Merge tag 'trace-fixes-v3.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull fix for ftrace function tracer/profiler conflict from Steven Rostedt:
 "The rewrite of the ftrace code that makes it possible to allow for
  separate trampolines had a design flaw with the interaction between
  the function and function_graph tracers.

  The main flaw was the simplification of the use of multiple tracers
  having the same filter (like function and function_graph, that use the
  set_ftrace_filter file to filter their code).  The design assumed that
  the two tracers could never run simultaneously as only one tracer can
  be used at a time.  The problem with this assumption was that the
  function profiler could be implemented on top of the function graph
  tracer, and the function profiler could run at the same time as the
  function tracer.  This caused the assumption to be broken and when
  ftrace detected this failed assumpiton it would spit out a nasty
  warning and shut itself down.

  Instead of using a single ftrace_ops that switches between the
  function and function_graph callbacks, the two tracers can again use
  their own ftrace_ops.  But instead of having a complex hierarchy of
  ftrace_ops, the filter fields are placed in its own structure and the
  ftrace_ops can carefully use the same filter.  This change took a bit
  to be able to allow for this and currently only the global_ops can
  share the same filter, but this new design can easily be modified to
  allow for any ftrace_ops to share its filter with another ftrace_ops.

  The first four patches deal with the change of allowing the ftrace_ops
  to share the filter (and this needs to go to 3.16 as well).

  The fifth patch fixes a bug that was also caused by the new changes
  but only for archs other than x86, and only if those archs implement a
  direct call to the function_graph tracer which they do not do yet but
  will in the future.  It does not need to go to stable, but needs to be
  fixed before the other archs update their code to allow direct calls
  to the function_graph trampoline"

* tag 'trace-fixes-v3.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  ftrace: Use current addr when converting to nop in __ftrace_replace_code()
  ftrace: Fix function_profiler and function tracer together
  ftrace: Fix up trampoline accounting with looping on hash ops
  ftrace: Update all ftrace_ops for a ftrace_hash_ops update
  ftrace: Allow ftrace_ops to use the hashes from other ops

1 files changed, 157 insertions, 89 deletions

diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 1654b12c891..5916a8e59e8 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -65,15 +65,21 @@
 #define FL_GLOBAL_CONTROL_MASK (FTRACE_OPS_FL_CONTROL)
 
 #ifdef CONFIG_DYNAMIC_FTRACE
-#define INIT_REGEX_LOCK(opsname)	\
-	.regex_lock	= __MUTEX_INITIALIZER(opsname.regex_lock),
+#define INIT_OPS_HASH(opsname)	\
+	.func_hash		= &opsname.local_hash,			\
+	.local_hash.regex_lock	= __MUTEX_INITIALIZER(opsname.local_hash.regex_lock),
+#define ASSIGN_OPS_HASH(opsname, val) \
+	.func_hash		= val, \
+	.local_hash.regex_lock	= __MUTEX_INITIALIZER(opsname.local_hash.regex_lock),
 #else
-#define INIT_REGEX_LOCK(opsname)
+#define INIT_OPS_HASH(opsname)
+#define ASSIGN_OPS_HASH(opsname, val)
 #endif
 
 static struct ftrace_ops ftrace_list_end __read_mostly = {
 	.func		= ftrace_stub,
 	.flags		= FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_STUB,
+	INIT_OPS_HASH(ftrace_list_end)
 };
 
 /* ftrace_enabled is a method to turn ftrace on or off */
@@ -140,7 +146,8 @@ static inline void ftrace_ops_init(struct ftrace_ops *ops)
 {
 #ifdef CONFIG_DYNAMIC_FTRACE
 	if (!(ops->flags & FTRACE_OPS_FL_INITIALIZED)) {
-		mutex_init(&ops->regex_lock);
+		mutex_init(&ops->local_hash.regex_lock);
+		ops->func_hash = &ops->local_hash;
 		ops->flags |= FTRACE_OPS_FL_INITIALIZED;
 	}
 #endif
@@ -899,7 +906,7 @@ static void unregister_ftrace_profiler(void)
 static struct ftrace_ops ftrace_profile_ops __read_mostly = {
 	.func		= function_profile_call,
 	.flags		= FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_INITIALIZED,
-	INIT_REGEX_LOCK(ftrace_profile_ops)
+	INIT_OPS_HASH(ftrace_profile_ops)
 };
 
 static int register_ftrace_profiler(void)
@@ -1081,11 +1088,12 @@ static const struct ftrace_hash empty_hash = {
 #define EMPTY_HASH	((struct ftrace_hash *)&empty_hash)
 
 static struct ftrace_ops global_ops = {
-	.func			= ftrace_stub,
-	.notrace_hash		= EMPTY_HASH,
-	.filter_hash		= EMPTY_HASH,
-	.flags			= FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_INITIALIZED,
-	INIT_REGEX_LOCK(global_ops)
+	.func				= ftrace_stub,
+	.local_hash.notrace_hash	= EMPTY_HASH,
+	.local_hash.filter_hash		= EMPTY_HASH,
+	INIT_OPS_HASH(global_ops)
+	.flags				= FTRACE_OPS_FL_RECURSION_SAFE |
+					  FTRACE_OPS_FL_INITIALIZED,
 };
 
 struct ftrace_page {
@@ -1226,8 +1234,8 @@ static void free_ftrace_hash_rcu(struct ftrace_hash *hash)
 void ftrace_free_filter(struct ftrace_ops *ops)
 {
 	ftrace_ops_init(ops);
-	free_ftrace_hash(ops->filter_hash);
-	free_ftrace_hash(ops->notrace_hash);
+	free_ftrace_hash(ops->func_hash->filter_hash);
+	free_ftrace_hash(ops->func_hash->notrace_hash);
 }
 
 static struct ftrace_hash *alloc_ftrace_hash(int size_bits)
@@ -1288,9 +1296,9 @@ alloc_and_copy_ftrace_hash(int size_bits, struct ftrace_hash *hash)
 }
 
 static void
-ftrace_hash_rec_disable(struct ftrace_ops *ops, int filter_hash);
+ftrace_hash_rec_disable_modify(struct ftrace_ops *ops, int filter_hash);
 static void
-ftrace_hash_rec_enable(struct ftrace_ops *ops, int filter_hash);
+ftrace_hash_rec_enable_modify(struct ftrace_ops *ops, int filter_hash);
 
 static int
 ftrace_hash_move(struct ftrace_ops *ops, int enable,
@@ -1342,13 +1350,13 @@ update:
 	 * Remove the current set, update the hash and add
 	 * them back.
 	 */
-	ftrace_hash_rec_disable(ops, enable);
+	ftrace_hash_rec_disable_modify(ops, enable);
 
 	old_hash = *dst;
 	rcu_assign_pointer(*dst, new_hash);
 	free_ftrace_hash_rcu(old_hash);
 
-	ftrace_hash_rec_enable(ops, enable);
+	ftrace_hash_rec_enable_modify(ops, enable);
 
 	return 0;
 }
@@ -1382,8 +1390,8 @@ ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip, void *regs)
 		return 0;
 #endif
 
-	filter_hash = rcu_dereference_raw_notrace(ops->filter_hash);
-	notrace_hash = rcu_dereference_raw_notrace(ops->notrace_hash);
+	filter_hash = rcu_dereference_raw_notrace(ops->func_hash->filter_hash);
+	notrace_hash = rcu_dereference_raw_notrace(ops->func_hash->notrace_hash);
 
 	if ((ftrace_hash_empty(filter_hash) ||
 	     ftrace_lookup_ip(filter_hash, ip)) &&
@@ -1503,25 +1511,38 @@ static bool test_rec_ops_needs_regs(struct dyn_ftrace *rec)
 static void ftrace_remove_tramp(struct ftrace_ops *ops,
 				struct dyn_ftrace *rec)
 {
-	struct ftrace_func_entry *entry;
-
-	entry = ftrace_lookup_ip(ops->tramp_hash, rec->ip);
-	if (!entry)
+	/* If TRAMP is not set, no ops should have a trampoline for this */
+	if (!(rec->flags & FTRACE_FL_TRAMP))
 		return;
 
+	rec->flags &= ~FTRACE_FL_TRAMP;
+
+	if ((!ftrace_hash_empty(ops->func_hash->filter_hash) &&
+	     !ftrace_lookup_ip(ops->func_hash->filter_hash, rec->ip)) ||
+	    ftrace_lookup_ip(ops->func_hash->notrace_hash, rec->ip))
+		return;
 	/*
 	 * The tramp_hash entry will be removed at time
 	 * of update.
 	 */
 	ops->nr_trampolines--;
-	rec->flags &= ~FTRACE_FL_TRAMP;
 }
 
-static void ftrace_clear_tramps(struct dyn_ftrace *rec)
+static void ftrace_clear_tramps(struct dyn_ftrace *rec, struct ftrace_ops *ops)
 {
 	struct ftrace_ops *op;
 
+	/* If TRAMP is not set, no ops should have a trampoline for this */
+	if (!(rec->flags & FTRACE_FL_TRAMP))
+		return;
+
 	do_for_each_ftrace_op(op, ftrace_ops_list) {
+		/*
+		 * This function is called to clear other tramps
+		 * not the one that is being updated.
+		 */
+		if (op == ops)
+			continue;
 		if (op->nr_trampolines)
 			ftrace_remove_tramp(op, rec);
 	} while_for_each_ftrace_op(op);
@@ -1554,14 +1575,14 @@ static void __ftrace_hash_rec_update(struct ftrace_ops *ops,
 	 *   gets inversed.
 	 */
 	if (filter_hash) {
-		hash = ops->filter_hash;
-		other_hash = ops->notrace_hash;
+		hash = ops->func_hash->filter_hash;
+		other_hash = ops->func_hash->notrace_hash;
 		if (ftrace_hash_empty(hash))
 			all = 1;
 	} else {
 		inc = !inc;
-		hash = ops->notrace_hash;
-		other_hash = ops->filter_hash;
+		hash = ops->func_hash->notrace_hash;
+		other_hash = ops->func_hash->filter_hash;
 		/*
 		 * If the notrace hash has no items,
 		 * then there's nothing to do.
@@ -1622,13 +1643,10 @@ static void __ftrace_hash_rec_update(struct ftrace_ops *ops,
 				/*
 				 * If we are adding another function callback
 				 * to this function, and the previous had a
-				 * trampoline used, then we need to go back to
-				 * the default trampoline.
+				 * custom trampoline in use, then we need to go
+				 * back to the default trampoline.
 				 */
-				rec->flags &= ~FTRACE_FL_TRAMP;
-
-				/* remove trampolines from any ops for this rec */
-				ftrace_clear_tramps(rec);
+				ftrace_clear_tramps(rec, ops);
 			}
 
 			/*
@@ -1682,6 +1700,41 @@ static void ftrace_hash_rec_enable(struct ftrace_ops *ops,
 	__ftrace_hash_rec_update(ops, filter_hash, 1);
 }
 
+static void ftrace_hash_rec_update_modify(struct ftrace_ops *ops,
+					  int filter_hash, int inc)
+{
+	struct ftrace_ops *op;
+
+	__ftrace_hash_rec_update(ops, filter_hash, inc);
+
+	if (ops->func_hash != &global_ops.local_hash)
+		return;
+
+	/*
+	 * If the ops shares the global_ops hash, then we need to update
+	 * all ops that are enabled and use this hash.
+	 */
+	do_for_each_ftrace_op(op, ftrace_ops_list) {
+		/* Already done */
+		if (op == ops)
+			continue;
+		if (op->func_hash == &global_ops.local_hash)
+			__ftrace_hash_rec_update(op, filter_hash, inc);
+	} while_for_each_ftrace_op(op);
+}
+
+static void ftrace_hash_rec_disable_modify(struct ftrace_ops *ops,
+					   int filter_hash)
+{
+	ftrace_hash_rec_update_modify(ops, filter_hash, 0);
+}
+
+static void ftrace_hash_rec_enable_modify(struct ftrace_ops *ops,
+					  int filter_hash)
+{
+	ftrace_hash_rec_update_modify(ops, filter_hash, 1);
+}
+
 static void print_ip_ins(const char *fmt, unsigned char *p)
 {
 	int i;
@@ -1896,8 +1949,8 @@ unsigned long ftrace_get_addr_new(struct dyn_ftrace *rec)
 	if (rec->flags & FTRACE_FL_TRAMP) {
 		ops = ftrace_find_tramp_ops_new(rec);
 		if (FTRACE_WARN_ON(!ops || !ops->trampoline)) {
-			pr_warning("Bad trampoline accounting at: %p (%pS)\n",
-				    (void *)rec->ip, (void *)rec->ip);
+			pr_warn("Bad trampoline accounting at: %p (%pS) (%lx)\n",
+				(void *)rec->ip, (void *)rec->ip, rec->flags);
 			/* Ftrace is shutting down, return anything */
 			return (unsigned long)FTRACE_ADDR;
 		}
@@ -1964,7 +2017,7 @@ __ftrace_replace_code(struct dyn_ftrace *rec, int enable)
 		return ftrace_make_call(rec, ftrace_addr);
 
 	case FTRACE_UPDATE_MAKE_NOP:
-		return ftrace_make_nop(NULL, rec, ftrace_addr);
+		return ftrace_make_nop(NULL, rec, ftrace_old_addr);
 
 	case FTRACE_UPDATE_MODIFY_CALL:
 		return ftrace_modify_call(rec, ftrace_old_addr, ftrace_addr);
@@ -2227,7 +2280,10 @@ static int ftrace_save_ops_tramp_hash(struct ftrace_ops *ops)
 	} while_for_each_ftrace_rec();
 
 	/* The number of recs in the hash must match nr_trampolines */
-	FTRACE_WARN_ON(ops->tramp_hash->count != ops->nr_trampolines);
+	if (FTRACE_WARN_ON(ops->tramp_hash->count != ops->nr_trampolines))
+		pr_warn("count=%ld trampolines=%d\n",
+			ops->tramp_hash->count,
+			ops->nr_trampolines);
 
 	return 0;
 }
@@ -2436,8 +2492,8 @@ static inline int ops_traces_mod(struct ftrace_ops *ops)
 	 * Filter_hash being empty will default to trace module.
 	 * But notrace hash requires a test of individual module functions.
 	 */
-	return ftrace_hash_empty(ops->filter_hash) &&
-		ftrace_hash_empty(ops->notrace_hash);
+	return ftrace_hash_empty(ops->func_hash->filter_hash) &&
+		ftrace_hash_empty(ops->func_hash->notrace_hash);
 }
 
 /*
@@ -2459,12 +2515,12 @@ ops_references_rec(struct ftrace_ops *ops, struct dyn_ftrace *rec)
 		return 0;
 
 	/* The function must be in the filter */
-	if (!ftrace_hash_empty(ops->filter_hash) &&
-	    !ftrace_lookup_ip(ops->filter_hash, rec->ip))
+	if (!ftrace_hash_empty(ops->func_hash->filter_hash) &&
+	    !ftrace_lookup_ip(ops->func_hash->filter_hash, rec->ip))
 		return 0;
 
 	/* If in notrace hash, we ignore it too */
-	if (ftrace_lookup_ip(ops->notrace_hash, rec->ip))
+	if (ftrace_lookup_ip(ops->func_hash->notrace_hash, rec->ip))
 		return 0;
 
 	return 1;
@@ -2785,10 +2841,10 @@ t_next(struct seq_file *m, void *v, loff_t *pos)
 	} else {
 		rec = &iter->pg->records[iter->idx++];
 		if (((iter->flags & FTRACE_ITER_FILTER) &&
-		     !(ftrace_lookup_ip(ops->filter_hash, rec->ip))) ||
+		     !(ftrace_lookup_ip(ops->func_hash->filter_hash, rec->ip))) ||
 
 		    ((iter->flags & FTRACE_ITER_NOTRACE) &&
-		     !ftrace_lookup_ip(ops->notrace_hash, rec->ip)) ||
+		     !ftrace_lookup_ip(ops->func_hash->notrace_hash, rec->ip)) ||
 
 		    ((iter->flags & FTRACE_ITER_ENABLED) &&
 		     !(rec->flags & FTRACE_FL_ENABLED))) {
@@ -2837,9 +2893,9 @@ static void *t_start(struct seq_file *m, loff_t *pos)
 	 * functions are enabled.
 	 */
 	if ((iter->flags & FTRACE_ITER_FILTER &&
-	     ftrace_hash_empty(ops->filter_hash)) ||
+	     ftrace_hash_empty(ops->func_hash->filter_hash)) ||
 	    (iter->flags & FTRACE_ITER_NOTRACE &&
-	     ftrace_hash_empty(ops->notrace_hash))) {
+	     ftrace_hash_empty(ops->func_hash->notrace_hash))) {
 		if (*pos > 0)
 			return t_hash_start(m, pos);
 		iter->flags |= FTRACE_ITER_PRINTALL;
@@ -3001,12 +3057,12 @@ ftrace_regex_open(struct ftrace_ops *ops, int flag,
 	iter->ops = ops;
 	iter->flags = flag;
 
-	mutex_lock(&ops->regex_lock);
+	mutex_lock(&ops->func_hash->regex_lock);
 
 	if (flag & FTRACE_ITER_NOTRACE)
-		hash = ops->notrace_hash;
+		hash = ops->func_hash->notrace_hash;
 	else
-		hash = ops->filter_hash;
+		hash = ops->func_hash->filter_hash;
 
 	if (file->f_mode & FMODE_WRITE) {
 		const int size_bits = FTRACE_HASH_DEFAULT_BITS;
@@ -3041,7 +3097,7 @@ ftrace_regex_open(struct ftrace_ops *ops, int flag,
 		file->private_data = iter;
 
  out_unlock:
-	mutex_unlock(&ops->regex_lock);
+	mutex_unlock(&ops->func_hash->regex_lock);
 
 	return ret;
 }
@@ -3279,7 +3335,7 @@ static struct ftrace_ops trace_probe_ops __read_mostly =
 {
 	.func		= function_trace_probe_call,
 	.flags		= FTRACE_OPS_FL_INITIALIZED,
-	INIT_REGEX_LOCK(trace_probe_ops)
+	INIT_OPS_HASH(trace_probe_ops)
 };
 
 static int ftrace_probe_registered;
@@ -3342,7 +3398,7 @@ register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
 			      void *data)
 {
 	struct ftrace_func_probe *entry;
-	struct ftrace_hash **orig_hash = &trace_probe_ops.filter_hash;
+	struct ftrace_hash **orig_hash = &trace_probe_ops.func_hash->filter_hash;
 	struct ftrace_hash *hash;
 	struct ftrace_page *pg;
 	struct dyn_ftrace *rec;
@@ -3359,7 +3415,7 @@ register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
 	if (WARN_ON(not))
 		return -EINVAL;
 
-	mutex_lock(&trace_probe_ops.regex_lock);
+	mutex_lock(&trace_probe_ops.func_hash->regex_lock);
 
 	hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, *orig_hash);
 	if (!hash) {
@@ -3428,7 +3484,7 @@ register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
  out_unlock:
 	mutex_unlock(&ftrace_lock);
  out:
-	mutex_unlock(&trace_probe_ops.regex_lock);
+	mutex_unlock(&trace_probe_ops.func_hash->regex_lock);
 	free_ftrace_hash(hash);
 
 	return count;
@@ -3446,7 +3502,7 @@ __unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
 	struct ftrace_func_entry *rec_entry;
 	struct ftrace_func_probe *entry;
 	struct ftrace_func_probe *p;
-	struct ftrace_hash **orig_hash = &trace_probe_ops.filter_hash;
+	struct ftrace_hash **orig_hash = &trace_probe_ops.func_hash->filter_hash;
 	struct list_head free_list;
 	struct ftrace_hash *hash;
 	struct hlist_node *tmp;
@@ -3468,7 +3524,7 @@ __unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
 			return;
 	}
 
-	mutex_lock(&trace_probe_ops.regex_lock);
+	mutex_lock(&trace_probe_ops.func_hash->regex_lock);
 
 	hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, *orig_hash);
 	if (!hash)
@@ -3521,7 +3577,7 @@ __unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
 	mutex_unlock(&ftrace_lock);
 		
  out_unlock:
-	mutex_unlock(&trace_probe_ops.regex_lock);
+	mutex_unlock(&trace_probe_ops.func_hash->regex_lock);
 	free_ftrace_hash(hash);
 }
 
@@ -3717,12 +3773,12 @@ ftrace_set_hash(struct ftrace_ops *ops, unsigned char *buf, int len,
 	if (unlikely(ftrace_disabled))
 		return -ENODEV;
 
-	mutex_lock(&ops->regex_lock);
+	mutex_lock(&ops->func_hash->regex_lock);
 
 	if (enable)
-		orig_hash = &ops->filter_hash;
+		orig_hash = &ops->func_hash->filter_hash;
 	else
-		orig_hash = &ops->notrace_hash;
+		orig_hash = &ops->func_hash->notrace_hash;
 
 	if (reset)
 		hash = alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS);
@@ -3752,7 +3808,7 @@ ftrace_set_hash(struct ftrace_ops *ops, unsigned char *buf, int len,
 	mutex_unlock(&ftrace_lock);
 
  out_regex_unlock:
-	mutex_unlock(&ops->regex_lock);
+	mutex_unlock(&ops->func_hash->regex_lock);
 
 	free_ftrace_hash(hash);
 	return ret;
@@ -3975,15 +4031,15 @@ int ftrace_regex_release(struct inode *inode, struct file *file)
 
 	trace_parser_put(parser);
 
-	mutex_lock(&iter->ops->regex_lock);
+	mutex_lock(&iter->ops->func_hash->regex_lock);
 
 	if (file->f_mode & FMODE_WRITE) {
 		filter_hash = !!(iter->flags & FTRACE_ITER_FILTER);
 
 		if (filter_hash)
-			orig_hash = &iter->ops->filter_hash;
+			orig_hash = &iter->ops->func_hash->filter_hash;
 		else
-			orig_hash = &iter->ops->notrace_hash;
+			orig_hash = &iter->ops->func_hash->notrace_hash;
 
 		mutex_lock(&ftrace_lock);
 		ret = ftrace_hash_move(iter->ops, filter_hash,
@@ -3994,7 +4050,7 @@ int ftrace_regex_release(struct inode *inode, struct file *file)
 		mutex_unlock(&ftrace_lock);
 	}
 
-	mutex_unlock(&iter->ops->regex_lock);
+	mutex_unlock(&iter->ops->func_hash->regex_lock);
 	free_ftrace_hash(iter->hash);
 	kfree(iter);
 
@@ -4611,7 +4667,6 @@ void __init ftrace_init(void)
 static struct ftrace_ops global_ops = {
 	.func			= ftrace_stub,
 	.flags			= FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_INITIALIZED,
-	INIT_REGEX_LOCK(global_ops)
 };
 
 static int __init ftrace_nodyn_init(void)
@@ -4713,7 +4768,7 @@ ftrace_ops_control_func(unsigned long ip, unsigned long parent_ip,
 static struct ftrace_ops control_ops = {
 	.func	= ftrace_ops_control_func,
 	.flags	= FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_INITIALIZED,
-	INIT_REGEX_LOCK(control_ops)
+	INIT_OPS_HASH(control_ops)
 };
 
 static inline void
@@ -5145,6 +5200,17 @@ ftrace_enable_sysctl(struct ctl_table *table, int write,
 
 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 
+static struct ftrace_ops graph_ops = {
+	.func			= ftrace_stub,
+	.flags			= FTRACE_OPS_FL_RECURSION_SAFE |
+				   FTRACE_OPS_FL_INITIALIZED |
+				   FTRACE_OPS_FL_STUB,
+#ifdef FTRACE_GRAPH_TRAMP_ADDR
+	.trampoline		= FTRACE_GRAPH_TRAMP_ADDR,
+#endif
+	ASSIGN_OPS_HASH(graph_ops, &global_ops.local_hash)
+};
+
 static int ftrace_graph_active;
 
 int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace)
@@ -5307,12 +5373,28 @@ static int ftrace_graph_entry_test(struct ftrace_graph_ent *trace)
  */
 static void update_function_graph_func(void)
 {
-	if (ftrace_ops_list == &ftrace_list_end ||
-	    (ftrace_ops_list == &global_ops &&
-	     global_ops.next == &ftrace_list_end))
-		ftrace_graph_entry = __ftrace_graph_entry;
-	else
+	struct ftrace_ops *op;
+	bool do_test = false;
+
+	/*
+	 * The graph and global ops share the same set of functions
+	 * to test. If any other ops is on the list, then
+	 * the graph tracing needs to test if its the function
+	 * it should call.
+	 */
+	do_for_each_ftrace_op(op, ftrace_ops_list) {
+		if (op != &global_ops && op != &graph_ops &&
+		    op != &ftrace_list_end) {
+			do_test = true;
+			/* in double loop, break out with goto */
+			goto out;
+		}
+	} while_for_each_ftrace_op(op);
+ out:
+	if (do_test)
 		ftrace_graph_entry = ftrace_graph_entry_test;
+	else
+		ftrace_graph_entry = __ftrace_graph_entry;
 }
 
 static struct notifier_block ftrace_suspend_notifier = {
@@ -5353,16 +5435,7 @@ int register_ftrace_graph(trace_func_graph_ret_t retfunc,
 	ftrace_graph_entry = ftrace_graph_entry_test;
 	update_function_graph_func();
 
-	/* Function graph doesn't use the .func field of global_ops */
-	global_ops.flags |= FTRACE_OPS_FL_STUB;
-
-#ifdef CONFIG_DYNAMIC_FTRACE
-	/* Optimize function graph calling (if implemented by arch) */
-	if (FTRACE_GRAPH_TRAMP_ADDR != 0)
-		global_ops.trampoline = FTRACE_GRAPH_TRAMP_ADDR;
-#endif
-
-	ret = ftrace_startup(&global_ops, FTRACE_START_FUNC_RET);
+	ret = ftrace_startup(&graph_ops, FTRACE_START_FUNC_RET);
 
 out:
 	mutex_unlock(&ftrace_lock);
@@ -5380,12 +5453,7 @@ void unregister_ftrace_graph(void)
 	ftrace_graph_return = (trace_func_graph_ret_t)ftrace_stub;
 	ftrace_graph_entry = ftrace_graph_entry_stub;
 	__ftrace_graph_entry = ftrace_graph_entry_stub;
-	ftrace_shutdown(&global_ops, FTRACE_STOP_FUNC_RET);
-	global_ops.flags &= ~FTRACE_OPS_FL_STUB;
-#ifdef CONFIG_DYNAMIC_FTRACE
-	if (FTRACE_GRAPH_TRAMP_ADDR != 0)
-		global_ops.trampoline = 0;
-#endif
+	ftrace_shutdown(&graph_ops, FTRACE_STOP_FUNC_RET);
 	unregister_pm_notifier(&ftrace_suspend_notifier);
 	unregister_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL);