@@ -119,13 +119,45 @@ struct ftrace_ops __rcu *ftrace_ops_list __read_mostly = &ftrace_list_end;
ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub;
struct ftrace_ops global_ops;
+typedef void (*ftrace_func_no_ops_t)(unsigned long ip,
+ unsigned long parent_ip);
+
+union ftrace_func {
+ ftrace_func_t ops;
+ ftrace_func_no_ops_t no_ops;
+};
+
#if ARCH_SUPPORTS_FTRACE_OPS
static void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
struct ftrace_ops *op, struct pt_regs *regs);
+
+static inline void ftrace_set_ufunc(union ftrace_func *ufunc,
+ ftrace_func_t func)
+{
+ ufunc->ops = func;
+}
+
+static inline bool ftrace_same_address_ufunc(union ftrace_func *ufunc,
+ ftrace_func_t func)
+{
+ return (ufunc->ops == func);
+}
#else
/* See comment below, where ftrace_ops_list_func is defined */
static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip);
#define ftrace_ops_list_func ((ftrace_func_t)ftrace_ops_no_ops)
+
+static inline void ftrace_set_ufunc(union ftrace_func *ufunc,
+ ftrace_func_no_ops_t func)
+{
+ ufunc->no_ops = func;
+}
+
+static inline bool ftrace_same_address_ufunc(union ftrace_func *ufunc,
+ ftrace_func_no_ops_t func)
+{
+ return (ufunc->no_ops == func);
+}
#endif
static inline void ftrace_ops_init(struct ftrace_ops *ops)
In an effort to enable -Wcast-function-type in the top-level Makefile to support Control Flow Integrity builds, there are the need to remove all the function callback casts. ftrace_ops_list_func() can no longer be defined as ftrace_ops_no_ops(). The reason for ftrace_ops_no_ops() is to use that when an architecture calls ftrace_ops_list_func() with only two parameters (called from assembly). And to make sure there's no C side-effects, those archs call ftrace_ops_no_ops() which only has two parameters, as the function ftrace_ops_list_func() has four parameters. This patch prepares all the infrastructure to remove the casts. Define a new function pointer to use when the archs don't support ftrace ops. Also define a union to combine this new function pointer (two parameters) with the ftrace_func_t function pointer (four parameters). This way, using this union it's possible to use two different function prototypes with the same variable. Also create two static inline helpers to set and compare against the fields of the new union type. These helpers are duplicated for the archs that support ftrace ops and for the archs that don't support ftrace ops as both cases use different function prototypes. Signed-off-by: Oscar Carter <oscar.carter@gmx.com> --- kernel/trace/ftrace.c | 32 ++++++++++++++++++++++++++++++++ 1 file changed, 32 insertions(+) -- 2.20.1