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

Pull core locking changes from Ingo Molnar:
 "It includes a lockdep improvement plus a spinlock inlining Kconfig
  cleanup."

* 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  locking: Adjust spin lock inlining Kconfig options
  lockdep: Check if nested lock is actually held

2 files changed, 102 insertions, 40 deletions

diff --git a/kernel/Kconfig.locks b/kernel/Kconfig.locks
index 2251882daf53..44511d100eaa 100644
--- a/kernel/Kconfig.locks
+++ b/kernel/Kconfig.locks
@@ -87,6 +87,9 @@ config ARCH_INLINE_WRITE_UNLOCK_IRQ
 config ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE
         bool
 
+config UNINLINE_SPIN_UNLOCK
+        bool
+
 #
 # lock_* functions are inlined when:
 #   - DEBUG_SPINLOCK=n and GENERIC_LOCKBREAK=n and ARCH_INLINE_*LOCK=y
@@ -103,100 +106,120 @@ config ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE
 #   - DEBUG_SPINLOCK=n and ARCH_INLINE_*LOCK=y
 #
 
+if !DEBUG_SPINLOCK
+
 config INLINE_SPIN_TRYLOCK
-        def_bool !DEBUG_SPINLOCK && ARCH_INLINE_SPIN_TRYLOCK
+        def_bool y
+        depends on ARCH_INLINE_SPIN_TRYLOCK
 
 config INLINE_SPIN_TRYLOCK_BH
-        def_bool !DEBUG_SPINLOCK && ARCH_INLINE_SPIN_TRYLOCK_BH
+        def_bool y
+        depends on ARCH_INLINE_SPIN_TRYLOCK_BH
 
 config INLINE_SPIN_LOCK
-        def_bool !DEBUG_SPINLOCK && !GENERIC_LOCKBREAK && ARCH_INLINE_SPIN_LOCK
+        def_bool y
+        depends on !GENERIC_LOCKBREAK && ARCH_INLINE_SPIN_LOCK
 
 config INLINE_SPIN_LOCK_BH
-        def_bool !DEBUG_SPINLOCK && !GENERIC_LOCKBREAK && \
-                 ARCH_INLINE_SPIN_LOCK_BH
+        def_bool y
+        depends on !GENERIC_LOCKBREAK && ARCH_INLINE_SPIN_LOCK_BH
 
 config INLINE_SPIN_LOCK_IRQ
-        def_bool !DEBUG_SPINLOCK && !GENERIC_LOCKBREAK && \
-                 ARCH_INLINE_SPIN_LOCK_IRQ
+        def_bool y
+        depends on !GENERIC_LOCKBREAK && ARCH_INLINE_SPIN_LOCK_IRQ
 
 config INLINE_SPIN_LOCK_IRQSAVE
-        def_bool !DEBUG_SPINLOCK && !GENERIC_LOCKBREAK && \
-                 ARCH_INLINE_SPIN_LOCK_IRQSAVE
-
-config UNINLINE_SPIN_UNLOCK
-        bool
+        def_bool y
+        depends on !GENERIC_LOCKBREAK && ARCH_INLINE_SPIN_LOCK_IRQSAVE
 
 config INLINE_SPIN_UNLOCK_BH
-        def_bool !DEBUG_SPINLOCK && ARCH_INLINE_SPIN_UNLOCK_BH
+        def_bool y
+        depends on ARCH_INLINE_SPIN_UNLOCK_BH
 
 config INLINE_SPIN_UNLOCK_IRQ
-        def_bool !DEBUG_SPINLOCK && (!PREEMPT || ARCH_INLINE_SPIN_UNLOCK_BH)
+        def_bool y
+        depends on !PREEMPT || ARCH_INLINE_SPIN_UNLOCK_BH
 
 config INLINE_SPIN_UNLOCK_IRQRESTORE
-        def_bool !DEBUG_SPINLOCK && ARCH_INLINE_SPIN_UNLOCK_IRQRESTORE
+        def_bool y
+        depends on ARCH_INLINE_SPIN_UNLOCK_IRQRESTORE
 
 
 config INLINE_READ_TRYLOCK
-        def_bool !DEBUG_SPINLOCK && ARCH_INLINE_READ_TRYLOCK
+        def_bool y
+        depends on ARCH_INLINE_READ_TRYLOCK
 
 config INLINE_READ_LOCK
-        def_bool !DEBUG_SPINLOCK && !GENERIC_LOCKBREAK && ARCH_INLINE_READ_LOCK
+        def_bool y
+        depends on !GENERIC_LOCKBREAK && ARCH_INLINE_READ_LOCK
 
 config INLINE_READ_LOCK_BH
-        def_bool !DEBUG_SPINLOCK && !GENERIC_LOCKBREAK && \
-                 ARCH_INLINE_READ_LOCK_BH
+        def_bool y
+        depends on !GENERIC_LOCKBREAK && ARCH_INLINE_READ_LOCK_BH
 
 config INLINE_READ_LOCK_IRQ
-        def_bool !DEBUG_SPINLOCK && !GENERIC_LOCKBREAK && \
-                 ARCH_INLINE_READ_LOCK_IRQ
+        def_bool y
+        depends on !GENERIC_LOCKBREAK && ARCH_INLINE_READ_LOCK_IRQ
 
 config INLINE_READ_LOCK_IRQSAVE
-        def_bool !DEBUG_SPINLOCK && !GENERIC_LOCKBREAK && \
-                 ARCH_INLINE_READ_LOCK_IRQSAVE
+        def_bool y
+        depends on !GENERIC_LOCKBREAK && ARCH_INLINE_READ_LOCK_IRQSAVE
 
 config INLINE_READ_UNLOCK
-        def_bool !DEBUG_SPINLOCK && (!PREEMPT || ARCH_INLINE_READ_UNLOCK)
+        def_bool y
+        depends on !PREEMPT || ARCH_INLINE_READ_UNLOCK
 
 config INLINE_READ_UNLOCK_BH
-        def_bool !DEBUG_SPINLOCK && ARCH_INLINE_READ_UNLOCK_BH
+        def_bool y
+        depends on ARCH_INLINE_READ_UNLOCK_BH
 
 config INLINE_READ_UNLOCK_IRQ
-        def_bool !DEBUG_SPINLOCK && (!PREEMPT || ARCH_INLINE_READ_UNLOCK_BH)
+        def_bool y
+        depends on !PREEMPT || ARCH_INLINE_READ_UNLOCK_BH
 
 config INLINE_READ_UNLOCK_IRQRESTORE
-        def_bool !DEBUG_SPINLOCK && ARCH_INLINE_READ_UNLOCK_IRQRESTORE
+        def_bool y
+        depends on ARCH_INLINE_READ_UNLOCK_IRQRESTORE
 
 
 config INLINE_WRITE_TRYLOCK
-        def_bool !DEBUG_SPINLOCK && ARCH_INLINE_WRITE_TRYLOCK
+        def_bool y
+        depends on ARCH_INLINE_WRITE_TRYLOCK
 
 config INLINE_WRITE_LOCK
-        def_bool !DEBUG_SPINLOCK && !GENERIC_LOCKBREAK && ARCH_INLINE_WRITE_LOCK
+        def_bool y
+        depends on !GENERIC_LOCKBREAK && ARCH_INLINE_WRITE_LOCK
 
 config INLINE_WRITE_LOCK_BH
-        def_bool !DEBUG_SPINLOCK && !GENERIC_LOCKBREAK && \
-                 ARCH_INLINE_WRITE_LOCK_BH
+        def_bool y
+        depends on !GENERIC_LOCKBREAK && ARCH_INLINE_WRITE_LOCK_BH
 
 config INLINE_WRITE_LOCK_IRQ
-        def_bool !DEBUG_SPINLOCK && !GENERIC_LOCKBREAK && \
-                 ARCH_INLINE_WRITE_LOCK_IRQ
+        def_bool y
+        depends on !GENERIC_LOCKBREAK && ARCH_INLINE_WRITE_LOCK_IRQ
 
 config INLINE_WRITE_LOCK_IRQSAVE
-        def_bool !DEBUG_SPINLOCK && !GENERIC_LOCKBREAK && \
-                 ARCH_INLINE_WRITE_LOCK_IRQSAVE
+        def_bool y
+        depends on !GENERIC_LOCKBREAK && ARCH_INLINE_WRITE_LOCK_IRQSAVE
 
 config INLINE_WRITE_UNLOCK
-        def_bool !DEBUG_SPINLOCK && (!PREEMPT || ARCH_INLINE_WRITE_UNLOCK)
+        def_bool y
+        depends on !PREEMPT || ARCH_INLINE_WRITE_UNLOCK
 
 config INLINE_WRITE_UNLOCK_BH
-        def_bool !DEBUG_SPINLOCK && ARCH_INLINE_WRITE_UNLOCK_BH
+        def_bool y
+        depends on ARCH_INLINE_WRITE_UNLOCK_BH
 
 config INLINE_WRITE_UNLOCK_IRQ
-        def_bool !DEBUG_SPINLOCK && (!PREEMPT || ARCH_INLINE_WRITE_UNLOCK_BH)
+        def_bool y
+        depends on !PREEMPT || ARCH_INLINE_WRITE_UNLOCK_BH
 
 config INLINE_WRITE_UNLOCK_IRQRESTORE
-        def_bool !DEBUG_SPINLOCK && ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE
+        def_bool y
+        depends on ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE
+
+endif
 
 config MUTEX_SPIN_ON_OWNER
-        def_bool SMP && !DEBUG_MUTEXES
+        def_bool y
+        depends on SMP && !DEBUG_MUTEXES
diff --git a/kernel/lockdep.c b/kernel/lockdep.c
index ea9ee4518c35..7981e5b2350d 100644
--- a/kernel/lockdep.c
+++ b/kernel/lockdep.c
@@ -2998,6 +2998,42 @@ EXPORT_SYMBOL_GPL(lockdep_init_map);
 
 struct lock_class_key __lockdep_no_validate__;
 
+static int
+print_lock_nested_lock_not_held(struct task_struct *curr,
+                                struct held_lock *hlock,
+                                unsigned long ip)
+{
+        if (!debug_locks_off())
+                return 0;
+        if (debug_locks_silent)
+                return 0;
+
+        printk("\n");
+        printk("==================================\n");
+        printk("[ BUG: Nested lock was not taken ]\n");
+        print_kernel_ident();
+        printk("----------------------------------\n");
+
+        printk("%s/%d is trying to lock:\n", curr->comm, task_pid_nr(curr));
+        print_lock(hlock);
+
+        printk("\nbut this task is not holding:\n");
+        printk("%s\n", hlock->nest_lock->name);
+
+        printk("\nstack backtrace:\n");
+        dump_stack();
+
+        printk("\nother info that might help us debug this:\n");
+        lockdep_print_held_locks(curr);
+
+        printk("\nstack backtrace:\n");
+        dump_stack();
+
+        return 0;
+}
+
+static int __lock_is_held(struct lockdep_map *lock);
+
 /*
  * This gets called for every mutex_lock*()/spin_lock*() operation.
  * We maintain the dependency maps and validate the locking attempt:
@@ -3139,6 +3175,9 @@ static int __lock_acquire(struct lockdep_map *lock, unsigned int subclass,
         }
         chain_key = iterate_chain_key(chain_key, id);
 
+        if (nest_lock && !__lock_is_held(nest_lock))
+                return print_lock_nested_lock_not_held(curr, hlock, ip);
+
         if (!validate_chain(curr, lock, hlock, chain_head, chain_key))
                 return 0;