1 files changed, 369 insertions, 158 deletions

diff --git a/kernel/trace/trace_functions.c b/kernel/trace/trace_functions.c
index 16aee4d44e8..57f0ec962d2 100644
--- a/kernel/trace/trace_functions.c
+++ b/kernel/trace/trace_functions.c
@@ -7,115 +7,164 @@
  * Based on code from the latency_tracer, that is:
  *
  *  Copyright (C) 2004-2006 Ingo Molnar
- *  Copyright (C) 2004 William Lee Irwin III
+ *  Copyright (C) 2004 Nadia Yvette Chambers
  */
 #include <linux/ring_buffer.h>
 #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 pt_regs *pt_regs);
+static void
+function_stack_trace_call(unsigned long ip, unsigned long parent_ip,
+			  struct ftrace_ops *op, struct pt_regs *pt_regs);
+static struct tracer_flags func_flags;
+
+/* Our option */
+enum {
+	TRACE_FUNC_OPT_STACK	= 0x1,
+};
+
+static int allocate_ftrace_ops(struct trace_array *tr)
+{
+	struct ftrace_ops *ops;
+
+	ops = kzalloc(sizeof(*ops), GFP_KERNEL);
+	if (!ops)
+		return -ENOMEM;
 
-static struct trace_array	*func_trace;
+	/* Currently only the non stack verision is supported */
+	ops->func = function_trace_call;
+	ops->flags = FTRACE_OPS_FL_RECURSION_SAFE;
 
-static void tracing_start_function_trace(void);
-static void tracing_stop_function_trace(void);
+	tr->ops = ops;
+	ops->private = tr;
+	return 0;
+}
+
+
+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;
+
+	ret = allocate_ftrace_ops(tr);
+	if (ret)
+		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);
+	kfree(tr->ops);
+	tr->ops = NULL;
+}
 
 static int function_trace_init(struct trace_array *tr)
 {
-	func_trace = tr;
-	tr->cpu = get_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;
+
+	/* Currently only the global instance can do stack tracing */
+	if (tr->flags & TRACE_ARRAY_FL_GLOBAL &&
+	    func_flags.val & TRACE_FUNC_OPT_STACK)
+		func = function_stack_trace_call;
+	else
+		func = function_trace_call;
+
+	ftrace_init_array_ops(tr, func);
+
+	tr->trace_buffer.cpu = get_cpu();
 	put_cpu();
 
 	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);
+	tracing_reset_online_cpus(&tr->trace_buffer);
 }
 
 static void
-function_trace_call_preempt_only(unsigned long ip, unsigned long parent_ip)
+function_trace_call(unsigned long ip, unsigned long parent_ip,
+		    struct ftrace_ops *op, struct pt_regs *pt_regs)
 {
-	struct trace_array *tr = func_trace;
+	struct trace_array *tr = op->private;
 	struct trace_array_cpu *data;
 	unsigned long flags;
-	long disabled;
+	int bit;
 	int cpu;
 	int pc;
 
-	if (unlikely(!ftrace_function_enabled))
+	if (unlikely(!tr->function_enabled))
 		return;
 
 	pc = preempt_count();
 	preempt_disable_notrace();
-	local_save_flags(flags);
-	cpu = raw_smp_processor_id();
-	data = tr->data[cpu];
-	disabled = atomic_inc_return(&data->disabled);
-
-	if (likely(disabled == 1))
-		trace_function(tr, ip, parent_ip, flags, pc);
-
-	atomic_dec(&data->disabled);
-	preempt_enable_notrace();
-}
-
-static void
-function_trace_call(unsigned long ip, unsigned long parent_ip)
-{
-	struct trace_array *tr = func_trace;
-	struct trace_array_cpu *data;
-	unsigned long flags;
-	long disabled;
-	int cpu;
-	int pc;
-
-	if (unlikely(!ftrace_function_enabled))
-		return;
 
-	/*
-	 * Need to use raw, since this must be called before the
-	 * recursive protection is performed.
-	 */
-	local_irq_save(flags);
-	cpu = raw_smp_processor_id();
-	data = tr->data[cpu];
-	disabled = atomic_inc_return(&data->disabled);
+	bit = trace_test_and_set_recursion(TRACE_FTRACE_START, TRACE_FTRACE_MAX);
+	if (bit < 0)
+		goto out;
 
-	if (likely(disabled == 1)) {
-		pc = preempt_count();
+	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);
 
-	atomic_dec(&data->disabled);
-	local_irq_restore(flags);
+ out:
+	preempt_enable_notrace();
 }
 
 static void
-function_stack_trace_call(unsigned long ip, unsigned long parent_ip)
+function_stack_trace_call(unsigned long ip, unsigned long parent_ip,
+			  struct ftrace_ops *op, struct pt_regs *pt_regs)
 {
-	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;
 
-	if (unlikely(!ftrace_function_enabled))
+	if (unlikely(!tr->function_enabled))
 		return;
 
 	/*
@@ -124,7 +173,7 @@ function_stack_trace_call(unsigned long ip, unsigned long parent_ip)
 	 */
 	local_irq_save(flags);
 	cpu = raw_smp_processor_id();
-	data = tr->data[cpu];
+	data = per_cpu_ptr(tr->trace_buffer.data, cpu);
 	disabled = atomic_inc_return(&data->disabled);
 
 	if (likely(disabled == 1)) {
@@ -145,22 +194,6 @@ function_stack_trace_call(unsigned long ip, unsigned long parent_ip)
 	local_irq_restore(flags);
 }
 
-
-static struct ftrace_ops trace_ops __read_mostly =
-{
-	.func = function_trace_call,
-};
-
-static struct ftrace_ops trace_stack_ops __read_mostly =
-{
-	.func = function_stack_trace_call,
-};
-
-/* Our two options */
-enum {
-	TRACE_FUNC_OPT_STACK = 0x1,
-};
-
 static struct tracer_opt func_opts[] = {
 #ifdef CONFIG_STACKTRACE
 	{ TRACER_OPT(func_stack_trace, TRACE_FUNC_OPT_STACK) },
@@ -173,129 +206,159 @@ static struct tracer_flags func_flags = {
 	.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 (trace_flags & TRACE_ITER_PREEMPTONLY)
-		trace_ops.func = function_trace_call_preempt_only;
-	else
-		trace_ops.func = function_trace_call;
-
-	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 int
+func_set_flag(struct trace_array *tr, u32 old_flags, u32 bit, int set)
 {
-	if (bit == TRACE_FUNC_OPT_STACK) {
+	switch (bit) {
+	case TRACE_FUNC_OPT_STACK:
 		/* do nothing if already set */
 		if (!!set == !!(func_flags.val & TRACE_FUNC_OPT_STACK))
-			return 0;
+			break;
+
+		unregister_ftrace_function(tr->ops);
 
 		if (set) {
-			unregister_ftrace_function(&trace_ops);
-			register_ftrace_function(&trace_stack_ops);
+			tr->ops->func = function_stack_trace_call;
+			register_ftrace_function(tr->ops);
 		} else {
-			unregister_ftrace_function(&trace_stack_ops);
-			register_ftrace_function(&trace_ops);
+			tr->ops->func = function_trace_call;
+			register_ftrace_function(tr->ops);
 		}
 
-		return 0;
+		break;
+	default:
+		return -EINVAL;
 	}
 
-	return -EINVAL;
+	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,
 	.set_flag	= func_set_flag,
+	.allow_instances = true,
 #ifdef CONFIG_FTRACE_SELFTEST
 	.selftest	= trace_selftest_startup_function,
 #endif
 };
 
 #ifdef CONFIG_DYNAMIC_FTRACE
-static void
-ftrace_traceon(unsigned long ip, unsigned long parent_ip, void **data)
+static int update_count(void **data)
 {
-	long *count = (long *)data;
-
-	if (tracing_is_on())
-		return;
+	unsigned long *count = (long *)data;
 
 	if (!*count)
-		return;
+		return 0;
 
 	if (*count != -1)
 		(*count)--;
 
-	tracing_on();
+	return 1;
 }
 
 static void
-ftrace_traceoff(unsigned long ip, unsigned long parent_ip, void **data)
+ftrace_traceon_count(unsigned long ip, unsigned long parent_ip, void **data)
 {
-	long *count = (long *)data;
+	if (tracing_is_on())
+		return;
 
+	if (update_count(data))
+		tracing_on();
+}
+
+static void
+ftrace_traceoff_count(unsigned long ip, unsigned long parent_ip, void **data)
+{
 	if (!tracing_is_on())
 		return;
 
-	if (!*count)
+	if (update_count(data))
+		tracing_off();
+}
+
+static void
+ftrace_traceon(unsigned long ip, unsigned long parent_ip, void **data)
+{
+	if (tracing_is_on())
 		return;
 
-	if (*count != -1)
-		(*count)--;
+	tracing_on();
+}
+
+static void
+ftrace_traceoff(unsigned long ip, unsigned long parent_ip, void **data)
+{
+	if (!tracing_is_on())
+		return;
 
 	tracing_off();
 }
 
-static int
-ftrace_trace_onoff_print(struct seq_file *m, unsigned long ip,
-			 struct ftrace_probe_ops *ops, void *data);
+/*
+ * Skip 4:
+ *   ftrace_stacktrace()
+ *   function_trace_probe_call()
+ *   ftrace_ops_list_func()
+ *   ftrace_call()
+ */
+#define STACK_SKIP 4
 
-static struct ftrace_probe_ops traceon_probe_ops = {
-	.func			= ftrace_traceon,
-	.print			= ftrace_trace_onoff_print,
-};
+static void
+ftrace_stacktrace(unsigned long ip, unsigned long parent_ip, void **data)
+{
+	trace_dump_stack(STACK_SKIP);
+}
 
-static struct ftrace_probe_ops traceoff_probe_ops = {
-	.func			= ftrace_traceoff,
-	.print			= ftrace_trace_onoff_print,
-};
+static void
+ftrace_stacktrace_count(unsigned long ip, unsigned long parent_ip, void **data)
+{
+	if (!tracing_is_on())
+		return;
+
+	if (update_count(data))
+		trace_dump_stack(STACK_SKIP);
+}
+
+static void
+ftrace_dump_probe(unsigned long ip, unsigned long parent_ip, void **data)
+{
+	if (update_count(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)
+{
+	if (update_count(data))
+		ftrace_dump(DUMP_ORIG);
+}
 
 static int
-ftrace_trace_onoff_print(struct seq_file *m, unsigned long ip,
-			 struct ftrace_probe_ops *ops, void *data)
+ftrace_probe_print(const char *name, struct seq_file *m,
+		   unsigned long ip, void *data)
 {
 	long count = (long)data;
 
-	seq_printf(m, "%ps:", (void *)ip);
-
-	if (ops == &traceon_probe_ops)
-		seq_printf(m, "traceon");
-	else
-		seq_printf(m, "traceoff");
+	seq_printf(m, "%ps:%s", (void *)ip, name);
 
 	if (count == -1)
 		seq_printf(m, ":unlimited\n");
@@ -306,25 +369,85 @@ ftrace_trace_onoff_print(struct seq_file *m, unsigned long ip,
 }
 
 static int
-ftrace_trace_onoff_unreg(char *glob, char *cmd, char *param)
+ftrace_traceon_print(struct seq_file *m, unsigned long ip,
+			 struct ftrace_probe_ops *ops, void *data)
 {
-	struct ftrace_probe_ops *ops;
+	return ftrace_probe_print("traceon", m, ip, data);
+}
 
-	/* we register both traceon and traceoff to this callback */
-	if (strcmp(cmd, "traceon") == 0)
-		ops = &traceon_probe_ops;
-	else
-		ops = &traceoff_probe_ops;
+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);
+}
 
-	unregister_ftrace_function_probe_func(glob, ops);
+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 0;
+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);
 }
 
 static int
-ftrace_trace_onoff_callback(char *glob, char *cmd, char *param, int enable)
+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);
+}
+
+static struct ftrace_probe_ops traceon_count_probe_ops = {
+	.func			= ftrace_traceon_count,
+	.print			= ftrace_traceon_print,
+};
+
+static struct ftrace_probe_ops traceoff_count_probe_ops = {
+	.func			= ftrace_traceoff_count,
+	.print			= ftrace_traceoff_print,
+};
+
+static struct ftrace_probe_ops stacktrace_count_probe_ops = {
+	.func			= ftrace_stacktrace_count,
+	.print			= ftrace_stacktrace_print,
+};
+
+static struct ftrace_probe_ops dump_probe_ops = {
+	.func			= ftrace_dump_probe,
+	.print			= ftrace_dump_print,
+};
+
+static struct ftrace_probe_ops cpudump_probe_ops = {
+	.func			= ftrace_cpudump_probe,
+	.print			= ftrace_cpudump_print,
+};
+
+static struct ftrace_probe_ops traceon_probe_ops = {
+	.func			= ftrace_traceon,
+	.print			= ftrace_traceon_print,
+};
+
+static struct ftrace_probe_ops traceoff_probe_ops = {
+	.func			= ftrace_traceoff,
+	.print			= ftrace_traceoff_print,
+};
+
+static struct ftrace_probe_ops stacktrace_probe_ops = {
+	.func			= ftrace_stacktrace,
+	.print			= ftrace_stacktrace_print,
+};
+
+static int
+ftrace_trace_probe_callback(struct ftrace_probe_ops *ops,
+			    struct ftrace_hash *hash, char *glob,
+			    char *cmd, char *param, int enable)
 {
-	struct ftrace_probe_ops *ops;
 	void *count = (void *)-1;
 	char *number;
 	int ret;
@@ -333,14 +456,10 @@ ftrace_trace_onoff_callback(char *glob, char *cmd, char *param, int enable)
 	if (!enable)
 		return -EINVAL;
 
-	if (glob[0] == '!')
-		return ftrace_trace_onoff_unreg(glob+1, cmd, param);
-
-	/* we register both traceon and traceoff to this callback */
-	if (strcmp(cmd, "traceon") == 0)
-		ops = &traceon_probe_ops;
-	else
-		ops = &traceoff_probe_ops;
+	if (glob[0] == '!') {
+		unregister_ftrace_function_probe_func(glob+1, ops);
+		return 0;
+	}
 
 	if (!param)
 		goto out_reg;
@@ -354,7 +473,7 @@ ftrace_trace_onoff_callback(char *glob, char *cmd, char *param, int enable)
 	 * We use the callback data field (which is a pointer)
 	 * as our counter.
 	 */
-	ret = strict_strtoul(number, 0, (unsigned long *)&count);
+	ret = kstrtoul(number, 0, (unsigned long *)&count);
 	if (ret)
 		return ret;
 
@@ -364,6 +483,60 @@ ftrace_trace_onoff_callback(char *glob, char *cmd, char *param, int enable)
 	return ret < 0 ? ret : 0;
 }
 
+static int
+ftrace_trace_onoff_callback(struct ftrace_hash *hash,
+			    char *glob, char *cmd, char *param, int enable)
+{
+	struct ftrace_probe_ops *ops;
+
+	/* 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,
+					   param, enable);
+}
+
+static int
+ftrace_stacktrace_callback(struct ftrace_hash *hash,
+			   char *glob, char *cmd, char *param, int enable)
+{
+	struct ftrace_probe_ops *ops;
+
+	ops = param ? &stacktrace_count_probe_ops : &stacktrace_probe_ops;
+
+	return ftrace_trace_probe_callback(ops, hash, glob, cmd,
+					   param, enable);
+}
+
+static int
+ftrace_dump_callback(struct ftrace_hash *hash,
+			   char *glob, char *cmd, char *param, int enable)
+{
+	struct ftrace_probe_ops *ops;
+
+	ops = &dump_probe_ops;
+
+	/* Only dump once. */
+	return ftrace_trace_probe_callback(ops, hash, glob, cmd,
+					   "1", enable);
+}
+
+static int
+ftrace_cpudump_callback(struct ftrace_hash *hash,
+			   char *glob, char *cmd, char *param, int enable)
+{
+	struct ftrace_probe_ops *ops;
+
+	ops = &cpudump_probe_ops;
+
+	/* Only dump once. */
+	return ftrace_trace_probe_callback(ops, hash, glob, cmd,
+					   "1", enable);
+}
+
 static struct ftrace_func_command ftrace_traceon_cmd = {
 	.name			= "traceon",
 	.func			= ftrace_trace_onoff_callback,
@@ -374,6 +547,21 @@ static struct ftrace_func_command ftrace_traceoff_cmd = {
 	.func			= ftrace_trace_onoff_callback,
 };
 
+static struct ftrace_func_command ftrace_stacktrace_cmd = {
+	.name			= "stacktrace",
+	.func			= ftrace_stacktrace_callback,
+};
+
+static struct ftrace_func_command ftrace_dump_cmd = {
+	.name			= "dump",
+	.func			= ftrace_dump_callback,
+};
+
+static struct ftrace_func_command ftrace_cpudump_cmd = {
+	.name			= "cpudump",
+	.func			= ftrace_cpudump_callback,
+};
+
 static int __init init_func_cmd_traceon(void)
 {
 	int ret;
@@ -384,7 +572,31 @@ static int __init init_func_cmd_traceon(void)
 
 	ret = register_ftrace_command(&ftrace_traceon_cmd);
 	if (ret)
-		unregister_ftrace_command(&ftrace_traceoff_cmd);
+		goto out_free_traceoff;
+
+	ret = register_ftrace_command(&ftrace_stacktrace_cmd);
+	if (ret)
+		goto out_free_traceon;
+
+	ret = register_ftrace_command(&ftrace_dump_cmd);
+	if (ret)
+		goto out_free_stacktrace;
+
+	ret = register_ftrace_command(&ftrace_cpudump_cmd);
+	if (ret)
+		goto out_free_dump;
+
+	return 0;
+
+ out_free_dump:
+	unregister_ftrace_command(&ftrace_dump_cmd);
+ out_free_stacktrace:
+	unregister_ftrace_command(&ftrace_stacktrace_cmd);
+ out_free_traceon:
+	unregister_ftrace_command(&ftrace_traceon_cmd);
+ out_free_traceoff:
+	unregister_ftrace_command(&ftrace_traceoff_cmd);
+
 	return ret;
 }
 #else
@@ -399,5 +611,4 @@ static __init int init_function_trace(void)
 	init_func_cmd_traceon();
 	return register_tracer(&function_trace);
 }
-device_initcall(init_function_trace);
-
+core_initcall(init_function_trace);