7 files changed, 21 insertions, 15 deletions

diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile
index a3049da61985..1cad9318d217 100644
--- a/arch/x86/kernel/Makefile
+++ b/arch/x86/kernel/Makefile
@@ -14,12 +14,6 @@ CFLAGS_REMOVE_paravirt-spinlocks.o = -pg
 CFLAGS_REMOVE_ftrace.o = -pg
 endif
 
-ifdef CONFIG_FUNCTION_GRAPH_TRACER
-# Don't trace __switch_to() but let it for function tracer
-CFLAGS_REMOVE_process_32.o = -pg
-CFLAGS_REMOVE_process_64.o = -pg
-endif
-
 #
 # vsyscalls (which work on the user stack) should have
 # no stack-protector checks:
diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c
index 0a1302fe6d45..24c2276aa453 100644
--- a/arch/x86/kernel/process_32.c
+++ b/arch/x86/kernel/process_32.c
@@ -38,6 +38,7 @@
 #include <linux/percpu.h>
 #include <linux/prctl.h>
 #include <linux/dmi.h>
+#include <linux/ftrace.h>
 
 #include <asm/uaccess.h>
 #include <asm/pgtable.h>
@@ -548,7 +549,8 @@ __switch_to_xtra(struct task_struct *prev_p, struct task_struct *next_p,
  * the task-switch, and shows up in ret_from_fork in entry.S,
  * for example.
  */
-struct task_struct * __switch_to(struct task_struct *prev_p, struct task_struct *next_p)
+__notrace_funcgraph struct task_struct *
+__switch_to(struct task_struct *prev_p, struct task_struct *next_p)
 {
 	struct thread_struct *prev = &prev_p->thread,
 				 *next = &next_p->thread;
diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c
index c958120fb1b6..fbb321d53d34 100644
--- a/arch/x86/kernel/process_64.c
+++ b/arch/x86/kernel/process_64.c
@@ -39,6 +39,7 @@
 #include <linux/prctl.h>
 #include <linux/uaccess.h>
 #include <linux/io.h>
+#include <linux/ftrace.h>
 
 #include <asm/pgtable.h>
 #include <asm/system.h>
@@ -551,8 +552,9 @@ static inline void __switch_to_xtra(struct task_struct *prev_p,
  * - could test fs/gs bitsliced
  *
  * Kprobes not supported here. Set the probe on schedule instead.
+ * Function graph tracer not supported too.
  */
-struct task_struct *
+__notrace_funcgraph struct task_struct *
 __switch_to(struct task_struct *prev_p, struct task_struct *next_p)
 {
 	struct thread_struct *prev = &prev_p->thread;
diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h
index b9b4d0a22d10..449fa8e9e34f 100644
--- a/include/linux/ftrace.h
+++ b/include/linux/ftrace.h
@@ -369,6 +369,14 @@ struct ftrace_graph_ret {
 };
 
 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
+
+/*
+ * Sometimes we don't want to trace a function with the function
+ * graph tracer but we want them to keep traced by the usual function
+ * tracer if the function graph tracer is not configured.
+ */
+#define __notrace_funcgraph		notrace
+
 #define FTRACE_RETFUNC_DEPTH 50
 #define FTRACE_RETSTACK_ALLOC_SIZE 32
 /* Type of the callback handlers for tracing function graph*/
@@ -394,6 +402,9 @@ static inline int task_curr_ret_stack(struct task_struct *t)
 	return t->curr_ret_stack;
 }
 #else
+
+#define __notrace_funcgraph
+
 static inline void ftrace_graph_init_task(struct task_struct *t) { }
 static inline void ftrace_graph_exit_task(struct task_struct *t) { }
 
diff --git a/kernel/Makefile b/kernel/Makefile
index 703cf3b7389c..19fad003b19d 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -21,10 +21,6 @@ CFLAGS_REMOVE_cgroup-debug.o = -pg
 CFLAGS_REMOVE_sched_clock.o = -pg
 CFLAGS_REMOVE_sched.o = -pg
 endif
-ifdef CONFIG_FUNCTION_GRAPH_TRACER
-CFLAGS_REMOVE_extable.o = -pg # For __kernel_text_address()
-CFLAGS_REMOVE_module.o = -pg # For __module_text_address()
-endif
 
 obj-$(CONFIG_FREEZER) += freezer.o
 obj-$(CONFIG_PROFILING) += profile.o
diff --git a/kernel/extable.c b/kernel/extable.c
index a26cb2e17023..feb0317cf09a 100644
--- a/kernel/extable.c
+++ b/kernel/extable.c
@@ -17,6 +17,7 @@
 */
 #include <linux/module.h>
 #include <linux/init.h>
+#include <linux/ftrace.h>
 #include <asm/uaccess.h>
 #include <asm/sections.h>
 
@@ -40,7 +41,7 @@ const struct exception_table_entry *search_exception_tables(unsigned long addr)
 	return e;
 }
 
-int core_kernel_text(unsigned long addr)
+__notrace_funcgraph int core_kernel_text(unsigned long addr)
 {
 	if (addr >= (unsigned long)_stext &&
 	    addr <= (unsigned long)_etext)
@@ -53,7 +54,7 @@ int core_kernel_text(unsigned long addr)
 	return 0;
 }
 
-int __kernel_text_address(unsigned long addr)
+__notrace_funcgraph int __kernel_text_address(unsigned long addr)
 {
 	if (core_kernel_text(addr))
 		return 1;
diff --git a/kernel/module.c b/kernel/module.c
index 89bcf7c1327d..dd2a54155b54 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -2704,7 +2704,7 @@ int is_module_address(unsigned long addr)
 
 
 /* Is this a valid kernel address? */
-struct module *__module_text_address(unsigned long addr)
+__notrace_funcgraph struct module *__module_text_address(unsigned long addr)
 {
 	struct module *mod;