diff options
Diffstat (limited to 'lib/test_jump_label.c')
| -rw-r--r-- | lib/test_jump_label.c | 225 |
1 files changed, 225 insertions, 0 deletions
diff --git a/lib/test_jump_label.c b/lib/test_jump_label.c new file mode 100644 index 000000000000..2fe741329b0e --- /dev/null +++ b/lib/test_jump_label.c @@ -0,0 +1,225 @@ +/* + * 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"); |