From 7e923e6a3ceb877497dd9ee70d71fa33b94f332b Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Wed, 9 Dec 2020 16:06:06 +0100 Subject: [PATCH] locking/selftests: Add local_lock inversion tests Test the local_lock_t inversion scenarios. Signed-off-by: Peter Zijlstra (Intel) --- lib/locking-selftest.c | 97 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 97 insertions(+) diff --git a/lib/locking-selftest.c b/lib/locking-selftest.c index 3306f43b0007..2d85abac1744 100644 --- a/lib/locking-selftest.c +++ b/lib/locking-selftest.c @@ -24,6 +24,7 @@ #include #include #include +#include /* * Change this to 1 if you want to see the failure printouts: @@ -51,6 +52,7 @@ __setup("debug_locks_verbose=", setup_debug_locks_verbose); #define LOCKTYPE_RWSEM 0x8 #define LOCKTYPE_WW 0x10 #define LOCKTYPE_RTMUTEX 0x20 +#define LOCKTYPE_LL 0x40 static struct ww_acquire_ctx t, t2; static struct ww_mutex o, o2, o3; @@ -136,6 +138,8 @@ static DEFINE_RT_MUTEX(rtmutex_Z2); #endif +static local_lock_t local_A = INIT_LOCAL_LOCK(local_A); + /* * non-inlined runtime initializers, to let separate locks share * the same lock-class: @@ -1314,6 +1318,7 @@ GENERATE_PERMUTATIONS_3_EVENTS(irq_read_recursion3_soft_wlock) # define I_MUTEX(x) lockdep_reset_lock(&mutex_##x.dep_map) # define I_RWSEM(x) lockdep_reset_lock(&rwsem_##x.dep_map) # define I_WW(x) lockdep_reset_lock(&x.dep_map) +# define I_LOCAL_LOCK(x) lockdep_reset_lock(&local_##x.dep_map) #ifdef CONFIG_RT_MUTEXES # define I_RTMUTEX(x) lockdep_reset_lock(&rtmutex_##x.dep_map) #endif @@ -1324,6 +1329,7 @@ GENERATE_PERMUTATIONS_3_EVENTS(irq_read_recursion3_soft_wlock) # define I_MUTEX(x) # define I_RWSEM(x) # define I_WW(x) +# define I_LOCAL_LOCK(x) #endif #ifndef I_RTMUTEX @@ -1364,11 +1370,15 @@ static void reset_locks(void) 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); + I_LOCAL_LOCK(A); + 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); + local_lock_init(&local_A); 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)); @@ -2649,6 +2659,91 @@ static void wait_context_tests(void) pr_cont("\n"); } +static void local_lock_2(void) +{ + local_lock_acquire(&local_A); /* IRQ-ON */ + local_lock_release(&local_A); + + HARDIRQ_ENTER(); + spin_lock(&lock_A); /* IN-IRQ */ + spin_unlock(&lock_A); + HARDIRQ_EXIT() + + HARDIRQ_DISABLE(); + spin_lock(&lock_A); + local_lock_acquire(&local_A); /* IN-IRQ <-> IRQ-ON cycle, false */ + local_lock_release(&local_A); + spin_unlock(&lock_A); + HARDIRQ_ENABLE(); +} + +static void local_lock_3A(void) +{ + local_lock_acquire(&local_A); /* IRQ-ON */ + spin_lock(&lock_B); /* IRQ-ON */ + spin_unlock(&lock_B); + local_lock_release(&local_A); + + HARDIRQ_ENTER(); + spin_lock(&lock_A); /* IN-IRQ */ + spin_unlock(&lock_A); + HARDIRQ_EXIT() + + HARDIRQ_DISABLE(); + spin_lock(&lock_A); + local_lock_acquire(&local_A); /* IN-IRQ <-> IRQ-ON cycle only if we count local_lock(), false */ + local_lock_release(&local_A); + spin_unlock(&lock_A); + HARDIRQ_ENABLE(); +} + +static void local_lock_3B(void) +{ + local_lock_acquire(&local_A); /* IRQ-ON */ + spin_lock(&lock_B); /* IRQ-ON */ + spin_unlock(&lock_B); + local_lock_release(&local_A); + + HARDIRQ_ENTER(); + spin_lock(&lock_A); /* IN-IRQ */ + spin_unlock(&lock_A); + HARDIRQ_EXIT() + + HARDIRQ_DISABLE(); + spin_lock(&lock_A); + local_lock_acquire(&local_A); /* IN-IRQ <-> IRQ-ON cycle only if we count local_lock(), false */ + local_lock_release(&local_A); + spin_unlock(&lock_A); + HARDIRQ_ENABLE(); + + HARDIRQ_DISABLE(); + spin_lock(&lock_A); + spin_lock(&lock_B); /* IN-IRQ <-> IRQ-ON cycle, true */ + spin_unlock(&lock_B); + spin_unlock(&lock_A); + HARDIRQ_DISABLE(); + +} + +static void local_lock_tests(void) +{ + printk(" --------------------------------------------------------------------------\n"); + printk(" | local_lock tests |\n"); + printk(" ---------------------\n"); + + print_testname("local_lock inversion 2"); + dotest(local_lock_2, SUCCESS, LOCKTYPE_LL); + pr_cont("\n"); + + print_testname("local_lock inversion 3A"); + dotest(local_lock_3A, SUCCESS, LOCKTYPE_LL); + pr_cont("\n"); + + print_testname("local_lock inversion 3B"); + dotest(local_lock_3B, FAILURE, LOCKTYPE_LL); + pr_cont("\n"); +} + void locking_selftest(void) { /* @@ -2775,6 +2870,8 @@ void locking_selftest(void) if (IS_ENABLED(CONFIG_PROVE_RAW_LOCK_NESTING)) wait_context_tests(); + local_lock_tests(); + if (unexpected_testcase_failures) { printk("-----------------------------------------------------------------\n"); debug_locks = 0;