Re: [PATCH v3 2/3] platform/x86: think-lmi: Certificate support for ThinkCenter

["Ilpo Järvinen" <ilpo.jarvinen@linux.intel.com>]

On Mon, 25 Aug 2025, Mark Pearson wrote:

> ThinkCenter platforms use a different set of GUIDs along with some
> differences in implementation details for their support of
> certificate based authentication.
> 
> Update the think-lmi driver to work correctly on these platforms.
> 
> Tested on M75q Gen 5.
> 
> Signed-off-by: Kean Ren <kean0048@gmail.com>
> Signed-off-by: Mark Pearson <mpearson-lenovo@squebb.ca>
> ---
> Changes in v2:
>  - split patch up into series
> Changes in v3:
>  - Move check for no thumbprint GUID to this patch
>  - Add structure fields and missing comma
> 
>  drivers/platform/x86/lenovo/think-lmi.c | 54 ++++++++++++++++++++++---
>  drivers/platform/x86/lenovo/think-lmi.h |  1 +
>  2 files changed, 49 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/platform/x86/lenovo/think-lmi.c b/drivers/platform/x86/lenovo/think-lmi.c
> index a22d25f6d3c6..3a1cec4625e5 100644
> --- a/drivers/platform/x86/lenovo/think-lmi.c
> +++ b/drivers/platform/x86/lenovo/think-lmi.c
> @@ -119,6 +119,7 @@ MODULE_PARM_DESC(debug_support, "Enable debug command support");
>   * You must reboot the computer before the changes will take effect.
>   */
>  #define LENOVO_SET_BIOS_CERT_GUID    "26861C9F-47E9-44C4-BD8B-DFE7FA2610FE"
> +#define LENOVO_TC_SET_BIOS_CERT_GUID "955aaf7d-8bc4-4f04-90aa-97469512f167"
>  
>  /*
>   * Name: UpdateBiosCert
> @@ -128,6 +129,7 @@ MODULE_PARM_DESC(debug_support, "Enable debug command support");
>   * You must reboot the computer before the changes will take effect.
>   */
>  #define LENOVO_UPDATE_BIOS_CERT_GUID "9AA3180A-9750-41F7-B9F7-D5D3B1BAC3CE"
> +#define LENOVO_TC_UPDATE_BIOS_CERT_GUID "5f5bbbb2-c72f-4fb8-8129-228eef4fdbed"
>  
>  /*
>   * Name: ClearBiosCert
> @@ -137,6 +139,8 @@ MODULE_PARM_DESC(debug_support, "Enable debug command support");
>   * You must reboot the computer before the changes will take effect.
>   */
>  #define LENOVO_CLEAR_BIOS_CERT_GUID  "B2BC39A7-78DD-4D71-B059-A510DEC44890"
> +#define LENOVO_TC_CLEAR_BIOS_CERT_GUID  "97849cb6-cb44-42d1-a750-26a596a9eec4"
> +
>  /*
>   * Name: CertToPassword
>   * Description: Switch from certificate to password authentication.
> @@ -145,6 +149,7 @@ MODULE_PARM_DESC(debug_support, "Enable debug command support");
>   * You must reboot the computer before the changes will take effect.
>   */
>  #define LENOVO_CERT_TO_PASSWORD_GUID "0DE8590D-5510-4044-9621-77C227F5A70D"
> +#define LENOVO_TC_CERT_TO_PASSWORD_GUID "ef65480d-38c9-420d-b700-ab3d6c8ebaca"
>  
>  /*
>   * Name: SetBiosSettingCert
> @@ -153,6 +158,7 @@ MODULE_PARM_DESC(debug_support, "Enable debug command support");
>   * Format: "Item,Value,Signature"
>   */
>  #define LENOVO_SET_BIOS_SETTING_CERT_GUID  "34A008CC-D205-4B62-9E67-31DFA8B90003"
> +#define LENOVO_TC_SET_BIOS_SETTING_CERT_GUID  "19ecba3b-b318-4192-a89b-43d94bc60cea"
>  
>  /*
>   * Name: SaveBiosSettingCert
> @@ -161,6 +167,7 @@ MODULE_PARM_DESC(debug_support, "Enable debug command support");
>   * Format: "Signature"
>   */
>  #define LENOVO_SAVE_BIOS_SETTING_CERT_GUID "C050FB9D-DF5F-4606-B066-9EFC401B2551"
> +#define LENOVO_TC_SAVE_BIOS_SETTING_CERT_GUID "0afaf46f-7cca-450a-b455-a826a0bf1af5"
>  
>  /*
>   * Name: CertThumbprint
> @@ -197,6 +204,16 @@ static struct tlmi_cert_guids thinkpad_cert_guid = {
>  	.set_bios_cert = LENOVO_SET_BIOS_CERT_GUID,
>  };
>  
> +static struct tlmi_cert_guids thinkcenter_cert_guid = {
> +	.thumbprint = NULL,
> +	.set_bios_setting = LENOVO_TC_SET_BIOS_SETTING_CERT_GUID,
> +	.save_bios_setting = LENOVO_TC_SAVE_BIOS_SETTING_CERT_GUID,
> +	.cert_to_password = LENOVO_TC_CERT_TO_PASSWORD_GUID,
> +	.clear_bios_cert = LENOVO_TC_CLEAR_BIOS_CERT_GUID,
> +	.update_bios_cert = LENOVO_TC_UPDATE_BIOS_CERT_GUID,
> +	.set_bios_cert = LENOVO_TC_SET_BIOS_CERT_GUID,
> +};
> +
>  static struct tlmi_cert_guids *cert_guid = &thinkpad_cert_guid;
>  
>  static const struct tlmi_err_codes tlmi_errs[] = {
> @@ -690,6 +707,9 @@ static ssize_t cert_thumbprint(char *buf, const char *arg, int count)
>  	const union acpi_object *obj;
>  	acpi_status status;
>  
> +	if (!cert_guid->thumbprint)
> +		return -EOPNOTSUPP;
> +
>  	status = wmi_evaluate_method(cert_guid->thumbprint, 0, 0, &input, &output);
>  	if (ACPI_FAILURE(status)) {
>  		kfree(output.pointer);
> @@ -868,8 +888,16 @@ static ssize_t certificate_store(struct kobject *kobj,
>  			return -EACCES;
>  		}
>  		guid = cert_guid->set_bios_cert;
> -		/* Format: 'Certificate, password' */
> -		auth_str = cert_command(setting, new_cert, setting->password);
> +		if (tlmi_priv.thinkcenter_mode) {
> +			/* Format: 'Certificate, password, encoding, kbdlang' */
> +			auth_str = kasprintf(GFP_KERNEL, "%s,%s,%s,%s", new_cert,
> +					     setting->password,
> +					     encoding_options[setting->encoding],
> +					     setting->kbdlang);
> +		} else {
> +			/* Format: 'Certificate, password' */
> +			auth_str = cert_command(setting, new_cert, setting->password);
> +		}
>  	}
>  	kfree(new_cert);
>  	if (!auth_str)
> @@ -1605,6 +1633,16 @@ static int tlmi_analyze(struct wmi_device *wdev)
>  		wmi_has_guid(LENOVO_SAVE_BIOS_SETTING_CERT_GUID))
>  		tlmi_priv.certificate_support = true;
>  
> +	/* ThinkCenter uses different GUIDs for certificate support */
> +	if (wmi_has_guid(LENOVO_TC_SET_BIOS_CERT_GUID) &&
> +	    wmi_has_guid(LENOVO_TC_SET_BIOS_SETTING_CERT_GUID) &&
> +	    wmi_has_guid(LENOVO_TC_SAVE_BIOS_SETTING_CERT_GUID)) {
> +		tlmi_priv.certificate_support = true;
> +		tlmi_priv.thinkcenter_mode = true;
> +		cert_guid = &thinkcenter_cert_guid;

Now that this code is more readable :-), I started to wonder why this 
pointer wasn't placed into tlmi_priv?

--
 i.

> +		pr_info("ThinkCenter modified support being used\n");
> +	}
> +
>  	/*
>  	 * Try to find the number of valid settings of this machine
>  	 * and use it to create sysfs attributes.
> @@ -1750,10 +1788,14 @@ static int tlmi_analyze(struct wmi_device *wdev)
>  	}
>  
>  	if (tlmi_priv.certificate_support) {
> -		tlmi_priv.pwd_admin->cert_installed =
> -			tlmi_priv.pwdcfg.core.password_state & TLMI_CERT_SVC;
> -		tlmi_priv.pwd_system->cert_installed =
> -			tlmi_priv.pwdcfg.core.password_state & TLMI_CERT_SMC;
> +		if (tlmi_priv.thinkcenter_mode) {
> +			tlmi_priv.pwd_admin->cert_installed = tlmi_priv.pwdcfg.core.password_mode;
> +		} else {
> +			tlmi_priv.pwd_admin->cert_installed =
> +				tlmi_priv.pwdcfg.core.password_state & TLMI_CERT_SVC;
> +			tlmi_priv.pwd_system->cert_installed =
> +				tlmi_priv.pwdcfg.core.password_state & TLMI_CERT_SMC;
> +		}
>  	}
>  	return 0;
>  
> diff --git a/drivers/platform/x86/lenovo/think-lmi.h b/drivers/platform/x86/lenovo/think-lmi.h
> index 9b014644d316..c805ee312539 100644
> --- a/drivers/platform/x86/lenovo/think-lmi.h
> +++ b/drivers/platform/x86/lenovo/think-lmi.h
> @@ -109,6 +109,7 @@ struct think_lmi {
>  	enum save_mode save_mode;
>  	bool save_required;
>  	bool reboot_required;
> +	bool thinkcenter_mode;
>  
>  	struct tlmi_attr_setting *setting[TLMI_SETTINGS_COUNT];
>  	struct device *class_dev;
>