[mirror_ubuntu-zesty-kernel.git] / kernel / trace / trace.h

#ifndef _LINUX_KERNEL_TRACE_H
#define _LINUX_KERNEL_TRACE_H

#include <linux/fs.h>
#include <asm/atomic.h>
#include <linux/sched.h>
#include <linux/clocksource.h>
#include <linux/ring_buffer.h>
#include <linux/mmiotrace.h>
#include <linux/ftrace.h>
#include <trace/boot.h>

enum trace_type {
	__TRACE_FIRST_TYPE = 0,

	TRACE_FN,
	TRACE_CTX,
	TRACE_WAKE,
	TRACE_CONT,
	TRACE_STACK,
	TRACE_PRINT,
	TRACE_SPECIAL,
	TRACE_MMIO_RW,
	TRACE_MMIO_MAP,
	TRACE_BRANCH,
	TRACE_BOOT_CALL,
	TRACE_BOOT_RET,
	TRACE_FN_RET,

	__TRACE_LAST_TYPE
};

/*
 * The trace entry - the most basic unit of tracing. This is what
 * is printed in the end as a single line in the trace output, such as:
 *
 *     bash-15816 [01]   235.197585: idle_cpu <- irq_enter
 */
struct trace_entry {
	unsigned char		type;
	unsigned char		cpu;
	unsigned char		flags;
	unsigned char		preempt_count;
	int			pid;
};

/*
 * Function trace entry - function address and parent function addres:
 */
struct ftrace_entry {
	struct trace_entry	ent;
	unsigned long		ip;
	unsigned long		parent_ip;
};

/* Function return entry */
struct ftrace_ret_entry {
	struct trace_entry	ent;
	unsigned long		ip;
	unsigned long		parent_ip;
	unsigned long long	calltime;
	unsigned long long	rettime;
	unsigned long		overrun;
};
extern struct tracer boot_tracer;

/*
 * Context switch trace entry - which task (and prio) we switched from/to:
 */
struct ctx_switch_entry {
	struct trace_entry	ent;
	unsigned int		prev_pid;
	unsigned char		prev_prio;
	unsigned char		prev_state;
	unsigned int		next_pid;
	unsigned char		next_prio;
	unsigned char		next_state;
	unsigned int		next_cpu;
};

/*
 * Special (free-form) trace entry:
 */
struct special_entry {
	struct trace_entry	ent;
	unsigned long		arg1;
	unsigned long		arg2;
	unsigned long		arg3;
};

/*
 * Stack-trace entry:
 */

#define FTRACE_STACK_ENTRIES	8

struct stack_entry {
	struct trace_entry	ent;
	unsigned long		caller[FTRACE_STACK_ENTRIES];
};

/*
 * ftrace_printk entry:
 */
struct print_entry {
	struct trace_entry	ent;
	unsigned long		ip;
	char			buf[];
};

#define TRACE_OLD_SIZE		88

struct trace_field_cont {
	unsigned char		type;
	/* Temporary till we get rid of this completely */
	char			buf[TRACE_OLD_SIZE - 1];
};

struct trace_mmiotrace_rw {
	struct trace_entry	ent;
	struct mmiotrace_rw	rw;
};

struct trace_mmiotrace_map {
	struct trace_entry	ent;
	struct mmiotrace_map	map;
};

struct trace_boot_call {
	struct trace_entry	ent;
	struct boot_trace_call boot_call;
};

struct trace_boot_ret {
	struct trace_entry	ent;
	struct boot_trace_ret boot_ret;
};

#define TRACE_FUNC_SIZE 30
#define TRACE_FILE_SIZE 20
struct trace_branch {
	struct trace_entry	ent;
	unsigned	        line;
	char			func[TRACE_FUNC_SIZE+1];
	char			file[TRACE_FILE_SIZE+1];
	char			correct;
};

/*
 * trace_flag_type is an enumeration that holds different
 * states when a trace occurs. These are:
 *  IRQS_OFF		- interrupts were disabled
 *  IRQS_NOSUPPORT 	- arch does not support irqs_disabled_flags
 *  NEED_RESCED		- reschedule is requested
 *  HARDIRQ		- inside an interrupt handler
 *  SOFTIRQ		- inside a softirq handler
 *  CONT		- multiple entries hold the trace item
 */
enum trace_flag_type {
	TRACE_FLAG_IRQS_OFF		= 0x01,
	TRACE_FLAG_IRQS_NOSUPPORT	= 0x02,
	TRACE_FLAG_NEED_RESCHED		= 0x04,
	TRACE_FLAG_HARDIRQ		= 0x08,
	TRACE_FLAG_SOFTIRQ		= 0x10,
	TRACE_FLAG_CONT			= 0x20,
};

#define TRACE_BUF_SIZE		1024

/*
 * The CPU trace array - it consists of thousands of trace entries
 * plus some other descriptor data: (for example which task started
 * the trace, etc.)
 */
struct trace_array_cpu {
	atomic_t		disabled;

	/* these fields get copied into max-trace: */
	unsigned long		trace_idx;
	unsigned long		overrun;
	unsigned long		saved_latency;
	unsigned long		critical_start;
	unsigned long		critical_end;
	unsigned long		critical_sequence;
	unsigned long		nice;
	unsigned long		policy;
	unsigned long		rt_priority;
	cycle_t			preempt_timestamp;
	pid_t			pid;
	uid_t			uid;
	char			comm[TASK_COMM_LEN];
};

struct trace_iterator;

/*
 * The trace array - an array of per-CPU trace arrays. This is the
 * highest level data structure that individual tracers deal with.
 * They have on/off state as well:
 */
struct trace_array {
	struct ring_buffer	*buffer;
	unsigned long		entries;
	int			cpu;
	cycle_t			time_start;
	struct task_struct	*waiter;
	struct trace_array_cpu	*data[NR_CPUS];
};

#define FTRACE_CMP_TYPE(var, type) \
	__builtin_types_compatible_p(typeof(var), type *)

#undef IF_ASSIGN
#define IF_ASSIGN(var, entry, etype, id)		\
	if (FTRACE_CMP_TYPE(var, etype)) {		\
		var = (typeof(var))(entry);		\
		WARN_ON(id && (entry)->type != id);	\
		break;					\
	}

/* Will cause compile errors if type is not found. */
extern void __ftrace_bad_type(void);

/*
 * The trace_assign_type is a verifier that the entry type is
 * the same as the type being assigned. To add new types simply
 * add a line with the following format:
 *
 * IF_ASSIGN(var, ent, type, id);
 *
 *  Where "type" is the trace type that includes the trace_entry
 *  as the "ent" item. And "id" is the trace identifier that is
 *  used in the trace_type enum.
 *
 *  If the type can have more than one id, then use zero.
 */
#define trace_assign_type(var, ent)					\
	do {								\
		IF_ASSIGN(var, ent, struct ftrace_entry, TRACE_FN);	\
		IF_ASSIGN(var, ent, struct ctx_switch_entry, 0);	\
		IF_ASSIGN(var, ent, struct trace_field_cont, TRACE_CONT); \
		IF_ASSIGN(var, ent, struct stack_entry, TRACE_STACK);	\
		IF_ASSIGN(var, ent, struct print_entry, TRACE_PRINT);	\
		IF_ASSIGN(var, ent, struct special_entry, 0);		\
		IF_ASSIGN(var, ent, struct trace_mmiotrace_rw,		\
			  TRACE_MMIO_RW);				\
		IF_ASSIGN(var, ent, struct trace_mmiotrace_map,		\
			  TRACE_MMIO_MAP);				\
		IF_ASSIGN(var, ent, struct trace_boot_call, TRACE_BOOT_CALL);\
		IF_ASSIGN(var, ent, struct trace_boot_ret, TRACE_BOOT_RET);\
		IF_ASSIGN(var, ent, struct trace_branch, TRACE_BRANCH); \
		IF_ASSIGN(var, ent, struct ftrace_ret_entry, TRACE_FN_RET);\
		__ftrace_bad_type();					\
	} while (0)

/* Return values for print_line callback */
enum print_line_t {
	TRACE_TYPE_PARTIAL_LINE	= 0,	/* Retry after flushing the seq */
	TRACE_TYPE_HANDLED	= 1,
	TRACE_TYPE_UNHANDLED	= 2	/* Relay to other output functions */
};


/*
 * An option specific to a tracer. This is a boolean value.
 * The bit is the bit index that sets its value on the
 * flags value in struct tracer_flags.
 */
struct tracer_opt {
	const char 	*name; /* Will appear on the trace_options file */
	u32 		bit; /* Mask assigned in val field in tracer_flags */
};

/*
 * The set of specific options for a tracer. Your tracer
 * have to set the initial value of the flags val.
 */
struct tracer_flags {
	u32			val;
	struct tracer_opt 	*opts;
};

/* Makes more easy to define a tracer opt */
#define TRACER_OPT(s, b)	.name = #s, .bit = b

/*
 * A specific tracer, represented by methods that operate on a trace array:
 */
struct tracer {
	const char		*name;
	/* Your tracer should raise a warning if init fails */
	int			(*init)(struct trace_array *tr);
	void			(*reset)(struct trace_array *tr);
	void			(*start)(struct trace_array *tr);
	void			(*stop)(struct trace_array *tr);
	void			(*open)(struct trace_iterator *iter);
	void			(*pipe_open)(struct trace_iterator *iter);
	void			(*close)(struct trace_iterator *iter);
	ssize_t			(*read)(struct trace_iterator *iter,
					struct file *filp, char __user *ubuf,
					size_t cnt, loff_t *ppos);
#ifdef CONFIG_FTRACE_STARTUP_TEST
	int			(*selftest)(struct tracer *trace,
					    struct trace_array *tr);
#endif
	enum print_line_t	(*print_line)(struct trace_iterator *iter);
	/* If you handled the flag setting, return 0 */
	int			(*set_flag)(u32 old_flags, u32 bit, int set);
	struct tracer		*next;
	int			print_max;
	struct tracer_flags 	*flags;
};

struct trace_seq {
	unsigned char		buffer[PAGE_SIZE];
	unsigned int		len;
	unsigned int		readpos;
};

/*
 * Trace iterator - used by printout routines who present trace
 * results to users and which routines might sleep, etc:
 */
struct trace_iterator {
	struct trace_array	*tr;
	struct tracer		*trace;
	void			*private;
	struct ring_buffer_iter	*buffer_iter[NR_CPUS];

	/* The below is zeroed out in pipe_read */
	struct trace_seq	seq;
	struct trace_entry	*ent;
	int			cpu;
	u64			ts;

	unsigned long		iter_flags;
	loff_t			pos;
	long			idx;

	cpumask_t		started;
};

int tracing_is_enabled(void);
void trace_wake_up(void);
void tracing_reset(struct trace_array *tr, int cpu);
int tracing_open_generic(struct inode *inode, struct file *filp);
struct dentry *tracing_init_dentry(void);
void init_tracer_sysprof_debugfs(struct dentry *d_tracer);

struct trace_entry *tracing_get_trace_entry(struct trace_array *tr,
						struct trace_array_cpu *data);
void tracing_generic_entry_update(struct trace_entry *entry,
				  unsigned long flags,
				  int pc);

void ftrace(struct trace_array *tr,
			    struct trace_array_cpu *data,
			    unsigned long ip,
			    unsigned long parent_ip,
			    unsigned long flags, int pc);
void tracing_sched_switch_trace(struct trace_array *tr,
				struct trace_array_cpu *data,
				struct task_struct *prev,
				struct task_struct *next,
				unsigned long flags, int pc);
void tracing_record_cmdline(struct task_struct *tsk);

void tracing_sched_wakeup_trace(struct trace_array *tr,
				struct trace_array_cpu *data,
				struct task_struct *wakee,
				struct task_struct *cur,
				unsigned long flags, int pc);
void trace_special(struct trace_array *tr,
		   struct trace_array_cpu *data,
		   unsigned long arg1,
		   unsigned long arg2,
		   unsigned long arg3, int pc);
void trace_function(struct trace_array *tr,
		    struct trace_array_cpu *data,
		    unsigned long ip,
		    unsigned long parent_ip,
		    unsigned long flags, int pc);
void
trace_function_return(struct ftrace_retfunc *trace);

void tracing_start_cmdline_record(void);
void tracing_stop_cmdline_record(void);
void tracing_sched_switch_assign_trace(struct trace_array *tr);
void tracing_stop_sched_switch_record(void);
void tracing_start_sched_switch_record(void);
int register_tracer(struct tracer *type);
void unregister_tracer(struct tracer *type);

extern unsigned long nsecs_to_usecs(unsigned long nsecs);

extern unsigned long tracing_max_latency;
extern unsigned long tracing_thresh;

void update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu);
void update_max_tr_single(struct trace_array *tr,
			  struct task_struct *tsk, int cpu);

extern cycle_t ftrace_now(int cpu);

#ifdef CONFIG_FUNCTION_TRACER
void tracing_start_function_trace(void);
void tracing_stop_function_trace(void);
#else
# define tracing_start_function_trace()		do { } while (0)
# define tracing_stop_function_trace()		do { } while (0)
#endif

#ifdef CONFIG_CONTEXT_SWITCH_TRACER
typedef void
(*tracer_switch_func_t)(void *private,
			void *__rq,
			struct task_struct *prev,
			struct task_struct *next);

struct tracer_switch_ops {
	tracer_switch_func_t		func;
	void				*private;
	struct tracer_switch_ops	*next;
};

#endif /* CONFIG_CONTEXT_SWITCH_TRACER */

#ifdef CONFIG_DYNAMIC_FTRACE
extern unsigned long ftrace_update_tot_cnt;
#define DYN_FTRACE_TEST_NAME trace_selftest_dynamic_test_func
extern int DYN_FTRACE_TEST_NAME(void);
#endif

#ifdef CONFIG_FTRACE_STARTUP_TEST
extern int trace_selftest_startup_function(struct tracer *trace,
					   struct trace_array *tr);
extern int trace_selftest_startup_irqsoff(struct tracer *trace,
					  struct trace_array *tr);
extern int trace_selftest_startup_preemptoff(struct tracer *trace,
					     struct trace_array *tr);
extern int trace_selftest_startup_preemptirqsoff(struct tracer *trace,
						 struct trace_array *tr);
extern int trace_selftest_startup_wakeup(struct tracer *trace,
					 struct trace_array *tr);
extern int trace_selftest_startup_nop(struct tracer *trace,
					 struct trace_array *tr);
extern int trace_selftest_startup_sched_switch(struct tracer *trace,
					       struct trace_array *tr);
extern int trace_selftest_startup_sysprof(struct tracer *trace,
					       struct trace_array *tr);
extern int trace_selftest_startup_branch(struct tracer *trace,
					 struct trace_array *tr);
#endif /* CONFIG_FTRACE_STARTUP_TEST */

extern void *head_page(struct trace_array_cpu *data);
extern int trace_seq_printf(struct trace_seq *s, const char *fmt, ...);
extern void trace_seq_print_cont(struct trace_seq *s,
				 struct trace_iterator *iter);

extern int
seq_print_ip_sym(struct trace_seq *s, unsigned long ip,
		unsigned long sym_flags);
extern ssize_t trace_seq_to_user(struct trace_seq *s, char __user *ubuf,
				 size_t cnt);
extern long ns2usecs(cycle_t nsec);
extern int trace_vprintk(unsigned long ip, const char *fmt, va_list args);

extern unsigned long trace_flags;

/* Standard output formatting function used for function return traces */
#ifdef CONFIG_FUNCTION_RET_TRACER
extern enum print_line_t print_return_function(struct trace_iterator *iter);
#else
static inline enum print_line_t
print_return_function(struct trace_iterator *iter)
{
	return TRACE_TYPE_UNHANDLED;
}
#endif

/*
 * trace_iterator_flags is an enumeration that defines bit
 * positions into trace_flags that controls the output.
 *
 * NOTE: These bits must match the trace_options array in
 *       trace.c.
 */
enum trace_iterator_flags {
	TRACE_ITER_PRINT_PARENT		= 0x01,
	TRACE_ITER_SYM_OFFSET		= 0x02,
	TRACE_ITER_SYM_ADDR		= 0x04,
	TRACE_ITER_VERBOSE		= 0x08,
	TRACE_ITER_RAW			= 0x10,
	TRACE_ITER_HEX			= 0x20,
	TRACE_ITER_BIN			= 0x40,
	TRACE_ITER_BLOCK		= 0x80,
	TRACE_ITER_STACKTRACE		= 0x100,
	TRACE_ITER_SCHED_TREE		= 0x200,
	TRACE_ITER_PRINTK		= 0x400,
	TRACE_ITER_PREEMPTONLY		= 0x800,
	TRACE_ITER_BRANCH		= 0x1000,
	TRACE_ITER_ANNOTATE		= 0x2000,
};

/*
 * TRACE_ITER_SYM_MASK masks the options in trace_flags that
 * control the output of kernel symbols.
 */
#define TRACE_ITER_SYM_MASK \
	(TRACE_ITER_PRINT_PARENT|TRACE_ITER_SYM_OFFSET|TRACE_ITER_SYM_ADDR)

extern struct tracer nop_trace;

/**
 * ftrace_preempt_disable - disable preemption scheduler safe
 *
 * When tracing can happen inside the scheduler, there exists
 * cases that the tracing might happen before the need_resched
 * flag is checked. If this happens and the tracer calls
 * preempt_enable (after a disable), a schedule might take place
 * causing an infinite recursion.
 *
 * To prevent this, we read the need_recshed flag before
 * disabling preemption. When we want to enable preemption we
 * check the flag, if it is set, then we call preempt_enable_no_resched.
 * Otherwise, we call preempt_enable.
 *
 * The rational for doing the above is that if need resched is set
 * and we have yet to reschedule, we are either in an atomic location
 * (where we do not need to check for scheduling) or we are inside
 * the scheduler and do not want to resched.
 */
static inline int ftrace_preempt_disable(void)
{
	int resched;

	resched = need_resched();
	preempt_disable_notrace();

	return resched;
}

/**
 * ftrace_preempt_enable - enable preemption scheduler safe
 * @resched: the return value from ftrace_preempt_disable
 *
 * This is a scheduler safe way to enable preemption and not miss
 * any preemption checks. The disabled saved the state of preemption.
 * If resched is set, then we were either inside an atomic or
 * are inside the scheduler (we would have already scheduled
 * otherwise). In this case, we do not want to call normal
 * preempt_enable, but preempt_enable_no_resched instead.
 */
static inline void ftrace_preempt_enable(int resched)
{
	if (resched)
		preempt_enable_no_resched_notrace();
	else
		preempt_enable_notrace();
}

#ifdef CONFIG_BRANCH_TRACER
extern int enable_branch_tracing(struct trace_array *tr);
extern void disable_branch_tracing(void);
static inline int trace_branch_enable(struct trace_array *tr)
{
	if (trace_flags & TRACE_ITER_BRANCH)
		return enable_branch_tracing(tr);
	return 0;
}
static inline void trace_branch_disable(void)
{
	/* due to races, always disable */
	disable_branch_tracing();
}
#else
static inline int trace_branch_enable(struct trace_array *tr)
{
	return 0;
}
static inline void trace_branch_disable(void)
{
}
#endif /* CONFIG_BRANCH_TRACER */

#endif /* _LINUX_KERNEL_TRACE_H */
Commit	Line	Data
bc0c38d1 SR	1	#ifndef _LINUX_KERNEL_TRACE_H
	2	#define _LINUX_KERNEL_TRACE_H
	3
	4	#include <linux/fs.h>
	5	#include <asm/atomic.h>
	6	#include <linux/sched.h>
	7	#include <linux/clocksource.h>
3928a8a2	8	#include <linux/ring_buffer.h>
bd8ac686	9	#include <linux/mmiotrace.h>
d13744cd	10	#include <linux/ftrace.h>
3f5ec136	11	#include <trace/boot.h>
bc0c38d1	12
72829bc3 TG	13	enum trace_type {
	14	__TRACE_FIRST_TYPE = 0,
	15
	16	TRACE_FN,
	17	TRACE_CTX,
	18	TRACE_WAKE,
dd0e545f	19	TRACE_CONT,
72829bc3	20	TRACE_STACK,
dd0e545f	21	TRACE_PRINT,
72829bc3	22	TRACE_SPECIAL,
bd8ac686 PP	23	TRACE_MMIO_RW,
bd8ac686 PP	24	TRACE_MMIO_MAP,
9f029e83	25	TRACE_BRANCH,
74239072 FW	26	TRACE_BOOT_CALL,
74239072 FW	27	TRACE_BOOT_RET,
15e6cb36	28	TRACE_FN_RET,
72829bc3 TG	29
	30	__TRACE_LAST_TYPE
	31	};
	32
777e208d SR	33	/*
	34	* The trace entry - the most basic unit of tracing. This is what
	35	* is printed in the end as a single line in the trace output, such as:
	36	*
	37	* bash-15816 [01] 235.197585: idle_cpu <- irq_enter
	38	*/
	39	struct trace_entry {
	40	unsigned char type;
	41	unsigned char cpu;
	42	unsigned char flags;
	43	unsigned char preempt_count;
	44	int pid;
	45	};
	46
bc0c38d1 SR	47	/*
	48	* Function trace entry - function address and parent function addres:
	49	*/
	50	struct ftrace_entry {
777e208d	51	struct trace_entry ent;
bc0c38d1 SR	52	unsigned long ip;
	53	unsigned long parent_ip;
	54	};
15e6cb36 FW	55
	56	/* Function return entry */
	57	struct ftrace_ret_entry {
	58	struct trace_entry ent;
	59	unsigned long ip;
	60	unsigned long parent_ip;
	61	unsigned long long calltime;
	62	unsigned long long rettime;
0231022c	63	unsigned long overrun;
15e6cb36	64	};
d13744cd	65	extern struct tracer boot_tracer;
bc0c38d1 SR	66
	67	/*
	68	* Context switch trace entry - which task (and prio) we switched from/to:
	69	*/
	70	struct ctx_switch_entry {
777e208d	71	struct trace_entry ent;
bc0c38d1 SR	72	unsigned int prev_pid;
	73	unsigned char prev_prio;
	74	unsigned char prev_state;
	75	unsigned int next_pid;
	76	unsigned char next_prio;
bac524d3	77	unsigned char next_state;
80b5e940	78	unsigned int next_cpu;
bc0c38d1 SR	79	};
bc0c38d1 SR	80
f0a920d5 IM	81	/*
	82	* Special (free-form) trace entry:
	83	*/
	84	struct special_entry {
777e208d	85	struct trace_entry ent;
f0a920d5 IM	86	unsigned long arg1;
	87	unsigned long arg2;
	88	unsigned long arg3;
	89	};
	90
86387f7e IM	91	/*
	92	* Stack-trace entry:
	93	*/
	94
74f4e369	95	#define FTRACE_STACK_ENTRIES 8
86387f7e IM	96
86387f7e IM	97	struct stack_entry {
777e208d	98	struct trace_entry ent;
86387f7e IM	99	unsigned long caller[FTRACE_STACK_ENTRIES];
	100	};
	101
dd0e545f SR	102	/*
	103	* ftrace_printk entry:
	104	*/
	105	struct print_entry {
777e208d	106	struct trace_entry ent;
dd0e545f SR	107	unsigned long ip;
	108	char buf[];
	109	};
	110
777e208d SR	111	#define TRACE_OLD_SIZE 88
	112
	113	struct trace_field_cont {
	114	unsigned char type;
	115	/* Temporary till we get rid of this completely */
	116	char buf[TRACE_OLD_SIZE - 1];
	117	};
	118
	119	struct trace_mmiotrace_rw {
	120	struct trace_entry ent;
	121	struct mmiotrace_rw rw;
	122	};
	123
	124	struct trace_mmiotrace_map {
	125	struct trace_entry ent;
	126	struct mmiotrace_map map;
	127	};
	128
74239072	129	struct trace_boot_call {
777e208d	130	struct trace_entry ent;
74239072 FW	131	struct boot_trace_call boot_call;
	132	};
	133
	134	struct trace_boot_ret {
	135	struct trace_entry ent;
	136	struct boot_trace_ret boot_ret;
777e208d SR	137	};
777e208d SR	138
52f232cb SR	139	#define TRACE_FUNC_SIZE 30
52f232cb SR	140	#define TRACE_FILE_SIZE 20
9f029e83	141	struct trace_branch {
52f232cb SR	142	struct trace_entry ent;
	143	unsigned line;
	144	char func[TRACE_FUNC_SIZE+1];
	145	char file[TRACE_FILE_SIZE+1];
	146	char correct;
	147	};
	148
fc5e27ae PP	149	/*
	150	* trace_flag_type is an enumeration that holds different
	151	* states when a trace occurs. These are:
9244489a SR	152	* IRQS_OFF - interrupts were disabled
	153	* IRQS_NOSUPPORT - arch does not support irqs_disabled_flags
	154	* NEED_RESCED - reschedule is requested
	155	* HARDIRQ - inside an interrupt handler
	156	* SOFTIRQ - inside a softirq handler
	157	* CONT - multiple entries hold the trace item
fc5e27ae PP	158	*/
	159	enum trace_flag_type {
	160	TRACE_FLAG_IRQS_OFF = 0x01,
9244489a SR	161	TRACE_FLAG_IRQS_NOSUPPORT = 0x02,
	162	TRACE_FLAG_NEED_RESCHED = 0x04,
	163	TRACE_FLAG_HARDIRQ = 0x08,
	164	TRACE_FLAG_SOFTIRQ = 0x10,
	165	TRACE_FLAG_CONT = 0x20,
fc5e27ae PP	166	};
fc5e27ae PP	167
5bf9a1ee	168	#define TRACE_BUF_SIZE 1024
bc0c38d1 SR	169
	170	/*
	171	* The CPU trace array - it consists of thousands of trace entries
	172	* plus some other descriptor data: (for example which task started
	173	* the trace, etc.)
	174	*/
	175	struct trace_array_cpu {
bc0c38d1	176	atomic_t disabled;
4e3c3333	177
c7aafc54	178	/* these fields get copied into max-trace: */
c7aafc54	179	unsigned long trace_idx;
53d0aa77	180	unsigned long overrun;
bc0c38d1 SR	181	unsigned long saved_latency;
	182	unsigned long critical_start;
	183	unsigned long critical_end;
	184	unsigned long critical_sequence;
	185	unsigned long nice;
	186	unsigned long policy;
	187	unsigned long rt_priority;
	188	cycle_t preempt_timestamp;
	189	pid_t pid;
	190	uid_t uid;
	191	char comm[TASK_COMM_LEN];
	192	};
	193
	194	struct trace_iterator;
	195
	196	/*
	197	* The trace array - an array of per-CPU trace arrays. This is the
	198	* highest level data structure that individual tracers deal with.
	199	* They have on/off state as well:
	200	*/
	201	struct trace_array {
3928a8a2	202	struct ring_buffer *buffer;
bc0c38d1	203	unsigned long entries;
bc0c38d1 SR	204	int cpu;
bc0c38d1 SR	205	cycle_t time_start;
b3806b43	206	struct task_struct *waiter;
bc0c38d1 SR	207	struct trace_array_cpu *data[NR_CPUS];
	208	};
	209
7104f300 SR	210	#define FTRACE_CMP_TYPE(var, type) \
	211	__builtin_types_compatible_p(typeof(var), type *)
	212
	213	#undef IF_ASSIGN
	214	#define IF_ASSIGN(var, entry, etype, id) \
	215	if (FTRACE_CMP_TYPE(var, etype)) { \
	216	var = (typeof(var))(entry); \
	217	WARN_ON(id && (entry)->type != id); \
	218	break; \
	219	}
	220
	221	/* Will cause compile errors if type is not found. */
	222	extern void __ftrace_bad_type(void);
	223
	224	/*
	225	* The trace_assign_type is a verifier that the entry type is
	226	* the same as the type being assigned. To add new types simply
	227	* add a line with the following format:
	228	*
	229	* IF_ASSIGN(var, ent, type, id);
	230	*
	231	* Where "type" is the trace type that includes the trace_entry
	232	* as the "ent" item. And "id" is the trace identifier that is
	233	* used in the trace_type enum.
	234	*
	235	* If the type can have more than one id, then use zero.
	236	*/
	237	#define trace_assign_type(var, ent) \
	238	do { \
	239	IF_ASSIGN(var, ent, struct ftrace_entry, TRACE_FN); \
	240	IF_ASSIGN(var, ent, struct ctx_switch_entry, 0); \
	241	IF_ASSIGN(var, ent, struct trace_field_cont, TRACE_CONT); \
	242	IF_ASSIGN(var, ent, struct stack_entry, TRACE_STACK); \
	243	IF_ASSIGN(var, ent, struct print_entry, TRACE_PRINT); \
	244	IF_ASSIGN(var, ent, struct special_entry, 0); \
	245	IF_ASSIGN(var, ent, struct trace_mmiotrace_rw, \
	246	TRACE_MMIO_RW); \
	247	IF_ASSIGN(var, ent, struct trace_mmiotrace_map, \
	248	TRACE_MMIO_MAP); \
74239072 FW	249	IF_ASSIGN(var, ent, struct trace_boot_call, TRACE_BOOT_CALL);\
74239072 FW	250	IF_ASSIGN(var, ent, struct trace_boot_ret, TRACE_BOOT_RET);\
9f029e83	251	IF_ASSIGN(var, ent, struct trace_branch, TRACE_BRANCH); \
74239072	252	IF_ASSIGN(var, ent, struct ftrace_ret_entry, TRACE_FN_RET);\
7104f300 SR	253	__ftrace_bad_type(); \
7104f300 SR	254	} while (0)
2c4f035f FW	255
	256	/* Return values for print_line callback */
	257	enum print_line_t {
	258	TRACE_TYPE_PARTIAL_LINE = 0, /* Retry after flushing the seq */
	259	TRACE_TYPE_HANDLED = 1,
	260	TRACE_TYPE_UNHANDLED = 2 /* Relay to other output functions */
	261	};
	262
adf9f195 FW	263
	264	/*
	265	* An option specific to a tracer. This is a boolean value.
	266	* The bit is the bit index that sets its value on the
	267	* flags value in struct tracer_flags.
	268	*/
	269	struct tracer_opt {
	270	const char name; / Will appear on the trace_options file */
	271	u32 bit; /* Mask assigned in val field in tracer_flags */
	272	};
	273
	274	/*
	275	* The set of specific options for a tracer. Your tracer
	276	* have to set the initial value of the flags val.
	277	*/
	278	struct tracer_flags {
	279	u32 val;
	280	struct tracer_opt *opts;
	281	};
	282
	283	/* Makes more easy to define a tracer opt */
	284	#define TRACER_OPT(s, b) .name = #s, .bit = b
	285
bc0c38d1 SR	286	/*
	287	* A specific tracer, represented by methods that operate on a trace array:
	288	*/
	289	struct tracer {
	290	const char *name;
1c80025a FW	291	/* Your tracer should raise a warning if init fails */
1c80025a FW	292	int (init)(struct trace_array tr);
bc0c38d1	293	void (reset)(struct trace_array tr);
9036990d SR	294	void (start)(struct trace_array tr);
9036990d SR	295	void (stop)(struct trace_array tr);
bc0c38d1	296	void (open)(struct trace_iterator iter);
107bad8b	297	void (pipe_open)(struct trace_iterator iter);
bc0c38d1	298	void (close)(struct trace_iterator iter);
107bad8b SR	299	ssize_t (read)(struct trace_iterator iter,
	300	struct file filp, char __user ubuf,
	301	size_t cnt, loff_t *ppos);
60a11774 SR	302	#ifdef CONFIG_FTRACE_STARTUP_TEST
	303	int (selftest)(struct tracer trace,
	304	struct trace_array *tr);
	305	#endif
2c4f035f	306	enum print_line_t (print_line)(struct trace_iterator iter);
adf9f195 FW	307	/* If you handled the flag setting, return 0 */
adf9f195 FW	308	int (*set_flag)(u32 old_flags, u32 bit, int set);
bc0c38d1 SR	309	struct tracer *next;
bc0c38d1 SR	310	int print_max;
adf9f195	311	struct tracer_flags *flags;
bc0c38d1 SR	312	};
bc0c38d1 SR	313
214023c3 SR	314	struct trace_seq {
	315	unsigned char buffer[PAGE_SIZE];
	316	unsigned int len;
6c6c2796	317	unsigned int readpos;
214023c3 SR	318	};
214023c3 SR	319
bc0c38d1 SR	320	/*
	321	* Trace iterator - used by printout routines who present trace
	322	* results to users and which routines might sleep, etc:
	323	*/
	324	struct trace_iterator {
	325	struct trace_array *tr;
	326	struct tracer *trace;
107bad8b	327	void *private;
3928a8a2	328	struct ring_buffer_iter *buffer_iter[NR_CPUS];
4e3c3333	329
53d0aa77 SR	330	/* The below is zeroed out in pipe_read */
53d0aa77 SR	331	struct trace_seq seq;
bc0c38d1	332	struct trace_entry *ent;
4e3c3333	333	int cpu;
3928a8a2	334	u64 ts;
4e3c3333	335
bc0c38d1 SR	336	unsigned long iter_flags;
bc0c38d1 SR	337	loff_t pos;
4c11d7ae	338	long idx;
a309720c SR	339
a309720c SR	340	cpumask_t started;
bc0c38d1 SR	341	};
bc0c38d1 SR	342
9036990d	343	int tracing_is_enabled(void);
45dcd8b8	344	void trace_wake_up(void);
3928a8a2	345	void tracing_reset(struct trace_array *tr, int cpu);
bc0c38d1 SR	346	int tracing_open_generic(struct inode inode, struct file filp);
bc0c38d1 SR	347	struct dentry *tracing_init_dentry(void);
d618b3e6 IM	348	void init_tracer_sysprof_debugfs(struct dentry *d_tracer);
d618b3e6 IM	349
45dcd8b8 PP	350	struct trace_entry tracing_get_trace_entry(struct trace_array tr,
	351	struct trace_array_cpu *data);
	352	void tracing_generic_entry_update(struct trace_entry *entry,
38697053 SR	353	unsigned long flags,
38697053 SR	354	int pc);
45dcd8b8	355
bc0c38d1 SR	356	void ftrace(struct trace_array *tr,
	357	struct trace_array_cpu *data,
	358	unsigned long ip,
	359	unsigned long parent_ip,
38697053	360	unsigned long flags, int pc);
bc0c38d1 SR	361	void tracing_sched_switch_trace(struct trace_array *tr,
	362	struct trace_array_cpu *data,
	363	struct task_struct *prev,
	364	struct task_struct *next,
38697053	365	unsigned long flags, int pc);
bc0c38d1	366	void tracing_record_cmdline(struct task_struct *tsk);
57422797 IM	367
	368	void tracing_sched_wakeup_trace(struct trace_array *tr,
	369	struct trace_array_cpu *data,
	370	struct task_struct *wakee,
	371	struct task_struct *cur,
38697053	372	unsigned long flags, int pc);
f0a920d5 IM	373	void trace_special(struct trace_array *tr,
	374	struct trace_array_cpu *data,
	375	unsigned long arg1,
	376	unsigned long arg2,
38697053	377	unsigned long arg3, int pc);
6fb44b71 SR	378	void trace_function(struct trace_array *tr,
	379	struct trace_array_cpu *data,
	380	unsigned long ip,
	381	unsigned long parent_ip,
38697053	382	unsigned long flags, int pc);
15e6cb36 FW	383	void
15e6cb36 FW	384	trace_function_return(struct ftrace_retfunc *trace);
bc0c38d1	385
41bc8144 SR	386	void tracing_start_cmdline_record(void);
41bc8144 SR	387	void tracing_stop_cmdline_record(void);
e168e051 SR	388	void tracing_sched_switch_assign_trace(struct trace_array *tr);
	389	void tracing_stop_sched_switch_record(void);
	390	void tracing_start_sched_switch_record(void);
bc0c38d1 SR	391	int register_tracer(struct tracer *type);
	392	void unregister_tracer(struct tracer *type);
	393
	394	extern unsigned long nsecs_to_usecs(unsigned long nsecs);
	395
	396	extern unsigned long tracing_max_latency;
	397	extern unsigned long tracing_thresh;
	398
	399	void update_max_tr(struct trace_array tr, struct task_struct tsk, int cpu);
	400	void update_max_tr_single(struct trace_array *tr,
	401	struct task_struct *tsk, int cpu);
	402
e309b41d	403	extern cycle_t ftrace_now(int cpu);
bc0c38d1	404
606576ce	405	#ifdef CONFIG_FUNCTION_TRACER
001b6767 SR	406	void tracing_start_function_trace(void);
	407	void tracing_stop_function_trace(void);
	408	#else
	409	# define tracing_start_function_trace() do { } while (0)
	410	# define tracing_stop_function_trace() do { } while (0)
	411	#endif
	412
bc0c38d1 SR	413	#ifdef CONFIG_CONTEXT_SWITCH_TRACER
	414	typedef void
	415	(tracer_switch_func_t)(void private,
5b82a1b0	416	void *__rq,
bc0c38d1 SR	417	struct task_struct *prev,
	418	struct task_struct *next);
	419
	420	struct tracer_switch_ops {
	421	tracer_switch_func_t func;
	422	void *private;
	423	struct tracer_switch_ops *next;
	424	};
	425
bc0c38d1 SR	426	#endif /* CONFIG_CONTEXT_SWITCH_TRACER */
	427
	428	#ifdef CONFIG_DYNAMIC_FTRACE
	429	extern unsigned long ftrace_update_tot_cnt;
d05cdb25 SR	430	#define DYN_FTRACE_TEST_NAME trace_selftest_dynamic_test_func
d05cdb25 SR	431	extern int DYN_FTRACE_TEST_NAME(void);
bc0c38d1 SR	432	#endif
bc0c38d1 SR	433
60a11774	434	#ifdef CONFIG_FTRACE_STARTUP_TEST
60a11774 SR	435	extern int trace_selftest_startup_function(struct tracer *trace,
60a11774 SR	436	struct trace_array *tr);
60a11774 SR	437	extern int trace_selftest_startup_irqsoff(struct tracer *trace,
60a11774 SR	438	struct trace_array *tr);
60a11774 SR	439	extern int trace_selftest_startup_preemptoff(struct tracer *trace,
60a11774 SR	440	struct trace_array *tr);
60a11774 SR	441	extern int trace_selftest_startup_preemptirqsoff(struct tracer *trace,
60a11774 SR	442	struct trace_array *tr);
60a11774 SR	443	extern int trace_selftest_startup_wakeup(struct tracer *trace,
60a11774 SR	444	struct trace_array *tr);
fb1b6d8b SN	445	extern int trace_selftest_startup_nop(struct tracer *trace,
fb1b6d8b SN	446	struct trace_array *tr);
60a11774 SR	447	extern int trace_selftest_startup_sched_switch(struct tracer *trace,
60a11774 SR	448	struct trace_array *tr);
a6dd24f8 IM	449	extern int trace_selftest_startup_sysprof(struct tracer *trace,
a6dd24f8 IM	450	struct trace_array *tr);
80e5ea45 SR	451	extern int trace_selftest_startup_branch(struct tracer *trace,
80e5ea45 SR	452	struct trace_array *tr);
60a11774 SR	453	#endif /* CONFIG_FTRACE_STARTUP_TEST */
60a11774 SR	454
c7aafc54	455	extern void head_page(struct trace_array_cpu data);
72829bc3	456	extern int trace_seq_printf(struct trace_seq s, const char fmt, ...);
fc5e27ae PP	457	extern void trace_seq_print_cont(struct trace_seq *s,
fc5e27ae PP	458	struct trace_iterator *iter);
15e6cb36 FW	459
	460	extern int
	461	seq_print_ip_sym(struct trace_seq *s, unsigned long ip,
	462	unsigned long sym_flags);
6c6c2796 PP	463	extern ssize_t trace_seq_to_user(struct trace_seq s, char __user ubuf,
6c6c2796 PP	464	size_t cnt);
72829bc3	465	extern long ns2usecs(cycle_t nsec);
801fe400	466	extern int trace_vprintk(unsigned long ip, const char *fmt, va_list args);
c7aafc54	467
4e655519 IM	468	extern unsigned long trace_flags;
4e655519 IM	469
15e6cb36 FW	470	/* Standard output formatting function used for function return traces */
	471	#ifdef CONFIG_FUNCTION_RET_TRACER
	472	extern enum print_line_t print_return_function(struct trace_iterator *iter);
	473	#else
	474	static inline enum print_line_t
	475	print_return_function(struct trace_iterator *iter)
	476	{
	477	return TRACE_TYPE_UNHANDLED;
	478	}
	479	#endif
	480
4fcdae83 SR	481	/*
	482	* trace_iterator_flags is an enumeration that defines bit
	483	* positions into trace_flags that controls the output.
	484	*
	485	* NOTE: These bits must match the trace_options array in
	486	* trace.c.
	487	*/
4e655519 IM	488	enum trace_iterator_flags {
	489	TRACE_ITER_PRINT_PARENT = 0x01,
	490	TRACE_ITER_SYM_OFFSET = 0x02,
	491	TRACE_ITER_SYM_ADDR = 0x04,
	492	TRACE_ITER_VERBOSE = 0x08,
	493	TRACE_ITER_RAW = 0x10,
	494	TRACE_ITER_HEX = 0x20,
	495	TRACE_ITER_BIN = 0x40,
	496	TRACE_ITER_BLOCK = 0x80,
	497	TRACE_ITER_STACKTRACE = 0x100,
4ac3ba41	498	TRACE_ITER_SCHED_TREE = 0x200,
f09ce573	499	TRACE_ITER_PRINTK = 0x400,
b2a866f9	500	TRACE_ITER_PREEMPTONLY = 0x800,
9f029e83	501	TRACE_ITER_BRANCH = 0x1000,
12ef7d44	502	TRACE_ITER_ANNOTATE = 0x2000,
4e655519 IM	503	};
4e655519 IM	504
15e6cb36 FW	505	/*
	506	* TRACE_ITER_SYM_MASK masks the options in trace_flags that
	507	* control the output of kernel symbols.
	508	*/
	509	#define TRACE_ITER_SYM_MASK \
	510	(TRACE_ITER_PRINT_PARENT\|TRACE_ITER_SYM_OFFSET\|TRACE_ITER_SYM_ADDR)
	511
43a15386 FW	512	extern struct tracer nop_trace;
43a15386 FW	513
8f0a056f SR	514	/**
	515	* ftrace_preempt_disable - disable preemption scheduler safe
	516	*
	517	* When tracing can happen inside the scheduler, there exists
	518	* cases that the tracing might happen before the need_resched
	519	* flag is checked. If this happens and the tracer calls
	520	* preempt_enable (after a disable), a schedule might take place
	521	* causing an infinite recursion.
	522	*
	523	* To prevent this, we read the need_recshed flag before
	524	* disabling preemption. When we want to enable preemption we
	525	* check the flag, if it is set, then we call preempt_enable_no_resched.
	526	* Otherwise, we call preempt_enable.
	527	*
	528	* The rational for doing the above is that if need resched is set
	529	* and we have yet to reschedule, we are either in an atomic location
	530	* (where we do not need to check for scheduling) or we are inside
	531	* the scheduler and do not want to resched.
	532	*/
	533	static inline int ftrace_preempt_disable(void)
	534	{
	535	int resched;
	536
	537	resched = need_resched();
	538	preempt_disable_notrace();
	539
	540	return resched;
	541	}
	542
	543	/**
	544	* ftrace_preempt_enable - enable preemption scheduler safe
	545	* @resched: the return value from ftrace_preempt_disable
	546	*
	547	* This is a scheduler safe way to enable preemption and not miss
	548	* any preemption checks. The disabled saved the state of preemption.
	549	* If resched is set, then we were either inside an atomic or
	550	* are inside the scheduler (we would have already scheduled
	551	* otherwise). In this case, we do not want to call normal
	552	* preempt_enable, but preempt_enable_no_resched instead.
	553	*/
	554	static inline void ftrace_preempt_enable(int resched)
	555	{
	556	if (resched)
	557	preempt_enable_no_resched_notrace();
	558	else
	559	preempt_enable_notrace();
	560	}
	561
2ed84eeb	562	#ifdef CONFIG_BRANCH_TRACER
9f029e83 SR	563	extern int enable_branch_tracing(struct trace_array *tr);
	564	extern void disable_branch_tracing(void);
	565	static inline int trace_branch_enable(struct trace_array *tr)
52f232cb	566	{
9f029e83 SR	567	if (trace_flags & TRACE_ITER_BRANCH)
9f029e83 SR	568	return enable_branch_tracing(tr);
52f232cb SR	569	return 0;
52f232cb SR	570	}
9f029e83	571	static inline void trace_branch_disable(void)
52f232cb SR	572	{
52f232cb SR	573	/* due to races, always disable */
9f029e83	574	disable_branch_tracing();
52f232cb SR	575	}
52f232cb SR	576	#else
9f029e83	577	static inline int trace_branch_enable(struct trace_array *tr)
52f232cb SR	578	{
	579	return 0;
	580	}
9f029e83	581	static inline void trace_branch_disable(void)
52f232cb SR	582	{
52f232cb SR	583	}
2ed84eeb	584	#endif /* CONFIG_BRANCH_TRACER */
52f232cb	585
bc0c38d1	586	#endif /* _LINUX_KERNEL_TRACE_H */