linux-stable/include/linux/seq_buf.h
Piotr Maziarz 353cade314 seq_buf: Add printing formatted hex dumps
Provided function is an analogue of print_hex_dump().

Implementing this function in seq_buf allows using for multiple
purposes (e.g. for tracing) and therefore prevents from code duplication
in every layer that uses seq_buf.

print_hex_dump() is an essential part of logging data to dmesg. Adding
similar capability for other purposes is beneficial to all users.

Example usage:
seq_buf_hex_dump(seq, "", DUMP_PREFIX_OFFSET, 16, 4, buf,
		 ARRAY_SIZE(buf), true);
Example output:
00000000: 00000000 ffffff10 ffffff32 ffff3210  ........2....2..
00000010: ffff3210 83d00437 c0700000 00000000  .2..7.....p.....
00000020: 02010004 0000000f 0000000f 00004002  .............@..
00000030: 00000fff 00000000                    ........

Link: http://lkml.kernel.org/r/1573130738-29390-1-git-send-email-piotrx.maziarz@linux.intel.com

Signed-off-by: Piotr Maziarz <piotrx.maziarz@linux.intel.com>
Signed-off-by: Cezary Rojewski <cezary.rojewski@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-11-14 13:15:12 -05:00

137 lines
3.3 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_SEQ_BUF_H
#define _LINUX_SEQ_BUF_H
#include <linux/fs.h>
/*
* Trace sequences are used to allow a function to call several other functions
* to create a string of data to use.
*/
/**
* seq_buf - seq buffer structure
* @buffer: pointer to the buffer
* @size: size of the buffer
* @len: the amount of data inside the buffer
* @readpos: The next position to read in the buffer.
*/
struct seq_buf {
char *buffer;
size_t size;
size_t len;
loff_t readpos;
};
static inline void seq_buf_clear(struct seq_buf *s)
{
s->len = 0;
s->readpos = 0;
}
static inline void
seq_buf_init(struct seq_buf *s, unsigned char *buf, unsigned int size)
{
s->buffer = buf;
s->size = size;
seq_buf_clear(s);
}
/*
* seq_buf have a buffer that might overflow. When this happens
* the len and size are set to be equal.
*/
static inline bool
seq_buf_has_overflowed(struct seq_buf *s)
{
return s->len > s->size;
}
static inline void
seq_buf_set_overflow(struct seq_buf *s)
{
s->len = s->size + 1;
}
/*
* How much buffer is left on the seq_buf?
*/
static inline unsigned int
seq_buf_buffer_left(struct seq_buf *s)
{
if (seq_buf_has_overflowed(s))
return 0;
return s->size - s->len;
}
/* How much buffer was written? */
static inline unsigned int seq_buf_used(struct seq_buf *s)
{
return min(s->len, s->size);
}
/**
* seq_buf_get_buf - get buffer to write arbitrary data to
* @s: the seq_buf handle
* @bufp: the beginning of the buffer is stored here
*
* Return the number of bytes available in the buffer, or zero if
* there's no space.
*/
static inline size_t seq_buf_get_buf(struct seq_buf *s, char **bufp)
{
WARN_ON(s->len > s->size + 1);
if (s->len < s->size) {
*bufp = s->buffer + s->len;
return s->size - s->len;
}
*bufp = NULL;
return 0;
}
/**
* seq_buf_commit - commit data to the buffer
* @s: the seq_buf handle
* @num: the number of bytes to commit
*
* Commit @num bytes of data written to a buffer previously acquired
* by seq_buf_get. To signal an error condition, or that the data
* didn't fit in the available space, pass a negative @num value.
*/
static inline void seq_buf_commit(struct seq_buf *s, int num)
{
if (num < 0) {
seq_buf_set_overflow(s);
} else {
/* num must be negative on overflow */
BUG_ON(s->len + num > s->size);
s->len += num;
}
}
extern __printf(2, 3)
int seq_buf_printf(struct seq_buf *s, const char *fmt, ...);
extern __printf(2, 0)
int seq_buf_vprintf(struct seq_buf *s, const char *fmt, va_list args);
extern int seq_buf_print_seq(struct seq_file *m, struct seq_buf *s);
extern int seq_buf_to_user(struct seq_buf *s, char __user *ubuf,
int cnt);
extern int seq_buf_puts(struct seq_buf *s, const char *str);
extern int seq_buf_putc(struct seq_buf *s, unsigned char c);
extern int seq_buf_putmem(struct seq_buf *s, const void *mem, unsigned int len);
extern int seq_buf_putmem_hex(struct seq_buf *s, const void *mem,
unsigned int len);
extern int seq_buf_path(struct seq_buf *s, const struct path *path, const char *esc);
extern int seq_buf_hex_dump(struct seq_buf *s, const char *prefix_str,
int prefix_type, int rowsize, int groupsize,
const void *buf, size_t len, bool ascii);
#ifdef CONFIG_BINARY_PRINTF
extern int
seq_buf_bprintf(struct seq_buf *s, const char *fmt, const u32 *binary);
#endif
#endif /* _LINUX_SEQ_BUF_H */