1 files changed, 23 insertions, 1 deletions

diff --git a/kernel/sched.c b/kernel/sched.c
index 73e600852365..328494e28df2 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -70,6 +70,7 @@
 #include <linux/bootmem.h>
 #include <linux/debugfs.h>
 #include <linux/ctype.h>
+#include <linux/ftrace.h>
 
 #include <asm/tlb.h>
 #include <asm/irq_regs.h>
@@ -4365,26 +4366,44 @@ void scheduler_tick(void)
 #endif
 }
 
-#if defined(CONFIG_PREEMPT) && defined(CONFIG_DEBUG_PREEMPT)
+#if defined(CONFIG_PREEMPT) && (defined(CONFIG_DEBUG_PREEMPT) || \
+                                defined(CONFIG_PREEMPT_TRACER))
+
+static inline unsigned long get_parent_ip(unsigned long addr)
+{
+        if (in_lock_functions(addr)) {
+                addr = CALLER_ADDR2;
+                if (in_lock_functions(addr))
+                        addr = CALLER_ADDR3;
+        }
+        return addr;
+}
 
 void __kprobes add_preempt_count(int val)
 {
+#ifdef CONFIG_DEBUG_PREEMPT
         /*
          * Underflow?
          */
         if (DEBUG_LOCKS_WARN_ON((preempt_count() < 0)))
                 return;
+#endif
         preempt_count() += val;
+#ifdef CONFIG_DEBUG_PREEMPT
         /*
          * Spinlock count overflowing soon?
          */
         DEBUG_LOCKS_WARN_ON((preempt_count() & PREEMPT_MASK) >=
                                 PREEMPT_MASK - 10);
+#endif
+        if (preempt_count() == val)
+                trace_preempt_off(CALLER_ADDR0, get_parent_ip(CALLER_ADDR1));
 }
 EXPORT_SYMBOL(add_preempt_count);
 
 void __kprobes sub_preempt_count(int val)
 {
+#ifdef CONFIG_DEBUG_PREEMPT
         /*
          * Underflow?
          */
@@ -4396,7 +4415,10 @@ void __kprobes sub_preempt_count(int val)
         if (DEBUG_LOCKS_WARN_ON((val < PREEMPT_MASK) &&
                         !(preempt_count() & PREEMPT_MASK)))
                 return;
+#endif
 
+        if (preempt_count() == val)
+                trace_preempt_on(CALLER_ADDR0, get_parent_ip(CALLER_ADDR1));
         preempt_count() -= val;
 }
 EXPORT_SYMBOL(sub_preempt_count);