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

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>

9 files changed, 142 insertions, 41 deletions

diff --git a/kernel/Makefile b/kernel/Makefile
index 03a45e7e87b7..703cf3b7389c 100644
--- a/kernel/Makefile
+++ b/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
diff --git a/kernel/fork.c b/kernel/fork.c
index d6e1a3205f62..5f82a999c032 100644
--- a/kernel/fork.c
+++ b/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;
diff --git a/kernel/sched.c b/kernel/sched.c
index 388d9db044ab..52490bf6b884 100644
--- a/kernel/sched.c
+++ b/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);
 }
 
 /*
diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig
index 620feadff67a..eb9b901e0777 100644
--- a/kernel/trace/Kconfig
+++ b/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"
diff --git a/kernel/trace/Makefile b/kernel/trace/Makefile
index cef4bcb4e822..08c5fe6ddc09 100644
--- a/kernel/trace/Makefile
+++ b/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
 
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 53042f118f23..9e19976af727 100644
--- a/kernel/trace/ftrace.c
+++ b/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 @@ free:
 }
 
 /* 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;
 
@@ -1584,13 +1584,13 @@ 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;