ftrace: Return pt_regs to function trace callback
Return as the 4th paramater to the function tracer callback the pt_regs.
Later patches that implement regs passing for the architectures will require
having the ftrace_ops set the SAVE_REGS flag, which will tell the arch
to take the time to pass a full set of pt_regs to the ftrace_ops callback
function. If the arch does not support it then it should pass NULL.
If an arch can pass full regs, then it should define:
ARCH_SUPPORTS_FTRACE_SAVE_REGS to 1
Link: http://lkml.kernel.org/r/20120702201821.019966811@goodmis.org
Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 4cbca2e..6ff07ad 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -103,7 +103,7 @@
#if ARCH_SUPPORTS_FTRACE_OPS
static void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
- struct ftrace_ops *op);
+ struct ftrace_ops *op, struct pt_regs *regs);
#else
/* See comment below, where ftrace_ops_list_func is defined */
static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip);
@@ -121,7 +121,7 @@
*/
static void
ftrace_global_list_func(unsigned long ip, unsigned long parent_ip,
- struct ftrace_ops *op)
+ struct ftrace_ops *op, struct pt_regs *regs)
{
if (unlikely(trace_recursion_test(TRACE_GLOBAL_BIT)))
return;
@@ -129,19 +129,19 @@
trace_recursion_set(TRACE_GLOBAL_BIT);
op = rcu_dereference_raw(ftrace_global_list); /*see above*/
while (op != &ftrace_list_end) {
- op->func(ip, parent_ip, op);
+ op->func(ip, parent_ip, op, regs);
op = rcu_dereference_raw(op->next); /*see above*/
};
trace_recursion_clear(TRACE_GLOBAL_BIT);
}
static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip,
- struct ftrace_ops *op)
+ struct ftrace_ops *op, struct pt_regs *regs)
{
if (!test_tsk_trace_trace(current))
return;
- ftrace_pid_function(ip, parent_ip, op);
+ ftrace_pid_function(ip, parent_ip, op, regs);
}
static void set_ftrace_pid_function(ftrace_func_t func)
@@ -763,7 +763,7 @@
static void
function_profile_call(unsigned long ip, unsigned long parent_ip,
- struct ftrace_ops *ops)
+ struct ftrace_ops *ops, struct pt_regs *regs)
{
struct ftrace_profile_stat *stat;
struct ftrace_profile *rec;
@@ -793,7 +793,7 @@
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
static int profile_graph_entry(struct ftrace_graph_ent *trace)
{
- function_profile_call(trace->func, 0, NULL);
+ function_profile_call(trace->func, 0, NULL, NULL);
return 1;
}
@@ -2771,7 +2771,7 @@
device_initcall(ftrace_mod_cmd_init);
static void function_trace_probe_call(unsigned long ip, unsigned long parent_ip,
- struct ftrace_ops *op)
+ struct ftrace_ops *op, struct pt_regs *pt_regs)
{
struct ftrace_func_probe *entry;
struct hlist_head *hhd;
@@ -3923,7 +3923,7 @@
static void
ftrace_ops_control_func(unsigned long ip, unsigned long parent_ip,
- struct ftrace_ops *op)
+ struct ftrace_ops *op, struct pt_regs *regs)
{
if (unlikely(trace_recursion_test(TRACE_CONTROL_BIT)))
return;
@@ -3938,7 +3938,7 @@
while (op != &ftrace_list_end) {
if (!ftrace_function_local_disabled(op) &&
ftrace_ops_test(op, ip))
- op->func(ip, parent_ip, op);
+ op->func(ip, parent_ip, op, regs);
op = rcu_dereference_raw(op->next);
};
@@ -3952,7 +3952,7 @@
static inline void
__ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
- struct ftrace_ops *ignored)
+ struct ftrace_ops *ignored, struct pt_regs *regs)
{
struct ftrace_ops *op;
@@ -3971,7 +3971,7 @@
op = rcu_dereference_raw(ftrace_ops_list);
while (op != &ftrace_list_end) {
if (ftrace_ops_test(op, ip))
- op->func(ip, parent_ip, op);
+ op->func(ip, parent_ip, op, regs);
op = rcu_dereference_raw(op->next);
};
preempt_enable_notrace();
@@ -3983,17 +3983,24 @@
* the list function ignores the op parameter, we do not want any
* C side effects, where a function is called without the caller
* sending a third parameter.
+ * Archs are to support both the regs and ftrace_ops at the same time.
+ * If they support ftrace_ops, it is assumed they support regs.
+ * If call backs want to use regs, they must either check for regs
+ * being NULL, or ARCH_SUPPORTS_FTRACE_SAVE_REGS.
+ * Note, ARCH_SUPPORT_SAVE_REGS expects a full regs to be saved.
+ * An architecture can pass partial regs with ftrace_ops and still
+ * set the ARCH_SUPPORT_FTARCE_OPS.
*/
#if ARCH_SUPPORTS_FTRACE_OPS
static void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
- struct ftrace_ops *op)
+ struct ftrace_ops *op, struct pt_regs *regs)
{
- __ftrace_ops_list_func(ip, parent_ip, NULL);
+ __ftrace_ops_list_func(ip, parent_ip, NULL, regs);
}
#else
static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip)
{
- __ftrace_ops_list_func(ip, parent_ip, NULL);
+ __ftrace_ops_list_func(ip, parent_ip, NULL, NULL);
}
#endif
