diff options
Diffstat (limited to 'lib/locking-selftest.c')
| -rw-r--r-- | lib/locking-selftest.c | 83 |
1 files changed, 66 insertions, 17 deletions
diff --git a/lib/locking-selftest.c b/lib/locking-selftest.c index 2d85abac1744..161108e5d2fe 100644 --- a/lib/locking-selftest.c +++ b/lib/locking-selftest.c @@ -53,6 +53,7 @@ __setup("debug_locks_verbose=", setup_debug_locks_verbose); #define LOCKTYPE_WW 0x10 #define LOCKTYPE_RTMUTEX 0x20 #define LOCKTYPE_LL 0x40 +#define LOCKTYPE_SPECIAL 0x80 static struct ww_acquire_ctx t, t2; static struct ww_mutex o, o2, o3; @@ -194,6 +195,7 @@ static void init_shared_classes(void) #define HARDIRQ_ENTER() \ local_irq_disable(); \ __irq_enter(); \ + lockdep_hardirq_threaded(); \ WARN_ON(!in_irq()); #define HARDIRQ_EXIT() \ @@ -2492,16 +2494,6 @@ static void rcu_sched_exit(int *_) int rcu_sched_guard_##name __guard(rcu_sched_exit); \ rcu_read_lock_sched(); -static void rcu_callback_exit(int *_) -{ - rcu_lock_release(&rcu_callback_map); -} - -#define RCU_CALLBACK_CONTEXT(name, ...) \ - int rcu_callback_guard_##name __guard(rcu_callback_exit); \ - rcu_lock_acquire(&rcu_callback_map); - - static void raw_spinlock_exit(raw_spinlock_t **lock) { raw_spin_unlock(*lock); @@ -2558,8 +2550,6 @@ static void __maybe_unused inner##_in_##outer(void) \ * ---------------+-------+----------+------+------- * RCU_BH | o | o | o | x * ---------------+-------+----------+------+------- - * RCU_CALLBACK | o | o | o | x - * ---------------+-------+----------+------+------- * RCU_SCHED | o | o | x | x * ---------------+-------+----------+------+------- * RAW_SPIN | o | o | x | x @@ -2576,7 +2566,6 @@ GENERATE_2_CONTEXT_TESTCASE(NOTTHREADED_HARDIRQ, , inner, inner_lock) \ GENERATE_2_CONTEXT_TESTCASE(SOFTIRQ, , inner, inner_lock) \ GENERATE_2_CONTEXT_TESTCASE(RCU, , inner, inner_lock) \ GENERATE_2_CONTEXT_TESTCASE(RCU_BH, , inner, inner_lock) \ -GENERATE_2_CONTEXT_TESTCASE(RCU_CALLBACK, , inner, inner_lock) \ GENERATE_2_CONTEXT_TESTCASE(RCU_SCHED, , inner, inner_lock) \ GENERATE_2_CONTEXT_TESTCASE(RAW_SPINLOCK, raw_lock_A, inner, inner_lock) \ GENERATE_2_CONTEXT_TESTCASE(SPINLOCK, lock_A, inner, inner_lock) \ @@ -2638,10 +2627,6 @@ static void wait_context_tests(void) DO_CONTEXT_TESTCASE_OUTER_LIMITED_PREEMPTIBLE(RCU_BH); pr_cont("\n"); - print_testname("in RCU callback context"); - DO_CONTEXT_TESTCASE_OUTER_LIMITED_PREEMPTIBLE(RCU_CALLBACK); - pr_cont("\n"); - print_testname("in RCU-sched context"); DO_CONTEXT_TESTCASE_OUTER_NOT_PREEMPTIBLE(RCU_SCHED); pr_cont("\n"); @@ -2744,6 +2729,66 @@ static void local_lock_tests(void) pr_cont("\n"); } +static void hardirq_deadlock_softirq_not_deadlock(void) +{ + /* mutex_A is hardirq-unsafe and softirq-unsafe */ + /* mutex_A -> lock_C */ + mutex_lock(&mutex_A); + HARDIRQ_DISABLE(); + spin_lock(&lock_C); + spin_unlock(&lock_C); + HARDIRQ_ENABLE(); + mutex_unlock(&mutex_A); + + /* lock_A is hardirq-safe */ + HARDIRQ_ENTER(); + spin_lock(&lock_A); + spin_unlock(&lock_A); + HARDIRQ_EXIT(); + + /* lock_A -> lock_B */ + HARDIRQ_DISABLE(); + spin_lock(&lock_A); + spin_lock(&lock_B); + spin_unlock(&lock_B); + spin_unlock(&lock_A); + HARDIRQ_ENABLE(); + + /* lock_B -> lock_C */ + HARDIRQ_DISABLE(); + spin_lock(&lock_B); + spin_lock(&lock_C); + spin_unlock(&lock_C); + spin_unlock(&lock_B); + HARDIRQ_ENABLE(); + + /* lock_D is softirq-safe */ + SOFTIRQ_ENTER(); + spin_lock(&lock_D); + spin_unlock(&lock_D); + SOFTIRQ_EXIT(); + + /* And lock_D is hardirq-unsafe */ + SOFTIRQ_DISABLE(); + spin_lock(&lock_D); + spin_unlock(&lock_D); + SOFTIRQ_ENABLE(); + + /* + * mutex_A -> lock_C -> lock_D is softirq-unsafe -> softirq-safe, not + * deadlock. + * + * lock_A -> lock_B -> lock_C -> lock_D is hardirq-safe -> + * hardirq-unsafe, deadlock. + */ + HARDIRQ_DISABLE(); + spin_lock(&lock_C); + spin_lock(&lock_D); + spin_unlock(&lock_D); + spin_unlock(&lock_C); + HARDIRQ_ENABLE(); +} + void locking_selftest(void) { /* @@ -2872,6 +2917,10 @@ void locking_selftest(void) local_lock_tests(); + print_testname("hardirq_unsafe_softirq_safe"); + dotest(hardirq_deadlock_softirq_not_deadlock, FAILURE, LOCKTYPE_SPECIAL); + pr_cont("\n"); + if (unexpected_testcase_failures) { printk("-----------------------------------------------------------------\n"); debug_locks = 0; |