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| author | Peter Zijlstra <peterz@infradead.org> | 2015-07-27 18:32:09 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2015-08-03 11:34:16 +0200 |
| commit | 1987c947d905baa05bee430178e8eef882f36bd4 (patch) | |
| tree | 3e1bf8a1224c9c929b5546b5be98569d508c80e4 | |
| parent | 11276d5306b8e5b438a36bbff855fe792d7eaa61 (diff) | |
| download | lwn-1987c947d905baa05bee430178e8eef882f36bd4.tar.gz lwn-1987c947d905baa05bee430178e8eef882f36bd4.zip | |
locking/static_keys: Add selftest
Add a little selftest that validates all combinations.
Signed-off-by: Peter 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: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
| -rw-r--r-- | arch/Kconfig | 6 | ||||
| -rw-r--r-- | kernel/jump_label.c | 39 |
2 files changed, 44 insertions, 1 deletions
diff --git a/arch/Kconfig b/arch/Kconfig index 8a8ea7110de8..a71cdbe2a04d 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -71,6 +71,12 @@ config JUMP_LABEL ( On 32-bit x86, the necessary options added to the compiler flags may increase the size of the kernel slightly. ) +config STATIC_KEYS_SELFTEST + bool "Static key selftest" + depends on JUMP_LABEL + help + Boot time self-test of the branch patching code. + config OPTPROBES def_bool y depends on KPROBES && HAVE_OPTPROBES diff --git a/kernel/jump_label.c b/kernel/jump_label.c index 8fd00d892286..f7dd15d537f9 100644 --- a/kernel/jump_label.c +++ b/kernel/jump_label.c @@ -482,4 +482,41 @@ static void jump_label_update(struct static_key *key) __jump_label_update(key, entry, stop); } -#endif +#ifdef CONFIG_STATIC_KEYS_SELFTEST +static DEFINE_STATIC_KEY_TRUE(sk_true); +static DEFINE_STATIC_KEY_FALSE(sk_false); + +static __init int jump_label_test(void) +{ + int i; + + for (i = 0; i < 2; i++) { + WARN_ON(static_key_enabled(&sk_true.key) != true); + WARN_ON(static_key_enabled(&sk_false.key) != false); + + WARN_ON(!static_branch_likely(&sk_true)); + WARN_ON(!static_branch_unlikely(&sk_true)); + WARN_ON(static_branch_likely(&sk_false)); + WARN_ON(static_branch_unlikely(&sk_false)); + + static_branch_disable(&sk_true); + static_branch_enable(&sk_false); + + WARN_ON(static_key_enabled(&sk_true.key) == true); + WARN_ON(static_key_enabled(&sk_false.key) == false); + + WARN_ON(static_branch_likely(&sk_true)); + WARN_ON(static_branch_unlikely(&sk_true)); + WARN_ON(!static_branch_likely(&sk_false)); + WARN_ON(!static_branch_unlikely(&sk_false)); + + static_branch_enable(&sk_true); + static_branch_disable(&sk_false); + } + + return 0; +} +late_initcall(jump_label_test); +#endif /* STATIC_KEYS_SELFTEST */ + +#endif /* HAVE_JUMP_LABEL */ |