xref: /linux-6.15/include/linux/proc_fs.h (revision 930cc144)
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  * "owner" is used to protect module
46  * from unloading while proc_dir_entry is in use
47  */
48 
49 typedef	int (read_proc_t)(char *page, char **start, off_t off,
50 			  int count, int *eof, void *data);
51 typedef	int (write_proc_t)(struct file *file, const char __user *buffer,
52 			   unsigned long count, void *data);
53 
54 struct proc_dir_entry {
55 	unsigned int low_ino;
56 	unsigned short namelen;
57 	const char *name;
58 	mode_t mode;
59 	nlink_t nlink;
60 	uid_t uid;
61 	gid_t gid;
62 	loff_t size;
63 	const struct inode_operations *proc_iops;
64 	/*
65 	 * NULL ->proc_fops means "PDE is going away RSN" or
66 	 * "PDE is just created". In either case, e.g. ->read_proc won't be
67 	 * called because it's too late or too early, respectively.
68 	 *
69 	 * If you're allocating ->proc_fops dynamically, save a pointer
70 	 * somewhere.
71 	 */
72 	const struct file_operations *proc_fops;
73 	struct module *owner;
74 	struct proc_dir_entry *next, *parent, *subdir;
75 	void *data;
76 	read_proc_t *read_proc;
77 	write_proc_t *write_proc;
78 	atomic_t count;		/* use count */
79 	int pde_users;	/* number of callers into module in progress */
80 	spinlock_t pde_unload_lock; /* proc_fops checks and pde_users bumps */
81 	struct completion *pde_unload_completion;
82 	struct list_head pde_openers;	/* who did ->open, but not ->release */
83 };
84 
85 struct kcore_list {
86 	struct kcore_list *next;
87 	unsigned long addr;
88 	size_t size;
89 };
90 
91 struct vmcore {
92 	struct list_head list;
93 	unsigned long long paddr;
94 	unsigned long long size;
95 	loff_t offset;
96 };
97 
98 #ifdef CONFIG_PROC_FS
99 
100 extern struct proc_dir_entry *proc_root_kcore;
101 
102 extern spinlock_t proc_subdir_lock;
103 
104 extern void proc_root_init(void);
105 extern void proc_misc_init(void);
106 
107 void proc_flush_task(struct task_struct *task);
108 struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *);
109 int proc_pid_readdir(struct file * filp, void * dirent, filldir_t filldir);
110 unsigned long task_vsize(struct mm_struct *);
111 int task_statm(struct mm_struct *, int *, int *, int *, int *);
112 void task_mem(struct seq_file *, struct mm_struct *);
113 void clear_refs_smap(struct mm_struct *mm);
114 
115 struct proc_dir_entry *de_get(struct proc_dir_entry *de);
116 void de_put(struct proc_dir_entry *de);
117 
118 extern struct proc_dir_entry *create_proc_entry(const char *name, mode_t mode,
119 						struct proc_dir_entry *parent);
120 struct proc_dir_entry *proc_create_data(const char *name, mode_t mode,
121 				struct proc_dir_entry *parent,
122 				const struct file_operations *proc_fops,
123 				void *data);
124 extern void remove_proc_entry(const char *name, struct proc_dir_entry *parent);
125 
126 extern struct vfsmount *proc_mnt;
127 struct pid_namespace;
128 extern int proc_fill_super(struct super_block *);
129 extern struct inode *proc_get_inode(struct super_block *, unsigned int, struct proc_dir_entry *);
130 
131 /*
132  * These are generic /proc routines that use the internal
133  * "struct proc_dir_entry" tree to traverse the filesystem.
134  *
135  * The /proc root directory has extended versions to take care
136  * of the /proc/<pid> subdirectories.
137  */
138 extern int proc_readdir(struct file *, void *, filldir_t);
139 extern struct dentry *proc_lookup(struct inode *, struct dentry *, struct nameidata *);
140 
141 extern const struct file_operations proc_kcore_operations;
142 
143 extern int pid_ns_prepare_proc(struct pid_namespace *ns);
144 extern void pid_ns_release_proc(struct pid_namespace *ns);
145 
146 /*
147  * proc_tty.c
148  */
149 struct tty_driver;
150 extern void proc_tty_init(void);
151 extern void proc_tty_register_driver(struct tty_driver *driver);
152 extern void proc_tty_unregister_driver(struct tty_driver *driver);
153 
154 /*
155  * proc_devtree.c
156  */
157 #ifdef CONFIG_PROC_DEVICETREE
158 struct device_node;
159 struct property;
160 extern void proc_device_tree_init(void);
161 extern void proc_device_tree_add_node(struct device_node *, struct proc_dir_entry *);
162 extern void proc_device_tree_add_prop(struct proc_dir_entry *pde, struct property *prop);
163 extern void proc_device_tree_remove_prop(struct proc_dir_entry *pde,
164 					 struct property *prop);
165 extern void proc_device_tree_update_prop(struct proc_dir_entry *pde,
166 					 struct property *newprop,
167 					 struct property *oldprop);
168 #endif /* CONFIG_PROC_DEVICETREE */
169 
170 extern struct proc_dir_entry *proc_symlink(const char *,
171 		struct proc_dir_entry *, const char *);
172 extern struct proc_dir_entry *proc_mkdir(const char *,struct proc_dir_entry *);
173 extern struct proc_dir_entry *proc_mkdir_mode(const char *name, mode_t mode,
174 			struct proc_dir_entry *parent);
175 
176 static inline struct proc_dir_entry *proc_create(const char *name, mode_t mode,
177 	struct proc_dir_entry *parent, const struct file_operations *proc_fops)
178 {
179 	return proc_create_data(name, mode, parent, proc_fops, NULL);
180 }
181 
182 static inline struct proc_dir_entry *create_proc_read_entry(const char *name,
183 	mode_t mode, struct proc_dir_entry *base,
184 	read_proc_t *read_proc, void * data)
185 {
186 	struct proc_dir_entry *res=create_proc_entry(name,mode,base);
187 	if (res) {
188 		res->read_proc=read_proc;
189 		res->data=data;
190 	}
191 	return res;
192 }
193 
194 extern struct proc_dir_entry *proc_net_fops_create(struct net *net,
195 	const char *name, mode_t mode, const struct file_operations *fops);
196 extern void proc_net_remove(struct net *net, const char *name);
197 extern struct proc_dir_entry *proc_net_mkdir(struct net *net, const char *name,
198 	struct proc_dir_entry *parent);
199 
200 /* While the {get|set|dup}_mm_exe_file functions are for mm_structs, they are
201  * only needed to implement /proc/<pid>|self/exe so we define them here. */
202 extern void set_mm_exe_file(struct mm_struct *mm, struct file *new_exe_file);
203 extern struct file *get_mm_exe_file(struct mm_struct *mm);
204 extern void dup_mm_exe_file(struct mm_struct *oldmm, struct mm_struct *newmm);
205 
206 #else
207 
208 #define proc_net_fops_create(net, name, mode, fops)  ({ (void)(mode), NULL; })
209 static inline void proc_net_remove(struct net *net, const char *name) {}
210 
211 static inline void proc_flush_task(struct task_struct *task)
212 {
213 }
214 
215 static inline struct proc_dir_entry *create_proc_entry(const char *name,
216 	mode_t mode, struct proc_dir_entry *parent) { return NULL; }
217 static inline struct proc_dir_entry *proc_create(const char *name,
218 	mode_t mode, struct proc_dir_entry *parent,
219 	const struct file_operations *proc_fops)
220 {
221 	return NULL;
222 }
223 static inline struct proc_dir_entry *proc_create_data(const char *name,
224 	mode_t mode, struct proc_dir_entry *parent,
225 	const struct file_operations *proc_fops, void *data)
226 {
227 	return NULL;
228 }
229 #define remove_proc_entry(name, parent) do {} while (0)
230 
231 static inline struct proc_dir_entry *proc_symlink(const char *name,
232 		struct proc_dir_entry *parent,const char *dest) {return NULL;}
233 static inline struct proc_dir_entry *proc_mkdir(const char *name,
234 	struct proc_dir_entry *parent) {return NULL;}
235 
236 static inline struct proc_dir_entry *create_proc_read_entry(const char *name,
237 	mode_t mode, struct proc_dir_entry *base,
238 	read_proc_t *read_proc, void * data) { return NULL; }
239 
240 struct tty_driver;
241 static inline void proc_tty_register_driver(struct tty_driver *driver) {};
242 static inline void proc_tty_unregister_driver(struct tty_driver *driver) {};
243 
244 static inline int pid_ns_prepare_proc(struct pid_namespace *ns)
245 {
246 	return 0;
247 }
248 
249 static inline void pid_ns_release_proc(struct pid_namespace *ns)
250 {
251 }
252 
253 static inline void set_mm_exe_file(struct mm_struct *mm,
254 				   struct file *new_exe_file)
255 {}
256 
257 static inline struct file *get_mm_exe_file(struct mm_struct *mm)
258 {
259 	return NULL;
260 }
261 
262 static inline void dup_mm_exe_file(struct mm_struct *oldmm,
263 	       			   struct mm_struct *newmm)
264 {}
265 
266 #endif /* CONFIG_PROC_FS */
267 
268 #if !defined(CONFIG_PROC_KCORE)
269 static inline void kclist_add(struct kcore_list *new, void *addr, size_t size)
270 {
271 }
272 #else
273 extern void kclist_add(struct kcore_list *, void *, size_t);
274 #endif
275 
276 union proc_op {
277 	int (*proc_get_link)(struct inode *, struct path *);
278 	int (*proc_read)(struct task_struct *task, char *page);
279 	int (*proc_show)(struct seq_file *m,
280 		struct pid_namespace *ns, struct pid *pid,
281 		struct task_struct *task);
282 };
283 
284 struct ctl_table_header;
285 struct ctl_table;
286 
287 struct proc_inode {
288 	struct pid *pid;
289 	int fd;
290 	union proc_op op;
291 	struct proc_dir_entry *pde;
292 	struct ctl_table_header *sysctl;
293 	struct ctl_table *sysctl_entry;
294 	struct inode vfs_inode;
295 };
296 
297 static inline struct proc_inode *PROC_I(const struct inode *inode)
298 {
299 	return container_of(inode, struct proc_inode, vfs_inode);
300 }
301 
302 static inline struct proc_dir_entry *PDE(const struct inode *inode)
303 {
304 	return PROC_I(inode)->pde;
305 }
306 
307 static inline struct net *PDE_NET(struct proc_dir_entry *pde)
308 {
309 	return pde->parent->data;
310 }
311 
312 struct proc_maps_private {
313 	struct pid *pid;
314 	struct task_struct *task;
315 #ifdef CONFIG_MMU
316 	struct vm_area_struct *tail_vma;
317 #endif
318 };
319 
320 #endif /* _LINUX_PROC_FS_H */
321