1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _LINUX_SEQ_FILE_H
3 #define _LINUX_SEQ_FILE_H
5 #include <linux/types.h>
6 #include <linux/string.h>
8 #include <linux/mutex.h>
9 #include <linux/cpumask.h>
10 #include <linux/nodemask.h>
12 #include <linux/cred.h>
14 struct seq_operations;
25 const struct seq_operations *op;
27 const struct file *file;
31 struct 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);
41 * seq_has_overflowed - check if the buffer has overflowed
42 * @m: the seq_file handle
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.
48 * Returns true if the buffer received more than it can hold.
50 static inline bool seq_has_overflowed(struct seq_file *m)
52 return m->count == m->size;
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
60 * Return the number of bytes available in the buffer, or zero if
63 static inline size_t seq_get_buf(struct seq_file *m, char **bufp)
65 BUG_ON(m->count > m->size);
66 if (m->count < m->size)
67 *bufp = m->buf + m->count;
71 return m->size - m->count;
75 * seq_commit - commit data to the buffer
76 * @m: the seq_file handle
77 * @num: the number of bytes to commit
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.
83 static inline void seq_commit(struct seq_file *m, int num)
88 BUG_ON(m->count + num > m->size);
94 * seq_setwidth - set padding width
95 * @m: the seq_file handle
96 * @size: the max number of bytes to pad.
98 * Call seq_setwidth() for setting max width, then call seq_printf() etc. and
99 * finally call seq_pad() to pad the remaining bytes.
101 static inline void seq_setwidth(struct seq_file *m, size_t size)
103 m->pad_until = m->count + size;
105 void seq_pad(struct seq_file *m, char c);
107 char *mangle_path(char *s, const char *p, const char *esc);
108 int seq_open(struct file *, const struct seq_operations *);
109 ssize_t seq_read(struct file *, char __user *, size_t, loff_t *);
110 loff_t seq_lseek(struct file *, loff_t, int);
111 int seq_release(struct inode *, struct file *);
112 int seq_write(struct seq_file *seq, const void *data, size_t len);
115 void seq_vprintf(struct seq_file *m, const char *fmt, va_list args);
117 void seq_printf(struct seq_file *m, const char *fmt, ...);
118 void seq_putc(struct seq_file *m, char c);
119 void seq_puts(struct seq_file *m, const char *s);
120 void seq_put_decimal_ull_width(struct seq_file *m, const char *delimiter,
121 unsigned long long num, unsigned int width);
122 void seq_put_decimal_ull(struct seq_file *m, const char *delimiter,
123 unsigned long long num);
124 void seq_put_decimal_ll(struct seq_file *m, const char *delimiter, long long num);
125 void seq_put_hex_ll(struct seq_file *m, const char *delimiter,
126 unsigned long long v, unsigned int width);
128 void seq_escape(struct seq_file *m, const char *s, const char *esc);
129 void seq_escape_mem_ascii(struct seq_file *m, const char *src, size_t isz);
131 void seq_hex_dump(struct seq_file *m, const char *prefix_str, int prefix_type,
132 int rowsize, int groupsize, const void *buf, size_t len,
135 int seq_path(struct seq_file *, const struct path *, const char *);
136 int seq_file_path(struct seq_file *, struct file *, const char *);
137 int seq_dentry(struct seq_file *, struct dentry *, const char *);
138 int seq_path_root(struct seq_file *m, const struct path *path,
139 const struct path *root, const char *esc);
141 int single_open(struct file *, int (*)(struct seq_file *, void *), void *);
142 int single_open_size(struct file *, int (*)(struct seq_file *, void *), void *, size_t);
143 int single_release(struct inode *, struct file *);
144 void *__seq_open_private(struct file *, const struct seq_operations *, int);
145 int seq_open_private(struct file *, const struct seq_operations *, int);
146 int seq_release_private(struct inode *, struct file *);
148 #define DEFINE_SHOW_ATTRIBUTE(__name) \
149 static int __name ## _open(struct inode *inode, struct file *file) \
151 return single_open(file, __name ## _show, inode->i_private); \
154 static const struct file_operations __name ## _fops = { \
155 .owner = THIS_MODULE, \
156 .open = __name ## _open, \
158 .llseek = seq_lseek, \
159 .release = single_release, \
162 #define DEFINE_PROC_SHOW_ATTRIBUTE(__name) \
163 static int __name ## _open(struct inode *inode, struct file *file) \
165 return single_open(file, __name ## _show, inode->i_private); \
168 static const struct proc_ops __name ## _proc_ops = { \
169 .proc_open = __name ## _open, \
170 .proc_read = seq_read, \
171 .proc_lseek = seq_lseek, \
172 .proc_release = single_release, \
175 static inline struct user_namespace *seq_user_ns(struct seq_file *seq)
177 #ifdef CONFIG_USER_NS
178 return seq->file->f_cred->user_ns;
180 extern struct user_namespace init_user_ns;
181 return &init_user_ns;
186 * seq_show_options - display mount options with appropriate escapes.
187 * @m: the seq_file handle
188 * @name: the mount option name
189 * @value: the mount option name's value, can be NULL
191 static inline void seq_show_option(struct seq_file *m, const char *name,
195 seq_escape(m, name, ",= \t\n\\");
198 seq_escape(m, value, ", \t\n\\");
203 * seq_show_option_n - display mount options with appropriate escapes
204 * where @value must be a specific length.
205 * @m: the seq_file handle
206 * @name: the mount option name
207 * @value: the mount option name's value, cannot be NULL
208 * @length: the length of @value to display
210 * This is a macro since this uses "length" to define the size of the
213 #define seq_show_option_n(m, name, value, length) { \
214 char val_buf[length + 1]; \
215 strncpy(val_buf, value, length); \
216 val_buf[length] = '\0'; \
217 seq_show_option(m, name, val_buf); \
220 #define SEQ_START_TOKEN ((void *)1)
222 * Helpers for iteration over list_head-s in seq_files
225 extern struct list_head *seq_list_start(struct list_head *head,
227 extern struct list_head *seq_list_start_head(struct list_head *head,
229 extern struct list_head *seq_list_next(void *v, struct list_head *head,
233 * Helpers for iteration over hlist_head-s in seq_files
236 extern struct hlist_node *seq_hlist_start(struct hlist_head *head,
238 extern struct hlist_node *seq_hlist_start_head(struct hlist_head *head,
240 extern struct hlist_node *seq_hlist_next(void *v, struct hlist_head *head,
243 extern struct hlist_node *seq_hlist_start_rcu(struct hlist_head *head,
245 extern struct hlist_node *seq_hlist_start_head_rcu(struct hlist_head *head,
247 extern struct hlist_node *seq_hlist_next_rcu(void *v,
248 struct hlist_head *head,
251 /* Helpers for iterating over per-cpu hlist_head-s in seq_files */
252 extern struct hlist_node *seq_hlist_start_percpu(struct hlist_head __percpu *head, int *cpu, loff_t pos);
254 extern struct hlist_node *seq_hlist_next_percpu(void *v, struct hlist_head __percpu *head, int *cpu, loff_t *pos);
256 void seq_file_init(void);