/* * 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) \ static bool key ## _ ## branch(void) \ { \ return branch(&key); \ } 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; } } } static 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; } test_key_func(old_true_key, static_key_true) test_key_func(old_false_key, static_key_false) test_key_func(true_key, static_branch_likely) test_key_func(true_key, static_branch_unlikely) test_key_func(false_key, static_branch_likely) test_key_func(false_key, static_branch_unlikely) test_key_func(base_old_true_key, static_key_true) test_key_func(base_inv_old_true_key, static_key_true) test_key_func(base_old_false_key, static_key_false) test_key_func(base_inv_old_false_key, static_key_false) test_key_func(base_true_key, static_branch_likely) test_key_func(base_true_key, static_branch_unlikely) test_key_func(base_inv_true_key, static_branch_likely) test_key_func(base_inv_true_key, static_branch_unlikely) test_key_func(base_false_key, static_branch_likely) test_key_func(base_false_key, static_branch_unlikely) test_key_func(base_inv_false_key, static_branch_likely) test_key_func(base_inv_false_key, static_branch_unlikely) 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 = &old_true_key_static_key_true, }, { .init_state = false, .key = &old_false_key, .test_key = &old_false_key_static_key_false, }, /* internal keys - new keys */ { .init_state = true, .key = &true_key.key, .test_key = &true_key_static_branch_likely, }, { .init_state = true, .key = &true_key.key, .test_key = &true_key_static_branch_unlikely, }, { .init_state = false, .key = &false_key.key, .test_key = &false_key_static_branch_likely, }, { .init_state = false, .key = &false_key.key, .test_key = &false_key_static_branch_unlikely, }, /* external keys - old keys */ { .init_state = true, .key = &base_old_true_key, .test_key = &base_old_true_key_static_key_true, }, { .init_state = false, .key = &base_inv_old_true_key, .test_key = &base_inv_old_true_key_static_key_true, }, { .init_state = false, .key = &base_old_false_key, .test_key = &base_old_false_key_static_key_false, }, { .init_state = true, .key = &base_inv_old_false_key, .test_key = &base_inv_old_false_key_static_key_false, }, /* external keys - new keys */ { .init_state = true, .key = &base_true_key.key, .test_key = &base_true_key_static_branch_likely, }, { .init_state = true, .key = &base_true_key.key, .test_key = &base_true_key_static_branch_unlikely, }, { .init_state = false, .key = &base_inv_true_key.key, .test_key = &base_inv_true_key_static_branch_likely, }, { .init_state = false, .key = &base_inv_true_key.key, .test_key = &base_inv_true_key_static_branch_unlikely, }, { .init_state = false, .key = &base_false_key.key, .test_key = &base_false_key_static_branch_likely, }, { .init_state = false, .key = &base_false_key.key, .test_key = &base_false_key_static_branch_unlikely, }, { .init_state = true, .key = &base_inv_false_key.key, .test_key = &base_inv_false_key_static_branch_likely, }, { .init_state = true, .key = &base_inv_false_key.key, .test_key = &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"); ot change after that happens. The original code created the thread at the first instance it was called, but later was changed to destroy the thread after the tracer was finished, and would not be created until the next instance of the tracer was established. The code that initialized the affinity was only called on the initial instantiation of the tracer. After that, it was not initialized, and the previous affinity did not match the current newly created one, making it appear that the user modified the thread's affinity when it did not, and the thread failed to migrate again. Cc: stable@vger.kernel.org Fixes: 0330f7aa8ee6 ("tracing: Have hwlat trace migrate across tracing_cpumask CPUs") Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Diffstat (limited to 'include/trace/events')