xref: /openbmc/linux/fs/proc/internal.h (revision d2c43ff1)
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 #include <linux/sched/task.h>
19 
20 struct ctl_table_header;
21 struct mempolicy;
22 
23 /*
24  * This is not completely implemented yet. The idea is to
25  * create an in-memory tree (like the actual /proc filesystem
26  * tree) of these proc_dir_entries, so that we can dynamically
27  * add new files to /proc.
28  *
29  * parent/subdir are used for the directory structure (every /proc file has a
30  * parent, but "subdir" is empty for all non-directory entries).
31  * subdir_node is used to build the rb tree "subdir" of the parent.
32  */
33 struct proc_dir_entry {
34 	unsigned int low_ino;
35 	umode_t mode;
36 	nlink_t nlink;
37 	kuid_t uid;
38 	kgid_t gid;
39 	loff_t size;
40 	const struct inode_operations *proc_iops;
41 	const struct file_operations *proc_fops;
42 	struct proc_dir_entry *parent;
43 	struct rb_root subdir;
44 	struct rb_node subdir_node;
45 	void *data;
46 	atomic_t count;		/* use count */
47 	atomic_t in_use;	/* number of callers into module in progress; */
48 			/* negative -> it's going away RSN */
49 	struct completion *pde_unload_completion;
50 	struct list_head pde_openers;	/* who did ->open, but not ->release */
51 	spinlock_t pde_unload_lock; /* proc_fops checks and pde_users bumps */
52 	u8 namelen;
53 	char name[];
54 } __randomize_layout;
55 
56 union proc_op {
57 	int (*proc_get_link)(struct dentry *, struct path *);
58 	int (*proc_show)(struct seq_file *m,
59 		struct pid_namespace *ns, struct pid *pid,
60 		struct task_struct *task);
61 };
62 
63 struct proc_inode {
64 	struct pid *pid;
65 	unsigned int fd;
66 	union proc_op op;
67 	struct proc_dir_entry *pde;
68 	struct ctl_table_header *sysctl;
69 	struct ctl_table *sysctl_entry;
70 	struct hlist_node sysctl_inodes;
71 	const struct proc_ns_operations *ns_ops;
72 	struct inode vfs_inode;
73 } __randomize_layout;
74 
75 /*
76  * General functions
77  */
78 static inline struct proc_inode *PROC_I(const struct inode *inode)
79 {
80 	return container_of(inode, struct proc_inode, vfs_inode);
81 }
82 
83 static inline struct proc_dir_entry *PDE(const struct inode *inode)
84 {
85 	return PROC_I(inode)->pde;
86 }
87 
88 static inline void *__PDE_DATA(const struct inode *inode)
89 {
90 	return PDE(inode)->data;
91 }
92 
93 static inline struct pid *proc_pid(struct inode *inode)
94 {
95 	return PROC_I(inode)->pid;
96 }
97 
98 static inline struct task_struct *get_proc_task(struct inode *inode)
99 {
100 	return get_pid_task(proc_pid(inode), PIDTYPE_PID);
101 }
102 
103 void task_dump_owner(struct task_struct *task, mode_t mode,
104 		     kuid_t *ruid, kgid_t *rgid);
105 
106 static inline unsigned name_to_int(const struct qstr *qstr)
107 {
108 	const char *name = qstr->name;
109 	int len = qstr->len;
110 	unsigned n = 0;
111 
112 	if (len > 1 && *name == '0')
113 		goto out;
114 	while (len-- > 0) {
115 		unsigned c = *name++ - '0';
116 		if (c > 9)
117 			goto out;
118 		if (n >= (~0U-9)/10)
119 			goto out;
120 		n *= 10;
121 		n += c;
122 	}
123 	return n;
124 out:
125 	return ~0U;
126 }
127 
128 /*
129  * Offset of the first process in the /proc root directory..
130  */
131 #define FIRST_PROCESS_ENTRY 256
132 
133 /* Worst case buffer size needed for holding an integer. */
134 #define PROC_NUMBUF 13
135 
136 /*
137  * array.c
138  */
139 extern const struct file_operations proc_tid_children_operations;
140 
141 extern int proc_tid_stat(struct seq_file *, struct pid_namespace *,
142 			 struct pid *, struct task_struct *);
143 extern int proc_tgid_stat(struct seq_file *, struct pid_namespace *,
144 			  struct pid *, struct task_struct *);
145 extern int proc_pid_status(struct seq_file *, struct pid_namespace *,
146 			   struct pid *, struct task_struct *);
147 extern int proc_pid_statm(struct seq_file *, struct pid_namespace *,
148 			  struct pid *, struct task_struct *);
149 
150 /*
151  * base.c
152  */
153 extern const struct dentry_operations pid_dentry_operations;
154 extern int pid_getattr(const struct path *, struct kstat *, u32, unsigned int);
155 extern int proc_setattr(struct dentry *, struct iattr *);
156 extern struct inode *proc_pid_make_inode(struct super_block *, struct task_struct *, umode_t);
157 extern int pid_revalidate(struct dentry *, unsigned int);
158 extern int pid_delete_dentry(const struct dentry *);
159 extern int proc_pid_readdir(struct file *, struct dir_context *);
160 extern struct dentry *proc_pid_lookup(struct inode *, struct dentry *, unsigned int);
161 extern loff_t mem_lseek(struct file *, loff_t, int);
162 
163 /* Lookups */
164 typedef int instantiate_t(struct inode *, struct dentry *,
165 				     struct task_struct *, const void *);
166 extern bool proc_fill_cache(struct file *, struct dir_context *, const char *, int,
167 			   instantiate_t, struct task_struct *, const void *);
168 
169 /*
170  * generic.c
171  */
172 extern struct dentry *proc_lookup(struct inode *, struct dentry *, unsigned int);
173 extern struct dentry *proc_lookup_de(struct proc_dir_entry *, struct inode *,
174 				     struct dentry *);
175 extern int proc_readdir(struct file *, struct dir_context *);
176 extern int proc_readdir_de(struct proc_dir_entry *, struct file *, struct dir_context *);
177 
178 static inline struct proc_dir_entry *pde_get(struct proc_dir_entry *pde)
179 {
180 	atomic_inc(&pde->count);
181 	return pde;
182 }
183 extern void pde_put(struct proc_dir_entry *);
184 
185 static inline bool is_empty_pde(const struct proc_dir_entry *pde)
186 {
187 	return S_ISDIR(pde->mode) && !pde->proc_iops;
188 }
189 
190 /*
191  * inode.c
192  */
193 struct pde_opener {
194 	struct file *file;
195 	struct list_head lh;
196 	bool closing;
197 	struct completion *c;
198 };
199 extern const struct inode_operations proc_link_inode_operations;
200 
201 extern const struct inode_operations proc_pid_link_inode_operations;
202 
203 extern void proc_init_inodecache(void);
204 void set_proc_pid_nlink(void);
205 extern struct inode *proc_get_inode(struct super_block *, struct proc_dir_entry *);
206 extern int proc_fill_super(struct super_block *, void *data, int flags);
207 extern void proc_entry_rundown(struct proc_dir_entry *);
208 
209 /*
210  * proc_namespaces.c
211  */
212 extern const struct inode_operations proc_ns_dir_inode_operations;
213 extern const struct file_operations proc_ns_dir_operations;
214 
215 /*
216  * proc_net.c
217  */
218 extern const struct file_operations proc_net_operations;
219 extern const struct inode_operations proc_net_inode_operations;
220 
221 #ifdef CONFIG_NET
222 extern int proc_net_init(void);
223 #else
224 static inline int proc_net_init(void) { return 0; }
225 #endif
226 
227 /*
228  * proc_self.c
229  */
230 extern int proc_setup_self(struct super_block *);
231 
232 /*
233  * proc_thread_self.c
234  */
235 extern int proc_setup_thread_self(struct super_block *);
236 extern void proc_thread_self_init(void);
237 
238 /*
239  * proc_sysctl.c
240  */
241 #ifdef CONFIG_PROC_SYSCTL
242 extern int proc_sys_init(void);
243 extern void proc_sys_evict_inode(struct inode *inode,
244 				 struct ctl_table_header *head);
245 #else
246 static inline void proc_sys_init(void) { }
247 static inline void proc_sys_evict_inode(struct  inode *inode,
248 					struct ctl_table_header *head) { }
249 #endif
250 
251 /*
252  * proc_tty.c
253  */
254 #ifdef CONFIG_TTY
255 extern void proc_tty_init(void);
256 #else
257 static inline void proc_tty_init(void) {}
258 #endif
259 
260 /*
261  * root.c
262  */
263 extern struct proc_dir_entry proc_root;
264 extern int proc_parse_options(char *options, struct pid_namespace *pid);
265 
266 extern void proc_self_init(void);
267 extern int proc_remount(struct super_block *, int *, char *);
268 
269 /*
270  * task_[no]mmu.c
271  */
272 struct proc_maps_private {
273 	struct inode *inode;
274 	struct task_struct *task;
275 	struct mm_struct *mm;
276 #ifdef CONFIG_MMU
277 	struct vm_area_struct *tail_vma;
278 #endif
279 #ifdef CONFIG_NUMA
280 	struct mempolicy *task_mempolicy;
281 #endif
282 } __randomize_layout;
283 
284 struct mm_struct *proc_mem_open(struct inode *inode, unsigned int mode);
285 
286 extern const struct file_operations proc_pid_maps_operations;
287 extern const struct file_operations proc_tid_maps_operations;
288 extern const struct file_operations proc_pid_numa_maps_operations;
289 extern const struct file_operations proc_tid_numa_maps_operations;
290 extern const struct file_operations proc_pid_smaps_operations;
291 extern const struct file_operations proc_tid_smaps_operations;
292 extern const struct file_operations proc_clear_refs_operations;
293 extern const struct file_operations proc_pagemap_operations;
294 
295 extern unsigned long task_vsize(struct mm_struct *);
296 extern unsigned long task_statm(struct mm_struct *,
297 				unsigned long *, unsigned long *,
298 				unsigned long *, unsigned long *);
299 extern void task_mem(struct seq_file *, struct mm_struct *);
300