---

yaml
---
r: 121177
b: refs/heads/master
c: cbe2f5a
h: refs/heads/master
i:
  121175: c87ab2e
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 65afa5e603d507014580ead016ec887b49e1afa6
+refs/heads/master: cbe2f5a6e84eebb98ab42fc5e58c3cd5b7767349

trunk/arch/x86/include/asm/ftrace.h

@@ -29,6 +29,7 @@ struct dyn_arch_ftrace {
 #endif /* CONFIG_FUNCTION_TRACER */
 
 #ifdef CONFIG_FUNCTION_RET_TRACER
+#define FTRACE_RET_STACK_SIZE 20
 
 #ifndef __ASSEMBLY__
 

trunk/arch/x86/include/asm/thread_info.h

@@ -40,8 +40,36 @@ struct thread_info {
 						*/
 	__u8			supervisor_stack[0];
 #endif
+
+#ifdef CONFIG_FUNCTION_RET_TRACER
+	/* Index of current stored adress in ret_stack */
+	int		curr_ret_stack;
+	/* Stack of return addresses for return function tracing */
+	struct ftrace_ret_stack	ret_stack[FTRACE_RET_STACK_SIZE];
+	/*
+	 * Number of functions that haven't been traced
+	 * because of depth overrun.
+	 */
+	atomic_t	trace_overrun;
+#endif
 };
 
+#ifdef CONFIG_FUNCTION_RET_TRACER
+#define INIT_THREAD_INFO(tsk)			\
+{						\
+	.task		= &tsk,			\
+	.exec_domain	= &default_exec_domain,	\
+	.flags		= 0,			\
+	.cpu		= 0,			\
+	.preempt_count	= 1,			\
+	.addr_limit	= KERNEL_DS,		\
+	.restart_block = {			\
+		.fn = do_no_restart_syscall,	\
+	},					\
+	.curr_ret_stack = -1,\
+	.trace_overrun	= ATOMIC_INIT(0)	\
+}
+#else
 #define INIT_THREAD_INFO(tsk)			\
 {						\
 	.task		= &tsk,			\
@@ -54,6 +82,7 @@ struct thread_info {
 		.fn = do_no_restart_syscall,	\
 	},					\
 }
+#endif
 
 #define init_thread_info	(init_thread_union.thread_info)
 #define init_stack		(init_thread_union.stack)

trunk/arch/x86/kernel/ftrace.c

@@ -350,21 +350,19 @@ static int push_return_trace(unsigned long ret, unsigned long long time,
 				unsigned long func)
 {
 	int index;
-
-	if (!current->ret_stack)
-		return -EBUSY;
+	struct thread_info *ti = current_thread_info();
 
 	/* The return trace stack is full */
-	if (current->curr_ret_stack == FTRACE_RETFUNC_DEPTH - 1) {
-		atomic_inc(&current->trace_overrun);
+	if (ti->curr_ret_stack == FTRACE_RET_STACK_SIZE - 1) {
+		atomic_inc(&ti->trace_overrun);
 		return -EBUSY;
 	}
 
-	index = ++current->curr_ret_stack;
+	index = ++ti->curr_ret_stack;
 	barrier();
-	current->ret_stack[index].ret = ret;
-	current->ret_stack[index].func = func;
-	current->ret_stack[index].calltime = time;
+	ti->ret_stack[index].ret = ret;
+	ti->ret_stack[index].func = func;
+	ti->ret_stack[index].calltime = time;
 
 	return 0;
 }
@@ -375,12 +373,13 @@ static void pop_return_trace(unsigned long *ret, unsigned long long *time,
 {
 	int index;
 
-	index = current->curr_ret_stack;
-	*ret = current->ret_stack[index].ret;
-	*func = current->ret_stack[index].func;
-	*time = current->ret_stack[index].calltime;
-	*overrun = atomic_read(&current->trace_overrun);
-	current->curr_ret_stack--;
+	struct thread_info *ti = current_thread_info();
+	index = ti->curr_ret_stack;
+	*ret = ti->ret_stack[index].ret;
+	*func = ti->ret_stack[index].func;
+	*time = ti->ret_stack[index].calltime;
+	*overrun = atomic_read(&ti->trace_overrun);
+	ti->curr_ret_stack--;
 }
 
 /*

trunk/include/linux/ftrace.h

@@ -323,21 +323,13 @@ struct ftrace_retfunc {
 };
 
 #ifdef CONFIG_FUNCTION_RET_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 *);
 
 extern int register_ftrace_return(trace_function_return_t func);
 /* The current handler in use */
 extern trace_function_return_t ftrace_function_return;
 extern void unregister_ftrace_return(void);
-
-extern void ftrace_retfunc_init_task(struct task_struct *t);
-extern void ftrace_retfunc_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) { }
 #endif
 
 #endif /* _LINUX_FTRACE_H */

trunk/include/linux/sched.h

@@ -1352,17 +1352,6 @@ struct task_struct {
 	unsigned long default_timer_slack_ns;
 
 	struct list_head	*scm_work_list;
-#ifdef CONFIG_FUNCTION_RET_TRACER
-	/* Index of current stored adress in ret_stack */
-	int curr_ret_stack;
-	/* Stack of return addresses for return function tracing */
-	struct ftrace_ret_stack	*ret_stack;
-	/*
-	 * Number of functions that haven't been traced
-	 * because of depth overrun.
-	 */
-	atomic_t trace_overrun;
-#endif
 };
 
 /*
@@ -2017,6 +2006,18 @@ static inline void setup_thread_stack(struct task_struct *p, struct task_struct
 {
 	*task_thread_info(p) = *task_thread_info(org);
 	task_thread_info(p)->task = p;
+
+#ifdef CONFIG_FUNCTION_RET_TRACER
+	/*
+	 * When fork() creates a child process, this function is called.
+	 * But the child task may not inherit the return adresses traced
+	 * by the return function tracer because it will directly execute
+	 * in userspace and will not return to kernel functions its parent
+	 * used.
+	 */
+	task_thread_info(p)->curr_ret_stack = -1;
+	atomic_set(&task_thread_info(p)->trace_overrun, 0);
+#endif
 }
 
 static inline unsigned long *end_of_stack(struct task_struct *p)

trunk/kernel/exit.c

@@ -1127,6 +1127,7 @@ NORET_TYPE void do_exit(long code)
 	preempt_disable();
 	/* causes final put_task_struct in finish_task_switch(). */
 	tsk->state = TASK_DEAD;
+
 	schedule();
 	BUG();
 	/* Avoid "noreturn function does return".  */

trunk/kernel/fork.c

@@ -47,7 +47,6 @@
 #include <linux/mount.h>
 #include <linux/audit.h>
 #include <linux/memcontrol.h>
-#include <linux/ftrace.h>
 #include <linux/profile.h>
 #include <linux/rmap.h>
 #include <linux/acct.h>
@@ -140,7 +139,6 @@ 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);
 	free_task_struct(tsk);
 }
 EXPORT_SYMBOL(free_task);
@@ -1271,7 +1269,6 @@ 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);
 	proc_fork_connector(p);
 	cgroup_post_fork(p);
 	return p;

trunk/kernel/power/disk.c

@@ -22,7 +22,6 @@
 #include <linux/console.h>
 #include <linux/cpu.h>
 #include <linux/freezer.h>
-#include <linux/ftrace.h>
 
 #include "power.h"
 
@@ -257,7 +256,7 @@ static int create_image(int platform_mode)
 
 int hibernation_snapshot(int platform_mode)
 {
-	int error, ftrace_save;
+	int error;
 
 	/* Free memory before shutting down devices. */
 	error = swsusp_shrink_memory();
@@ -269,7 +268,6 @@ int hibernation_snapshot(int platform_mode)
 		goto Close;
 
 	suspend_console();
-	ftrace_save = __ftrace_enabled_save();
 	error = device_suspend(PMSG_FREEZE);
 	if (error)
 		goto Recover_platform;
@@ -299,7 +297,6 @@ int hibernation_snapshot(int platform_mode)
  Resume_devices:
 	device_resume(in_suspend ?
 		(error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE);
-	__ftrace_enabled_restore(ftrace_save);
 	resume_console();
  Close:
 	platform_end(platform_mode);
@@ -370,11 +367,10 @@ static int resume_target_kernel(void)
 
 int hibernation_restore(int platform_mode)
 {
-	int error, ftrace_save;
+	int error;
 
 	pm_prepare_console();
 	suspend_console();
-	ftrace_save = __ftrace_enabled_save();
 	error = device_suspend(PMSG_QUIESCE);
 	if (error)
 		goto Finish;
@@ -389,7 +385,6 @@ int hibernation_restore(int platform_mode)
 	platform_restore_cleanup(platform_mode);
 	device_resume(PMSG_RECOVER);
  Finish:
-	__ftrace_enabled_restore(ftrace_save);
 	resume_console();
 	pm_restore_console();
 	return error;
@@ -402,7 +397,7 @@ int hibernation_restore(int platform_mode)
 
 int hibernation_platform_enter(void)
 {
-	int error, ftrace_save;
+	int error;
 
 	if (!hibernation_ops)
 		return -ENOSYS;
@@ -417,7 +412,6 @@ int hibernation_platform_enter(void)
 		goto Close;
 
 	suspend_console();
-	ftrace_save = __ftrace_enabled_save();
 	error = device_suspend(PMSG_HIBERNATE);
 	if (error) {
 		if (hibernation_ops->recover)
@@ -452,7 +446,6 @@ int hibernation_platform_enter(void)
 	hibernation_ops->finish();
  Resume_devices:
 	device_resume(PMSG_RESTORE);
-	__ftrace_enabled_restore(ftrace_save);
 	resume_console();
  Close:
 	hibernation_ops->end();

trunk/kernel/power/main.c

@@ -22,7 +22,6 @@
 #include <linux/freezer.h>
 #include <linux/vmstat.h>
 #include <linux/syscalls.h>
-#include <linux/ftrace.h>
 
 #include "power.h"
 
@@ -317,7 +316,7 @@ static int suspend_enter(suspend_state_t state)
  */
 int suspend_devices_and_enter(suspend_state_t state)
 {
-	int error, ftrace_save;
+	int error;
 
 	if (!suspend_ops)
 		return -ENOSYS;
@@ -328,7 +327,6 @@ int suspend_devices_and_enter(suspend_state_t state)
 			goto Close;
 	}
 	suspend_console();
-	ftrace_save = __ftrace_enabled_save();
 	suspend_test_start();
 	error = device_suspend(PMSG_SUSPEND);
 	if (error) {
@@ -360,7 +358,6 @@ int suspend_devices_and_enter(suspend_state_t state)
 	suspend_test_start();
 	device_resume(PMSG_RESUME);
 	suspend_test_finish("resume devices");
-	__ftrace_enabled_restore(ftrace_save);
 	resume_console();
  Close:
 	if (suspend_ops->end)

trunk/kernel/sched.c

@@ -5901,7 +5901,6 @@ 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);
 }
 
 /*