locking: Move the lockdep code to kernel/locking/

Suggested-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/n/tip-wl7s3tta5isufzfguc23et06@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

5 files changed, 5125 insertions, 0 deletions

diff --git a/kernel/locking/Makefile b/kernel/locking/Makefile
index fe8bd58b22f8..c103599fc1ba 100644
--- a/kernel/locking/Makefile
+++ b/kernel/locking/Makefile
@@ -2,8 +2,14 @@
 obj-y += mutex.o
 
 ifdef CONFIG_FUNCTION_TRACER
+CFLAGS_REMOVE_lockdep.o = -pg
+CFLAGS_REMOVE_lockdep_proc.o = -pg
 CFLAGS_REMOVE_mutex-debug.o = -pg
 CFLAGS_REMOVE_rtmutex-debug.o = -pg
 endif
 
 obj-$(CONFIG_DEBUG_MUTEXES) += mutex-debug.o
+obj-$(CONFIG_LOCKDEP) += lockdep.o
+ifeq ($(CONFIG_PROC_FS),y)
+obj-$(CONFIG_LOCKDEP) += lockdep_proc.o
+endif
diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
new file mode 100644
index 000000000000..4e8e14c34e42
--- /dev/null
+++ b/kernel/locking/lockdep.c
@@ -0,0 +1,4257 @@
+/*
+ * kernel/lockdep.c
+ *
+ * Runtime locking correctness validator
+ *
+ * Started by Ingo Molnar:
+ *
+ *  Copyright (C) 2006,2007 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
+ *  Copyright (C) 2007 Red Hat, Inc., Peter Zijlstra <pzijlstr@redhat.com>
+ *
+ * this code maps all the lock dependencies as they occur in a live kernel
+ * and will warn about the following classes of locking bugs:
+ *
+ * - lock inversion scenarios
+ * - circular lock dependencies
+ * - hardirq/softirq safe/unsafe locking bugs
+ *
+ * Bugs are reported even if the current locking scenario does not cause
+ * any deadlock at this point.
+ *
+ * I.e. if anytime in the past two locks were taken in a different order,
+ * even if it happened for another task, even if those were different
+ * locks (but of the same class as this lock), this code will detect it.
+ *
+ * Thanks to Arjan van de Ven for coming up with the initial idea of
+ * mapping lock dependencies runtime.
+ */
+#define DISABLE_BRANCH_PROFILING
+#include <linux/mutex.h>
+#include <linux/sched.h>
+#include <linux/delay.h>
+#include <linux/module.h>
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
+#include <linux/spinlock.h>
+#include <linux/kallsyms.h>
+#include <linux/interrupt.h>
+#include <linux/stacktrace.h>
+#include <linux/debug_locks.h>
+#include <linux/irqflags.h>
+#include <linux/utsname.h>
+#include <linux/hash.h>
+#include <linux/ftrace.h>
+#include <linux/stringify.h>
+#include <linux/bitops.h>
+#include <linux/gfp.h>
+#include <linux/kmemcheck.h>
+
+#include <asm/sections.h>
+
+#include "lockdep_internals.h"
+
+#define CREATE_TRACE_POINTS
+#include <trace/events/lock.h>
+
+#ifdef CONFIG_PROVE_LOCKING
+int prove_locking = 1;
+module_param(prove_locking, int, 0644);
+#else
+#define prove_locking 0
+#endif
+
+#ifdef CONFIG_LOCK_STAT
+int lock_stat = 1;
+module_param(lock_stat, int, 0644);
+#else
+#define lock_stat 0
+#endif
+
+/*
+ * lockdep_lock: protects the lockdep graph, the hashes and the
+ *               class/list/hash allocators.
+ *
+ * This is one of the rare exceptions where it's justified
+ * to use a raw spinlock - we really dont want the spinlock
+ * code to recurse back into the lockdep code...
+ */
+static arch_spinlock_t lockdep_lock = (arch_spinlock_t)__ARCH_SPIN_LOCK_UNLOCKED;
+
+static int graph_lock(void)
+{
+        arch_spin_lock(&lockdep_lock);
+        /*
+         * Make sure that if another CPU detected a bug while
+         * walking the graph we dont change it (while the other
+         * CPU is busy printing out stuff with the graph lock
+         * dropped already)
+         */
+        if (!debug_locks) {
+                arch_spin_unlock(&lockdep_lock);
+                return 0;
+        }
+        /* prevent any recursions within lockdep from causing deadlocks */
+        current->lockdep_recursion++;
+        return 1;
+}
+
+static inline int graph_unlock(void)
+{
+        if (debug_locks && !arch_spin_is_locked(&lockdep_lock)) {
+                /*
+                 * The lockdep graph lock isn't locked while we expect it to
+                 * be, we're confused now, bye!
+                 */
+                return DEBUG_LOCKS_WARN_ON(1);
+        }
+
+        current->lockdep_recursion--;
+        arch_spin_unlock(&lockdep_lock);
+        return 0;
+}
+
+/*
+ * Turn lock debugging off and return with 0 if it was off already,
+ * and also release the graph lock:
+ */
+static inline int debug_locks_off_graph_unlock(void)
+{
+        int ret = debug_locks_off();
+
+        arch_spin_unlock(&lockdep_lock);
+
+        return ret;
+}
+
+static int lockdep_initialized;
+
+unsigned long nr_list_entries;
+static struct lock_list list_entries[MAX_LOCKDEP_ENTRIES];
+
+/*
+ * All data structures here are protected by the global debug_lock.
+ *
+ * Mutex key structs only get allocated, once during bootup, and never
+ * get freed - this significantly simplifies the debugging code.
+ */
+unsigned long nr_lock_classes;
+static struct lock_class lock_classes[MAX_LOCKDEP_KEYS];
+
+static inline struct lock_class *hlock_class(struct held_lock *hlock)
+{
+        if (!hlock->class_idx) {
+                /*
+                 * Someone passed in garbage, we give up.
+                 */
+                DEBUG_LOCKS_WARN_ON(1);
+                return NULL;
+        }
+        return lock_classes + hlock->class_idx - 1;
+}
+
+#ifdef CONFIG_LOCK_STAT
+static DEFINE_PER_CPU(struct lock_class_stats[MAX_LOCKDEP_KEYS],
+                      cpu_lock_stats);
+
+static inline u64 lockstat_clock(void)
+{
+        return local_clock();
+}
+
+static int lock_point(unsigned long points[], unsigned long ip)
+{
+        int i;
+
+        for (i = 0; i < LOCKSTAT_POINTS; i++) {
+                if (points[i] == 0) {
+                        points[i] = ip;
+                        break;
+                }
+                if (points[i] == ip)
+                        break;
+        }
+
+        return i;