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1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef _LINUX_SEQ_FILE_H
3#define _LINUX_SEQ_FILE_H
4
5#include <linux/types.h>
6#include <linux/string.h>
7#include <linux/bug.h>
8#include <linux/mutex.h>
9#include <linux/cpumask.h>
10#include <linux/nodemask.h>
11#include <linux/fs.h>
12#include <linux/cred.h>
13
14struct seq_operations;
15
16struct seq_file {
17 char *buf;
18 size_t size;
19 size_t from;
20 size_t count;
21 size_t pad_until;
22 loff_t index;
23 loff_t read_pos;
24 struct mutex lock;
25 const struct seq_operations *op;
26 int poll_event;
27 const struct file *file;
28 void *private;
29};
30
31struct seq_operations {
32 void * (*start) (struct seq_file *m, loff_t *pos);
33 void (*stop) (struct seq_file *m, void *v);
34 void * (*next) (struct seq_file *m, void *v, loff_t *pos);
35 int (*show) (struct seq_file *m, void *v);
36};
37
38#define SEQ_SKIP 1
39
40/**
41 * seq_has_overflowed - check if the buffer has overflowed
42 * @m: the seq_file handle
43 *
44 * seq_files have a buffer which may overflow. When this happens a larger
45 * buffer is reallocated and all the data will be printed again.
46 * The overflow state is true when m->count == m->size.
47 *
48 * Returns true if the buffer received more than it can hold.
49 */
50static inline bool seq_has_overflowed(struct seq_file *m)
51{
52 return m->count == m->size;
53}
54
55/**
56 * seq_get_buf - get buffer to write arbitrary data to
57 * @m: the seq_file handle
58 * @bufp: the beginning of the buffer is stored here
59 *
60 * Return the number of bytes available in the buffer, or zero if
61 * there's no space.
62 */
63static inline size_t seq_get_buf(struct seq_file *m, char **bufp)
64{
65 BUG_ON(m->count > m->size);
66 if (m->count < m->size)
67 *bufp = m->buf + m->count;
68 else
69 *bufp = NULL;
70
71 return m->size - m->count;
72}
73
74/**
75 * seq_commit - commit data to the buffer
76 * @m: the seq_file handle
77 * @num: the number of bytes to commit
78 *
79 * Commit @num bytes of data written to a buffer previously acquired
80 * by seq_buf_get. To signal an error condition, or that the data
81 * didn't fit in the available space, pass a negative @num value.
82 */
83static inline void seq_commit(struct seq_file *m, int num)
84{
85 if (num < 0) {
86 m->count = m->size;
87 } else {
88 BUG_ON(m->count + num > m->size);
89 m->count += num;
90 }
91}
92
93/**
94 * seq_setwidth - set padding width
95 * @m: the seq_file handle
96 * @size: the max number of bytes to pad.
97 *
98 * Call seq_setwidth() for setting max width, then call seq_printf() etc. and
99 * finally call seq_pad() to pad the remaining bytes.
100 */
101static inline void seq_setwidth(struct seq_file *m, size_t size)
102{
103 m->pad_until = m->count + size;
104}
105void seq_pad(struct seq_file *m, char c);
106
107char *mangle_path(char *s, const char *p, const char *esc);
108int seq_open(struct file *, const struct seq_operations *);
109ssize_t seq_read(struct file *, char __user *, size_t, loff_t *);
110ssize_t seq_read_iter(struct kiocb *iocb, struct iov_iter *iter);
111loff_t seq_lseek(struct file *, loff_t, int);
112int seq_release(struct inode *, struct file *);
113int seq_write(struct seq_file *seq, const void *data, size_t len);
114
115__printf(2, 0)
116void seq_vprintf(struct seq_file *m, const char *fmt, va_list args);
117__printf(2, 3)
118void seq_printf(struct seq_file *m, const char *fmt, ...);
119void seq_putc(struct seq_file *m, char c);
120void seq_puts(struct seq_file *m, const char *s);
121void seq_put_decimal_ull_width(struct seq_file *m, const char *delimiter,
122 unsigned long long num, unsigned int width);
123void seq_put_decimal_ull(struct seq_file *m, const char *delimiter,
124 unsigned long long num);
125void seq_put_decimal_ll(struct seq_file *m, const char *delimiter, long long num);
126void seq_put_hex_ll(struct seq_file *m, const char *delimiter,
127 unsigned long long v, unsigned int width);
128
129void seq_escape_mem(struct seq_file *m, const char *src, size_t len,
130 unsigned int flags, const char *esc);
131
132static inline void seq_escape_str(struct seq_file *m, const char *src,
133 unsigned int flags, const char *esc)
134{
135 seq_escape_mem(m, src, strlen(src), flags, esc);
136}
137
138void seq_escape(struct seq_file *m, const char *s, const char *esc);
139
140void seq_hex_dump(struct seq_file *m, const char *prefix_str, int prefix_type,
141 int rowsize, int groupsize, const void *buf, size_t len,
142 bool ascii);
143
144int seq_path(struct seq_file *, const struct path *, const char *);
145int seq_file_path(struct seq_file *, struct file *, const char *);
146int seq_dentry(struct seq_file *, struct dentry *, const char *);
147int seq_path_root(struct seq_file *m, const struct path *path,
148 const struct path *root, const char *esc);
149
150int single_open(struct file *, int (*)(struct seq_file *, void *), void *);
151int single_open_size(struct file *, int (*)(struct seq_file *, void *), void *, size_t);
152int single_release(struct inode *, struct file *);
153void *__seq_open_private(struct file *, const struct seq_operations *, int);
154int seq_open_private(struct file *, const struct seq_operations *, int);
155int seq_release_private(struct inode *, struct file *);
156
157#ifdef CONFIG_BINARY_PRINTF
158void seq_bprintf(struct seq_file *m, const char *f, const u32 *binary);
159#endif
160
161#define DEFINE_SEQ_ATTRIBUTE(__name) \
162static int __name ## _open(struct inode *inode, struct file *file) \
163{ \
164 int ret = seq_open(file, &__name ## _sops); \
165 if (!ret && inode->i_private) { \
166 struct seq_file *seq_f = file->private_data; \
167 seq_f->private = inode->i_private; \
168 } \
169 return ret; \
170} \
171 \
172static const struct file_operations __name ## _fops = { \
173 .owner = THIS_MODULE, \
174 .open = __name ## _open, \
175 .read = seq_read, \
176 .llseek = seq_lseek, \
177 .release = seq_release, \
178}
179
180#define DEFINE_SHOW_ATTRIBUTE(__name) \
181static int __name ## _open(struct inode *inode, struct file *file) \
182{ \
183 return single_open(file, __name ## _show, inode->i_private); \
184} \
185 \
186static const struct file_operations __name ## _fops = { \
187 .owner = THIS_MODULE, \
188 .open = __name ## _open, \
189 .read = seq_read, \
190 .llseek = seq_lseek, \
191 .release = single_release, \
192}
193
194#define DEFINE_PROC_SHOW_ATTRIBUTE(__name) \
195static int __name ## _open(struct inode *inode, struct file *file) \
196{ \
197 return single_open(file, __name ## _show, inode->i_private); \
198} \
199 \
200static const struct proc_ops __name ## _proc_ops = { \
201 .proc_open = __name ## _open, \
202 .proc_read = seq_read, \
203 .proc_lseek = seq_lseek, \
204 .proc_release = single_release, \
205}
206
207static inline struct user_namespace *seq_user_ns(struct seq_file *seq)
208{
209#ifdef CONFIG_USER_NS
210 return seq->file->f_cred->user_ns;
211#else
212 extern struct user_namespace init_user_ns;
213 return &init_user_ns;
214#endif
215}
216
217/**
218 * seq_show_options - display mount options with appropriate escapes.
219 * @m: the seq_file handle
220 * @name: the mount option name
221 * @value: the mount option name's value, can be NULL
222 */
223static inline void seq_show_option(struct seq_file *m, const char *name,
224 const char *value)
225{
226 seq_putc(m, ',');
227 seq_escape(m, name, ",= \t\n\\");
228 if (value) {
229 seq_putc(m, '=');
230 seq_escape(m, value, ", \t\n\\");
231 }
232}
233
234/**
235 * seq_show_option_n - display mount options with appropriate escapes
236 * where @value must be a specific length.
237 * @m: the seq_file handle
238 * @name: the mount option name
239 * @value: the mount option name's value, cannot be NULL
240 * @length: the length of @value to display
241 *
242 * This is a macro since this uses "length" to define the size of the
243 * stack buffer.
244 */
245#define seq_show_option_n(m, name, value, length) { \
246 char val_buf[length + 1]; \
247 strncpy(val_buf, value, length); \
248 val_buf[length] = '\0'; \
249 seq_show_option(m, name, val_buf); \
250}
251
252#define SEQ_START_TOKEN ((void *)1)
253/*
254 * Helpers for iteration over list_head-s in seq_files
255 */
256
257extern struct list_head *seq_list_start(struct list_head *head,
258 loff_t pos);
259extern struct list_head *seq_list_start_head(struct list_head *head,
260 loff_t pos);
261extern struct list_head *seq_list_next(void *v, struct list_head *head,
262 loff_t *ppos);
263
264/*
265 * Helpers for iteration over hlist_head-s in seq_files
266 */
267
268extern struct hlist_node *seq_hlist_start(struct hlist_head *head,
269 loff_t pos);
270extern struct hlist_node *seq_hlist_start_head(struct hlist_head *head,
271 loff_t pos);
272extern struct hlist_node *seq_hlist_next(void *v, struct hlist_head *head,
273 loff_t *ppos);
274
275extern struct hlist_node *seq_hlist_start_rcu(struct hlist_head *head,
276 loff_t pos);
277extern struct hlist_node *seq_hlist_start_head_rcu(struct hlist_head *head,
278 loff_t pos);
279extern struct hlist_node *seq_hlist_next_rcu(void *v,
280 struct hlist_head *head,
281 loff_t *ppos);
282
283/* Helpers for iterating over per-cpu hlist_head-s in seq_files */
284extern struct hlist_node *seq_hlist_start_percpu(struct hlist_head __percpu *head, int *cpu, loff_t pos);
285
286extern struct hlist_node *seq_hlist_next_percpu(void *v, struct hlist_head __percpu *head, int *cpu, loff_t *pos);
287
288void seq_file_init(void);
289#endif
1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef _LINUX_SEQ_FILE_H
3#define _LINUX_SEQ_FILE_H
4
5#include <linux/types.h>
6#include <linux/string.h>
7#include <linux/string_helpers.h>
8#include <linux/bug.h>
9#include <linux/mutex.h>
10#include <linux/cpumask.h>
11#include <linux/nodemask.h>
12#include <linux/fs.h>
13#include <linux/cred.h>
14
15struct seq_operations;
16
17struct seq_file {
18 char *buf;
19 size_t size;
20 size_t from;
21 size_t count;
22 size_t pad_until;
23 loff_t index;
24 loff_t read_pos;
25 struct mutex lock;
26 const struct seq_operations *op;
27 int poll_event;
28 const struct file *file;
29 void *private;
30};
31
32struct seq_operations {
33 void * (*start) (struct seq_file *m, loff_t *pos);
34 void (*stop) (struct seq_file *m, void *v);
35 void * (*next) (struct seq_file *m, void *v, loff_t *pos);
36 int (*show) (struct seq_file *m, void *v);
37};
38
39#define SEQ_SKIP 1
40
41/**
42 * seq_has_overflowed - check if the buffer has overflowed
43 * @m: the seq_file handle
44 *
45 * seq_files have a buffer which may overflow. When this happens a larger
46 * buffer is reallocated and all the data will be printed again.
47 * The overflow state is true when m->count == m->size.
48 *
49 * Returns true if the buffer received more than it can hold.
50 */
51static inline bool seq_has_overflowed(struct seq_file *m)
52{
53 return m->count == m->size;
54}
55
56/**
57 * seq_get_buf - get buffer to write arbitrary data to
58 * @m: the seq_file handle
59 * @bufp: the beginning of the buffer is stored here
60 *
61 * Return the number of bytes available in the buffer, or zero if
62 * there's no space.
63 */
64static inline size_t seq_get_buf(struct seq_file *m, char **bufp)
65{
66 BUG_ON(m->count > m->size);
67 if (m->count < m->size)
68 *bufp = m->buf + m->count;
69 else
70 *bufp = NULL;
71
72 return m->size - m->count;
73}
74
75/**
76 * seq_commit - commit data to the buffer
77 * @m: the seq_file handle
78 * @num: the number of bytes to commit
79 *
80 * Commit @num bytes of data written to a buffer previously acquired
81 * by seq_buf_get. To signal an error condition, or that the data
82 * didn't fit in the available space, pass a negative @num value.
83 */
84static inline void seq_commit(struct seq_file *m, int num)
85{
86 if (num < 0) {
87 m->count = m->size;
88 } else {
89 BUG_ON(m->count + num > m->size);
90 m->count += num;
91 }
92}
93
94/**
95 * seq_setwidth - set padding width
96 * @m: the seq_file handle
97 * @size: the max number of bytes to pad.
98 *
99 * Call seq_setwidth() for setting max width, then call seq_printf() etc. and
100 * finally call seq_pad() to pad the remaining bytes.
101 */
102static inline void seq_setwidth(struct seq_file *m, size_t size)
103{
104 m->pad_until = m->count + size;
105}
106void seq_pad(struct seq_file *m, char c);
107
108char *mangle_path(char *s, const char *p, const char *esc);
109int seq_open(struct file *, const struct seq_operations *);
110ssize_t seq_read(struct file *, char __user *, size_t, loff_t *);
111ssize_t seq_read_iter(struct kiocb *iocb, struct iov_iter *iter);
112loff_t seq_lseek(struct file *, loff_t, int);
113int seq_release(struct inode *, struct file *);
114int seq_write(struct seq_file *seq, const void *data, size_t len);
115
116__printf(2, 0)
117void seq_vprintf(struct seq_file *m, const char *fmt, va_list args);
118__printf(2, 3)
119void seq_printf(struct seq_file *m, const char *fmt, ...);
120void seq_putc(struct seq_file *m, char c);
121void seq_puts(struct seq_file *m, const char *s);
122void seq_put_decimal_ull_width(struct seq_file *m, const char *delimiter,
123 unsigned long long num, unsigned int width);
124void seq_put_decimal_ull(struct seq_file *m, const char *delimiter,
125 unsigned long long num);
126void seq_put_decimal_ll(struct seq_file *m, const char *delimiter, long long num);
127void seq_put_hex_ll(struct seq_file *m, const char *delimiter,
128 unsigned long long v, unsigned int width);
129
130void seq_escape_mem(struct seq_file *m, const char *src, size_t len,
131 unsigned int flags, const char *esc);
132
133static inline void seq_escape_str(struct seq_file *m, const char *src,
134 unsigned int flags, const char *esc)
135{
136 seq_escape_mem(m, src, strlen(src), flags, esc);
137}
138
139/**
140 * seq_escape - print string into buffer, escaping some characters
141 * @m: target buffer
142 * @s: NULL-terminated string
143 * @esc: set of characters that need escaping
144 *
145 * Puts string into buffer, replacing each occurrence of character from
146 * @esc with usual octal escape.
147 *
148 * Use seq_has_overflowed() to check for errors.
149 */
150static inline void seq_escape(struct seq_file *m, const char *s, const char *esc)
151{
152 seq_escape_str(m, s, ESCAPE_OCTAL, esc);
153}
154
155void seq_hex_dump(struct seq_file *m, const char *prefix_str, int prefix_type,
156 int rowsize, int groupsize, const void *buf, size_t len,
157 bool ascii);
158
159int seq_path(struct seq_file *, const struct path *, const char *);
160int seq_file_path(struct seq_file *, struct file *, const char *);
161int seq_dentry(struct seq_file *, struct dentry *, const char *);
162int seq_path_root(struct seq_file *m, const struct path *path,
163 const struct path *root, const char *esc);
164
165void *single_start(struct seq_file *, loff_t *);
166int single_open(struct file *, int (*)(struct seq_file *, void *), void *);
167int single_open_size(struct file *, int (*)(struct seq_file *, void *), void *, size_t);
168int single_release(struct inode *, struct file *);
169void *__seq_open_private(struct file *, const struct seq_operations *, int);
170int seq_open_private(struct file *, const struct seq_operations *, int);
171int seq_release_private(struct inode *, struct file *);
172
173#ifdef CONFIG_BINARY_PRINTF
174void seq_bprintf(struct seq_file *m, const char *f, const u32 *binary);
175#endif
176
177#define DEFINE_SEQ_ATTRIBUTE(__name) \
178static int __name ## _open(struct inode *inode, struct file *file) \
179{ \
180 int ret = seq_open(file, &__name ## _sops); \
181 if (!ret && inode->i_private) { \
182 struct seq_file *seq_f = file->private_data; \
183 seq_f->private = inode->i_private; \
184 } \
185 return ret; \
186} \
187 \
188static const struct file_operations __name ## _fops = { \
189 .owner = THIS_MODULE, \
190 .open = __name ## _open, \
191 .read = seq_read, \
192 .llseek = seq_lseek, \
193 .release = seq_release, \
194}
195
196#define DEFINE_SHOW_ATTRIBUTE(__name) \
197static int __name ## _open(struct inode *inode, struct file *file) \
198{ \
199 return single_open(file, __name ## _show, inode->i_private); \
200} \
201 \
202static const struct file_operations __name ## _fops = { \
203 .owner = THIS_MODULE, \
204 .open = __name ## _open, \
205 .read = seq_read, \
206 .llseek = seq_lseek, \
207 .release = single_release, \
208}
209
210#define DEFINE_SHOW_STORE_ATTRIBUTE(__name) \
211static int __name ## _open(struct inode *inode, struct file *file) \
212{ \
213 return single_open(file, __name ## _show, inode->i_private); \
214} \
215 \
216static const struct file_operations __name ## _fops = { \
217 .owner = THIS_MODULE, \
218 .open = __name ## _open, \
219 .read = seq_read, \
220 .write = __name ## _write, \
221 .llseek = seq_lseek, \
222 .release = single_release, \
223}
224
225#define DEFINE_PROC_SHOW_ATTRIBUTE(__name) \
226static int __name ## _open(struct inode *inode, struct file *file) \
227{ \
228 return single_open(file, __name ## _show, pde_data(inode)); \
229} \
230 \
231static const struct proc_ops __name ## _proc_ops = { \
232 .proc_open = __name ## _open, \
233 .proc_read = seq_read, \
234 .proc_lseek = seq_lseek, \
235 .proc_release = single_release, \
236}
237
238static inline struct user_namespace *seq_user_ns(struct seq_file *seq)
239{
240#ifdef CONFIG_USER_NS
241 return seq->file->f_cred->user_ns;
242#else
243 extern struct user_namespace init_user_ns;
244 return &init_user_ns;
245#endif
246}
247
248/**
249 * seq_show_options - display mount options with appropriate escapes.
250 * @m: the seq_file handle
251 * @name: the mount option name
252 * @value: the mount option name's value, can be NULL
253 */
254static inline void seq_show_option(struct seq_file *m, const char *name,
255 const char *value)
256{
257 seq_putc(m, ',');
258 seq_escape(m, name, ",= \t\n\\");
259 if (value) {
260 seq_putc(m, '=');
261 seq_escape(m, value, ", \t\n\\");
262 }
263}
264
265/**
266 * seq_show_option_n - display mount options with appropriate escapes
267 * where @value must be a specific length (i.e.
268 * not NUL-terminated).
269 * @m: the seq_file handle
270 * @name: the mount option name
271 * @value: the mount option name's value, cannot be NULL
272 * @length: the exact length of @value to display, must be constant expression
273 *
274 * This is a macro since this uses "length" to define the size of the
275 * stack buffer.
276 */
277#define seq_show_option_n(m, name, value, length) { \
278 char val_buf[length + 1]; \
279 memcpy(val_buf, value, length); \
280 val_buf[length] = '\0'; \
281 seq_show_option(m, name, val_buf); \
282}
283
284#define SEQ_START_TOKEN ((void *)1)
285/*
286 * Helpers for iteration over list_head-s in seq_files
287 */
288
289extern struct list_head *seq_list_start(struct list_head *head,
290 loff_t pos);
291extern struct list_head *seq_list_start_head(struct list_head *head,
292 loff_t pos);
293extern struct list_head *seq_list_next(void *v, struct list_head *head,
294 loff_t *ppos);
295
296extern struct list_head *seq_list_start_rcu(struct list_head *head, loff_t pos);
297extern struct list_head *seq_list_start_head_rcu(struct list_head *head, loff_t pos);
298extern struct list_head *seq_list_next_rcu(void *v, struct list_head *head, loff_t *ppos);
299
300/*
301 * Helpers for iteration over hlist_head-s in seq_files
302 */
303
304extern struct hlist_node *seq_hlist_start(struct hlist_head *head,
305 loff_t pos);
306extern struct hlist_node *seq_hlist_start_head(struct hlist_head *head,
307 loff_t pos);
308extern struct hlist_node *seq_hlist_next(void *v, struct hlist_head *head,
309 loff_t *ppos);
310
311extern struct hlist_node *seq_hlist_start_rcu(struct hlist_head *head,
312 loff_t pos);
313extern struct hlist_node *seq_hlist_start_head_rcu(struct hlist_head *head,
314 loff_t pos);
315extern struct hlist_node *seq_hlist_next_rcu(void *v,
316 struct hlist_head *head,
317 loff_t *ppos);
318
319/* Helpers for iterating over per-cpu hlist_head-s in seq_files */
320extern struct hlist_node *seq_hlist_start_percpu(struct hlist_head __percpu *head, int *cpu, loff_t pos);
321
322extern struct hlist_node *seq_hlist_next_percpu(void *v, struct hlist_head __percpu *head, int *cpu, loff_t *pos);
323
324void seq_file_init(void);
325#endif