton for read pending_reboot
+ * @kobj: Kernel object for this attribute
+ * @attr: Kernel object attribute
+ * @buf: The buffer to display to userspace
+ *
+ * Stores default value as 0
+ * When current_value is changed this attribute is set to 1 to notify reboot may be required
+ */
+static ssize_t pending_reboot_show(struct kobject *kobj,
+ struct kobj_attribute *attr,
+ char *buf)
+{
+ return sysfs_emit(buf, "%d\n", bioscfg_drv.pending_reboot);
+}
+static struct kobj_attribute pending_reboot = __ATTR_RO(pending_reboot);
+
+/*
+ * create_attributes_level_sysfs_files() - Creates pending_reboot attributes
+ */
+static int create_attributes_level_sysfs_files(void)
+{
+ int ret;
+
+ ret = sysfs_create_file(&bioscfg_drv.main_dir_kset->kobj, &pending_reboot.attr);
+ if (ret)
+ return ret;
+
+ return 0;
+}
+
+
+static void attr_name_release(struct kobject *kobj)
+{
+ kfree(kobj);
+}
+
+static const struct kobj_type attr_name_ktype = {
+ .release = attr_name_release,
+ .sysfs_ops = &kobj_sysfs_ops,
+};
+
+/*
+ * get_wmiobj_pointer() - Get Content of WMI block for particular instance
+ *
+ * @instance_id: WMI instance ID
+ * @guid_string: WMI GUID (in str form)
+ *
+ * Fetches the content for WMI block (instance_id) under GUID (guid_string)
+ * Caller must kfree the return
+ */
+union acpi_object *get_wmiobj_pointer(int instance_id, const char *guid_string)
+{
+ struct acpi_buffer out = { ACPI_ALLOCATE_BUFFER, NULL };
+ acpi_status status;
+
+ status = wmi_query_block(guid_string, instance_id, &out);
+ return ACPI_SUCCESS(status) ? (union acpi_object *)out.pointer : NULL;
+}
+
+/*
+ * get_instance_count() - Compute total number of instances under guid_string
+ *
+ * @guid_string: WMI GUID (in string form)
+ */
+int get_instance_count(const char *guid_string)
+{
+ union acpi_object *wmi_obj = NULL;
+ int i = 0;
+
+ do {
+ kfree(wmi_obj);
+ wmi_obj = get_wmiobj_pointer(i, guid_string);
+ i++;
+ } while (wmi_obj);
+
+ return i-1;
+}
+
+/*
+ * alloc_attributes_data() - Allocate attributes data for a particular type
+ *
+ * @attr_type: Attribute type to allocate
+ */
+static int alloc_attributes_data(int attr_type)
+{
+ int retval = 0;
+
+ switch (attr_type) {
+ case HPWMI_STRING_TYPE:
+ retval = alloc_string_data();
+ break;
+ case HPWMI_INTEGER_TYPE:
+ retval = alloc_integer_data();
+ break;
+ case HPWMI_ENUMERATION_TYPE:
+ retval = alloc_enumeration_data();
+ break;
+ case HPWMI_ORDERED_LIST_TYPE:
+ retval = alloc_ordered_list_data();
+ break;
+ case HPWMI_PASSWORD_TYPE:
+ retval = alloc_password_data();
+ break;
+ default:
+ break;
+ }
+
+ return retval;
+}
+
+int convert_hexstr_to_str(const char *input, u32 input_len, char **str, int *len)
+{
+ int ret = 0;
+ int new_len = 0;
+ char tmp[] = "0x00";
+ char *new_str = NULL;
+ long ch;
+ int i;
+
+ if (input_len <= 0 || input == NULL || str == NULL || len == NULL)
+ return -EINVAL;
+
+ *len = 0;
+ *str = NULL;
+
+ new_str = kmalloc(input_len, GFP_KERNEL);
+ if (!new_str)
+ return -ENOMEM;
+
+ for (i = 0; i < input_len; i += 5) {
+ strncpy(tmp, input + i, strlen(tmp));
+ if (kstrtol(tmp, 16, &ch) == 0) {
+ // escape char
+ if (ch == '\\' || ch == '\r' || ch == '\n' || ch == '\t') {
+ if (ch == '\r')
+ ch = 'r';
+ else if (ch == '\n')
+ ch = 'n';
+ else if (ch == '\t')
+ ch = 't';
+ new_str[new_len++] = '\\';
+ }
+ new_str[new_len++] = ch;
+ if (ch == '\0')
+ break;
+ }
+ }
+
+ if (new_len) {
+ new_str[new_len] = '\0';
+ *str = krealloc(new_str, (new_len + 1) * sizeof(char), GFP_KERNEL);
+ if (*str)
+ *len = new_len;
+ else
+ ret = -ENOMEM;
+ } else {
+ ret = -EFAULT;
+ }
+
+ if (ret)
+ kfree(new_str);
+ return ret;
+}
+
+/* map output size to the corresponding WMI method id */
+int encode_outsize_for_pvsz(int outsize)
+{
+ if (outsize > 4096)
+ return -EINVAL;
+ if (outsize > 1024)
+ return 5;
+ if (outsize > 128)
+ return 4;
+ if (outsize > 4)
+ return 3;
+ if (outsize > 0)
+ return 2;
+ return 1;
+}
+
+/*
+ * Update friendly display name for several attributes associated to
+ * 'Schedule Power-On'
+ */
+void friendly_user_name_update(char *path, const char *attr_name,
+ char *attr_display, int attr_size)
+{
+ char *found = NULL;
+
+ found = strstr(path, SCHEDULE_POWER_ON);
+ if (found)
+ snprintf(attr_display,
+ attr_size,
+ "%s - %s",
+ SCHEDULE_POWER_ON,
+ attr_name);
+ else
+ strscpy(attr_display, attr_name, attr_size);
+}
+
+/*
+ * update_attribute_permissions() - Update attributes permissions when
+ * isReadOnly value is 1
+ *
+ * @isReadOnly: ReadOnly value
+ * @current_val: kobj_attribute corresponding to attribute.
+ *
+ */
+void update_attribute_permissions(u32 isReadOnly, struct kobj_attribute *current_val)
+{
+ if (isReadOnly)
+ current_val->attr.mode = (umode_t)0444;
+ else
+ current_val->attr.mode = (umode_t)0644;
+}
+
+
+/**
+ * destroy_attribute_objs() - Free a kset of kobjects
+ * @kset: The kset to destroy
+ *
+ * Fress kobjects created for each attribute_name under attribute type kset
+ */
+static void destroy_attribute_objs(struct kset *kset)
+{
+ struct kobject *pos, *next;
+
+ list_for_each_entry_safe(pos, next, &kset->list, entry)
+ kobject_put(pos);
+}
+
+/**
+ * release_attributes_data() - Clean-up all sysfs directories and files created
+ */
+static void release_attributes_data(void)
+{
+ mutex_lock(&bioscfg_drv.mutex);
+
+ exit_string_attributes();
+ exit_integer_attributes();
+ exit_enumeration_attributes();
+ exit_ordered_list_attributes();
+ exit_password_attributes();
+ exit_sure_start_attributes();
+ exit_secure_platform_attributes();
+
+ if (bioscfg_drv.authentication_dir_kset) {
+ destroy_attribute_objs(bioscfg_drv.authentication_dir_kset);
+ kset_unregister(bioscfg_drv.authentication_dir_kset);
+ bioscfg_drv.authentication_dir_kset = NULL;
+ }
+ if (bioscfg_drv.main_dir_kset) {
+ sysfs_remove_file(&bioscfg_drv.main_dir_kset->kobj, &pending_reboot.attr);
+ destroy_attribute_objs(bioscfg_drv.main_dir_kset);
+ kset_unregister(bioscfg_drv.main_dir_kset);
+ bioscfg_drv.main_dir_kset = NULL;
+ }
+ mutex_unlock(&bioscfg_drv.mutex);
+}
+
+
+/*
+ * hp_add_other_attributes - Initialize HP custom attributes not reported by
+ * BIOS and required to support Secure Platform, Sure Start, and Sure
+ * Admin.
+ * @attr_type: Custom HP attribute not reported by BIOS
+ *
+ * Initialiaze all 3 types of attributes: Platform, Sure Start, and Sure
+ * Admin object. Populates each attrbute types respective properties
+ * under sysfs files.
+ *
+ * Returns zero(0) if successful. Otherwise, a negative value.
+ */
+static int hp_add_other_attributes(int attr_type)
+{
+ struct kobject *attr_name_kobj;
+ union acpi_object *obj = NULL;
+ int retval = 0;
+ u8 *attr_name;
+
+ mutex_lock(&bioscfg_drv.mutex);
+
+ attr_name_kobj = kzalloc(sizeof(*attr_name_kobj), GFP_KERNEL);
+ if (!attr_name_kobj) {
+ retval = -ENOMEM;
+ goto err_other_attr_init;
+ }
+
+ /* Check if attribute type is supported */
+ switch (attr_type) {
+ case HPWMI_SECURE_PLATFORM_TYPE:
+ attr_name_kobj->kset = bioscfg_drv.authentication_dir_kset;
+ attr_name = SPM_STR;
+ break;
+
+ case HPWMI_SURE_START_TYPE:
+ attr_name_kobj->kset = bioscfg_drv.main_dir_kset;
+ attr_name = SURE_START_STR;
+ break;
+
+ default:
+ pr_err("Error: Unknown attr_type: %d\n", attr_type);
+ retval = -EINVAL;
+ goto err_other_attr_init;
+ }
+
+ retval = kobject_init_and_add(attr_name_kobj, &attr_name_ktype,
+ NULL, "%s", attr_name);
+ if (retval) {
+ pr_err("Error encountered [%d]\n", retval);
+ kobject_put(attr_name_kobj);
+ goto err_other_attr_init;
+ }
+
+ /* Populate attribute data */
+ switch (attr_type) {
+ case HPWMI_SECURE_PLATFORM_TYPE:
+ retval = populate_secure_platform_data(attr_name_kobj);
+ break;
+
+ case HPWMI_SURE_START_TYPE:
+ retval = populate_sure_start_data(attr_name_kobj);
+ break;
+
+ default:
+ goto err_other_attr_init;
+ }
+
+ mutex_unlock(&bioscfg_drv.mutex);
+ return 0;
+
+err_other_attr_init:
+ mutex_unlock(&bioscfg_drv.mutex);
+ kfree(obj);
+ return retval;
+}
+
+/*
+ * hp_init_bios_attributes - Initialize all attributes for a type
+ * @attr_type: The attribute type to initialize
+ * @guid: The WMI GUID associated with this type to initialize
+ *
+ * Initialiaze all 5 types of attributes: enumeration, integer,
+ * string, password, ordered list object. Populates each attrbute types
+ * respective properties under sysfs files
+ */
+static int hp_init_bios_attributes(int attr_type, const char *guid)
+{
+ struct kobject *attr_name_kobj;
+ union acpi_object *obj = NULL;
+ union acpi_object *elements;
+ struct kset *tmp_set;
+ int min_elements;
+ char str[MAX_BUFF];
+
+ char *temp_str = NULL;
+ char *str_value = NULL;
+ int str_len;
+ int ret = 0;
+
+ u8 *buffer_ptr = NULL;
+ int buffer_size;
+
+
+ /* instance_id needs to be reset for each type GUID
+ * also, instance IDs are unique within GUID but not across
+ */
+ int instance_id = 0;
+ int retval = 0;
+
+ retval = alloc_attributes_data(attr_type);
+ if (retval)
+ return retval;
+
+ switch (attr_type) {
+ case HPWMI_STRING_TYPE:
+ min_elements = 12;
+ break;
+ case HPWMI_INTEGER_TYPE:
+ min_elements = 13;
+ break;
+ case HPWMI_ENUMERATION_TYPE:
+ min_elements = 13;
+ break;
+ case HPWMI_ORDERED_LIST_TYPE:
+ min_elements = 12;
+ break;
+ case HPWMI_PASSWORD_TYPE:
+ min_elements = 15;
+ break;
+ default:
+ pr_err("Error: Unknown attr_type: %d\n", attr_type);
+ return -EINVAL;
+ }
+
+ /* need to use specific instance_id and guid combination to get right data */
+ obj = get_wmiobj_pointer(instance_id, guid);
+ if (!obj)
+ return -ENODEV;
+
+ mutex_lock(&bioscfg_drv.mutex);
+ while (obj) {
+ if (obj->type != ACPI_TYPE_PACKAGE && obj->type != ACPI_TYPE_BUFFER) {
+ pr_err("Error: Expected ACPI-package or buffer type, got: %d\n", obj->type);
+ retval = -EIO;
+ goto err_attr_init;
+ }
+
+ /* Take action appropriate to each ACPI TYPE */
+ if (obj->type == ACPI_TYPE_PACKAGE) {
+ if (obj->package.count < min_elements) {
+ pr_err("ACPI-package does not have enough elements: %d < %d\n",
+ obj->package.count, min_elements);
+ goto nextobj;
+ }
+
+ elements = obj->package.elements;
+
+ /* sanity checking */
+ if (elements[NAME].type != ACPI_TYPE_STRING) {
+ pr_debug("incorrect element type\n");
+ goto nextobj;
+ }
+ if (strlen(elements[NAME].string.pointer) == 0) {
+ pr_debug("empty attribute found\n");
+ goto nextobj;
+ }
+
+ if (attr_type == HPWMI_PASSWORD_TYPE)
+ tmp_set = bioscfg_drv.authentication_dir_kset;
+ else
+ tmp_set = bioscfg_drv.main_dir_kset;
+
+ /* convert attribute name to string */
+ retval = convert_hexstr_to_str(elements[NAME].string.pointer,
+ elements[NAME].string.length,
+ &str_value, &str_len);
+
+ if (retval) {
+ pr_debug("Failed to populate integer package data. Error [0%0x]\n", ret);
+ kfree(str_value);
+ return ret;
+ }
+
+ if (kset_find_obj(tmp_set, str_value)) {
+ pr_debug("Duplicate attribute name found - %s\n",
+ str_value);
+ goto nextobj;
+ }
+
+ /* build attribute */
+ attr_name_kobj = kzalloc(sizeof(*attr_name_kobj), GFP_KERNEL);
+ if (!attr_name_kobj) {
+ retval = -ENOMEM;
+ goto err_attr_init;
+ }
+
+ attr_name_kobj->kset = tmp_set;
+
+ retval = kobject_init_and_add(attr_name_kobj, &attr_name_ktype,
+ NULL, "%s", str_value);
+
+ if (retval) {
+ kobject_put(attr_name_kobj);
+ goto err_attr_init;
+ }
+
+ /* enumerate all of these attributes */
+ switch (attr_type) {
+ case HPWMI_STRING_TYPE:
+ retval = populate_string_package_data(elements,
+ instance_id,
+ attr_name_kobj);
+ break;
+ case HPWMI_INTEGER_TYPE:
+ retval = populate_integer_package_data(elements,
+ instance_id,
+ attr_name_kobj);
+ break;
+ case HPWMI_ENUMERATION_TYPE:
+ retval = populate_enumeration_package_data(elements,
+ instance_id,
+ attr_name_kobj);
+ break;
+ case HPWMI_ORDERED_LIST_TYPE:
+ retval = populate_ordered_list_package_data(elements,
+ instance_id,
+ attr_name_kobj);
+ break;
+ case HPWMI_PASSWORD_TYPE:
+ retval = populate_password_package_data(elements,
+ instance_id,
+ attr_name_kobj);
+ break;
+ default:
+ break;
+ }
+
+ kfree(str_value);
+ }
+
+ if (obj->type == ACPI_TYPE_BUFFER) {
+
+ buffer_size = obj->buffer.length;
+ buffer_ptr = obj->buffer.pointer;
+
+ retval = get_string_from_buffer(&buffer_ptr, &buffer_size, str, MAX_BUFF);
+ if (retval < 0)
+ goto err_attr_init;
+
+ if (attr_type == HPWMI_PASSWORD_TYPE || attr_type == HPWMI_SECURE_PLATFORM_TYPE)
+ tmp_set = bioscfg_drv.authentication_dir_kset;
+ else
+ tmp_set = bioscfg_drv.main_dir_kset;
+
+ if (kset_find_obj(tmp_set, str)) {
+ pr_warn("Duplicate attribute name found - %s\n", str);
+ goto nextobj;
+ }
+
+ /* build attribute */
+ attr_name_kobj = kzalloc(sizeof(*attr_name_kobj), GFP_KERNEL);
+ if (!attr_name_kobj) {
+ retval = -ENOMEM;
+ goto err_attr_init;
+ }
+
+ attr_name_kobj->kset = tmp_set;
+
+ temp_str = str;
+ if (attr_type == HPWMI_SECURE_PLATFORM_TYPE)
+ temp_str = "SPM";
+
+ retval = kobject_init_and_add(attr_name_kobj,
+ &attr_name_ktype, NULL, "%s",
+ temp_str);
+ if (retval) {
+ kobject_put(attr_name_kobj);
+ goto err_attr_init;
+ }
+
+ /* enumerate all of these attributes */
+ switch (attr_type) {
+ case HPWMI_STRING_TYPE:
+ retval = populate_string_buffer_data(buffer_ptr,
+ &buffer_size,
+ instance_id,
+ attr_name_kobj);
+ break;
+ case HPWMI_INTEGER_TYPE:
+ retval = populate_integer_buffer_data(buffer_ptr,
+ &buffer_size,
+ instance_id,
+ attr_name_kobj);
+ break;
+ case HPWMI_ENUMERATION_TYPE:
+ retval = populate_enumeration_buffer_data(buffer_ptr,
+ &buffer_size,
+ instance_id,
+ attr_name_kobj);
+ break;
+ case HPWMI_ORDERED_LIST_TYPE:
+ retval = populate_ordered_list_buffer_data(buffer_ptr,
+ &buffer_size,
+ instance_id,
+ attr_name_kobj);
+ break;
+ case HPWMI_PASSWORD_TYPE:
+ retval = populate_password_buffer_data(buffer_ptr,
+ &buffer_size,
+ instance_id,
+ attr_name_kobj);
+ break;
+ default:
+ break;
+ }
+ }
+nextobj:
+ kfree(str_value);
+ kfree(obj);
+ instance_id++;
+ obj = get_wmiobj_pointer(instance_id, guid);
+ }
+ mutex_unlock(&bioscfg_drv.mutex);
+ return 0;
+
+err_attr_init:
+ mutex_unlock(&bioscfg_drv.mutex);
+ kfree(obj);
+ return retval;
+}
+
+static int __init bioscfg_init(void)
+{
+ int ret = 0;
+ int bios_capable = wmi_has_guid(HP_WMI_BIOS_GUID);
+
+ if (!bios_capable) {
+ pr_err("Unable to run on non-HP system\n");
+ return -ENODEV;
+ }
+
+ ret = init_bios_attr_set_interface();
+ if (ret)
+ return ret;
+
+ ret = init_bios_attr_pass_interface();
+ if (ret)
+ goto err_exit_bios_attr_set_interface;
+
+ if (!bioscfg_drv.bios_attr_wdev || !bioscfg_drv.password_attr_wdev) {
+ pr_debug("Failed to find set or pass interface\n");
+ ret = -ENODEV;
+ goto err_exit_bios_attr_pass_interface;
+ }
+
+ ret = fw_attributes_class_get(&fw_attr_class);
+ if (ret)
+ goto err_exit_bios_attr_pass_interface;
+
+ bioscfg_drv.class_dev = device_create(fw_attr_class, NULL, MKDEV(0, 0),
+ NULL, "%s", DRIVER_NAME);
+ if (IS_ERR(bioscfg_drv.class_dev)) {
+ ret = PTR_ERR(bioscfg_drv.class_dev);
+ goto err_unregister_class;
+ }
+
+ bioscfg_drv.main_dir_kset = kset_create_and_add("attributes", NULL,
+ &bioscfg_drv.class_dev->kobj);
+ if (!bioscfg_drv.main_dir_kset) {
+ ret = -ENOMEM;
+ pr_debug("Failed to create and add attributes\n");
+ goto err_destroy_classdev;
+ }
+
+ bioscfg_drv.authentication_dir_kset = kset_create_and_add("authentication", NULL,
+ &bioscfg_drv.class_dev->kobj);
+ if (!bioscfg_drv.authentication_dir_kset) {
+ ret = -ENOMEM;
+ pr_debug("Failed to create and add authentication\n");
+ goto err_release_attributes_data;
+ }
+
+ /*
+ * sysfs level attributes.
+ * - pending_reboot
+ */
+ ret = create_attributes_level_sysfs_files();
+ if (ret)
+ pr_debug("Failed to create sysfs level attributes\n");
+
+ ret = hp_init_bios_attributes(HPWMI_STRING_TYPE, HP_WMI_BIOS_STRING_GUID);
+ if (ret)
+ pr_debug("Failed to populate string type attributes\n");
+
+ ret = hp_init_bios_attributes(HPWMI_INTEGER_TYPE, HP_WMI_BIOS_INTEGER_GUID);
+ if (ret)
+ pr_debug("Failed to populate integer type attributes\n");
+
+ ret = hp_init_bios_attributes(HPWMI_ENUMERATION_TYPE, HP_WMI_BIOS_ENUMERATION_GUID);
+ if (ret)
+ pr_debug("Failed to populate enumeration type attributes\n");
+
+ ret = hp_init_bios_attributes(HPWMI_ORDERED_LIST_TYPE, HP_WMI_BIOS_ORDERED_LIST_GUID);
+ if (ret)
+ pr_debug("Failed to populate ordered list object type attributes\n");
+
+ ret = hp_init_bios_attributes(HPWMI_PASSWORD_TYPE, HP_WMI_BIOS_PASSWORD_GUID);
+ if (ret)
+ pr_debug("Failed to populate password object type attributes\n");
+
+ bioscfg_drv.spm_data.attr_name_kobj = NULL;
+ ret = hp_add_other_attributes(HPWMI_SECURE_PLATFORM_TYPE);
+ if (ret)
+ pr_debug("Failed to populate secure platform object type attribute\n");
+
+ bioscfg_drv.sure_start_attr_kobj = NULL;
+ ret = hp_add_other_attributes(HPWMI_SURE_START_TYPE);
+ if (ret)
+ pr_debug("Failed to populate sure start object type attribute\n");
+
+ return 0;
+
+err_release_attributes_data:
+ release_attributes_data();
+
+err_destroy_classdev:
+ device_destroy(fw_attr_class, MKDEV(0, 0));
+
+err_unregister_class:
+ fw_attributes_class_put();
+
+err_exit_bios_attr_pass_interface:
+ exit_bios_attr_pass_interface();
+
+err_exit_bios_attr_set_interface:
+ exit_bios_attr_set_interface();
+
+ return ret;
+}
+
+static void __exit bioscfg_exit(void)
+{
+ release_attributes_data();
+ device_destroy(fw_attr_class, MKDEV(0, 0));
+
+ fw_attributes_class_put();
+ exit_bios_attr_set_interface();
+ exit_bios_attr_pass_interface();
+}
+
+module_init(bioscfg_init);
+module_exit(bioscfg_exit);