Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index e23eb9f..f296d89 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -18,8 +18,8 @@
 #include <linux/clocksource.h>
 #include <linux/sched/task.h>
 #include <linux/kallsyms.h>
+#include <linux/security.h>
 #include <linux/seq_file.h>
-#include <linux/suspend.h>
 #include <linux/tracefs.h>
 #include <linux/hardirq.h>
 #include <linux/kthread.h>
@@ -34,12 +34,14 @@
 #include <linux/list.h>
 #include <linux/hash.h>
 #include <linux/rcupdate.h>
+#include <linux/kprobes.h>
 
 #include <trace/events/sched.h>
 
 #include <asm/sections.h>
 #include <asm/setup.h>
 
+#include "ftrace_internal.h"
 #include "trace_output.h"
 #include "trace_stat.h"
 
@@ -69,15 +71,16 @@
 #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_OPS_HASH(opsname)
-#define ASSIGN_OPS_HASH(opsname, val)
 #endif
 
-static struct ftrace_ops ftrace_list_end __read_mostly = {
+enum {
+	FTRACE_MODIFY_ENABLE_FL		= (1 << 0),
+	FTRACE_MODIFY_MAY_SLEEP_FL	= (1 << 1),
+};
+
+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)
@@ -112,11 +115,11 @@
  */
 static int ftrace_disabled __read_mostly;
 
-static DEFINE_MUTEX(ftrace_lock);
+DEFINE_MUTEX(ftrace_lock);
 
-static struct ftrace_ops __rcu *ftrace_ops_list __read_mostly = &ftrace_list_end;
+struct ftrace_ops __rcu *ftrace_ops_list __read_mostly = &ftrace_list_end;
 ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub;
-static struct ftrace_ops global_ops;
+struct ftrace_ops global_ops;
 
 #if ARCH_SUPPORTS_FTRACE_OPS
 static void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
@@ -127,26 +130,6 @@
 #define ftrace_ops_list_func ((ftrace_func_t)ftrace_ops_no_ops)
 #endif
 
-/*
- * Traverse the ftrace_global_list, invoking all entries.  The reason that we
- * can use rcu_dereference_raw_notrace() is that elements removed from this list
- * are simply leaked, so there is no need to interact with a grace-period
- * mechanism.  The rcu_dereference_raw_notrace() calls are needed to handle
- * concurrent insertions into the ftrace_global_list.
- *
- * Silly Alpha and silly pointer-speculation compiler optimizations!
- */
-#define do_for_each_ftrace_op(op, list)			\
-	op = rcu_dereference_raw_notrace(list);			\
-	do
-
-/*
- * Optimized for just a single item in the list (as that is the normal case).
- */
-#define while_for_each_ftrace_op(op)				\
-	while (likely(op = rcu_dereference_raw_notrace((op)->next)) &&	\
-	       unlikely((op) != &ftrace_list_end))
-
 static inline void ftrace_ops_init(struct ftrace_ops *ops)
 {
 #ifdef CONFIG_DYNAMIC_FTRACE
@@ -173,7 +156,7 @@
 {
 	/*
 	 * This function is just a stub to implement a hard force
-	 * of synchronize_sched(). This requires synchronizing
+	 * of synchronize_rcu(). This requires synchronizing
 	 * tasks even in userspace and idle.
 	 *
 	 * Yes, function tracing is rude.
@@ -186,18 +169,6 @@
 	smp_rmb();
 }
 
-#ifdef CONFIG_FUNCTION_GRAPH_TRACER
-static void update_function_graph_func(void);
-
-/* Both enabled by default (can be cleared by function_graph tracer flags */
-static bool fgraph_sleep_time = true;
-static bool fgraph_graph_time = true;
-
-#else
-static inline void update_function_graph_func(void) { }
-#endif
-
-
 static ftrace_func_t ftrace_ops_get_list_func(struct ftrace_ops *ops)
 {
 	/*
@@ -334,7 +305,7 @@
 
 static void ftrace_update_trampoline(struct ftrace_ops *ops);
 
-static int __register_ftrace_function(struct ftrace_ops *ops)
+int __register_ftrace_function(struct ftrace_ops *ops)
 {
 	if (ops->flags & FTRACE_OPS_FL_DELETED)
 		return -EINVAL;
@@ -375,7 +346,7 @@
 	return 0;
 }
 
-static int __unregister_ftrace_function(struct ftrace_ops *ops)
+int __unregister_ftrace_function(struct ftrace_ops *ops)
 {
 	int ret;
 
@@ -815,9 +786,16 @@
 }
 
 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
+static bool fgraph_graph_time = true;
+
+void ftrace_graph_graph_time_control(bool enable)
+{
+	fgraph_graph_time = enable;
+}
+
 static int profile_graph_entry(struct ftrace_graph_ent *trace)
 {
-	int index = current->curr_ret_stack;
+	struct ftrace_ret_stack *ret_stack;
 
 	function_profile_call(trace->func, 0, NULL, NULL);
 
@@ -825,14 +803,16 @@
 	if (!current->ret_stack)
 		return 0;
 
-	if (index >= 0 && index < FTRACE_RETFUNC_DEPTH)
-		current->ret_stack[index].subtime = 0;
+	ret_stack = ftrace_graph_get_ret_stack(current, 0);
+	if (ret_stack)
+		ret_stack->subtime = 0;
 
 	return 1;
 }
 
 static void profile_graph_return(struct ftrace_graph_ret *trace)
 {
+	struct ftrace_ret_stack *ret_stack;
 	struct ftrace_profile_stat *stat;
 	unsigned long long calltime;
 	struct ftrace_profile *rec;
@@ -850,16 +830,15 @@
 	calltime = trace->rettime - trace->calltime;
 
 	if (!fgraph_graph_time) {
-		int index;
-
-		index = current->curr_ret_stack;
 
 		/* Append this call time to the parent time to subtract */
-		if (index)
-			current->ret_stack[index - 1].subtime += calltime;
+		ret_stack = ftrace_graph_get_ret_stack(current, 1);
+		if (ret_stack)
+			ret_stack->subtime += calltime;
 
-		if (current->ret_stack[index].subtime < calltime)
-			calltime -= current->ret_stack[index].subtime;
+		ret_stack = ftrace_graph_get_ret_stack(current, 0);
+		if (ret_stack && ret_stack->subtime < calltime)
+			calltime -= ret_stack->subtime;
 		else
 			calltime = 0;
 	}
@@ -874,15 +853,19 @@
 	local_irq_restore(flags);
 }
 
+static struct fgraph_ops fprofiler_ops = {
+	.entryfunc = &profile_graph_entry,
+	.retfunc = &profile_graph_return,
+};
+
 static int register_ftrace_profiler(void)
 {
-	return register_ftrace_graph(&profile_graph_return,
-				     &profile_graph_entry);
+	return register_ftrace_graph(&fprofiler_ops);
 }
 
 static void unregister_ftrace_profiler(void)
 {
-	unregister_ftrace_graph();
+	unregister_ftrace_graph(&fprofiler_ops);
 }
 #else
 static struct ftrace_ops ftrace_profile_ops __read_mostly = {
@@ -934,7 +917,7 @@
 			ftrace_profile_enabled = 0;
 			/*
 			 * unregister_ftrace_profiler calls stop_machine
-			 * so this acts like an synchronize_sched.
+			 * so this acts like an synchronize_rcu.
 			 */
 			unregister_ftrace_profiler();
 		}
@@ -1021,12 +1004,6 @@
 }
 #endif /* CONFIG_FUNCTION_PROFILER */
 
-#ifdef CONFIG_FUNCTION_GRAPH_TRACER
-static int ftrace_graph_active;
-#else
-# define ftrace_graph_active 0
-#endif
-
 #ifdef CONFIG_DYNAMIC_FTRACE
 
 static struct ftrace_ops *removed_ops;
@@ -1067,7 +1044,7 @@
 };
 #define EMPTY_HASH	((struct ftrace_hash *)&empty_hash)
 
-static struct ftrace_ops global_ops = {
+struct ftrace_ops global_ops = {
 	.func				= ftrace_stub,
 	.local_hash.notrace_hash	= EMPTY_HASH,
 	.local_hash.filter_hash		= EMPTY_HASH,
@@ -1086,7 +1063,7 @@
 
 	/*
 	 * Some of the ops may be dynamically allocated,
-	 * they are freed after a synchronize_sched().
+	 * they are freed after a synchronize_rcu().
 	 */
 	preempt_disable_notrace();
 
@@ -1286,7 +1263,7 @@
 {
 	if (!hash || hash == EMPTY_HASH)
 		return;
-	call_rcu_sched(&hash->rcu, __free_ftrace_hash_rcu);
+	call_rcu(&hash->rcu, __free_ftrace_hash_rcu);
 }
 
 void ftrace_free_filter(struct ftrace_ops *ops)
@@ -1501,9 +1478,9 @@
  * the ip is not in the ops->notrace_hash.
  *
  * This needs to be called with preemption disabled as
- * the hashes are freed with call_rcu_sched().
+ * the hashes are freed with call_rcu().
  */
-static int
+int
 ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip, void *regs)
 {
 	struct ftrace_ops_hash hash;
@@ -1646,6 +1623,11 @@
 	return  keep_regs;
 }
 
+static struct ftrace_ops *
+ftrace_find_tramp_ops_any(struct dyn_ftrace *rec);
+static struct ftrace_ops *
+ftrace_find_tramp_ops_next(struct dyn_ftrace *rec, struct ftrace_ops *ops);
+
 static bool __ftrace_hash_rec_update(struct ftrace_ops *ops,
 				     int filter_hash,
 				     bool inc)
@@ -1774,15 +1756,17 @@
 			}
 
 			/*
-			 * If the rec had TRAMP enabled, then it needs to
-			 * be cleared. As TRAMP can only be enabled iff
-			 * there is only a single ops attached to it.
-			 * In otherwords, always disable it on decrementing.
-			 * In the future, we may set it if rec count is
-			 * decremented to one, and the ops that is left
-			 * has a trampoline.
+			 * The TRAMP needs to be set only if rec count
+			 * is decremented to one, and the ops that is
+			 * left has a trampoline. As TRAMP can only be
+			 * enabled if there is only a single ops attached
+			 * to it.
 			 */
-			rec->flags &= ~FTRACE_FL_TRAMP;
+			if (ftrace_rec_count(rec) == 1 &&
+			    ftrace_find_tramp_ops_any(rec))
+				rec->flags |= FTRACE_FL_TRAMP;
+			else
+				rec->flags &= ~FTRACE_FL_TRAMP;
 
 			/*
 			 * flags will be cleared in ftrace_check_record()
@@ -1792,7 +1776,7 @@
 		count++;
 
 		/* Must match FTRACE_UPDATE_CALLS in ftrace_modify_all_code() */
-		update |= ftrace_test_record(rec, 1) != FTRACE_UPDATE_IGNORE;
+		update |= ftrace_test_record(rec, true) != FTRACE_UPDATE_IGNORE;
 
 		/* Shortcut, if we handled all records, we are done. */
 		if (!all && count == hash->count)
@@ -1975,11 +1959,6 @@
 		printk(KERN_CONT "%s%02x", i ? ":" : "", p[i]);
 }
 
-static struct ftrace_ops *
-ftrace_find_tramp_ops_any(struct dyn_ftrace *rec);
-static struct ftrace_ops *
-ftrace_find_tramp_ops_next(struct dyn_ftrace *rec, struct ftrace_ops *ops);
-
 enum ftrace_bug_type ftrace_bug_type;
 const void *ftrace_expected;
 
@@ -2013,7 +1992,7 @@
  * modifying the code. @failed should be one of either:
  * EFAULT - if the problem happens on reading the @ip address
  * EINVAL - if what is read at @ip is not what was expected
- * EPERM - if the problem happens on writting to the @ip address
+ * EPERM - if the problem happens on writing to the @ip address
  */
 void ftrace_bug(int failed, struct dyn_ftrace *rec)
 {
@@ -2071,7 +2050,7 @@
 	}
 }
 
-static int ftrace_check_record(struct dyn_ftrace *rec, int enable, int update)
+static int ftrace_check_record(struct dyn_ftrace *rec, bool enable, bool update)
 {
 	unsigned long flag = 0UL;
 
@@ -2170,28 +2149,28 @@
 /**
  * ftrace_update_record, set a record that now is tracing or not
  * @rec: the record to update
- * @enable: set to 1 if the record is tracing, zero to force disable
+ * @enable: set to true if the record is tracing, false to force disable
  *
  * The records that represent all functions that can be traced need
  * to be updated when tracing has been enabled.
  */
-int ftrace_update_record(struct dyn_ftrace *rec, int enable)
+int ftrace_update_record(struct dyn_ftrace *rec, bool enable)
 {
-	return ftrace_check_record(rec, enable, 1);
+	return ftrace_check_record(rec, enable, true);
 }
 
 /**
  * ftrace_test_record, check if the record has been enabled or not
  * @rec: the record to test
- * @enable: set to 1 to check if enabled, 0 if it is disabled
+ * @enable: set to true to check if enabled, false if it is disabled
  *
  * The arch code may need to test if a record is already set to
  * tracing to determine how to modify the function code that it
  * represents.
  */
-int ftrace_test_record(struct dyn_ftrace *rec, int enable)
+int ftrace_test_record(struct dyn_ftrace *rec, bool enable)
 {
-	return ftrace_check_record(rec, enable, 0);
+	return ftrace_check_record(rec, enable, false);
 }
 
 static struct ftrace_ops *
@@ -2380,7 +2359,7 @@
 }
 
 static int
-__ftrace_replace_code(struct dyn_ftrace *rec, int enable)
+__ftrace_replace_code(struct dyn_ftrace *rec, bool enable)
 {
 	unsigned long ftrace_old_addr;
 	unsigned long ftrace_addr;
@@ -2412,13 +2391,15 @@
 		return ftrace_modify_call(rec, ftrace_old_addr, ftrace_addr);
 	}
 
-	return -1; /* unknow ftrace bug */
+	return -1; /* unknown ftrace bug */
 }
 
-void __weak ftrace_replace_code(int enable)
+void __weak ftrace_replace_code(int mod_flags)
 {
 	struct dyn_ftrace *rec;
 	struct ftrace_page *pg;
+	bool enable = mod_flags & FTRACE_MODIFY_ENABLE_FL;
+	int schedulable = mod_flags & FTRACE_MODIFY_MAY_SLEEP_FL;
 	int failed;
 
 	if (unlikely(ftrace_disabled))
@@ -2435,6 +2416,8 @@
 			/* Stop processing */
 			return;
 		}
+		if (schedulable)
+			cond_resched();
 	} while_for_each_ftrace_rec();
 }
 
@@ -2548,8 +2531,12 @@
 void ftrace_modify_all_code(int command)
 {
 	int update = command & FTRACE_UPDATE_TRACE_FUNC;
+	int mod_flags = 0;
 	int err = 0;
 
+	if (command & FTRACE_MAY_SLEEP)
+		mod_flags = FTRACE_MODIFY_MAY_SLEEP_FL;
+
 	/*
 	 * If the ftrace_caller calls a ftrace_ops func directly,
 	 * we need to make sure that it only traces functions it
@@ -2567,9 +2554,9 @@
 	}
 
 	if (command & FTRACE_UPDATE_CALLS)
-		ftrace_replace_code(1);
+		ftrace_replace_code(mod_flags | FTRACE_MODIFY_ENABLE_FL);
 	else if (command & FTRACE_DISABLE_CALLS)
-		ftrace_replace_code(0);
+		ftrace_replace_code(mod_flags);
 
 	if (update && ftrace_trace_function != ftrace_ops_list_func) {
 		function_trace_op = set_function_trace_op;
@@ -2682,7 +2669,7 @@
 	update_all_ops = false;
 }
 
-static int ftrace_startup(struct ftrace_ops *ops, int command)
+int ftrace_startup(struct ftrace_ops *ops, int command)
 {
 	int ret;
 
@@ -2724,7 +2711,7 @@
 	return 0;
 }
 
-static int ftrace_shutdown(struct ftrace_ops *ops, int command)
+int ftrace_shutdown(struct ftrace_ops *ops, int command)
 {
 	int ret;
 
@@ -2828,7 +2815,7 @@
 		 * synchornize_rcu_tasks() will wait for those tasks to
 		 * execute and either schedule voluntarily or enter user space.
 		 */
-		if (IS_ENABLED(CONFIG_PREEMPT))
+		if (IS_ENABLED(CONFIG_PREEMPTION))
 			synchronize_rcu_tasks();
 
  free_ops:
@@ -2951,14 +2938,13 @@
 			p = &pg->records[i];
 			p->flags = rec_flags;
 
-#ifndef CC_USING_NOP_MCOUNT
 			/*
 			 * Do the initial record conversion from mcount jump
 			 * to the NOP instructions.
 			 */
-			if (!ftrace_code_disable(mod, p))
+			if (!__is_defined(CC_USING_NOP_MCOUNT) &&
+			    !ftrace_code_disable(mod, p))
 				break;
-#endif
 
 			update_cnt++;
 		}
@@ -3017,7 +3003,7 @@
 	int cnt;
 
 	if (!num_to_init)
-		return 0;
+		return NULL;
 
 	start_pg = pg = kzalloc(sizeof(*pg), GFP_KERNEL);
 	if (!pg)
@@ -3110,6 +3096,14 @@
 		hnd = &iter->probe_entry->hlist;
 
 	hash = iter->probe->ops.func_hash->filter_hash;
+
+	/*
+	 * A probe being registered may temporarily have an empty hash
+	 * and it's at the end of the func_probes list.
+	 */
+	if (!hash || hash == EMPTY_HASH)
+		return NULL;
+
 	size = 1 << hash->size_bits;
 
  retry:
@@ -3493,6 +3487,11 @@
 ftrace_avail_open(struct inode *inode, struct file *file)
 {
 	struct ftrace_iterator *iter;
+	int ret;
+
+	ret = security_locked_down(LOCKDOWN_TRACEFS);
+	if (ret)
+		return ret;
 
 	if (unlikely(ftrace_disabled))
 		return -ENODEV;
@@ -3512,6 +3511,15 @@
 {
 	struct ftrace_iterator *iter;
 
+	/*
+	 * This shows us what functions are currently being
+	 * traced and by what. Not sure if we want lockdown
+	 * to hide such critical information for an admin.
+	 * Although, perhaps it can show information we don't
+	 * want people to see, but if something is tracing
+	 * something, we probably want to know about it.
+	 */
+
 	iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter));
 	if (!iter)
 		return -ENOMEM;
@@ -3547,21 +3555,22 @@
 	struct ftrace_hash *hash;
 	struct list_head *mod_head;
 	struct trace_array *tr = ops->private;
-	int ret = 0;
+	int ret = -ENOMEM;
 
 	ftrace_ops_init(ops);
 
 	if (unlikely(ftrace_disabled))
 		return -ENODEV;
 
+	if (tracing_check_open_get_tr(tr))
+		return -ENODEV;
+
 	iter = kzalloc(sizeof(*iter), GFP_KERNEL);
 	if (!iter)
-		return -ENOMEM;
+		goto out;
 
-	if (trace_parser_get_init(&iter->parser, FTRACE_BUFF_MAX)) {
-		kfree(iter);
-		return -ENOMEM;
-	}
+	if (trace_parser_get_init(&iter->parser, FTRACE_BUFF_MAX))
+		goto out;
 
 	iter->ops = ops;
 	iter->flags = flag;
@@ -3591,13 +3600,13 @@
 
 		if (!iter->hash) {
 			trace_parser_put(&iter->parser);
-			kfree(iter);
-			ret = -ENOMEM;
 			goto out_unlock;
 		}
 	} else
 		iter->hash = hash;
 
+	ret = 0;
+
 	if (file->f_mode & FMODE_READ) {
 		iter->pg = ftrace_pages_start;
 
@@ -3609,7 +3618,6 @@
 			/* Failed */
 			free_ftrace_hash(iter->hash);
 			trace_parser_put(&iter->parser);
-			kfree(iter);
 		}
 	} else
 		file->private_data = iter;
@@ -3617,6 +3625,13 @@
  out_unlock:
 	mutex_unlock(&ops->func_hash->regex_lock);
 
+ out:
+	if (ret) {
+		kfree(iter);
+		if (tr)
+			trace_array_put(tr);
+	}
+
 	return ret;
 }
 
@@ -3625,6 +3640,7 @@
 {
 	struct ftrace_ops *ops = inode->i_private;
 
+	/* Checks for tracefs lockdown */
 	return ftrace_regex_open(ops,
 			FTRACE_ITER_FILTER | FTRACE_ITER_DO_PROBES,
 			inode, file);
@@ -3635,6 +3651,7 @@
 {
 	struct ftrace_ops *ops = inode->i_private;
 
+	/* Checks for tracefs lockdown */
 	return ftrace_regex_open(ops, FTRACE_ITER_NOTRACE,
 				 inode, file);
 }
@@ -3715,6 +3732,31 @@
 }
 
 static int
+add_rec_by_index(struct ftrace_hash *hash, struct ftrace_glob *func_g,
+		 int clear_filter)
+{
+	long index = simple_strtoul(func_g->search, NULL, 0);
+	struct ftrace_page *pg;
+	struct dyn_ftrace *rec;
+
+	/* The index starts at 1 */
+	if (--index < 0)
+		return 0;
+
+	do_for_each_ftrace_rec(pg, rec) {
+		if (pg->index <= index) {
+			index -= pg->index;
+			/* this is a double loop, break goes to the next page */
+			break;
+		}
+		rec = &pg->records[index];
+		enter_record(hash, rec, clear_filter);
+		return 1;
+	} while_for_each_ftrace_rec();
+	return 0;
+}
+
+static int
 ftrace_match_record(struct dyn_ftrace *rec, struct ftrace_glob *func_g,
 		struct ftrace_glob *mod_g, int exclude_mod)
 {
@@ -3782,6 +3824,11 @@
 	if (unlikely(ftrace_disabled))
 		goto out_unlock;
 
+	if (func_g.type == MATCH_INDEX) {
+		found = add_rec_by_index(hash, &func_g, clear_filter);
+		goto out_unlock;
+	}
+
 	do_for_each_ftrace_rec(pg, rec) {
 
 		if (rec->flags & FTRACE_FL_DISABLED)
@@ -3862,7 +3909,7 @@
 static bool module_exists(const char *module)
 {
 	/* All modules have the symbol __this_module */
-	const char this_mod[] = "__this_module";
+	static const char this_mod[] = "__this_module";
 	char modname[MAX_PARAM_PREFIX_LEN + sizeof(this_mod) + 2];
 	unsigned long val;
 	int n;
@@ -4207,10 +4254,13 @@
 	struct ftrace_func_entry *entry;
 	struct ftrace_func_map *map;
 	struct hlist_head *hhd;
-	int size = 1 << mapper->hash.size_bits;
-	int i;
+	int size, i;
+
+	if (!mapper)
+		return;
 
 	if (free_func && mapper->hash.count) {
+		size = 1 << mapper->hash.size_bits;
 		for (i = 0; i < size; i++) {
 			hhd = &mapper->hash.buckets[i];
 			hlist_for_each_entry(entry, hhd, hlist) {
@@ -4302,12 +4352,21 @@
 
 	mutex_unlock(&ftrace_lock);
 
+	/*
+	 * Note, there's a small window here that the func_hash->filter_hash
+	 * may be NULL or empty. Need to be carefule when reading the loop.
+	 */
 	mutex_lock(&probe->ops.func_hash->regex_lock);
 
 	orig_hash = &probe->ops.func_hash->filter_hash;
 	old_hash = *orig_hash;
 	hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, old_hash);
 
+	if (!hash) {
+		ret = -ENOMEM;
+		goto out;
+	}
+
 	ret = ftrace_match_records(hash, glob, strlen(glob));
 
 	/* Nothing found? */
@@ -4496,7 +4555,7 @@
 	if (ftrace_enabled && !ftrace_hash_empty(hash))
 		ftrace_run_modify_code(&probe->ops, FTRACE_UPDATE_CALLS,
 				       &old_hash_ops);
-	synchronize_sched();
+	synchronize_rcu();
 
 	hlist_for_each_entry_safe(entry, tmp, &hhd, hlist) {
 		hlist_del(&entry->hlist);
@@ -4738,7 +4797,7 @@
 ftrace_set_addr(struct ftrace_ops *ops, unsigned long ip, int remove,
 		int reset, int enable)
 {
-	return ftrace_set_hash(ops, 0, 0, ip, remove, reset, enable);
+	return ftrace_set_hash(ops, NULL, 0, ip, remove, reset, enable);
 }
 
 /**
@@ -5002,6 +5061,8 @@
 
 	mutex_unlock(&iter->ops->func_hash->regex_lock);
 	free_ftrace_hash(iter->hash);
+	if (iter->tr)
+		trace_array_put(iter->tr);
 	kfree(iter);
 
 	return 0;
@@ -5159,9 +5220,13 @@
 __ftrace_graph_open(struct inode *inode, struct file *file,
 		    struct ftrace_graph_data *fgd)
 {
-	int ret = 0;
+	int ret;
 	struct ftrace_hash *new_hash = NULL;
 
+	ret = security_locked_down(LOCKDOWN_TRACEFS);
+	if (ret)
+		return ret;
+
 	if (file->f_mode & FMODE_WRITE) {
 		const int size_bits = FTRACE_HASH_DEFAULT_BITS;
 
@@ -5314,7 +5379,7 @@
 		mutex_unlock(&graph_lock);
 
 		/* Wait till all users are no longer using the old hash */
-		synchronize_sched();
+		synchronize_rcu();
 
 		free_ftrace_hash(old_hash);
 	}
@@ -5446,7 +5511,7 @@
 
 /*
  * The name "destroy_filter_files" is really a misnomer. Although
- * in the future, it may actualy delete the files, but this is
+ * in the future, it may actually delete the files, but this is
  * really intended to make sure the ops passed in are disabled
  * and that when this function returns, the caller is free to
  * free the ops.
@@ -5708,7 +5773,7 @@
 	list_for_each_entry_safe(mod_map, n, &ftrace_mod_maps, list) {
 		if (mod_map->mod == mod) {
 			list_del_rcu(&mod_map->list);
-			call_rcu_sched(&mod_map->rcu, ftrace_free_mod_map);
+			call_rcu(&mod_map->rcu, ftrace_free_mod_map);
 			break;
 		}
 	}
@@ -5769,7 +5834,7 @@
 	/*
 	 * If the tracing is enabled, go ahead and enable the record.
 	 *
-	 * The reason not to enable the record immediatelly is the
+	 * The reason not to enable the record immediately is the
 	 * inherent check of ftrace_make_nop/ftrace_make_call for
 	 * correct previous instructions.  Making first the NOP
 	 * conversion puts the module to the correct state, thus
@@ -5928,7 +5993,7 @@
 	struct ftrace_mod_map *mod_map;
 	const char *ret = NULL;
 
-	/* mod_map is freed via call_rcu_sched() */
+	/* mod_map is freed via call_rcu() */
 	preempt_disable();
 	list_for_each_entry_rcu(mod_map, &ftrace_mod_maps, list) {
 		ret = ftrace_func_address_lookup(mod_map, addr, size, off, sym);
@@ -6001,11 +6066,7 @@
 {
 	struct ftrace_func_entry *entry;
 
-	if (ftrace_hash_empty(hash))
-		return;
-
-	entry = __ftrace_lookup_ip(hash, func->ip);
-
+	entry = ftrace_lookup_ip(hash, func->ip);
 	/*
 	 * Do not allow this rec to match again.
 	 * Yeah, it may waste some memory, but will be removed
@@ -6178,7 +6239,7 @@
 }
 #else
 
-static struct ftrace_ops global_ops = {
+struct ftrace_ops global_ops = {
 	.func			= ftrace_stub,
 	.flags			= FTRACE_OPS_FL_RECURSION_SAFE |
 				  FTRACE_OPS_FL_INITIALIZED |
@@ -6195,31 +6256,10 @@
 static inline int ftrace_init_dyn_tracefs(struct dentry *d_tracer) { return 0; }
 static inline void ftrace_startup_enable(int command) { }
 static inline void ftrace_startup_all(int command) { }
-/* Keep as macros so we do not need to define the commands */
-# define ftrace_startup(ops, command)					\
-	({								\
-		int ___ret = __register_ftrace_function(ops);		\
-		if (!___ret)						\
-			(ops)->flags |= FTRACE_OPS_FL_ENABLED;		\
-		___ret;							\
-	})
-# define ftrace_shutdown(ops, command)					\
-	({								\
-		int ___ret = __unregister_ftrace_function(ops);		\
-		if (!___ret)						\
-			(ops)->flags &= ~FTRACE_OPS_FL_ENABLED;		\
-		___ret;							\
-	})
 
 # define ftrace_startup_sysctl()	do { } while (0)
 # define ftrace_shutdown_sysctl()	do { } while (0)
 
-static inline int
-ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip, void *regs)
-{
-	return 1;
-}
-
 static void ftrace_update_trampoline(struct ftrace_ops *ops)
 {
 }
@@ -6250,7 +6290,7 @@
 	tr->ops->func = ftrace_stub;
 }
 
-static inline void
+static nokprobe_inline void
 __ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
 		       struct ftrace_ops *ignored, struct pt_regs *regs)
 {
@@ -6263,11 +6303,14 @@
 
 	/*
 	 * Some of the ops may be dynamically allocated,
-	 * they must be freed after a synchronize_sched().
+	 * they must be freed after a synchronize_rcu().
 	 */
 	preempt_disable_notrace();
 
 	do_for_each_ftrace_op(op, ftrace_ops_list) {
+		/* Stub functions don't need to be called nor tested */
+		if (op->flags & FTRACE_OPS_FL_STUB)
+			continue;
 		/*
 		 * Check the following for each ops before calling their func:
 		 *  if RCU flag is set, then rcu_is_watching() must be true
@@ -6310,11 +6353,13 @@
 {
 	__ftrace_ops_list_func(ip, parent_ip, NULL, regs);
 }
+NOKPROBE_SYMBOL(ftrace_ops_list_func);
 #else
 static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip)
 {
 	__ftrace_ops_list_func(ip, parent_ip, NULL, NULL);
 }
+NOKPROBE_SYMBOL(ftrace_ops_no_ops);
 #endif
 
 /*
@@ -6341,6 +6386,7 @@
 	preempt_enable_notrace();
 	trace_clear_recursion(bit);
 }
+NOKPROBE_SYMBOL(ftrace_ops_assist_func);
 
 /**
  * ftrace_ops_get_func - get the function a trampoline should call
@@ -6434,7 +6480,7 @@
 	rcu_assign_pointer(tr->function_pids, NULL);
 
 	/* Wait till all users are no longer using pid filtering */
-	synchronize_sched();
+	synchronize_rcu();
 
 	trace_free_pid_list(pid_list);
 }
@@ -6521,8 +6567,9 @@
 	struct seq_file *m;
 	int ret = 0;
 
-	if (trace_array_get(tr) < 0)
-		return -ENODEV;
+	ret = tracing_check_open_get_tr(tr);
+	if (ret)
+		return ret;
 
 	if ((file->f_mode & FMODE_WRITE) &&
 	    (file->f_flags & O_TRUNC))
@@ -6581,7 +6628,7 @@
 	rcu_assign_pointer(tr->function_pids, pid_list);
 
 	if (filtered_pids) {
-		synchronize_sched();
+		synchronize_rcu();
 		trace_free_pid_list(filtered_pids);
 	} else if (pid_list) {
 		/* Register a probe to set whether to ignore the tracing of a task */
@@ -6746,353 +6793,3 @@
 	mutex_unlock(&ftrace_lock);
 	return ret;
 }
-
-#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_PID |
-				   FTRACE_OPS_FL_STUB,
-#ifdef FTRACE_GRAPH_TRAMP_ADDR
-	.trampoline		= FTRACE_GRAPH_TRAMP_ADDR,
-	/* trampoline_size is only needed for dynamically allocated tramps */
-#endif
-	ASSIGN_OPS_HASH(graph_ops, &global_ops.local_hash)
-};
-
-void ftrace_graph_sleep_time_control(bool enable)
-{
-	fgraph_sleep_time = enable;
-}
-
-void ftrace_graph_graph_time_control(bool enable)
-{
-	fgraph_graph_time = enable;
-}
-
-int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace)
-{
-	return 0;
-}
-
-/* The callbacks that hook a function */
-trace_func_graph_ret_t ftrace_graph_return =
-			(trace_func_graph_ret_t)ftrace_stub;
-trace_func_graph_ent_t ftrace_graph_entry = ftrace_graph_entry_stub;
-static trace_func_graph_ent_t __ftrace_graph_entry = ftrace_graph_entry_stub;
-
-/* Try to assign a return stack array on FTRACE_RETSTACK_ALLOC_SIZE tasks. */
-static int alloc_retstack_tasklist(struct ftrace_ret_stack **ret_stack_list)
-{
-	int i;
-	int ret = 0;
-	int start = 0, end = FTRACE_RETSTACK_ALLOC_SIZE;
-	struct task_struct *g, *t;
-
-	for (i = 0; i < FTRACE_RETSTACK_ALLOC_SIZE; i++) {
-		ret_stack_list[i] =
-			kmalloc_array(FTRACE_RETFUNC_DEPTH,
-				      sizeof(struct ftrace_ret_stack),
-				      GFP_KERNEL);
-		if (!ret_stack_list[i]) {
-			start = 0;
-			end = i;
-			ret = -ENOMEM;
-			goto free;
-		}
-	}
-
-	read_lock(&tasklist_lock);
-	do_each_thread(g, t) {
-		if (start == end) {
-			ret = -EAGAIN;
-			goto unlock;
-		}
-
-		if (t->ret_stack == NULL) {
-			atomic_set(&t->tracing_graph_pause, 0);
-			atomic_set(&t->trace_overrun, 0);
-			t->curr_ret_stack = -1;
-			t->curr_ret_depth = -1;
-			/* Make sure the tasks see the -1 first: */
-			smp_wmb();
-			t->ret_stack = ret_stack_list[start++];
-		}
-	} while_each_thread(g, t);
-
-unlock:
-	read_unlock(&tasklist_lock);
-free:
-	for (i = start; i < end; i++)
-		kfree(ret_stack_list[i]);
-	return ret;
-}
-
-static void
-ftrace_graph_probe_sched_switch(void *ignore, bool preempt,
-			struct task_struct *prev, struct task_struct *next)
-{
-	unsigned long long timestamp;
-	int index;
-
-	/*
-	 * Does the user want to count the time a function was asleep.
-	 * If so, do not update the time stamps.
-	 */
-	if (fgraph_sleep_time)
-		return;
-
-	timestamp = trace_clock_local();
-
-	prev->ftrace_timestamp = timestamp;
-
-	/* only process tasks that we timestamped */
-	if (!next->ftrace_timestamp)
-		return;
-
-	/*
-	 * Update all the counters in next to make up for the
-	 * time next was sleeping.
-	 */
-	timestamp -= next->ftrace_timestamp;
-
-	for (index = next->curr_ret_stack; index >= 0; index--)
-		next->ret_stack[index].calltime += timestamp;
-}
-
-/* Allocate a return stack for each task */
-static int start_graph_tracing(void)
-{
-	struct ftrace_ret_stack **ret_stack_list;
-	int ret, cpu;
-
-	ret_stack_list = kmalloc_array(FTRACE_RETSTACK_ALLOC_SIZE,
-				       sizeof(struct ftrace_ret_stack *),
-				       GFP_KERNEL);
-
-	if (!ret_stack_list)
-		return -ENOMEM;
-
-	/* The cpu_boot init_task->ret_stack will never be freed */
-	for_each_online_cpu(cpu) {
-		if (!idle_task(cpu)->ret_stack)
-			ftrace_graph_init_idle_task(idle_task(cpu), cpu);
-	}
-
-	do {
-		ret = alloc_retstack_tasklist(ret_stack_list);
-	} while (ret == -EAGAIN);
-
-	if (!ret) {
-		ret = register_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL);
-		if (ret)
-			pr_info("ftrace_graph: Couldn't activate tracepoint"
-				" probe to kernel_sched_switch\n");
-	}
-
-	kfree(ret_stack_list);
-	return ret;
-}
-
-/*
- * Hibernation protection.
- * The state of the current task is too much unstable during
- * suspend/restore to disk. We want to protect against that.
- */
-static int
-ftrace_suspend_notifier_call(struct notifier_block *bl, unsigned long state,
-							void *unused)
-{
-	switch (state) {
-	case PM_HIBERNATION_PREPARE:
-		pause_graph_tracing();
-		break;
-
-	case PM_POST_HIBERNATION:
-		unpause_graph_tracing();
-		break;
-	}
-	return NOTIFY_DONE;
-}
-
-static int ftrace_graph_entry_test(struct ftrace_graph_ent *trace)
-{
-	if (!ftrace_ops_test(&global_ops, trace->func, NULL))
-		return 0;
-	return __ftrace_graph_entry(trace);
-}
-
-/*
- * The function graph tracer should only trace the functions defined
- * by set_ftrace_filter and set_ftrace_notrace. If another function
- * tracer ops is registered, the graph tracer requires testing the
- * function against the global ops, and not just trace any function
- * that any ftrace_ops registered.
- */
-static void update_function_graph_func(void)
-{
-	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 = {
-	.notifier_call = ftrace_suspend_notifier_call,
-};
-
-int register_ftrace_graph(trace_func_graph_ret_t retfunc,
-			trace_func_graph_ent_t entryfunc)
-{
-	int ret = 0;
-
-	mutex_lock(&ftrace_lock);
-
-	/* we currently allow only one tracer registered at a time */
-	if (ftrace_graph_active) {
-		ret = -EBUSY;
-		goto out;
-	}
-
-	register_pm_notifier(&ftrace_suspend_notifier);
-
-	ftrace_graph_active++;
-	ret = start_graph_tracing();
-	if (ret) {
-		ftrace_graph_active--;
-		goto out;
-	}
-
-	ftrace_graph_return = retfunc;
-
-	/*
-	 * Update the indirect function to the entryfunc, and the
-	 * function that gets called to the entry_test first. Then
-	 * call the update fgraph entry function to determine if
-	 * the entryfunc should be called directly or not.
-	 */
-	__ftrace_graph_entry = entryfunc;
-	ftrace_graph_entry = ftrace_graph_entry_test;
-	update_function_graph_func();
-
-	ret = ftrace_startup(&graph_ops, FTRACE_START_FUNC_RET);
-out:
-	mutex_unlock(&ftrace_lock);
-	return ret;
-}
-
-void unregister_ftrace_graph(void)
-{
-	mutex_lock(&ftrace_lock);
-
-	if (unlikely(!ftrace_graph_active))
-		goto out;
-
-	ftrace_graph_active--;
-	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(&graph_ops, FTRACE_STOP_FUNC_RET);
-	unregister_pm_notifier(&ftrace_suspend_notifier);
-	unregister_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL);
-
- out:
-	mutex_unlock(&ftrace_lock);
-}
-
-static DEFINE_PER_CPU(struct ftrace_ret_stack *, idle_ret_stack);
-
-static void
-graph_init_task(struct task_struct *t, struct ftrace_ret_stack *ret_stack)
-{
-	atomic_set(&t->tracing_graph_pause, 0);
-	atomic_set(&t->trace_overrun, 0);
-	t->ftrace_timestamp = 0;
-	/* make curr_ret_stack visible before we add the ret_stack */
-	smp_wmb();
-	t->ret_stack = ret_stack;
-}
-
-/*
- * Allocate a return stack for the idle task. May be the first
- * time through, or it may be done by CPU hotplug online.
- */
-void ftrace_graph_init_idle_task(struct task_struct *t, int cpu)
-{
-	t->curr_ret_stack = -1;
-	t->curr_ret_depth = -1;
-	/*
-	 * The idle task has no parent, it either has its own
-	 * stack or no stack at all.
-	 */
-	if (t->ret_stack)
-		WARN_ON(t->ret_stack != per_cpu(idle_ret_stack, cpu));
-
-	if (ftrace_graph_active) {
-		struct ftrace_ret_stack *ret_stack;
-
-		ret_stack = per_cpu(idle_ret_stack, cpu);
-		if (!ret_stack) {
-			ret_stack =
-				kmalloc_array(FTRACE_RETFUNC_DEPTH,
-					      sizeof(struct ftrace_ret_stack),
-					      GFP_KERNEL);
-			if (!ret_stack)
-				return;
-			per_cpu(idle_ret_stack, cpu) = ret_stack;
-		}
-		graph_init_task(t, ret_stack);
-	}
-}
-
-/* Allocate a return stack for newly created task */
-void ftrace_graph_init_task(struct task_struct *t)
-{
-	/* Make sure we do not use the parent ret_stack */
-	t->ret_stack = NULL;
-	t->curr_ret_stack = -1;
-	t->curr_ret_depth = -1;
-
-	if (ftrace_graph_active) {
-		struct ftrace_ret_stack *ret_stack;
-
-		ret_stack = kmalloc_array(FTRACE_RETFUNC_DEPTH,
-					  sizeof(struct ftrace_ret_stack),
-					  GFP_KERNEL);
-		if (!ret_stack)
-			return;
-		graph_init_task(t, ret_stack);
-	}
-}
-
-void ftrace_graph_exit_task(struct task_struct *t)
-{
-	struct ftrace_ret_stack	*ret_stack = t->ret_stack;
-
-	t->ret_stack = NULL;
-	/* NULL must become visible to IRQs before we free it: */
-	barrier();
-
-	kfree(ret_stack);
-}
-#endif