1 files changed, 353 insertions, 16 deletions

diff --git a/kernel/trace/trace_functions.c b/kernel/trace/trace_functions.c
index 9236d7e25a1..c9a0b7df44f 100644
--- a/kernel/trace/trace_functions.c
+++ b/kernel/trace/trace_functions.c
@@ -9,6 +9,7 @@
  *  Copyright (C) 2004-2006 Ingo Molnar
  *  Copyright (C) 2004 William Lee Irwin III
  */
+#include <linux/ring_buffer.h>
 #include <linux/debugfs.h>
 #include <linux/uaccess.h>
 #include <linux/ftrace.h>
@@ -16,52 +17,388 @@
 
 #include "trace.h"
 
-static void start_function_trace(struct trace_array *tr)
+/* function tracing enabled */
+static int                      ftrace_function_enabled;
+
+static struct trace_array       *func_trace;
+
+static void tracing_start_function_trace(void);
+static void tracing_stop_function_trace(void);
+
+static int function_trace_init(struct trace_array *tr)
 {
+        func_trace = tr;
         tr->cpu = get_cpu();
-        tracing_reset_online_cpus(tr);
         put_cpu();
 
         tracing_start_cmdline_record();
         tracing_start_function_trace();
+        return 0;
 }
 
-static void stop_function_trace(struct trace_array *tr)
+static void function_trace_reset(struct trace_array *tr)
 {
         tracing_stop_function_trace();
         tracing_stop_cmdline_record();
 }
 
-static int function_trace_init(struct trace_array *tr)
+static void function_trace_start(struct trace_array *tr)
 {
-        start_function_trace(tr);
-        return 0;
+        tracing_reset_online_cpus(tr);
 }
 
-static void function_trace_reset(struct trace_array *tr)
+static void
+function_trace_call_preempt_only(unsigned long ip, unsigned long parent_ip)
+{
+        struct trace_array *tr = func_trace;
+        struct trace_array_cpu *data;
+        unsigned long flags;
+        long disabled;
+        int cpu, resched;
+        int pc;
+
+        if (unlikely(!ftrace_function_enabled))
+                return;
+
+        pc = preempt_count();
+        resched = ftrace_preempt_disable();
+        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);
+        ftrace_preempt_enable(resched);
+}
+
+static void
+function_trace_call(unsigned long ip, unsigned long parent_ip)
 {
-        stop_function_trace(tr);
+        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;
+
+        /*
+         * 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);
+
+        if (likely(disabled == 1)) {
+                pc = preempt_count();
+                trace_function(tr, ip, parent_ip, flags, pc);
+        }
+
+        atomic_dec(&data->disabled);
+        local_irq_restore(flags);
 }
 
-static void function_trace_start(struct trace_array *tr)
+static void
+function_stack_trace_call(unsigned long ip, unsigned long parent_ip)
 {
-        tracing_reset_online_cpus(tr);
+        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;
+
+        /*
+         * 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);
+
+        if (likely(disabled == 1)) {
+                pc = preempt_count();
+                trace_function(tr, ip, parent_ip, flags, pc);
+                /*
+                 * skip over 5 funcs:
+                 *    __ftrace_trace_stack,
+                 *    __trace_stack,
+                 *    function_stack_trace_call
+                 *    ftrace_list_func
+                 *    ftrace_call
+                 */
+                __trace_stack(tr, flags, 5, pc);
+        }
+
+        atomic_dec(&data->disabled);
+        local_irq_restore(flags);
+}
+
+
+static struct ftrace_ops trace_ops __read_mostly =
+{
+        .func = function_trace_call,
+};
+
+static struct ftrace_ops trace_stack_ops __read_mostly =
+{
+        .func = function_stack_trace_call,
+};
+
+/* Our two options */
+enum {
+        TRACE_FUNC_OPT_STACK = 0x1,
+};
+
+static struct tracer_opt func_opts[] = {
+#ifdef CONFIG_STACKTRACE
+        { TRACER_OPT(func_stack_trace, TRACE_FUNC_OPT_STACK) },
+#endif
+        { } /* Always set a last empty entry */
+};
+
+static struct tracer_flags func_flags = {
+        .val = 0, /* By default: all flags disabled */
+        .opts = func_opts
+};
+
+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
+                register_ftrace_function(&trace_ops);
+
+        ftrace_function_enabled = 1;
+}
+
+static void tracing_stop_function_trace(void)
+{
+        ftrace_function_enabled = 0;
+        /* OK if they are not registere