drivers/s390/crypto/pkey_base.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0
 /*
  *  pkey base: debug feature, pkey handler registry
  *
  *  Copyright IBM Corp. 2024
  */

 #define KMSG_COMPONENT "pkey"
 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt

 #include <linux/cpufeature.h>
 #include <linux/init.h>
 #include <linux/list.h>
 #include <linux/module.h>
 #include <linux/rculist.h>

 #include "pkey_base.h"

 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("IBM Corporation");
 MODULE_DESCRIPTION("s390 protected key base and api");

 /*
  * pkey debug feature
  */
 debug_info_t *pkey_dbf_info;
 EXPORT_SYMBOL(pkey_dbf_info);

 /*
  * pkey handler registry
  */

 static DEFINE_SPINLOCK(handler_list_write_lock);
 static LIST_HEAD(handler_list);

 int pkey_handler_register(struct pkey_handler *handler)
 {
 	const struct pkey_handler *h;

 	if (!handler ||
 	    !handler->is_supported_key ||
 	    !handler->is_supported_keytype)
 		return -EINVAL;

 	if (!try_module_get(handler->module))
 		return -ENXIO;

 	spin_lock(&handler_list_write_lock);

 	rcu_read_lock();
 	list_for_each_entry_rcu(h, &handler_list, list) {
 		if (h == handler) {
 			rcu_read_unlock();
 			spin_unlock(&handler_list_write_lock);
 			module_put(handler->module);
 			return -EEXIST;
 		}
 	}
 	rcu_read_unlock();

 	list_add_rcu(&handler->list, &handler_list);
 	spin_unlock(&handler_list_write_lock);
 	synchronize_rcu();

 	module_put(handler->module);

 	PKEY_DBF_INFO("%s pkey handler '%s' registered\n", __func__,
 		      handler->name ?: "<no name>");

 	return 0;
 }
 EXPORT_SYMBOL(pkey_handler_register);

 int pkey_handler_unregister(struct pkey_handler *handler)
 {
 	spin_lock(&handler_list_write_lock);
 	list_del_rcu(&handler->list);
 	INIT_LIST_HEAD_RCU(&handler->list);
 	spin_unlock(&handler_list_write_lock);
 	synchronize_rcu();

 	PKEY_DBF_INFO("%s pkey handler '%s' unregistered\n", __func__,
 		      handler->name ?: "<no name>");

 	return 0;
 }
 EXPORT_SYMBOL(pkey_handler_unregister);

 /*
  * Handler invocation functions.
  */

 const struct pkey_handler *pkey_handler_get_keybased(const u8 *key, u32 keylen)
 {
 	const struct pkey_handler *h;

 	rcu_read_lock();
 	list_for_each_entry_rcu(h, &handler_list, list) {
 		if (!try_module_get(h->module))
 			continue;
 		if (h->is_supported_key(key, keylen)) {
 			rcu_read_unlock();
 			return h;
 		}
 		module_put(h->module);
 	}
 	rcu_read_unlock();

 	return NULL;
 }
 EXPORT_SYMBOL(pkey_handler_get_keybased);

 const struct pkey_handler *pkey_handler_get_keytypebased(enum pkey_key_type kt)
 {
 	const struct pkey_handler *h;

 	rcu_read_lock();
 	list_for_each_entry_rcu(h, &handler_list, list) {
 		if (!try_module_get(h->module))
 			continue;
 		if (h->is_supported_keytype(kt)) {
 			rcu_read_unlock();
 			return h;
 		}
 		module_put(h->module);
 	}
 	rcu_read_unlock();

 	return NULL;
 }
 EXPORT_SYMBOL(pkey_handler_get_keytypebased);

 void pkey_handler_put(const struct pkey_handler *handler)
 {
 	const struct pkey_handler *h;

 	if (!handler)
 		return;

 	rcu_read_lock();
 	list_for_each_entry_rcu(h, &handler_list, list) {
 		if (h == handler) {
 			module_put(h->module);
 			break;
 		}
 	}
 	rcu_read_unlock();
 }
 EXPORT_SYMBOL(pkey_handler_put);

 int pkey_handler_key_to_protkey(const struct pkey_apqn *apqns, size_t nr_apqns,
 				const u8 *key, u32 keylen,
 				u8 *protkey, u32 *protkeylen, u32 *protkeytype)
 {
 	const struct pkey_handler *h;
 	int rc = -ENODEV;

 	h = pkey_handler_get_keybased(key, keylen);
 	if (h && h->key_to_protkey) {
 		rc = h->key_to_protkey(apqns, nr_apqns, key, keylen,
 				       protkey, protkeylen,
 				       protkeytype);
 	}
 	pkey_handler_put(h);

 	return rc;
 }
 EXPORT_SYMBOL(pkey_handler_key_to_protkey);

 /*
  * This handler invocation is special as there may be more than
  * one handler providing support for the very same key (type).
  * And the handler may not respond true on is_supported_key(),
  * so simple try and check return value here.
  */
 int pkey_handler_slowpath_key_to_protkey(const struct pkey_apqn *apqns,
 					 size_t nr_apqns,
 					 const u8 *key, u32 keylen,
 					 u8 *protkey, u32 *protkeylen,
 					 u32 *protkeytype)
 {
 	const struct pkey_handler *h, *htmp[10];
 	int i, n = 0, rc = -ENODEV;

 	rcu_read_lock();
 	list_for_each_entry_rcu(h, &handler_list, list) {
 		if (!try_module_get(h->module))
 			continue;
 		if (h->slowpath_key_to_protkey && n < ARRAY_SIZE(htmp))
 			htmp[n++] = h;
 		else
 			module_put(h->module);
 	}
 	rcu_read_unlock();

 	for (i = 0; i < n; i++) {
 		h = htmp[i];
 		if (rc)
 			rc = h->slowpath_key_to_protkey(apqns, nr_apqns,
 							key, keylen,
 							protkey, protkeylen,
 							protkeytype);
 		module_put(h->module);
 	}

 	return rc;
 }
 EXPORT_SYMBOL(pkey_handler_slowpath_key_to_protkey);

 int pkey_handler_gen_key(const struct pkey_apqn *apqns, size_t nr_apqns,
 			 u32 keytype, u32 keysubtype,
 			 u32 keybitsize, u32 flags,
 			 u8 *keybuf, u32 *keybuflen, u32 *keyinfo)
 {
 	const struct pkey_handler *h;
 	int rc = -ENODEV;

 	h = pkey_handler_get_keytypebased(keysubtype);
 	if (h && h->gen_key) {
 		rc = h->gen_key(apqns, nr_apqns, keytype, keysubtype,
 				keybitsize, flags,
 				keybuf, keybuflen, keyinfo);
 	}
 	pkey_handler_put(h);

 	return rc;
 }
 EXPORT_SYMBOL(pkey_handler_gen_key);

 int pkey_handler_clr_to_key(const struct pkey_apqn *apqns, size_t nr_apqns,
 			    u32 keytype, u32 keysubtype,
 			    u32 keybitsize, u32 flags,
 			    const u8 *clrkey, u32 clrkeylen,
 			    u8 *keybuf, u32 *keybuflen, u32 *keyinfo)
 {
 	const struct pkey_handler *h;
 	int rc = -ENODEV;

 	h = pkey_handler_get_keytypebased(keysubtype);
 	if (h && h->clr_to_key) {
 		rc = h->clr_to_key(apqns, nr_apqns, keytype, keysubtype,
 				   keybitsize, flags, clrkey, clrkeylen,
 				   keybuf, keybuflen, keyinfo);
 	}
 	pkey_handler_put(h);

 	return rc;
 }
 EXPORT_SYMBOL(pkey_handler_clr_to_key);

 int pkey_handler_verify_key(const u8 *key, u32 keylen,
 			    u16 *card, u16 *dom,
 			    u32 *keytype, u32 *keybitsize, u32 *flags)
 {
 	const struct pkey_handler *h;
 	int rc = -ENODEV;

 	h = pkey_handler_get_keybased(key, keylen);
 	if (h && h->verify_key) {
 		rc = h->verify_key(key, keylen, card, dom,
 				   keytype, keybitsize, flags);
 	}
 	pkey_handler_put(h);

 	return rc;
 }
 EXPORT_SYMBOL(pkey_handler_verify_key);

 int pkey_handler_apqns_for_key(const u8 *key, u32 keylen, u32 flags,
 			       struct pkey_apqn *apqns, size_t *nr_apqns)
 {
 	const struct pkey_handler *h;
 	int rc = -ENODEV;

 	h = pkey_handler_get_keybased(key, keylen);
 	if (h && h->apqns_for_key)
 		rc = h->apqns_for_key(key, keylen, flags, apqns, nr_apqns);
 	pkey_handler_put(h);

 	return rc;
 }
 EXPORT_SYMBOL(pkey_handler_apqns_for_key);

 int pkey_handler_apqns_for_keytype(enum pkey_key_type keysubtype,
 				   u8 cur_mkvp[32], u8 alt_mkvp[32], u32 flags,
 				   struct pkey_apqn *apqns, size_t *nr_apqns)
 {
 	const struct pkey_handler *h;
 	int rc = -ENODEV;

 	h = pkey_handler_get_keytypebased(keysubtype);
 	if (h && h->apqns_for_keytype) {
 		rc = h->apqns_for_keytype(keysubtype,
 					  cur_mkvp, alt_mkvp, flags,
 					  apqns, nr_apqns);
 	}
 	pkey_handler_put(h);

 	return rc;
 }
 EXPORT_SYMBOL(pkey_handler_apqns_for_keytype);

 void pkey_handler_request_modules(void)
 {
 #ifdef CONFIG_MODULES
 	static const char * const pkey_handler_modules[] = {
 		"pkey_cca", "pkey_ep11", "pkey_pckmo" };
 	int i;

 	for (i = 0; i < ARRAY_SIZE(pkey_handler_modules); i++) {
 		const struct pkey_handler *h;
 		bool found = false;

 		rcu_read_lock();
 		list_for_each_entry_rcu(h, &handler_list, list) {
 			if (h->module &&
 			    !strcmp(h->module->name, pkey_handler_modules[i])) {
 				found = true;
 				break;
 			}
 		}
 		rcu_read_unlock();
 		if (!found) {
 			pr_debug("request_module(%s)\n", pkey_handler_modules[i]);
 			request_module(pkey_handler_modules[i]);
 		}
 	}
 #endif
 }
 EXPORT_SYMBOL(pkey_handler_request_modules);

 /*
  * Module init
  */
 static int __init pkey_init(void)
 {
 	int rc;

 	/* init debug feature */
 	pkey_dbf_info = debug_register("pkey", 1, 1, 5 * sizeof(long));
 	debug_register_view(pkey_dbf_info, &debug_sprintf_view);
 	debug_set_level(pkey_dbf_info, 4);

 	/* the handler registry does not need any init */

 	rc = pkey_api_init();
 	if (rc)
 		debug_unregister(pkey_dbf_info);

 	return rc;
 }

 /*
  * Module exit
  */
 static void __exit pkey_exit(void)
 {
 	pkey_api_exit();
 }

 module_cpu_feature_match(S390_CPU_FEATURE_MSA, pkey_init);
 module_exit(pkey_exit);
	// SPDX-License-Identifier: GPL-2.0
	/*
	* pkey base: debug feature, pkey handler registry
	*
	* Copyright IBM Corp. 2024
	*/

	#define KMSG_COMPONENT "pkey"
	#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt

	#include <linux/cpufeature.h>
	#include <linux/init.h>
	#include <linux/list.h>
	#include <linux/module.h>
	#include <linux/rculist.h>

	#include "pkey_base.h"

	MODULE_LICENSE("GPL");
	MODULE_AUTHOR("IBM Corporation");
	MODULE_DESCRIPTION("s390 protected key base and api");

	/*
	* pkey debug feature
	*/
	debug_info_t *pkey_dbf_info;
	EXPORT_SYMBOL(pkey_dbf_info);

	/*
	* pkey handler registry
	*/

	static DEFINE_SPINLOCK(handler_list_write_lock);
	static LIST_HEAD(handler_list);

	int pkey_handler_register(struct pkey_handler *handler)
	{
	const struct pkey_handler *h;

	if (!handler \|\|
	!handler->is_supported_key \|\|
	!handler->is_supported_keytype)
	return -EINVAL;

	if (!try_module_get(handler->module))
	return -ENXIO;

	spin_lock(&handler_list_write_lock);

	rcu_read_lock();
	list_for_each_entry_rcu(h, &handler_list, list) {
	if (h == handler) {
	rcu_read_unlock();
	spin_unlock(&handler_list_write_lock);
	module_put(handler->module);
	return -EEXIST;
	}
	}
	rcu_read_unlock();

	list_add_rcu(&handler->list, &handler_list);
	spin_unlock(&handler_list_write_lock);
	synchronize_rcu();

	module_put(handler->module);

	PKEY_DBF_INFO("%s pkey handler '%s' registered\n", __func__,
	handler->name ?: "<no name>");

	return 0;
	}
	EXPORT_SYMBOL(pkey_handler_register);

	int pkey_handler_unregister(struct pkey_handler *handler)
	{
	spin_lock(&handler_list_write_lock);
	list_del_rcu(&handler->list);
	INIT_LIST_HEAD_RCU(&handler->list);
	spin_unlock(&handler_list_write_lock);
	synchronize_rcu();

	PKEY_DBF_INFO("%s pkey handler '%s' unregistered\n", __func__,
	handler->name ?: "<no name>");

	return 0;
	}
	EXPORT_SYMBOL(pkey_handler_unregister);

	/*
	* Handler invocation functions.
	*/

	const struct pkey_handler pkey_handler_get_keybased(const u8 key, u32 keylen)
	{
	const struct pkey_handler *h;

	rcu_read_lock();
	list_for_each_entry_rcu(h, &handler_list, list) {
	if (!try_module_get(h->module))
	continue;
	if (h->is_supported_key(key, keylen)) {
	rcu_read_unlock();
	return h;
	}
	module_put(h->module);
	}
	rcu_read_unlock();

	return NULL;
	}
	EXPORT_SYMBOL(pkey_handler_get_keybased);

	const struct pkey_handler *pkey_handler_get_keytypebased(enum pkey_key_type kt)
	{
	const struct pkey_handler *h;

	rcu_read_lock();
	list_for_each_entry_rcu(h, &handler_list, list) {
	if (!try_module_get(h->module))
	continue;
	if (h->is_supported_keytype(kt)) {
	rcu_read_unlock();
	return h;
	}
	module_put(h->module);
	}
	rcu_read_unlock();

	return NULL;
	}
	EXPORT_SYMBOL(pkey_handler_get_keytypebased);

	void pkey_handler_put(const struct pkey_handler *handler)
	{
	const struct pkey_handler *h;

	if (!handler)
	return;

	rcu_read_lock();
	list_for_each_entry_rcu(h, &handler_list, list) {
	if (h == handler) {
	module_put(h->module);
	break;
	}
	}
	rcu_read_unlock();
	}
	EXPORT_SYMBOL(pkey_handler_put);

	int pkey_handler_key_to_protkey(const struct pkey_apqn *apqns, size_t nr_apqns,
	const u8 *key, u32 keylen,
	u8 protkey, u32 protkeylen, u32 *protkeytype)
	{
	const struct pkey_handler *h;
	int rc = -ENODEV;

	h = pkey_handler_get_keybased(key, keylen);
	if (h && h->key_to_protkey) {
	rc = h->key_to_protkey(apqns, nr_apqns, key, keylen,
	protkey, protkeylen,
	protkeytype);
	}
	pkey_handler_put(h);

	return rc;
	}
	EXPORT_SYMBOL(pkey_handler_key_to_protkey);

	/*
	* This handler invocation is special as there may be more than
	* one handler providing support for the very same key (type).
	* And the handler may not respond true on is_supported_key(),
	* so simple try and check return value here.
	*/
	int pkey_handler_slowpath_key_to_protkey(const struct pkey_apqn *apqns,
	size_t nr_apqns,
	const u8 *key, u32 keylen,
	u8 protkey, u32 protkeylen,
	u32 *protkeytype)
	{
	const struct pkey_handler h, htmp[10];
	int i, n = 0, rc = -ENODEV;

	rcu_read_lock();
	list_for_each_entry_rcu(h, &handler_list, list) {
	if (!try_module_get(h->module))
	continue;
	if (h->slowpath_key_to_protkey && n < ARRAY_SIZE(htmp))
	htmp[n++] = h;
	else
	module_put(h->module);
	}
	rcu_read_unlock();

	for (i = 0; i < n; i++) {
	h = htmp[i];
	if (rc)
	rc = h->slowpath_key_to_protkey(apqns, nr_apqns,
	key, keylen,
	protkey, protkeylen,
	protkeytype);
	module_put(h->module);
	}

	return rc;
	}
	EXPORT_SYMBOL(pkey_handler_slowpath_key_to_protkey);

	int pkey_handler_gen_key(const struct pkey_apqn *apqns, size_t nr_apqns,
	u32 keytype, u32 keysubtype,
	u32 keybitsize, u32 flags,
	u8 keybuf, u32 keybuflen, u32 *keyinfo)
	{
	const struct pkey_handler *h;
	int rc = -ENODEV;

	h = pkey_handler_get_keytypebased(keysubtype);
	if (h && h->gen_key) {
	rc = h->gen_key(apqns, nr_apqns, keytype, keysubtype,
	keybitsize, flags,
	keybuf, keybuflen, keyinfo);
	}
	pkey_handler_put(h);

	return rc;
	}
	EXPORT_SYMBOL(pkey_handler_gen_key);

	int pkey_handler_clr_to_key(const struct pkey_apqn *apqns, size_t nr_apqns,
	u32 keytype, u32 keysubtype,
	u32 keybitsize, u32 flags,
	const u8 *clrkey, u32 clrkeylen,
	u8 keybuf, u32 keybuflen, u32 *keyinfo)
	{
	const struct pkey_handler *h;
	int rc = -ENODEV;

	h = pkey_handler_get_keytypebased(keysubtype);
	if (h && h->clr_to_key) {
	rc = h->clr_to_key(apqns, nr_apqns, keytype, keysubtype,
	keybitsize, flags, clrkey, clrkeylen,
	keybuf, keybuflen, keyinfo);
	}
	pkey_handler_put(h);

	return rc;
	}
	EXPORT_SYMBOL(pkey_handler_clr_to_key);

	int pkey_handler_verify_key(const u8 *key, u32 keylen,
	u16 card, u16 dom,
	u32 keytype, u32 keybitsize, u32 *flags)
	{
	const struct pkey_handler *h;
	int rc = -ENODEV;

	h = pkey_handler_get_keybased(key, keylen);
	if (h && h->verify_key) {
	rc = h->verify_key(key, keylen, card, dom,
	keytype, keybitsize, flags);
	}
	pkey_handler_put(h);

	return rc;
	}
	EXPORT_SYMBOL(pkey_handler_verify_key);

	int pkey_handler_apqns_for_key(const u8 *key, u32 keylen, u32 flags,
	struct pkey_apqn apqns, size_t nr_apqns)
	{
	const struct pkey_handler *h;
	int rc = -ENODEV;

	h = pkey_handler_get_keybased(key, keylen);
	if (h && h->apqns_for_key)
	rc = h->apqns_for_key(key, keylen, flags, apqns, nr_apqns);
	pkey_handler_put(h);

	return rc;
	}
	EXPORT_SYMBOL(pkey_handler_apqns_for_key);

	int pkey_handler_apqns_for_keytype(enum pkey_key_type keysubtype,
	u8 cur_mkvp[32], u8 alt_mkvp[32], u32 flags,
	struct pkey_apqn apqns, size_t nr_apqns)
	{
	const struct pkey_handler *h;
	int rc = -ENODEV;

	h = pkey_handler_get_keytypebased(keysubtype);
	if (h && h->apqns_for_keytype) {
	rc = h->apqns_for_keytype(keysubtype,
	cur_mkvp, alt_mkvp, flags,
	apqns, nr_apqns);
	}
	pkey_handler_put(h);

	return rc;
	}
	EXPORT_SYMBOL(pkey_handler_apqns_for_keytype);

	void pkey_handler_request_modules(void)
	{
	#ifdef CONFIG_MODULES
	static const char * const pkey_handler_modules[] = {
	"pkey_cca", "pkey_ep11", "pkey_pckmo" };
	int i;

	for (i = 0; i < ARRAY_SIZE(pkey_handler_modules); i++) {
	const struct pkey_handler *h;
	bool found = false;

	rcu_read_lock();
	list_for_each_entry_rcu(h, &handler_list, list) {
	if (h->module &&
	!strcmp(h->module->name, pkey_handler_modules[i])) {
	found = true;
	break;
	}
	}
	rcu_read_unlock();
	if (!found) {
	pr_debug("request_module(%s)\n", pkey_handler_modules[i]);
	request_module(pkey_handler_modules[i]);
	}
	}
	#endif
	}
	EXPORT_SYMBOL(pkey_handler_request_modules);

	/*
	* Module init
	*/
	static int __init pkey_init(void)
	{
	int rc;

	/* init debug feature */
	pkey_dbf_info = debug_register("pkey", 1, 1, 5 * sizeof(long));
	debug_register_view(pkey_dbf_info, &debug_sprintf_view);
	debug_set_level(pkey_dbf_info, 4);

	/* the handler registry does not need any init */

	rc = pkey_api_init();
	if (rc)
	debug_unregister(pkey_dbf_info);

	return rc;
	}

	/*
	* Module exit
	*/
	static void __exit pkey_exit(void)
	{
	pkey_api_exit();
	}

	module_cpu_feature_match(S390_CPU_FEATURE_MSA, pkey_init);
	module_exit(pkey_exit);