ftrace/x86: Show trampoline call function in enabled_functions
The file /sys/kernel/debug/tracing/eneabled_functions is used to debug
ftrace function hooks. Add to the output what function is being called
by the trampoline if the arch supports it.
Add support for this feature in x86_64.
Cc: H. Peter Anvin <hpa@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Tested-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 15f85ea..422e1f8 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -2952,6 +2952,22 @@
mutex_unlock(&ftrace_lock);
}
+void * __weak
+arch_ftrace_trampoline_func(struct ftrace_ops *ops, struct dyn_ftrace *rec)
+{
+ return NULL;
+}
+
+static void add_trampoline_func(struct seq_file *m, struct ftrace_ops *ops,
+ struct dyn_ftrace *rec)
+{
+ void *ptr;
+
+ ptr = arch_ftrace_trampoline_func(ops, rec);
+ if (ptr)
+ seq_printf(m, " ->%pS", ptr);
+}
+
static int t_show(struct seq_file *m, void *v)
{
struct ftrace_iterator *iter = m->private;
@@ -2975,19 +2991,21 @@
seq_printf(m, "%ps", (void *)rec->ip);
if (iter->flags & FTRACE_ITER_ENABLED) {
+ struct ftrace_ops *ops = NULL;
+
seq_printf(m, " (%ld)%s",
ftrace_rec_count(rec),
rec->flags & FTRACE_FL_REGS ? " R" : " ");
if (rec->flags & FTRACE_FL_TRAMP_EN) {
- struct ftrace_ops *ops;
-
ops = ftrace_find_tramp_ops_any(rec);
if (ops)
seq_printf(m, "\ttramp: %pS",
(void *)ops->trampoline);
else
seq_printf(m, "\ttramp: ERROR!");
+
}
+ add_trampoline_func(m, ops, rec);
}
seq_printf(m, "\n");
