xref: /linux/include/linux/proc_fs.h (revision a2a5eb6323a7b1987fd8048d94b9ffc7f87e3064)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  * The proc filesystem constants/structures
4  */
5 #ifndef _LINUX_PROC_FS_H
6 #define _LINUX_PROC_FS_H
7 
8 #include <linux/compiler.h>
9 #include <linux/types.h>
10 #include <linux/fs.h>
11 
12 struct proc_dir_entry;
13 struct seq_file;
14 struct seq_operations;
15 
16 enum {
17 	/*
18 	 * All /proc entries using this ->proc_ops instance are never removed.
19 	 *
20 	 * If in doubt, ignore this flag.
21 	 */
22 #ifdef MODULE
23 	PROC_ENTRY_PERMANENT		= 0U,
24 #else
25 	PROC_ENTRY_PERMANENT		= 1U << 0,
26 #endif
27 
28 	PROC_ENTRY_proc_read_iter	= 1U << 1,
29 	PROC_ENTRY_proc_compat_ioctl	= 1U << 2,
30 	PROC_ENTRY_proc_lseek		= 1U << 3,
31 
32 	PROC_ENTRY_FORCE_LOOKUP		= 1U << 7,
33 };
34 
35 struct proc_ops {
36 	unsigned int proc_flags;
37 	int	(*proc_open)(struct inode *, struct file *);
38 	ssize_t	(*proc_read)(struct file *, char __user *, size_t, loff_t *);
39 	ssize_t (*proc_read_iter)(struct kiocb *, struct iov_iter *);
40 	ssize_t	(*proc_write)(struct file *, const char __user *, size_t, loff_t *);
41 	/* mandatory unless nonseekable_open() or equivalent is used */
42 	loff_t	(*proc_lseek)(struct file *, loff_t, int);
43 	int	(*proc_release)(struct inode *, struct file *);
44 	__poll_t (*proc_poll)(struct file *, struct poll_table_struct *);
45 	long	(*proc_ioctl)(struct file *, unsigned int, unsigned long);
46 #ifdef CONFIG_COMPAT
47 	long	(*proc_compat_ioctl)(struct file *, unsigned int, unsigned long);
48 #endif
49 	int	(*proc_mmap)(struct file *, struct vm_area_struct *);
50 	unsigned long (*proc_get_unmapped_area)(struct file *, unsigned long, unsigned long, unsigned long, unsigned long);
51 } __randomize_layout;
52 
53 /* definitions for hide_pid field */
54 enum proc_hidepid {
55 	HIDEPID_OFF	  = 0,
56 	HIDEPID_NO_ACCESS = 1,
57 	HIDEPID_INVISIBLE = 2,
58 	HIDEPID_NOT_PTRACEABLE = 4, /* Limit pids to only ptraceable pids */
59 };
60 
61 /* definitions for proc mount option pidonly */
62 enum proc_pidonly {
63 	PROC_PIDONLY_OFF = 0,
64 	PROC_PIDONLY_ON  = 1,
65 };
66 
67 struct proc_fs_info {
68 	struct pid_namespace *pid_ns;
69 	kgid_t pid_gid;
70 	const struct cred *mounter_cred;
71 	enum proc_hidepid hide_pid;
72 	enum proc_pidonly pidonly;
73 	struct rcu_head rcu;
74 };
75 
76 static inline struct proc_fs_info *proc_sb_info(struct super_block *sb)
77 {
78 	return sb->s_fs_info;
79 }
80 
81 #ifdef CONFIG_PROC_FS
82 
83 typedef int (*proc_write_t)(struct file *, char *, size_t);
84 
85 extern void proc_root_init(void);
86 extern void proc_flush_pid(struct pid *);
87 
88 extern struct proc_dir_entry *proc_symlink(const char *,
89 		struct proc_dir_entry *, const char *);
90 struct proc_dir_entry *_proc_mkdir(const char *, umode_t, struct proc_dir_entry *, void *, bool);
91 extern struct proc_dir_entry *proc_mkdir(const char *, struct proc_dir_entry *);
92 extern struct proc_dir_entry *proc_mkdir_data(const char *, umode_t,
93 					      struct proc_dir_entry *, void *);
94 extern struct proc_dir_entry *proc_mkdir_mode(const char *, umode_t,
95 					      struct proc_dir_entry *);
96 struct proc_dir_entry *proc_create_mount_point(const char *name);
97 
98 struct proc_dir_entry *proc_create_seq_private(const char *name, umode_t mode,
99 		struct proc_dir_entry *parent, const struct seq_operations *ops,
100 		unsigned int state_size, void *data);
101 #define proc_create_seq_data(name, mode, parent, ops, data) \
102 	proc_create_seq_private(name, mode, parent, ops, 0, data)
103 #define proc_create_seq(name, mode, parent, ops) \
104 	proc_create_seq_private(name, mode, parent, ops, 0, NULL)
105 struct proc_dir_entry *proc_create_single_data(const char *name, umode_t mode,
106 		struct proc_dir_entry *parent,
107 		int (*show)(struct seq_file *, void *), void *data);
108 #define proc_create_single(name, mode, parent, show) \
109 	proc_create_single_data(name, mode, parent, show, NULL)
110 
111 extern struct proc_dir_entry *proc_create_data(const char *, umode_t,
112 					       struct proc_dir_entry *,
113 					       const struct proc_ops *,
114 					       void *);
115 
116 struct proc_dir_entry *proc_create(const char *name, umode_t mode, struct proc_dir_entry *parent, const struct proc_ops *proc_ops);
117 extern void proc_set_size(struct proc_dir_entry *, loff_t);
118 extern void proc_set_user(struct proc_dir_entry *, kuid_t, kgid_t);
119 
120 /*
121  * Obtain the private data passed by user through proc_create_data() or
122  * related.
123  */
124 static inline void *pde_data(const struct inode *inode)
125 {
126 	return inode->i_private;
127 }
128 
129 extern void *proc_get_parent_data(const struct inode *);
130 extern void proc_remove(struct proc_dir_entry *);
131 extern void remove_proc_entry(const char *, struct proc_dir_entry *);
132 extern int remove_proc_subtree(const char *, struct proc_dir_entry *);
133 
134 struct proc_dir_entry *proc_create_net_data(const char *name, umode_t mode,
135 		struct proc_dir_entry *parent, const struct seq_operations *ops,
136 		unsigned int state_size, void *data);
137 #define proc_create_net(name, mode, parent, ops, state_size) \
138 	proc_create_net_data(name, mode, parent, ops, state_size, NULL)
139 struct proc_dir_entry *proc_create_net_single(const char *name, umode_t mode,
140 		struct proc_dir_entry *parent,
141 		int (*show)(struct seq_file *, void *), void *data);
142 struct proc_dir_entry *proc_create_net_data_write(const char *name, umode_t mode,
143 						  struct proc_dir_entry *parent,
144 						  const struct seq_operations *ops,
145 						  proc_write_t write,
146 						  unsigned int state_size, void *data);
147 struct proc_dir_entry *proc_create_net_single_write(const char *name, umode_t mode,
148 						    struct proc_dir_entry *parent,
149 						    int (*show)(struct seq_file *, void *),
150 						    proc_write_t write,
151 						    void *data);
152 extern struct pid *tgid_pidfd_to_pid(const struct file *file);
153 
154 struct bpf_iter_aux_info;
155 extern int bpf_iter_init_seq_net(void *priv_data, struct bpf_iter_aux_info *aux);
156 extern void bpf_iter_fini_seq_net(void *priv_data);
157 
158 #ifdef CONFIG_PROC_PID_ARCH_STATUS
159 /*
160  * The architecture which selects CONFIG_PROC_PID_ARCH_STATUS must
161  * provide proc_pid_arch_status() definition.
162  */
163 int proc_pid_arch_status(struct seq_file *m, struct pid_namespace *ns,
164 			struct pid *pid, struct task_struct *task);
165 #endif /* CONFIG_PROC_PID_ARCH_STATUS */
166 
167 void arch_report_meminfo(struct seq_file *m);
168 void arch_proc_pid_thread_features(struct seq_file *m, struct task_struct *task);
169 
170 #else /* CONFIG_PROC_FS */
171 
172 static inline void proc_root_init(void)
173 {
174 }
175 
176 static inline void proc_flush_pid(struct pid *pid)
177 {
178 }
179 
180 static inline struct proc_dir_entry *proc_symlink(const char *name,
181 		struct proc_dir_entry *parent,const char *dest) { return NULL;}
182 static inline struct proc_dir_entry *proc_mkdir(const char *name,
183 	struct proc_dir_entry *parent) {return NULL;}
184 static inline struct proc_dir_entry *proc_create_mount_point(const char *name) { return NULL; }
185 static inline struct proc_dir_entry *_proc_mkdir(const char *name, umode_t mode,
186 		struct proc_dir_entry *parent, void *data, bool force_lookup)
187 {
188 	return NULL;
189 }
190 static inline struct proc_dir_entry *proc_mkdir_data(const char *name,
191 	umode_t mode, struct proc_dir_entry *parent, void *data) { return NULL; }
192 static inline struct proc_dir_entry *proc_mkdir_mode(const char *name,
193 	umode_t mode, struct proc_dir_entry *parent) { return NULL; }
194 #define proc_create_seq_private(name, mode, parent, ops, size, data) ({NULL;})
195 #define proc_create_seq_data(name, mode, parent, ops, data) ({NULL;})
196 #define proc_create_seq(name, mode, parent, ops) ({NULL;})
197 #define proc_create_single(name, mode, parent, show) ({NULL;})
198 #define proc_create_single_data(name, mode, parent, show, data) ({NULL;})
199 
200 static inline struct proc_dir_entry *
201 proc_create(const char *name, umode_t mode, struct proc_dir_entry *parent,
202 	    const struct proc_ops *proc_ops)
203 { return NULL; }
204 
205 static inline struct proc_dir_entry *
206 proc_create_data(const char *name, umode_t mode, struct proc_dir_entry *parent,
207 		 const struct proc_ops *proc_ops, void *data)
208 { return NULL; }
209 
210 static inline void proc_set_size(struct proc_dir_entry *de, loff_t size) {}
211 static inline void proc_set_user(struct proc_dir_entry *de, kuid_t uid, kgid_t gid) {}
212 static inline void *pde_data(const struct inode *inode) {BUG(); return NULL;}
213 static inline void *proc_get_parent_data(const struct inode *inode) { BUG(); return NULL; }
214 
215 static inline void proc_remove(struct proc_dir_entry *de) {}
216 #define remove_proc_entry(name, parent) do {} while (0)
217 static inline int remove_proc_subtree(const char *name, struct proc_dir_entry *parent) { return 0; }
218 
219 #define proc_create_net_data(name, mode, parent, ops, state_size, data) ({NULL;})
220 #define proc_create_net_data_write(name, mode, parent, ops, write, state_size, data) ({NULL;})
221 #define proc_create_net(name, mode, parent, state_size, ops) ({NULL;})
222 #define proc_create_net_single(name, mode, parent, show, data) ({NULL;})
223 #define proc_create_net_single_write(name, mode, parent, show, write, data) ({NULL;})
224 
225 static inline struct pid *tgid_pidfd_to_pid(const struct file *file)
226 {
227 	return ERR_PTR(-EBADF);
228 }
229 
230 #endif /* CONFIG_PROC_FS */
231 
232 struct net;
233 
234 static inline struct proc_dir_entry *proc_net_mkdir(
235 	struct net *net, const char *name, struct proc_dir_entry *parent)
236 {
237 	return _proc_mkdir(name, 0, parent, net, true);
238 }
239 
240 struct ns_common;
241 int open_related_ns(struct ns_common *ns,
242 		   struct ns_common *(*get_ns)(struct ns_common *ns));
243 
244 /* get the associated pid namespace for a file in procfs */
245 static inline struct pid_namespace *proc_pid_ns(struct super_block *sb)
246 {
247 	return proc_sb_info(sb)->pid_ns;
248 }
249 
250 bool proc_ns_file(const struct file *file);
251 
252 #if defined CONFIG_PROC_FS && !defined MODULE
253 void impl_proc_make_permanent(struct proc_dir_entry *pde);
254 #endif
255 
256 static inline void proc_make_permanent(struct proc_dir_entry *pde)
257 {
258 	/* Don't give matches to modules. */
259 #if defined CONFIG_PROC_FS && !defined MODULE
260 	impl_proc_make_permanent(pde);
261 #endif
262 }
263 
264 #endif /* _LINUX_PROC_FS_H */
265