tracing: Ftrace dynamic ftrace_event_call support

Add dynamic ftrace_event_call support to ftrace. Trace engines can add
new ftrace_event_call to ftrace on the fly. Each operator function of
the call takes an ftrace_event_call data structure as an argument,
because these functions may be shared among several ftrace_event_calls.

Changes from v13:
 - Define remove_subsystem_dir() always (revirt a2ca5e03), because
   trace_remove_event_call() uses it.
 - Modify syscall tracer because of ftrace_event_call change.

[fweisbec@gmail.com: Fixed conflict against latest tracing/core]

Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Avi Kivity <avi@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Frank Ch. Eigler <fche@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Jason Baron <jbaron@redhat.com>
Cc: Jim Keniston <jkenisto@us.ibm.com>
Cc: K.Prasad <prasad@linux.vnet.ibm.com>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Przemysław Pawełczyk <przemyslaw@pawelczyk.it>
Cc: Roland McGrath <roland@redhat.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Tom Zanussi <tzanussi@gmail.com>
Cc: Vegard Nossum <vegard.nossum@gmail.com>
LKML-Reference: <20090813203453.31965.71901.stgit@localhost.localdomain>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>

2 files changed, 12 insertions, 11 deletions

diff --git a/include/linux/ftrace_event.h b/include/linux/ftrace_event.h
index ace2da9e0a0d..1ab3089b5c59 100644
--- a/include/linux/ftrace_event.h
+++ b/include/linux/ftrace_event.h
@@ -112,12 +112,12 @@ struct ftrace_event_call {
         struct dentry           *dir;
         struct trace_event      *event;
         int                     enabled;
-        int                     (*regfunc)(void *);
-        void                    (*unregfunc)(void *);
+        int                     (*regfunc)(struct ftrace_event_call *);
+        void                    (*unregfunc)(struct ftrace_event_call *);
         int                     id;
-        int                     (*raw_init)(void);
-        int                     (*show_format)(struct ftrace_event_call *call,
-                                               struct trace_seq *s);
+        int                     (*raw_init)(struct ftrace_event_call *);
+        int                     (*show_format)(struct ftrace_event_call *,
+                                               struct trace_seq *);
         int                     (*define_fields)(struct ftrace_event_call *);
         struct list_head        fields;
         int                     filter_active;
@@ -147,11 +147,12 @@ enum {
         FILTER_PTR_STRING,
 };
 
-extern int trace_define_field(struct ftrace_event_call *call,
-                              const char *type, const char *name,
-                              int offset, int size, int is_signed,
-                              int filter_type);
 extern int trace_define_common_fields(struct ftrace_event_call *call);
+extern int trace_define_field(struct ftrace_event_call *call, char *type,
+                              char *name, int offset, int size, int is_signed,
+                              int filter_type);
+extern int trace_add_event_call(struct ftrace_event_call *call);
+extern void trace_remove_event_call(struct ftrace_event_call *call);
 
 #define is_signed_type(type)    (((type)(-1)) < 0)
 
diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
index f124c8995555..646102eeff92 100644
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h
@@ -165,7 +165,7 @@ static void prof_sysexit_disable_##sname(struct ftrace_event_call *event_call) \
         struct trace_event enter_syscall_print_##sname = {              \
                 .trace                  = print_syscall_enter,          \
         };                                                              \
-        static int init_enter_##sname(void)                             \
+        static int init_enter_##sname(struct ftrace_event_call *call)   \
         {                                                               \
                 int num, id;                                            \
                 num = syscall_name_to_nr("sys"#sname);                  \
@@ -202,7 +202,7 @@ static void prof_sysexit_disable_##sname(struct ftrace_event_call *event_call) \
         struct trace_event exit_syscall_print_##sname = {               \
                 .trace                  = print_syscall_exit,           \
         };                                                              \
-        static int init_exit_##sname(void)                              \
+        static int init_exit_##sname(struct ftrace_event_call *call)    \
         {                                                               \
                 int num, id;                                            \
                 num = syscall_name_to_nr("sys"#sname);                  \