1 files changed, 168 insertions, 45 deletions

diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c
index 8b592418d8b..b3749a2c313 100644
--- a/kernel/trace/trace_functions_graph.c
+++ b/kernel/trace/trace_functions_graph.c
@@ -52,12 +52,13 @@ static struct tracer_flags tracer_flags = {
         .opts = trace_opts
 };
 
-/* pid on the last trace processed */
+static struct trace_array *graph_array;
 
 
 /* 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)
+ftrace_push_return_trace(unsigned long ret, unsigned long func, int *depth,
+                         unsigned long frame_pointer)
 {
         unsigned long long calltime;
         int index;
@@ -85,6 +86,7 @@ ftrace_push_return_trace(unsigned long ret, unsigned long func, int *depth)
         current->ret_stack[index].func = func;
         current->ret_stack[index].calltime = calltime;
         current->ret_stack[index].subtime = 0;
+        current->ret_stack[index].fp = frame_pointer;
         *depth = index;
 
         return 0;
@@ -92,7 +94,8 @@ ftrace_push_return_trace(unsigned long ret, unsigned long func, int *depth)
 
 /* Retrieve a function return address to the trace stack on thread info.*/
 static void
-ftrace_pop_return_trace(struct ftrace_graph_ret *trace, unsigned long *ret)
+ftrace_pop_return_trace(struct ftrace_graph_ret *trace, unsigned long *ret,
+                        unsigned long frame_pointer)
 {
         int index;
 
@@ -106,6 +109,31 @@ ftrace_pop_return_trace(struct ftrace_graph_ret *trace, unsigned long *ret)
                 return;
         }
 
+#ifdef CONFIG_HAVE_FUNCTION_GRAPH_FP_TEST
+        /*
+         * The arch may choose to record the frame pointer used
+         * and check it here to make sure that it is what we expect it
+         * to be. If gcc does not set the place holder of the return
+         * address in the frame pointer, and does a copy instead, then
+         * the function graph trace will fail. This test detects this
+         * case.
+         *
+         * Currently, x86_32 with optimize for size (-Os) makes the latest
+         * gcc do the above.
+         */
+        if (unlikely(current->ret_stack[index].fp != frame_pointer)) {
+                ftrace_graph_stop();
+                WARN(1, "Bad frame pointer: expected %lx, received %lx\n"
+                     "  from func %pF return to %lx\n",
+                     current->ret_stack[index].fp,
+                     frame_pointer,
+                     (void *)current->ret_stack[index].func,
+                     current->ret_stack[index].ret);
+                *ret = (unsigned long)panic;
+                return;
+        }
+#endif
+
         *ret = current->ret_stack[index].ret;
         trace->func = current->ret_stack[index].func;
         trace->calltime = current->ret_stack[index].calltime;
@@ -117,12 +145,12 @@ ftrace_pop_return_trace(struct ftrace_graph_ret *trace, unsigned long *ret)
  * Send the trace to the ring-buffer.
  * @return the original return address.
  */
-unsigned long ftrace_return_to_handler(void)
+unsigned long ftrace_return_to_handler(unsigned long frame_pointer)
 {
         struct ftrace_graph_ret trace;
         unsigned long ret;
 
-        ftrace_pop_return_trace(&trace, &ret);
+        ftrace_pop_return_trace(&trace, &ret, frame_pointer);
         trace.rettime = trace_clock_local();
         ftrace_graph_return(&trace);
         barrier();
@@ -138,10 +166,123 @@ unsigned long ftrace_return_to_handler(void)
         return ret;
 }
 
+static int __trace_graph_entry(struct trace_array *tr,
+                                struct ftrace_graph_ent *trace,
+                                unsigned long flags,
+                                int pc)
+{
+        struct ftrace_event_call *call = &event_funcgraph_entry;
+        struct ring_buffer_event *event;
+        struct ring_buffer *buffer = tr->buffer;
+        struct ftrace_graph_ent_entry *entry;
+
+        if (unlikely(local_read(&__get_cpu_var(ftrace_cpu_disabled))))
+                return 0;
+
+        event = trace_buffer_lock_reserve(buffer, TRACE_GRAPH_ENT,
+                                          sizeof(*entry), flags, pc);
+        if (!event)
+                return 0;
+        entry   = ring_buffer_event_data(event);
+        entry->graph_ent                        = *trace;
+        if (!filter_current_check_discard(buffer, call, entry, event))
+                ring_buffer_unlock_commit(buffer, event);
+
+        return 1;
+}
+
+int trace_graph_entry(struct ftrace_graph_ent *trace)
+{
+        struct trace_array *tr = graph_array;
+        struct trace_array_cpu *data;
+        unsigned long flags;
+        long disabled;
+        int ret;
+        int cpu;
+        int pc;
+
+        if (unlikely(!tr))
+                return 0;
+
+        if (!ftrace_trace_task(current))
+                return 0;
+
+        if (!ftrace_graph_addr(trace->func))
+                return 0;
+
+        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();
+                ret = __trace_graph_entry(tr, trace, flags, pc);
+        } else {
+                ret = 0;
+        }
+        /* Only do the atomic if it is not already set */
+        if (!test_tsk_trace_graph(current))
+                set_tsk_trace_graph(current);
+
+        atomic_dec(&data->disabled);
+        local_irq_restore(flags);
+
+        return ret;
+}
+
+static void __trace_graph_return(struct trace_array *tr,
+                                struct ftrace_graph_ret *trace,
+                                unsigned long flags,
+                                int pc)
+{
+        struct ftrace_event_call *call = &event_funcgraph_exit;
+        struct ring_buffer_event *event;
+        struct ring_buffer *buffer = tr->buffer;
+        struct ftrace_graph_ret_entry *entry;
+
+        if (unlikely(local_read(&__get_cpu_var(ftrace_cpu_disabled))))
+                return;
+
+        event = trace_buffer_lock_reserve(buffer, TRACE_GRAPH_RET,
+                                          sizeof(*entry), flags, pc);
+        if (!event)
+                return;
+        entry   = ring_buffer_event_data(event);
+        entry->ret                              = *trace;
+        if (!filter_current_check_discard(buffer, call, entry, event))
+                ring_buffer_unlock_commit(buffer, event);
+}
+
+void trace_graph_return(struct ftrace_graph_ret *trace)
+{
+        struct trace_array *tr = graph_array;
+        struct trace_array_cpu *data;
+        unsigned long flags;
+        long disabled;
+        int cpu;
+        int pc;
+
+        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_graph_return(tr, trace, flags, pc);