tracing/function-return-tracer: change the name into function-graph-t…

…racer

Impact: cleanup

This patch changes the name of the "return function tracer" into
function-graph-tracer which is a more suitable name for a tracing
which makes one able to retrieve the ordered call stack during
the code flow.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

arch/x86/Kconfig

@@ -29,7 +29,7 @@ config X86
 	select HAVE_FTRACE_MCOUNT_RECORD
 	select HAVE_DYNAMIC_FTRACE
 	select HAVE_FUNCTION_TRACER
-	select HAVE_FUNCTION_RET_TRACER if X86_32
+	select HAVE_FUNCTION_GRAPH_TRACER if X86_32
 	select HAVE_FUNCTION_TRACE_MCOUNT_TEST
 	select HAVE_KVM if ((X86_32 && !X86_VOYAGER && !X86_VISWS && !X86_NUMAQ) || X86_64)
 	select HAVE_ARCH_KGDB if !X86_VOYAGER

arch/x86/include/asm/ftrace.h

@@ -28,7 +28,7 @@ struct dyn_arch_ftrace {
 #endif /* __ASSEMBLY__ */
 #endif /* CONFIG_FUNCTION_TRACER */
 
-#ifdef CONFIG_FUNCTION_RET_TRACER
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
 
 #ifndef __ASSEMBLY__
 
@@ -51,6 +51,6 @@ struct ftrace_ret_stack {
 extern void return_to_handler(void);
 
 #endif /* __ASSEMBLY__ */
-#endif /* CONFIG_FUNCTION_RET_TRACER */
+#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
 
 #endif /* _ASM_X86_FTRACE_H */

arch/x86/kernel/Makefile

@@ -14,7 +14,7 @@ CFLAGS_REMOVE_paravirt-spinlocks.o = -pg
 CFLAGS_REMOVE_ftrace.o = -pg
 endif
 
-ifdef CONFIG_FUNCTION_RET_TRACER
+ifdef CONFIG_FUNCTION_GRAPH_TRACER
 # Don't trace __switch_to() but let it for function tracer
 CFLAGS_REMOVE_process_32.o = -pg
 endif
@@ -70,7 +70,7 @@ obj-$(CONFIG_X86_LOCAL_APIC)	+= apic.o nmi.o
 obj-$(CONFIG_X86_IO_APIC)	+= io_apic.o
 obj-$(CONFIG_X86_REBOOTFIXUPS)	+= reboot_fixups_32.o
 obj-$(CONFIG_DYNAMIC_FTRACE)	+= ftrace.o
-obj-$(CONFIG_FUNCTION_RET_TRACER)	+= ftrace.o
+obj-$(CONFIG_FUNCTION_GRAPH_TRACER)	+= ftrace.o
 obj-$(CONFIG_KEXEC)		+= machine_kexec_$(BITS).o
 obj-$(CONFIG_KEXEC)		+= relocate_kernel_$(BITS).o crash.o
 obj-$(CONFIG_CRASH_DUMP)	+= crash_dump_$(BITS).o

arch/x86/kernel/entry_32.S

@@ -1188,9 +1188,9 @@ ENTRY(mcount)
 
 	cmpl $ftrace_stub, ftrace_trace_function
 	jnz trace
-#ifdef CONFIG_FUNCTION_RET_TRACER
-	cmpl $ftrace_stub, ftrace_function_return
-	jnz ftrace_return_caller
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+	cmpl $ftrace_stub, ftrace_graph_function
+	jnz ftrace_graph_caller
 #endif
 .globl ftrace_stub
 ftrace_stub:
@@ -1215,8 +1215,8 @@ END(mcount)
 #endif /* CONFIG_DYNAMIC_FTRACE */
 #endif /* CONFIG_FUNCTION_TRACER */
 
-#ifdef CONFIG_FUNCTION_RET_TRACER
-ENTRY(ftrace_return_caller)
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+ENTRY(ftrace_graph_caller)
 	cmpl $0, function_trace_stop
 	jne ftrace_stub
 
@@ -1230,7 +1230,7 @@ ENTRY(ftrace_return_caller)
 	popl %ecx
 	popl %eax
 	ret
-END(ftrace_return_caller)
+END(ftrace_graph_caller)
 
 .globl return_to_handler
 return_to_handler:

arch/x86/kernel/ftrace.c

@@ -323,7 +323,7 @@ int __init ftrace_dyn_arch_init(void *data)
 }
 #endif
 
-#ifdef CONFIG_FUNCTION_RET_TRACER
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
 
 #ifndef CONFIG_DYNAMIC_FTRACE
 
@@ -389,11 +389,11 @@ static void pop_return_trace(unsigned long *ret, unsigned long long *time,
  */
 unsigned long ftrace_return_to_handler(void)
 {
-	struct ftrace_retfunc trace;
+	struct ftrace_graph_ret trace;
 	pop_return_trace(&trace.ret, &trace.calltime, &trace.func,
 			&trace.overrun);
 	trace.rettime = cpu_clock(raw_smp_processor_id());
-	ftrace_function_return(&trace);
+	ftrace_graph_function(&trace);
 
 	return trace.ret;
 }
@@ -440,12 +440,12 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr)
 	);
 
 	if (WARN_ON(faulted)) {
-		unregister_ftrace_return();
+		unregister_ftrace_graph();
 		return;
 	}
 
 	if (WARN_ON(!__kernel_text_address(old))) {
-		unregister_ftrace_return();
+		unregister_ftrace_graph();
 		*parent = old;
 		return;
 	}
@@ -456,4 +456,4 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr)
 		*parent = old;
 }
 
-#endif /* CONFIG_FUNCTION_RET_TRACER */
+#endif /* CONFIG_FUNCTION_GRAPH_TRACER */

include/linux/ftrace.h

@@ -115,8 +115,8 @@ extern int ftrace_update_ftrace_func(ftrace_func_t func);
 extern void ftrace_caller(void);
 extern void ftrace_call(void);
 extern void mcount_call(void);
-#ifdef CONFIG_FUNCTION_RET_TRACER
-extern void ftrace_return_caller(void);
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+extern void ftrace_graph_caller(void);
 #endif
 
 /**
@@ -315,7 +315,7 @@ ftrace_init_module(struct module *mod,
 /*
  * Structure that defines a return function trace.
  */
-struct ftrace_retfunc {
+struct ftrace_graph_ret {
 	unsigned long ret; /* Return address */
 	unsigned long func; /* Current function */
 	unsigned long long calltime;
@@ -324,22 +324,22 @@ struct ftrace_retfunc {
 	unsigned long overrun;
 };
 
-#ifdef CONFIG_FUNCTION_RET_TRACER
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
 #define FTRACE_RETFUNC_DEPTH 50
 #define FTRACE_RETSTACK_ALLOC_SIZE 32
 /* Type of a callback handler of tracing return function */
-typedef void (*trace_function_return_t)(struct ftrace_retfunc *);
+typedef void (*trace_function_graph_t)(struct ftrace_graph_ret *);
 
-extern int register_ftrace_return(trace_function_return_t func);
+extern int register_ftrace_graph(trace_function_graph_t func);
 /* The current handler in use */
-extern trace_function_return_t ftrace_function_return;
-extern void unregister_ftrace_return(void);
+extern trace_function_graph_t ftrace_graph_function;
+extern void unregister_ftrace_graph(void);
 
-extern void ftrace_retfunc_init_task(struct task_struct *t);
-extern void ftrace_retfunc_exit_task(struct task_struct *t);
+extern void ftrace_graph_init_task(struct task_struct *t);
+extern void ftrace_graph_exit_task(struct task_struct *t);
 #else
-static inline void ftrace_retfunc_init_task(struct task_struct *t) { }
-static inline void ftrace_retfunc_exit_task(struct task_struct *t) { }
+static inline void ftrace_graph_init_task(struct task_struct *t) { }
+static inline void ftrace_graph_exit_task(struct task_struct *t) { }
 #endif
 
 #endif /* _LINUX_FTRACE_H */

include/linux/ftrace_irq.h

@@ -2,7 +2,7 @@
 #define _LINUX_FTRACE_IRQ_H
 
 
-#if defined(CONFIG_DYNAMIC_FTRACE) || defined(CONFIG_FUNCTION_RET_TRACER)
+#if defined(CONFIG_DYNAMIC_FTRACE) || defined(CONFIG_FUNCTION_GRAPH_TRACER)
 extern void ftrace_nmi_enter(void);
 extern void ftrace_nmi_exit(void);
 #else

include/linux/sched.h

@@ -1365,7 +1365,7 @@ struct task_struct {
 	unsigned long default_timer_slack_ns;
 
 	struct list_head	*scm_work_list;
-#ifdef CONFIG_FUNCTION_RET_TRACER
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
 	/* Index of current stored adress in ret_stack */
 	int curr_ret_stack;
 	/* Stack of return addresses for return function tracing */

kernel/Makefile

@@ -21,7 +21,7 @@ CFLAGS_REMOVE_cgroup-debug.o = -pg
 CFLAGS_REMOVE_sched_clock.o = -pg
 CFLAGS_REMOVE_sched.o = -pg
 endif
-ifdef CONFIG_FUNCTION_RET_TRACER
+ifdef CONFIG_FUNCTION_GRAPH_TRACER
 CFLAGS_REMOVE_extable.o = -pg # For __kernel_text_address()
 CFLAGS_REMOVE_module.o = -pg # For __module_text_address()
 endif

kernel/fork.c

@@ -140,7 +140,7 @@ void free_task(struct task_struct *tsk)
 	prop_local_destroy_single(&tsk->dirties);
 	free_thread_info(tsk->stack);
 	rt_mutex_debug_task_free(tsk);
-	ftrace_retfunc_exit_task(tsk);
+	ftrace_graph_exit_task(tsk);
 	free_task_struct(tsk);
 }
 EXPORT_SYMBOL(free_task);
@@ -1271,7 +1271,7 @@ static struct task_struct *copy_process(unsigned long clone_flags,
 	total_forks++;
 	spin_unlock(&current->sighand->siglock);
 	write_unlock_irq(&tasklist_lock);
-	ftrace_retfunc_init_task(p);
+	ftrace_graph_init_task(p);
 	proc_fork_connector(p);
 	cgroup_post_fork(p);
 	return p;

kernel/sched.c

@@ -5901,7 +5901,7 @@ void __cpuinit init_idle(struct task_struct *idle, int cpu)
 	 * The idle tasks have their own, simple scheduling class:
 	 */
 	idle->sched_class = &idle_sched_class;
-	ftrace_retfunc_init_task(idle);
+	ftrace_graph_init_task(idle);
 }
 
 /*

kernel/trace/Kconfig

@@ -12,7 +12,7 @@ config NOP_TRACER
 config HAVE_FUNCTION_TRACER
 	bool
 
-config HAVE_FUNCTION_RET_TRACER
+config HAVE_FUNCTION_GRAPH_TRACER
 	bool
 
 config HAVE_FUNCTION_TRACE_MCOUNT_TEST
@@ -63,15 +63,18 @@ config FUNCTION_TRACER
 	  (the bootup default), then the overhead of the instructions is very
 	  small and not measurable even in micro-benchmarks.
 
-config FUNCTION_RET_TRACER
-	bool "Kernel Function return Tracer"
-	depends on HAVE_FUNCTION_RET_TRACER
+config FUNCTION_GRAPH_TRACER
+	bool "Kernel Function Graph Tracer"
+	depends on HAVE_FUNCTION_GRAPH_TRACER
 	depends on FUNCTION_TRACER
 	help
-	  Enable the kernel to trace a function at its return.
-	  It's first purpose is to trace the duration of functions.
-	  This is done by setting the current return address on the thread
-	  info structure of the current task.
+	  Enable the kernel to trace a function at both its return
+	  and its entry.
+	  It's first purpose is to trace the duration of functions and
+	  draw a call graph for each thread with some informations like
+	  the return value.
+	  This is done by setting the current return address on the current
+	  task structure into a stack of calls.
 
 config IRQSOFF_TRACER
 	bool "Interrupts-off Latency Tracer"

kernel/trace/Makefile

@@ -29,7 +29,7 @@ obj-$(CONFIG_NOP_TRACER) += trace_nop.o
 obj-$(CONFIG_STACK_TRACER) += trace_stack.o
 obj-$(CONFIG_MMIOTRACE) += trace_mmiotrace.o
 obj-$(CONFIG_BOOT_TRACER) += trace_boot.o
-obj-$(CONFIG_FUNCTION_RET_TRACER) += trace_functions_return.o
+obj-$(CONFIG_FUNCTION_GRAPH_TRACER) += trace_functions_graph.o
 obj-$(CONFIG_TRACE_BRANCH_PROFILING) += trace_branch.o
 obj-$(CONFIG_BTS_TRACER) += trace_bts.o
 

kernel/trace/ftrace.c

@@ -395,11 +395,11 @@ __ftrace_replace_code(struct dyn_ftrace *rec, int enable)
 	unsigned long ip, fl;
 	unsigned long ftrace_addr;
 
-#ifdef CONFIG_FUNCTION_RET_TRACER
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
 	if (ftrace_tracing_type == FTRACE_TYPE_ENTER)
 		ftrace_addr = (unsigned long)ftrace_caller;
 	else
-		ftrace_addr = (unsigned long)ftrace_return_caller;
+		ftrace_addr = (unsigned long)ftrace_graph_caller;
 #else
 	ftrace_addr = (unsigned long)ftrace_caller;
 #endif
@@ -1496,13 +1496,13 @@ ftrace_enable_sysctl(struct ctl_table *table, int write,
 	return ret;
 }
 
-#ifdef CONFIG_FUNCTION_RET_TRACER
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
 
 static atomic_t ftrace_retfunc_active;
 
 /* The callback that hooks the return of a function */
-trace_function_return_t ftrace_function_return =
-			(trace_function_return_t)ftrace_stub;
+trace_function_graph_t ftrace_graph_function =
+			(trace_function_graph_t)ftrace_stub;
 
 
 /* Try to assign a return stack array on FTRACE_RETSTACK_ALLOC_SIZE tasks. */
@@ -1549,7 +1549,7 @@ static int alloc_retstack_tasklist(struct ftrace_ret_stack **ret_stack_list)
 }
 
 /* Allocate a return stack for each task */
-static int start_return_tracing(void)
+static int start_graph_tracing(void)
 {
 	struct ftrace_ret_stack **ret_stack_list;
 	int ret;
@@ -1569,7 +1569,7 @@ static int start_return_tracing(void)
 	return ret;
 }
 
-int register_ftrace_return(trace_function_return_t func)
+int register_ftrace_graph(trace_function_graph_t func)
 {
 	int ret = 0;
 
@@ -1584,26 +1584,26 @@ int register_ftrace_return(trace_function_return_t func)
 		goto out;
 	}
 	atomic_inc(&ftrace_retfunc_active);
-	ret = start_return_tracing();
+	ret = start_graph_tracing();
 	if (ret) {
 		atomic_dec(&ftrace_retfunc_active);
 		goto out;
 	}
 	ftrace_tracing_type = FTRACE_TYPE_RETURN;
-	ftrace_function_return = func;
+	ftrace_graph_function = func;
 	ftrace_startup();
 
 out:
 	mutex_unlock(&ftrace_sysctl_lock);
 	return ret;
 }
 
-void unregister_ftrace_return(void)
+void unregister_ftrace_graph(void)
 {
 	mutex_lock(&ftrace_sysctl_lock);
 
 	atomic_dec(&ftrace_retfunc_active);
-	ftrace_function_return = (trace_function_return_t)ftrace_stub;
+	ftrace_graph_function = (trace_function_graph_t)ftrace_stub;
 	ftrace_shutdown();
 	/* Restore normal tracing type */
 	ftrace_tracing_type = FTRACE_TYPE_ENTER;
@@ -1612,7 +1612,7 @@ void unregister_ftrace_return(void)
 }
 
 /* Allocate a return stack for newly created task */
-void ftrace_retfunc_init_task(struct task_struct *t)
+void ftrace_graph_init_task(struct task_struct *t)
 {
 	if (atomic_read(&ftrace_retfunc_active)) {
 		t->ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH
@@ -1626,7 +1626,7 @@ void ftrace_retfunc_init_task(struct task_struct *t)
 		t->ret_stack = NULL;
 }
 
-void ftrace_retfunc_exit_task(struct task_struct *t)
+void ftrace_graph_exit_task(struct task_struct *t)
 {
 	struct ftrace_ret_stack	*ret_stack = t->ret_stack;