xref: /linux/include/linux/proc_fs.h (revision beace86e61e465dba204a268ab3f3377153a4973)
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 	struct dentry *proc_self;        /* For /proc/self */
70 	struct dentry *proc_thread_self; /* For /proc/thread-self */
71 	kgid_t pid_gid;
72 	enum proc_hidepid hide_pid;
73 	enum proc_pidonly pidonly;
74 	struct rcu_head rcu;
75 };
76 
77 static inline struct proc_fs_info *proc_sb_info(struct super_block *sb)
78 {
79 	return sb->s_fs_info;
80 }
81 
82 #ifdef CONFIG_PROC_FS
83 
84 typedef int (*proc_write_t)(struct file *, char *, size_t);
85 
86 extern void proc_root_init(void);
87 extern void proc_flush_pid(struct pid *);
88 
89 extern struct proc_dir_entry *proc_symlink(const char *,
90 		struct proc_dir_entry *, const char *);
91 struct proc_dir_entry *_proc_mkdir(const char *, umode_t, struct proc_dir_entry *, void *, bool);
92 extern struct proc_dir_entry *proc_mkdir(const char *, struct proc_dir_entry *);
93 extern struct proc_dir_entry *proc_mkdir_data(const char *, umode_t,
94 					      struct proc_dir_entry *, void *);
95 extern struct proc_dir_entry *proc_mkdir_mode(const char *, umode_t,
96 					      struct proc_dir_entry *);
97 struct proc_dir_entry *proc_create_mount_point(const char *name);
98 
99 struct proc_dir_entry *proc_create_seq_private(const char *name, umode_t mode,
100 		struct proc_dir_entry *parent, const struct seq_operations *ops,
101 		unsigned int state_size, void *data);
102 #define proc_create_seq_data(name, mode, parent, ops, data) \
103 	proc_create_seq_private(name, mode, parent, ops, 0, data)
104 #define proc_create_seq(name, mode, parent, ops) \
105 	proc_create_seq_private(name, mode, parent, ops, 0, NULL)
106 struct proc_dir_entry *proc_create_single_data(const char *name, umode_t mode,
107 		struct proc_dir_entry *parent,
108 		int (*show)(struct seq_file *, void *), void *data);
109 #define proc_create_single(name, mode, parent, show) \
110 	proc_create_single_data(name, mode, parent, show, NULL)
111 
112 extern struct proc_dir_entry *proc_create_data(const char *, umode_t,
113 					       struct proc_dir_entry *,
114 					       const struct proc_ops *,
115 					       void *);
116 
117 struct proc_dir_entry *proc_create(const char *name, umode_t mode, struct proc_dir_entry *parent, const struct proc_ops *proc_ops);
118 extern void proc_set_size(struct proc_dir_entry *, loff_t);
119 extern void proc_set_user(struct proc_dir_entry *, kuid_t, kgid_t);
120 
121 /*
122  * Obtain the private data passed by user through proc_create_data() or
123  * related.
124  */
125 static inline void *pde_data(const struct inode *inode)
126 {
127 	return inode->i_private;
128 }
129 
130 extern void *proc_get_parent_data(const struct inode *);
131 extern void proc_remove(struct proc_dir_entry *);
132 extern void remove_proc_entry(const char *, struct proc_dir_entry *);
133 extern int remove_proc_subtree(const char *, struct proc_dir_entry *);
134 
135 struct proc_dir_entry *proc_create_net_data(const char *name, umode_t mode,
136 		struct proc_dir_entry *parent, const struct seq_operations *ops,
137 		unsigned int state_size, void *data);
138 #define proc_create_net(name, mode, parent, ops, state_size) \
139 	proc_create_net_data(name, mode, parent, ops, state_size, NULL)
140 struct proc_dir_entry *proc_create_net_single(const char *name, umode_t mode,
141 		struct proc_dir_entry *parent,
142 		int (*show)(struct seq_file *, void *), void *data);
143 struct proc_dir_entry *proc_create_net_data_write(const char *name, umode_t mode,
144 						  struct proc_dir_entry *parent,
145 						  const struct seq_operations *ops,
146 						  proc_write_t write,
147 						  unsigned int state_size, void *data);
148 struct proc_dir_entry *proc_create_net_single_write(const char *name, umode_t mode,
149 						    struct proc_dir_entry *parent,
150 						    int (*show)(struct seq_file *, void *),
151 						    proc_write_t write,
152 						    void *data);
153 extern struct pid *tgid_pidfd_to_pid(const struct file *file);
154 
155 struct bpf_iter_aux_info;
156 extern int bpf_iter_init_seq_net(void *priv_data, struct bpf_iter_aux_info *aux);
157 extern void bpf_iter_fini_seq_net(void *priv_data);
158 
159 #ifdef CONFIG_PROC_PID_ARCH_STATUS
160 /*
161  * The architecture which selects CONFIG_PROC_PID_ARCH_STATUS must
162  * provide proc_pid_arch_status() definition.
163  */
164 int proc_pid_arch_status(struct seq_file *m, struct pid_namespace *ns,
165 			struct pid *pid, struct task_struct *task);
166 #endif /* CONFIG_PROC_PID_ARCH_STATUS */
167 
168 void arch_report_meminfo(struct seq_file *m);
169 void arch_proc_pid_thread_features(struct seq_file *m, struct task_struct *task);
170 
171 #else /* CONFIG_PROC_FS */
172 
173 static inline void proc_root_init(void)
174 {
175 }
176 
177 static inline void proc_flush_pid(struct pid *pid)
178 {
179 }
180 
181 static inline struct proc_dir_entry *proc_symlink(const char *name,
182 		struct proc_dir_entry *parent,const char *dest) { return NULL;}
183 static inline struct proc_dir_entry *proc_mkdir(const char *name,
184 	struct proc_dir_entry *parent) {return NULL;}
185 static inline struct proc_dir_entry *proc_create_mount_point(const char *name) { return NULL; }
186 static inline struct proc_dir_entry *_proc_mkdir(const char *name, umode_t mode,
187 		struct proc_dir_entry *parent, void *data, bool force_lookup)
188 {
189 	return NULL;
190 }
191 static inline struct proc_dir_entry *proc_mkdir_data(const char *name,
192 	umode_t mode, struct proc_dir_entry *parent, void *data) { return NULL; }
193 static inline struct proc_dir_entry *proc_mkdir_mode(const char *name,
194 	umode_t mode, struct proc_dir_entry *parent) { return NULL; }
195 #define proc_create_seq_private(name, mode, parent, ops, size, data) ({NULL;})
196 #define proc_create_seq_data(name, mode, parent, ops, data) ({NULL;})
197 #define proc_create_seq(name, mode, parent, ops) ({NULL;})
198 #define proc_create_single(name, mode, parent, show) ({NULL;})
199 #define proc_create_single_data(name, mode, parent, show, data) ({NULL;})
200 
201 static inline struct proc_dir_entry *
202 proc_create(const char *name, umode_t mode, struct proc_dir_entry *parent,
203 	    const struct proc_ops *proc_ops)
204 { return NULL; }
205 
206 static inline struct proc_dir_entry *
207 proc_create_data(const char *name, umode_t mode, struct proc_dir_entry *parent,
208 		 const struct proc_ops *proc_ops, void *data)
209 { return NULL; }
210 
211 static inline void proc_set_size(struct proc_dir_entry *de, loff_t size) {}
212 static inline void proc_set_user(struct proc_dir_entry *de, kuid_t uid, kgid_t gid) {}
213 static inline void *pde_data(const struct inode *inode) {BUG(); return NULL;}
214 static inline void *proc_get_parent_data(const struct inode *inode) { BUG(); return NULL; }
215 
216 static inline void proc_remove(struct proc_dir_entry *de) {}
217 #define remove_proc_entry(name, parent) do {} while (0)
218 static inline int remove_proc_subtree(const char *name, struct proc_dir_entry *parent) { return 0; }
219 
220 #define proc_create_net_data(name, mode, parent, ops, state_size, data) ({NULL;})
221 #define proc_create_net_data_write(name, mode, parent, ops, write, state_size, data) ({NULL;})
222 #define proc_create_net(name, mode, parent, state_size, ops) ({NULL;})
223 #define proc_create_net_single(name, mode, parent, show, data) ({NULL;})
224 #define proc_create_net_single_write(name, mode, parent, show, write, data) ({NULL;})
225 
226 static inline struct pid *tgid_pidfd_to_pid(const struct file *file)
227 {
228 	return ERR_PTR(-EBADF);
229 }
230 
231 #endif /* CONFIG_PROC_FS */
232 
233 struct net;
234 
235 static inline struct proc_dir_entry *proc_net_mkdir(
236 	struct net *net, const char *name, struct proc_dir_entry *parent)
237 {
238 	return _proc_mkdir(name, 0, parent, net, true);
239 }
240 
241 struct ns_common;
242 int open_related_ns(struct ns_common *ns,
243 		   struct ns_common *(*get_ns)(struct ns_common *ns));
244 
245 /* get the associated pid namespace for a file in procfs */
246 static inline struct pid_namespace *proc_pid_ns(struct super_block *sb)
247 {
248 	return proc_sb_info(sb)->pid_ns;
249 }
250 
251 bool proc_ns_file(const struct file *file);
252 
253 #endif /* _LINUX_PROC_FS_H */
254