Commit 50a466bf authored by Andrew Donnellan's avatar Andrew Donnellan Committed by Michael Ellerman
Browse files

powerpc/secvar: Allow backend to populate static list of variable names 



Currently, the list of variables is populated by calling
secvar_ops->get_next() repeatedly, which is explicitly modelled on the
OPAL API (including the keylen parameter).

For the upcoming PLPKS backend, we have a static list of variable names.
It is messy to fit that into get_next(), so instead, let the backend put
a NULL-terminated array of variable names into secvar_ops->var_names,
which will be used if get_next() is undefined.

Signed-off-by: default avatarAndrew Donnellan <ajd@linux.ibm.com>
Signed-off-by: default avatarRussell Currey <ruscur@russell.cc>
Reviewed-by: default avatarStefan Berger <stefanb@linux.ibm.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20230210080401.345462-12-ajd@linux.ibm.com
parent 86b6c0ae

arch/powerpc/include/asm/secvar.h

+4 −0
Original line number Diff line number Diff line
@@ -21,6 +21,10 @@ struct secvar_operations { 
	ssize_t (*format)(char *buf, size_t bufsize);

	int (*max_size)(u64 *max_size);

	const struct attribute **config_attrs;



	// NULL-terminated array of fixed variable names

	// Only used if get_next() isn't provided

	const char * const *var_names;

};



#ifdef CONFIG_PPC_SECURE_BOOT

arch/powerpc/kernel/secvar-sysfs.c

+48 −21
Original line number Diff line number Diff line
@@ -157,9 +157,31 @@ static int secvar_sysfs_config(struct kobject *kobj) 
	return 0;

}



static int secvar_sysfs_load(void)

static int add_var(const char *name)

{

	struct kobject *kobj;

	int rc;



	kobj = kzalloc(sizeof(*kobj), GFP_KERNEL);

	if (!kobj)

		return -ENOMEM;



	kobject_init(kobj, &secvar_ktype);



	rc = kobject_add(kobj, &secvar_kset->kobj, "%s", name);

	if (rc) {

		pr_warn("kobject_add error %d for attribute: %s\n", rc,

			name);

		kobject_put(kobj);

		return rc;

	}



	kobject_uevent(kobj, KOBJ_ADD);

	return 0;

}



static int secvar_sysfs_load(void)

{

	u64 namesize = 0;

	char *name;

	int rc;
@@ -179,29 +201,26 @@ static int secvar_sysfs_load(void) 
			break;

		}



		kobj = kzalloc(sizeof(*kobj), GFP_KERNEL);

		if (!kobj) {

			rc = -ENOMEM;

			break;

		}



		kobject_init(kobj, &secvar_ktype);

		rc = add_var(name);

	} while (!rc);



		rc = kobject_add(kobj, &secvar_kset->kobj, "%s", name);

		if (rc) {

			pr_warn("kobject_add error %d for attribute: %s\n", rc,

				name);

			kobject_put(kobj);

			kobj = NULL;

	kfree(name);

	return rc;

}



		if (kobj)

			kobject_uevent(kobj, KOBJ_ADD);



	} while (!rc);

static int secvar_sysfs_load_static(void)

{

	const char * const *name_ptr = secvar_ops->var_names;

	int rc;



	kfree(name);

	while (*name_ptr) {

		rc = add_var(*name_ptr);

		if (rc)

			return rc;

		name_ptr++;

	}



	return 0;

}



static int secvar_sysfs_init(void)
@@ -245,7 +264,15 @@ static int secvar_sysfs_init(void) 
		goto err;

	}



	secvar_sysfs_load();

	if (secvar_ops->get_next)

		rc = secvar_sysfs_load();

	else

		rc = secvar_sysfs_load_static();



	if (rc) {

		pr_err("Failed to create variable attributes\n");

		goto err;

	}



	return 0;

err: