xref: /linux/fs/proc/internal.h (revision 2fe5de9ce7d57498abc14b375cad2fcf8c3ee6cc)
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  * The "next" pointer creates a linked list of one /proc directory,
28  * while parent/subdir create the directory structure (every
29  * /proc file has a parent, but "subdir" is NULL for all
30  * non-directory entries).
31  */
32 struct proc_dir_entry {
33 	unsigned int low_ino;
34 	umode_t mode;
35 	nlink_t nlink;
36 	kuid_t uid;
37 	kgid_t gid;
38 	loff_t size;
39 	const struct inode_operations *proc_iops;
40 	const struct file_operations *proc_fops;
41 	struct proc_dir_entry *next, *parent, *subdir;
42 	void *data;
43 	atomic_t count;		/* use count */
44 	atomic_t in_use;	/* number of callers into module in progress; */
45 			/* negative -> it's going away RSN */
46 	struct completion *pde_unload_completion;
47 	struct list_head pde_openers;	/* who did ->open, but not ->release */
48 	spinlock_t pde_unload_lock; /* proc_fops checks and pde_users bumps */
49 	u8 namelen;
50 	char name[];
51 };
52 
53 union proc_op {
54 	int (*proc_get_link)(struct dentry *, struct path *);
55 	int (*proc_read)(struct task_struct *task, char *page);
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 	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 	struct proc_ns ns;
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(struct dentry *dentry)
116 {
117 	const char *name = dentry->d_name.name;
118 	int len = dentry->d_name.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 *);
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 spinlock_t proc_subdir_lock;
182 
183 extern struct dentry *proc_lookup(struct inode *, struct dentry *, unsigned int);
184 extern struct dentry *proc_lookup_de(struct proc_dir_entry *, struct inode *,
185 				     struct dentry *);
186 extern int proc_readdir(struct file *, struct dir_context *);
187 extern int proc_readdir_de(struct proc_dir_entry *, struct file *, struct dir_context *);
188 
189 static inline struct proc_dir_entry *pde_get(struct proc_dir_entry *pde)
190 {
191 	atomic_inc(&pde->count);
192 	return pde;
193 }
194 extern void pde_put(struct proc_dir_entry *);
195 
196 /*
197  * inode.c
198  */
199 struct pde_opener {
200 	struct file *file;
201 	struct list_head lh;
202 	int closing;
203 	struct completion *c;
204 };
205 
206 extern const struct inode_operations proc_pid_link_inode_operations;
207 
208 extern void proc_init_inodecache(void);
209 extern struct inode *proc_get_inode(struct super_block *, struct proc_dir_entry *);
210 extern int proc_fill_super(struct super_block *);
211 extern void proc_entry_rundown(struct proc_dir_entry *);
212 
213 /*
214  * proc_namespaces.c
215  */
216 extern const struct inode_operations proc_ns_dir_inode_operations;
217 extern const struct file_operations proc_ns_dir_operations;
218 
219 /*
220  * proc_net.c
221  */
222 extern const struct file_operations proc_net_operations;
223 extern const struct inode_operations proc_net_inode_operations;
224 
225 #ifdef CONFIG_NET
226 extern int proc_net_init(void);
227 #else
228 static inline int proc_net_init(void) { return 0; }
229 #endif
230 
231 /*
232  * proc_self.c
233  */
234 extern int proc_setup_self(struct super_block *);
235 
236 /*
237  * proc_sysctl.c
238  */
239 #ifdef CONFIG_PROC_SYSCTL
240 extern int proc_sys_init(void);
241 extern void sysctl_head_put(struct ctl_table_header *);
242 #else
243 static inline void proc_sys_init(void) { }
244 static inline void sysctl_head_put(struct ctl_table_header *head) { }
245 #endif
246 
247 /*
248  * proc_tty.c
249  */
250 #ifdef CONFIG_TTY
251 extern void proc_tty_init(void);
252 #else
253 static inline void proc_tty_init(void) {}
254 #endif
255 
256 /*
257  * root.c
258  */
259 extern struct proc_dir_entry proc_root;
260 
261 extern void proc_self_init(void);
262 extern int proc_remount(struct super_block *, int *, char *);
263 
264 /*
265  * task_[no]mmu.c
266  */
267 struct proc_maps_private {
268 	struct pid *pid;
269 	struct task_struct *task;
270 #ifdef CONFIG_MMU
271 	struct vm_area_struct *tail_vma;
272 #endif
273 #ifdef CONFIG_NUMA
274 	struct mempolicy *task_mempolicy;
275 #endif
276 };
277 
278 extern const struct file_operations proc_pid_maps_operations;
279 extern const struct file_operations proc_tid_maps_operations;
280 extern const struct file_operations proc_pid_numa_maps_operations;
281 extern const struct file_operations proc_tid_numa_maps_operations;
282 extern const struct file_operations proc_pid_smaps_operations;
283 extern const struct file_operations proc_tid_smaps_operations;
284 extern const struct file_operations proc_clear_refs_operations;
285 extern const struct file_operations proc_pagemap_operations;
286 
287 extern unsigned long task_vsize(struct mm_struct *);
288 extern unsigned long task_statm(struct mm_struct *,
289 				unsigned long *, unsigned long *,
290 				unsigned long *, unsigned long *);
291 extern void task_mem(struct seq_file *, struct mm_struct *);
292