HI Hans,
Please see questions and comments below.
On Tue, Nov 8, 2022 at 8:51 AM Hans de Goede <hdegoede@xxxxxxxxxx> wrote:
>
> Hi Jorge,
>
> Review comments inline.
>
> On 10/20/22 22:10, Jorge Lopez wrote:
> > The purpose for this patch is submit HP BIOSCFG driver to be list of
> > HP Linux kernel drivers. The driver include a total of 12 files
> > broken in several patches. This is set 1 of 4.
> >
> > 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 PC’s 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 BISOCFG 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 features such Secure Platform Management, Sure
> > Admin, and Sure Start. Each section provides security feature
> > description and identifies sysfs directories and files exposed by
> > the driver.
> >
> > Many HP Commercial PC’s 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 PC’s 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 Sure Admin cryptographic signature-based authorization string
> > that the BIOS will use to verify authorization to modify the setting.
> >
> > Signed-off-by: Jorge Lopez <jorge.lopez2@xxxxxx>
> >
> > ---
> > Based on the latest platform-drivers-x86.git/for-next
> > ---
> > .../x86/hp/hp-bioscfg/biosattr-interface.c | 285 ++++++++
> > drivers/platform/x86/hp/hp-bioscfg/bioscfg.h | 671 ++++++++++++++++++
> > .../x86/hp/hp-bioscfg/enum-attributes.c | 521 ++++++++++++++
> > 3 files changed, 1477 insertions(+)
> > create mode 100644 drivers/platform/x86/hp/hp-bioscfg/biosattr-interface.c
> > create mode 100644 drivers/platform/x86/hp/hp-bioscfg/bioscfg.h
> > create mode 100644 drivers/platform/x86/hp/hp-bioscfg/enum-attributes.c
> >
> > diff --git a/drivers/platform/x86/hp/hp-bioscfg/biosattr-interface.c b/drivers/platform/x86/hp/hp-bioscfg/biosattr-interface.c
> > new file mode 100644
> > index 000000000000..f0c919bf3ab0
> > --- /dev/null
> > +++ b/drivers/platform/x86/hp/hp-bioscfg/biosattr-interface.c
> > @@ -0,0 +1,285 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * Functions corresponding to methods under BIOS interface GUID
> > + * for use with hp-bioscfg driver.
> > + *
> > + * Copyright (c) 2022 Hewlett-Packard Inc.
> > + */
> > +
> > +#include <linux/wmi.h>
> > +#include "bioscfg.h"
> > +
> > +#define SET_DEFAULT_VALUES_METHOD_ID 0x02
> > +#define SET_BIOS_DEFAULTS_METHOD_ID 0x03
> > +#define SET_ATTRIBUTE_METHOD_ID 0x04
> > +
> > +/*
> > + * set_attribute() - Update an attribute value
> > + * @a_name: The attribute name
> > + * @a_value: The attribute value
> > + *
> > + * Sets an attribute to new value
> > + */
> > +int hp_set_attribute(const char *a_name, const char *a_value)
> > +{
> > + size_t security_area_size;
> > + size_t a_name_size, a_value_size;
> > + u16 *buffer = NULL;
> > + u16 *start = NULL;
> > + int buffer_size;
>
> You have 2 spaces between int and buffer_size here, please drop
> one.
>
>
> > + int ret;
> > + int instance;
> > + char *auth_empty_value = " ";
> > +
> > + mutex_lock(&bioscfg_drv.mutex);
> > + if (!bioscfg_drv.bios_attr_wdev) {
> > + ret = -ENODEV;
> > + goto out_set_attribute;
> > + }
> > +
> > + instance = get_password_instance_for_type(SETUP_PASSWD);
> > + if (instance < 0)
> > + goto out_set_attribute;
> > +
> > + if (strlen(bioscfg_drv.password_data[instance].current_password) == 0)
> > + strncpy(bioscfg_drv.password_data[instance].current_password,
> > + auth_empty_value,
> > + sizeof(bioscfg_drv.password_data[instance].current_password));
>
> strncpy does not guarantee 0 termination of the destination buffer,
> please use strscpy.
>
> > +
> > + a_name_size = calculate_string_buffer(a_name);
> > + a_value_size = calculate_string_buffer(a_value);
> > + security_area_size = calculate_security_buffer(bioscfg_drv.password_data[instance].current_password);
> > + buffer_size = a_name_size + a_value_size + security_area_size;
> > +
> > + buffer = kzalloc(buffer_size, GFP_KERNEL);
> > + if (!buffer) {
> > + ret = -ENOMEM;
> > + goto out_set_attribute;
> > + }
> > +
> > + /* build variables to set */
> > + start = buffer;
> > + start = ascii_to_utf16_unicode(start, a_name);
> > + if (!start)
> > + goto out_set_attribute;
> > +
> > + start = ascii_to_utf16_unicode(start, a_value);
> > + if (!start)
> > + goto out_set_attribute;
> > +
> > + populate_security_buffer(start, bioscfg_drv.password_data[instance].current_password);
> > + ret = hp_wmi_set_bios_setting(buffer, buffer_size);
> > +
> > +
> > +out_set_attribute:
> > + kfree(buffer);
> > + mutex_unlock(&bioscfg_drv.mutex);
> > + return ret;
> > +}
> > +
> > +/*
> > + * hp_wmi_perform_query
> > + *
> > + * query: The commandtype (enum hp_wmi_commandtype)
> > + * write: The command (enum hp_wmi_command)
> > + * buffer: Buffer used as input and/or output
> > + * insize: Size of input buffer
> > + * outsize: Size of output buffer
> > + *
> > + * returns zero on success
> > + * an HP WMI query specific error code (which is positive)
> > + * -EINVAL if the query was not successful at all
> > + * -EINVAL if the output buffer size exceeds buffersize
> > + *
> > + * Note: The buffersize must at least be the maximum of the input and output
> > + * size. E.g. Battery info query is defined to have 1 byte input
> > + * and 128 byte output. The caller would do:
> > + * buffer = kzalloc(128, GFP_KERNEL);
> > + * ret = hp_wmi_perform_query(HPWMI_BATTERY_QUERY, HPWMI_READ, buffer, 1, 128)
> > + */
> > +int hp_wmi_perform_query(int query, enum hp_wmi_command command, void *buffer, int insize, int outsize)
> > +{
> > + struct acpi_buffer input, output = { ACPI_ALLOCATE_BUFFER, NULL };
> > + struct bios_return *bios_return;
> > + union acpi_object *obj = NULL;
> > + struct bios_args *args = NULL;
> > + int mid, actual_insize, actual_outsize;
> > + size_t bios_args_size;
> > + int ret;
> > +
> > + mid = encode_outsize_for_pvsz(outsize);
> > + if (WARN_ON(mid < 0))
> > + return mid;
> > +
> > + actual_insize = insize;
> > + bios_args_size = struct_size(args, data, insize);
> > + args = kmalloc(bios_args_size, GFP_KERNEL);
> > + if (!args)
> > + return -ENOMEM;
> > +
> > + input.length = bios_args_size;
> > + input.pointer = args;
> > +
> > + args->signature = 0x55434553;
> > + args->command = command;
> > + args->commandtype = query;
> > + args->datasize = insize;
> > + memcpy(args->data, buffer, flex_array_size(args, data, insize));
> > +
> > + ret = wmi_evaluate_method(HP_WMI_BIOS_GUID, 0, mid, &input, &output);
> > + bioscfg_drv.last_wmi_status = ret;
> > + if (ret)
> > + goto out_free;
> > +
> > + obj = output.pointer;
> > + if (!obj) {
> > + ret = -EINVAL;
> > + goto out_free;
> > + }
> > +
>
> You need to check the type of obj here before dereferencing
> obj as if it is a buffer.
>
> > + bios_return = (struct bios_return *)obj->buffer.pointer;
> > + ret = bios_return->return_code;
> > + bioscfg_drv.last_wmi_status = ret;
> > + if (ret) {
> > + if (ret != HPWMI_RET_UNKNOWN_COMMAND &&
> > + ret != HPWMI_RET_UNKNOWN_CMDTYPE)
> > + pr_warn("query 0x%x returned error 0x%x\n", query, ret);
> > + goto out_free;
> > + }
> > +
> > + /* Ignore output data of zero size */
> > + if (!outsize)
> > + goto out_free;
> > +
> > + actual_outsize = min(outsize, (int)(obj->buffer.length - sizeof(*bios_return)));
> > + memcpy(buffer, obj->buffer.pointer + sizeof(*bios_return), actual_outsize);
> > + memset(buffer + actual_outsize, 0, outsize - actual_outsize);
> > +
> > +out_free:
> > + kfree(obj);
> > + kfree(args);
> > + return ret;
> > +}
> > +
> > +/*
> > + * ascii_to_utf16_unicode - Convert ascii string to UTF-16 unicode
> > + *
> > + * @p: Unicode buffer address
> > + * @str: string to convert to unicode
> > + *
> > + * Returns a void pointer to the buffer containing unicode string
> > + */
> > +void *ascii_to_utf16_unicode(u16 *p, const u8 *str)
> > +{
> > + int len = strlen(str);
> > + int ret;
> > +
> > + /*
> > + * Add null character when reading an empty string
> > + */
> > + if (len == 0) {
> > + *p++ = 2;
> > + *p++ = (u8)0x00;
> > + return p;
>
> This does not match with calculate_string_buffer() which will
> return 2 for a 0 length string while you are using 4 bytes here.
>
> I guess this may also be why you need to use " " for
> auth_empty_value above, so as to avoid this bug.
>
HP BIOS expects 2 characters when an empty string is being converted
to u16 hence the reason for returning 2 instead of zero. This is an
intended behavior and needed when allocating a buffer and writing to
BIOS.
>
> > + }
> > + *p++ = len * 2;
> > + ret = utf8s_to_utf16s(str, strlen(str), UTF16_HOST_ENDIAN, p, len);
> > +
> > + if (ret < 0) {
> > + dev_err(bioscfg_drv.class_dev, "UTF16 conversion failed\n");
> > + goto ascii_to_utf16_unicode_out;
>
> You have an error here, but you don't return an error at the end of
> this function.
>
> Please for version 5 do the following:
>
> 1. Add a preparation patch which moves populate_string_buffer()
> and calculate_string_buffer() from
> drivers/platform/x86/dell/dell-wmi-sysman/sysman.c to
> drivers/platform/x86/wmi.c
>
Are you asking to change sysman.c which is a DELL specific driver?
I don't have a DELL platform to validate the changes and I will be
doing the work on HP workday. Sorry but I cannot do that.
> Renaming them to:
>
> size_t wmi_utf16_str_size(const char *str);
> ssize_t wmi_str_to_utf16_str(u16 *buffer, size_t buffer_len, const char *str);
>
> (adding these prototypes to include/linux/wmi.h)
>
I will make the changes requested but I'll wait for your response to
the previous comments regarding calculate_string_buffer()
> and make the dell-wmi-sysman code use these new helpers
>
> 2. Also use these new helpers in your own code instead
> of your own ascii_to_utf16_unicode() function
>
> > + }
> > +
> > + if ((ret * sizeof(u16)) > U16_MAX) {
> > + dev_err(bioscfg_drv.class_dev, "Error string too long\n");
> > + goto ascii_to_utf16_unicode_out;
> > + }
> > +
> > +ascii_to_utf16_unicode_out:
> > + p += len;
> > + return p;
> > +}
> > +
> > +/*
> > + * hp_wmi_set_bios_setting - Set setting's value in BIOS
> > + *
> > + * @input_buffer: Input buffer address
> > + * @input_size: Input buffer size
> > + *
> > + * Returns: Count of unicode characters written to BIOS if successful, otherwise
> > + * -ENOMEM unable to allocate memory
> > + * -EINVAL buffer not allocated or too small
> > + */
> > +int hp_wmi_set_bios_setting(void *input_buffer, int input_size)
> > +{
> > + union acpi_object *obj;
> > + struct acpi_buffer input = {input_size, input_buffer};
> > + struct acpi_buffer output = {ACPI_ALLOCATE_BUFFER, NULL};
> > + int ret = 0;
> > +
> > + ret = wmi_evaluate_method(HP_WMI_SET_BIOS_SETTING_GUID, 0, 1, &input, &output);
> > +
> > + obj = output.pointer;
> > + if (!obj)
> > + return -EINVAL;
> > +
> > + if (obj->type != ACPI_TYPE_INTEGER)
> > + ret = -EINVAL;
> > +
> > + ret = obj->integer.value;
> > +
> > + kfree(obj);
> > + return ret;
> > +}
> > +
> > +/*
> > + * set_bios_defaults() - Resets BIOS defaults
> > + *
> > + * @deftype: the type of BIOS value reset to issue.
> > + *
> > + * Resets BIOS defaults
> > + */
> > +int set_bios_defaults(u8 deftype)
> > +{
> > + return -EOPNOTSUPP;
> > +}
>
> This function is not used anywhere, please drop it.
>
> > +
> > +static int bios_attr_set_interface_probe(struct wmi_device *wdev, const void *context)
> > +{
> > + mutex_lock(&bioscfg_drv.mutex);
> > + bioscfg_drv.bios_attr_wdev = wdev;
> > + mutex_unlock(&bioscfg_drv.mutex);
> > + return 0;
> > +}
> > +
> > +static void bios_attr_set_interface_remove(struct wmi_device *wdev)
> > +{
> > + mutex_lock(&bioscfg_drv.mutex);
> > + bioscfg_drv.bios_attr_wdev = NULL;
> > + mutex_unlock(&bioscfg_drv.mutex);
> > +}
> > +
> > +static const struct wmi_device_id bios_attr_set_interface_id_table[] = {
> > + { .guid_string = HP_WMI_BIOS_GUID},
> > + { },
> > +};
> > +static struct wmi_driver bios_attr_set_interface_driver = {
> > + .driver = {
> > + .name = DRIVER_NAME
> > + },
> > + .probe = bios_attr_set_interface_probe,
> > + .remove = bios_attr_set_interface_remove,
> > + .id_table = bios_attr_set_interface_id_table,
> > +};
> > +
> > +int init_bios_attr_set_interface(void)
> > +{
> > + return wmi_driver_register(&bios_attr_set_interface_driver);
> > +}
> > +
> > +void exit_bios_attr_set_interface(void)
> > +{
> > + wmi_driver_unregister(&bios_attr_set_interface_driver);
> > +}
> > +
> > +MODULE_DEVICE_TABLE(wmi, bios_attr_set_interface_id_table);
> > diff --git a/drivers/platform/x86/hp/hp-bioscfg/bioscfg.h b/drivers/platform/x86/hp/hp-bioscfg/bioscfg.h
> > new file mode 100644
> > index 000000000000..4409481f84f2
> > --- /dev/null
> > +++ b/drivers/platform/x86/hp/hp-bioscfg/bioscfg.h
> > @@ -0,0 +1,671 @@
> > +/* SPDX-License-Identifier: GPL-2.0
> > + *
> > + * Definitions for kernel modules using hp_bioscfg driver
> > + *
> > + * Copyright (c) 2022 HP Development Company, L.P.
> > + */
> > +
> > +#ifndef _HP_BIOSCFG_H_
> > +#define _HP_BIOSCFG_H_
> > +
> > +#include <linux/wmi.h>
> > +#include <linux/types.h>
> > +#include <linux/device.h>
> > +#include <linux/module.h>
> > +#include <linux/kernel.h>
> > +#include <linux/capability.h>
> > +#include <linux/nls.h>
> > +
> > +
> > +#define DRIVER_NAME "hp-bioscfg"
> > +
> > +#define MAX_BUFF 512
> > +#define MAX_KEY_MOD 256
> > +#define MAX_PASSWD_SIZE 64
> > +#define MAX_MESSAGE_SIZE 256
> > +
> > +#define SPM_STR_DESC "Secure Platform Management"
> > +#define SPM_STR "SPM"
> > +#define SURE_START_DESC "Sure Start"
> > +#define SURE_START_STR "Sure_Start"
> > +#define SURE_ADMIN_DESC "Sure Admin"
> > +#define SURE_ADMIN_STR "Sure_Admin"
> > +#define SETUP_PASSWD "Setup Password"
> > +#define POWER_ON_PASSWD "Power-On Password"
> > +
> > +#define LANG_CODE_STR "en_US.UTF-8"
> > +#define SCHEDULE_POWER_ON "Scheduled Power-On"
> > +
> > +/* Sure Admin Functions */
> > +
> > +#define UTF_PREFIX ((unsigned char *)"<utf-16/>")
> > +#define BEAM_PREFIX ((unsigned char *)"<BEAM/>")
> > +
> > +/* mechanism - Authentication attribute */
> > +
> > +#define MAX_MECHANISM_TYPES 3
> > +
> > +enum mechanism_values {
> > + PASSWORD = 0x00,
> > + NOT_PROVISION = 0x00,
> > + SIGNING_KEY = 0x01,
> > + ENDORSEMENT_KEY = 0x02
> > +};
> > +
> > +static const char * const spm_mechanism_types[] = {
> > + "not provision",
> > + "signing-key",
> > + "endorsement-key"
> > +};
> > +
> > +static const char * const passwd_mechanism_types[] = {
> > + "password",
> > +};
> > +
> > +/* roles - Authentication attribute */
> > +enum role_values {
> > + BIOS_ADMIN = 0x00,
> > + POWER_ON = 0x01,
> > + BIOS_SPM = 0x02
> > +};
> > +
> > +static const char * const role_type[] = {
> > + "bios-admin",
> > + "power-on",
> > + "enhanced-bios-auth"
> > +};
> > +
> > +
> > +#define HP_WMI_BIOS_GUID "5FB7F034-2C63-45e9-BE91-3D44E2C707E4"
> > +
> > +#define HP_WMI_BIOS_STRING_GUID "988D08E3-68F4-4c35-AF3E-6A1B8106F83C"
> > +#define HP_WMI_BIOS_INTEGER_GUID "8232DE3D-663D-4327-A8F4-E293ADB9BF05"
> > +#define HP_WMI_BIOS_ENUMERATION_GUID "2D114B49-2DFB-4130-B8FE-4A3C09E75133"
> > +#define HP_WMI_BIOS_ORDERED_LIST_GUID "14EA9746-CE1F-4098-A0E0-7045CB4DA745"
> > +#define HP_WMI_BIOS_PASSWORD_GUID "322F2028-0F84-4901-988E-015176049E2D"
> > +#define HP_WMI_SET_BIOS_SETTING_GUID "1F4C91EB-DC5C-460b-951D-C7CB9B4B8D5E"
> > +
> > +enum hp_wmi_spm_commandtype {
> > + HPWMI_SECUREPLATFORM_GET_STATE = 0x10,
> > + HPWMI_SECUREPLATFORM_SET_KEK = 0x11,
> > + HPWMI_SECUREPLATFORM_SET_SK = 0x12,
> > +};
> > +
> > +enum hp_wmi_surestart_commandtype {
> > + HPWMI_SURESTART_GET_LOG_COUNT = 0x01,
> > + HPWMI_SURESTART_GET_LOG = 0x02,
> > +};
> > +
> > +enum hp_wmi_command {
> > + HPWMI_READ = 0x01,
> > + HPWMI_WRITE = 0x02,
> > + HPWMI_ODM = 0x03,
> > + HPWMI_SURESTART = 0x20006,
> > + HPWMI_GM = 0x20008,
> > + HPWMI_SECUREPLATFORM = 0x20010,
> > +};
> > +
> > +struct bios_return {
> > + u32 sigpass;
> > + u32 return_code;
> > +};
> > +
> > +enum hp_return_value {
> > + HPWMI_RET_WRONG_SIGNATURE = 0x02,
> > + HPWMI_RET_UNKNOWN_COMMAND = 0x03,
> > + HPWMI_RET_UNKNOWN_CMDTYPE = 0x04,
> > + HPWMI_RET_INVALID_PARAMETERS = 0x05,
> > +};
> > +
> > +enum wmi_error_values {
> > + SUCCESS = 0x00,
> > + CMD_FAILED = 0x01,
> > + INVALID_SIGN = 0x02,
> > + INVALID_CMD_VALUE = 0x03,
> > + INVALID_CMD_TYPE = 0x04,
> > + INVALID_DATA_SIZE = 0x05,
> > + INVALID_CMD_PARAM = 0x06,
> > + ENCRYP_CMD_REQUIRED = 0x07,
> > + NO_SECURE_SESSION = 0x08,
> > + SECURE_SESSION_FOUND = 0x09,
> > + SECURE_SESSION_FAILED = 0x0A,
> > + AUTH_FAILED = 0x0B,
> > + INVALID_BIOS_AUTH = 0x0E,
> > + NONCE_DID_NOT_MATCH = 0x18,
> > + GENERIC_ERROR = 0x1C,
> > + BIOS_ADMIN_POLICY_NOT_MET = 0x28,
> > + BIOS_ADMIN_NOT_SET = 0x38,
> > + P21_NO_PROVISIONED = 0x1000,
> > + P21_PROVISION_IN_PROGRESS = 0x1001,
> > + P21_IN_USE = 0x1002,
> > + HEP_NOT_ACTIVE = 0x1004,
> > + HEP_ALREADY_SET = 0x1006,
> > + HEP_CHECK_STATE = 0x1007
> > +};
> > +
> > +enum spm_features {
> > + HEP_ENABLED = 0x01,
> > + PLATFORM_RECOVERY = 0x02,
> > + ENHANCED_BIOS_AUTH_MODE = 0x04
> > +};
> > +
> > +
> > +/*
> > + * struct bios_args buffer is dynamically allocated. New WMI command types
> > + * were introduced that exceeds 128-byte data size. Changes to handle
> > + * the data size allocation scheme were kept in hp_wmi_perform_qurey function.
> > + */
> > +struct bios_args {
> > + u32 signature;
> > + u32 command;
> > + u32 commandtype;
> > + u32 datasize;
> > + u8 data[];
> > +};
> > +
> > +
> > +#pragma pack(1)
> > +struct secureplatform_provisioning_data {
> > + u8 state;
> > + u8 version[2];
> > + u8 reserved1;
> > + u32 features;
> > + u32 nonce;
> > + u8 reserved2[28];
> > + u8 sk_mod[MAX_KEY_MOD];
> > + u8 kek_mod[MAX_KEY_MOD];
> > +};
> > +
> > +#pragma pack()
> > +
> > +
> > +struct string_data {
> > + struct kobject *attr_name_kobj;
> > + u8 attribute_name[MAX_BUFF];
> > + u8 display_name[MAX_BUFF];
> > + u8 current_value[MAX_BUFF];
> > + u8 new_value[MAX_BUFF];
> > + u8 path[MAX_BUFF];
> > + u32 is_readonly;
> > + u32 display_in_ui;
> > + u32 requires_physical_presence;
> > + u32 sequence;
> > + u32 prerequisitesize;
> > + u8 prerequisites[MAX_BUFF];
> > + u32 security_level;
> > + u32 min_length;
> > + u32 max_length;
> > + u8 display_name_language_code[MAX_BUFF];
> > + u32 type;
> > +};
> > +
> > +struct integer_data {
> > + struct kobject *attr_name_kobj;
> > + u8 attribute_name[MAX_BUFF];
> > + u8 display_name[MAX_BUFF];
> > + u32 current_value;
> > + u32 new_value;
> > + u8 path[MAX_BUFF];
> > + u32 is_readonly;
> > + u32 display_in_ui;
> > + u32 requires_physical_presence;
> > + u32 sequence;
> > + u32 prerequisitesize;
> > + u8 prerequisites[MAX_BUFF];
> > + u32 security_level;
> > + u32 lower_bound;
> > + u32 upper_bound;
> > + u32 scalar_increment;
> > + u8 display_name_language_code[MAX_BUFF];
> > + u32 type;
> > +};
> > +
> > +struct enumeration_data {
> > + struct kobject *attr_name_kobj;
> > + u8 attribute_name[MAX_BUFF];
> > + u8 display_name[MAX_BUFF];
> > + u8 path[MAX_BUFF];
> > + u32 is_readonly;
> > + u32 display_in_ui;
> > + u32 requires_physical_presence;
> > + u32 sequence;
> > + u32 prerequisitesize;
> > + u8 prerequisites[MAX_BUFF];
> > + u32 security_level;
> > + u8 current_value[MAX_BUFF];
> > + u8 new_value[MAX_BUFF];
> > + u32 size;
> > + u8 possible_values[MAX_BUFF];
> > + u8 display_name_language_code[MAX_BUFF];
> > + u32 type;
> > +};
> > +
> > +struct ordered_list_data {
> > + struct kobject *attr_name_kobj;
> > + u8 attribute_name[MAX_BUFF];
> > + u8 display_name[MAX_BUFF];
> > + u8 current_value[MAX_BUFF];
> > + u8 new_value[MAX_BUFF];
> > + u8 path[MAX_BUFF];
> > + u32 is_readonly;
> > + u32 display_in_ui;
> > + u32 requires_physical_presence;
> > + u32 sequence;
> > + u32 prerequisitesize;
> > + u8 prerequisites[MAX_BUFF];
> > + u32 security_level;
> > + u32 size;
> > + u8 elements[MAX_BUFF];
> > + u8 display_name_language_code[MAX_BUFF];
> > + u32 type;
> > +};
> > +
> > +struct password_data {
> > + struct kobject *attr_name_kobj;
> > + u8 attribute_name[MAX_BUFF];
> > + u8 display_name[MAX_BUFF];
> > + u8 current_password[MAX_PASSWD_SIZE];
> > + u8 new_password[MAX_PASSWD_SIZE];
> > + u8 path[MAX_BUFF];
> > + u32 is_readonly;
> > + u32 display_in_ui;
> > + u32 requires_physical_presence;
> > + u32 sequence;
> > + u32 prerequisitesize;
> > + u8 prerequisites[MAX_BUFF];
> > + u32 security_level;
> > + u32 min_password_length;
> > + u32 max_password_length;
> > + u32 encoding_size;
> > + u8 supported_encoding[MAX_BUFF];
> > + u8 display_name_language_code[MAX_BUFF];
> > + u32 is_enabled;
> > +
> > + // 'bios-admin' 'power-on'
> > + u32 role;
> > +
> > + //'password'
> > + u32 mechanism;
> > + u32 type;
> > +};
> > +
> > +struct secure_platform_data {
> > + struct kobject *attr_name_kobj;
> > + u8 attribute_name[MAX_BUFF];
> > + u8 display_name[MAX_BUFF];
> > +
> > + u8 *endorsement_key;
> > + u8 *signing_key;
> > +
> > + u32 is_enabled;
> > + u32 mechanism;
> > + u32 type;
> > +};
> > +
> > +struct bioscfg_priv {
> > + struct wmi_device *password_attr_wdev;
> > + struct wmi_device *bios_attr_wdev;
> > + struct kset *authentication_dir_kset;
> > + struct kset *main_dir_kset;
> > + struct device *class_dev;
> > + struct string_data *string_data;
> > + u32 string_instances_count;
> > + struct integer_data *integer_data;
> > + u32 integer_instances_count;
> > + struct enumeration_data *enumeration_data;
> > + u32 enumeration_instances_count;
> > + struct ordered_list_data *ordered_list_data;
> > + u32 ordered_list_instances_count;
> > + struct password_data *password_data;
> > + u32 password_instances_count;
> > +
> > + struct kobject *sure_start_attr_kobj;
> > + struct kobject *sure_admin_attr_kobj;
> > + struct secure_platform_data spm_data;
> > +
> > + int last_wmi_status;
> > + bool pending_reboot;
> > + struct mutex mutex;
> > +};
> > +
> > +/* global structure used by multiple WMI interfaces */
> > +extern struct bioscfg_priv bioscfg_drv;
> > +
> > +enum hp_wmi_data_type {
> > + HPWMI_STRING_TYPE = 0x00,
> > + HPWMI_INTEGER_TYPE = 0x01,
> > + HPWMI_ENUMERATION_TYPE = 0x02,
> > + HPWMI_ORDERED_LIST_TYPE = 0x03,
> > + HPWMI_PASSWORD_TYPE = 0x04,
> > + HPWMI_SECURE_PLATFORM_TYPE = 0x05,
> > + HPWMI_SURE_START_TYPE = 0x06,
> > + HPWMI_SURE_ADMIN_TYPE = 0x07,
> > +};
> > +
> > +enum hp_wmi_data_elements {
> > +
> > + /* Common elements */
> > + NAME = 0,
> > + VALUE = 1,
> > + PATH = 2,
> > + IS_READONLY = 3,
> > + DISPLAY_IN_UI = 4,
> > + REQUIRES_PHYSICAL_PRESENCE = 5,
> > + SEQUENCE = 6,
> > + PREREQUISITE_SIZE = 7,
> > + PREREQUISITES = 8,
> > + SECURITY_LEVEL = 9,
> > +
> > + /* String elements */
> > + STR_MIN_LENGTH = 10,
> > + STR_MAX_LENGTH = 11,
> > +
> > + /* Integer elements */
> > + INT_LOWER_BOUND = 10,
> > + INT_UPPER_BOUND = 11,
> > + INT_SCALAR_INCREMENT = 12,
> > +
> > + /* Enumeration elements */
> > + ENUM_CURRENT_VALUE = 10,
> > + ENUM_SIZE = 11,
> > + ENUM_POSSIBLE_VALUES = 12,
> > +
> > + /* Ordered list elements */
> > + ORD_LIST_SIZE = 10,
> > + ORD_LIST_ELEMENTS = 11,
> > +
> > + /* Password elements */
> > + PSWD_MIN_LENGTH = 10,
> > + PSWD_MAX_LENGTH = 11,
> > + PSWD_SIZE = 12,
> > + PSWD_SUPPORTED_ENCODING = 13,
> > + PSWD_IS_SET = 14
> > +};
> > +
> > +
> > +static const int hp_wmi_elements_count[] = {
> > + 12, // string
> > + 13, // integer
> > + 13, // enumeration
> > + 12, // ordered list
> > + 15 // password
> > +};
> > +
> > +#define get_instance_id(type) \
> > +static int get_##type##_instance_id(struct kobject *kobj) \
> > +{ \
> > + int i; \
> > + \
> > + for (i = 0; i <= bioscfg_drv.type##_instances_count; i++) { \
> > + if (!(strcmp(kobj->name, bioscfg_drv.type##_data[i].attribute_name))) \
> > + return i; \
> > + } \
> > + return -EIO; \
> > +}
> > +
> > +#define get_instance_id_for_attribute(type) \
> > +static int get_instance_id_for_##type(char *attr_name) \
> > +{ \
> > + int i; \
> > + \
> > + for (i = 0; i < bioscfg_drv.type##_instances_count; i++) { \
> > + if (strcmp(bioscfg_drv.type##_data[i].attribute_name, attr_name) == 0) \
> > + return i; \
> > + } \
> > + return -EIO; \
> > +}
> > +
> > +#define attribute_s_property_show(name, type) \
> > +static ssize_t name##_show(struct kobject *kobj, struct kobj_attribute *attr, \
> > + char *buf) \
> > +{ \
> > + int i = get_##type##_instance_id(kobj); \
> > + if (i >= 0) \
> > + return sprintf(buf, "%s\n", bioscfg_drv.type##_data[i].name); \
>
> Please use sysfs_emit instead of sprintf for this and all the other _show() functions.
>
> > + return 0; \
> > +}
> > +/* There is no need to keep track of default and current values
> > + * separately
> > + */
> > +#define attribute_s_default_property_show(name, type, new_name) \
> > +static ssize_t name##_show(struct kobject *kobj, struct kobj_attribute *attr, \
> > + char *buf) \
> > +{ \
> > + int i = get_##type##_instance_id(kobj); \
> > + if (i >= 0) \
> > + return sprintf(buf, "%s\n", bioscfg_drv.type##_data[i].new_name); \
> > + return 0; \
> > +}
> > +
> > +#define attribute_n_default_property_show(name, type, new_name) \
> > +static ssize_t name##_show(struct kobject *kobj, struct kobj_attribute *attr, \
> > + char *buf) \
> > +{ \
> > + int i = get_##type##_instance_id(kobj); \
> > + if (i >= 0) \
> > + return sprintf(buf, "%d\n", bioscfg_drv.type##_data[i].new_name); \
> > + return 0; \
> > +}
> > +
> > +#define attribute_n_property_show(name, type) \
> > +static ssize_t name##_show(struct kobject *kobj, struct kobj_attribute *attr, \
> > + char *buf) \
> > +{ \
> > + int i = get_##type##_instance_id(kobj); \
> > + if (i >= 0) \
> > + return sprintf(buf, "%d\n", bioscfg_drv.type##_data[i].name); \
> > + return 0; \
> > +}
> > +
> > +
> > +#define attribute_property_store(curr_val, type) \
> > +static ssize_t curr_val##_store(struct kobject *kobj, \
> > + struct kobj_attribute *attr, \
> > + const char *buf, size_t count) \
> > +{ \
> > + char *p = NULL; \
> > + char *attr_value = NULL; \
> > + char *attr_name = NULL; \
> > + int i; \
> > + int ret = -EIO; \
> > + \
> > + attr_name = kstrdup(kobj->name, GFP_KERNEL); \
> > + if (!attr_name) \
> > + return -ENOMEM; \
>
> Since you don't modify attr_name (unlike attr_value) there is no need
> to make a local copy, just use kobj->name directly instead of
> the copy stored in attr_name.
>
> > + attr_value = kstrdup(buf, GFP_KERNEL); \
> > + if (!attr_value) \
> > + return -ENOMEM; \
> > + \
> > + p = memchr(attr_value, '\n', count); \
> > + if (p != NULL) \
> > + *p = '\0'; \
> > + \
> > + i = get_##type##_instance_id(kobj); \
> > + if (i >= 0) \
> > + ret = validate_##type##_input(i, attr_value); \
> > + if (!ret) \
> > + ret = hp_set_attribute(attr_name, attr_value); \
> > + if (!ret) \
> > + update_##type##_value(i); \
> > + \
> > + clear_all_passwords(); \
>
> Why ?
>
> At a minimum add a comment explaining this.
>
> > + kfree(attr_name); \
> > + kfree(attr_value); \
> > + \
> > + return ret ? ret : count; \
> > +}
> > +
> > +#define attribute_spm_n_property_show(name, type) \
> > +static ssize_t name##_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf) \
> > +{ \
> > + return sprintf(buf, "%d\n", bioscfg_drv.type##_data.name);\
> > +}
> > +
> > +#define attribute_spm_s_property_show(name, type) \
> > +static ssize_t name##_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf) \
> > +{ \
> > + return sprintf(buf, "%s\n", bioscfg_drv.type##_data.name); \
> > +}
> > +
> > +#define check_property_type(attr, prop, valuetype)\
> > + (attr##_obj[prop].type != valuetype)
> > +
> > +#define HPWMI_BINATTR_RW(_group, _name, _size) \
> > +static struct bin_attribute _group##_##_name = \
> > +__BIN_ATTR(_name, 0444 | 0200, _group##_##_name##_read, _group##_##_name##_write, _size)
> > +
> > +/*
> > + * Prototypes
> > + */
> > +union acpi_object *get_wmiobj_pointer(int instance_id, const char *guid_string);
> > +int get_instance_count(const char *guid_string);
> > +void strlcpy_attr(char *dest, char *src);
> > +void update_attribute_permissions(u32 isReadOnly, struct kobj_attribute *current_val);
> > +void friendly_user_name_update(char *path, const char *attr_name,
> > + char *attr_display, int attr_size);
> > +
> > +/* String attributes */
> > +int populate_string_buffer_data(union acpi_object *str_obj,
> > + int instance_id,
> > + struct kobject *attr_name_kobj);
> > +int populate_string_elements_from_buffer(union acpi_object *string_obj,
> > + int instance_id,
> > + enum hp_wmi_data_type type);
> > +int alloc_string_data(void);
> > +void exit_string_attributes(void);
> > +int populate_string_package_data(union acpi_object *str_obj,
> > + int instance_id,
> > + struct kobject *attr_name_kobj);
> > +int populate_string_elements_from_package(union acpi_object *str_obj,
> > + int instance_id,
> > + enum hp_wmi_data_type type);
> > +
> > +/* Integer attributes */
> > +int populate_integer_buffer_data(union acpi_object *integer_obj,
> > + int instance_id,
> > + struct kobject *attr_name_kobj);
> > +int populate_integer_elements_from_buffer(union acpi_object *integer_obj,
> > + int instance_id,
> > + enum hp_wmi_data_type type);
> > +int alloc_integer_data(void);
> > +void exit_integer_attributes(void);
> > +int populate_integer_package_data(union acpi_object *integer_obj,
> > + int instance_id,
> > + struct kobject *attr_name_kobj);
> > +int populate_integer_elements_from_package(union acpi_object *integer_obj,
> > + int instance_id,
> > + enum hp_wmi_data_type type);
> > +
> > +/* Enumeration attributes */
> > +int populate_enumeration_buffer_data(union acpi_object *enum_obj,
> > + int instance_id,
> > + struct kobject *attr_name_kobj);
> > +int populate_enumeration_elements_from_buffer(union acpi_object *enum_obj,
> > + int instance_id,
> > + enum hp_wmi_data_type type);
> > +int alloc_enumeration_data(void);
> > +void exit_enumeration_attributes(void);
> > +int populate_enumeration_package_data(union acpi_object *enum_obj,
> > + int instance_id,
> > + struct kobject *attr_name_kobj);
> > +int populate_enumeration_elements_from_package(union acpi_object *enum_obj,
> > + int instance_id,
> > + enum hp_wmi_data_type type);
> > +
> > +/* Ordered list */
> > +int populate_ordered_list_buffer_data(union acpi_object *order_obj, int instance_id,
> > + struct kobject *attr_name_kobj);
> > +int populate_ordered_list_elements_from_buffer(union acpi_object *order_obj,
> > + int instance_id,
> > + enum hp_wmi_data_type
> > + type);
> > +int alloc_ordered_list_data(void);
> > +void exit_ordered_list_attributes(void);
> > +int populate_ordered_list_package_data(union acpi_object *order_obj,
> > + int instance_id,
> > + struct kobject *attr_name_kobj);
> > +int populate_ordered_list_elements_from_package(union acpi_object *order_obj,
> > + int instance_id,
> > + enum hp_wmi_data_type type);
> > +
> > +/* Password authentication attributes */
> > +int populate_password_buffer_data(union acpi_object *password_obj,
> > + int instance_id,
> > + struct kobject *attr_name_kobj);
> > +int populate_password_elements_from_buffer(union acpi_object *password_obj,
> > + int instance_id,
> > + enum hp_wmi_data_type type);
> > +int populate_password_package_data(union acpi_object *password_obj, int instance_id,
> > + struct kobject *attr_name_kobj);
> > +int populate_password_elements_from_package(union acpi_object *password_obj,
> > + int instance_id,
> > + enum hp_wmi_data_type type);
> > +int alloc_password_data(void);
> > +int alloc_secure_platform_data(void);
> > +void exit_password_attributes(void);
> > +void exit_secure_platform_attributes(void);
> > +int populate_secure_platform_data(struct kobject *attr_name_kobj);
> > +int password_is_set(const char *auth);
> > +int check_spm_is_enabled(void);
> > +int wmi_error_and_message(int error_code, char *message);
> > +int hp_wmi_set_bios_setting(void *input_buffer, int input_size);
> > +int hp_wmi_perform_query(int query, enum hp_wmi_command command,
> > + void *buffer, int insize, int outsize);
> > +
> > +/* Sure Start attributes */
> > +void exit_sure_start_attributes(void);
> > +int populate_sure_start_data(struct kobject *attr_name_kobj);
> > +
> > +/* Sure Admin Attributes */
> > +void exit_sure_admin_attributes(void);
> > +int populate_sure_admin_data(struct kobject *attr_name_kobj);
> > +int hp_set_attribute(const char *a_name, const char *a_value);
> > +int hp_set_attribute_with_payload(const char *a_name,
> > + const char *a_value,
> > + const char *auth_payload);
> > +int update_attribute_value(char *attr_name, char *attr_value);
> > +int hp_bios_settings_fill_buffer(void);
> > +int hp_bios_settings_free_buffer(void);
> > +int hp_bios_settings_realloc_buffer(char **buf, int *buf_size,
> > + int *alloc_size);
> > +int append_read_string_attributes(char *buf, int alloc_size,
> > + int instance,
> > + enum hp_wmi_data_type type);
> > +int append_read_integer_attributes(char *buf, int alloc_size,
> > + int instance,
> > + enum hp_wmi_data_type type);
> > +int append_read_enumeration_attributes(char *buf, int alloc_size,
> > + int instance,
> > + enum hp_wmi_data_type type);
> > +int append_read_ordered_list_attributes(char *buf, int alloc_size,
> > + int instance,
> > + enum hp_wmi_data_type type);
> > +int append_read_password_attributes(char *buf, int alloc_size,
> > + int instance,
> > + enum hp_wmi_data_type type);
> > +int append_read_settings(enum hp_wmi_data_type type, char **buf,
> > + int *buf_size, int *alloc_size);
> > +int append_read_attributes(char **buf, int alloc_size,
> > + int instance, enum hp_wmi_data_type type);
> > +int set_bios_defaults(u8 defType);
> > +int get_password_instance_for_type(const char *name);
> > +int clear_all_passwords(void);
> > +int clear_passwords(const int instance);
> > +void exit_bios_attr_set_interface(void);
> > +int init_bios_attr_set_interface(void);
> > +size_t calculate_string_buffer(const char *str);
> > +size_t calculate_security_buffer(const char *authentication);
> > +void populate_security_buffer(u16 *buffer, const char *authentication);
> > +ssize_t populate_string_buffer(u16 *buffer, size_t buffer_len, const char *str);
> > +int set_new_password(const char *password_type, const char *new_password);
> > +int init_bios_attr_pass_interface(void);
> > +void exit_bios_attr_pass_interface(void);
> > +void *ascii_to_utf16_unicode(u16 *p, const u8 *str);
> > +int get_integer_from_buffer(int **buffer, int *integer);
> > +int get_string_from_buffer(u16 **buffer, char **str);
> > +int convert_hexstr_to_str(char **hex, int input_len, char **str, int *len);
> > +int convert_hexstr_to_int(char *str, int *int_value);
> > +inline int encode_outsize_for_pvsz(int outsize);
>
> Please drop the inline here, since this is just a function prototype it cannot
> be inlined.
>
> And please also drop the inline from the actual implementation, since
> that is only used in other .c files.
>
> > +
> > +#endif
> > diff --git a/drivers/platform/x86/hp/hp-bioscfg/enum-attributes.c b/drivers/platform/x86/hp/hp-bioscfg/enum-attributes.c
> > new file mode 100644
> > index 000000000000..e67e7c397c12
> > --- /dev/null
> > +++ b/drivers/platform/x86/hp/hp-bioscfg/enum-attributes.c
> > @@ -0,0 +1,521 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * Functions corresponding to enumeration type attributes under
> > + * BIOS Enumeration GUID for use with hp-bioscfg driver.
> > + *
> > + * Copyright (c) 2022 HP Development Company, L.P.
> > + */
> > +
> > +#include "bioscfg.h"
> > +
> > +get_instance_id(enumeration);
> > +
> > +static ssize_t current_value_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf)
> > +{
> > + int instance_id = get_enumeration_instance_id(kobj);
> > + union acpi_object *obj = NULL;
> > + ssize_t ret;
> > +
> > + if (instance_id < 0)
> > + return -EIO;
> > +
> > + /* need to use specific instance_id and guid combination to get right data */
> > + obj = get_wmiobj_pointer(instance_id, HP_WMI_BIOS_ENUMERATION_GUID);
> > + if (!obj)
> > + return -EIO;
>
> Why get this obj if you are not using it at all ? The attribute_property_store()
> macro updates bioscfg_drv.enumeration_data[instance_id].current_value on success,
> so I believe this function can just
>
> > +
> > + ret = snprintf(buf, PAGE_SIZE, "%s\n",
> > + bioscfg_drv.enumeration_data[instance_id].current_value);
>
> please use sysfs_emit for this
>
> > +
> > + kfree(obj);
> > + return ret;
> > +}
> > +
> > +
> > +/*
> > + * validate_enumeration_input() -
> > + * Validate input of current_value against possible values
> > + *
> > + * @instance_id: The instance on which input is validated
> > + * @buf: Input value
> > + */
> > +static int validate_enumeration_input(int instance_id, const char *buf)
> > +{
> > + char *options = NULL;
> > + char *p;
> > + int ret = 0;
> > + int found = 0;
> > +
> > + options = kstrdup(bioscfg_drv.enumeration_data[instance_id].possible_values,
> > + GFP_KERNEL);
> > +
> > + if (!options) {
> > + ret = -ENOMEM;
> > + goto exit_validate_enum_input;
> > + }
> > +
> > + /* Is it a read only attribute */
> > + if (bioscfg_drv.enumeration_data[instance_id].is_readonly) {
> > + ret = -EIO;
> > + goto exit_validate_enum_input;
> > + }
>
> Please move this check to before the kstrdup and just
> directly return -EIO; instead of doing the goto.
>
> > +
> > + while ((p = strsep(&options, ";")) != NULL) {
> > + if (!*p)
> > + continue;
> > +
> > + if (!strcasecmp(p, buf)) {
> > + found = 1;
> > + break;
> > + }
> > + }
> > +
> > + if (!found) {
> > + ret = -EINVAL;
> > + goto exit_validate_enum_input;
> > + }
> > +
> > + strscpy(bioscfg_drv.enumeration_data[instance_id].new_value,
> > + buf,
> > + sizeof(bioscfg_drv.enumeration_data[instance_id].new_value));
>
> Why store a copy of buf in new_value? This function is only called from
> the attribute_property_store() with attr_value as buf parameter.
>
> You can just also pass attr_value to update_##type##_value()
> and then have update_enumeration_value() directly store attr_value
> in current_value.
>
> Doing things this way allows removing new_value from struct enumeration_data
> all together resulting in a nice reduction in memory usage.
>
> > + /*
> > + * set pending reboot flag depending on
> > + * "RequiresPhysicalPresence" value
> > + */
> > + if (bioscfg_drv.enumeration_data[instance_id].requires_physical_presence)
> > + bioscfg_drv.pending_reboot = TRUE;
> > +
> > +exit_validate_enum_input:
> > + kfree(options);
> > + return ret;
> > +}
> > +
> > +static void update_enumeration_value(int instance_id)
> > +{
> > + strscpy(bioscfg_drv.enumeration_data[instance_id].current_value,
> > + bioscfg_drv.enumeration_data[instance_id].new_value,
> > + sizeof(bioscfg_drv.enumeration_data[instance_id].current_value));
> > +}
> > +
> > +
> > +attribute_s_property_show(display_name_language_code, enumeration);
> > +static struct kobj_attribute enumeration_display_langcode =
> > + __ATTR_RO(display_name_language_code);
> > +
> > +attribute_s_property_show(display_name, enumeration);
> > +static struct kobj_attribute enumeration_display_name =
> > + __ATTR_RO(display_name);
> > +
> > +attribute_property_store(current_value, enumeration);
> > +static struct kobj_attribute enumeration_current_val =
> > + __ATTR_RW_MODE(current_value, 0600);
> > +
> > +attribute_s_property_show(possible_values, enumeration);
> > +static struct kobj_attribute enumeration_poss_val =
> > + __ATTR_RO(possible_values);
> > +
> > +static ssize_t type_show(struct kobject *kobj, struct kobj_attribute *attr,
> > + char *buf)
> > +{
> > + return sprintf(buf, "enumeration\n");
> > +}
> > +static struct kobj_attribute enumeration_type =
> > + __ATTR_RO(type);
> > +
> > +static struct attribute *enumeration_attrs[] = {
> > + &enumeration_display_langcode.attr,
> > + &enumeration_display_name.attr,
> > + &enumeration_current_val.attr,
> > + &enumeration_poss_val.attr,
> > + &enumeration_type.attr,
> > + NULL,
> > +};
> > +
> > +static const struct attribute_group enumeration_attr_group = {
> > + .attrs = enumeration_attrs,
> > +};
> > +
> > +int alloc_enumeration_data(void)
> > +{
> > + int ret = 0;
> > +
> > + bioscfg_drv.enumeration_instances_count =
> > + get_instance_count(HP_WMI_BIOS_ENUMERATION_GUID);
> > +
> > + bioscfg_drv.enumeration_data = kcalloc(bioscfg_drv.enumeration_instances_count,
> > + sizeof(struct enumeration_data), GFP_KERNEL);
> > + if (!bioscfg_drv.enumeration_data) {
> > + bioscfg_drv.enumeration_instances_count = 0;
> > + ret = -ENOMEM;
> > + }
> > + return ret;
> > +}
> > +
> > +/*
> > + * populate_enumeration_package_data() -
> > + * Populate all properties of an instance under enumeration attribute
> > + *
> > + * @enum_obj: ACPI object with enumeration data
> > + * @instance_id: The instance to enumerate
> > + * @attr_name_kobj: The parent kernel object
> > + */
> > +int populate_enumeration_package_data(union acpi_object *enum_obj, int instance_id,
> > + struct kobject *attr_name_kobj)
> > +{
> > + char *str_value = NULL;
> > + int str_len;
> > + int ret = 0;
> > +
> > + bioscfg_drv.enumeration_data[instance_id].type = HPWMI_ENUMERATION_TYPE;
> > + bioscfg_drv.enumeration_data[instance_id].attr_name_kobj = attr_name_kobj;
> > +
> > + ret = convert_hexstr_to_str(&(enum_obj[NAME].string.pointer),
> > + enum_obj[NAME].string.length,
> > + &str_value, &str_len);
> > + if (ACPI_FAILURE(ret)) {
> > + pr_warn("Failed to populate enumeration package data. Error [0%0x]\n", ret);
> > + kfree(str_value);
> > + return ret;
> > + }
>
> You have already done this convert_hexstr_to_str call in
> hp_init_bios_attributes() and used it for the name of the passed in
> struct kobject *attr_name_kobj, so you can just use attr_name_kobj->name
> here, as you already do in the friendly_user_name_update() call below?
>
> Also you use kobj->name in the get_##type##_instance_id() macro, and the
> only reason why the enumeration_data[instance_id].attribute_name field
> is necessary is for that function.
>
> So dropping the above call and using kobj->name to intialize attribute_name
> and display_name seems to make sense here ?
>
>
>
>
> > +
> > + strscpy(bioscfg_drv.enumeration_data[instance_id].attribute_name,
> > + str_value,
> > + sizeof(bioscfg_drv.enumeration_data[instance_id].attribute_name));
> > +
> > + strscpy(bioscfg_drv.enumeration_data[instance_id].display_name,
> > + str_value,
> > + sizeof(bioscfg_drv.enumeration_data[instance_id].display_name));
> > +
> > + kfree(str_value);
> > + str_value = NULL;
>
> And then you can also drop this. Note there is no need to set str_value to NULL
> here regardless since it is a local variable which will disappear when the
> function ends.
>
> > +
> > + populate_enumeration_elements_from_package(enum_obj, instance_id, HPWMI_ENUMERATION_TYPE);
> > + update_attribute_permissions(bioscfg_drv.enumeration_data[instance_id].is_readonly,
> > + &enumeration_current_val);
> > + friendly_user_name_update(bioscfg_drv.enumeration_data[instance_id].path,
> > + attr_name_kobj->name,
> > + bioscfg_drv.enumeration_data[instance_id].display_name,
> > + sizeof(bioscfg_drv.enumeration_data[instance_id].display_name));
> > + return sysfs_create_group(attr_name_kobj, &enumeration_attr_group);
> > +}
> > +
> > +int populate_enumeration_elements_from_package(union acpi_object *enum_obj,
> > + int instance_id,
> > + enum hp_wmi_data_type type)
> > +{
> > + char *str_value = NULL;
> > + int value_len;
> > + int status = 0;
> > + u32 size = 0;
> > + u32 int_value;
> > + int elem = 0;
> > + int reqs;
> > + int eloc;
> > + int pos_values;
> > +
> > + strscpy(bioscfg_drv.enumeration_data[instance_id].display_name_language_code,
> > + LANG_CODE_STR,
> > + sizeof(bioscfg_drv.enumeration_data[instance_id].display_name_language_code));
> > +
> > + for (elem = 1, eloc = 1; elem < hp_wmi_elements_count[type]; elem++, eloc++) {
> > +
> > + switch (enum_obj[elem].type) {
> > + case ACPI_TYPE_STRING:
> > +
> > + if (PREREQUISITES != elem && ENUM_POSSIBLE_VALUES != elem) {
> > + status = convert_hexstr_to_str(&enum_obj[elem].string.pointer,
> > + enum_obj[elem].string.length,
> > + &str_value, &value_len);
> > + if (ACPI_FAILURE(status))
> > + continue;
> > +
> > + }
> > + break;
> > + case ACPI_TYPE_INTEGER:
> > + int_value = (u32)enum_obj[elem].integer.value;
> > + break;
> > + default:
> > + pr_warn("Unsupported object type [%d]\n", enum_obj[elem].type);
> > + continue;
> > + }
> > +
> > + /* stop if extra counter is greater than total number
> > + * of elements for enumeration type
> > + */
> > + if (eloc == hp_wmi_elements_count[type])
> > + goto exit_enumeration_package;
> > +
> > + /* Assign appropriate element value to corresponding field*/
> > + switch (eloc) {
> > + case VALUE:
> > + break;
> > + case PATH:
> > + strscpy(bioscfg_drv.enumeration_data[instance_id].path, str_value,
> > + sizeof(bioscfg_drv.enumeration_data[instance_id].path));
> > + break;
> > + case IS_READONLY:
> > + bioscfg_drv.enumeration_data[instance_id].is_readonly = int_value;
> > + break;
> > + case DISPLAY_IN_UI:
> > + bioscfg_drv.enumeration_data[instance_id].display_in_ui = int_value;
> > + break;
> > + case REQUIRES_PHYSICAL_PRESENCE:
> > + bioscfg_drv.enumeration_data[instance_id].requires_physical_presence = int_value;
> > + break;
> > + case SEQUENCE:
> > + bioscfg_drv.enumeration_data[instance_id].sequence = int_value;
> > + break;
> > + case PREREQUISITE_SIZE:
> > + bioscfg_drv.enumeration_data[instance_id].prerequisitesize = int_value;
> > + if (int_value > 20)
> > + pr_warn("Prerequisites size value exceeded the maximum number of elements supported or data may be malformed\n");
> > + /*
> > + * prerequisites element is omitted when
> > + * prerequisitesSize value is zero.
> > + */
> > + if (int_value == 0)
> > + eloc++;
> > + break;
> > + case PREREQUISITES:
> > + size = bioscfg_drv.enumeration_data[instance_id].prerequisitesize;
> > +
> > + for (reqs = 0; reqs < size; reqs++) {
> > + status = convert_hexstr_to_str(&enum_obj[elem].string.pointer,
> > + enum_obj[elem].string.length,
> > + &str_value, &value_len);
> > + if (ACPI_FAILURE(status))
> > + break;
> > +
> > + strlcat(bioscfg_drv.enumeration_data[instance_id].prerequisites,
> > + str_value,
> > + sizeof(bioscfg_drv.enumeration_data[instance_id].prerequisites));
> > + if (reqs != (size - 1))
> > + strlcat(bioscfg_drv.enumeration_data[instance_id].prerequisites, ";",
> > + sizeof(bioscfg_drv.enumeration_data[instance_id].prerequisites));
> > +
> > + kfree(str_value);
> > + str_value = NULL;
> > + }
> > + break;
> > +
> > + case SECURITY_LEVEL:
> > + bioscfg_drv.enumeration_data[instance_id].security_level = int_value;
> > + break;
> > +
> > + case ENUM_CURRENT_VALUE:
> > + strscpy(bioscfg_drv.enumeration_data[instance_id].current_value,
> > + str_value, sizeof(bioscfg_drv.enumeration_data[instance_id].current_value));
> > + break;
> > + case ENUM_SIZE:
> > + bioscfg_drv.enumeration_data[instance_id].size = int_value;
> > + break;
> > + case ENUM_POSSIBLE_VALUES:
> > + size = bioscfg_drv.enumeration_data[instance_id].size;
> > + for (pos_values = 0; pos_values < size; pos_values++) {
> > + status = convert_hexstr_to_str(&enum_obj[elem + pos_values].string.pointer,
> > + enum_obj[elem + pos_values].string.length,
> > + &str_value, &value_len);
> > + if (ACPI_FAILURE(status))
> > + break;
> > +
> > + strlcat(bioscfg_drv.enumeration_data[instance_id].possible_values,
> > + str_value,
> > + sizeof(bioscfg_drv.enumeration_data[instance_id].possible_values));
> > + if (pos_values < (size - 1))
> > + strlcat(bioscfg_drv.enumeration_data[instance_id].possible_values, ";",
> > + sizeof(bioscfg_drv.enumeration_data[instance_id].possible_values));
> > + kfree(str_value);
> > + str_value = NULL;
> > + }
> > + break;
> > + default:
> > + pr_warn("Invalid element: %d found in Enumeration attribute or data may be malformed\n", elem);
> > + break;
> > + }
> > +
> > + kfree(str_value);
> > + str_value = NULL;
> > + }
> > +
> > +exit_enumeration_package:
> > + kfree(str_value);
> > + str_value = NULL;
> > + return 0;
> > +}
> > +
> > +/*
> > + * populate_enumeration_buffer_data() -
> > + * Populate all properties of an instance under enumeration attribute
> > + *
> > + * @enum_obj: ACPI object with enumeration data
> > + * @instance_id: The instance to enumerate
> > + * @attr_name_kobj: The parent kernel object
> > + * @enumeration_property_count: Total properties count under enumeration type
> > + */
> > +int populate_enumeration_buffer_data(union acpi_object *enum_obj, int instance_id,
>
> Please replace:
>
> union acpi_object *enum_obj
>
> with:
>
> u16 *buffer_ptr, size_t buffer_size,
>
> for better readability, but also because actually walking obj->buffer.pointer
> feels wrong. What if some other code later wants to also check the buffer,
> but now obj->buffer.pointer is all of a sudden pointing to the end ?
>
> Also you should pass in the (remaining) size and also pass this into
> get_string_from_buffer() and into get_integer_from_buffer() and have
> them check that they do not run pass the end of the buffer.
>
> Also please adjust hp_init_bios_attributes() for it to have local:
>
> u16 *buffer_ptr;
> size_t buffer_size;
>
> variables and for it to pass them into it's get_string_from_buffer()
> call before it passes them to populate_enumeration_buffer_data()
>
> These changes have 2 goals:
>
> 1. don't modify the contents of the acpi_object. In general for
> things like walking pointers you should use a local variable
> not change the members of a passed-by-reference struct, to
> avoid surprising the caller
>
> 2. add bounds check everywhere to ensure that you don't run
> past the end of the buffer while parsing it.
>
>
> > + struct kobject *attr_name_kobj)
> > +{
> > +
> > + bioscfg_drv.enumeration_data[instance_id].type = HPWMI_ENUMERATION_TYPE;
> > + bioscfg_drv.enumeration_data[instance_id].attr_name_kobj = attr_name_kobj;
> > + strscpy(bioscfg_drv.enumeration_data[instance_id].attribute_name,
> > + attr_name_kobj->name,
> > + sizeof(bioscfg_drv.enumeration_data[instance_id].attribute_name));
> > + strscpy(bioscfg_drv.enumeration_data[instance_id].display_name,
> > + attr_name_kobj->name,
> > + sizeof(bioscfg_drv.enumeration_data[instance_id].display_name));
> > +
> > + /* Populate enumeration elements */
> > + populate_enumeration_elements_from_buffer(enum_obj, instance_id, HPWMI_ENUMERATION_TYPE);
> > + update_attribute_permissions(bioscfg_drv.enumeration_data[instance_id].is_readonly,
> > + &enumeration_current_val);
> > + friendly_user_name_update(bioscfg_drv.enumeration_data[instance_id].path,
> > + attr_name_kobj->name,
> > + bioscfg_drv.enumeration_data[instance_id].display_name,
> > + sizeof(bioscfg_drv.enumeration_data[instance_id].display_name));
> > +
> > + return sysfs_create_group(attr_name_kobj, &enumeration_attr_group);
> > +}
> > +
> > +int populate_enumeration_elements_from_buffer(union acpi_object *enum_obj,
> > + int instance_id,
> > + enum hp_wmi_data_type type)
> > +{
> > + int status;
> > + char *str = NULL;
> > + int elem;
> > + int reqs;
> > + int integer;
> > + int size = 0;
> > + int values;
> > +
> > + elem = 0;
> > +
> > + strscpy(bioscfg_drv.enumeration_data[instance_id].display_name_language_code,
> > + LANG_CODE_STR,
> > + sizeof(bioscfg_drv.enumeration_data[instance_id].display_name_language_code));
> > +
> > + for (elem = 1; elem < 3; elem++) {
> > +
> > + status = get_string_from_buffer((u16 **)&enum_obj->buffer.pointer, &str);
> > + if (ACPI_FAILURE(status))
> > + continue;
> > +
> > + switch (elem) {
> > + case VALUE:
> > + /* Skip 'Value' since 'CurrentValue' is reported. */
> > + break;
> > + case PATH:
> > + strscpy(bioscfg_drv.enumeration_data[instance_id].path,
> > + str, sizeof(bioscfg_drv.enumeration_data[instance_id].path));
> > + break;
> > + default:
> > + pr_warn("Invalid element: %d found in Enumeration attribute or data may be malformed\n", elem);
> > + break;
> > + }
> > + kfree(str);
> > + str = NULL;
> > + }
> > +
> > + for (elem = 3; elem < hp_wmi_elements_count[type]; elem++) {
> > + if (PREREQUISITES != elem && ENUM_CURRENT_VALUE != elem && ENUM_POSSIBLE_VALUES != elem)
> > + status = get_integer_from_buffer((int **)&enum_obj->buffer.pointer, (int *)&integer);
> > +
> > + if (ACPI_FAILURE(status))
> > + continue;
> > + switch (elem) {
> > + case IS_READONLY:
> > + bioscfg_drv.enumeration_data[instance_id].is_readonly = integer;
> > + break;
> > + case DISPLAY_IN_UI:
> > + bioscfg_drv.enumeration_data[instance_id].display_in_ui = integer;
> > + break;
> > + case REQUIRES_PHYSICAL_PRESENCE:
> > + bioscfg_drv.enumeration_data[instance_id].requires_physical_presence = integer;
> > + break;
> > + case SEQUENCE:
> > + bioscfg_drv.enumeration_data[instance_id].sequence = integer;
> > + break;
> > + case PREREQUISITE_SIZE:
> > + bioscfg_drv.enumeration_data[instance_id].prerequisitesize = integer;
> > + if (integer > 20)
> > + pr_warn("Prerequisites size value exceeded the maximum number of elements supported or data may be malformed\n");
> > + break;
> > + case PREREQUISITES:
> > + size = bioscfg_drv.enumeration_data[instance_id].prerequisitesize;
> > + for (reqs = 0; reqs < size; reqs++) {
> > + status = get_string_from_buffer((u16 **)&enum_obj->buffer.pointer, &str);
> > + if (ACPI_FAILURE(status))
> > + continue;
> > +
> > + strlcat(bioscfg_drv.enumeration_data[instance_id].prerequisites,
> > + str,
> > + sizeof(bioscfg_drv.enumeration_data[instance_id].prerequisites));
> > + if (reqs != (size - 1))
> > + strlcat(bioscfg_drv.enumeration_data[instance_id].prerequisites, ";",
> > + sizeof(bioscfg_drv.enumeration_data[instance_id].prerequisites));
> > + kfree(str);
> > + str = NULL;
> > + }
> > + break;
> > + case SECURITY_LEVEL:
> > + bioscfg_drv.enumeration_data[instance_id].security_level = integer;
> > + break;
> > + case ENUM_CURRENT_VALUE:
> > + status = get_string_from_buffer((u16 **)&enum_obj->buffer.pointer, &str);
> > + strscpy(bioscfg_drv.enumeration_data[instance_id].current_value,
> > + str,
> > + sizeof(bioscfg_drv.enumeration_data[instance_id].current_value));
> > + break;
> > + case ENUM_SIZE:
> > + bioscfg_drv.enumeration_data[instance_id].size = integer;
> > + break;
> > + case ENUM_POSSIBLE_VALUES:
> > + size = bioscfg_drv.enumeration_data[instance_id].size;
> > + for (values = 0; values < size; values++) {
> > + status = get_string_from_buffer((u16 **)&enum_obj->buffer.pointer, &str);
> > + if (ACPI_FAILURE(status))
> > + continue;
> > +
> > + strlcat(bioscfg_drv.enumeration_data[instance_id].possible_values,
> > + str,
> > + sizeof(bioscfg_drv.enumeration_data[instance_id].possible_values));
> > + if (values != (size - 1))
> > + strlcat(bioscfg_drv.enumeration_data[instance_id].possible_values, ";",
> > + sizeof(bioscfg_drv.enumeration_data[instance_id].possible_values));
> > + kfree(str);
> > + str = NULL;
> > + }
> > + break;
> > + default:
> > + pr_warn("Invalid element: %d found in Enumeration attribute or data may be malformed\n", elem);
> > + break;
> > + }
> > + kfree(str);
> > + str = NULL;
> > + }
> > + kfree(str);
> > + str = NULL;
> > +
> > + return 0;
> > +}
> > +
> > +/**
> > + * exit_enumeration_attributes() - Clear all attribute data
> > + *
> > + * Clears all data allocated for this group of attributes
> > + */
> > +void exit_enumeration_attributes(void)
> > +{
> > + int instance_id;
> > +
> > + for (instance_id = 0; instance_id < bioscfg_drv.enumeration_instances_count; instance_id++) {
> > + if (bioscfg_drv.enumeration_data[instance_id].attr_name_kobj)
> > + sysfs_remove_group(bioscfg_drv.enumeration_data[instance_id].attr_name_kobj,
> > + &enumeration_attr_group);
> > + }
> > + bioscfg_drv.enumeration_instances_count = 0;
> > +
> > + kfree(bioscfg_drv.enumeration_data);
> > + bioscfg_drv.enumeration_data = NULL;
> > +}
>
>
> Regards,
>
> Hans
>
