Add override handler to handle kernel stack trace entry

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

1 files changed, 43 insertions, 0 deletions

diff --git a/trace-ftrace.c b/trace-ftrace.c
index 68ac7a8..b1d420d 100644
--- a/trace-ftrace.c
+++ b/trace-ftrace.c
@@ -6,6 +6,7 @@
 
 static struct event *fgraph_ret_event;
 static int fgraph_ret_id;
+static int long_size;
 
 static int get_field_val(struct trace_seq *s, void *data,
                          struct event *event, const char *name,
@@ -289,6 +290,43 @@ fgraph_ret_handler(struct trace_seq *s, void *data, int size,
         return trace_seq_putc(s, '}');
 }
 
+static int
+trace_stack_handler(struct trace_seq *s, void *data, int size,
+                    struct event *event, int cpu,
+                    unsigned long long nsecs)
+{
+        struct format_field *field;
+        unsigned long long addr;
+        const char *func;
+        int ret;
+        int i;
+
+        field = pevent_find_any_field(event, "caller");
+        if (!field) {
+                trace_seq_printf(s, "<CANT FIND FIELD %s>", "caller");
+                return -1;
+        }
+
+        ret = trace_seq_puts(s, "<stack trace>\n");
+
+        for (i = 0; i < field->size; i += long_size) {
+                addr = pevent_read_number(event->pevent,
+                                          data + field->offset + i, long_size);
+
+                if ((long_size == 8 && addr == (unsigned long long)-1) ||
+                    ((int)addr == -1))
+                        break;
+
+                func = pevent_find_function(event->pevent, addr);
+                if (func)
+                        ret = trace_seq_printf(s, "=> %s (%llx)\n", func, addr);
+                else
+                        ret = trace_seq_printf(s, "=> %llx\n", addr);
+        }
+
+        return ret;
+}
+
 int tracecmd_ftrace_overrides(struct tracecmd_input *handle)
 {
         struct pevent *pevent;
@@ -305,11 +343,16 @@ int tracecmd_ftrace_overrides(struct tracecmd_input *handle)
         pevent_register_event_handler(pevent, -1, "ftrace", "funcgraph_exit",
                                       fgraph_ret_handler);
 
+        pevent_register_event_handler(pevent, -1, "ftrace", "kernel_stack",
+                                      trace_stack_handler);
+
         /* Store the func ret id and event for later use */
         event = pevent_find_event_by_name(pevent, "ftrace", "funcgraph_exit");
         if (!event)
                 return 0;
 
+        long_size = tracecmd_long_size(handle);
+
         fgraph_ret_id = event->id;
         fgraph_ret_event = event;