From 9271a40d2a1429113160ccc4c16150921600bcc1 Mon Sep 17 00:00:00 2001 From: Boqun Feng Date: Tue, 8 Dec 2020 18:31:12 +0800 Subject: [PATCH] lockdep/selftest: Add wait context selftests These tests are added for two purposes: * Test the implementation of wait context checks and related annotations. * Semi-document the rules for wait context nesting when PROVE_RAW_LOCK_NESTING=y. The test cases are only avaible for PROVE_RAW_LOCK_NESTING=y, as wait context checking makes more sense for that configuration. Signed-off-by: Boqun Feng Signed-off-by: Peter Zijlstra (Intel) Link: https://lkml.kernel.org/r/20201208103112.2838119-5-boqun.feng@gmail.com --- lib/locking-selftest.c | 232 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 232 insertions(+) diff --git a/lib/locking-selftest.c b/lib/locking-selftest.c index 9959ea23529e..23376eeccf7c 100644 --- a/lib/locking-selftest.c +++ b/lib/locking-selftest.c @@ -64,6 +64,9 @@ static DEFINE_SPINLOCK(lock_B); static DEFINE_SPINLOCK(lock_C); static DEFINE_SPINLOCK(lock_D); +static DEFINE_RAW_SPINLOCK(raw_lock_A); +static DEFINE_RAW_SPINLOCK(raw_lock_B); + static DEFINE_RWLOCK(rwlock_A); static DEFINE_RWLOCK(rwlock_B); static DEFINE_RWLOCK(rwlock_C); @@ -1306,6 +1309,7 @@ GENERATE_PERMUTATIONS_3_EVENTS(irq_read_recursion3_soft_wlock) #ifdef CONFIG_DEBUG_LOCK_ALLOC # define I_SPINLOCK(x) lockdep_reset_lock(&lock_##x.dep_map) +# define I_RAW_SPINLOCK(x) lockdep_reset_lock(&raw_lock_##x.dep_map) # define I_RWLOCK(x) lockdep_reset_lock(&rwlock_##x.dep_map) # define I_MUTEX(x) lockdep_reset_lock(&mutex_##x.dep_map) # define I_RWSEM(x) lockdep_reset_lock(&rwsem_##x.dep_map) @@ -1315,6 +1319,7 @@ GENERATE_PERMUTATIONS_3_EVENTS(irq_read_recursion3_soft_wlock) #endif #else # define I_SPINLOCK(x) +# define I_RAW_SPINLOCK(x) # define I_RWLOCK(x) # define I_MUTEX(x) # define I_RWSEM(x) @@ -1358,9 +1363,12 @@ static void reset_locks(void) I1(A); I1(B); I1(C); I1(D); I1(X1); I1(X2); I1(Y1); I1(Y2); I1(Z1); I1(Z2); I_WW(t); I_WW(t2); I_WW(o.base); I_WW(o2.base); I_WW(o3.base); + I_RAW_SPINLOCK(A); I_RAW_SPINLOCK(B); lockdep_reset(); I2(A); I2(B); I2(C); I2(D); init_shared_classes(); + raw_spin_lock_init(&raw_lock_A); + raw_spin_lock_init(&raw_lock_B); ww_mutex_init(&o, &ww_lockdep); ww_mutex_init(&o2, &ww_lockdep); ww_mutex_init(&o3, &ww_lockdep); memset(&t, 0, sizeof(t)); memset(&t2, 0, sizeof(t2)); @@ -2419,6 +2427,226 @@ static void fs_reclaim_tests(void) pr_cont("\n"); } +#define __guard(cleanup) __maybe_unused __attribute__((__cleanup__(cleanup))) + +static void hardirq_exit(int *_) +{ + HARDIRQ_EXIT(); +} + +#define HARDIRQ_CONTEXT(name, ...) \ + int hardirq_guard_##name __guard(hardirq_exit); \ + HARDIRQ_ENTER(); + +#define NOTTHREADED_HARDIRQ_CONTEXT(name, ...) \ + int notthreaded_hardirq_guard_##name __guard(hardirq_exit); \ + local_irq_disable(); \ + __irq_enter(); \ + WARN_ON(!in_irq()); + +static void softirq_exit(int *_) +{ + SOFTIRQ_EXIT(); +} + +#define SOFTIRQ_CONTEXT(name, ...) \ + int softirq_guard_##name __guard(softirq_exit); \ + SOFTIRQ_ENTER(); + +static void rcu_exit(int *_) +{ + rcu_read_unlock(); +} + +#define RCU_CONTEXT(name, ...) \ + int rcu_guard_##name __guard(rcu_exit); \ + rcu_read_lock(); + +static void rcu_bh_exit(int *_) +{ + rcu_read_unlock_bh(); +} + +#define RCU_BH_CONTEXT(name, ...) \ + int rcu_bh_guard_##name __guard(rcu_bh_exit); \ + rcu_read_lock_bh(); + +static void rcu_sched_exit(int *_) +{ + rcu_read_unlock_sched(); +} + +#define RCU_SCHED_CONTEXT(name, ...) \ + 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); +} + +#define RAW_SPINLOCK_CONTEXT(name, lock) \ + raw_spinlock_t *raw_spinlock_guard_##name __guard(raw_spinlock_exit) = &(lock); \ + raw_spin_lock(&(lock)); + +static void spinlock_exit(spinlock_t **lock) +{ + spin_unlock(*lock); +} + +#define SPINLOCK_CONTEXT(name, lock) \ + spinlock_t *spinlock_guard_##name __guard(spinlock_exit) = &(lock); \ + spin_lock(&(lock)); + +static void mutex_exit(struct mutex **lock) +{ + mutex_unlock(*lock); +} + +#define MUTEX_CONTEXT(name, lock) \ + struct mutex *mutex_guard_##name __guard(mutex_exit) = &(lock); \ + mutex_lock(&(lock)); + +#define GENERATE_2_CONTEXT_TESTCASE(outer, outer_lock, inner, inner_lock) \ + \ +static void __maybe_unused inner##_in_##outer(void) \ +{ \ + outer##_CONTEXT(_, outer_lock); \ + { \ + inner##_CONTEXT(_, inner_lock); \ + } \ +} + +/* + * wait contexts (considering PREEMPT_RT) + * + * o: inner is allowed in outer + * x: inner is disallowed in outer + * + * \ inner | RCU | RAW_SPIN | SPIN | MUTEX + * outer \ | | | | + * ---------------+-------+----------+------+------- + * HARDIRQ | o | o | o | x + * ---------------+-------+----------+------+------- + * NOTTHREADED_IRQ| o | o | x | x + * ---------------+-------+----------+------+------- + * SOFTIRQ | o | o | o | x + * ---------------+-------+----------+------+------- + * RCU | o | o | o | x + * ---------------+-------+----------+------+------- + * RCU_BH | o | o | o | x + * ---------------+-------+----------+------+------- + * RCU_CALLBACK | o | o | o | x + * ---------------+-------+----------+------+------- + * RCU_SCHED | o | o | x | x + * ---------------+-------+----------+------+------- + * RAW_SPIN | o | o | x | x + * ---------------+-------+----------+------+------- + * SPIN | o | o | o | x + * ---------------+-------+----------+------+------- + * MUTEX | o | o | o | o + * ---------------+-------+----------+------+------- + */ + +#define GENERATE_2_CONTEXT_TESTCASE_FOR_ALL_OUTER(inner, inner_lock) \ +GENERATE_2_CONTEXT_TESTCASE(HARDIRQ, , inner, inner_lock) \ +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) \ +GENERATE_2_CONTEXT_TESTCASE(MUTEX, mutex_A, inner, inner_lock) + +GENERATE_2_CONTEXT_TESTCASE_FOR_ALL_OUTER(RCU, ) +GENERATE_2_CONTEXT_TESTCASE_FOR_ALL_OUTER(RAW_SPINLOCK, raw_lock_B) +GENERATE_2_CONTEXT_TESTCASE_FOR_ALL_OUTER(SPINLOCK, lock_B) +GENERATE_2_CONTEXT_TESTCASE_FOR_ALL_OUTER(MUTEX, mutex_B) + +/* the outer context allows all kinds of preemption */ +#define DO_CONTEXT_TESTCASE_OUTER_PREEMPTIBLE(outer) \ + dotest(RCU_in_##outer, SUCCESS, LOCKTYPE_RWLOCK); \ + dotest(RAW_SPINLOCK_in_##outer, SUCCESS, LOCKTYPE_SPIN); \ + dotest(SPINLOCK_in_##outer, SUCCESS, LOCKTYPE_SPIN); \ + dotest(MUTEX_in_##outer, SUCCESS, LOCKTYPE_MUTEX); \ + +/* + * the outer context only allows the preemption introduced by spinlock_t (which + * is a sleepable lock for PREEMPT_RT) + */ +#define DO_CONTEXT_TESTCASE_OUTER_LIMITED_PREEMPTIBLE(outer) \ + dotest(RCU_in_##outer, SUCCESS, LOCKTYPE_RWLOCK); \ + dotest(RAW_SPINLOCK_in_##outer, SUCCESS, LOCKTYPE_SPIN); \ + dotest(SPINLOCK_in_##outer, SUCCESS, LOCKTYPE_SPIN); \ + dotest(MUTEX_in_##outer, FAILURE, LOCKTYPE_MUTEX); \ + +/* the outer doesn't allows any kind of preemption */ +#define DO_CONTEXT_TESTCASE_OUTER_NOT_PREEMPTIBLE(outer) \ + dotest(RCU_in_##outer, SUCCESS, LOCKTYPE_RWLOCK); \ + dotest(RAW_SPINLOCK_in_##outer, SUCCESS, LOCKTYPE_SPIN); \ + dotest(SPINLOCK_in_##outer, FAILURE, LOCKTYPE_SPIN); \ + dotest(MUTEX_in_##outer, FAILURE, LOCKTYPE_MUTEX); \ + +static void wait_context_tests(void) +{ + printk(" --------------------------------------------------------------------------\n"); + printk(" | wait context tests |\n"); + printk(" --------------------------------------------------------------------------\n"); + printk(" | rcu | raw | spin |mutex |\n"); + printk(" --------------------------------------------------------------------------\n"); + print_testname("in hardirq context"); + DO_CONTEXT_TESTCASE_OUTER_LIMITED_PREEMPTIBLE(HARDIRQ); + pr_cont("\n"); + + print_testname("in hardirq context (not threaded)"); + DO_CONTEXT_TESTCASE_OUTER_NOT_PREEMPTIBLE(NOTTHREADED_HARDIRQ); + pr_cont("\n"); + + print_testname("in softirq context"); + DO_CONTEXT_TESTCASE_OUTER_LIMITED_PREEMPTIBLE(SOFTIRQ); + pr_cont("\n"); + + print_testname("in RCU context"); + DO_CONTEXT_TESTCASE_OUTER_LIMITED_PREEMPTIBLE(RCU); + pr_cont("\n"); + + print_testname("in RCU-bh context"); + 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"); + + print_testname("in RAW_SPINLOCK context"); + DO_CONTEXT_TESTCASE_OUTER_NOT_PREEMPTIBLE(RAW_SPINLOCK); + pr_cont("\n"); + + print_testname("in SPINLOCK context"); + DO_CONTEXT_TESTCASE_OUTER_LIMITED_PREEMPTIBLE(SPINLOCK); + pr_cont("\n"); + + print_testname("in MUTEX context"); + DO_CONTEXT_TESTCASE_OUTER_PREEMPTIBLE(MUTEX); + pr_cont("\n"); +} + void locking_selftest(void) { /* @@ -2542,6 +2770,10 @@ void locking_selftest(void) fs_reclaim_tests(); + /* Wait context test cases that are specific for RAW_LOCK_NESTING */ + if (IS_ENABLED(CONFIG_PROVE_RAW_LOCK_NESTING)) + wait_context_tests(); + if (unexpected_testcase_failures) { printk("-----------------------------------------------------------------\n"); debug_locks = 0;