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authorSteven Rostedt <srostedt@redhat.com>2011-05-03 22:49:52 -0400
committerSteven Rostedt <rostedt@goodmis.org>2011-05-18 15:29:49 -0400
commit2b499381bc50ede01b3d8eab164ca2fad00655f0 (patch)
tree3140c277582b03b1645fffcb829763d62e2f01fa /kernel/trace/ftrace.c
parentbd69c30b1d08032d97ab0dabd7a1eb7fb73ca2b2 (diff)
ftrace: Have global_ops store the functions that are to be traced
This is a step towards each ops structure defining its own set of functions to trace. As the current code with pid's and such are specific to the global_ops, it is restructured to be used with the global ops. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Diffstat (limited to 'kernel/trace/ftrace.c')
-rw-r--r--kernel/trace/ftrace.c69
1 files changed, 53 insertions, 16 deletions
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 8fef1d99bbb..dcce0bf9c84 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -91,6 +91,7 @@ static struct ftrace_ops *ftrace_list __read_mostly = &ftrace_list_end;
ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub;
ftrace_func_t __ftrace_trace_function __read_mostly = ftrace_stub;
ftrace_func_t ftrace_pid_function __read_mostly = ftrace_stub;
+static struct ftrace_ops global_ops;
/*
* Traverse the ftrace_list, invoking all entries. The reason that we
@@ -153,7 +154,7 @@ static void ftrace_test_stop_func(unsigned long ip, unsigned long parent_ip)
}
#endif
-static void update_ftrace_function(void)
+static void update_global_ops(void)
{
ftrace_func_t func;
@@ -173,6 +174,18 @@ static void update_ftrace_function(void)
set_ftrace_pid_function(func);
func = ftrace_pid_func;
}
+
+ global_ops.func = func;
+}
+
+static void update_ftrace_function(void)
+{
+ ftrace_func_t func;
+
+ update_global_ops();
+
+ func = global_ops.func;
+
#ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST
ftrace_trace_function = func;
#else
@@ -181,24 +194,19 @@ static void update_ftrace_function(void)
#endif
}
-static int __register_ftrace_function(struct ftrace_ops *ops)
+static void add_ftrace_ops(struct ftrace_ops **list, struct ftrace_ops *ops)
{
- ops->next = ftrace_list;
+ ops->next = *list;
/*
* We are entering ops into the ftrace_list but another
* CPU might be walking that list. We need to make sure
* the ops->next pointer is valid before another CPU sees
* the ops pointer included into the ftrace_list.
*/
- rcu_assign_pointer(ftrace_list, ops);
-
- if (ftrace_enabled)
- update_ftrace_function();
-
- return 0;
+ rcu_assign_pointer(*list, ops);
}
-static int __unregister_ftrace_function(struct ftrace_ops *ops)
+static int remove_ftrace_ops(struct ftrace_ops **list, struct ftrace_ops *ops)
{
struct ftrace_ops **p;
@@ -206,13 +214,12 @@ static int __unregister_ftrace_function(struct ftrace_ops *ops)
* If we are removing the last function, then simply point
* to the ftrace_stub.
*/
- if (ftrace_list == ops && ops->next == &ftrace_list_end) {
- ftrace_trace_function = ftrace_stub;
- ftrace_list = &ftrace_list_end;
+ if (*list == ops && ops->next == &ftrace_list_end) {
+ *list = &ftrace_list_end;
return 0;
}
- for (p = &ftrace_list; *p != &ftrace_list_end; p = &(*p)->next)
+ for (p = list; *p != &ftrace_list_end; p = &(*p)->next)
if (*p == ops)
break;
@@ -220,7 +227,37 @@ static int __unregister_ftrace_function(struct ftrace_ops *ops)
return -1;
*p = (*p)->next;
+ return 0;
+}
+
+static int __register_ftrace_function(struct ftrace_ops *ops)
+{
+ if (ftrace_disabled)
+ return -ENODEV;
+
+ if (FTRACE_WARN_ON(ops == &global_ops))
+ return -EINVAL;
+
+ add_ftrace_ops(&ftrace_list, ops);
+ if (ftrace_enabled)
+ update_ftrace_function();
+
+ return 0;
+}
+static int __unregister_ftrace_function(struct ftrace_ops *ops)
+{
+ int ret;
+
+ if (ftrace_disabled)
+ return -ENODEV;
+
+ if (FTRACE_WARN_ON(ops == &global_ops))
+ return -EINVAL;
+
+ ret = remove_ftrace_ops(&ftrace_list, ops);
+ if (ret < 0)
+ return ret;
if (ftrace_enabled)
update_ftrace_function();
@@ -894,7 +931,7 @@ enum {
FTRACE_OPS_FL_ENABLED = 1,
};
-struct ftrace_ops global_ops = {
+static struct ftrace_ops global_ops = {
.func = ftrace_stub,
.notrace_hash = EMPTY_HASH,
.filter_hash = EMPTY_HASH,
@@ -3263,7 +3300,7 @@ void __init ftrace_init(void)
#else
-struct ftrace_ops global_ops = {
+static struct ftrace_ops global_ops = {
.func = ftrace_stub,
};