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almostivanIngo Molnar
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Ingo Molnar
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jump_label: Provide a self-test
Signed-off-by: Jason Baron <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Cc: Andrew Morton <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Paul E. McKenney <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Link: http://lkml.kernel.org/r/0c091ecebd78a879ed8a71835d205a691a75ab4e.1438227999.git.jbaron@akamai.com Signed-off-by: Ingo Molnar <[email protected]>
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‎lib/Kconfig.debug

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Original file line numberDiff line numberDiff line change
@@ -1841,6 +1841,15 @@ config MEMTEST
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memtest=17, mean do 17 test patterns.
18421842
If you are unsure how to answer this question, answer N.
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1844+
config TEST_JUMP_LABEL
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tristate "Test jump label"
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default n
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depends on m
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help
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Test jump labels.
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If unsure, say N.
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18441853
source "samples/Kconfig"
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source "lib/Kconfig.kgdb"

‎lib/Makefile

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@@ -39,6 +39,8 @@ obj-$(CONFIG_TEST_KSTRTOX) += test-kstrtox.o
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obj-$(CONFIG_TEST_LKM) += test_module.o
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obj-$(CONFIG_TEST_RHASHTABLE) += test_rhashtable.o
4141
obj-$(CONFIG_TEST_USER_COPY) += test_user_copy.o
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obj-$(CONFIG_TEST_JUMP_LABEL) += test_jump_label.o
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obj-$(CONFIG_TEST_JUMP_LABEL) += test_jump_label_base.o
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4345
ifeq ($(CONFIG_DEBUG_KOBJECT),y)
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CFLAGS_kobject.o += -DDEBUG

‎lib/test_jump_label.c

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/*
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* Kernel module for testing jump labels.
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*
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* Copyright 2015 Akamai Technologies Inc. All Rights Reserved
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*
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* Authors:
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* Jason Baron <[email protected]>
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*
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* This software is licensed under the terms of the GNU General Public
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* License version 2, as published by the Free Software Foundation, and
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* may be copied, distributed, and modified under those terms.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*/
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#include <linux/module.h>
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#include <linux/jump_label.h>
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/* old keys */
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struct static_key old_true_key = STATIC_KEY_INIT_TRUE;
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struct static_key old_false_key = STATIC_KEY_INIT_FALSE;
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/* new api */
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DEFINE_STATIC_KEY_TRUE(true_key);
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DEFINE_STATIC_KEY_FALSE(false_key);
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/* external */
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extern struct static_key base_old_true_key;
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extern struct static_key base_inv_old_true_key;
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extern struct static_key base_old_false_key;
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extern struct static_key base_inv_old_false_key;
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/* new api */
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extern struct static_key_true base_true_key;
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extern struct static_key_true base_inv_true_key;
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extern struct static_key_false base_false_key;
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extern struct static_key_false base_inv_false_key;
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struct test_branch {
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bool init_state;
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struct static_key *key;
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bool (*test_key)(void);
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};
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#define test_key_func(key, branch) \
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({bool func(void) { return branch(key); } func; })
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static void invert_key(struct static_key *key)
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{
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if (static_key_enabled(key))
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static_key_disable(key);
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else
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static_key_enable(key);
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}
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static void invert_keys(struct test_branch *branches, int size)
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{
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struct static_key *previous = NULL;
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int i;
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for (i = 0; i < size; i++) {
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if (previous != branches[i].key) {
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invert_key(branches[i].key);
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previous = branches[i].key;
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}
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}
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}
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int verify_branches(struct test_branch *branches, int size, bool invert)
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{
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int i;
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bool ret, init;
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for (i = 0; i < size; i++) {
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ret = static_key_enabled(branches[i].key);
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init = branches[i].init_state;
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if (ret != (invert ? !init : init))
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return -EINVAL;
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ret = branches[i].test_key();
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if (static_key_enabled(branches[i].key)) {
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if (!ret)
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return -EINVAL;
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} else {
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if (ret)
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return -EINVAL;
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}
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}
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return 0;
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}
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static int __init test_jump_label_init(void)
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{
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int ret;
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int size;
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struct test_branch jump_label_tests[] = {
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/* internal keys - old keys */
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{
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.init_state = true,
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.key = &old_true_key,
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.test_key = test_key_func(&old_true_key, static_key_true),
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},
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{
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.init_state = false,
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.key = &old_false_key,
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.test_key = test_key_func(&old_false_key, static_key_false),
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},
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/* internal keys - new keys */
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{
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.init_state = true,
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.key = &true_key.key,
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.test_key = test_key_func(&true_key, static_branch_likely),
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},
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{
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.init_state = true,
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.key = &true_key.key,
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.test_key = test_key_func(&true_key, static_branch_unlikely),
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},
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{
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.init_state = false,
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.key = &false_key.key,
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.test_key = test_key_func(&false_key, static_branch_likely),
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},
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{
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.init_state = false,
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.key = &false_key.key,
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.test_key = test_key_func(&false_key, static_branch_unlikely),
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},
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/* external keys - old keys */
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{
135+
.init_state = true,
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.key = &base_old_true_key,
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.test_key = test_key_func(&base_old_true_key, static_key_true),
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},
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{
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.init_state = false,
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.key = &base_inv_old_true_key,
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.test_key = test_key_func(&base_inv_old_true_key, static_key_true),
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},
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{
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.init_state = false,
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.key = &base_old_false_key,
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.test_key = test_key_func(&base_old_false_key, static_key_false),
148+
},
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{
150+
.init_state = true,
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.key = &base_inv_old_false_key,
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.test_key = test_key_func(&base_inv_old_false_key, static_key_false),
153+
},
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/* external keys - new keys */
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{
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.init_state = true,
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.key = &base_true_key.key,
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.test_key = test_key_func(&base_true_key, static_branch_likely),
159+
},
160+
{
161+
.init_state = true,
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.key = &base_true_key.key,
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.test_key = test_key_func(&base_true_key, static_branch_unlikely),
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},
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{
166+
.init_state = false,
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.key = &base_inv_true_key.key,
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.test_key = test_key_func(&base_inv_true_key, static_branch_likely),
169+
},
170+
{
171+
.init_state = false,
172+
.key = &base_inv_true_key.key,
173+
.test_key = test_key_func(&base_inv_true_key, static_branch_unlikely),
174+
},
175+
{
176+
.init_state = false,
177+
.key = &base_false_key.key,
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.test_key = test_key_func(&base_false_key, static_branch_likely),
179+
},
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{
181+
.init_state = false,
182+
.key = &base_false_key.key,
183+
.test_key = test_key_func(&base_false_key, static_branch_unlikely),
184+
},
185+
{
186+
.init_state = true,
187+
.key = &base_inv_false_key.key,
188+
.test_key = test_key_func(&base_inv_false_key, static_branch_likely),
189+
},
190+
{
191+
.init_state = true,
192+
.key = &base_inv_false_key.key,
193+
.test_key = test_key_func(&base_inv_false_key, static_branch_unlikely),
194+
},
195+
};
196+
197+
size = ARRAY_SIZE(jump_label_tests);
198+
199+
ret = verify_branches(jump_label_tests, size, false);
200+
if (ret)
201+
goto out;
202+
203+
invert_keys(jump_label_tests, size);
204+
ret = verify_branches(jump_label_tests, size, true);
205+
if (ret)
206+
goto out;
207+
208+
invert_keys(jump_label_tests, size);
209+
ret = verify_branches(jump_label_tests, size, false);
210+
if (ret)
211+
goto out;
212+
return 0;
213+
out:
214+
return ret;
215+
}
216+
217+
static void __exit test_jump_label_exit(void)
218+
{
219+
}
220+
221+
module_init(test_jump_label_init);
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module_exit(test_jump_label_exit);
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MODULE_AUTHOR("Jason Baron <[email protected]>");
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MODULE_LICENSE("GPL");

‎lib/test_jump_label_base.c

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@@ -0,0 +1,68 @@
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/*
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* Kernel module for testing jump labels.
3+
*
4+
* Copyright 2015 Akamai Technologies Inc. All Rights Reserved
5+
*
6+
* Authors:
7+
* Jason Baron <[email protected]>
8+
*
9+
* This software is licensed under the terms of the GNU General Public
10+
* License version 2, as published by the Free Software Foundation, and
11+
* may be copied, distributed, and modified under those terms.
12+
*
13+
* This program is distributed in the hope that it will be useful,
14+
* but WITHOUT ANY WARRANTY; without even the implied warranty of
15+
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16+
* GNU General Public License for more details.
17+
*/
18+
19+
#include <linux/module.h>
20+
#include <linux/jump_label.h>
21+
22+
/* old keys */
23+
struct static_key base_old_true_key = STATIC_KEY_INIT_TRUE;
24+
EXPORT_SYMBOL_GPL(base_old_true_key);
25+
struct static_key base_inv_old_true_key = STATIC_KEY_INIT_TRUE;
26+
EXPORT_SYMBOL_GPL(base_inv_old_true_key);
27+
struct static_key base_old_false_key = STATIC_KEY_INIT_FALSE;
28+
EXPORT_SYMBOL_GPL(base_old_false_key);
29+
struct static_key base_inv_old_false_key = STATIC_KEY_INIT_FALSE;
30+
EXPORT_SYMBOL_GPL(base_inv_old_false_key);
31+
32+
/* new keys */
33+
DEFINE_STATIC_KEY_TRUE(base_true_key);
34+
EXPORT_SYMBOL_GPL(base_true_key);
35+
DEFINE_STATIC_KEY_TRUE(base_inv_true_key);
36+
EXPORT_SYMBOL_GPL(base_inv_true_key);
37+
DEFINE_STATIC_KEY_FALSE(base_false_key);
38+
EXPORT_SYMBOL_GPL(base_false_key);
39+
DEFINE_STATIC_KEY_FALSE(base_inv_false_key);
40+
EXPORT_SYMBOL_GPL(base_inv_false_key);
41+
42+
static void invert_key(struct static_key *key)
43+
{
44+
if (static_key_enabled(key))
45+
static_key_disable(key);
46+
else
47+
static_key_enable(key);
48+
}
49+
50+
static int __init test_jump_label_base_init(void)
51+
{
52+
invert_key(&base_inv_old_true_key);
53+
invert_key(&base_inv_old_false_key);
54+
invert_key(&base_inv_true_key.key);
55+
invert_key(&base_inv_false_key.key);
56+
57+
return 0;
58+
}
59+
60+
static void __exit test_jump_label_base_exit(void)
61+
{
62+
}
63+
64+
module_init(test_jump_label_base_init);
65+
module_exit(test_jump_label_base_exit);
66+
67+
MODULE_AUTHOR("Jason Baron <[email protected]>");
68+
MODULE_LICENSE("GPL");

‎tools/testing/selftests/Makefile

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Original file line numberDiff line numberDiff line change
@@ -20,6 +20,7 @@ ifneq (1, $(quicktest))
2020
TARGETS += timers
2121
endif
2222
TARGETS += user
23+
TARGETS += jumplabel
2324
TARGETS += vm
2425
TARGETS += x86
2526
#Please keep the TARGETS list alphabetically sorted

‎tools/testing/selftests/jumplabel/Makefile

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1+
# Makefile for jump label selftests
2+
3+
# No binaries, but make sure arg-less "make" doesn't trigger "run_tests"
4+
all:
5+
6+
TEST_PROGS := test_jump_label.sh
7+
8+
include ../lib.mk

‎tools/testing/selftests/jumplabel/test_jump_label.sh

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1+
#!/bin/sh
2+
# Runs jump label kernel module tests
3+
4+
if /sbin/modprobe -q test_jump_label_base; then
5+
if /sbin/modprobe -q test_jump_label; then
6+
echo "jump_label: ok"
7+
/sbin/modprobe -q -r test_jump_label
8+
/sbin/modprobe -q -r test_jump_label_base
9+
else
10+
echo "jump_label: [FAIL]"
11+
/sbin/modprobe -q -r test_jump_label_base
12+
fi
13+
else
14+
echo "jump_label: [FAIL]"
15+
exit 1
16+
fi

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