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linux/lib/locking-selftest.c
Frederic Weisbecker ba9f207c9f rcu: Fix unpaired rcu_irq_enter() from locking selftests 
HARDIRQ_ENTER() maps to irq_enter() which calls rcu_irq_enter().
But HARDIRQ_EXIT() maps to __irq_exit() which doesn't call
rcu_irq_exit().

So for every locking selftest that simulates hardirq disabled,
we create an imbalance in the rcu extended quiescent state
internal state.

As a result, after the first missing rcu_irq_exit(), subsequent
irqs won't exit dyntick-idle mode after leaving the interrupt
handler.  This means that RCU won't see the affected CPU as being
in an extended quiescent state, resulting in long grace-period
delays (as in grace periods extending for hours).

To fix this, just use __irq_enter() to simulate the hardirq
context. This is sufficient for the locking selftests as we
don't need to exit any extended quiescent state or perform
any check that irqs normally do when they wake up from idle.

As a side effect, this patch makes it possible to restore
"rcu: Decrease memory-barrier usage based on semi-formal proof",
which eventually helped finding this bug.

Reported-and-tested-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stable <stable@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2011-05-26 09:42:19 -07:00

1219 lines
29 KiB
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/*
* lib/locking-selftest.c
*
* Testsuite for various locking APIs: spinlocks, rwlocks,
* mutexes and rw-semaphores.
*
* It is checking both false positives and false negatives.
*
* Started by Ingo Molnar:
*
* Copyright (C) 2006 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
*/
#include <linux/rwsem.h>
#include <linux/mutex.h>
#include <linux/sched.h>
#include <linux/delay.h>
#include <linux/module.h>
#include <linux/lockdep.h>
#include <linux/spinlock.h>
#include <linux/kallsyms.h>
#include <linux/interrupt.h>
#include <linux/debug_locks.h>
#include <linux/irqflags.h>
/*
* Change this to 1 if you want to see the failure printouts:
*/
static unsigned int debug_locks_verbose;
static int __init setup_debug_locks_verbose(char *str)
{
get_option(&str, &debug_locks_verbose);
return 1;
}
__setup("debug_locks_verbose=", setup_debug_locks_verbose);
#define FAILURE 0
#define SUCCESS 1
#define LOCKTYPE_SPIN 0x1
#define LOCKTYPE_RWLOCK 0x2
#define LOCKTYPE_MUTEX 0x4
#define LOCKTYPE_RWSEM 0x8
/*
* Normal standalone locks, for the circular and irq-context
* dependency tests:
*/
static DEFINE_SPINLOCK(lock_A);
static DEFINE_SPINLOCK(lock_B);
static DEFINE_SPINLOCK(lock_C);
static DEFINE_SPINLOCK(lock_D);
static DEFINE_RWLOCK(rwlock_A);
static DEFINE_RWLOCK(rwlock_B);
static DEFINE_RWLOCK(rwlock_C);
static DEFINE_RWLOCK(rwlock_D);
static DEFINE_MUTEX(mutex_A);
static DEFINE_MUTEX(mutex_B);
static DEFINE_MUTEX(mutex_C);
static DEFINE_MUTEX(mutex_D);
static DECLARE_RWSEM(rwsem_A);
static DECLARE_RWSEM(rwsem_B);
static DECLARE_RWSEM(rwsem_C);
static DECLARE_RWSEM(rwsem_D);
/*
* Locks that we initialize dynamically as well so that
* e.g. X1 and X2 becomes two instances of the same class,
* but X* and Y* are different classes. We do this so that
* we do not trigger a real lockup:
*/
static DEFINE_SPINLOCK(lock_X1);
static DEFINE_SPINLOCK(lock_X2);
static DEFINE_SPINLOCK(lock_Y1);
static DEFINE_SPINLOCK(lock_Y2);
static DEFINE_SPINLOCK(lock_Z1);
static DEFINE_SPINLOCK(lock_Z2);
static DEFINE_RWLOCK(rwlock_X1);
static DEFINE_RWLOCK(rwlock_X2);
static DEFINE_RWLOCK(rwlock_Y1);
static DEFINE_RWLOCK(rwlock_Y2);
static DEFINE_RWLOCK(rwlock_Z1);
static DEFINE_RWLOCK(rwlock_Z2);
static DEFINE_MUTEX(mutex_X1);
static DEFINE_MUTEX(mutex_X2);
static DEFINE_MUTEX(mutex_Y1);
static DEFINE_MUTEX(mutex_Y2);
static DEFINE_MUTEX(mutex_Z1);
static DEFINE_MUTEX(mutex_Z2);
static DECLARE_RWSEM(rwsem_X1);
static DECLARE_RWSEM(rwsem_X2);
static DECLARE_RWSEM(rwsem_Y1);
static DECLARE_RWSEM(rwsem_Y2);
static DECLARE_RWSEM(rwsem_Z1);
static DECLARE_RWSEM(rwsem_Z2);
/*
* non-inlined runtime initializers, to let separate locks share
* the same lock-class:
*/
#define INIT_CLASS_FUNC(class) \
static noinline void \
init_class_##class(spinlock_t *lock, rwlock_t *rwlock, struct mutex *mutex, \
struct rw_semaphore *rwsem) \
{ \
spin_lock_init(lock); \
rwlock_init(rwlock); \
mutex_init(mutex); \
init_rwsem(rwsem); \
}
INIT_CLASS_FUNC(X)
INIT_CLASS_FUNC(Y)
INIT_CLASS_FUNC(Z)
static void init_shared_classes(void)
{
init_class_X(&lock_X1, &rwlock_X1, &mutex_X1, &rwsem_X1);
init_class_X(&lock_X2, &rwlock_X2, &mutex_X2, &rwsem_X2);
init_class_Y(&lock_Y1, &rwlock_Y1, &mutex_Y1, &rwsem_Y1);
init_class_Y(&lock_Y2, &rwlock_Y2, &mutex_Y2, &rwsem_Y2);
init_class_Z(&lock_Z1, &rwlock_Z1, &mutex_Z1, &rwsem_Z1);
init_class_Z(&lock_Z2, &rwlock_Z2, &mutex_Z2, &rwsem_Z2);
}
/*
* For spinlocks and rwlocks we also do hardirq-safe / softirq-safe tests.
* The following functions use a lock from a simulated hardirq/softirq
* context, causing the locks to be marked as hardirq-safe/softirq-safe:
*/
#define HARDIRQ_DISABLE local_irq_disable
#define HARDIRQ_ENABLE local_irq_enable
#define HARDIRQ_ENTER() \
local_irq_disable(); \
__irq_enter(); \
WARN_ON(!in_irq());
#define HARDIRQ_EXIT() \
__irq_exit(); \
local_irq_enable();
#define SOFTIRQ_DISABLE local_bh_disable
#define SOFTIRQ_ENABLE local_bh_enable
#define SOFTIRQ_ENTER() \
local_bh_disable(); \
local_irq_disable(); \
lockdep_softirq_enter(); \
WARN_ON(!in_softirq());
#define SOFTIRQ_EXIT() \
lockdep_softirq_exit(); \
local_irq_enable(); \
local_bh_enable();
/*
* Shortcuts for lock/unlock API variants, to keep
* the testcases compact:
*/
#define L(x) spin_lock(&lock_##x)
#define U(x) spin_unlock(&lock_##x)
#define LU(x) L(x); U(x)
#define SI(x) spin_lock_init(&lock_##x)
#define WL(x) write_lock(&rwlock_##x)
#define WU(x) write_unlock(&rwlock_##x)
#define WLU(x) WL(x); WU(x)
#define RL(x) read_lock(&rwlock_##x)
#define RU(x) read_unlock(&rwlock_##x)
#define RLU(x) RL(x); RU(x)
#define RWI(x) rwlock_init(&rwlock_##x)
#define ML(x) mutex_lock(&mutex_##x)
#define MU(x) mutex_unlock(&mutex_##x)
#define MI(x) mutex_init(&mutex_##x)
#define WSL(x) down_write(&rwsem_##x)
#define WSU(x) up_write(&rwsem_##x)
#define RSL(x) down_read(&rwsem_##x)
#define RSU(x) up_read(&rwsem_##x)
#define RWSI(x) init_rwsem(&rwsem_##x)
#define LOCK_UNLOCK_2(x,y) LOCK(x); LOCK(y); UNLOCK(y); UNLOCK(x)
/*
* Generate different permutations of the same testcase, using
* the same basic lock-dependency/state events:
*/
#define GENERATE_TESTCASE(name) \
\
static void name(void) { E(); }
#define GENERATE_PERMUTATIONS_2_EVENTS(name) \
\
static void name##_12(void) { E1(); E2(); } \
static void name##_21(void) { E2(); E1(); }
#define GENERATE_PERMUTATIONS_3_EVENTS(name) \
\
static void name##_123(void) { E1(); E2(); E3(); } \
static void name##_132(void) { E1(); E3(); E2(); } \
static void name##_213(void) { E2(); E1(); E3(); } \
static void name##_231(void) { E2(); E3(); E1(); } \
static void name##_312(void) { E3(); E1(); E2(); } \
static void name##_321(void) { E3(); E2(); E1(); }
/*
* AA deadlock:
*/
#define E() \
\
LOCK(X1); \
LOCK(X2); /* this one should fail */
/*
* 6 testcases:
*/
#include "locking-selftest-spin.h"
GENERATE_TESTCASE(AA_spin)
#include "locking-selftest-wlock.h"
GENERATE_TESTCASE(AA_wlock)
#include "locking-selftest-rlock.h"
GENERATE_TESTCASE(AA_rlock)
#include "locking-selftest-mutex.h"
GENERATE_TESTCASE(AA_mutex)
#include "locking-selftest-wsem.h"
GENERATE_TESTCASE(AA_wsem)
#include "locking-selftest-rsem.h"
GENERATE_TESTCASE(AA_rsem)
#undef E
/*
* Special-case for read-locking, they are
* allowed to recurse on the same lock class:
*/
static void rlock_AA1(void)
{
RL(X1);
RL(X1); // this one should NOT fail
}
static void rlock_AA1B(void)
{
RL(X1);
RL(X2); // this one should NOT fail
}
static void rsem_AA1(void)
{
RSL(X1);
RSL(X1); // this one should fail
}
static void rsem_AA1B(void)
{
RSL(X1);
RSL(X2); // this one should fail
}
/*
* The mixing of read and write locks is not allowed:
*/
static void rlock_AA2(void)
{
RL(X1);
WL(X2); // this one should fail
}
static void rsem_AA2(void)
{
RSL(X1);
WSL(X2); // this one should fail
}
static void rlock_AA3(void)
{
WL(X1);
RL(X2); // this one should fail
}
static void rsem_AA3(void)
{
WSL(X1);
RSL(X2); // this one should fail
}
/*
* ABBA deadlock:
*/
#define E() \
\
LOCK_UNLOCK_2(A, B); \
LOCK_UNLOCK_2(B, A); /* fail */
/*
* 6 testcases:
*/
#include "locking-selftest-spin.h"
GENERATE_TESTCASE(ABBA_spin)
#include "locking-selftest-wlock.h"
GENERATE_TESTCASE(ABBA_wlock)
#include "locking-selftest-rlock.h"
GENERATE_TESTCASE(ABBA_rlock)
#include "locking-selftest-mutex.h"
GENERATE_TESTCASE(ABBA_mutex)
#include "locking-selftest-wsem.h"
GENERATE_TESTCASE(ABBA_wsem)
#include "locking-selftest-rsem.h"
GENERATE_TESTCASE(ABBA_rsem)
#undef E
/*
* AB BC CA deadlock:
*/
#define E() \
\
LOCK_UNLOCK_2(A, B); \
LOCK_UNLOCK_2(B, C); \
LOCK_UNLOCK_2(C, A); /* fail */
/*
* 6 testcases:
*/
#include "locking-selftest-spin.h"
GENERATE_TESTCASE(ABBCCA_spin)
#include "locking-selftest-wlock.h"
GENERATE_TESTCASE(ABBCCA_wlock)
#include "locking-selftest-rlock.h"
GENERATE_TESTCASE(ABBCCA_rlock)
#include "locking-selftest-mutex.h"
GENERATE_TESTCASE(ABBCCA_mutex)
#include "locking-selftest-wsem.h"
GENERATE_TESTCASE(ABBCCA_wsem)
#include "locking-selftest-rsem.h"
GENERATE_TESTCASE(ABBCCA_rsem)
#undef E
/*
* AB CA BC deadlock:
*/
#define E() \
\
LOCK_UNLOCK_2(A, B); \
LOCK_UNLOCK_2(C, A); \
LOCK_UNLOCK_2(B, C); /* fail */
/*
* 6 testcases:
*/
#include "locking-selftest-spin.h"
GENERATE_TESTCASE(ABCABC_spin)
#include "locking-selftest-wlock.h"
GENERATE_TESTCASE(ABCABC_wlock)
#include "locking-selftest-rlock.h"
GENERATE_TESTCASE(ABCABC_rlock)
#include "locking-selftest-mutex.h"
GENERATE_TESTCASE(ABCABC_mutex)
#include "locking-selftest-wsem.h"
GENERATE_TESTCASE(ABCABC_wsem)
#include "locking-selftest-rsem.h"
GENERATE_TESTCASE(ABCABC_rsem)
#undef E
/*
* AB BC CD DA deadlock:
*/
#define E() \
\
LOCK_UNLOCK_2(A, B); \
LOCK_UNLOCK_2(B, C); \
LOCK_UNLOCK_2(C, D); \
LOCK_UNLOCK_2(D, A); /* fail */
/*
* 6 testcases:
*/
#include "locking-selftest-spin.h"
GENERATE_TESTCASE(ABBCCDDA_spin)
#include "locking-selftest-wlock.h"
GENERATE_TESTCASE(ABBCCDDA_wlock)
#include "locking-selftest-rlock.h"
GENERATE_TESTCASE(ABBCCDDA_rlock)
#include "locking-selftest-mutex.h"
GENERATE_TESTCASE(ABBCCDDA_mutex)
#include "locking-selftest-wsem.h"
GENERATE_TESTCASE(ABBCCDDA_wsem)
#include "locking-selftest-rsem.h"
GENERATE_TESTCASE(ABBCCDDA_rsem)
#undef E
/*
* AB CD BD DA deadlock:
*/
#define E() \
\
LOCK_UNLOCK_2(A, B); \
LOCK_UNLOCK_2(C, D); \
LOCK_UNLOCK_2(B, D); \
LOCK_UNLOCK_2(D, A); /* fail */
/*
* 6 testcases:
*/
#include "locking-selftest-spin.h"
GENERATE_TESTCASE(ABCDBDDA_spin)
#include "locking-selftest-wlock.h"
GENERATE_TESTCASE(ABCDBDDA_wlock)
#include "locking-selftest-rlock.h"
GENERATE_TESTCASE(ABCDBDDA_rlock)
#include "locking-selftest-mutex.h"
GENERATE_TESTCASE(ABCDBDDA_mutex)
#include "locking-selftest-wsem.h"
GENERATE_TESTCASE(ABCDBDDA_wsem)
#include "locking-selftest-rsem.h"
GENERATE_TESTCASE(ABCDBDDA_rsem)
#undef E
/*
* AB CD BC DA deadlock:
*/
#define E() \
\
LOCK_UNLOCK_2(A, B); \
LOCK_UNLOCK_2(C, D); \
LOCK_UNLOCK_2(B, C); \
LOCK_UNLOCK_2(D, A); /* fail */
/*
* 6 testcases:
*/
#include "locking-selftest-spin.h"
GENERATE_TESTCASE(ABCDBCDA_spin)
#include "locking-selftest-wlock.h"
GENERATE_TESTCASE(ABCDBCDA_wlock)
#include "locking-selftest-rlock.h"
GENERATE_TESTCASE(ABCDBCDA_rlock)
#include "locking-selftest-mutex.h"
GENERATE_TESTCASE(ABCDBCDA_mutex)
#include "locking-selftest-wsem.h"
GENERATE_TESTCASE(ABCDBCDA_wsem)
#include "locking-selftest-rsem.h"
GENERATE_TESTCASE(ABCDBCDA_rsem)
#undef E
/*
* Double unlock:
*/
#define E() \
\
LOCK(A); \
UNLOCK(A); \
UNLOCK(A); /* fail */
/*
* 6 testcases:
*/
#include "locking-selftest-spin.h"
GENERATE_TESTCASE(double_unlock_spin)
#include "locking-selftest-wlock.h"
GENERATE_TESTCASE(double_unlock_wlock)
#include "locking-selftest-rlock.h"
GENERATE_TESTCASE(double_unlock_rlock)
#include "locking-selftest-mutex.h"
GENERATE_TESTCASE(double_unlock_mutex)
#include "locking-selftest-wsem.h"
GENERATE_TESTCASE(double_unlock_wsem)
#include "locking-selftest-rsem.h"
GENERATE_TESTCASE(double_unlock_rsem)
#undef E
/*
* Bad unlock ordering:
*/
#define E() \
\
LOCK(A); \
LOCK(B); \
UNLOCK(A); /* fail */ \
UNLOCK(B);
/*
* 6 testcases:
*/
#include "locking-selftest-spin.h"
GENERATE_TESTCASE(bad_unlock_order_spin)
#include "locking-selftest-wlock.h"
GENERATE_TESTCASE(bad_unlock_order_wlock)
#include "locking-selftest-rlock.h"
GENERATE_TESTCASE(bad_unlock_order_rlock)
#include "locking-selftest-mutex.h"
GENERATE_TESTCASE(bad_unlock_order_mutex)
#include "locking-selftest-wsem.h"
GENERATE_TESTCASE(bad_unlock_order_wsem)
#include "locking-selftest-rsem.h"
GENERATE_TESTCASE(bad_unlock_order_rsem)
#undef E
/*
* initializing a held lock:
*/
#define E() \
\
LOCK(A); \
INIT(A); /* fail */
/*
* 6 testcases:
*/
#include "locking-selftest-spin.h"
GENERATE_TESTCASE(init_held_spin)
#include "locking-selftest-wlock.h"
GENERATE_TESTCASE(init_held_wlock)
#include "locking-selftest-rlock.h"
GENERATE_TESTCASE(init_held_rlock)
#include "locking-selftest-mutex.h"
GENERATE_TESTCASE(init_held_mutex)
#include "locking-selftest-wsem.h"
GENERATE_TESTCASE(init_held_wsem)
#include "locking-selftest-rsem.h"
GENERATE_TESTCASE(init_held_rsem)
#undef E
/*
* locking an irq-safe lock with irqs enabled:
*/
#define E1() \
\
IRQ_ENTER(); \
LOCK(A); \
UNLOCK(A); \
IRQ_EXIT();
#define E2() \
\
LOCK(A); \
UNLOCK(A);
/*
* Generate 24 testcases:
*/
#include "locking-selftest-spin-hardirq.h"
GENERATE_PERMUTATIONS_2_EVENTS(irqsafe1_hard_spin)
#include "locking-selftest-rlock-hardirq.h"
GENERATE_PERMUTATIONS_2_EVENTS(irqsafe1_hard_rlock)
#include "locking-selftest-wlock-hardirq.h"
GENERATE_PERMUTATIONS_2_EVENTS(irqsafe1_hard_wlock)
#include "locking-selftest-spin-softirq.h"
GENERATE_PERMUTATIONS_2_EVENTS(irqsafe1_soft_spin)
#include "locking-selftest-rlock-softirq.h"
GENERATE_PERMUTATIONS_2_EVENTS(irqsafe1_soft_rlock)
#include "locking-selftest-wlock-softirq.h"
GENERATE_PERMUTATIONS_2_EVENTS(irqsafe1_soft_wlock)
#undef E1
#undef E2
/*
* Enabling hardirqs with a softirq-safe lock held:
*/
#define E1() \
\
SOFTIRQ_ENTER(); \
LOCK(A); \
UNLOCK(A); \
SOFTIRQ_EXIT();
#define E2() \
\
HARDIRQ_DISABLE(); \
LOCK(A); \
HARDIRQ_ENABLE(); \
UNLOCK(A);
/*
* Generate 12 testcases:
*/
#include "locking-selftest-spin.h"
GENERATE_PERMUTATIONS_2_EVENTS(irqsafe2A_spin)
#include "locking-selftest-wlock.h"
GENERATE_PERMUTATIONS_2_EVENTS(irqsafe2A_wlock)
#include "locking-selftest-rlock.h"
GENERATE_PERMUTATIONS_2_EVENTS(irqsafe2A_rlock)
#undef E1
#undef E2
/*
* Enabling irqs with an irq-safe lock held:
*/
#define E1() \
\
IRQ_ENTER(); \
LOCK(A); \
UNLOCK(A); \
IRQ_EXIT();
#define E2() \
\
IRQ_DISABLE(); \
LOCK(A); \
IRQ_ENABLE(); \
UNLOCK(A);
/*
* Generate 24 testcases:
*/
#include "locking-selftest-spin-hardirq.h"
GENERATE_PERMUTATIONS_2_EVENTS(irqsafe2B_hard_spin)
#include "locking-selftest-rlock-hardirq.h"
GENERATE_PERMUTATIONS_2_EVENTS(irqsafe2B_hard_rlock)
#include "locking-selftest-wlock-hardirq.h"
GENERATE_PERMUTATIONS_2_EVENTS(irqsafe2B_hard_wlock)
#include "locking-selftest-spin-softirq.h"
GENERATE_PERMUTATIONS_2_EVENTS(irqsafe2B_soft_spin)
#include "locking-selftest-rlock-softirq.h"
GENERATE_PERMUTATIONS_2_EVENTS(irqsafe2B_soft_rlock)
#include "locking-selftest-wlock-softirq.h"
GENERATE_PERMUTATIONS_2_EVENTS(irqsafe2B_soft_wlock)
#undef E1
#undef E2
/*
* Acquiring a irq-unsafe lock while holding an irq-safe-lock:
*/
#define E1() \
\
LOCK(A); \
LOCK(B); \
UNLOCK(B); \
UNLOCK(A); \
#define E2() \
\
LOCK(B); \
UNLOCK(B);
#define E3() \
\
IRQ_ENTER(); \
LOCK(A); \
UNLOCK(A); \
IRQ_EXIT();
/*
* Generate 36 testcases:
*/
#include "locking-selftest-spin-hardirq.h"
GENERATE_PERMUTATIONS_3_EVENTS(irqsafe3_hard_spin)
#include "locking-selftest-rlock-hardirq.h"
GENERATE_PERMUTATIONS_3_EVENTS(irqsafe3_hard_rlock)
#include "locking-selftest-wlock-hardirq.h"
GENERATE_PERMUTATIONS_3_EVENTS(irqsafe3_hard_wlock)
#include "locking-selftest-spin-softirq.h"
GENERATE_PERMUTATIONS_3_EVENTS(irqsafe3_soft_spin)
#include "locking-selftest-rlock-softirq.h"
GENERATE_PERMUTATIONS_3_EVENTS(irqsafe3_soft_rlock)
#include "locking-selftest-wlock-softirq.h"
GENERATE_PERMUTATIONS_3_EVENTS(irqsafe3_soft_wlock)
#undef E1
#undef E2
#undef E3
/*
* If a lock turns into softirq-safe, but earlier it took
* a softirq-unsafe lock:
*/
#define E1() \
IRQ_DISABLE(); \
LOCK(A); \
LOCK(B); \
UNLOCK(B); \
UNLOCK(A); \
IRQ_ENABLE();
#define E2() \
LOCK(B); \
UNLOCK(B);
#define E3() \
IRQ_ENTER(); \
LOCK(A); \
UNLOCK(A); \
IRQ_EXIT();
/*
* Generate 36 testcases:
*/
#include "locking-selftest-spin-hardirq.h"
GENERATE_PERMUTATIONS_3_EVENTS(irqsafe4_hard_spin)
#include "locking-selftest-rlock-hardirq.h"
GENERATE_PERMUTATIONS_3_EVENTS(irqsafe4_hard_rlock)
#include "locking-selftest-wlock-hardirq.h"
GENERATE_PERMUTATIONS_3_EVENTS(irqsafe4_hard_wlock)
#include "locking-selftest-spin-softirq.h"
GENERATE_PERMUTATIONS_3_EVENTS(irqsafe4_soft_spin)
#include "locking-selftest-rlock-softirq.h"
GENERATE_PERMUTATIONS_3_EVENTS(irqsafe4_soft_rlock)
#include "locking-selftest-wlock-softirq.h"
GENERATE_PERMUTATIONS_3_EVENTS(irqsafe4_soft_wlock)
#undef E1
#undef E2
#undef E3
/*
* read-lock / write-lock irq inversion.
*
* Deadlock scenario:
*
* CPU#1 is at #1, i.e. it has write-locked A, but has not
* taken B yet.
*
* CPU#2 is at #2, i.e. it has locked B.
*
* Hardirq hits CPU#2 at point #2 and is trying to read-lock A.
*
* The deadlock occurs because CPU#1 will spin on B, and CPU#2
* will spin on A.
*/
#define E1() \
\
IRQ_DISABLE(); \
WL(A); \
LOCK(B); \
UNLOCK(B); \
WU(A); \
IRQ_ENABLE();
#define E2() \
\
LOCK(B); \
UNLOCK(B);
#define E3() \
\
IRQ_ENTER(); \
RL(A); \
RU(A); \
IRQ_EXIT();
/*
* Generate 36 testcases:
*/
#include "locking-selftest-spin-hardirq.h"
GENERATE_PERMUTATIONS_3_EVENTS(irq_inversion_hard_spin)
#include "locking-selftest-rlock-hardirq.h"
GENERATE_PERMUTATIONS_3_EVENTS(irq_inversion_hard_rlock)
#include "locking-selftest-wlock-hardirq.h"
GENERATE_PERMUTATIONS_3_EVENTS(irq_inversion_hard_wlock)
#include "locking-selftest-spin-softirq.h"
GENERATE_PERMUTATIONS_3_EVENTS(irq_inversion_soft_spin)
#include "locking-selftest-rlock-softirq.h"
GENERATE_PERMUTATIONS_3_EVENTS(irq_inversion_soft_rlock)
#include "locking-selftest-wlock-softirq.h"
GENERATE_PERMUTATIONS_3_EVENTS(irq_inversion_soft_wlock)
#undef E1
#undef E2
#undef E3
/*
* read-lock / write-lock recursion that is actually safe.
*/
#define E1() \
\
IRQ_DISABLE(); \
WL(A); \
WU(A); \
IRQ_ENABLE();
#define E2() \
\
RL(A); \
RU(A); \
#define E3() \
\
IRQ_ENTER(); \
RL(A); \
L(B); \
U(B); \
RU(A); \
IRQ_EXIT();
/*
* Generate 12 testcases:
*/
#include "locking-selftest-hardirq.h"
GENERATE_PERMUTATIONS_3_EVENTS(irq_read_recursion_hard)
#include "locking-selftest-softirq.h"
GENERATE_PERMUTATIONS_3_EVENTS(irq_read_recursion_soft)
#undef E1
#undef E2
#undef E3
/*
* read-lock / write-lock recursion that is unsafe.
*/
#define E1() \
\
IRQ_DISABLE(); \
L(B); \
WL(A); \
WU(A); \
U(B); \
IRQ_ENABLE();
#define E2() \
\
RL(A); \
RU(A); \
#define E3() \
\
IRQ_ENTER(); \
L(B); \
U(B); \
IRQ_EXIT();
/*
* Generate 12 testcases:
*/
#include "locking-selftest-hardirq.h"
// GENERATE_PERMUTATIONS_3_EVENTS(irq_read_recursion2_hard)
#include "locking-selftest-softirq.h"
// GENERATE_PERMUTATIONS_3_EVENTS(irq_read_recursion2_soft)
#ifdef CONFIG_DEBUG_LOCK_ALLOC
# define I_SPINLOCK(x) lockdep_reset_lock(&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)
#else
# define I_SPINLOCK(x)
# define I_RWLOCK(x)
# define I_MUTEX(x)
# define I_RWSEM(x)
#endif
#define I1(x) \
do { \
I_SPINLOCK(x); \
I_RWLOCK(x); \
I_MUTEX(x); \
I_RWSEM(x); \
} while (0)
#define I2(x) \
do { \
spin_lock_init(&lock_##x); \
rwlock_init(&rwlock_##x); \
mutex_init(&mutex_##x); \
init_rwsem(&rwsem_##x); \
} while (0)
static void reset_locks(void)
{
local_irq_disable();
I1(A); I1(B); I1(C); I1(D);
I1(X1); I1(X2); I1(Y1); I1(Y2); I1(Z1); I1(Z2);
lockdep_reset();
I2(A); I2(B); I2(C); I2(D);
init_shared_classes();
local_irq_enable();
}
#undef I
static int testcase_total;
static int testcase_successes;
static int expected_testcase_failures;
static int unexpected_testcase_failures;
static void dotest(void (*testcase_fn)(void), int expected, int lockclass_mask)
{
unsigned long saved_preempt_count = preempt_count();
int expected_failure = 0;
WARN_ON(irqs_disabled());
testcase_fn();
/*
* Filter out expected failures:
*/
#ifndef CONFIG_PROVE_LOCKING
if ((lockclass_mask & LOCKTYPE_SPIN) && debug_locks != expected)
expected_failure = 1;
if ((lockclass_mask & LOCKTYPE_RWLOCK) && debug_locks != expected)
expected_failure = 1;
if ((lockclass_mask & LOCKTYPE_MUTEX) && debug_locks != expected)
expected_failure = 1;
if ((lockclass_mask & LOCKTYPE_RWSEM) && debug_locks != expected)
expected_failure = 1;
#endif
if (debug_locks != expected) {
if (expected_failure) {
expected_testcase_failures++;
printk("failed|");
} else {
unexpected_testcase_failures++;
printk("FAILED|");
dump_stack();
}
} else {
testcase_successes++;
printk(" ok |");
}
testcase_total++;
if (debug_locks_verbose)
printk(" lockclass mask: %x, debug_locks: %d, expected: %d\n",
lockclass_mask, debug_locks, expected);
/*
* Some tests (e.g. double-unlock) might corrupt the preemption
* count, so restore it:
*/
preempt_count() = saved_preempt_count;
#ifdef CONFIG_TRACE_IRQFLAGS
if (softirq_count())
current->softirqs_enabled = 0;
else
current->softirqs_enabled = 1;
#endif
reset_locks();
}
static inline void print_testname(const char *testname)
{
printk("%33s:", testname);
}
#define DO_TESTCASE_1(desc, name, nr) \
print_testname(desc"/"#nr); \
dotest(name##_##nr, SUCCESS, LOCKTYPE_RWLOCK); \
printk("\n");
#define DO_TESTCASE_1B(desc, name, nr) \
print_testname(desc"/"#nr); \
dotest(name##_##nr, FAILURE, LOCKTYPE_RWLOCK); \
printk("\n");
#define DO_TESTCASE_3(desc, name, nr) \
print_testname(desc"/"#nr); \
dotest(name##_spin_##nr, FAILURE, LOCKTYPE_SPIN); \
dotest(name##_wlock_##nr, FAILURE, LOCKTYPE_RWLOCK); \
dotest(name##_rlock_##nr, SUCCESS, LOCKTYPE_RWLOCK); \
printk("\n");
#define DO_TESTCASE_3RW(desc, name, nr) \
print_testname(desc"/"#nr); \
dotest(name##_spin_##nr, FAILURE, LOCKTYPE_SPIN|LOCKTYPE_RWLOCK);\
dotest(name##_wlock_##nr, FAILURE, LOCKTYPE_RWLOCK); \
dotest(name##_rlock_##nr, SUCCESS, LOCKTYPE_RWLOCK); \
printk("\n");
#define DO_TESTCASE_6(desc, name) \
print_testname(desc); \
dotest(name##_spin, FAILURE, LOCKTYPE_SPIN); \
dotest(name##_wlock, FAILURE, LOCKTYPE_RWLOCK); \
dotest(name##_rlock, FAILURE, LOCKTYPE_RWLOCK); \
dotest(name##_mutex, FAILURE, LOCKTYPE_MUTEX); \
dotest(name##_wsem, FAILURE, LOCKTYPE_RWSEM); \
dotest(name##_rsem, FAILURE, LOCKTYPE_RWSEM); \
printk("\n");
#define DO_TESTCASE_6_SUCCESS(desc, name) \
print_testname(desc); \
dotest(name##_spin, SUCCESS, LOCKTYPE_SPIN); \
dotest(name##_wlock, SUCCESS, LOCKTYPE_RWLOCK); \
dotest(name##_rlock, SUCCESS, LOCKTYPE_RWLOCK); \
dotest(name##_mutex, SUCCESS, LOCKTYPE_MUTEX); \
dotest(name##_wsem, SUCCESS, LOCKTYPE_RWSEM); \
dotest(name##_rsem, SUCCESS, LOCKTYPE_RWSEM); \
printk("\n");
/*
* 'read' variant: rlocks must not trigger.
*/
#define DO_TESTCASE_6R(desc, name) \
print_testname(desc); \
dotest(name##_spin, FAILURE, LOCKTYPE_SPIN); \
dotest(name##_wlock, FAILURE, LOCKTYPE_RWLOCK); \
dotest(name##_rlock, SUCCESS, LOCKTYPE_RWLOCK); \
dotest(name##_mutex, FAILURE, LOCKTYPE_MUTEX); \
dotest(name##_wsem, FAILURE, LOCKTYPE_RWSEM); \
dotest(name##_rsem, FAILURE, LOCKTYPE_RWSEM); \
printk("\n");
#define DO_TESTCASE_2I(desc, name, nr) \
DO_TESTCASE_1("hard-"desc, name##_hard, nr); \
DO_TESTCASE_1("soft-"desc, name##_soft, nr);
#define DO_TESTCASE_2IB(desc, name, nr) \
DO_TESTCASE_1B("hard-"desc, name##_hard, nr); \
DO_TESTCASE_1B("soft-"desc, name##_soft, nr);
#define DO_TESTCASE_6I(desc, name, nr) \
DO_TESTCASE_3("hard-"desc, name##_hard, nr); \
DO_TESTCASE_3("soft-"desc, name##_soft, nr);
#define DO_TESTCASE_6IRW(desc, name, nr) \
DO_TESTCASE_3RW("hard-"desc, name##_hard, nr); \
DO_TESTCASE_3RW("soft-"desc, name##_soft, nr);
#define DO_TESTCASE_2x3(desc, name) \
DO_TESTCASE_3(desc, name, 12); \
DO_TESTCASE_3(desc, name, 21);
#define DO_TESTCASE_2x6(desc, name) \
DO_TESTCASE_6I(desc, name, 12); \
DO_TESTCASE_6I(desc, name, 21);
#define DO_TESTCASE_6x2(desc, name) \
DO_TESTCASE_2I(desc, name, 123); \
DO_TESTCASE_2I(desc, name, 132); \
DO_TESTCASE_2I(desc, name, 213); \
DO_TESTCASE_2I(desc, name, 231); \
DO_TESTCASE_2I(desc, name, 312); \
DO_TESTCASE_2I(desc, name, 321);
#define DO_TESTCASE_6x2B(desc, name) \
DO_TESTCASE_2IB(desc, name, 123); \
DO_TESTCASE_2IB(desc, name, 132); \
DO_TESTCASE_2IB(desc, name, 213); \
DO_TESTCASE_2IB(desc, name, 231); \
DO_TESTCASE_2IB(desc, name, 312); \
DO_TESTCASE_2IB(desc, name, 321);
#define DO_TESTCASE_6x6(desc, name) \
DO_TESTCASE_6I(desc, name, 123); \
DO_TESTCASE_6I(desc, name, 132); \
DO_TESTCASE_6I(desc, name, 213); \
DO_TESTCASE_6I(desc, name, 231); \
DO_TESTCASE_6I(desc, name, 312); \
DO_TESTCASE_6I(desc, name, 321);
#define DO_TESTCASE_6x6RW(desc, name) \
DO_TESTCASE_6IRW(desc, name, 123); \
DO_TESTCASE_6IRW(desc, name, 132); \
DO_TESTCASE_6IRW(desc, name, 213); \
DO_TESTCASE_6IRW(desc, name, 231); \
DO_TESTCASE_6IRW(desc, name, 312); \
DO_TESTCASE_6IRW(desc, name, 321);
void locking_selftest(void)
{
/*
* Got a locking failure before the selftest ran?
*/
if (!debug_locks) {
printk("----------------------------------\n");
printk("| Locking API testsuite disabled |\n");
printk("----------------------------------\n");
return;
}
/*
* Run the testsuite:
*/
printk("------------------------\n");
printk("| Locking API testsuite:\n");
printk("----------------------------------------------------------------------------\n");
printk(" | spin |wlock |rlock |mutex | wsem | rsem |\n");
printk(" --------------------------------------------------------------------------\n");
init_shared_classes();
debug_locks_silent = !debug_locks_verbose;
DO_TESTCASE_6R("A-A deadlock", AA);
DO_TESTCASE_6R("A-B-B-A deadlock", ABBA);
DO_TESTCASE_6R("A-B-B-C-C-A deadlock", ABBCCA);
DO_TESTCASE_6R("A-B-C-A-B-C deadlock", ABCABC);
DO_TESTCASE_6R("A-B-B-C-C-D-D-A deadlock", ABBCCDDA);
DO_TESTCASE_6R("A-B-C-D-B-D-D-A deadlock", ABCDBDDA);
DO_TESTCASE_6R("A-B-C-D-B-C-D-A deadlock", ABCDBCDA);
DO_TESTCASE_6("double unlock", double_unlock);
DO_TESTCASE_6("initialize held", init_held);
DO_TESTCASE_6_SUCCESS("bad unlock order", bad_unlock_order);
printk(" --------------------------------------------------------------------------\n");
print_testname("recursive read-lock");
printk(" |");
dotest(rlock_AA1, SUCCESS, LOCKTYPE_RWLOCK);
printk(" |");
dotest(rsem_AA1, FAILURE, LOCKTYPE_RWSEM);
printk("\n");
print_testname("recursive read-lock #2");
printk(" |");
dotest(rlock_AA1B, SUCCESS, LOCKTYPE_RWLOCK);
printk(" |");
dotest(rsem_AA1B, FAILURE, LOCKTYPE_RWSEM);
printk("\n");
print_testname("mixed read-write-lock");
printk(" |");
dotest(rlock_AA2, FAILURE, LOCKTYPE_RWLOCK);
printk(" |");
dotest(rsem_AA2, FAILURE, LOCKTYPE_RWSEM);
printk("\n");
print_testname("mixed write-read-lock");
printk(" |");
dotest(rlock_AA3, FAILURE, LOCKTYPE_RWLOCK);
printk(" |");
dotest(rsem_AA3, FAILURE, LOCKTYPE_RWSEM);
printk("\n");
printk(" --------------------------------------------------------------------------\n");
/*
* irq-context testcases:
*/
DO_TESTCASE_2x6("irqs-on + irq-safe-A", irqsafe1);
DO_TESTCASE_2x3("sirq-safe-A => hirqs-on", irqsafe2A);
DO_TESTCASE_2x6("safe-A + irqs-on", irqsafe2B);
DO_TESTCASE_6x6("safe-A + unsafe-B #1", irqsafe3);
DO_TESTCASE_6x6("safe-A + unsafe-B #2", irqsafe4);
DO_TESTCASE_6x6RW("irq lock-inversion", irq_inversion);
DO_TESTCASE_6x2("irq read-recursion", irq_read_recursion);
// DO_TESTCASE_6x2B("irq read-recursion #2", irq_read_recursion2);
if (unexpected_testcase_failures) {
printk("-----------------------------------------------------------------\n");
debug_locks = 0;
printk("BUG: %3d unexpected failures (out of %3d) - debugging disabled! |\n",
unexpected_testcase_failures, testcase_total);
printk("-----------------------------------------------------------------\n");
} else if (expected_testcase_failures && testcase_successes) {
printk("--------------------------------------------------------\n");
printk("%3d out of %3d testcases failed, as expected. |\n",
expected_testcase_failures, testcase_total);
printk("----------------------------------------------------\n");
debug_locks = 1;
} else if (expected_testcase_failures && !testcase_successes) {
printk("--------------------------------------------------------\n");
printk("All %3d testcases failed, as expected. |\n",
expected_testcase_failures);
printk("----------------------------------------\n");
debug_locks = 1;
} else {
printk("-------------------------------------------------------\n");
printk("Good, all %3d testcases passed! |\n",
testcase_successes);
printk("---------------------------------\n");
debug_locks = 1;
}
debug_locks_silent = 0;
}
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