Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull locking updates from Ingo Molnar:

 - Add 'cross-release' support to lockdep, which allows APIs like
   completions, where it's not the 'owner' who releases the lock, to be
   tracked. It's all activated automatically under
   CONFIG_PROVE_LOCKING=y.

 - Clean up (restructure) the x86 atomics op implementation to be more
   readable, in preparation of KASAN annotations. (Dmitry Vyukov)

 - Fix static keys (Paolo Bonzini)

 - Add killable versions of down_read() et al (Kirill Tkhai)

 - Rework and fix jump_label locking (Marc Zyngier, Paolo Bonzini)

 - Rework (and fix) tlb_flush_pending() barriers (Peter Zijlstra)

 - Remove smp_mb__before_spinlock() and convert its usages, introduce
   smp_mb__after_spinlock() (Peter Zijlstra)

* 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (56 commits)
  locking/lockdep/selftests: Fix mixed read-write ABBA tests
  sched/completion: Avoid unnecessary stack allocation for COMPLETION_INITIALIZER_ONSTACK()
  acpi/nfit: Fix COMPLETION_INITIALIZER_ONSTACK() abuse
  locking/pvqspinlock: Relax cmpxchg's to improve performance on some architectures
  smp: Avoid using two cache lines for struct call_single_data
  locking/lockdep: Untangle xhlock history save/restore from task independence
  locking/refcounts, x86/asm: Disable CONFIG_ARCH_HAS_REFCOUNT for the time being
  futex: Remove duplicated code and fix undefined behaviour
  Documentation/locking/atomic: Finish the document...
  locking/lockdep: Fix workqueue crossrelease annotation
  workqueue/lockdep: 'Fix' flush_work() annotation
  locking/lockdep/selftests: Add mixed read-write ABBA tests
  mm, locking/barriers: Clarify tlb_flush_pending() barriers
  locking/lockdep: Make CONFIG_LOCKDEP_CROSSRELEASE and CONFIG_LOCKDEP_COMPLETIONS truly non-interactive
  locking/lockdep: Explicitly initialize wq_barrier::done::map
  locking/lockdep: Rename CONFIG_LOCKDEP_COMPLETE to CONFIG_LOCKDEP_COMPLETIONS
  locking/lockdep: Reword title of LOCKDEP_CROSSRELEASE config
  locking/lockdep: Make CONFIG_LOCKDEP_CROSSRELEASE part of CONFIG_PROVE_LOCKING
  locking/refcounts, x86/asm: Implement fast refcount overflow protection
  locking/lockdep: Fix the rollback and overwrite detection logic in crossrelease
  ...

2 files changed, 139 insertions, 2 deletions

diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 2a9a8759752b..7396f5044397 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -1091,6 +1091,8 @@ config PROVE_LOCKING
 	select DEBUG_MUTEXES
 	select DEBUG_RT_MUTEXES if RT_MUTEXES
 	select DEBUG_LOCK_ALLOC
+	select LOCKDEP_CROSSRELEASE
+	select LOCKDEP_COMPLETIONS
 	select TRACE_IRQFLAGS
 	default n
 	help
@@ -1160,6 +1162,22 @@ config LOCK_STAT
 	 CONFIG_LOCK_STAT defines "contended" and "acquired" lock events.
 	 (CONFIG_LOCKDEP defines "acquire" and "release" events.)
 
+config LOCKDEP_CROSSRELEASE
+	bool
+	help
+	 This makes lockdep work for crosslock which is a lock allowed to
+	 be released in a different context from the acquisition context.
+	 Normally a lock must be released in the context acquiring the lock.
+	 However, relexing this constraint helps synchronization primitives
+	 such as page locks or completions can use the lock correctness
+	 detector, lockdep.
+
+config LOCKDEP_COMPLETIONS
+	bool
+	help
+	 A deadlock caused by wait_for_completion() and complete() can be
+	 detected by lockdep using crossrelease feature.
+
 config DEBUG_LOCKDEP
 	bool "Lock dependency engine debugging"
 	depends on DEBUG_KERNEL && LOCKDEP
diff --git a/lib/locking-selftest.c b/lib/locking-selftest.c
index 6f2b135dc5e8..cd0b5c964bd0 100644
--- a/lib/locking-selftest.c
+++ b/lib/locking-selftest.c
@@ -363,6 +363,103 @@ static void rsem_AA3(void)
 }
 
 /*
+ * read_lock(A)
+ * spin_lock(B)
+ *		spin_lock(B)
+ *		write_lock(A)
+ */
+static void rlock_ABBA1(void)
+{
+	RL(X1);
+	L(Y1);
+	U(Y1);
+	RU(X1);
+
+	L(Y1);
+	WL(X1);
+	WU(X1);
+	U(Y1); // should fail
+}
+
+static void rwsem_ABBA1(void)
+{
+	RSL(X1);
+	ML(Y1);
+	MU(Y1);
+	RSU(X1);
+
+	ML(Y1);
+	WSL(X1);
+	WSU(X1);
+	MU(Y1); // should fail
+}
+
+/*
+ * read_lock(A)
+ * spin_lock(B)
+ *		spin_lock(B)
+ *		read_lock(A)
+ */
+static void rlock_ABBA2(void)
+{
+	RL(X1);
+	L(Y1);
+	U(Y1);
+	RU(X1);
+
+	L(Y1);
+	RL(X1);
+	RU(X1);
+	U(Y1); // should NOT fail
+}
+
+static void rwsem_ABBA2(void)
+{
+	RSL(X1);
+	ML(Y1);
+	MU(Y1);
+	RSU(X1);
+
+	ML(Y1);
+	RSL(X1);
+	RSU(X1);
+	MU(Y1); // should fail
+}
+
+
+/*
+ * write_lock(A)
+ * spin_lock(B)
+ *		spin_lock(B)
+ *		write_lock(A)
+ */
+static void rlock_ABBA3(void)
+{
+	WL(X1);
+	L(Y1);
+	U(Y1);
+	WU(X1);
+
+	L(Y1);
+	WL(X1);
+	WU(X1);
+	U(Y1); // should fail
+}
+
+static void rwsem_ABBA3(void)
+{
+	WSL(X1);
+	ML(Y1);
+	MU(Y1);
+	WSU(X1);
+
+	ML(Y1);
+	WSL(X1);
+	WSU(X1);
+	MU(Y1); // should fail
+}
+
+/*
  * ABBA deadlock:
  */
 
@@ -1056,8 +1153,6 @@ static void dotest(void (*testcase_fn)(void), int expected, int lockclass_mask)
 	if (debug_locks != expected) {
 		unexpected_testcase_failures++;
 		pr_cont("FAILED|");
-
-		dump_stack();
 	} else {
 		testcase_successes++;
 		pr_cont("  ok  |");
@@ -1933,6 +2028,30 @@ void locking_selftest(void)
 	dotest(rsem_AA3, FAILURE, LOCKTYPE_RWSEM);
 	pr_cont("\n");
 
+	print_testname("mixed read-lock/lock-write ABBA");
+	pr_cont("             |");
+	dotest(rlock_ABBA1, FAILURE, LOCKTYPE_RWLOCK);
+	/*
+	 * Lockdep does indeed fail here, but there's nothing we can do about
+	 * that now.  Don't kill lockdep for it.
+	 */
+	unexpected_testcase_failures--;
+
+	pr_cont("             |");
+	dotest(rwsem_ABBA1, FAILURE, LOCKTYPE_RWSEM);
+
+	print_testname("mixed read-lock/lock-read ABBA");
+	pr_cont("             |");
+	dotest(rlock_ABBA2, SUCCESS, LOCKTYPE_RWLOCK);
+	pr_cont("             |");
+	dotest(rwsem_ABBA2, FAILURE, LOCKTYPE_RWSEM);
+
+	print_testname("mixed write-lock/lock-write ABBA");
+	pr_cont("             |");
+	dotest(rlock_ABBA3, FAILURE, LOCKTYPE_RWLOCK);
+	pr_cont("             |");
+	dotest(rwsem_ABBA3, FAILURE, LOCKTYPE_RWSEM);
+
 	printk("  --------------------------------------------------------------------------\n");
 
 	/*