1 files changed, 14 insertions, 47 deletions

diff --git a/kernel/trace/trace_functions.c b/kernel/trace/trace_functions.c
index 8e3ad8082ab7..1c327ef13a9a 100644
--- a/kernel/trace/trace_functions.c
+++ b/kernel/trace/trace_functions.c
@@ -47,34 +47,6 @@ static void function_trace_start(struct trace_array *tr)
         tracing_reset_online_cpus(tr);
 }
 
-static void
-function_trace_call_preempt_only(unsigned long ip, unsigned long parent_ip,
-                                 struct ftrace_ops *op, struct pt_regs *pt_regs)
-{
-        struct trace_array *tr = func_trace;
-        struct trace_array_cpu *data;
-        unsigned long flags;
-        long disabled;
-        int cpu;
-        int pc;
-
-        if (unlikely(!ftrace_function_enabled))
-                return;
-
-        pc = preempt_count();
-        preempt_disable_notrace();
-        local_save_flags(flags);
-        cpu = raw_smp_processor_id();
-        data = tr->data[cpu];
-        disabled = atomic_inc_return(&data->disabled);
-
-        if (likely(disabled == 1))
-                trace_function(tr, ip, parent_ip, flags, pc);
-
-        atomic_dec(&data->disabled);
-        preempt_enable_notrace();
-}
-
 /* Our option */
 enum {
         TRACE_FUNC_OPT_STACK    = 0x1,
@@ -85,34 +57,34 @@ static struct tracer_flags func_flags;
 static void
 function_trace_call(unsigned long ip, unsigned long parent_ip,
                     struct ftrace_ops *op, struct pt_regs *pt_regs)
-
 {
         struct trace_array *tr = func_trace;
         struct trace_array_cpu *data;
         unsigned long flags;
-        long disabled;
+        unsigned int bit;
         int cpu;
         int pc;
 
         if (unlikely(!ftrace_function_enabled))
                 return;
 
-        /*
-         * Need to use raw, since this must be called before the
-         * recursive protection is performed.
-         */
-        local_irq_save(flags);
-        cpu = raw_smp_processor_id();
-        data = tr->data[cpu];
-        disabled = atomic_inc_return(&data->disabled);
+        pc = preempt_count();
+        preempt_disable_notrace();
 
-        if (likely(disabled == 1)) {
-                pc = preempt_count();
+        bit = trace_test_and_set_recursion(TRACE_FTRACE_START, TRACE_FTRACE_MAX);
+        if (bit < 0)
+                goto out;
+
+        cpu = smp_processor_id();
+        data = tr->data[cpu];
+        if (!atomic_read(&data->disabled)) {
+                local_save_flags(flags);
                 trace_function(tr, ip, parent_ip, flags, pc);
         }
+        trace_clear_recursion(bit);
 
-        atomic_dec(&data->disabled);
-        local_irq_restore(flags);
+ out:
+        preempt_enable_notrace();
 }
 
 static void
@@ -185,11 +157,6 @@ static void tracing_start_function_trace(void)
 {
         ftrace_function_enabled = 0;
 
-        if (trace_flags & TRACE_ITER_PREEMPTONLY)
-                trace_ops.func = function_trace_call_preempt_only;
-        else
-                trace_ops.func = function_trace_call;
-
         if (func_flags.val & TRACE_FUNC_OPT_STACK)
                 register_ftrace_function(&trace_stack_ops);
         else