1 files changed, 628 insertions, 165 deletions

diff --git a/kernel/trace/trace_functions.c b/kernel/trace/trace_functions.c
index b863f93b30f3..c12795c2fb39 100644
--- a/kernel/trace/trace_functions.c
+++ b/kernel/trace/trace_functions.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * ring buffer based function tracer
  *
@@ -13,92 +14,273 @@
 #include <linux/debugfs.h>
 #include <linux/uaccess.h>
 #include <linux/ftrace.h>
+#include <linux/slab.h>
 #include <linux/fs.h>
 
 #include "trace.h"
 
-/* function tracing enabled */
-static int			ftrace_function_enabled;
+static void tracing_start_function_trace(struct trace_array *tr);
+static void tracing_stop_function_trace(struct trace_array *tr);
+static void
+function_trace_call(unsigned long ip, unsigned long parent_ip,
+		    struct ftrace_ops *op, struct ftrace_regs *fregs);
+static void
+function_args_trace_call(unsigned long ip, unsigned long parent_ip,
+			 struct ftrace_ops *op, struct ftrace_regs *fregs);
+static void
+function_stack_trace_call(unsigned long ip, unsigned long parent_ip,
+			  struct ftrace_ops *op, struct ftrace_regs *fregs);
+static void
+function_no_repeats_trace_call(unsigned long ip, unsigned long parent_ip,
+			       struct ftrace_ops *op, struct ftrace_regs *fregs);
+static void
+function_stack_no_repeats_trace_call(unsigned long ip, unsigned long parent_ip,
+				     struct ftrace_ops *op,
+				     struct ftrace_regs *fregs);
+static struct tracer_flags func_flags;
+
+/* Our option */
+enum {
+
+	TRACE_FUNC_NO_OPTS		= 0x0, /* No flags set. */
+	TRACE_FUNC_OPT_STACK		= 0x1,
+	TRACE_FUNC_OPT_NO_REPEATS	= 0x2,
+	TRACE_FUNC_OPT_ARGS		= 0x4,
+
+	/* Update this to next highest bit. */
+	TRACE_FUNC_OPT_HIGHEST_BIT	= 0x8
+};
+
+#define TRACE_FUNC_OPT_MASK	(TRACE_FUNC_OPT_HIGHEST_BIT - 1)
+
+int ftrace_allocate_ftrace_ops(struct trace_array *tr)
+{
+	struct ftrace_ops *ops;
+
+	/* The top level array uses the "global_ops" */
+	if (tr->flags & TRACE_ARRAY_FL_GLOBAL)
+		return 0;
+
+	ops = kzalloc(sizeof(*ops), GFP_KERNEL);
+	if (!ops)
+		return -ENOMEM;
+
+	/* Currently only the non stack version is supported */
+	ops->func = function_trace_call;
+	ops->flags = FTRACE_OPS_FL_PID;
+
+	tr->ops = ops;
+	ops->private = tr;
+
+	return 0;
+}
 
-static struct trace_array	*func_trace;
+void ftrace_free_ftrace_ops(struct trace_array *tr)
+{
+	kfree(tr->ops);
+	tr->ops = NULL;
+}
 
-static void tracing_start_function_trace(void);
-static void tracing_stop_function_trace(void);
+int ftrace_create_function_files(struct trace_array *tr,
+				 struct dentry *parent)
+{
+	int ret;
+	/*
+	 * The top level array uses the "global_ops", and the files are
+	 * created on boot up.
+	 */
+	if (tr->flags & TRACE_ARRAY_FL_GLOBAL)
+		return 0;
+
+	if (!tr->ops)
+		return -EINVAL;
+
+	ret = allocate_fgraph_ops(tr, tr->ops);
+	if (ret) {
+		kfree(tr->ops);
+		return ret;
+	}
+
+	ftrace_create_filter_files(tr->ops, parent);
+
+	return 0;
+}
+
+void ftrace_destroy_function_files(struct trace_array *tr)
+{
+	ftrace_destroy_filter_files(tr->ops);
+	ftrace_free_ftrace_ops(tr);
+	free_fgraph_ops(tr);
+}
+
+static ftrace_func_t select_trace_function(u32 flags_val)
+{
+	switch (flags_val & TRACE_FUNC_OPT_MASK) {
+	case TRACE_FUNC_NO_OPTS:
+		return function_trace_call;
+	case TRACE_FUNC_OPT_ARGS:
+		return function_args_trace_call;
+	case TRACE_FUNC_OPT_STACK:
+		return function_stack_trace_call;
+	case TRACE_FUNC_OPT_NO_REPEATS:
+		return function_no_repeats_trace_call;
+	case TRACE_FUNC_OPT_STACK | TRACE_FUNC_OPT_NO_REPEATS:
+		return function_stack_no_repeats_trace_call;
+	default:
+		return NULL;
+	}
+}
+
+static bool handle_func_repeats(struct trace_array *tr, u32 flags_val)
+{
+	if (!tr->last_func_repeats &&
+	    (flags_val & TRACE_FUNC_OPT_NO_REPEATS)) {
+		tr->last_func_repeats = alloc_percpu(struct trace_func_repeats);
+		if (!tr->last_func_repeats)
+			return false;
+	}
+
+	return true;
+}
 
 static int function_trace_init(struct trace_array *tr)
 {
-	func_trace = tr;
-	tr->trace_buffer.cpu = get_cpu();
-	put_cpu();
+	ftrace_func_t func;
+	/*
+	 * Instance trace_arrays get their ops allocated
+	 * at instance creation. Unless it failed
+	 * the allocation.
+	 */
+	if (!tr->ops)
+		return -ENOMEM;
+
+	func = select_trace_function(tr->current_trace_flags->val);
+	if (!func)
+		return -EINVAL;
+
+	if (!handle_func_repeats(tr, tr->current_trace_flags->val))
+		return -ENOMEM;
+
+	ftrace_init_array_ops(tr, func);
+
+	tr->array_buffer.cpu = raw_smp_processor_id();
 
 	tracing_start_cmdline_record();
-	tracing_start_function_trace();
+	tracing_start_function_trace(tr);
 	return 0;
 }
 
 static void function_trace_reset(struct trace_array *tr)
 {
-	tracing_stop_function_trace();
+	tracing_stop_function_trace(tr);
 	tracing_stop_cmdline_record();
+	ftrace_reset_array_ops(tr);
 }
 
 static void function_trace_start(struct trace_array *tr)
 {
-	tracing_reset_online_cpus(&tr->trace_buffer);
+	tracing_reset_online_cpus(&tr->array_buffer);
 }
 
-/* Our option */
-enum {
-	TRACE_FUNC_OPT_STACK	= 0x1,
-};
-
-static struct tracer_flags func_flags;
+/* fregs are guaranteed not to be NULL if HAVE_DYNAMIC_FTRACE_WITH_ARGS is set */
+#if defined(CONFIG_FUNCTION_GRAPH_TRACER) && defined(CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS)
+static __always_inline unsigned long
+function_get_true_parent_ip(unsigned long parent_ip, struct ftrace_regs *fregs)
+{
+	unsigned long true_parent_ip;
+	int idx = 0;
+
+	true_parent_ip = parent_ip;
+	if (unlikely(parent_ip == (unsigned long)&return_to_handler) && fregs)
+		true_parent_ip = ftrace_graph_ret_addr(current, &idx, parent_ip,
+				(unsigned long *)ftrace_regs_get_stack_pointer(fregs));
+	return true_parent_ip;
+}
+#else
+static __always_inline unsigned long
+function_get_true_parent_ip(unsigned long parent_ip, struct ftrace_regs *fregs)
+{
+	return parent_ip;
+}
+#endif
 
 static void
 function_trace_call(unsigned long ip, unsigned long parent_ip,
-		    struct ftrace_ops *op, struct pt_regs *pt_regs)
+		    struct ftrace_ops *op, struct ftrace_regs *fregs)
 {
-	struct trace_array *tr = func_trace;
-	struct trace_array_cpu *data;
-	unsigned long flags;
+	struct trace_array *tr = op->private;
+	unsigned int trace_ctx;
 	int bit;
-	int cpu;
-	int pc;
 
-	if (unlikely(!ftrace_function_enabled))
+	if (unlikely(!tr->function_enabled))
+		return;
+
+	bit = ftrace_test_recursion_trylock(ip, parent_ip);
+	if (bit < 0)
 		return;
 
-	pc = preempt_count();
-	preempt_disable_notrace();
+	parent_ip = function_get_true_parent_ip(parent_ip, fregs);
 
-	bit = trace_test_and_set_recursion(TRACE_FTRACE_START, TRACE_FTRACE_MAX);
+	trace_ctx = tracing_gen_ctx_dec();
+
+	trace_function(tr, ip, parent_ip, trace_ctx, NULL);
+
+	ftrace_test_recursion_unlock(bit);
+}
+
+static void
+function_args_trace_call(unsigned long ip, unsigned long parent_ip,
+			 struct ftrace_ops *op, struct ftrace_regs *fregs)
+{
+	struct trace_array *tr = op->private;
+	unsigned int trace_ctx;
+	int bit;
+
+	if (unlikely(!tr->function_enabled))
+		return;
+
+	bit = ftrace_test_recursion_trylock(ip, parent_ip);
 	if (bit < 0)
-		goto out;
+		return;
 
-	cpu = smp_processor_id();
-	data = per_cpu_ptr(tr->trace_buffer.data, cpu);
-	if (!atomic_read(&data->disabled)) {
-		local_save_flags(flags);
-		trace_function(tr, ip, parent_ip, flags, pc);
-	}
-	trace_clear_recursion(bit);
+	trace_ctx = tracing_gen_ctx();
 
- out:
-	preempt_enable_notrace();
+	trace_function(tr, ip, parent_ip, trace_ctx, fregs);
+
+	ftrace_test_recursion_unlock(bit);
 }
 
+#ifdef CONFIG_UNWINDER_ORC
+/*
+ * Skip 2:
+ *
+ *   function_stack_trace_call()
+ *   ftrace_call()
+ */
+#define STACK_SKIP 2
+#else
+/*
+ * Skip 3:
+ *   __trace_stack()
+ *   function_stack_trace_call()
+ *   ftrace_call()
+ */
+#define STACK_SKIP 3
+#endif
+
 static void
 function_stack_trace_call(unsigned long ip, unsigned long parent_ip,
-			  struct ftrace_ops *op, struct pt_regs *pt_regs)
+			  struct ftrace_ops *op, struct ftrace_regs *fregs)
 {
-	struct trace_array *tr = func_trace;
+	struct trace_array *tr = op->private;
 	struct trace_array_cpu *data;
 	unsigned long flags;
 	long disabled;
 	int cpu;
-	int pc;
+	unsigned int trace_ctx;
+	int skip = STACK_SKIP;
 
-	if (unlikely(!ftrace_function_enabled))
+	if (unlikely(!tr->function_enabled))
 		return;
 
 	/*
@@ -106,274 +288,545 @@ function_stack_trace_call(unsigned long ip, unsigned long parent_ip,
 	 * recursive protection is performed.
 	 */
 	local_irq_save(flags);
+	parent_ip = function_get_true_parent_ip(parent_ip, fregs);
 	cpu = raw_smp_processor_id();
-	data = per_cpu_ptr(tr->trace_buffer.data, cpu);
-	disabled = atomic_inc_return(&data->disabled);
+	data = per_cpu_ptr(tr->array_buffer.data, cpu);
+	disabled = local_inc_return(&data->disabled);
 
 	if (likely(disabled == 1)) {
-		pc = preempt_count();
-		trace_function(tr, ip, parent_ip, flags, pc);
-		/*
-		 * skip over 5 funcs:
-		 *    __ftrace_trace_stack,
-		 *    __trace_stack,
-		 *    function_stack_trace_call
-		 *    ftrace_list_func
-		 *    ftrace_call
-		 */
-		__trace_stack(tr, flags, 5, pc);
+		trace_ctx = tracing_gen_ctx_flags(flags);
+		trace_function(tr, ip, parent_ip, trace_ctx, NULL);
+#ifdef CONFIG_UNWINDER_FRAME_POINTER
+		if (ftrace_pids_enabled(op))
+			skip++;
+#endif
+		__trace_stack(tr, trace_ctx, skip);
 	}
 
-	atomic_dec(&data->disabled);
+	local_dec(&data->disabled);
 	local_irq_restore(flags);
 }
 
+static inline bool is_repeat_check(struct trace_array *tr,
+				   struct trace_func_repeats *last_info,
+				   unsigned long ip, unsigned long parent_ip)
+{
+	if (last_info->ip == ip &&
+	    last_info->parent_ip == parent_ip &&
+	    last_info->count < U16_MAX) {
+		last_info->ts_last_call =
+			ring_buffer_time_stamp(tr->array_buffer.buffer);
+		last_info->count++;
+		return true;
+	}
+
+	return false;
+}
 
-static struct ftrace_ops trace_ops __read_mostly =
+static inline void process_repeats(struct trace_array *tr,
+				   unsigned long ip, unsigned long parent_ip,
+				   struct trace_func_repeats *last_info,
+				   unsigned int trace_ctx)
 {
-	.func = function_trace_call,
-	.flags = FTRACE_OPS_FL_GLOBAL | FTRACE_OPS_FL_RECURSION_SAFE,
-};
+	if (last_info->count) {
+		trace_last_func_repeats(tr, last_info, trace_ctx);
+		last_info->count = 0;
+	}
+
+	last_info->ip = ip;
+	last_info->parent_ip = parent_ip;
+}
 
-static struct ftrace_ops trace_stack_ops __read_mostly =
+static void
+function_no_repeats_trace_call(unsigned long ip, unsigned long parent_ip,
+			       struct ftrace_ops *op,
+			       struct ftrace_regs *fregs)
 {
-	.func = function_stack_trace_call,
-	.flags = FTRACE_OPS_FL_GLOBAL | FTRACE_OPS_FL_RECURSION_SAFE,
-};
+	struct trace_func_repeats *last_info;
+	struct trace_array *tr = op->private;
+	unsigned int trace_ctx;
+	int bit;
+
+	if (unlikely(!tr->function_enabled))
+		return;
+
+	bit = ftrace_test_recursion_trylock(ip, parent_ip);
+	if (bit < 0)
+		return;
+
+	parent_ip = function_get_true_parent_ip(parent_ip, fregs);
+	if (!tracer_tracing_is_on(tr))
+		goto out;
+
+	/*
+	 * An interrupt may happen at any place here. But as far as I can see,
+	 * the only damage that this can cause is to mess up the repetition
+	 * counter without valuable data being lost.
+	 * TODO: think about a solution that is better than just hoping to be
+	 * lucky.
+	 */
+	last_info = this_cpu_ptr(tr->last_func_repeats);
+	if (is_repeat_check(tr, last_info, ip, parent_ip))
+		goto out;
+
+	trace_ctx = tracing_gen_ctx_dec();
+	process_repeats(tr, ip, parent_ip, last_info, trace_ctx);
+
+	trace_function(tr, ip, parent_ip, trace_ctx, NULL);
+
+out:
+	ftrace_test_recursion_unlock(bit);
+}
+
+static void
+function_stack_no_repeats_trace_call(unsigned long ip, unsigned long parent_ip,
+				     struct ftrace_ops *op,
+				     struct ftrace_regs *fregs)
+{
+	struct trace_func_repeats *last_info;
+	struct trace_array *tr = op->private;
+	struct trace_array_cpu *data;
+	unsigned long flags;
+	long disabled;
+	int cpu;
+	unsigned int trace_ctx;
+
+	if (unlikely(!tr->function_enabled))
+		return;
+
+	/*
+	 * Need to use raw, since this must be called before the
+	 * recursive protection is performed.
+	 */
+	local_irq_save(flags);
+	parent_ip = function_get_true_parent_ip(parent_ip, fregs);
+	cpu = raw_smp_processor_id();
+	data = per_cpu_ptr(tr->array_buffer.data, cpu);
+	disabled = local_inc_return(&data->disabled);
+
+	if (likely(disabled == 1)) {
+		last_info = per_cpu_ptr(tr->last_func_repeats, cpu);
+		if (is_repeat_check(tr, last_info, ip, parent_ip))
+			goto out;
+
+		trace_ctx = tracing_gen_ctx_flags(flags);
+		process_repeats(tr, ip, parent_ip, last_info, trace_ctx);
+
+		trace_function(tr, ip, parent_ip, trace_ctx, NULL);
+		__trace_stack(tr, trace_ctx, STACK_SKIP);
+	}
+
+ out:
+	local_dec(&data->disabled);
+	local_irq_restore(flags);
+}
 
 static struct tracer_opt func_opts[] = {
 #ifdef CONFIG_STACKTRACE
 	{ TRACER_OPT(func_stack_trace, TRACE_FUNC_OPT_STACK) },
 #endif
+	{ TRACER_OPT(func-no-repeats, TRACE_FUNC_OPT_NO_REPEATS) },
+#ifdef CONFIG_FUNCTION_TRACE_ARGS
+	{ TRACER_OPT(func-args, TRACE_FUNC_OPT_ARGS) },
+#endif
 	{ } /* Always set a last empty entry */
 };
 
 static struct tracer_flags func_flags = {
-	.val = 0, /* By default: all flags disabled */
+	.val = TRACE_FUNC_NO_OPTS, /* By default: all flags disabled */
 	.opts = func_opts
 };
 
-static void tracing_start_function_trace(void)
+static void tracing_start_function_trace(struct trace_array *tr)
 {
-	ftrace_function_enabled = 0;
-
-	if (func_flags.val & TRACE_FUNC_OPT_STACK)
-		register_ftrace_function(&trace_stack_ops);
-	else
-		register_ftrace_function(&trace_ops);
-
-	ftrace_function_enabled = 1;
+	tr->function_enabled = 0;
+	register_ftrace_function(tr->ops);
+	tr->function_enabled = 1;
 }
 
-static void tracing_stop_function_trace(void)
+static void tracing_stop_function_trace(struct trace_array *tr)
 {
-	ftrace_function_enabled = 0;
-
-	if (func_flags.val & TRACE_FUNC_OPT_STACK)
-		unregister_ftrace_function(&trace_stack_ops);
-	else
-		unregister_ftrace_function(&trace_ops);
+	tr->function_enabled = 0;
+	unregister_ftrace_function(tr->ops);
 }
 
-static int func_set_flag(u32 old_flags, u32 bit, int set)
+static struct tracer function_trace;
+
+static int
+func_set_flag(struct trace_array *tr, u32 old_flags, u32 bit, int set)
 {
-	switch (bit) {
-	case TRACE_FUNC_OPT_STACK:
-		/* do nothing if already set */
-		if (!!set == !!(func_flags.val & TRACE_FUNC_OPT_STACK))
-			break;
-
-		if (set) {
-			unregister_ftrace_function(&trace_ops);
-			register_ftrace_function(&trace_stack_ops);
-		} else {
-			unregister_ftrace_function(&trace_stack_ops);
-			register_ftrace_function(&trace_ops);
-		}
-
-		break;
-	default:
+	ftrace_func_t func;
+	u32 new_flags;
+
+	/* Do nothing if already set. */
+	if (!!set == !!(tr->current_trace_flags->val & bit))
+		return 0;
+
+	/* We can change this flag only when not running. */
+	if (tr->current_trace != &function_trace)
+		return 0;
+
+	new_flags = (tr->current_trace_flags->val & ~bit) | (set ? bit : 0);
+	func = select_trace_function(new_flags);
+	if (!func)
 		return -EINVAL;
-	}
+
+	/* Check if there's anything to change. */
+	if (tr->ops->func == func)
+		return 0;
+
+	if (!handle_func_repeats(tr, new_flags))
+		return -ENOMEM;
+
+	unregister_ftrace_function(tr->ops);
+	tr->ops->func = func;
+	register_ftrace_function(tr->ops);
 
 	return 0;
 }
 
-static struct tracer function_trace __read_mostly =
+static struct tracer function_trace __tracer_data =
 {
 	.name		= "function",
 	.init		= function_trace_init,
 	.reset		= function_trace_reset,
 	.start		= function_trace_start,
-	.wait_pipe	= poll_wait_pipe,
-	.flags		= &func_flags,
+	.default_flags	= &func_flags,
 	.set_flag	= func_set_flag,
+	.allow_instances = true,
 #ifdef CONFIG_FTRACE_SELFTEST
 	.selftest	= trace_selftest_startup_function,
 #endif
 };
 
 #ifdef CONFIG_DYNAMIC_FTRACE
-static int update_count(void **data)
+static void update_traceon_count(struct ftrace_probe_ops *ops,
+				 unsigned long ip,
+				 struct trace_array *tr, bool on,
+				 void *data)
 {
-	unsigned long *count = (long *)data;
+	struct ftrace_func_mapper *mapper = data;
+	long *count;
+	long old_count;
 
-	if (!*count)
-		return 0;
+	/*
+	 * Tracing gets disabled (or enabled) once per count.
+	 * This function can be called at the same time on multiple CPUs.
+	 * It is fine if both disable (or enable) tracing, as disabling
+	 * (or enabling) the second time doesn't do anything as the
+	 * state of the tracer is already disabled (or enabled).
+	 * What needs to be synchronized in this case is that the count
+	 * only gets decremented once, even if the tracer is disabled
+	 * (or enabled) twice, as the second one is really a nop.
+	 *
+	 * The memory barriers guarantee that we only decrement the
+	 * counter once. First the count is read to a local variable
+	 * and a read barrier is used to make sure that it is loaded
+	 * before checking if the tracer is in the state we want.
+	 * If the tracer is not in the state we want, then the count
+	 * is guaranteed to be the old count.
+	 *
+	 * Next the tracer is set to the state we want (disabled or enabled)
+	 * then a write memory barrier is used to make sure that
+	 * the new state is visible before changing the counter by
+	 * one minus the old counter. This guarantees that another CPU
+	 * executing this code will see the new state before seeing
+	 * the new counter value, and would not do anything if the new
+	 * counter is seen.
+	 *
+	 * Note, there is no synchronization between this and a user
+	 * setting the tracing_on file. But we currently don't care
+	 * about that.
+	 */
+	count = (long *)ftrace_func_mapper_find_ip(mapper, ip);
+	old_count = *count;
 
-	if (*count != -1)
-		(*count)--;
+	if (old_count <= 0)
+		return;
 
-	return 1;
-}
+	/* Make sure we see count before checking tracing state */
+	smp_rmb();
 
-static void
-ftrace_traceon_count(unsigned long ip, unsigned long parent_ip, void **data)
-{
-	if (tracing_is_on())
+	if (on == !!tracer_tracing_is_on(tr))
 		return;
 
-	if (update_count(data))
-		tracing_on();
+	if (on)
+		tracer_tracing_on(tr);
+	else
+		tracer_tracing_off(tr);
+
+	/* Make sure tracing state is visible before updating count */
+	smp_wmb();
+
+	*count = old_count - 1;
 }
 
 static void
-ftrace_traceoff_count(unsigned long ip, unsigned long parent_ip, void **data)
+ftrace_traceon_count(unsigned long ip, unsigned long parent_ip,
+		     struct trace_array *tr, struct ftrace_probe_ops *ops,
+		     void *data)
 {
-	if (!tracing_is_on())
-		return;
+	update_traceon_count(ops, ip, tr, 1, data);
+}
 
-	if (update_count(data))
-		tracing_off();
+static void
+ftrace_traceoff_count(unsigned long ip, unsigned long parent_ip,
+		      struct trace_array *tr, struct ftrace_probe_ops *ops,
+		      void *data)
+{
+	update_traceon_count(ops, ip, tr, 0, data);
 }
 
 static void
-ftrace_traceon(unsigned long ip, unsigned long parent_ip, void **data)
+ftrace_traceon(unsigned long ip, unsigned long parent_ip,
+	       struct trace_array *tr, struct ftrace_probe_ops *ops,
+	       void *data)
 {
-	if (tracing_is_on())
+	if (tracer_tracing_is_on(tr))
 		return;
 
-	tracing_on();
+	tracer_tracing_on(tr);
 }
 
 static void
-ftrace_traceoff(unsigned long ip, unsigned long parent_ip, void **data)
+ftrace_traceoff(unsigned long ip, unsigned long parent_ip,
+		struct trace_array *tr, struct ftrace_probe_ops *ops,
+		void *data)
 {
-	if (!tracing_is_on())
+	if (!tracer_tracing_is_on(tr))
 		return;
 
-	tracing_off();
+	tracer_tracing_off(tr);
 }
 
+#ifdef CONFIG_UNWINDER_ORC
+/*
+ * Skip 3:
+ *
+ *   function_trace_probe_call()
+ *   ftrace_ops_assist_func()
+ *   ftrace_call()
+ */
+#define FTRACE_STACK_SKIP 3
+#else
 /*
- * Skip 4:
+ * Skip 5:
+ *
+ *   __trace_stack()
  *   ftrace_stacktrace()
  *   function_trace_probe_call()
- *   ftrace_ops_list_func()
+ *   ftrace_ops_assist_func()
  *   ftrace_call()
  */
-#define STACK_SKIP 4
+#define FTRACE_STACK_SKIP 5
+#endif
+
+static __always_inline void trace_stack(struct trace_array *tr)
+{
+	__trace_stack(tr, tracing_gen_ctx_dec(), FTRACE_STACK_SKIP);
+}
 
 static void
-ftrace_stacktrace(unsigned long ip, unsigned long parent_ip, void **data)
+ftrace_stacktrace(unsigned long ip, unsigned long parent_ip,
+		  struct trace_array *tr, struct ftrace_probe_ops *ops,
+		  void *data)
 {
-	trace_dump_stack(STACK_SKIP);
+	trace_stack(tr);
 }
 
 static void
-ftrace_stacktrace_count(unsigned long ip, unsigned long parent_ip, void **data)
+ftrace_stacktrace_count(unsigned long ip, unsigned long parent_ip,
+			struct trace_array *tr, struct ftrace_probe_ops *ops,
+			void *data)
 {
+	struct ftrace_func_mapper *mapper = data;
+	long *count;
+	long old_count;
+	long new_count;
+
 	if (!tracing_is_on())
 		return;
 
-	if (update_count(data))
-		trace_dump_stack(STACK_SKIP);
+	/* unlimited? */
+	if (!mapper) {
+		trace_stack(tr);
+		return;
+	}
+
+	count = (long *)ftrace_func_mapper_find_ip(mapper, ip);
+
+	/*
+	 * Stack traces should only execute the number of times the
+	 * user specified in the counter.
+	 */
+	do {
+		old_count = *count;
+
+		if (!old_count)
+			return;
+
+		new_count = old_count - 1;
+		new_count = cmpxchg(count, old_count, new_count);
+		if (new_count == old_count)
+			trace_stack(tr);
+
+		if (!tracing_is_on())
+			return;
+
+	} while (new_count != old_count);
+}
+
+static int update_count(struct ftrace_probe_ops *ops, unsigned long ip,
+			void *data)
+{
+	struct ftrace_func_mapper *mapper = data;
+	long *count = NULL;
+
+	if (mapper)
+		count = (long *)ftrace_func_mapper_find_ip(mapper, ip);
+
+	if (count) {
+		if (*count <= 0)
+			return 0;
+		(*count)--;
+	}
+
+	return 1;
 }
 
 static void
-ftrace_dump_probe(unsigned long ip, unsigned long parent_ip, void **data)
+ftrace_dump_probe(unsigned long ip, unsigned long parent_ip,
+		  struct trace_array *tr, struct ftrace_probe_ops *ops,
+		  void *data)
 {
-	if (update_count(data))
+	if (update_count(ops, ip, data))
 		ftrace_dump(DUMP_ALL);
 }
 
 /* Only dump the current CPU buffer. */
 static void
-ftrace_cpudump_probe(unsigned long ip, unsigned long parent_ip, void **data)
+ftrace_cpudump_probe(unsigned long ip, unsigned long parent_ip,
+		     struct trace_array *tr, struct ftrace_probe_ops *ops,
+		     void *data)
 {
-	if (update_count(data))
+	if (update_count(ops, ip, data))
 		ftrace_dump(DUMP_ORIG);
 }
 
 static int
 ftrace_probe_print(const char *name, struct seq_file *m,
-		   unsigned long ip, void *data)
+		   unsigned long ip, struct ftrace_probe_ops *ops,
+		   void *data)
 {
-	long count = (long)data;
+	struct ftrace_func_mapper *mapper = data;
+	long *count = NULL;
 
 	seq_printf(m, "%ps:%s", (void *)ip, name);
 
-	if (count == -1)
-		seq_printf(m, ":unlimited\n");
+	if (mapper)
+		count = (long *)ftrace_func_mapper_find_ip(mapper, ip);
+
+	if (count)
+		seq_printf(m, ":count=%ld\n", *count);
 	else
-		seq_printf(m, ":count=%ld\n", count);
+		seq_puts(m, ":unlimited\n");
 
 	return 0;
 }
 
 static int
 ftrace_traceon_print(struct seq_file *m, unsigned long ip,
-			 struct ftrace_probe_ops *ops, void *data)
+		     struct ftrace_probe_ops *ops,
+		     void *data)
 {
-	return ftrace_probe_print("traceon", m, ip, data);
+	return ftrace_probe_print("traceon", m, ip, ops, data);
 }
 
 static int
 ftrace_traceoff_print(struct seq_file *m, unsigned long ip,
 			 struct ftrace_probe_ops *ops, void *data)
 {
-	return ftrace_probe_print("traceoff", m, ip, data);
+	return ftrace_probe_print("traceoff", m, ip, ops, data);
 }
 
 static int
 ftrace_stacktrace_print(struct seq_file *m, unsigned long ip,
 			struct ftrace_probe_ops *ops, void *data)
 {
-	return ftrace_probe_print("stacktrace", m, ip, data);
+	return ftrace_probe_print("stacktrace", m, ip, ops, data);
 }
 
 static int
 ftrace_dump_print(struct seq_file *m, unsigned long ip,
 			struct ftrace_probe_ops *ops, void *data)
 {
-	return ftrace_probe_print("dump", m, ip, data);
+	return ftrace_probe_print("dump", m, ip, ops, data);
 }
 
 static int
 ftrace_cpudump_print(struct seq_file *m, unsigned long ip,
 			struct ftrace_probe_ops *ops, void *data)
 {
-	return ftrace_probe_print("cpudump", m, ip, data);
+	return ftrace_probe_print("cpudump", m, ip, ops, data);
+}
+
+
+static int
+ftrace_count_init(struct ftrace_probe_ops *ops, struct trace_array *tr,
+		  unsigned long ip, void *init_data, void **data)
+{
+	struct ftrace_func_mapper *mapper = *data;
+
+	if (!mapper) {
+		mapper = allocate_ftrace_func_mapper();
+		if (!mapper)
+			return -ENOMEM;
+		*data = mapper;
+	}
+
+	return ftrace_func_mapper_add_ip(mapper, ip, init_data);
+}
+
+static void
+ftrace_count_free(struct ftrace_probe_ops *ops, struct trace_array *tr,
+		  unsigned long ip, void *data)
+{
+	struct ftrace_func_mapper *mapper = data;
+
+	if (!ip) {
+		free_ftrace_func_mapper(mapper, NULL);
+		return;
+	}
+
+	ftrace_func_mapper_remove_ip(mapper, ip);
 }
 
 static struct ftrace_probe_ops traceon_count_probe_ops = {
 	.func			= ftrace_traceon_count,
 	.print			= ftrace_traceon_print,
+	.init			= ftrace_count_init,
+	.free			= ftrace_count_free,
 };
 
 static struct ftrace_probe_ops traceoff_count_probe_ops = {
 	.func			= ftrace_traceoff_count,
 	.print			= ftrace_traceoff_print,
+	.init			= ftrace_count_init,
+	.free			= ftrace_count_free,
 };
 
 static struct ftrace_probe_ops stacktrace_count_probe_ops = {
 	.func			= ftrace_stacktrace_count,
 	.print			= ftrace_stacktrace_print,
+	.init			= ftrace_count_init,
+	.free			= ftrace_count_free,
 };
 
 static struct ftrace_probe_ops dump_probe_ops = {
 	.func			= ftrace_dump_probe,
 	.print			= ftrace_dump_print,
+	.init			= ftrace_count_init,
+	.free			= ftrace_count_free,
 };
 
 static struct ftrace_probe_ops cpudump_probe_ops = {
@@ -397,7 +850,8 @@ static struct ftrace_probe_ops stacktrace_probe_ops = {
 };
 
 static int
-ftrace_trace_probe_callback(struct ftrace_probe_ops *ops,
+ftrace_trace_probe_callback(struct trace_array *tr,
+			    struct ftrace_probe_ops *ops,
 			    struct ftrace_hash *hash, char *glob,
 			    char *cmd, char *param, int enable)
 {
@@ -409,10 +863,8 @@ ftrace_trace_probe_callback(struct ftrace_probe_ops *ops,
 	if (!enable)
 		return -EINVAL;
 
-	if (glob[0] == '!') {
-		unregister_ftrace_function_probe_func(glob+1, ops);
-		return 0;
-	}
+	if (glob[0] == '!')
+		return unregister_ftrace_function_probe_func(glob+1, tr, ops);
 
 	if (!param)
 		goto out_reg;
@@ -431,62 +883,74 @@ ftrace_trace_probe_callback(struct ftrace_probe_ops *ops,
 		return ret;
 
  out_reg:
-	ret = register_ftrace_function_probe(glob, ops, count);
+	ret = register_ftrace_function_probe(glob, tr, ops, count);
 
 	return ret < 0 ? ret : 0;
 }
 
 static int
-ftrace_trace_onoff_callback(struct ftrace_hash *hash,
+ftrace_trace_onoff_callback(struct trace_array *tr, struct ftrace_hash *hash,
 			    char *glob, char *cmd, char *param, int enable)
 {
 	struct ftrace_probe_ops *ops;
 
+	if (!tr)
+		return -ENODEV;
+
 	/* we register both traceon and traceoff to this callback */
 	if (strcmp(cmd, "traceon") == 0)
 		ops = param ? &traceon_count_probe_ops : &traceon_probe_ops;
 	else
 		ops = param ? &traceoff_count_probe_ops : &traceoff_probe_ops;
 
-	return ftrace_trace_probe_callback(ops, hash, glob, cmd,
+	return ftrace_trace_probe_callback(tr, ops, hash, glob, cmd,
 					   param, enable);
 }
 
 static int
-ftrace_stacktrace_callback(struct ftrace_hash *hash,
+ftrace_stacktrace_callback(struct trace_array *tr, struct ftrace_hash *hash,
 			   char *glob, char *cmd, char *param, int enable)
 {
 	struct ftrace_probe_ops *ops;
 
+	if (!tr)
+		return -ENODEV;
+
 	ops = param ? &stacktrace_count_probe_ops : &stacktrace_probe_ops;
 
-	return ftrace_trace_probe_callback(ops, hash, glob, cmd,
+	return ftrace_trace_probe_callback(tr, ops, hash, glob, cmd,
 					   param, enable);
 }
 
 static int
-ftrace_dump_callback(struct ftrace_hash *hash,
+ftrace_dump_callback(struct trace_array *tr, struct ftrace_hash *hash,
 			   char *glob, char *cmd, char *param, int enable)
 {
 	struct ftrace_probe_ops *ops;
 
+	if (!tr)
+		return -ENODEV;
+
 	ops = &dump_probe_ops;
 
 	/* Only dump once. */
-	return ftrace_trace_probe_callback(ops, hash, glob, cmd,
+	return ftrace_trace_probe_callback(tr, ops, hash, glob, cmd,
 					   "1", enable);
 }
 
 static int
-ftrace_cpudump_callback(struct ftrace_hash *hash,
+ftrace_cpudump_callback(struct trace_array *tr, struct ftrace_hash *hash,
 			   char *glob, char *cmd, char *param, int enable)
 {
 	struct ftrace_probe_ops *ops;
 
+	if (!tr)
+		return -ENODEV;
+
 	ops = &cpudump_probe_ops;
 
 	/* Only dump once. */
-	return ftrace_trace_probe_callback(ops, hash, glob, cmd,
+	return ftrace_trace_probe_callback(tr, ops, hash, glob, cmd,
 					   "1", enable);
 }
 
@@ -559,9 +1023,8 @@ static inline int init_func_cmd_traceon(void)
 }
 #endif /* CONFIG_DYNAMIC_FTRACE */
 
-static __init int init_function_trace(void)
+__init int init_function_trace(void)
 {
 	init_func_cmd_traceon();
 	return register_tracer(&function_trace);
 }
-core_initcall(init_function_trace);