[mirror_ubuntu-bionic-kernel.git] / include / linux / trace_seq.h

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_TRACE_SEQ_H
#define _LINUX_TRACE_SEQ_H

#include <linux/seq_buf.h>

#include <asm/page.h>

/*
 * Trace sequences are used to allow a function to call several other functions
 * to create a string of data to use (up to a max of PAGE_SIZE).
 */

struct trace_seq {
	unsigned char		buffer[PAGE_SIZE];
	struct seq_buf		seq;
	int			full;
};

static inline void
trace_seq_init(struct trace_seq *s)
{
	seq_buf_init(&s->seq, s->buffer, PAGE_SIZE);
	s->full = 0;
}

/**
 * trace_seq_used - amount of actual data written to buffer
 * @s: trace sequence descriptor
 *
 * Returns the amount of data written to the buffer.
 *
 * IMPORTANT!
 *
 * Use this instead of @s->seq.len if you need to pass the amount
 * of data from the buffer to another buffer (userspace, or what not).
 * The @s->seq.len on overflow is bigger than the buffer size and
 * using it can cause access to undefined memory.
 */
static inline int trace_seq_used(struct trace_seq *s)
{
	return seq_buf_used(&s->seq);
}

/**
 * trace_seq_buffer_ptr - return pointer to next location in buffer
 * @s: trace sequence descriptor
 *
 * Returns the pointer to the buffer where the next write to
 * the buffer will happen. This is useful to save the location
 * that is about to be written to and then return the result
 * of that write.
 */
static inline unsigned char *
trace_seq_buffer_ptr(struct trace_seq *s)
{
	return s->buffer + seq_buf_used(&s->seq);
}

/**
 * trace_seq_has_overflowed - return true if the trace_seq took too much
 * @s: trace sequence descriptor
 *
 * Returns true if too much data was added to the trace_seq and it is
 * now full and will not take anymore.
 */
static inline bool trace_seq_has_overflowed(struct trace_seq *s)
{
	return s->full || seq_buf_has_overflowed(&s->seq);
}

/*
 * Currently only defined when tracing is enabled.
 */
#ifdef CONFIG_TRACING
extern __printf(2, 3)
void trace_seq_printf(struct trace_seq *s, const char *fmt, ...);
extern __printf(2, 0)
void trace_seq_vprintf(struct trace_seq *s, const char *fmt, va_list args);
extern void
trace_seq_bprintf(struct trace_seq *s, const char *fmt, const u32 *binary);
extern int trace_print_seq(struct seq_file *m, struct trace_seq *s);
extern int trace_seq_to_user(struct trace_seq *s, char __user *ubuf,
			     int cnt);
extern void trace_seq_puts(struct trace_seq *s, const char *str);
extern void trace_seq_putc(struct trace_seq *s, unsigned char c);
extern void trace_seq_putmem(struct trace_seq *s, const void *mem, unsigned int len);
extern void trace_seq_putmem_hex(struct trace_seq *s, const void *mem,
				unsigned int len);
extern int trace_seq_path(struct trace_seq *s, const struct path *path);

extern void trace_seq_bitmask(struct trace_seq *s, const unsigned long *maskp,
			     int nmaskbits);

#else /* CONFIG_TRACING */
static inline void trace_seq_printf(struct trace_seq *s, const char *fmt, ...)
{
}
static inline void
trace_seq_bprintf(struct trace_seq *s, const char *fmt, const u32 *binary)
{
}

static inline void
trace_seq_bitmask(struct trace_seq *s, const unsigned long *maskp,
		  int nmaskbits)
{
}

static inline int trace_print_seq(struct seq_file *m, struct trace_seq *s)
{
	return 0;
}
static inline int trace_seq_to_user(struct trace_seq *s, char __user *ubuf,
				    int cnt)
{
	return 0;
}
static inline void trace_seq_puts(struct trace_seq *s, const char *str)
{
}
static inline void trace_seq_putc(struct trace_seq *s, unsigned char c)
{
}
static inline void
trace_seq_putmem(struct trace_seq *s, const void *mem, unsigned int len)
{
}
static inline void trace_seq_putmem_hex(struct trace_seq *s, const void *mem,
				       unsigned int len)
{
}
static inline int trace_seq_path(struct trace_seq *s, const struct path *path)
{
	return 0;
}
#endif /* CONFIG_TRACING */

#endif /* _LINUX_TRACE_SEQ_H */
Commit	Line	Data
	1	/* SPDX-License-Identifier: GPL-2.0 */
	2	#ifndef _LINUX_TRACE_SEQ_H
	3	#define _LINUX_TRACE_SEQ_H
	4
	5	#include <linux/seq_buf.h>
	6
	7	#include <asm/page.h>
	8
	9	/*
	10	* Trace sequences are used to allow a function to call several other functions
	11	* to create a string of data to use (up to a max of PAGE_SIZE).
	12	*/
	13
	14	struct trace_seq {
	15	unsigned char buffer[PAGE_SIZE];
	16	struct seq_buf seq;
	17	int full;
	18	};
	19
	20	static inline void
	21	trace_seq_init(struct trace_seq *s)
	22	{
	23	seq_buf_init(&s->seq, s->buffer, PAGE_SIZE);
	24	s->full = 0;
	25	}
	26
	27	/**
	28	* trace_seq_used - amount of actual data written to buffer
	29	* @s: trace sequence descriptor
	30	*
	31	* Returns the amount of data written to the buffer.
	32	*
	33	* IMPORTANT!
	34	*
	35	* Use this instead of @s->seq.len if you need to pass the amount
	36	* of data from the buffer to another buffer (userspace, or what not).
	37	* The @s->seq.len on overflow is bigger than the buffer size and
	38	* using it can cause access to undefined memory.
	39	*/
	40	static inline int trace_seq_used(struct trace_seq *s)
	41	{
	42	return seq_buf_used(&s->seq);
	43	}
	44
	45	/**
	46	* trace_seq_buffer_ptr - return pointer to next location in buffer
	47	* @s: trace sequence descriptor
	48	*
	49	* Returns the pointer to the buffer where the next write to
	50	* the buffer will happen. This is useful to save the location
	51	* that is about to be written to and then return the result
	52	* of that write.
	53	*/
	54	static inline unsigned char *
	55	trace_seq_buffer_ptr(struct trace_seq *s)
	56	{
	57	return s->buffer + seq_buf_used(&s->seq);
	58	}
	59
	60	/**
	61	* trace_seq_has_overflowed - return true if the trace_seq took too much
	62	* @s: trace sequence descriptor
	63	*
	64	* Returns true if too much data was added to the trace_seq and it is
	65	* now full and will not take anymore.
	66	*/
	67	static inline bool trace_seq_has_overflowed(struct trace_seq *s)
	68	{
	69	return s->full \|\| seq_buf_has_overflowed(&s->seq);
	70	}
	71
	72	/*
	73	* Currently only defined when tracing is enabled.
	74	*/
	75	#ifdef CONFIG_TRACING
	76	extern __printf(2, 3)
	77	void trace_seq_printf(struct trace_seq s, const char fmt, ...);
	78	extern __printf(2, 0)
	79	void trace_seq_vprintf(struct trace_seq s, const char fmt, va_list args);
	80	extern void
	81	trace_seq_bprintf(struct trace_seq s, const char fmt, const u32 *binary);
	82	extern int trace_print_seq(struct seq_file m, struct trace_seq s);
	83	extern int trace_seq_to_user(struct trace_seq s, char __user ubuf,
	84	int cnt);
	85	extern void trace_seq_puts(struct trace_seq s, const char str);
	86	extern void trace_seq_putc(struct trace_seq *s, unsigned char c);
	87	extern void trace_seq_putmem(struct trace_seq s, const void mem, unsigned int len);
	88	extern void trace_seq_putmem_hex(struct trace_seq s, const void mem,
	89	unsigned int len);
	90	extern int trace_seq_path(struct trace_seq s, const struct path path);
	91
	92	extern void trace_seq_bitmask(struct trace_seq s, const unsigned long maskp,
	93	int nmaskbits);
	94
	95	#else /* CONFIG_TRACING */
	96	static inline void trace_seq_printf(struct trace_seq s, const char fmt, ...)
	97	{
	98	}
	99	static inline void
	100	trace_seq_bprintf(struct trace_seq s, const char fmt, const u32 *binary)
	101	{
	102	}
	103
	104	static inline void
	105	trace_seq_bitmask(struct trace_seq s, const unsigned long maskp,
	106	int nmaskbits)
	107	{
	108	}
	109
	110	static inline int trace_print_seq(struct seq_file m, struct trace_seq s)
	111	{
	112	return 0;
	113	}
	114	static inline int trace_seq_to_user(struct trace_seq s, char __user ubuf,
	115	int cnt)
	116	{
	117	return 0;
	118	}
	119	static inline void trace_seq_puts(struct trace_seq s, const char str)
	120	{
	121	}
	122	static inline void trace_seq_putc(struct trace_seq *s, unsigned char c)
	123	{
	124	}
	125	static inline void
	126	trace_seq_putmem(struct trace_seq s, const void mem, unsigned int len)
	127	{
	128	}
	129	static inline void trace_seq_putmem_hex(struct trace_seq s, const void mem,
	130	unsigned int len)
	131	{
	132	}
	133	static inline int trace_seq_path(struct trace_seq s, const struct path path)
	134	{
	135	return 0;
	136	}
	137	#endif /* CONFIG_TRACING */
	138
	139	#endif /* _LINUX_TRACE_SEQ_H */