lockdep: fix irqs on/off ip tracing

Impact: fix lockdep lock-api-caller output when irqsoff tracing is enabled

81d68a96 "ftrace: trace irq disabled critical timings" added wrappers around
trace_hardirqs_on/off_caller. However these functions use
__builtin_return_address(0) to figure out which function actually disabled
or enabled irqs. The result is that we save the ips of trace_hardirqs_on/off
instead of the real caller. Not very helpful.

However since the patch from Steven the ip already gets passed. So use that
and get rid of __builtin_return_address(0) in these two functions.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 5 insertions, 7 deletions

diff --git a/kernel/lockdep.c b/kernel/lockdep.c
index 11832acdde7..06e157119d2 100644
--- a/kernel/lockdep.c
+++ b/kernel/lockdep.c
@@ -2169,12 +2169,11 @@ void early_boot_irqs_on(void)
 /*
  * Hardirqs will be enabled:
  */
-void trace_hardirqs_on_caller(unsigned long a0)
+void trace_hardirqs_on_caller(unsigned long ip)
 {
         struct task_struct *curr = current;
-        unsigned long ip;
 
-        time_hardirqs_on(CALLER_ADDR0, a0);
+        time_hardirqs_on(CALLER_ADDR0, ip);
 
         if (unlikely(!debug_locks || current->lockdep_recursion))
                 return;
@@ -2188,7 +2187,6 @@ void trace_hardirqs_on_caller(unsigned long a0)
         }
         /* we'll do an OFF -> ON transition: */
         curr->hardirqs_enabled = 1;
-        ip = (unsigned long) __builtin_return_address(0);
 
         if (DEBUG_LOCKS_WARN_ON(!irqs_disabled()))
                 return;
@@ -2224,11 +2222,11 @@ EXPORT_SYMBOL(trace_hardirqs_on);
 /*
  * Hardirqs were disabled:
  */
-void trace_hardirqs_off_caller(unsigned long a0)
+void trace_hardirqs_off_caller(unsigned long ip)
 {
         struct task_struct *curr = current;
 
-        time_hardirqs_off(CALLER_ADDR0, a0);
+        time_hardirqs_off(CALLER_ADDR0, ip);
 
         if (unlikely(!debug_locks || current->lockdep_recursion))
                 return;
@@ -2241,7 +2239,7 @@ void trace_hardirqs_off_caller(unsigned long a0)
                  * We have done an ON -> OFF transition:
                  */
                 curr->hardirqs_enabled = 0;
-                curr->hardirq_disable_ip = _RET_IP_;
+                curr->hardirq_disable_ip = ip;
                 curr->hardirq_disable_event = ++curr->irq_events;
                 debug_atomic_inc(&hardirqs_off_events);
         } else