1 files changed, 5 insertions, 38 deletions

diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c
index 16a571dea2ef..1db0e121a3e7 100644
--- a/arch/x86/kernel/ftrace.c
+++ b/arch/x86/kernel/ftrace.c
@@ -44,62 +44,37 @@ void ftrace_nmi_exit(void)
         atomic_dec(&in_nmi);
 }
 
-/*
- * Synchronize accesses to return adresses stack with
- * interrupts.
- */
-static raw_spinlock_t ret_stack_lock;
-
 /* Add a function return address to the trace stack on thread info.*/
 static int push_return_trace(unsigned long ret, unsigned long long time,
                                 unsigned long func)
 {
         int index;
-        struct thread_info *ti;
-        unsigned long flags;
-        int err = 0;
-
-        raw_local_irq_save(flags);
-        __raw_spin_lock(&ret_stack_lock);
+        struct thread_info *ti = current_thread_info();
 
-        ti = current_thread_info();
         /* The return trace stack is full */
-        if (ti->curr_ret_stack == FTRACE_RET_STACK_SIZE - 1) {
-                err = -EBUSY;
-                goto out;
-        }
+        if (ti->curr_ret_stack == FTRACE_RET_STACK_SIZE - 1)
+                return -EBUSY;
 
         index = ++ti->curr_ret_stack;
         ti->ret_stack[index].ret = ret;
         ti->ret_stack[index].func = func;
         ti->ret_stack[index].calltime = time;
 
-out:
-        __raw_spin_unlock(&ret_stack_lock);
-        raw_local_irq_restore(flags);
-        return err;
+        return 0;
 }
 
 /* Retrieve a function return address to the trace stack on thread info.*/
 static void pop_return_trace(unsigned long *ret, unsigned long long *time,
                                 unsigned long *func)
 {
-        struct thread_info *ti;
         int index;
-        unsigned long flags;
-
-        raw_local_irq_save(flags);
-        __raw_spin_lock(&ret_stack_lock);
 
-        ti = current_thread_info();
+        struct thread_info *ti = current_thread_info();
         index = ti->curr_ret_stack;
         *ret = ti->ret_stack[index].ret;
         *func = ti->ret_stack[index].func;
         *time = ti->ret_stack[index].calltime;
         ti->curr_ret_stack--;
-
-        __raw_spin_unlock(&ret_stack_lock);
-        raw_local_irq_restore(flags);
 }
 
 /*
@@ -175,14 +150,6 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr)
                 *parent = old;
 }
 
-static int __init init_ftrace_function_return(void)
-{
-        ret_stack_lock = (raw_spinlock_t)__RAW_SPIN_LOCK_UNLOCKED;
-        return 0;
-}
-device_initcall(init_ftrace_function_return);
-
-
 #endif
 
 #ifdef CONFIG_DYNAMIC_FTRACE