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/refcount.h>
15 #include <linux/spinlock.h>
16 #include <linux/atomic.h>
17 #include <linux/binfmts.h>
18 #include <linux/sched/coredump.h>
19 #include <linux/sched/task.h>
20 
21 struct ctl_table_header;
22 struct mempolicy;
23 
24 /*
25  * This is not completely implemented yet. The idea is to
26  * create an in-memory tree (like the actual /proc filesystem
27  * tree) of these proc_dir_entries, so that we can dynamically
28  * add new files to /proc.
29  *
30  * parent/subdir are used for the directory structure (every /proc file has a
31  * parent, but "subdir" is empty for all non-directory entries).
32  * subdir_node is used to build the rb tree "subdir" of the parent.
33  */
34 struct proc_dir_entry {
35 	/*
36 	 * number of callers into module in progress;
37 	 * negative -> it's going away RSN
38 	 */
39 	atomic_t in_use;
40 	refcount_t refcnt;
41 	struct list_head pde_openers;	/* who did ->open, but not ->release */
42 	/* protects ->pde_openers and all struct pde_opener instances */
43 	spinlock_t pde_unload_lock;
44 	struct completion *pde_unload_completion;
45 	const struct inode_operations *proc_iops;
46 	const struct file_operations *proc_fops;
47 	const struct dentry_operations *proc_dops;
48 	union {
49 		const struct seq_operations *seq_ops;
50 		int (*single_show)(struct seq_file *, void *);
51 	};
52 	proc_write_t write;
53 	void *data;
54 	unsigned int state_size;
55 	unsigned int low_ino;
56 	nlink_t nlink;
57 	kuid_t uid;
58 	kgid_t gid;
59 	loff_t size;
60 	struct proc_dir_entry *parent;
61 	struct rb_root subdir;
62 	struct rb_node subdir_node;
63 	char *name;
64 	umode_t mode;
65 	u8 namelen;
66 	char inline_name[];
67 } __randomize_layout;
68 
69 #define SIZEOF_PDE	(				\
70 	sizeof(struct proc_dir_entry) < 128 ? 128 :	\
71 	sizeof(struct proc_dir_entry) < 192 ? 192 :	\
72 	sizeof(struct proc_dir_entry) < 256 ? 256 :	\
73 	sizeof(struct proc_dir_entry) < 512 ? 512 :	\
74 	0)
75 #define SIZEOF_PDE_INLINE_NAME (SIZEOF_PDE - sizeof(struct proc_dir_entry))
76 
77 extern struct kmem_cache *proc_dir_entry_cache;
78 void pde_free(struct proc_dir_entry *pde);
79 
80 union proc_op {
81 	int (*proc_get_link)(struct dentry *, struct path *);
82 	int (*proc_show)(struct seq_file *m,
83 		struct pid_namespace *ns, struct pid *pid,
84 		struct task_struct *task);
85 };
86 
87 struct proc_inode {
88 	struct pid *pid;
89 	unsigned int fd;
90 	union proc_op op;
91 	struct proc_dir_entry *pde;
92 	struct ctl_table_header *sysctl;
93 	struct ctl_table *sysctl_entry;
94 	struct hlist_node sysctl_inodes;
95 	const struct proc_ns_operations *ns_ops;
96 	struct inode vfs_inode;
97 } __randomize_layout;
98 
99 /*
100  * General functions
101  */
PROC_I(const struct inode * inode)102 static inline struct proc_inode *PROC_I(const struct inode *inode)
103 {
104 	return container_of(inode, struct proc_inode, vfs_inode);
105 }
106 
PDE(const struct inode * inode)107 static inline struct proc_dir_entry *PDE(const struct inode *inode)
108 {
109 	return PROC_I(inode)->pde;
110 }
111 
__PDE_DATA(const struct inode * inode)112 static inline void *__PDE_DATA(const struct inode *inode)
113 {
114 	return PDE(inode)->data;
115 }
116 
proc_pid(const struct inode * inode)117 static inline struct pid *proc_pid(const struct inode *inode)
118 {
119 	return PROC_I(inode)->pid;
120 }
121 
get_proc_task(const struct inode * inode)122 static inline struct task_struct *get_proc_task(const struct inode *inode)
123 {
124 	return get_pid_task(proc_pid(inode), PIDTYPE_PID);
125 }
126 
127 void task_dump_owner(struct task_struct *task, umode_t mode,
128 		     kuid_t *ruid, kgid_t *rgid);
129 
130 unsigned name_to_int(const struct qstr *qstr);
131 /*
132  * Offset of the first process in the /proc root directory..
133  */
134 #define FIRST_PROCESS_ENTRY 256
135 
136 /* Worst case buffer size needed for holding an integer. */
137 #define PROC_NUMBUF 13
138 
139 /*
140  * array.c
141  */
142 extern const struct file_operations proc_tid_children_operations;
143 
144 extern void proc_task_name(struct seq_file *m, struct task_struct *p,
145 			   bool escape);
146 extern int proc_tid_stat(struct seq_file *, struct pid_namespace *,
147 			 struct pid *, struct task_struct *);
148 extern int proc_tgid_stat(struct seq_file *, struct pid_namespace *,
149 			  struct pid *, struct task_struct *);
150 extern int proc_pid_status(struct seq_file *, struct pid_namespace *,
151 			   struct pid *, struct task_struct *);
152 extern int proc_pid_statm(struct seq_file *, struct pid_namespace *,
153 			  struct pid *, struct task_struct *);
154 
155 /*
156  * base.c
157  */
158 extern const struct dentry_operations pid_dentry_operations;
159 extern int pid_getattr(const struct path *, struct kstat *, u32, unsigned int);
160 extern int proc_setattr(struct dentry *, struct iattr *);
161 extern struct inode *proc_pid_make_inode(struct super_block *, struct task_struct *, umode_t);
162 extern void pid_update_inode(struct task_struct *, struct inode *);
163 extern int pid_delete_dentry(const struct dentry *);
164 extern int proc_pid_readdir(struct file *, struct dir_context *);
165 extern struct dentry *proc_pid_lookup(struct inode *, struct dentry *, unsigned int);
166 extern loff_t mem_lseek(struct file *, loff_t, int);
167 
168 /* Lookups */
169 typedef struct dentry *instantiate_t(struct dentry *,
170 				     struct task_struct *, const void *);
171 bool proc_fill_cache(struct file *, struct dir_context *, const char *, unsigned int,
172 			   instantiate_t, struct task_struct *, const void *);
173 
174 /*
175  * generic.c
176  */
177 struct proc_dir_entry *proc_create_reg(const char *name, umode_t mode,
178 		struct proc_dir_entry **parent, void *data);
179 struct proc_dir_entry *proc_register(struct proc_dir_entry *dir,
180 		struct proc_dir_entry *dp);
181 extern struct dentry *proc_lookup(struct inode *, struct dentry *, unsigned int);
182 struct dentry *proc_lookup_de(struct inode *, struct dentry *, struct proc_dir_entry *);
183 extern int proc_readdir(struct file *, struct dir_context *);
184 int proc_readdir_de(struct file *, struct dir_context *, struct proc_dir_entry *);
185 
pde_get(struct proc_dir_entry * pde)186 static inline struct proc_dir_entry *pde_get(struct proc_dir_entry *pde)
187 {
188 	refcount_inc(&pde->refcnt);
189 	return pde;
190 }
191 extern void pde_put(struct proc_dir_entry *);
192 
is_empty_pde(const struct proc_dir_entry * pde)193 static inline bool is_empty_pde(const struct proc_dir_entry *pde)
194 {
195 	return S_ISDIR(pde->mode) && !pde->proc_iops;
196 }
197 extern ssize_t proc_simple_write(struct file *, const char __user *, size_t, loff_t *);
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 } __randomize_layout;
208 extern const struct inode_operations proc_link_inode_operations;
209 
210 extern const struct inode_operations proc_pid_link_inode_operations;
211 
212 void proc_init_kmemcache(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
proc_net_init(void)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 proc_sys_evict_inode(struct inode *inode,
253 				 struct ctl_table_header *head);
254 #else
proc_sys_init(void)255 static inline void proc_sys_init(void) { }
proc_sys_evict_inode(struct inode * inode,struct ctl_table_header * head)256 static inline void proc_sys_evict_inode(struct  inode *inode,
257 					struct ctl_table_header *head) { }
258 #endif
259 
260 /*
261  * proc_tty.c
262  */
263 #ifdef CONFIG_TTY
264 extern void proc_tty_init(void);
265 #else
proc_tty_init(void)266 static inline void proc_tty_init(void) {}
267 #endif
268 
269 /*
270  * root.c
271  */
272 extern struct proc_dir_entry proc_root;
273 extern int proc_parse_options(char *options, struct pid_namespace *pid);
274 
275 extern void proc_self_init(void);
276 extern int proc_remount(struct super_block *, int *, char *);
277 
278 /*
279  * task_[no]mmu.c
280  */
281 struct mem_size_stats;
282 struct proc_maps_private {
283 	struct inode *inode;
284 	struct task_struct *task;
285 	struct mm_struct *mm;
286 #ifdef CONFIG_MMU
287 	struct vm_area_struct *tail_vma;
288 #endif
289 #ifdef CONFIG_NUMA
290 	struct mempolicy *task_mempolicy;
291 #endif
292 } __randomize_layout;
293 
294 struct mm_struct *proc_mem_open(struct inode *inode, unsigned int mode);
295 
296 extern const struct file_operations proc_pid_maps_operations;
297 extern const struct file_operations proc_pid_numa_maps_operations;
298 extern const struct file_operations proc_pid_smaps_operations;
299 extern const struct file_operations proc_pid_smaps_rollup_operations;
300 extern const struct file_operations proc_clear_refs_operations;
301 extern const struct file_operations proc_pagemap_operations;
302 
303 extern unsigned long task_vsize(struct mm_struct *);
304 extern unsigned long task_statm(struct mm_struct *,
305 				unsigned long *, unsigned long *,
306 				unsigned long *, unsigned long *);
307 extern void task_mem(struct seq_file *, struct mm_struct *);
308 
309 extern const struct dentry_operations proc_net_dentry_ops;
pde_force_lookup(struct proc_dir_entry * pde)310 static inline void pde_force_lookup(struct proc_dir_entry *pde)
311 {
312 	/* /proc/net/ entries can be changed under us by setns(CLONE_NEWNET) */
313 	pde->proc_dops = &proc_net_dentry_ops;
314 }
315