diff options
| author | Ahmed S. Darwish <a.darwish@linutronix.de> | 2020-07-20 17:55:13 +0200 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2020-07-29 16:14:24 +0200 |
| commit | 8fd8ad5c5dfcb09cf62abadd4043eaf1afbbd0ce (patch) | |
| tree | d1959b43c4110967be60aa02352330d5a748fbda /include/linux/lockdep.h | |
| parent | 932e46365226324d2cf26d8bdec8b51ceb296948 (diff) | |
lockdep: Add preemption enabled/disabled assertion APIs
Asserting that preemption is enabled or disabled is a critical sanity
check. Developers are usually reluctant to add such a check in a
fastpath as reading the preemption count can be costly.
Extend the lockdep API with macros asserting that preemption is disabled
or enabled. If lockdep is disabled, or if the underlying architecture
does not support kernel preemption, this assert has no runtime overhead.
References: f54bb2ec02c8 ("locking/lockdep: Add IRQs disabled/enabled assertion APIs: ...")
Signed-off-by: Ahmed S. Darwish <a.darwish@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200720155530.1173732-8-a.darwish@linutronix.de
Diffstat (limited to 'include/linux/lockdep.h')
| -rw-r--r-- | include/linux/lockdep.h | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h index 7aafba0ddcf9..39a35699d0d6 100644 --- a/include/linux/lockdep.h +++ b/include/linux/lockdep.h @@ -549,6 +549,22 @@ do { \ WARN_ON_ONCE(debug_locks && !this_cpu_read(hardirq_context)); \ } while (0) +#define lockdep_assert_preemption_enabled() \ +do { \ + WARN_ON_ONCE(IS_ENABLED(CONFIG_PREEMPT_COUNT) && \ + debug_locks && \ + (preempt_count() != 0 || \ + !this_cpu_read(hardirqs_enabled))); \ +} while (0) + +#define lockdep_assert_preemption_disabled() \ +do { \ + WARN_ON_ONCE(IS_ENABLED(CONFIG_PREEMPT_COUNT) && \ + debug_locks && \ + (preempt_count() == 0 && \ + this_cpu_read(hardirqs_enabled))); \ +} while (0) + #else # define might_lock(lock) do { } while (0) # define might_lock_read(lock) do { } while (0) @@ -557,6 +573,9 @@ do { \ # define lockdep_assert_irqs_enabled() do { } while (0) # define lockdep_assert_irqs_disabled() do { } while (0) # define lockdep_assert_in_irq() do { } while (0) + +# define lockdep_assert_preemption_enabled() do { } while (0) +# define lockdep_assert_preemption_disabled() do { } while (0) #endif #ifdef CONFIG_PROVE_RAW_LOCK_NESTING |