xref: /linux-6.15/include/linux/proc_fs.h (revision a078ccff)
1 #ifndef _LINUX_PROC_FS_H
2 #define _LINUX_PROC_FS_H
3 
4 #include <linux/slab.h>
5 #include <linux/fs.h>
6 #include <linux/spinlock.h>
7 #include <linux/magic.h>
8 #include <linux/atomic.h>
9 
10 struct net;
11 struct completion;
12 struct mm_struct;
13 
14 /*
15  * The proc filesystem constants/structures
16  */
17 
18 /*
19  * Offset of the first process in the /proc root directory..
20  */
21 #define FIRST_PROCESS_ENTRY 256
22 
23 /* Worst case buffer size needed for holding an integer. */
24 #define PROC_NUMBUF 13
25 
26 /*
27  * We always define these enumerators
28  */
29 
30 enum {
31 	PROC_ROOT_INO		= 1,
32 	PROC_IPC_INIT_INO	= 0xEFFFFFFFU,
33 	PROC_UTS_INIT_INO	= 0xEFFFFFFEU,
34 	PROC_USER_INIT_INO	= 0xEFFFFFFDU,
35 	PROC_PID_INIT_INO	= 0xEFFFFFFCU,
36 };
37 
38 /*
39  * This is not completely implemented yet. The idea is to
40  * create an in-memory tree (like the actual /proc filesystem
41  * tree) of these proc_dir_entries, so that we can dynamically
42  * add new files to /proc.
43  *
44  * The "next" pointer creates a linked list of one /proc directory,
45  * while parent/subdir create the directory structure (every
46  * /proc file has a parent, but "subdir" is NULL for all
47  * non-directory entries).
48  */
49 
50 typedef	int (read_proc_t)(char *page, char **start, off_t off,
51 			  int count, int *eof, void *data);
52 typedef	int (write_proc_t)(struct file *file, const char __user *buffer,
53 			   unsigned long count, void *data);
54 
55 struct proc_dir_entry {
56 	unsigned int low_ino;
57 	umode_t mode;
58 	nlink_t nlink;
59 	kuid_t uid;
60 	kgid_t gid;
61 	loff_t size;
62 	const struct inode_operations *proc_iops;
63 	/*
64 	 * NULL ->proc_fops means "PDE is going away RSN" or
65 	 * "PDE is just created". In either case, e.g. ->read_proc won't be
66 	 * called because it's too late or too early, respectively.
67 	 *
68 	 * If you're allocating ->proc_fops dynamically, save a pointer
69 	 * somewhere.
70 	 */
71 	const struct file_operations *proc_fops;
72 	struct proc_dir_entry *next, *parent, *subdir;
73 	void *data;
74 	read_proc_t *read_proc;
75 	write_proc_t *write_proc;
76 	atomic_t count;		/* use count */
77 	int pde_users;	/* number of callers into module in progress */
78 	struct completion *pde_unload_completion;
79 	struct list_head pde_openers;	/* who did ->open, but not ->release */
80 	spinlock_t pde_unload_lock; /* proc_fops checks and pde_users bumps */
81 	u8 namelen;
82 	char name[];
83 };
84 
85 enum kcore_type {
86 	KCORE_TEXT,
87 	KCORE_VMALLOC,
88 	KCORE_RAM,
89 	KCORE_VMEMMAP,
90 	KCORE_OTHER,
91 };
92 
93 struct kcore_list {
94 	struct list_head list;
95 	unsigned long addr;
96 	size_t size;
97 	int type;
98 };
99 
100 struct vmcore {
101 	struct list_head list;
102 	unsigned long long paddr;
103 	unsigned long long size;
104 	loff_t offset;
105 };
106 
107 #ifdef CONFIG_PROC_FS
108 
109 extern void proc_root_init(void);
110 
111 void proc_flush_task(struct task_struct *task);
112 
113 extern struct proc_dir_entry *create_proc_entry(const char *name, umode_t mode,
114 						struct proc_dir_entry *parent);
115 struct proc_dir_entry *proc_create_data(const char *name, umode_t mode,
116 				struct proc_dir_entry *parent,
117 				const struct file_operations *proc_fops,
118 				void *data);
119 extern void remove_proc_entry(const char *name, struct proc_dir_entry *parent);
120 extern int remove_proc_subtree(const char *name, struct proc_dir_entry *parent);
121 
122 struct pid_namespace;
123 
124 extern int pid_ns_prepare_proc(struct pid_namespace *ns);
125 extern void pid_ns_release_proc(struct pid_namespace *ns);
126 
127 /*
128  * proc_tty.c
129  */
130 struct tty_driver;
131 #ifdef CONFIG_TTY
132 extern void proc_tty_init(void);
133 #else
134 static inline void proc_tty_init(void)
135 { }
136 #endif
137 extern void proc_tty_register_driver(struct tty_driver *driver);
138 extern void proc_tty_unregister_driver(struct tty_driver *driver);
139 
140 /*
141  * proc_devtree.c
142  */
143 #ifdef CONFIG_PROC_DEVICETREE
144 struct device_node;
145 struct property;
146 extern void proc_device_tree_init(void);
147 extern void proc_device_tree_add_node(struct device_node *, struct proc_dir_entry *);
148 extern void proc_device_tree_add_prop(struct proc_dir_entry *pde, struct property *prop);
149 extern void proc_device_tree_remove_prop(struct proc_dir_entry *pde,
150 					 struct property *prop);
151 extern void proc_device_tree_update_prop(struct proc_dir_entry *pde,
152 					 struct property *newprop,
153 					 struct property *oldprop);
154 #endif /* CONFIG_PROC_DEVICETREE */
155 
156 extern struct proc_dir_entry *proc_symlink(const char *,
157 		struct proc_dir_entry *, const char *);
158 extern struct proc_dir_entry *proc_mkdir(const char *,struct proc_dir_entry *);
159 extern struct proc_dir_entry *proc_mkdir_mode(const char *name, umode_t mode,
160 			struct proc_dir_entry *parent);
161 
162 static inline struct proc_dir_entry *proc_create(const char *name, umode_t mode,
163 	struct proc_dir_entry *parent, const struct file_operations *proc_fops)
164 {
165 	return proc_create_data(name, mode, parent, proc_fops, NULL);
166 }
167 
168 static inline struct proc_dir_entry *create_proc_read_entry(const char *name,
169 	umode_t mode, struct proc_dir_entry *base,
170 	read_proc_t *read_proc, void * data)
171 {
172 	struct proc_dir_entry *res=create_proc_entry(name,mode,base);
173 	if (res) {
174 		res->read_proc=read_proc;
175 		res->data=data;
176 	}
177 	return res;
178 }
179 
180 extern struct proc_dir_entry *proc_net_mkdir(struct net *net, const char *name,
181 	struct proc_dir_entry *parent);
182 
183 extern struct file *proc_ns_fget(int fd);
184 extern bool proc_ns_inode(struct inode *inode);
185 
186 extern int proc_alloc_inum(unsigned int *pino);
187 extern void proc_free_inum(unsigned int inum);
188 #else
189 
190 static inline void proc_flush_task(struct task_struct *task)
191 {
192 }
193 
194 static inline struct proc_dir_entry *create_proc_entry(const char *name,
195 	umode_t mode, struct proc_dir_entry *parent) { return NULL; }
196 
197 #define proc_create(name, mode, parent, fops)  ({ (void)(mode), NULL; })
198 
199 static inline struct proc_dir_entry *proc_create_data(const char *name,
200 	umode_t mode, struct proc_dir_entry *parent,
201 	const struct file_operations *proc_fops, void *data)
202 {
203 	return NULL;
204 }
205 #define remove_proc_entry(name, parent) do {} while (0)
206 #define remove_proc_subtree(name, parent) do {} while (0)
207 
208 static inline struct proc_dir_entry *proc_symlink(const char *name,
209 		struct proc_dir_entry *parent,const char *dest) {return NULL;}
210 static inline struct proc_dir_entry *proc_mkdir(const char *name,
211 	struct proc_dir_entry *parent) {return NULL;}
212 static inline struct proc_dir_entry *proc_mkdir_mode(const char *name,
213 	umode_t mode, struct proc_dir_entry *parent) { return NULL; }
214 
215 static inline struct proc_dir_entry *create_proc_read_entry(const char *name,
216 	umode_t mode, struct proc_dir_entry *base,
217 	read_proc_t *read_proc, void * data) { return NULL; }
218 
219 struct tty_driver;
220 static inline void proc_tty_register_driver(struct tty_driver *driver) {};
221 static inline void proc_tty_unregister_driver(struct tty_driver *driver) {};
222 
223 static inline int pid_ns_prepare_proc(struct pid_namespace *ns)
224 {
225 	return 0;
226 }
227 
228 static inline void pid_ns_release_proc(struct pid_namespace *ns)
229 {
230 }
231 
232 static inline struct file *proc_ns_fget(int fd)
233 {
234 	return ERR_PTR(-EINVAL);
235 }
236 
237 static inline bool proc_ns_inode(struct inode *inode)
238 {
239 	return false;
240 }
241 
242 static inline int proc_alloc_inum(unsigned int *inum)
243 {
244 	*inum = 1;
245 	return 0;
246 }
247 static inline void proc_free_inum(unsigned int inum)
248 {
249 }
250 #endif /* CONFIG_PROC_FS */
251 
252 #if !defined(CONFIG_PROC_KCORE)
253 static inline void
254 kclist_add(struct kcore_list *new, void *addr, size_t size, int type)
255 {
256 }
257 #else
258 extern void kclist_add(struct kcore_list *, void *, size_t, int type);
259 #endif
260 
261 struct nsproxy;
262 struct proc_ns_operations {
263 	const char *name;
264 	int type;
265 	void *(*get)(struct task_struct *task);
266 	void (*put)(void *ns);
267 	int (*install)(struct nsproxy *nsproxy, void *ns);
268 	unsigned int (*inum)(void *ns);
269 };
270 extern const struct proc_ns_operations netns_operations;
271 extern const struct proc_ns_operations utsns_operations;
272 extern const struct proc_ns_operations ipcns_operations;
273 extern const struct proc_ns_operations pidns_operations;
274 extern const struct proc_ns_operations userns_operations;
275 extern const struct proc_ns_operations mntns_operations;
276 
277 union proc_op {
278 	int (*proc_get_link)(struct dentry *, struct path *);
279 	int (*proc_read)(struct task_struct *task, char *page);
280 	int (*proc_show)(struct seq_file *m,
281 		struct pid_namespace *ns, struct pid *pid,
282 		struct task_struct *task);
283 };
284 
285 struct ctl_table_header;
286 struct ctl_table;
287 
288 struct proc_inode {
289 	struct pid *pid;
290 	int fd;
291 	union proc_op op;
292 	struct proc_dir_entry *pde;
293 	struct ctl_table_header *sysctl;
294 	struct ctl_table *sysctl_entry;
295 	void *ns;
296 	const struct proc_ns_operations *ns_ops;
297 	struct inode vfs_inode;
298 };
299 
300 static inline struct proc_inode *PROC_I(const struct inode *inode)
301 {
302 	return container_of(inode, struct proc_inode, vfs_inode);
303 }
304 
305 static inline struct proc_dir_entry *PDE(const struct inode *inode)
306 {
307 	return PROC_I(inode)->pde;
308 }
309 
310 static inline struct net *PDE_NET(struct proc_dir_entry *pde)
311 {
312 	return pde->parent->data;
313 }
314 
315 #include <linux/signal.h>
316 
317 void render_sigset_t(struct seq_file *m, const char *header, sigset_t *set);
318 #endif /* _LINUX_PROC_FS_H */
319