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>

1 files changed, 10 insertions, 10 deletions

diff --git a/kernel/trace/trace_syscalls.c b/kernel/trace/trace_syscalls.c
index 85291c4de406..5931933587e9 100644
--- a/kernel/trace/trace_syscalls.c
+++ b/kernel/trace/trace_syscalls.c
@@ -193,8 +193,8 @@ int syscall_enter_define_fields(struct ftrace_event_call *call)
                 return ret;
 
         for (i = 0; i < meta->nb_args; i++) {
-                ret = trace_define_field(call, meta->types[i],
-                                         meta->args[i], offset,
+                ret = trace_define_field(call, (char *)meta->types[i],
+                                         (char *)meta->args[i], offset,
                                          sizeof(unsigned long), 0,
                                          FILTER_OTHER);
                 offset += sizeof(unsigned long);
@@ -277,13 +277,13 @@ void ftrace_syscall_exit(struct pt_regs *regs, long ret)
                 trace_current_buffer_unlock_commit(event, 0, 0);
 }
 
-int reg_event_syscall_enter(void *ptr)
+int reg_event_syscall_enter(struct ftrace_event_call *call)
 {
         int ret = 0;
         int num;
         char *name;
 
-        name = (char *)ptr;
+        name = (char *)call->data;
         num = syscall_name_to_nr(name);
         if (num < 0 || num >= FTRACE_SYSCALL_MAX)
                 return -ENOSYS;
@@ -301,12 +301,12 @@ int reg_event_syscall_enter(void *ptr)
         return ret;
 }
 
-void unreg_event_syscall_enter(void *ptr)
+void unreg_event_syscall_enter(struct ftrace_event_call *call)
 {
         int num;
         char *name;
 
-        name = (char *)ptr;
+        name = (char *)call->data;
         num = syscall_name_to_nr(name);
         if (num < 0 || num >= FTRACE_SYSCALL_MAX)
                 return;
@@ -318,13 +318,13 @@ void unreg_event_syscall_enter(void *ptr)
         mutex_unlock(&syscall_trace_lock);
 }
 
-int reg_event_syscall_exit(void *ptr)
+int reg_event_syscall_exit(struct ftrace_event_call *call)
 {
         int ret = 0;
         int num;
         char *name;
 
-        name = (char *)ptr;
+        name = (char *)call->data;
         num = syscall_name_to_nr(name);
         if (num < 0 || num >= FTRACE_SYSCALL_MAX)
                 return -ENOSYS;
@@ -342,12 +342,12 @@ int reg_event_syscall_exit(void *ptr)
         return ret;
 }
 
-void unreg_event_syscall_exit(void *ptr)
+void unreg_event_syscall_exit(struct ftrace_event_call *call)
 {
         int num;
         char *name;
 
-        name = (char *)ptr;
+        name = (char *)call->data;
         num = syscall_name_to_nr(name);
         if (num < 0 || num >= FTRACE_SYSCALL_MAX)
                 return;