[mirror_ubuntu-jammy-kernel.git] / include / linux / ftrace.h

/*
 * Ftrace header.  For implementation details beyond the random comments
 * scattered below, see: Documentation/trace/ftrace-design.txt
 */

#ifndef _LINUX_FTRACE_H
#define _LINUX_FTRACE_H

#include <linux/trace_clock.h>
#include <linux/kallsyms.h>
#include <linux/linkage.h>
#include <linux/bitops.h>
#include <linux/module.h>
#include <linux/ktime.h>
#include <linux/sched.h>
#include <linux/types.h>
#include <linux/init.h>
#include <linux/fs.h>

#include <asm/ftrace.h>

#ifdef CONFIG_FUNCTION_TRACER

extern int ftrace_enabled;
extern int
ftrace_enable_sysctl(struct ctl_table *table, int write,
		     void __user *buffer, size_t *lenp,
		     loff_t *ppos);

typedef void (*ftrace_func_t)(unsigned long ip, unsigned long parent_ip);

struct ftrace_ops {
	ftrace_func_t	  func;
	struct ftrace_ops *next;
};

extern int function_trace_stop;

/*
 * Type of the current tracing.
 */
enum ftrace_tracing_type_t {
	FTRACE_TYPE_ENTER = 0, /* Hook the call of the function */
	FTRACE_TYPE_RETURN,	/* Hook the return of the function */
};

/* Current tracing type, default is FTRACE_TYPE_ENTER */
extern enum ftrace_tracing_type_t ftrace_tracing_type;

/**
 * ftrace_stop - stop function tracer.
 *
 * A quick way to stop the function tracer. Note this an on off switch,
 * it is not something that is recursive like preempt_disable.
 * This does not disable the calling of mcount, it only stops the
 * calling of functions from mcount.
 */
static inline void ftrace_stop(void)
{
	function_trace_stop = 1;
}

/**
 * ftrace_start - start the function tracer.
 *
 * This function is the inverse of ftrace_stop. This does not enable
 * the function tracing if the function tracer is disabled. This only
 * sets the function tracer flag to continue calling the functions
 * from mcount.
 */
static inline void ftrace_start(void)
{
	function_trace_stop = 0;
}

/*
 * The ftrace_ops must be a static and should also
 * be read_mostly.  These functions do modify read_mostly variables
 * so use them sparely. Never free an ftrace_op or modify the
 * next pointer after it has been registered. Even after unregistering
 * it, the next pointer may still be used internally.
 */
int register_ftrace_function(struct ftrace_ops *ops);
int unregister_ftrace_function(struct ftrace_ops *ops);
void clear_ftrace_function(void);

extern void ftrace_stub(unsigned long a0, unsigned long a1);

#else /* !CONFIG_FUNCTION_TRACER */
/*
 * (un)register_ftrace_function must be a macro since the ops parameter
 * must not be evaluated.
 */
#define register_ftrace_function(ops) ({ 0; })
#define unregister_ftrace_function(ops) ({ 0; })
static inline void clear_ftrace_function(void) { }
static inline void ftrace_kill(void) { }
static inline void ftrace_stop(void) { }
static inline void ftrace_start(void) { }
#endif /* CONFIG_FUNCTION_TRACER */

#ifdef CONFIG_STACK_TRACER
extern int stack_tracer_enabled;
int
stack_trace_sysctl(struct ctl_table *table, int write,
		   void __user *buffer, size_t *lenp,
		   loff_t *ppos);
#endif

struct ftrace_func_command {
	struct list_head	list;
	char			*name;
	int			(*func)(char *func, char *cmd,
					char *params, int enable);
};

#ifdef CONFIG_DYNAMIC_FTRACE

int ftrace_arch_code_modify_prepare(void);
int ftrace_arch_code_modify_post_process(void);

struct seq_file;

struct ftrace_probe_ops {
	void			(*func)(unsigned long ip,
					unsigned long parent_ip,
					void **data);
	int			(*callback)(unsigned long ip, void **data);
	void			(*free)(void **data);
	int			(*print)(struct seq_file *m,
					 unsigned long ip,
					 struct ftrace_probe_ops *ops,
					 void *data);
};

extern int
register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
			      void *data);
extern void
unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
				void *data);
extern void
unregister_ftrace_function_probe_func(char *glob, struct ftrace_probe_ops *ops);
extern void unregister_ftrace_function_probe_all(char *glob);

extern int ftrace_text_reserved(void *start, void *end);

enum {
	FTRACE_FL_FREE		= (1 << 0),
	FTRACE_FL_FAILED	= (1 << 1),
	FTRACE_FL_FILTER	= (1 << 2),
	FTRACE_FL_ENABLED	= (1 << 3),
	FTRACE_FL_NOTRACE	= (1 << 4),
	FTRACE_FL_CONVERTED	= (1 << 5),
};

struct dyn_ftrace {
	union {
		unsigned long		ip; /* address of mcount call-site */
		struct dyn_ftrace	*freelist;
	};
	union {
		unsigned long		flags;
		struct dyn_ftrace	*newlist;
	};
	struct dyn_arch_ftrace		arch;
};

int ftrace_force_update(void);
void ftrace_set_filter(unsigned char *buf, int len, int reset);

int register_ftrace_command(struct ftrace_func_command *cmd);
int unregister_ftrace_command(struct ftrace_func_command *cmd);

/* defined in arch */
extern int ftrace_ip_converted(unsigned long ip);
extern int ftrace_dyn_arch_init(void *data);
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);

#ifndef FTRACE_ADDR
#define FTRACE_ADDR ((unsigned long)ftrace_caller)
#endif
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
extern void ftrace_graph_caller(void);
extern int ftrace_enable_ftrace_graph_caller(void);
extern int ftrace_disable_ftrace_graph_caller(void);
#else
static inline int ftrace_enable_ftrace_graph_caller(void) { return 0; }
static inline int ftrace_disable_ftrace_graph_caller(void) { return 0; }
#endif

/**
 * ftrace_make_nop - convert code into nop
 * @mod: module structure if called by module load initialization
 * @rec: the mcount call site record
 * @addr: the address that the call site should be calling
 *
 * This is a very sensitive operation and great care needs
 * to be taken by the arch.  The operation should carefully
 * read the location, check to see if what is read is indeed
 * what we expect it to be, and then on success of the compare,
 * it should write to the location.
 *
 * The code segment at @rec->ip should be a caller to @addr
 *
 * Return must be:
 *  0 on success
 *  -EFAULT on error reading the location
 *  -EINVAL on a failed compare of the contents
 *  -EPERM  on error writing to the location
 * Any other value will be considered a failure.
 */
extern int ftrace_make_nop(struct module *mod,
			   struct dyn_ftrace *rec, unsigned long addr);

/**
 * ftrace_make_call - convert a nop call site into a call to addr
 * @rec: the mcount call site record
 * @addr: the address that the call site should call
 *
 * This is a very sensitive operation and great care needs
 * to be taken by the arch.  The operation should carefully
 * read the location, check to see if what is read is indeed
 * what we expect it to be, and then on success of the compare,
 * it should write to the location.
 *
 * The code segment at @rec->ip should be a nop
 *
 * Return must be:
 *  0 on success
 *  -EFAULT on error reading the location
 *  -EINVAL on a failed compare of the contents
 *  -EPERM  on error writing to the location
 * Any other value will be considered a failure.
 */
extern int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr);

/* May be defined in arch */
extern int ftrace_arch_read_dyn_info(char *buf, int size);

extern int skip_trace(unsigned long ip);

extern void ftrace_disable_daemon(void);
extern void ftrace_enable_daemon(void);
#else
static inline int skip_trace(unsigned long ip) { return 0; }
static inline int ftrace_force_update(void) { return 0; }
static inline void ftrace_set_filter(unsigned char *buf, int len, int reset)
{
}
static inline void ftrace_disable_daemon(void) { }
static inline void ftrace_enable_daemon(void) { }
static inline void ftrace_release_mod(struct module *mod) {}
static inline int register_ftrace_command(struct ftrace_func_command *cmd)
{
	return -EINVAL;
}
static inline int unregister_ftrace_command(char *cmd_name)
{
	return -EINVAL;
}
static inline int ftrace_text_reserved(void *start, void *end)
{
	return 0;
}
#endif /* CONFIG_DYNAMIC_FTRACE */

/* totally disable ftrace - can not re-enable after this */
void ftrace_kill(void);

static inline void tracer_disable(void)
{
#ifdef CONFIG_FUNCTION_TRACER
	ftrace_enabled = 0;
#endif
}

/*
 * Ftrace disable/restore without lock. Some synchronization mechanism
 * must be used to prevent ftrace_enabled to be changed between
 * disable/restore.
 */
static inline int __ftrace_enabled_save(void)
{
#ifdef CONFIG_FUNCTION_TRACER
	int saved_ftrace_enabled = ftrace_enabled;
	ftrace_enabled = 0;
	return saved_ftrace_enabled;
#else
	return 0;
#endif
}

static inline void __ftrace_enabled_restore(int enabled)
{
#ifdef CONFIG_FUNCTION_TRACER
	ftrace_enabled = enabled;
#endif
}

#ifndef HAVE_ARCH_CALLER_ADDR
# ifdef CONFIG_FRAME_POINTER
#  define CALLER_ADDR0 ((unsigned long)__builtin_return_address(0))
#  define CALLER_ADDR1 ((unsigned long)__builtin_return_address(1))
#  define CALLER_ADDR2 ((unsigned long)__builtin_return_address(2))
#  define CALLER_ADDR3 ((unsigned long)__builtin_return_address(3))
#  define CALLER_ADDR4 ((unsigned long)__builtin_return_address(4))
#  define CALLER_ADDR5 ((unsigned long)__builtin_return_address(5))
#  define CALLER_ADDR6 ((unsigned long)__builtin_return_address(6))
# else
#  define CALLER_ADDR0 ((unsigned long)__builtin_return_address(0))
#  define CALLER_ADDR1 0UL
#  define CALLER_ADDR2 0UL
#  define CALLER_ADDR3 0UL
#  define CALLER_ADDR4 0UL
#  define CALLER_ADDR5 0UL
#  define CALLER_ADDR6 0UL
# endif
#endif /* ifndef HAVE_ARCH_CALLER_ADDR */

#ifdef CONFIG_IRQSOFF_TRACER
  extern void time_hardirqs_on(unsigned long a0, unsigned long a1);
  extern void time_hardirqs_off(unsigned long a0, unsigned long a1);
#else
  static inline void time_hardirqs_on(unsigned long a0, unsigned long a1) { }
  static inline void time_hardirqs_off(unsigned long a0, unsigned long a1) { }
#endif

#ifdef CONFIG_PREEMPT_TRACER
  extern void trace_preempt_on(unsigned long a0, unsigned long a1);
  extern void trace_preempt_off(unsigned long a0, unsigned long a1);
#else
  static inline void trace_preempt_on(unsigned long a0, unsigned long a1) { }
  static inline void trace_preempt_off(unsigned long a0, unsigned long a1) { }
#endif

#ifdef CONFIG_FTRACE_MCOUNT_RECORD
extern void ftrace_init(void);
#else
static inline void ftrace_init(void) { }
#endif

/*
 * Structure that defines an entry function trace.
 */
struct ftrace_graph_ent {
	unsigned long func; /* Current function */
	int depth;
};

/*
 * Structure that defines a return function trace.
 */
struct ftrace_graph_ret {
	unsigned long func; /* Current function */
	unsigned long long calltime;
	unsigned long long rettime;
	/* Number of functions that overran the depth limit for current task */
	unsigned long overrun;
	int depth;
};

/* Type of the callback handlers for tracing function graph*/
typedef void (*trace_func_graph_ret_t)(struct ftrace_graph_ret *); /* return */
typedef int (*trace_func_graph_ent_t)(struct ftrace_graph_ent *); /* entry */

#ifdef CONFIG_FUNCTION_GRAPH_TRACER

/* for init task */
#define INIT_FTRACE_GRAPH		.ret_stack = NULL,

/*
 * Stack of return addresses for functions
 * of a thread.
 * Used in struct thread_info
 */
struct ftrace_ret_stack {
	unsigned long ret;
	unsigned long func;
	unsigned long long calltime;
	unsigned long long subtime;
	unsigned long fp;
};

/*
 * Primary handler of a function return.
 * It relays on ftrace_return_to_handler.
 * Defined in entry_32/64.S
 */
extern void return_to_handler(void);

extern int
ftrace_push_return_trace(unsigned long ret, unsigned long func, int *depth,
			 unsigned long frame_pointer);

/*
 * 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

/*
 * We want to which function is an entrypoint of a hardirq.
 * That will help us to put a signal on output.
 */
#define __irq_entry		 __attribute__((__section__(".irqentry.text")))

/* Limits of hardirq entrypoints */
extern char __irqentry_text_start[];
extern char __irqentry_text_end[];

#define FTRACE_RETFUNC_DEPTH 50
#define FTRACE_RETSTACK_ALLOC_SIZE 32
extern int register_ftrace_graph(trace_func_graph_ret_t retfunc,
				trace_func_graph_ent_t entryfunc);

extern void ftrace_graph_stop(void);

/* The current handlers in use */
extern trace_func_graph_ret_t ftrace_graph_return;
extern trace_func_graph_ent_t ftrace_graph_entry;

extern void unregister_ftrace_graph(void);

extern void ftrace_graph_init_task(struct task_struct *t);
extern void ftrace_graph_exit_task(struct task_struct *t);

static inline int task_curr_ret_stack(struct task_struct *t)
{
	return t->curr_ret_stack;
}

static inline void pause_graph_tracing(void)
{
	atomic_inc(&current->tracing_graph_pause);
}

static inline void unpause_graph_tracing(void)
{
	atomic_dec(&current->tracing_graph_pause);
}
#else /* !CONFIG_FUNCTION_GRAPH_TRACER */

#define __notrace_funcgraph
#define __irq_entry
#define INIT_FTRACE_GRAPH

static inline void ftrace_graph_init_task(struct task_struct *t) { }
static inline void ftrace_graph_exit_task(struct task_struct *t) { }

static inline int register_ftrace_graph(trace_func_graph_ret_t retfunc,
			  trace_func_graph_ent_t entryfunc)
{
	return -1;
}
static inline void unregister_ftrace_graph(void) { }

static inline int task_curr_ret_stack(struct task_struct *tsk)
{
	return -1;
}

static inline void pause_graph_tracing(void) { }
static inline void unpause_graph_tracing(void) { }
#endif /* CONFIG_FUNCTION_GRAPH_TRACER */

#ifdef CONFIG_TRACING

/* flags for current->trace */
enum {
	TSK_TRACE_FL_TRACE_BIT	= 0,
	TSK_TRACE_FL_GRAPH_BIT	= 1,
};
enum {
	TSK_TRACE_FL_TRACE	= 1 << TSK_TRACE_FL_TRACE_BIT,
	TSK_TRACE_FL_GRAPH	= 1 << TSK_TRACE_FL_GRAPH_BIT,
};

static inline void set_tsk_trace_trace(struct task_struct *tsk)
{
	set_bit(TSK_TRACE_FL_TRACE_BIT, &tsk->trace);
}

static inline void clear_tsk_trace_trace(struct task_struct *tsk)
{
	clear_bit(TSK_TRACE_FL_TRACE_BIT, &tsk->trace);
}

static inline int test_tsk_trace_trace(struct task_struct *tsk)
{
	return tsk->trace & TSK_TRACE_FL_TRACE;
}

static inline void set_tsk_trace_graph(struct task_struct *tsk)
{
	set_bit(TSK_TRACE_FL_GRAPH_BIT, &tsk->trace);
}

static inline void clear_tsk_trace_graph(struct task_struct *tsk)
{
	clear_bit(TSK_TRACE_FL_GRAPH_BIT, &tsk->trace);
}

static inline int test_tsk_trace_graph(struct task_struct *tsk)
{
	return tsk->trace & TSK_TRACE_FL_GRAPH;
}

enum ftrace_dump_mode;

extern enum ftrace_dump_mode ftrace_dump_on_oops;

#ifdef CONFIG_PREEMPT
#define INIT_TRACE_RECURSION		.trace_recursion = 0,
#endif

#endif /* CONFIG_TRACING */

#ifndef INIT_TRACE_RECURSION
#define INIT_TRACE_RECURSION
#endif

#ifdef CONFIG_FTRACE_SYSCALLS

unsigned long arch_syscall_addr(int nr);

#endif /* CONFIG_FTRACE_SYSCALLS */

#endif /* _LINUX_FTRACE_H */
Commit	Line	Data
	1	/*
	2	* Ftrace header. For implementation details beyond the random comments
	3	* scattered below, see: Documentation/trace/ftrace-design.txt
	4	*/
	5
	6	#ifndef _LINUX_FTRACE_H
	7	#define _LINUX_FTRACE_H
	8
	9	#include <linux/trace_clock.h>
	10	#include <linux/kallsyms.h>
	11	#include <linux/linkage.h>
	12	#include <linux/bitops.h>
	13	#include <linux/module.h>
	14	#include <linux/ktime.h>
	15	#include <linux/sched.h>
	16	#include <linux/types.h>
	17	#include <linux/init.h>
	18	#include <linux/fs.h>
	19
	20	#include <asm/ftrace.h>
	21
	22	#ifdef CONFIG_FUNCTION_TRACER
	23
	24	extern int ftrace_enabled;
	25	extern int
	26	ftrace_enable_sysctl(struct ctl_table *table, int write,
	27	void __user buffer, size_t lenp,
	28	loff_t *ppos);
	29
	30	typedef void (*ftrace_func_t)(unsigned long ip, unsigned long parent_ip);
	31
	32	struct ftrace_ops {
	33	ftrace_func_t func;
	34	struct ftrace_ops *next;
	35	};
	36
	37	extern int function_trace_stop;
	38
	39	/*
	40	* Type of the current tracing.
	41	*/
	42	enum ftrace_tracing_type_t {
	43	FTRACE_TYPE_ENTER = 0, /* Hook the call of the function */
	44	FTRACE_TYPE_RETURN, /* Hook the return of the function */
	45	};
	46
	47	/* Current tracing type, default is FTRACE_TYPE_ENTER */
	48	extern enum ftrace_tracing_type_t ftrace_tracing_type;
	49
	50	/**
	51	* ftrace_stop - stop function tracer.
	52	*
	53	* A quick way to stop the function tracer. Note this an on off switch,
	54	* it is not something that is recursive like preempt_disable.
	55	* This does not disable the calling of mcount, it only stops the
	56	* calling of functions from mcount.
	57	*/
	58	static inline void ftrace_stop(void)
	59	{
	60	function_trace_stop = 1;
	61	}
	62
	63	/**
	64	* ftrace_start - start the function tracer.
	65	*
	66	* This function is the inverse of ftrace_stop. This does not enable
	67	* the function tracing if the function tracer is disabled. This only
	68	* sets the function tracer flag to continue calling the functions
	69	* from mcount.
	70	*/
	71	static inline void ftrace_start(void)
	72	{
	73	function_trace_stop = 0;
	74	}
	75
	76	/*
	77	* The ftrace_ops must be a static and should also
	78	* be read_mostly. These functions do modify read_mostly variables
	79	* so use them sparely. Never free an ftrace_op or modify the
	80	* next pointer after it has been registered. Even after unregistering
	81	* it, the next pointer may still be used internally.
	82	*/
	83	int register_ftrace_function(struct ftrace_ops *ops);
	84	int unregister_ftrace_function(struct ftrace_ops *ops);
	85	void clear_ftrace_function(void);
	86
	87	extern void ftrace_stub(unsigned long a0, unsigned long a1);
	88
	89	#else /* !CONFIG_FUNCTION_TRACER */
	90	/*
	91	* (un)register_ftrace_function must be a macro since the ops parameter
	92	* must not be evaluated.
	93	*/
	94	#define register_ftrace_function(ops) ({ 0; })
	95	#define unregister_ftrace_function(ops) ({ 0; })
	96	static inline void clear_ftrace_function(void) { }
	97	static inline void ftrace_kill(void) { }
	98	static inline void ftrace_stop(void) { }
	99	static inline void ftrace_start(void) { }
	100	#endif /* CONFIG_FUNCTION_TRACER */
	101
	102	#ifdef CONFIG_STACK_TRACER
	103	extern int stack_tracer_enabled;
	104	int
	105	stack_trace_sysctl(struct ctl_table *table, int write,
	106	void __user buffer, size_t lenp,
	107	loff_t *ppos);
	108	#endif
	109
	110	struct ftrace_func_command {
	111	struct list_head list;
	112	char *name;
	113	int (func)(char func, char *cmd,
	114	char *params, int enable);
	115	};
	116
	117	#ifdef CONFIG_DYNAMIC_FTRACE
	118
	119	int ftrace_arch_code_modify_prepare(void);
	120	int ftrace_arch_code_modify_post_process(void);
	121
	122	struct seq_file;
	123
	124	struct ftrace_probe_ops {
	125	void (*func)(unsigned long ip,
	126	unsigned long parent_ip,
	127	void **data);
	128	int (callback)(unsigned long ip, void *data);
	129	void (free)(void *data);
	130	int (print)(struct seq_file m,
	131	unsigned long ip,
	132	struct ftrace_probe_ops *ops,
	133	void *data);
	134	};
	135
	136	extern int
	137	register_ftrace_function_probe(char glob, struct ftrace_probe_ops ops,
	138	void *data);
	139	extern void
	140	unregister_ftrace_function_probe(char glob, struct ftrace_probe_ops ops,
	141	void *data);
	142	extern void
	143	unregister_ftrace_function_probe_func(char glob, struct ftrace_probe_ops ops);
	144	extern void unregister_ftrace_function_probe_all(char *glob);
	145
	146	extern int ftrace_text_reserved(void start, void end);
	147
	148	enum {
	149	FTRACE_FL_FREE = (1 << 0),
	150	FTRACE_FL_FAILED = (1 << 1),
	151	FTRACE_FL_FILTER = (1 << 2),
	152	FTRACE_FL_ENABLED = (1 << 3),
	153	FTRACE_FL_NOTRACE = (1 << 4),
	154	FTRACE_FL_CONVERTED = (1 << 5),
	155	};
	156
	157	struct dyn_ftrace {
	158	union {
	159	unsigned long ip; /* address of mcount call-site */
	160	struct dyn_ftrace *freelist;
	161	};
	162	union {
	163	unsigned long flags;
	164	struct dyn_ftrace *newlist;
	165	};
	166	struct dyn_arch_ftrace arch;
	167	};
	168
	169	int ftrace_force_update(void);
	170	void ftrace_set_filter(unsigned char *buf, int len, int reset);
	171
	172	int register_ftrace_command(struct ftrace_func_command *cmd);
	173	int unregister_ftrace_command(struct ftrace_func_command *cmd);
	174
	175	/* defined in arch */
	176	extern int ftrace_ip_converted(unsigned long ip);
	177	extern int ftrace_dyn_arch_init(void *data);
	178	extern int ftrace_update_ftrace_func(ftrace_func_t func);
	179	extern void ftrace_caller(void);
	180	extern void ftrace_call(void);
	181	extern void mcount_call(void);
	182
	183	#ifndef FTRACE_ADDR
	184	#define FTRACE_ADDR ((unsigned long)ftrace_caller)
	185	#endif
	186	#ifdef CONFIG_FUNCTION_GRAPH_TRACER
	187	extern void ftrace_graph_caller(void);
	188	extern int ftrace_enable_ftrace_graph_caller(void);
	189	extern int ftrace_disable_ftrace_graph_caller(void);
	190	#else
	191	static inline int ftrace_enable_ftrace_graph_caller(void) { return 0; }
	192	static inline int ftrace_disable_ftrace_graph_caller(void) { return 0; }
	193	#endif
	194
	195	/**
	196	* ftrace_make_nop - convert code into nop
	197	* @mod: module structure if called by module load initialization
	198	* @rec: the mcount call site record
	199	* @addr: the address that the call site should be calling
	200	*
	201	* This is a very sensitive operation and great care needs
	202	* to be taken by the arch. The operation should carefully
	203	* read the location, check to see if what is read is indeed
	204	* what we expect it to be, and then on success of the compare,
	205	* it should write to the location.
	206	*
	207	* The code segment at @rec->ip should be a caller to @addr
	208	*
	209	* Return must be:
	210	* 0 on success
	211	* -EFAULT on error reading the location
	212	* -EINVAL on a failed compare of the contents
	213	* -EPERM on error writing to the location
	214	* Any other value will be considered a failure.
	215	*/
	216	extern int ftrace_make_nop(struct module *mod,
	217	struct dyn_ftrace *rec, unsigned long addr);
	218
	219	/**
	220	* ftrace_make_call - convert a nop call site into a call to addr
	221	* @rec: the mcount call site record
	222	* @addr: the address that the call site should call
	223	*
	224	* This is a very sensitive operation and great care needs
	225	* to be taken by the arch. The operation should carefully
	226	* read the location, check to see if what is read is indeed
	227	* what we expect it to be, and then on success of the compare,
	228	* it should write to the location.
	229	*
	230	* The code segment at @rec->ip should be a nop
	231	*
	232	* Return must be:
	233	* 0 on success
	234	* -EFAULT on error reading the location
	235	* -EINVAL on a failed compare of the contents
	236	* -EPERM on error writing to the location
	237	* Any other value will be considered a failure.
	238	*/
	239	extern int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr);
	240
	241	/* May be defined in arch */
	242	extern int ftrace_arch_read_dyn_info(char *buf, int size);
	243
	244	extern int skip_trace(unsigned long ip);
	245
	246	extern void ftrace_disable_daemon(void);
	247	extern void ftrace_enable_daemon(void);
	248	#else
	249	static inline int skip_trace(unsigned long ip) { return 0; }
	250	static inline int ftrace_force_update(void) { return 0; }
	251	static inline void ftrace_set_filter(unsigned char *buf, int len, int reset)
	252	{
	253	}
	254	static inline void ftrace_disable_daemon(void) { }
	255	static inline void ftrace_enable_daemon(void) { }
	256	static inline void ftrace_release_mod(struct module *mod) {}
	257	static inline int register_ftrace_command(struct ftrace_func_command *cmd)
	258	{
	259	return -EINVAL;
	260	}
	261	static inline int unregister_ftrace_command(char *cmd_name)
	262	{
	263	return -EINVAL;
	264	}
	265	static inline int ftrace_text_reserved(void start, void end)
	266	{
	267	return 0;
	268	}
	269	#endif /* CONFIG_DYNAMIC_FTRACE */
	270
	271	/* totally disable ftrace - can not re-enable after this */
	272	void ftrace_kill(void);
	273
	274	static inline void tracer_disable(void)
	275	{
	276	#ifdef CONFIG_FUNCTION_TRACER
	277	ftrace_enabled = 0;
	278	#endif
	279	}
	280
	281	/*
	282	* Ftrace disable/restore without lock. Some synchronization mechanism
	283	* must be used to prevent ftrace_enabled to be changed between
	284	* disable/restore.
	285	*/
	286	static inline int __ftrace_enabled_save(void)
	287	{
	288	#ifdef CONFIG_FUNCTION_TRACER
	289	int saved_ftrace_enabled = ftrace_enabled;
	290	ftrace_enabled = 0;
	291	return saved_ftrace_enabled;
	292	#else
	293	return 0;
	294	#endif
	295	}
	296
	297	static inline void __ftrace_enabled_restore(int enabled)
	298	{
	299	#ifdef CONFIG_FUNCTION_TRACER
	300	ftrace_enabled = enabled;
	301	#endif
	302	}
	303
	304	#ifndef HAVE_ARCH_CALLER_ADDR
	305	# ifdef CONFIG_FRAME_POINTER
	306	# define CALLER_ADDR0 ((unsigned long)__builtin_return_address(0))
	307	# define CALLER_ADDR1 ((unsigned long)__builtin_return_address(1))
	308	# define CALLER_ADDR2 ((unsigned long)__builtin_return_address(2))
	309	# define CALLER_ADDR3 ((unsigned long)__builtin_return_address(3))
	310	# define CALLER_ADDR4 ((unsigned long)__builtin_return_address(4))
	311	# define CALLER_ADDR5 ((unsigned long)__builtin_return_address(5))
	312	# define CALLER_ADDR6 ((unsigned long)__builtin_return_address(6))
	313	# else
	314	# define CALLER_ADDR0 ((unsigned long)__builtin_return_address(0))
	315	# define CALLER_ADDR1 0UL
	316	# define CALLER_ADDR2 0UL
	317	# define CALLER_ADDR3 0UL
	318	# define CALLER_ADDR4 0UL
	319	# define CALLER_ADDR5 0UL
	320	# define CALLER_ADDR6 0UL
	321	# endif
	322	#endif /* ifndef HAVE_ARCH_CALLER_ADDR */
	323
	324	#ifdef CONFIG_IRQSOFF_TRACER
	325	extern void time_hardirqs_on(unsigned long a0, unsigned long a1);
	326	extern void time_hardirqs_off(unsigned long a0, unsigned long a1);
	327	#else
	328	static inline void time_hardirqs_on(unsigned long a0, unsigned long a1) { }
	329	static inline void time_hardirqs_off(unsigned long a0, unsigned long a1) { }
	330	#endif
	331
	332	#ifdef CONFIG_PREEMPT_TRACER
	333	extern void trace_preempt_on(unsigned long a0, unsigned long a1);
	334	extern void trace_preempt_off(unsigned long a0, unsigned long a1);
	335	#else
	336	static inline void trace_preempt_on(unsigned long a0, unsigned long a1) { }
	337	static inline void trace_preempt_off(unsigned long a0, unsigned long a1) { }
	338	#endif
	339
	340	#ifdef CONFIG_FTRACE_MCOUNT_RECORD
	341	extern void ftrace_init(void);
	342	#else
	343	static inline void ftrace_init(void) { }
	344	#endif
	345
	346	/*
	347	* Structure that defines an entry function trace.
	348	*/
	349	struct ftrace_graph_ent {
	350	unsigned long func; /* Current function */
	351	int depth;
	352	};
	353
	354	/*
	355	* Structure that defines a return function trace.
	356	*/
	357	struct ftrace_graph_ret {
	358	unsigned long func; /* Current function */
	359	unsigned long long calltime;
	360	unsigned long long rettime;
	361	/* Number of functions that overran the depth limit for current task */
	362	unsigned long overrun;
	363	int depth;
	364	};
	365
	366	/* Type of the callback handlers for tracing function graph*/
	367	typedef void (trace_func_graph_ret_t)(struct ftrace_graph_ret ); /* return */
	368	typedef int (trace_func_graph_ent_t)(struct ftrace_graph_ent ); /* entry */
	369
	370	#ifdef CONFIG_FUNCTION_GRAPH_TRACER
	371
	372	/* for init task */
	373	#define INIT_FTRACE_GRAPH .ret_stack = NULL,
	374
	375	/*
	376	* Stack of return addresses for functions
	377	* of a thread.
	378	* Used in struct thread_info
	379	*/
	380	struct ftrace_ret_stack {
	381	unsigned long ret;
	382	unsigned long func;
	383	unsigned long long calltime;
	384	unsigned long long subtime;
	385	unsigned long fp;
	386	};
	387
	388	/*
	389	* Primary handler of a function return.
	390	* It relays on ftrace_return_to_handler.
	391	* Defined in entry_32/64.S
	392	*/
	393	extern void return_to_handler(void);
	394
	395	extern int
	396	ftrace_push_return_trace(unsigned long ret, unsigned long func, int *depth,
	397	unsigned long frame_pointer);
	398
	399	/*
	400	* Sometimes we don't want to trace a function with the function
	401	* graph tracer but we want them to keep traced by the usual function
	402	* tracer if the function graph tracer is not configured.
	403	*/
	404	#define __notrace_funcgraph notrace
	405
	406	/*
	407	* We want to which function is an entrypoint of a hardirq.
	408	* That will help us to put a signal on output.
	409	*/
	410	#define __irq_entry __attribute__((__section__(".irqentry.text")))
	411
	412	/* Limits of hardirq entrypoints */
	413	extern char __irqentry_text_start[];
	414	extern char __irqentry_text_end[];
	415
	416	#define FTRACE_RETFUNC_DEPTH 50
	417	#define FTRACE_RETSTACK_ALLOC_SIZE 32
	418	extern int register_ftrace_graph(trace_func_graph_ret_t retfunc,
	419	trace_func_graph_ent_t entryfunc);
	420
	421	extern void ftrace_graph_stop(void);
	422
	423	/* The current handlers in use */
	424	extern trace_func_graph_ret_t ftrace_graph_return;
	425	extern trace_func_graph_ent_t ftrace_graph_entry;
	426
	427	extern void unregister_ftrace_graph(void);
	428
	429	extern void ftrace_graph_init_task(struct task_struct *t);
	430	extern void ftrace_graph_exit_task(struct task_struct *t);
	431
	432	static inline int task_curr_ret_stack(struct task_struct *t)
	433	{
	434	return t->curr_ret_stack;
	435	}
	436
	437	static inline void pause_graph_tracing(void)
	438	{
	439	atomic_inc(&current->tracing_graph_pause);
	440	}
	441
	442	static inline void unpause_graph_tracing(void)
	443	{
	444	atomic_dec(&current->tracing_graph_pause);
	445	}
	446	#else /* !CONFIG_FUNCTION_GRAPH_TRACER */
	447
	448	#define __notrace_funcgraph
	449	#define __irq_entry
	450	#define INIT_FTRACE_GRAPH
	451
	452	static inline void ftrace_graph_init_task(struct task_struct *t) { }
	453	static inline void ftrace_graph_exit_task(struct task_struct *t) { }
	454
	455	static inline int register_ftrace_graph(trace_func_graph_ret_t retfunc,
	456	trace_func_graph_ent_t entryfunc)
	457	{
	458	return -1;
	459	}
	460	static inline void unregister_ftrace_graph(void) { }
	461
	462	static inline int task_curr_ret_stack(struct task_struct *tsk)
	463	{
	464	return -1;
	465	}
	466
	467	static inline void pause_graph_tracing(void) { }
	468	static inline void unpause_graph_tracing(void) { }
	469	#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
	470
	471	#ifdef CONFIG_TRACING
	472
	473	/* flags for current->trace */
	474	enum {
	475	TSK_TRACE_FL_TRACE_BIT = 0,
	476	TSK_TRACE_FL_GRAPH_BIT = 1,
	477	};
	478	enum {
	479	TSK_TRACE_FL_TRACE = 1 << TSK_TRACE_FL_TRACE_BIT,
	480	TSK_TRACE_FL_GRAPH = 1 << TSK_TRACE_FL_GRAPH_BIT,
	481	};
	482
	483	static inline void set_tsk_trace_trace(struct task_struct *tsk)
	484	{
	485	set_bit(TSK_TRACE_FL_TRACE_BIT, &tsk->trace);
	486	}
	487
	488	static inline void clear_tsk_trace_trace(struct task_struct *tsk)
	489	{
	490	clear_bit(TSK_TRACE_FL_TRACE_BIT, &tsk->trace);
	491	}
	492
	493	static inline int test_tsk_trace_trace(struct task_struct *tsk)
	494	{
	495	return tsk->trace & TSK_TRACE_FL_TRACE;
	496	}
	497
	498	static inline void set_tsk_trace_graph(struct task_struct *tsk)
	499	{
	500	set_bit(TSK_TRACE_FL_GRAPH_BIT, &tsk->trace);
	501	}
	502
	503	static inline void clear_tsk_trace_graph(struct task_struct *tsk)
	504	{
	505	clear_bit(TSK_TRACE_FL_GRAPH_BIT, &tsk->trace);
	506	}
	507
	508	static inline int test_tsk_trace_graph(struct task_struct *tsk)
	509	{
	510	return tsk->trace & TSK_TRACE_FL_GRAPH;
	511	}
	512
	513	enum ftrace_dump_mode;
	514
	515	extern enum ftrace_dump_mode ftrace_dump_on_oops;
	516
	517	#ifdef CONFIG_PREEMPT
	518	#define INIT_TRACE_RECURSION .trace_recursion = 0,
	519	#endif
	520
	521	#endif /* CONFIG_TRACING */
	522
	523	#ifndef INIT_TRACE_RECURSION
	524	#define INIT_TRACE_RECURSION
	525	#endif
	526
	527	#ifdef CONFIG_FTRACE_SYSCALLS
	528
	529	unsigned long arch_syscall_addr(int nr);
	530
	531	#endif /* CONFIG_FTRACE_SYSCALLS */
	532
	533	#endif /* _LINUX_FTRACE_H */