tracing: Separate out trace events from global variables

The trace events for ftrace are all defined via global variables.
The arrays of events and event systems are linked to a global list.
This prevents multiple users of the event system (what to enable and
what not to).

By adding descriptors to represent the event/file relation, as well
as to which trace_array descriptor they are associated with, allows
for more than one set of events to be defined. Once the trace events
files have a link between the trace event and the trace_array they
are associated with, we can create multiple trace_arrays that can
record separate events in separate buffers.

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

2 files changed, 42 insertions, 12 deletions

diff --git a/include/linux/ftrace_event.h b/include/linux/ftrace_event.h
index 13a54d0bdfa8..c7191d482f98 100644
--- a/include/linux/ftrace_event.h
+++ b/include/linux/ftrace_event.h
@@ -182,18 +182,20 @@ extern int ftrace_event_reg(struct ftrace_event_call *event,
                             enum trace_reg type, void *data);
 
 enum {
-        TRACE_EVENT_FL_ENABLED_BIT,
         TRACE_EVENT_FL_FILTERED_BIT,
-        TRACE_EVENT_FL_RECORDED_CMD_BIT,
         TRACE_EVENT_FL_CAP_ANY_BIT,
         TRACE_EVENT_FL_NO_SET_FILTER_BIT,
         TRACE_EVENT_FL_IGNORE_ENABLE_BIT,
 };
 
+/*
+ * Event flags:
+ *  FILTERED      - The event has a filter attached
+ *  CAP_ANY       - Any user can enable for perf
+ *  NO_SET_FILTER - Set when filter has error and is to be ignored
+ */
 enum {
-        TRACE_EVENT_FL_ENABLED          = (1 << TRACE_EVENT_FL_ENABLED_BIT),
         TRACE_EVENT_FL_FILTERED         = (1 << TRACE_EVENT_FL_FILTERED_BIT),
-        TRACE_EVENT_FL_RECORDED_CMD     = (1 << TRACE_EVENT_FL_RECORDED_CMD_BIT),
         TRACE_EVENT_FL_CAP_ANY          = (1 << TRACE_EVENT_FL_CAP_ANY_BIT),
         TRACE_EVENT_FL_NO_SET_FILTER    = (1 << TRACE_EVENT_FL_NO_SET_FILTER_BIT),
         TRACE_EVENT_FL_IGNORE_ENABLE    = (1 << TRACE_EVENT_FL_IGNORE_ENABLE_BIT),
@@ -203,12 +205,44 @@ struct ftrace_event_call {
         struct list_head        list;
         struct ftrace_event_class *class;
         char                    *name;
-        struct dentry           *dir;
         struct trace_event      event;
         const char              *print_fmt;
         struct event_filter     *filter;
+        struct list_head        *files;
         void                    *mod;
         void                    *data;
+        int                     flags; /* static flags of different events */
+
+#ifdef CONFIG_PERF_EVENTS
+        int                             perf_refcount;
+        struct hlist_head __percpu      *perf_events;
+#endif
+};
+
+struct trace_array;
+struct ftrace_subsystem_dir;
+
+enum {
+        FTRACE_EVENT_FL_ENABLED_BIT,
+        FTRACE_EVENT_FL_RECORDED_CMD_BIT,
+};
+
+/*
+ * Ftrace event file flags:
+ *  ENABELD       - The event is enabled
+ *  RECORDED_CMD  - The comms should be recorded at sched_switch
+ */
+enum {
+        FTRACE_EVENT_FL_ENABLED         = (1 << FTRACE_EVENT_FL_ENABLED_BIT),
+        FTRACE_EVENT_FL_RECORDED_CMD    = (1 << FTRACE_EVENT_FL_RECORDED_CMD_BIT),
+};
+
+struct ftrace_event_file {
+        struct list_head                list;
+        struct ftrace_event_call        *event_call;
+        struct dentry                   *dir;
+        struct trace_array              *tr;
+        struct ftrace_subsystem_dir     *system;
 
         /*
          * 32 bit flags:
@@ -223,17 +257,12 @@ struct ftrace_event_call {
          *
          * Note: Reads of flags do not hold the event_mutex since
          * they occur in critical sections. But the way flags
-         * is currently used, these changes do no affect the code
+         * is currently used, these changes do not affect the code
          * except that when a change is made, it may have a slight
          * delay in propagating the changes to other CPUs due to
          * caching and such.
          */
         unsigned int            flags;
-
-#ifdef CONFIG_PERF_EVENTS
-        int                             perf_refcount;
-        struct hlist_head __percpu      *perf_events;
-#endif
 };
 
 #define __TRACE_EVENT_FLAGS(name, value)                                \
diff --git a/include/trace/ftrace.h b/include/trace/ftrace.h
index 40dc5e8fe340..191d9661e277 100644
--- a/include/trace/ftrace.h
+++ b/include/trace/ftrace.h
@@ -518,7 +518,8 @@ static inline notrace int ftrace_get_offsets_##call(			\
 static notrace void                                                     \
 ftrace_raw_event_##call(void *__data, proto)                            \
 {                                                                       \
-        struct ftrace_event_call *event_call = __data;                  \
+        struct ftrace_event_file *ftrace_file = __data;                 \
+        struct ftrace_event_call *event_call = ftrace_file->event_call; \
         struct ftrace_data_offsets_##call __maybe_unused __data_offsets;\
         struct ring_buffer_event *event;                                \
         struct ftrace_raw_##call *entry;                                \