Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 579e1acb authored by Jason Baron's avatar Jason Baron Committed by Ingo Molnar
Browse files

jump_label: Provide a self-test 



Signed-off-by: default avatarJason Baron <jbaron@akamai.com>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: benh@kernel.crashing.org
Cc: bp@alien8.de
Cc: davem@davemloft.net
Cc: ddaney@caviumnetworks.com
Cc: heiko.carstens@de.ibm.com
Cc: linux-kernel@vger.kernel.org
Cc: liuj97@gmail.com
Cc: luto@amacapital.net
Cc: michael@ellerman.id.au
Cc: rabin@rab.in
Cc: ralf@linux-mips.org
Cc: rostedt@goodmis.org
Cc: shuahkh@osg.samsung.com
Cc: vbabka@suse.cz
Cc: will.deacon@arm.com
Link: http://lkml.kernel.org/r/0c091ecebd78a879ed8a71835d205a691a75ab4e.1438227999.git.jbaron@akamai.com


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent ed79e946

lib/Kconfig.debug

+9 −0
Original line number Diff line number Diff line
@@ -1841,6 +1841,15 @@ config MEMTEST 
	        memtest=17, mean do 17 test patterns.

	  If you are unsure how to answer this question, answer N.



config TEST_JUMP_LABEL

	tristate "Test jump label"

	default n

	depends on m

	help

	  Test jump labels.



	  If unsure, say N.



source "samples/Kconfig"



source "lib/Kconfig.kgdb"

lib/Makefile

+2 −0
Original line number Diff line number Diff line
@@ -39,6 +39,8 @@ obj-$(CONFIG_TEST_KSTRTOX) += test-kstrtox.o 
obj-$(CONFIG_TEST_LKM) += test_module.o

obj-$(CONFIG_TEST_RHASHTABLE) += test_rhashtable.o

obj-$(CONFIG_TEST_USER_COPY) += test_user_copy.o

obj-$(CONFIG_TEST_JUMP_LABEL) += test_jump_label.o

obj-$(CONFIG_TEST_JUMP_LABEL) += test_jump_label_base.o



ifeq ($(CONFIG_DEBUG_KOBJECT),y)

CFLAGS_kobject.o += -DDEBUG

lib/test_jump_label.c

0 → 100644
+225 −0
Original line number Diff line number Diff line 
/*

 * Kernel module for testing jump labels.

 *

 * Copyright 2015 Akamai Technologies Inc. All Rights Reserved

 *

 * Authors:

 *      Jason Baron       <jbaron@akamai.com>

 *

 * This software is licensed under the terms of the GNU General Public

 * License version 2, as published by the Free Software Foundation, and

 * may be copied, distributed, and modified under those terms.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 */



#include <linux/module.h>

#include <linux/jump_label.h>



/* old keys */

struct static_key old_true_key = STATIC_KEY_INIT_TRUE;

struct static_key old_false_key = STATIC_KEY_INIT_FALSE;



/* new api */

DEFINE_STATIC_KEY_TRUE(true_key);

DEFINE_STATIC_KEY_FALSE(false_key);



/* external */

extern struct static_key base_old_true_key;

extern struct static_key base_inv_old_true_key;

extern struct static_key base_old_false_key;

extern struct static_key base_inv_old_false_key;



/* new api */

extern struct static_key_true base_true_key;

extern struct static_key_true base_inv_true_key;

extern struct static_key_false base_false_key;

extern struct static_key_false base_inv_false_key;





struct test_branch {

	bool init_state;

	struct static_key *key;

	bool (*test_key)(void);

};



#define test_key_func(key, branch)	\

({bool func(void) { return branch(key); } func;	})



static void invert_key(struct static_key *key)

{

	if (static_key_enabled(key))

		static_key_disable(key);

	else

		static_key_enable(key);

}



static void invert_keys(struct test_branch *branches, int size)

{

	struct static_key *previous = NULL;

	int i;



	for (i = 0; i < size; i++) {

		if (previous != branches[i].key) {

			invert_key(branches[i].key);

			previous = branches[i].key;

		}

	}

}



int verify_branches(struct test_branch *branches, int size, bool invert)

{

	int i;

	bool ret, init;



	for (i = 0; i < size; i++) {

		ret = static_key_enabled(branches[i].key);

		init = branches[i].init_state;

		if (ret != (invert ? !init : init))

			return -EINVAL;

		ret = branches[i].test_key();

		if (static_key_enabled(branches[i].key)) {

			if (!ret)

				return -EINVAL;

		} else {

			if (ret)

				return -EINVAL;

		}

	}

	return 0;

}



static int __init test_jump_label_init(void)

{

	int ret;

	int size;



	struct test_branch jump_label_tests[] = {

		/* internal keys - old keys */

		{

			.init_state = true,

			.key = &old_true_key,

			.test_key = test_key_func(&old_true_key, static_key_true),

		},

		{

			.init_state = false,

			.key = &old_false_key,

			.test_key = test_key_func(&old_false_key, static_key_false),

		},

		/* internal keys - new keys */

		{

			.init_state = true,

			.key = &true_key.key,

			.test_key = test_key_func(&true_key, static_branch_likely),

		},

		{

			.init_state = true,

			.key = &true_key.key,

			.test_key = test_key_func(&true_key, static_branch_unlikely),

		},

		{

			.init_state = false,

			.key = &false_key.key,

			.test_key = test_key_func(&false_key, static_branch_likely),

		},

		{

			.init_state = false,

			.key = &false_key.key,

			.test_key = test_key_func(&false_key, static_branch_unlikely),

		},

		/* external keys - old keys */

		{

			.init_state = true,

			.key = &base_old_true_key,

			.test_key = test_key_func(&base_old_true_key, static_key_true),

		},

		{

			.init_state = false,

			.key = &base_inv_old_true_key,

			.test_key = test_key_func(&base_inv_old_true_key, static_key_true),

		},

		{

			.init_state = false,

			.key = &base_old_false_key,

			.test_key = test_key_func(&base_old_false_key, static_key_false),

		},

		{

			.init_state = true,

			.key = &base_inv_old_false_key,

			.test_key = test_key_func(&base_inv_old_false_key, static_key_false),

		},

		/* external keys - new keys */

		{

			.init_state = true,

			.key = &base_true_key.key,

			.test_key = test_key_func(&base_true_key, static_branch_likely),

		},

		{

			.init_state = true,

			.key = &base_true_key.key,

			.test_key = test_key_func(&base_true_key, static_branch_unlikely),

		},

		{

			.init_state = false,

			.key = &base_inv_true_key.key,

			.test_key = test_key_func(&base_inv_true_key, static_branch_likely),

		},

		{

			.init_state = false,

			.key = &base_inv_true_key.key,

			.test_key = test_key_func(&base_inv_true_key, static_branch_unlikely),

		},

		{

			.init_state = false,

			.key = &base_false_key.key,

			.test_key = test_key_func(&base_false_key, static_branch_likely),

		},

		{

			.init_state = false,

			.key = &base_false_key.key,

			.test_key = test_key_func(&base_false_key, static_branch_unlikely),

		},

		{

			.init_state = true,

			.key = &base_inv_false_key.key,

			.test_key = test_key_func(&base_inv_false_key, static_branch_likely),

		},

		{

			.init_state = true,

			.key = &base_inv_false_key.key,

			.test_key = test_key_func(&base_inv_false_key, static_branch_unlikely),

		},

	};



	size = ARRAY_SIZE(jump_label_tests);



	ret = verify_branches(jump_label_tests, size, false);

	if (ret)

		goto out;



	invert_keys(jump_label_tests, size);

	ret = verify_branches(jump_label_tests, size, true);

	if (ret)

		goto out;



	invert_keys(jump_label_tests, size);

	ret = verify_branches(jump_label_tests, size, false);

	if (ret)

		goto out;

	return 0;

out:

	return ret;

}



static void __exit test_jump_label_exit(void)

{

}



module_init(test_jump_label_init);

module_exit(test_jump_label_exit);



MODULE_AUTHOR("Jason Baron <jbaron@akamai.com>");

MODULE_LICENSE("GPL");

lib/test_jump_label_base.c

0 → 100644
+68 −0
Original line number Diff line number Diff line 
/*

 * Kernel module for testing jump labels.

 *

 * Copyright 2015 Akamai Technologies Inc. All Rights Reserved

 *

 * Authors:

 *      Jason Baron       <jbaron@akamai.com>

 *

 * This software is licensed under the terms of the GNU General Public

 * License version 2, as published by the Free Software Foundation, and

 * may be copied, distributed, and modified under those terms.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 */



#include <linux/module.h>

#include <linux/jump_label.h>



/* old keys */

struct static_key base_old_true_key = STATIC_KEY_INIT_TRUE;

EXPORT_SYMBOL_GPL(base_old_true_key);

struct static_key base_inv_old_true_key = STATIC_KEY_INIT_TRUE;

EXPORT_SYMBOL_GPL(base_inv_old_true_key);

struct static_key base_old_false_key = STATIC_KEY_INIT_FALSE;

EXPORT_SYMBOL_GPL(base_old_false_key);

struct static_key base_inv_old_false_key = STATIC_KEY_INIT_FALSE;

EXPORT_SYMBOL_GPL(base_inv_old_false_key);



/* new keys */

DEFINE_STATIC_KEY_TRUE(base_true_key);

EXPORT_SYMBOL_GPL(base_true_key);

DEFINE_STATIC_KEY_TRUE(base_inv_true_key);

EXPORT_SYMBOL_GPL(base_inv_true_key);

DEFINE_STATIC_KEY_FALSE(base_false_key);

EXPORT_SYMBOL_GPL(base_false_key);

DEFINE_STATIC_KEY_FALSE(base_inv_false_key);

EXPORT_SYMBOL_GPL(base_inv_false_key);



static void invert_key(struct static_key *key)

{

	if (static_key_enabled(key))

		static_key_disable(key);

	else

		static_key_enable(key);

}



static int __init test_jump_label_base_init(void)

{

	invert_key(&base_inv_old_true_key);

	invert_key(&base_inv_old_false_key);

	invert_key(&base_inv_true_key.key);

	invert_key(&base_inv_false_key.key);



	return 0;

}



static void __exit test_jump_label_base_exit(void)

{

}



module_init(test_jump_label_base_init);

module_exit(test_jump_label_base_exit);



MODULE_AUTHOR("Jason Baron <jbaron@akamai.com>");

MODULE_LICENSE("GPL");

tools/testing/selftests/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -20,6 +20,7 @@ ifneq (1, $(quicktest)) 
TARGETS += timers

endif

TARGETS += user

TARGETS += jumplabel

TARGETS += vm

TARGETS += x86

#Please keep the TARGETS list alphabetically sorted