4 files changed, 15 insertions, 46 deletions

diff --git a/arch/x86/kernel/entry_32.S b/arch/x86/kernel/entry_32.S
index 9a0ac85946db..f97621149839 100644
--- a/arch/x86/kernel/entry_32.S
+++ b/arch/x86/kernel/entry_32.S
@@ -1217,12 +1217,9 @@ trace_return:
         pushl %eax
         pushl %ecx
         pushl %edx
-        movl 0xc(%esp), %eax
-        pushl %eax
+        movl 0xc(%esp), %edx
         lea 0x4(%ebp), %eax
-        pushl %eax
         call prepare_ftrace_return
-        addl $8, %esp
         popl %edx
         popl %ecx
         popl %eax
diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c
index 16a571dea2ef..fe832738e1e2 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);
 }
 
 /*
@@ -120,7 +95,6 @@ unsigned long ftrace_return_to_handler(void)
  * Hook the return address and push it in the stack of return addrs
  * in current thread info.
  */
-asmlinkage
 void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr)
 {
         unsigned long old;
@@ -175,14 +149,6 @@ 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
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index 86dc353f89b9..2d6c2cf0c3bc 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -53,8 +53,14 @@ void tracing_off(void)
 /* FIXME!!! */
 u64 ring_buffer_time_stamp(int cpu)
 {
+        u64 time;
+
+        preempt_disable_notrace();
         /* shift to debug/test normalization and TIME_EXTENTS */
-        return sched_clock() << DEBUG_SHIFT;
+        time = sched_clock() << DEBUG_SHIFT;
+        preempt_enable_notrace();
+
+        return time;
 }
 
 void ring_buffer_normalize_time_stamp(int cpu, u64 *ts)
diff --git a/scripts/bootgraph.pl b/scripts/bootgraph.pl
index d2c61efc216f..a8635a10fef2 100644
--- a/scripts/bootgraph.pl
+++ b/scripts/bootgraph.pl
@@ -109,8 +109,8 @@ my $stylecounter = 0;
 my %rows;
 my $rowscount = 1;
 my @initcalls = sort { $start{$a} <=> $start{$b} } keys(%start);
-my $key;
-foreach $key (@initcalls) {
+
+foreach my $key (@initcalls) {
         my $duration = $end{$key} - $start{$key};
 
         if ($duration >= $threshold) {