xref: /openbmc/linux/fs/proc/internal.h (revision 174cd4b1)
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 #include <linux/sched/coredump.h>
18 
19 struct ctl_table_header;
20 struct mempolicy;
21 
22 /*
23  * This is not completely implemented yet. The idea is to
24  * create an in-memory tree (like the actual /proc filesystem
25  * tree) of these proc_dir_entries, so that we can dynamically
26  * add new files to /proc.
27  *
28  * parent/subdir are used for the directory structure (every /proc file has a
29  * parent, but "subdir" is empty for all non-directory entries).
30  * subdir_node is used to build the rb tree "subdir" of the parent.
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 *parent;
42 	struct rb_root subdir;
43 	struct rb_node subdir_node;
44 	void *data;
45 	atomic_t count;		/* use count */
46 	atomic_t in_use;	/* number of callers into module in progress; */
47 			/* negative -> it's going away RSN */
48 	struct completion *pde_unload_completion;
49 	struct list_head pde_openers;	/* who did ->open, but not ->release */
50 	spinlock_t pde_unload_lock; /* proc_fops checks and pde_users bumps */
51 	u8 namelen;
52 	char name[];
53 };
54 
55 union proc_op {
56 	int (*proc_get_link)(struct dentry *, struct path *);
57 	int (*proc_show)(struct seq_file *m,
58 		struct pid_namespace *ns, struct pid *pid,
59 		struct task_struct *task);
60 };
61 
62 struct proc_inode {
63 	struct pid *pid;
64 	unsigned int fd;
65 	union proc_op op;
66 	struct proc_dir_entry *pde;
67 	struct ctl_table_header *sysctl;
68 	struct ctl_table *sysctl_entry;
69 	struct list_head sysctl_inodes;
70 	const struct proc_ns_operations *ns_ops;
71 	struct inode vfs_inode;
72 };
73 
74 /*
75  * General functions
76  */
77 static inline struct proc_inode *PROC_I(const struct inode *inode)
78 {
79 	return container_of(inode, struct proc_inode, vfs_inode);
80 }
81 
82 static inline struct proc_dir_entry *PDE(const struct inode *inode)
83 {
84 	return PROC_I(inode)->pde;
85 }
86 
87 static inline void *__PDE_DATA(const struct inode *inode)
88 {
89 	return PDE(inode)->data;
90 }
91 
92 static inline struct pid *proc_pid(struct inode *inode)
93 {
94 	return PROC_I(inode)->pid;
95 }
96 
97 static inline struct task_struct *get_proc_task(struct inode *inode)
98 {
99 	return get_pid_task(proc_pid(inode), PIDTYPE_PID);
100 }
101 
102 void task_dump_owner(struct task_struct *task, mode_t mode,
103 		     kuid_t *ruid, kgid_t *rgid);
104 
105 static inline unsigned name_to_int(const struct qstr *qstr)
106 {
107 	const char *name = qstr->name;
108 	int len = qstr->len;
109 	unsigned n = 0;
110 
111 	if (len > 1 && *name == '0')
112 		goto out;
113 	while (len-- > 0) {
114 		unsigned c = *name++ - '0';
115 		if (c > 9)
116 			goto out;
117 		if (n >= (~0U-9)/10)
118 			goto out;
119 		n *= 10;
120 		n += c;
121 	}
122 	return n;
123 out:
124 	return ~0U;
125 }
126 
127 /*
128  * Offset of the first process in the /proc root directory..
129  */
130 #define FIRST_PROCESS_ENTRY 256
131 
132 /* Worst case buffer size needed for holding an integer. */
133 #define PROC_NUMBUF 13
134 
135 /*
136  * array.c
137  */
138 extern const struct file_operations proc_tid_children_operations;
139 
140 extern int proc_tid_stat(struct seq_file *, struct pid_namespace *,
141 			 struct pid *, struct task_struct *);
142 extern int proc_tgid_stat(struct seq_file *, struct pid_namespace *,
143 			  struct pid *, struct task_struct *);
144 extern int proc_pid_status(struct seq_file *, struct pid_namespace *,
145 			   struct pid *, struct task_struct *);
146 extern int proc_pid_statm(struct seq_file *, struct pid_namespace *,
147 			  struct pid *, struct task_struct *);
148 
149 /*
150  * base.c
151  */
152 extern const struct dentry_operations pid_dentry_operations;
153 extern int pid_getattr(struct vfsmount *, struct dentry *, struct kstat *);
154 extern int proc_setattr(struct dentry *, struct iattr *);
155 extern struct inode *proc_pid_make_inode(struct super_block *, struct task_struct *, umode_t);
156 extern int pid_revalidate(struct dentry *, unsigned int);
157 extern int pid_delete_dentry(const struct dentry *);
158 extern int proc_pid_readdir(struct file *, struct dir_context *);
159 extern struct dentry *proc_pid_lookup(struct inode *, struct dentry *, unsigned int);
160 extern loff_t mem_lseek(struct file *, loff_t, int);
161 
162 /* Lookups */
163 typedef int instantiate_t(struct inode *, struct dentry *,
164 				     struct task_struct *, const void *);
165 extern bool proc_fill_cache(struct file *, struct dir_context *, const char *, int,
166 			   instantiate_t, struct task_struct *, const void *);
167 
168 /*
169  * generic.c
170  */
171 extern struct dentry *proc_lookup(struct inode *, struct dentry *, unsigned int);
172 extern struct dentry *proc_lookup_de(struct proc_dir_entry *, struct inode *,
173 				     struct dentry *);
174 extern int proc_readdir(struct file *, struct dir_context *);
175 extern int proc_readdir_de(struct proc_dir_entry *, struct file *, struct dir_context *);
176 
177 static inline struct proc_dir_entry *pde_get(struct proc_dir_entry *pde)
178 {
179 	atomic_inc(&pde->count);
180 	return pde;
181 }
182 extern void pde_put(struct proc_dir_entry *);
183 
184 static inline bool is_empty_pde(const struct proc_dir_entry *pde)
185 {
186 	return S_ISDIR(pde->mode) && !pde->proc_iops;
187 }
188 
189 /*
190  * inode.c
191  */
192 struct pde_opener {
193 	struct file *file;
194 	struct list_head lh;
195 	bool closing;
196 	struct completion *c;
197 };
198 extern const struct inode_operations proc_link_inode_operations;
199 
200 extern const struct inode_operations proc_pid_link_inode_operations;
201 
202 extern void proc_init_inodecache(void);
203 void set_proc_pid_nlink(void);
204 extern struct inode *proc_get_inode(struct super_block *, struct proc_dir_entry *);
205 extern int proc_fill_super(struct super_block *, void *data, int flags);
206 extern void proc_entry_rundown(struct proc_dir_entry *);
207 
208 /*
209  * proc_namespaces.c
210  */
211 extern const struct inode_operations proc_ns_dir_inode_operations;
212 extern const struct file_operations proc_ns_dir_operations;
213 
214 /*
215  * proc_net.c
216  */
217 extern const struct file_operations proc_net_operations;
218 extern const struct inode_operations proc_net_inode_operations;
219 
220 #ifdef CONFIG_NET
221 extern int proc_net_init(void);
222 #else
223 static inline int proc_net_init(void) { return 0; }
224 #endif
225 
226 /*
227  * proc_self.c
228  */
229 extern int proc_setup_self(struct super_block *);
230 
231 /*
232  * proc_thread_self.c
233  */
234 extern int proc_setup_thread_self(struct super_block *);
235 extern void proc_thread_self_init(void);
236 
237 /*
238  * proc_sysctl.c
239  */
240 #ifdef CONFIG_PROC_SYSCTL
241 extern int proc_sys_init(void);
242 extern void proc_sys_evict_inode(struct inode *inode,
243 				 struct ctl_table_header *head);
244 #else
245 static inline void proc_sys_init(void) { }
246 static inline void proc_sys_evict_inode(struct  inode *inode,
247 					struct ctl_table_header *head) { }
248 #endif
249 
250 /*
251  * proc_tty.c
252  */
253 #ifdef CONFIG_TTY
254 extern void proc_tty_init(void);
255 #else
256 static inline void proc_tty_init(void) {}
257 #endif
258 
259 /*
260  * root.c
261  */
262 extern struct proc_dir_entry proc_root;
263 extern int proc_parse_options(char *options, struct pid_namespace *pid);
264 
265 extern void proc_self_init(void);
266 extern int proc_remount(struct super_block *, int *, char *);
267 
268 /*
269  * task_[no]mmu.c
270  */
271 struct proc_maps_private {
272 	struct inode *inode;
273 	struct task_struct *task;
274 	struct mm_struct *mm;
275 #ifdef CONFIG_MMU
276 	struct vm_area_struct *tail_vma;
277 #endif
278 #ifdef CONFIG_NUMA
279 	struct mempolicy *task_mempolicy;
280 #endif
281 };
282 
283 struct mm_struct *proc_mem_open(struct inode *inode, unsigned int mode);
284 
285 extern const struct file_operations proc_pid_maps_operations;
286 extern const struct file_operations proc_tid_maps_operations;
287 extern const struct file_operations proc_pid_numa_maps_operations;
288 extern const struct file_operations proc_tid_numa_maps_operations;
289 extern const struct file_operations proc_pid_smaps_operations;
290 extern const struct file_operations proc_tid_smaps_operations;
291 extern const struct file_operations proc_clear_refs_operations;
292 extern const struct file_operations proc_pagemap_operations;
293 
294 extern unsigned long task_vsize(struct mm_struct *);
295 extern unsigned long task_statm(struct mm_struct *,
296 				unsigned long *, unsigned long *,
297 				unsigned long *, unsigned long *);
298 extern void task_mem(struct seq_file *, struct mm_struct *);
299