ftrace,bpf: Use single direct ops for bpf trampolines

arch/x86/Kconfig

@@ -335,6 +335,7 @@ config X86
 	select SCHED_SMT			if SMP
 	select ARCH_SUPPORTS_SCHED_CLUSTER	if SMP
 	select ARCH_SUPPORTS_SCHED_MC		if SMP
+	select HAVE_SINGLE_FTRACE_DIRECT_OPS	if X86_64 && DYNAMIC_FTRACE_WITH_DIRECT_CALLS
 
 config INSTRUCTION_DECODER
 	def_bool y

include/linux/bpf.h

@@ -1307,14 +1307,17 @@ struct bpf_tramp_image {
 };
 
 struct bpf_trampoline {
-	/* hlist for trampoline_table */
-	struct hlist_node hlist;
+	/* hlist for trampoline_key_table */
+	struct hlist_node hlist_key;
+	/* hlist for trampoline_ip_table */
+	struct hlist_node hlist_ip;
 	struct ftrace_ops *fops;
 	/* serializes access to fields of this trampoline */
 	struct mutex mutex;
 	refcount_t refcnt;
 	u32 flags;
 	u64 key;
+	unsigned long ip;
 	struct {
 		struct btf_func_model model;
 		void *addr;

include/linux/ftrace.h

@@ -359,7 +359,6 @@ enum {
 	FTRACE_OPS_FL_DIRECT			= BIT(17),
 	FTRACE_OPS_FL_SUBOP			= BIT(18),
 	FTRACE_OPS_FL_GRAPH			= BIT(19),
-	FTRACE_OPS_FL_JMP			= BIT(20),
 };
 
 #ifndef CONFIG_DYNAMIC_FTRACE_WITH_ARGS
@@ -403,9 +402,25 @@ enum ftrace_ops_cmd {
  *        Negative on failure. The return value is dependent on the
  *        callback.
  */
-typedef int (*ftrace_ops_func_t)(struct ftrace_ops *op, enum ftrace_ops_cmd cmd);
+typedef int (*ftrace_ops_func_t)(struct ftrace_ops *op, unsigned long ip, enum ftrace_ops_cmd cmd);
 
 #ifdef CONFIG_DYNAMIC_FTRACE
+
+#define FTRACE_HASH_DEFAULT_BITS 10
+
+struct ftrace_hash {
+	unsigned long		size_bits;
+	struct hlist_head	*buckets;
+	unsigned long		count;
+	unsigned long		flags;
+	struct rcu_head		rcu;
+};
+
+struct ftrace_hash *alloc_ftrace_hash(int size_bits);
+void free_ftrace_hash(struct ftrace_hash *hash);
+struct ftrace_func_entry *add_hash_entry_direct(struct ftrace_hash *hash,
+						unsigned long ip, unsigned long direct);
+
 /* The hash used to know what functions callbacks trace */
 struct ftrace_ops_hash {
 	struct ftrace_hash __rcu	*notrace_hash;
@@ -535,6 +550,10 @@ int unregister_ftrace_direct(struct ftrace_ops *ops, unsigned long addr,
 int modify_ftrace_direct(struct ftrace_ops *ops, unsigned long addr);
 int modify_ftrace_direct_nolock(struct ftrace_ops *ops, unsigned long addr);
 
+int update_ftrace_direct_add(struct ftrace_ops *ops, struct ftrace_hash *hash);
+int update_ftrace_direct_del(struct ftrace_ops *ops, struct ftrace_hash *hash);
+int update_ftrace_direct_mod(struct ftrace_ops *ops, struct ftrace_hash *hash, bool do_direct_lock);
+
 void ftrace_stub_direct_tramp(void);
 
 #else
@@ -561,6 +580,21 @@ static inline int modify_ftrace_direct_nolock(struct ftrace_ops *ops, unsigned l
 	return -ENODEV;
 }
 
+static inline int update_ftrace_direct_add(struct ftrace_ops *ops, struct ftrace_hash *hash)
+{
+	return -ENODEV;
+}
+
+static inline int update_ftrace_direct_del(struct ftrace_ops *ops, struct ftrace_hash *hash)
+{
+	return -ENODEV;
+}
+
+static inline int update_ftrace_direct_mod(struct ftrace_ops *ops, struct ftrace_hash *hash, bool do_direct_lock)
+{
+	return -ENODEV;
+}
+
 /*
  * This must be implemented by the architecture.
  * It is the way the ftrace direct_ops helper, when called