tracing/function-return-tracer: set a more human readable output

[deliverable/linux.git] / arch / x86 / kernel / ftrace.c

diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c
index 924153edd97331c1b244ec63446f0978e43f5fb1..26b2d92d48b30704d4b60dd914c585e93774a8df 100644 (file)
--- a/arch/x86/kernel/ftrace.c
+++ b/arch/x86/kernel/ftrace.c
@@ -323,7 +323,7 @@ int __init ftrace_dyn_arch_init(void *data)
 }
 #endif
 
-#ifdef CONFIG_FUNCTION_RET_TRACER
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
 
 #ifndef CONFIG_DYNAMIC_FTRACE
 
@@ -347,36 +347,41 @@ void ftrace_nmi_exit(void)
 
 /* 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)
+                               unsigned long func, int *depth)
 {
        int index;
-       struct thread_info *ti = current_thread_info();
+
+       if (!current->ret_stack)
+               return -EBUSY;
 
        /* The return trace stack is full */
-       if (ti->curr_ret_stack == FTRACE_RET_STACK_SIZE - 1)
+       if (current->curr_ret_stack == FTRACE_RETFUNC_DEPTH - 1) {
+               atomic_inc(&current->trace_overrun);
                return -EBUSY;
+       }
 
-       index = ++ti->curr_ret_stack;
+       index = ++current->curr_ret_stack;
        barrier();
-       ti->ret_stack[index].ret = ret;
-       ti->ret_stack[index].func = func;
-       ti->ret_stack[index].calltime = time;
+       current->ret_stack[index].ret = ret;
+       current->ret_stack[index].func = func;
+       current->ret_stack[index].calltime = time;
+       *depth = index;
 
        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)
+static void pop_return_trace(struct ftrace_graph_ret *trace, unsigned long *ret)
 {
        int index;
 
-       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--;
+       index = current->curr_ret_stack;
+       *ret = current->ret_stack[index].ret;
+       trace->func = current->ret_stack[index].func;
+       trace->calltime = current->ret_stack[index].calltime;
+       trace->overrun = atomic_read(&current->trace_overrun);
+       trace->depth = index;
+       current->curr_ret_stack--;
 }
 
 /*
@@ -385,12 +390,14 @@ static void pop_return_trace(unsigned long *ret, unsigned long long *time,
  */
 unsigned long ftrace_return_to_handler(void)
 {
-       struct ftrace_retfunc trace;
-       pop_return_trace(&trace.ret, &trace.calltime, &trace.func);
+       struct ftrace_graph_ret trace;
+       unsigned long ret;
+
+       pop_return_trace(&trace, &ret);
        trace.rettime = cpu_clock(raw_smp_processor_id());
-       ftrace_function_return(&trace);
+       ftrace_graph_return(&trace);
 
-       return trace.ret;
+       return ret;
 }
 
 /*
@@ -402,6 +409,7 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr)
        unsigned long old;
        unsigned long long calltime;
        int faulted;
+       struct ftrace_graph_ent trace;
        unsigned long return_hooker = (unsigned long)
                                &return_to_handler;
 
@@ -435,20 +443,27 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr)
        );
 
        if (WARN_ON(faulted)) {
-               unregister_ftrace_return();
+               unregister_ftrace_graph();
                return;
        }
 
        if (WARN_ON(!__kernel_text_address(old))) {
-               unregister_ftrace_return();
+               unregister_ftrace_graph();
                *parent = old;
                return;
        }
 
        calltime = cpu_clock(raw_smp_processor_id());
 
-       if (push_return_trace(old, calltime, self_addr) == -EBUSY)
+       if (push_return_trace(old, calltime,
+                               self_addr, &trace.depth) == -EBUSY) {
                *parent = old;
+               return;
+       }
+
+       trace.func = self_addr;
+       ftrace_graph_entry(&trace);
+
 }
 
-#endif /* CONFIG_FUNCTION_RET_TRACER */
+#endif /* CONFIG_FUNCTION_GRAPH_TRACER */