aboutsummaryrefslogtreecommitdiffstats
path: root/kernel/trace/trace_functions_graph.c
diff options
context:
space:
mode:
Diffstat (limited to 'kernel/trace/trace_functions_graph.c')
-rw-r--r--kernel/trace/trace_functions_graph.c53
1 files changed, 42 insertions, 11 deletions
diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c
index 169b3c44ee97..086af4f5c3e8 100644
--- a/kernel/trace/trace_functions_graph.c
+++ b/kernel/trace/trace_functions_graph.c
@@ -118,8 +118,8 @@ print_graph_duration(struct trace_array *tr, unsigned long long duration,
struct trace_seq *s, u32 flags);
/* Add a function return address to the trace stack on thread info.*/
-int
-ftrace_push_return_trace(unsigned long ret, unsigned long func, int *depth,
+static int
+ftrace_push_return_trace(unsigned long ret, unsigned long func,
unsigned long frame_pointer, unsigned long *retp)
{
unsigned long long calltime;
@@ -177,9 +177,31 @@ ftrace_push_return_trace(unsigned long ret, unsigned long func, int *depth,
#ifdef HAVE_FUNCTION_GRAPH_RET_ADDR_PTR
current->ret_stack[index].retp = retp;
#endif
- *depth = current->curr_ret_stack;
+ return 0;
+}
+
+int function_graph_enter(unsigned long ret, unsigned long func,
+ unsigned long frame_pointer, unsigned long *retp)
+{
+ struct ftrace_graph_ent trace;
+
+ trace.func = func;
+ trace.depth = ++current->curr_ret_depth;
+
+ if (ftrace_push_return_trace(ret, func,
+ frame_pointer, retp))
+ goto out;
+
+ /* Only trace if the calling function expects to */
+ if (!ftrace_graph_entry(&trace))
+ goto out_ret;
return 0;
+ out_ret:
+ current->curr_ret_stack--;
+ out:
+ current->curr_ret_depth--;
+ return -EBUSY;
}
/* Retrieve a function return address to the trace stack on thread info.*/
@@ -241,7 +263,13 @@ ftrace_pop_return_trace(struct ftrace_graph_ret *trace, unsigned long *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;
+ trace->depth = current->curr_ret_depth--;
+ /*
+ * We still want to trace interrupts coming in if
+ * max_depth is set to 1. Make sure the decrement is
+ * seen before ftrace_graph_return.
+ */
+ barrier();
}
/*
@@ -255,6 +283,12 @@ unsigned long ftrace_return_to_handler(unsigned long frame_pointer)
ftrace_pop_return_trace(&trace, &ret, frame_pointer);
trace.rettime = trace_clock_local();
+ ftrace_graph_return(&trace);
+ /*
+ * The ftrace_graph_return() may still access the current
+ * ret_stack structure, we need to make sure the update of
+ * curr_ret_stack is after that.
+ */
barrier();
current->curr_ret_stack--;
/*
@@ -267,13 +301,6 @@ unsigned long ftrace_return_to_handler(unsigned long frame_pointer)
return ret;
}
- /*
- * The trace should run after decrementing the ret counter
- * in case an interrupt were to come in. We don't want to
- * lose the interrupt if max_depth is set.
- */
- ftrace_graph_return(&trace);
-
if (unlikely(!ret)) {
ftrace_graph_stop();
WARN_ON(1);
@@ -482,6 +509,8 @@ void trace_graph_return(struct ftrace_graph_ret *trace)
int cpu;
int pc;
+ ftrace_graph_addr_finish(trace);
+
local_irq_save(flags);
cpu = raw_smp_processor_id();
data = per_cpu_ptr(tr->trace_buffer.data, cpu);
@@ -505,6 +534,8 @@ void set_graph_array(struct trace_array *tr)
static void trace_graph_thresh_return(struct ftrace_graph_ret *trace)
{
+ ftrace_graph_addr_finish(trace);
+
if (tracing_thresh &&
(trace->rettime - trace->calltime < tracing_thresh))
return;