Create default event override for function tracer

The libparsevent currently does special cases for the function tracer.
This patch replaces the special case with a event override. This is
loaded by libtracecmd.

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

6 files changed, 56 insertions, 9 deletions

diff --git a/Makefile b/Makefile
index 38407ec..1f9e2e5 100644
--- a/Makefile
+++ b/Makefile
@@ -35,7 +35,7 @@ libparsevent.so: $(PEVENT_LIB_OBJS)
 libparsevent.a: $(PEVENT_LIB_OBJS)
         $(RM) $@;  $(AR) rcs $@ $^
 
-TCMD_LIB_OBJS = $(PEVENT_LIB_OBJS) trace-util.o trace-input.o
+TCMD_LIB_OBJS = $(PEVENT_LIB_OBJS) trace-util.o trace-input.o trace-ftrace.o
 
 libtracecmd.a: $(TCMD_LIB_OBJS)
         $(RM) $@;  $(AR) rcs $@ $^
diff --git a/parse-events.c b/parse-events.c
index 82d5d21..7fdd64b 100644
--- a/parse-events.c
+++ b/parse-events.c
@@ -2694,9 +2694,6 @@ static void pretty_print(struct trace_seq *s, void *data, int size, struct event
                 return;
         }
 
-        if (event->flags & EVENT_FL_ISFUNC)
-                ptr = " %pF <-- %pF";
-
         if (event->flags & EVENT_FL_ISBPRINT) {
                 bprint_fmt = get_bprint_format(data, size, event);
                 args = make_bprint_args(bprint_fmt, data, size, event);
@@ -3467,10 +3464,7 @@ int pevent_parse_event(char *buf, unsigned long size, char *sys)
 
                 event->flags |= EVENT_FL_ISFTRACE;
 
-                if (strcmp(event->name, "function") == 0)
-                        event->flags |= EVENT_FL_ISFUNC;
-
-                else if (strcmp(event->name, "funcgraph_entry") == 0)
+                if (strcmp(event->name, "funcgraph_entry") == 0)
                         event->flags |= EVENT_FL_ISFUNCENT;
 
                 else if (strcmp(event->name, "funcgraph_exit") == 0)
diff --git a/parse-events.h b/parse-events.h
index 6adf526..138f140 100644
--- a/parse-events.h
+++ b/parse-events.h
@@ -189,7 +189,6 @@ enum {
         EVENT_FL_ISFTRACE       = 0x01,
         EVENT_FL_ISPRINT        = 0x02,
         EVENT_FL_ISBPRINT       = 0x04,
-        EVENT_FL_ISFUNC         = 0x08,
         EVENT_FL_ISFUNCENT      = 0x10,
         EVENT_FL_ISFUNCRET      = 0x20,
 
diff --git a/trace-cmd.h b/trace-cmd.h
index e9e3b1e..34e4012 100644
--- a/trace-cmd.h
+++ b/trace-cmd.h
@@ -42,5 +42,7 @@ tracecmd_peek_data(struct tracecmd_handle *handle, int cpu);
 struct record *
 tracecmd_read_data(struct tracecmd_handle *handle, int cpu);
 
+int tracecmd_ftrace_overrides(void);
+
 
 #endif /* _TRACE_CMD_H */
diff --git a/trace-ftrace.c b/trace-ftrace.c
new file mode 100644
index 0000000..3174f89
--- /dev/null
+++ b/trace-ftrace.c
@@ -0,0 +1,50 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "parse-events.h"
+
+static int function_handler(struct trace_seq *s, void *data, int size,
+                            struct event *event)
+{
+        struct format_field *ip = pevent_find_field(event, "ip");
+        struct format_field *pip = pevent_find_field(event, "parent_ip");
+        unsigned long long function;
+        const char *func;
+
+        if (!ip)
+                return trace_seq_printf(s, "CANT FIND FIELD IP");
+
+        if (pevent_read_number_field(ip, data, &function))
+                trace_seq_printf(s, " function=INVALID");
+        else {
+                func = pevent_find_function(function);
+                if (func)
+                        trace_seq_printf(s, "%s <-- ", func);
+                else
+                        trace_seq_printf(s, "0x%llx", function);
+        }
+
+        if (!pip)
+                return trace_seq_printf(s, "CANT FIND FIELD PARENT_IP");
+
+        if (pevent_read_number_field(pip, data, &function))
+                trace_seq_printf(s, " function=INVALID");
+        else {
+                func = pevent_find_function(function);
+                if (func)
+                        trace_seq_printf(s, "%s", func);
+                else
+                        trace_seq_printf(s, "0x%llx", function);
+        }
+
+        return 0;
+}
+
+int tracecmd_ftrace_overrides(void)
+{
+        pevent_register_event_handler(-1, "ftrace", "function",
+                                      function_handler);
+
+        return 0;
+}
diff --git a/trace-input.c b/trace-input.c
index 239c9d3..77db2f5 100644
--- a/trace-input.c
+++ b/trace-input.c
@@ -399,6 +399,8 @@ int tracecmd_read_headers(struct tracecmd_handle *handle)
         if (ret < 0)
                 return -1;
 
+        /* register default ftrace functions first */
+        tracecmd_ftrace_overrides();
 
         trace_load_plugins();