xref: /linux/fs/proc/internal.h (revision 80d443e8876602be2c130f79c4de81e12e2a700d)
1 /* Internal procfs definitions
2  *
3  * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
4  * Written by David Howells (dhowells@redhat.com)
5  *
6  * This program is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU General Public License
8  * as published by the Free Software Foundation; either version
9  * 2 of the License, or (at your option) any later version.
10  */
11 
12 #include <linux/proc_fs.h>
13 #include <linux/proc_ns.h>
14 #include <linux/spinlock.h>
15 #include <linux/atomic.h>
16 #include <linux/binfmts.h>
17 
18 struct ctl_table_header;
19 struct mempolicy;
20 
21 /*
22  * This is not completely implemented yet. The idea is to
23  * create an in-memory tree (like the actual /proc filesystem
24  * tree) of these proc_dir_entries, so that we can dynamically
25  * add new files to /proc.
26  *
27  * parent/subdir are used for the directory structure (every /proc file has a
28  * parent, but "subdir" is empty for all non-directory entries).
29  * subdir_node is used to build the rb tree "subdir" of the parent.
30  */
31 struct proc_dir_entry {
32 	unsigned int low_ino;
33 	umode_t mode;
34 	nlink_t nlink;
35 	kuid_t uid;
36 	kgid_t gid;
37 	loff_t size;
38 	const struct inode_operations *proc_iops;
39 	const struct file_operations *proc_fops;
40 	struct proc_dir_entry *parent;
41 	struct rb_root subdir;
42 	struct rb_node subdir_node;
43 	void *data;
44 	atomic_t count;		/* use count */
45 	atomic_t in_use;	/* number of callers into module in progress; */
46 			/* negative -> it's going away RSN */
47 	struct completion *pde_unload_completion;
48 	struct list_head pde_openers;	/* who did ->open, but not ->release */
49 	spinlock_t pde_unload_lock; /* proc_fops checks and pde_users bumps */
50 	u8 namelen;
51 	char name[];
52 };
53 
54 union proc_op {
55 	int (*proc_get_link)(struct dentry *, struct path *);
56 	int (*proc_show)(struct seq_file *m,
57 		struct pid_namespace *ns, struct pid *pid,
58 		struct task_struct *task);
59 };
60 
61 struct proc_inode {
62 	struct pid *pid;
63 	unsigned int fd;
64 	union proc_op op;
65 	struct proc_dir_entry *pde;
66 	struct ctl_table_header *sysctl;
67 	struct ctl_table *sysctl_entry;
68 	const struct proc_ns_operations *ns_ops;
69 	struct inode vfs_inode;
70 };
71 
72 /*
73  * General functions
74  */
75 static inline struct proc_inode *PROC_I(const struct inode *inode)
76 {
77 	return container_of(inode, struct proc_inode, vfs_inode);
78 }
79 
80 static inline struct proc_dir_entry *PDE(const struct inode *inode)
81 {
82 	return PROC_I(inode)->pde;
83 }
84 
85 static inline void *__PDE_DATA(const struct inode *inode)
86 {
87 	return PDE(inode)->data;
88 }
89 
90 static inline struct pid *proc_pid(struct inode *inode)
91 {
92 	return PROC_I(inode)->pid;
93 }
94 
95 static inline struct task_struct *get_proc_task(struct inode *inode)
96 {
97 	return get_pid_task(proc_pid(inode), PIDTYPE_PID);
98 }
99 
100 static inline int task_dumpable(struct task_struct *task)
101 {
102 	int dumpable = 0;
103 	struct mm_struct *mm;
104 
105 	task_lock(task);
106 	mm = task->mm;
107 	if (mm)
108 		dumpable = get_dumpable(mm);
109 	task_unlock(task);
110 	if (dumpable == SUID_DUMP_USER)
111 		return 1;
112 	return 0;
113 }
114 
115 static inline unsigned name_to_int(const struct qstr *qstr)
116 {
117 	const char *name = qstr->name;
118 	int len = qstr->len;
119 	unsigned n = 0;
120 
121 	if (len > 1 && *name == '0')
122 		goto out;
123 	while (len-- > 0) {
124 		unsigned c = *name++ - '0';
125 		if (c > 9)
126 			goto out;
127 		if (n >= (~0U-9)/10)
128 			goto out;
129 		n *= 10;
130 		n += c;
131 	}
132 	return n;
133 out:
134 	return ~0U;
135 }
136 
137 /*
138  * Offset of the first process in the /proc root directory..
139  */
140 #define FIRST_PROCESS_ENTRY 256
141 
142 /* Worst case buffer size needed for holding an integer. */
143 #define PROC_NUMBUF 13
144 
145 /*
146  * array.c
147  */
148 extern const struct file_operations proc_tid_children_operations;
149 
150 extern int proc_tid_stat(struct seq_file *, struct pid_namespace *,
151 			 struct pid *, struct task_struct *);
152 extern int proc_tgid_stat(struct seq_file *, struct pid_namespace *,
153 			  struct pid *, struct task_struct *);
154 extern int proc_pid_status(struct seq_file *, struct pid_namespace *,
155 			   struct pid *, struct task_struct *);
156 extern int proc_pid_statm(struct seq_file *, struct pid_namespace *,
157 			  struct pid *, struct task_struct *);
158 
159 /*
160  * base.c
161  */
162 extern const struct dentry_operations pid_dentry_operations;
163 extern int pid_getattr(struct vfsmount *, struct dentry *, struct kstat *);
164 extern int proc_setattr(struct dentry *, struct iattr *);
165 extern struct inode *proc_pid_make_inode(struct super_block *, struct task_struct *, umode_t);
166 extern int pid_revalidate(struct dentry *, unsigned int);
167 extern int pid_delete_dentry(const struct dentry *);
168 extern int proc_pid_readdir(struct file *, struct dir_context *);
169 extern struct dentry *proc_pid_lookup(struct inode *, struct dentry *, unsigned int);
170 extern loff_t mem_lseek(struct file *, loff_t, int);
171 
172 /* Lookups */
173 typedef int instantiate_t(struct inode *, struct dentry *,
174 				     struct task_struct *, const void *);
175 extern bool proc_fill_cache(struct file *, struct dir_context *, const char *, int,
176 			   instantiate_t, struct task_struct *, const void *);
177 
178 /*
179  * generic.c
180  */
181 extern struct dentry *proc_lookup(struct inode *, struct dentry *, unsigned int);
182 extern struct dentry *proc_lookup_de(struct proc_dir_entry *, struct inode *,
183 				     struct dentry *);
184 extern int proc_readdir(struct file *, struct dir_context *);
185 extern int proc_readdir_de(struct proc_dir_entry *, struct file *, struct dir_context *);
186 
187 static inline struct proc_dir_entry *pde_get(struct proc_dir_entry *pde)
188 {
189 	atomic_inc(&pde->count);
190 	return pde;
191 }
192 extern void pde_put(struct proc_dir_entry *);
193 
194 static inline bool is_empty_pde(const struct proc_dir_entry *pde)
195 {
196 	return S_ISDIR(pde->mode) && !pde->proc_iops;
197 }
198 
199 /*
200  * inode.c
201  */
202 struct pde_opener {
203 	struct file *file;
204 	struct list_head lh;
205 	bool closing;
206 	struct completion *c;
207 };
208 extern const struct inode_operations proc_link_inode_operations;
209 
210 extern const struct inode_operations proc_pid_link_inode_operations;
211 
212 extern void proc_init_inodecache(void);
213 void set_proc_pid_nlink(void);
214 extern struct inode *proc_get_inode(struct super_block *, struct proc_dir_entry *);
215 extern int proc_fill_super(struct super_block *, void *data, int flags);
216 extern void proc_entry_rundown(struct proc_dir_entry *);
217 
218 /*
219  * proc_namespaces.c
220  */
221 extern const struct inode_operations proc_ns_dir_inode_operations;
222 extern const struct file_operations proc_ns_dir_operations;
223 
224 /*
225  * proc_net.c
226  */
227 extern const struct file_operations proc_net_operations;
228 extern const struct inode_operations proc_net_inode_operations;
229 
230 #ifdef CONFIG_NET
231 extern int proc_net_init(void);
232 #else
233 static inline int proc_net_init(void) { return 0; }
234 #endif
235 
236 /*
237  * proc_self.c
238  */
239 extern int proc_setup_self(struct super_block *);
240 
241 /*
242  * proc_thread_self.c
243  */
244 extern int proc_setup_thread_self(struct super_block *);
245 extern void proc_thread_self_init(void);
246 
247 /*
248  * proc_sysctl.c
249  */
250 #ifdef CONFIG_PROC_SYSCTL
251 extern int proc_sys_init(void);
252 extern void sysctl_head_put(struct ctl_table_header *);
253 #else
254 static inline void proc_sys_init(void) { }
255 static inline void sysctl_head_put(struct ctl_table_header *head) { }
256 #endif
257 
258 /*
259  * proc_tty.c
260  */
261 #ifdef CONFIG_TTY
262 extern void proc_tty_init(void);
263 #else
264 static inline void proc_tty_init(void) {}
265 #endif
266 
267 /*
268  * root.c
269  */
270 extern struct proc_dir_entry proc_root;
271 extern int proc_parse_options(char *options, struct pid_namespace *pid);
272 
273 extern void proc_self_init(void);
274 extern int proc_remount(struct super_block *, int *, char *);
275 
276 /*
277  * task_[no]mmu.c
278  */
279 struct proc_maps_private {
280 	struct inode *inode;
281 	struct task_struct *task;
282 	struct mm_struct *mm;
283 #ifdef CONFIG_MMU
284 	struct vm_area_struct *tail_vma;
285 #endif
286 #ifdef CONFIG_NUMA
287 	struct mempolicy *task_mempolicy;
288 #endif
289 };
290 
291 struct mm_struct *proc_mem_open(struct inode *inode, unsigned int mode);
292 
293 extern const struct file_operations proc_pid_maps_operations;
294 extern const struct file_operations proc_tid_maps_operations;
295 extern const struct file_operations proc_pid_numa_maps_operations;
296 extern const struct file_operations proc_tid_numa_maps_operations;
297 extern const struct file_operations proc_pid_smaps_operations;
298 extern const struct file_operations proc_tid_smaps_operations;
299 extern const struct file_operations proc_clear_refs_operations;
300 extern const struct file_operations proc_pagemap_operations;
301 
302 extern unsigned long task_vsize(struct mm_struct *);
303 extern unsigned long task_statm(struct mm_struct *,
304 				unsigned long *, unsigned long *,
305 				unsigned long *, unsigned long *);
306 extern void task_mem(struct seq_file *, struct mm_struct *);
307