1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
|
/* 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
*/
struct seq_buf {
char *buffer;
size_t size;
size_t len;
};
#define DECLARE_SEQ_BUF(NAME, SIZE) \
char __ ## NAME ## _buffer[SIZE] = ""; \
struct seq_buf NAME = { \
.buffer = &__ ## NAME ## _buffer, \
.size = SIZE, \
}
static inline void seq_buf_clear(struct seq_buf *s)
{
s->len = 0;
if (s->size)
s->buffer[0] = '\0';
}
static inline void
seq_buf_init(struct seq_buf *s, 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
* len is set to be greater than size.
*/
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_str - get %NUL-terminated C string from seq_buf
* @s: the seq_buf handle
*
* This makes sure that the buffer in @s is nul terminated and
* safe to read as a string.
*
* Note, if this is called when the buffer has overflowed, then
* the last byte of the buffer is zeroed, and the len will still
* point passed it.
*
* After this function is called, s->buffer is safe to use
* in string operations.
*
* Returns @s->buf after making sure it is terminated.
*/
static inline const char *seq_buf_str(struct seq_buf *s)
{
if (WARN_ON(s->size == 0))
return "";
if (seq_buf_buffer_left(s))
s->buffer[s->len] = 0;
else
s->buffer[s->size - 1] = 0;
return s->buffer;
}
/**
* 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,
size_t start, 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
void seq_buf_do_printk(struct seq_buf *s, const char *lvl);
#endif /* _LINUX_SEQ_BUF_H */
|
