xref: /linux-6.15/include/linux/proc_fs.h (revision ecba1060)
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 <asm/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 };
33 
34 /*
35  * This is not completely implemented yet. The idea is to
36  * create an in-memory tree (like the actual /proc filesystem
37  * tree) of these proc_dir_entries, so that we can dynamically
38  * add new files to /proc.
39  *
40  * The "next" pointer creates a linked list of one /proc directory,
41  * while parent/subdir create the directory structure (every
42  * /proc file has a parent, but "subdir" is NULL for all
43  * non-directory entries).
44  */
45 
46 typedef	int (read_proc_t)(char *page, char **start, off_t off,
47 			  int count, int *eof, void *data);
48 typedef	int (write_proc_t)(struct file *file, const char __user *buffer,
49 			   unsigned long count, void *data);
50 
51 struct proc_dir_entry {
52 	unsigned int low_ino;
53 	unsigned short namelen;
54 	const char *name;
55 	mode_t mode;
56 	nlink_t nlink;
57 	uid_t uid;
58 	gid_t gid;
59 	loff_t size;
60 	const struct inode_operations *proc_iops;
61 	/*
62 	 * NULL ->proc_fops means "PDE is going away RSN" or
63 	 * "PDE is just created". In either case, e.g. ->read_proc won't be
64 	 * called because it's too late or too early, respectively.
65 	 *
66 	 * If you're allocating ->proc_fops dynamically, save a pointer
67 	 * somewhere.
68 	 */
69 	const struct file_operations *proc_fops;
70 	struct proc_dir_entry *next, *parent, *subdir;
71 	void *data;
72 	read_proc_t *read_proc;
73 	write_proc_t *write_proc;
74 	atomic_t count;		/* use count */
75 	int pde_users;	/* number of callers into module in progress */
76 	spinlock_t pde_unload_lock; /* proc_fops checks and pde_users bumps */
77 	struct completion *pde_unload_completion;
78 	struct list_head pde_openers;	/* who did ->open, but not ->release */
79 };
80 
81 struct kcore_list {
82 	struct kcore_list *next;
83 	unsigned long addr;
84 	size_t size;
85 };
86 
87 struct vmcore {
88 	struct list_head list;
89 	unsigned long long paddr;
90 	unsigned long long size;
91 	loff_t offset;
92 };
93 
94 #ifdef CONFIG_PROC_FS
95 
96 extern void proc_root_init(void);
97 
98 void proc_flush_task(struct task_struct *task);
99 
100 extern struct proc_dir_entry *create_proc_entry(const char *name, mode_t mode,
101 						struct proc_dir_entry *parent);
102 struct proc_dir_entry *proc_create_data(const char *name, mode_t mode,
103 				struct proc_dir_entry *parent,
104 				const struct file_operations *proc_fops,
105 				void *data);
106 extern void remove_proc_entry(const char *name, struct proc_dir_entry *parent);
107 
108 struct pid_namespace;
109 
110 extern int pid_ns_prepare_proc(struct pid_namespace *ns);
111 extern void pid_ns_release_proc(struct pid_namespace *ns);
112 
113 /*
114  * proc_tty.c
115  */
116 struct tty_driver;
117 extern void proc_tty_init(void);
118 extern void proc_tty_register_driver(struct tty_driver *driver);
119 extern void proc_tty_unregister_driver(struct tty_driver *driver);
120 
121 /*
122  * proc_devtree.c
123  */
124 #ifdef CONFIG_PROC_DEVICETREE
125 struct device_node;
126 struct property;
127 extern void proc_device_tree_init(void);
128 extern void proc_device_tree_add_node(struct device_node *, struct proc_dir_entry *);
129 extern void proc_device_tree_add_prop(struct proc_dir_entry *pde, struct property *prop);
130 extern void proc_device_tree_remove_prop(struct proc_dir_entry *pde,
131 					 struct property *prop);
132 extern void proc_device_tree_update_prop(struct proc_dir_entry *pde,
133 					 struct property *newprop,
134 					 struct property *oldprop);
135 #endif /* CONFIG_PROC_DEVICETREE */
136 
137 extern struct proc_dir_entry *proc_symlink(const char *,
138 		struct proc_dir_entry *, const char *);
139 extern struct proc_dir_entry *proc_mkdir(const char *,struct proc_dir_entry *);
140 extern struct proc_dir_entry *proc_mkdir_mode(const char *name, mode_t mode,
141 			struct proc_dir_entry *parent);
142 
143 static inline struct proc_dir_entry *proc_create(const char *name, mode_t mode,
144 	struct proc_dir_entry *parent, const struct file_operations *proc_fops)
145 {
146 	return proc_create_data(name, mode, parent, proc_fops, NULL);
147 }
148 
149 static inline struct proc_dir_entry *create_proc_read_entry(const char *name,
150 	mode_t mode, struct proc_dir_entry *base,
151 	read_proc_t *read_proc, void * data)
152 {
153 	struct proc_dir_entry *res=create_proc_entry(name,mode,base);
154 	if (res) {
155 		res->read_proc=read_proc;
156 		res->data=data;
157 	}
158 	return res;
159 }
160 
161 extern struct proc_dir_entry *proc_net_fops_create(struct net *net,
162 	const char *name, mode_t mode, const struct file_operations *fops);
163 extern void proc_net_remove(struct net *net, const char *name);
164 extern struct proc_dir_entry *proc_net_mkdir(struct net *net, const char *name,
165 	struct proc_dir_entry *parent);
166 
167 /* While the {get|set|dup}_mm_exe_file functions are for mm_structs, they are
168  * only needed to implement /proc/<pid>|self/exe so we define them here. */
169 extern void set_mm_exe_file(struct mm_struct *mm, struct file *new_exe_file);
170 extern struct file *get_mm_exe_file(struct mm_struct *mm);
171 extern void dup_mm_exe_file(struct mm_struct *oldmm, struct mm_struct *newmm);
172 
173 #else
174 
175 #define proc_net_fops_create(net, name, mode, fops)  ({ (void)(mode), NULL; })
176 static inline void proc_net_remove(struct net *net, const char *name) {}
177 
178 static inline void proc_flush_task(struct task_struct *task)
179 {
180 }
181 
182 static inline struct proc_dir_entry *create_proc_entry(const char *name,
183 	mode_t mode, struct proc_dir_entry *parent) { return NULL; }
184 static inline struct proc_dir_entry *proc_create(const char *name,
185 	mode_t mode, struct proc_dir_entry *parent,
186 	const struct file_operations *proc_fops)
187 {
188 	return NULL;
189 }
190 static inline struct proc_dir_entry *proc_create_data(const char *name,
191 	mode_t mode, struct proc_dir_entry *parent,
192 	const struct file_operations *proc_fops, void *data)
193 {
194 	return NULL;
195 }
196 #define remove_proc_entry(name, parent) do {} while (0)
197 
198 static inline struct proc_dir_entry *proc_symlink(const char *name,
199 		struct proc_dir_entry *parent,const char *dest) {return NULL;}
200 static inline struct proc_dir_entry *proc_mkdir(const char *name,
201 	struct proc_dir_entry *parent) {return NULL;}
202 
203 static inline struct proc_dir_entry *create_proc_read_entry(const char *name,
204 	mode_t mode, struct proc_dir_entry *base,
205 	read_proc_t *read_proc, void * data) { return NULL; }
206 
207 struct tty_driver;
208 static inline void proc_tty_register_driver(struct tty_driver *driver) {};
209 static inline void proc_tty_unregister_driver(struct tty_driver *driver) {};
210 
211 static inline int pid_ns_prepare_proc(struct pid_namespace *ns)
212 {
213 	return 0;
214 }
215 
216 static inline void pid_ns_release_proc(struct pid_namespace *ns)
217 {
218 }
219 
220 static inline void set_mm_exe_file(struct mm_struct *mm,
221 				   struct file *new_exe_file)
222 {}
223 
224 static inline struct file *get_mm_exe_file(struct mm_struct *mm)
225 {
226 	return NULL;
227 }
228 
229 static inline void dup_mm_exe_file(struct mm_struct *oldmm,
230 	       			   struct mm_struct *newmm)
231 {}
232 
233 #endif /* CONFIG_PROC_FS */
234 
235 #if !defined(CONFIG_PROC_KCORE)
236 static inline void kclist_add(struct kcore_list *new, void *addr, size_t size)
237 {
238 }
239 #else
240 extern void kclist_add(struct kcore_list *, void *, size_t);
241 #endif
242 
243 union proc_op {
244 	int (*proc_get_link)(struct inode *, struct path *);
245 	int (*proc_read)(struct task_struct *task, char *page);
246 	int (*proc_show)(struct seq_file *m,
247 		struct pid_namespace *ns, struct pid *pid,
248 		struct task_struct *task);
249 };
250 
251 struct ctl_table_header;
252 struct ctl_table;
253 
254 struct proc_inode {
255 	struct pid *pid;
256 	int fd;
257 	union proc_op op;
258 	struct proc_dir_entry *pde;
259 	struct ctl_table_header *sysctl;
260 	struct ctl_table *sysctl_entry;
261 	struct inode vfs_inode;
262 };
263 
264 static inline struct proc_inode *PROC_I(const struct inode *inode)
265 {
266 	return container_of(inode, struct proc_inode, vfs_inode);
267 }
268 
269 static inline struct proc_dir_entry *PDE(const struct inode *inode)
270 {
271 	return PROC_I(inode)->pde;
272 }
273 
274 static inline struct net *PDE_NET(struct proc_dir_entry *pde)
275 {
276 	return pde->parent->data;
277 }
278 
279 struct proc_maps_private {
280 	struct pid *pid;
281 	struct task_struct *task;
282 #ifdef CONFIG_MMU
283 	struct vm_area_struct *tail_vma;
284 #endif
285 };
286 
287 #endif /* _LINUX_PROC_FS_H */
288