tracing: Allow events to share their print functions

Multiple events may use the same method to print their data.
Instead of having all events have a pointer to their print funtions,
the trace_event structure now points to a trace_event_functions structure
that will hold the way to print ouf the event.

The event itself is now passed to the print function to let the print
function know what kind of event it should print.

This opens the door to consolidating the way several events print
their output.

   text	   data	    bss	    dec	    hex	filename
4913961	1088356	 861512	6863829	 68bbd5	vmlinux.orig
4900382	1048964	 861512	6810858	 67ecea	vmlinux.init
4900446	1049028	 861512	6810986	 67ed6a	vmlinux.preprint

This change slightly increases the size but is needed for the next change.

v3: Fix the branch tracer events to handle this change.

v2: Fix the new function graph tracer event calls to handle this change.

Acked-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Acked-by: Masami Hiramatsu <mhiramat@redhat.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

1 files changed, 92 insertions, 45 deletions

diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c
index 2404c129a8c9..fc9d4dbb089e 100644
--- a/kernel/trace/trace_output.c
+++ b/kernel/trace/trace_output.c
@@ -726,6 +726,9 @@ int register_ftrace_event(struct trace_event *event)
         if (WARN_ON(!event))
                 goto out;
 
+        if (WARN_ON(!event->funcs))
+                goto out;
+
         INIT_LIST_HEAD(&event->list);
 
         if (!event->type) {
@@ -758,14 +761,14 @@ int register_ftrace_event(struct trace_event *event)
                         goto out;
         }
 
-        if (event->trace == NULL)
-                event->trace = trace_nop_print;
-        if (event->raw == NULL)
-                event->raw = trace_nop_print;
-        if (event->hex == NULL)
-                event->hex = trace_nop_print;
-        if (event->binary == NULL)
-                event->binary = trace_nop_print;
+        if (event->funcs->trace == NULL)
+                event->funcs->trace = trace_nop_print;
+        if (event->funcs->raw == NULL)
+                event->funcs->raw = trace_nop_print;
+        if (event->funcs->hex == NULL)
+                event->funcs->hex = trace_nop_print;
+        if (event->funcs->binary == NULL)
+                event->funcs->binary = trace_nop_print;
 
         key = event->type & (EVENT_HASHSIZE - 1);
 
@@ -807,13 +810,15 @@ EXPORT_SYMBOL_GPL(unregister_ftrace_event);
  * Standard events
  */
 
-enum print_line_t trace_nop_print(struct trace_iterator *iter, int flags)
+enum print_line_t trace_nop_print(struct trace_iterator *iter, int flags,
+                                  struct trace_event *event)
 {
         return TRACE_TYPE_HANDLED;
 }
 
 /* TRACE_FN */
-static enum print_line_t trace_fn_trace(struct trace_iterator *iter, int flags)
+static enum print_line_t trace_fn_trace(struct trace_iterator *iter, int flags,
+                                        struct trace_event *event)
 {
         struct ftrace_entry *field;
         struct trace_seq *s = &iter->seq;
@@ -840,7 +845,8 @@ static enum print_line_t trace_fn_trace(struct trace_iterator *iter, int flags)
         return TRACE_TYPE_PARTIAL_LINE;
 }
 
-static enum print_line_t trace_fn_raw(struct trace_iterator *iter, int flags)
+static enum print_line_t trace_fn_raw(struct trace_iterator *iter, int flags,
+                                      struct trace_event *event)
 {
         struct ftrace_entry *field;
 
@@ -854,7 +860,8 @@ static enum print_line_t trace_fn_raw(struct trace_iterator *iter, int flags)
         return TRACE_TYPE_HANDLED;
 }
 
-static enum print_line_t trace_fn_hex(struct trace_iterator *iter, int flags)
+static enum print_line_t trace_fn_hex(struct trace_iterator *iter, int flags,
+                                      struct trace_event *event)
 {
         struct ftrace_entry *field;
         struct trace_seq *s = &iter->seq;
@@ -867,7 +874,8 @@ static enum print_line_t trace_fn_hex(struct trace_iterator *iter, int flags)
         return TRACE_TYPE_HANDLED;
 }
 
-static enum print_line_t trace_fn_bin(struct trace_iterator *iter, int flags)
+static enum print_line_t trace_fn_bin(struct trace_iterator *iter, int flags,
+                                      struct trace_event *event)
 {
         struct ftrace_entry *field;
         struct trace_seq *s = &iter->seq;
@@ -880,14 +888,18 @@ static enum print_line_t trace_fn_bin(struct trace_iterator *iter, int flags)
         return TRACE_TYPE_HANDLED;
 }
 
-static struct trace_event trace_fn_event = {
-        .type           = TRACE_FN,
+static struct trace_event_functions trace_fn_funcs = {
         .trace          = trace_fn_trace,
         .raw            = trace_fn_raw,
         .hex            = trace_fn_hex,
         .binary         = trace_fn_bin,
 };
 
+static struct trace_event trace_fn_event = {
+        .type           = TRACE_FN,
+        .funcs          = &trace_fn_funcs,
+};
+
 /* TRACE_CTX an TRACE_WAKE */
 static enum print_line_t trace_ctxwake_print(struct trace_iterator *iter,
                                              char *delim)
@@ -916,13 +928,14 @@ static enum print_line_t trace_ctxwake_print(struct trace_iterator *iter,
         return TRACE_TYPE_HANDLED;
 }
 
-static enum print_line_t trace_ctx_print(struct trace_iterator *iter, int flags)
+static enum print_line_t trace_ctx_print(struct trace_iterator *iter, int flags,
+                                         struct trace_event *event)
 {
         return trace_ctxwake_print(iter, "==>");
 }
 
 static enum print_line_t trace_wake_print(struct trace_iterator *iter,
-                                          int flags)
+                                          int flags, struct trace_event *event)
 {
         return trace_ctxwake_print(iter, "  +");
 }
@@ -950,12 +963,14 @@ static int trace_ctxwake_raw(struct trace_iterator *iter, char S)
         return TRACE_TYPE_HANDLED;
 }
 
-static enum print_line_t trace_ctx_raw(struct trace_iterator *iter, int flags)
+static enum print_line_t trace_ctx_raw(struct trace_iterator *iter, int flags,
+                                       struct trace_event *event)
 {
         return trace_ctxwake_raw(iter, 0);
 }
 
-static enum print_line_t trace_wake_raw(struct trace_iterator *iter, int flags)
+static enum print_line_t trace_wake_raw(struct trace_iterator *iter, int flags,
+                                        struct trace_event *event)
 {
         return trace_ctxwake_raw(iter, '+');
 }
@@ -984,18 +999,20 @@ static int trace_ctxwake_hex(struct trace_iterator *iter, char S)
         return TRACE_TYPE_HANDLED;
 }
 
-static enum print_line_t trace_ctx_hex(struct trace_iterator *iter, int flags)
+static enum print_line_t trace_ctx_hex(struct trace_iterator *iter, int flags,
+                                       struct trace_event *event)
 {
         return trace_ctxwake_hex(iter, 0);
 }
 
-static enum print_line_t trace_wake_hex(struct trace_iterator *iter, int flags)
+static enum print_line_t trace_wake_hex(struct trace_iterator *iter, int flags,
+                                        struct trace_event *event)
 {
         return trace_ctxwake_hex(iter, '+');
 }
 
 static enum print_line_t trace_ctxwake_bin(struct trace_iterator *iter,
-                                           int flags)
+                                           int flags, struct trace_event *event)
 {
         struct ctx_switch_entry *field;
         struct trace_seq *s = &iter->seq;
@@ -1012,25 +1029,33 @@ static enum print_line_t trace_ctxwake_bin(struct trace_iterator *iter,
         return TRACE_TYPE_HANDLED;
 }
 
-static struct trace_event trace_ctx_event = {
-        .type           = TRACE_CTX,
+static struct trace_event_functions trace_ctx_funcs = {
         .trace          = trace_ctx_print,
         .raw            = trace_ctx_raw,
         .hex            = trace_ctx_hex,
         .binary         = trace_ctxwake_bin,
 };
 
-static struct trace_event trace_wake_event = {
-        .type           = TRACE_WAKE,
+static struct trace_event trace_ctx_event = {
+        .type           = TRACE_CTX,
+        .funcs          = &trace_ctx_funcs,
+};
+
+static struct trace_event_functions trace_wake_funcs = {
         .trace          = trace_wake_print,
         .raw            = trace_wake_raw,
         .hex            = trace_wake_hex,
         .binary         = trace_ctxwake_bin,
 };
 
+static struct trace_event trace_wake_event = {
+        .type           = TRACE_WAKE,
+        .funcs          = &trace_wake_funcs,
+};
+
 /* TRACE_SPECIAL */
 static enum print_line_t trace_special_print(struct trace_iterator *iter,
-                                             int flags)
+                                             int flags, struct trace_event *event)
 {
         struct special_entry *field;
 
@@ -1046,7 +1071,7 @@ static enum print_line_t trace_special_print(struct trace_iterator *iter,
 }
 
 static enum print_line_t trace_special_hex(struct trace_iterator *iter,
-                                           int flags)
+                                           int flags, struct trace_event *event)
 {
         struct special_entry *field;
         struct trace_seq *s = &iter->seq;
@@ -1061,7 +1086,7 @@ static enum print_line_t trace_special_hex(struct trace_iterator *iter,
 }
 
 static enum print_line_t trace_special_bin(struct trace_iterator *iter,
-                                           int flags)
+                                           int flags, struct trace_event *event)
 {
         struct special_entry *field;
         struct trace_seq *s = &iter->seq;
@@ -1075,18 +1100,22 @@ static enum print_line_t trace_special_bin(struct trace_iterator *iter,
         return TRACE_TYPE_HANDLED;
 }
 
-static struct trace_event trace_special_event = {
-        .type           = TRACE_SPECIAL,
+static struct trace_event_functions trace_special_funcs = {
         .trace          = trace_special_print,
         .raw            = trace_special_print,
         .hex            = trace_special_hex,
         .binary         = trace_special_bin,
 };
 
+static struct trace_event trace_special_event = {
+        .type           = TRACE_SPECIAL,
+        .funcs          = &trace_special_funcs,
+};
+
 /* TRACE_STACK */
 
 static enum print_line_t trace_stack_print(struct trace_iterator *iter,
-                                           int flags)
+                                           int flags, struct trace_event *event)
 {
         struct stack_entry *field;
         struct trace_seq *s = &iter->seq;
@@ -1114,17 +1143,21 @@ static enum print_line_t trace_stack_print(struct trace_iterator *iter,
         return TRACE_TYPE_PARTIAL_LINE;
 }
 
-static struct trace_event trace_stack_event = {
-        .type           = TRACE_STACK,
+static struct trace_event_functions trace_stack_funcs = {
         .trace          = trace_stack_print,
         .raw            = trace_special_print,
         .hex            = trace_special_hex,
         .binary         = trace_special_bin,
 };
 
+static struct trace_event trace_stack_event = {
+        .type           = TRACE_STACK,
+        .funcs          = &trace_stack_funcs,
+};
+
 /* TRACE_USER_STACK */
 static enum print_line_t trace_user_stack_print(struct trace_iterator *iter,
-                                                int flags)
+                                                int flags, struct trace_event *event)
 {
         struct userstack_entry *field;
         struct trace_seq *s = &iter->seq;
@@ -1143,17 +1176,22 @@ static enum print_line_t trace_user_stack_print(struct trace_iterator *iter,
         return TRACE_TYPE_PARTIAL_LINE;
 }
 
-static struct trace_event trace_user_stack_event = {
-        .type           = TRACE_USER_STACK,
+static struct trace_event_functions trace_user_stack_funcs = {
         .trace          = trace_user_stack_print,
         .raw            = trace_special_print,
         .hex            = trace_special_hex,
         .binary         = trace_special_bin,
 };
 
+static struct trace_event trace_user_stack_event = {
+        .type           = TRACE_USER_STACK,
+        .funcs          = &trace_user_stack_funcs,
+};
+
 /* TRACE_BPRINT */
 static enum print_line_t
-trace_bprint_print(struct trace_iterator *iter, int flags)
+trace_bprint_print(struct trace_iterator *iter, int flags,
+                   struct trace_event *event)
 {
         struct trace_entry *entry = iter->ent;
         struct trace_seq *s = &iter->seq;
@@ -1178,7 +1216,8 @@ trace_bprint_print(struct trace_iterator *iter, int flags)
 
 
 static enum print_line_t
-trace_bprint_raw(struct trace_iterator *iter, int flags)
+trace_bprint_raw(struct trace_iterator *iter, int flags,
+                 struct trace_event *event)
 {
         struct bprint_entry *field;
         struct trace_seq *s = &iter->seq;
@@ -1197,16 +1236,19 @@ trace_bprint_raw(struct trace_iterator *iter, int flags)
         return TRACE_TYPE_PARTIAL_LINE;
 }
 
+static struct trace_event_functions trace_bprint_funcs = {
+        .trace          = trace_bprint_print,
+        .raw            = trace_bprint_raw,
+};
 
 static struct trace_event trace_bprint_event = {
         .type           = TRACE_BPRINT,
-        .trace          = trace_bprint_print,
-        .raw            = trace_bprint_raw,
+        .funcs          = &trace_bprint_funcs,
 };
 
 /* TRACE_PRINT */
 static enum print_line_t trace_print_print(struct trace_iterator *iter,
-                                           int flags)
+                                           int flags, struct trace_event *event)
 {
         struct print_entry *field;
         struct trace_seq *s = &iter->seq;
@@ -1225,7 +1267,8 @@ static enum print_line_t trace_print_print(struct trace_iterator *iter,
         return TRACE_TYPE_PARTIAL_LINE;
 }
 
-static enum print_line_t trace_print_raw(struct trace_iterator *iter, int flags)
+static enum print_line_t trace_print_raw(struct trace_iterator *iter, int flags,
+                                         struct trace_event *event)
 {
         struct print_entry *field;
 
@@ -1240,12 +1283,16 @@ static enum print_line_t trace_print_raw(struct trace_iterator *iter, int flags)
         return TRACE_TYPE_PARTIAL_LINE;
 }
 
-static struct trace_event trace_print_event = {
-        .type           = TRACE_PRINT,
+static struct trace_event_functions trace_print_funcs = {
         .trace          = trace_print_print,
         .raw            = trace_print_raw,
 };
 
+static struct trace_event trace_print_event = {
+        .type           = TRACE_PRINT,
+        .funcs          = &trace_print_funcs,
+};
+
 
 static struct trace_event *events[] __initdata = {
         &trace_fn_event,