From 2bf9e0ab08c64ac56067555911a1ae81ebff5f96 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Mon, 3 Aug 2015 11:42:57 +0200 Subject: locking/static_keys: Provide a selftest The 'jump label' self-test is in reality testing static keys - rename things accordingly. Also prettify the code in various places while at it. Acked-by: Peter Zijlstra (Intel) Cc: Andrew Morton Cc: Jason Baron Cc: Linus Torvalds Cc: Paul E. McKenney Cc: Peter Zijlstra Cc: Shuah Khan Cc: Thomas Gleixner 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: vbabka@suse.cz Cc: will.deacon@arm.com Link: http://lkml.kernel.org/r/0c091ecebd78a879ed8a71835d205a691a75ab4e.1438227999.git.jbaron@akamai.com Signed-off-by: Ingo Molnar --- lib/test_static_keys.c | 225 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 225 insertions(+) create mode 100644 lib/test_static_keys.c (limited to 'lib/test_static_keys.c') diff --git a/lib/test_static_keys.c b/lib/test_static_keys.c new file mode 100644 index 000000000000..81d81052eb8d --- /dev/null +++ b/lib/test_static_keys.c @@ -0,0 +1,225 @@ +/* + * Kernel module for testing static keys. + * + * Copyright 2015 Akamai Technologies Inc. All Rights Reserved + * + * Authors: + * Jason Baron + * + * 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 +#include + +/* 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_key { + 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_key *keys, int size) +{ + struct static_key *previous = NULL; + int i; + + for (i = 0; i < size; i++) { + if (previous != keys[i].key) { + invert_key(keys[i].key); + previous = keys[i].key; + } + } +} + +int verify_keys(struct test_key *keys, int size, bool invert) +{ + int i; + bool ret, init; + + for (i = 0; i < size; i++) { + ret = static_key_enabled(keys[i].key); + init = keys[i].init_state; + if (ret != (invert ? !init : init)) + return -EINVAL; + ret = keys[i].test_key(); + if (static_key_enabled(keys[i].key)) { + if (!ret) + return -EINVAL; + } else { + if (ret) + return -EINVAL; + } + } + return 0; +} + +static int __init test_static_key_init(void) +{ + int ret; + int size; + + struct test_key static_key_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(static_key_tests); + + ret = verify_keys(static_key_tests, size, false); + if (ret) + goto out; + + invert_keys(static_key_tests, size); + ret = verify_keys(static_key_tests, size, true); + if (ret) + goto out; + + invert_keys(static_key_tests, size); + ret = verify_keys(static_key_tests, size, false); + if (ret) + goto out; + return 0; +out: + return ret; +} + +static void __exit test_static_key_exit(void) +{ +} + +module_init(test_static_key_init); +module_exit(test_static_key_exit); + +MODULE_AUTHOR("Jason Baron "); +MODULE_LICENSE("GPL"); -- cgit v1.2.3