3 files changed, 82 insertions, 9 deletions

diff --git a/include/linux/smp_lock.h b/include/linux/smp_lock.h
index 813be59bf345..d48cc77ba70d 100644
--- a/include/linux/smp_lock.h
+++ b/include/linux/smp_lock.h
@@ -3,6 +3,7 @@
 
 #ifdef CONFIG_LOCK_KERNEL
 #include <linux/sched.h>
+#include <trace/events/bkl.h>
 
 #define kernel_locked()         (current->lock_depth >= 0)
 
@@ -24,8 +25,18 @@ static inline int reacquire_kernel_lock(struct task_struct *task)
         return 0;
 }
 
-extern void __lockfunc lock_kernel(void)        __acquires(kernel_lock);
-extern void __lockfunc unlock_kernel(void)      __releases(kernel_lock);
+extern void __lockfunc _lock_kernel(void)       __acquires(kernel_lock);
+extern void __lockfunc _unlock_kernel(void)     __releases(kernel_lock);
+
+#define lock_kernel()   {                                       \
+        trace_lock_kernel(__func__, __FILE__, __LINE__);        \
+        _lock_kernel();                                         \
+}
+
+#define unlock_kernel() {                                       \
+        trace_unlock_kernel(__func__, __FILE__, __LINE__);      \
+        _unlock_kernel();                                       \
+}
 
 /*
  * Various legacy drivers don't really need the BKL in a specific
@@ -41,8 +52,8 @@ static inline void cycle_kernel_lock(void)
 
 #else
 
-#define lock_kernel()                           do { } while(0)
-#define unlock_kernel()                         do { } while(0)
+#define lock_kernel()      trace_lock_kernel(__func__, __FILE__, __LINE__);
+#define unlock_kernel()    trace_unlock_kernel(__func__, __FILE__, __LINE__);
 #define release_kernel_lock(task)               do { } while(0)
 #define cycle_kernel_lock()                     do { } while(0)
 #define reacquire_kernel_lock(task)             0
diff --git a/include/trace/events/bkl.h b/include/trace/events/bkl.h
new file mode 100644
index 000000000000..8abd620a490e
--- /dev/null
+++ b/include/trace/events/bkl.h
@@ -0,0 +1,61 @@
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM bkl
+
+#if !defined(_TRACE_BKL_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_BKL_H
+
+#include <linux/tracepoint.h>
+
+TRACE_EVENT(lock_kernel,
+
+        TP_PROTO(const char *func, const char *file, int line),
+
+        TP_ARGS(func, file, line),
+
+        TP_STRUCT__entry(
+                __field(        int,            lock_depth              )
+                __field_ext(    const char *,   func, FILTER_PTR_STRING )
+                __field_ext(    const char *,   file, FILTER_PTR_STRING )
+                __field(        int,            line                    )
+        ),
+
+        TP_fast_assign(
+                /* We want to record the lock_depth after lock is acquired */
+                __entry->lock_depth = current->lock_depth + 1;
+                __entry->func = func;
+                __entry->file = file;
+                __entry->line = line;
+        ),
+
+        TP_printk("depth: %d, %s:%d %s()", __entry->lock_depth,
+                  __entry->file, __entry->line, __entry->func)
+);
+
+TRACE_EVENT(unlock_kernel,
+
+        TP_PROTO(const char *func, const char *file, int line),
+
+        TP_ARGS(func, file, line),
+
+        TP_STRUCT__entry(
+                __field(int,            lock_depth)
+                __field(const char *,   func)
+                __field(const char *,   file)
+                __field(int,            line)
+        ),
+
+        TP_fast_assign(
+                __entry->lock_depth = current->lock_depth;
+                __entry->func = func;
+                __entry->file = file;
+                __entry->line = line;
+        ),
+
+        TP_printk("depth: %d, %s:%d %s()", __entry->lock_depth,
+                  __entry->file, __entry->line, __entry->func)
+);
+
+#endif /* _TRACE_BKL_H */
+
+/* This part must be outside protection */
+#include <trace/define_trace.h>
diff --git a/lib/kernel_lock.c b/lib/kernel_lock.c
index 39f1029e3525..5c10b2e1fd08 100644
--- a/lib/kernel_lock.c
+++ b/lib/kernel_lock.c
@@ -5,10 +5,11 @@
  * relegated to obsolescence, but used by various less
  * important (or lazy) subsystems.
  */
-#include <linux/smp_lock.h>
 #include <linux/module.h>
 #include <linux/kallsyms.h>
 #include <linux/semaphore.h>
+#define CREATE_TRACE_POINTS
+#include <linux/smp_lock.h>
 
 /*
  * The 'big kernel lock'
@@ -113,7 +114,7 @@ static inline void __unlock_kernel(void)
  * This cannot happen asynchronously, so we only need to
  * worry about other CPU's.
  */
-void __lockfunc lock_kernel(void)
+void __lockfunc _lock_kernel(void)
 {
         int depth = current->lock_depth+1;
         if (likely(!depth))
@@ -121,13 +122,13 @@ void __lockfunc lock_kernel(void)
         current->lock_depth = depth;
 }
 
-void __lockfunc unlock_kernel(void)
+void __lockfunc _unlock_kernel(void)
 {
         BUG_ON(current->lock_depth < 0);
         if (likely(--current->lock_depth < 0))
                 __unlock_kernel();
 }
 
-EXPORT_SYMBOL(lock_kernel);
-EXPORT_SYMBOL(unlock_kernel);
+EXPORT_SYMBOL(_lock_kernel);
+EXPORT_SYMBOL(_unlock_kernel);