xref: /openbmc/linux/fs/proc/internal.h (revision b593bce5)
1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /* Internal procfs definitions
3  *
4  * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
5  * Written by David Howells (dhowells@redhat.com)
6  */
7 
8 #include <linux/proc_fs.h>
9 #include <linux/proc_ns.h>
10 #include <linux/refcount.h>
11 #include <linux/spinlock.h>
12 #include <linux/atomic.h>
13 #include <linux/binfmts.h>
14 #include <linux/sched/coredump.h>
15 #include <linux/sched/task.h>
16 
17 struct ctl_table_header;
18 struct mempolicy;
19 
20 /*
21  * This is not completely implemented yet. The idea is to
22  * create an in-memory tree (like the actual /proc filesystem
23  * tree) of these proc_dir_entries, so that we can dynamically
24  * add new files to /proc.
25  *
26  * parent/subdir are used for the directory structure (every /proc file has a
27  * parent, but "subdir" is empty for all non-directory entries).
28  * subdir_node is used to build the rb tree "subdir" of the parent.
29  */
30 struct proc_dir_entry {
31 	/*
32 	 * number of callers into module in progress;
33 	 * negative -> it's going away RSN
34 	 */
35 	atomic_t in_use;
36 	refcount_t refcnt;
37 	struct list_head pde_openers;	/* who did ->open, but not ->release */
38 	/* protects ->pde_openers and all struct pde_opener instances */
39 	spinlock_t pde_unload_lock;
40 	struct completion *pde_unload_completion;
41 	const struct inode_operations *proc_iops;
42 	const struct file_operations *proc_fops;
43 	const struct dentry_operations *proc_dops;
44 	union {
45 		const struct seq_operations *seq_ops;
46 		int (*single_show)(struct seq_file *, void *);
47 	};
48 	proc_write_t write;
49 	void *data;
50 	unsigned int state_size;
51 	unsigned int low_ino;
52 	nlink_t nlink;
53 	kuid_t uid;
54 	kgid_t gid;
55 	loff_t size;
56 	struct proc_dir_entry *parent;
57 	struct rb_root subdir;
58 	struct rb_node subdir_node;
59 	char *name;
60 	umode_t mode;
61 	u8 namelen;
62 	char inline_name[];
63 } __randomize_layout;
64 
65 #define SIZEOF_PDE	(				\
66 	sizeof(struct proc_dir_entry) < 128 ? 128 :	\
67 	sizeof(struct proc_dir_entry) < 192 ? 192 :	\
68 	sizeof(struct proc_dir_entry) < 256 ? 256 :	\
69 	sizeof(struct proc_dir_entry) < 512 ? 512 :	\
70 	0)
71 #define SIZEOF_PDE_INLINE_NAME (SIZEOF_PDE - sizeof(struct proc_dir_entry))
72 
73 extern struct kmem_cache *proc_dir_entry_cache;
74 void pde_free(struct proc_dir_entry *pde);
75 
76 union proc_op {
77 	int (*proc_get_link)(struct dentry *, struct path *);
78 	int (*proc_show)(struct seq_file *m,
79 		struct pid_namespace *ns, struct pid *pid,
80 		struct task_struct *task);
81 	const char *lsm;
82 };
83 
84 struct proc_inode {
85 	struct pid *pid;
86 	unsigned int fd;
87 	union proc_op op;
88 	struct proc_dir_entry *pde;
89 	struct ctl_table_header *sysctl;
90 	struct ctl_table *sysctl_entry;
91 	struct hlist_node sysctl_inodes;
92 	const struct proc_ns_operations *ns_ops;
93 	struct inode vfs_inode;
94 } __randomize_layout;
95 
96 /*
97  * General functions
98  */
99 static inline struct proc_inode *PROC_I(const struct inode *inode)
100 {
101 	return container_of(inode, struct proc_inode, vfs_inode);
102 }
103 
104 static inline struct proc_dir_entry *PDE(const struct inode *inode)
105 {
106 	return PROC_I(inode)->pde;
107 }
108 
109 static inline void *__PDE_DATA(const struct inode *inode)
110 {
111 	return PDE(inode)->data;
112 }
113 
114 static inline struct pid *proc_pid(const struct inode *inode)
115 {
116 	return PROC_I(inode)->pid;
117 }
118 
119 static inline struct task_struct *get_proc_task(const struct inode *inode)
120 {
121 	return get_pid_task(proc_pid(inode), PIDTYPE_PID);
122 }
123 
124 void task_dump_owner(struct task_struct *task, umode_t mode,
125 		     kuid_t *ruid, kgid_t *rgid);
126 
127 unsigned name_to_int(const struct qstr *qstr);
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 void proc_task_name(struct seq_file *m, struct task_struct *p,
142 			   bool escape);
143 extern int proc_tid_stat(struct seq_file *, struct pid_namespace *,
144 			 struct pid *, struct task_struct *);
145 extern int proc_tgid_stat(struct seq_file *, struct pid_namespace *,
146 			  struct pid *, struct task_struct *);
147 extern int proc_pid_status(struct seq_file *, struct pid_namespace *,
148 			   struct pid *, struct task_struct *);
149 extern int proc_pid_statm(struct seq_file *, struct pid_namespace *,
150 			  struct pid *, struct task_struct *);
151 
152 /*
153  * base.c
154  */
155 extern const struct dentry_operations pid_dentry_operations;
156 extern int pid_getattr(const struct path *, struct kstat *, u32, unsigned int);
157 extern int proc_setattr(struct dentry *, struct iattr *);
158 extern struct inode *proc_pid_make_inode(struct super_block *, struct task_struct *, umode_t);
159 extern void pid_update_inode(struct task_struct *, struct inode *);
160 extern int pid_delete_dentry(const struct dentry *);
161 extern int proc_pid_readdir(struct file *, struct dir_context *);
162 struct dentry *proc_pid_lookup(struct dentry *, unsigned int);
163 extern loff_t mem_lseek(struct file *, loff_t, int);
164 
165 /* Lookups */
166 typedef struct dentry *instantiate_t(struct dentry *,
167 				     struct task_struct *, const void *);
168 bool proc_fill_cache(struct file *, struct dir_context *, const char *, unsigned int,
169 			   instantiate_t, struct task_struct *, const void *);
170 
171 /*
172  * generic.c
173  */
174 struct proc_dir_entry *proc_create_reg(const char *name, umode_t mode,
175 		struct proc_dir_entry **parent, void *data);
176 struct proc_dir_entry *proc_register(struct proc_dir_entry *dir,
177 		struct proc_dir_entry *dp);
178 extern struct dentry *proc_lookup(struct inode *, struct dentry *, unsigned int);
179 struct dentry *proc_lookup_de(struct inode *, struct dentry *, struct proc_dir_entry *);
180 extern int proc_readdir(struct file *, struct dir_context *);
181 int proc_readdir_de(struct file *, struct dir_context *, struct proc_dir_entry *);
182 
183 static inline struct proc_dir_entry *pde_get(struct proc_dir_entry *pde)
184 {
185 	refcount_inc(&pde->refcnt);
186 	return pde;
187 }
188 extern void pde_put(struct proc_dir_entry *);
189 
190 static inline bool is_empty_pde(const struct proc_dir_entry *pde)
191 {
192 	return S_ISDIR(pde->mode) && !pde->proc_iops;
193 }
194 extern ssize_t proc_simple_write(struct file *, const char __user *, size_t, loff_t *);
195 
196 /*
197  * inode.c
198  */
199 struct pde_opener {
200 	struct file *file;
201 	struct list_head lh;
202 	bool closing;
203 	struct completion *c;
204 } __randomize_layout;
205 extern const struct inode_operations proc_link_inode_operations;
206 extern const struct inode_operations proc_pid_link_inode_operations;
207 extern const struct super_operations proc_sops;
208 
209 void proc_init_kmemcache(void);
210 void set_proc_pid_nlink(void);
211 extern struct inode *proc_get_inode(struct super_block *, struct proc_dir_entry *);
212 extern void proc_entry_rundown(struct proc_dir_entry *);
213 
214 /*
215  * proc_namespaces.c
216  */
217 extern const struct inode_operations proc_ns_dir_inode_operations;
218 extern const struct file_operations proc_ns_dir_operations;
219 
220 /*
221  * proc_net.c
222  */
223 extern const struct file_operations proc_net_operations;
224 extern const struct inode_operations proc_net_inode_operations;
225 
226 #ifdef CONFIG_NET
227 extern int proc_net_init(void);
228 #else
229 static inline int proc_net_init(void) { return 0; }
230 #endif
231 
232 /*
233  * proc_self.c
234  */
235 extern int proc_setup_self(struct super_block *);
236 
237 /*
238  * proc_thread_self.c
239  */
240 extern int proc_setup_thread_self(struct super_block *);
241 extern void proc_thread_self_init(void);
242 
243 /*
244  * proc_sysctl.c
245  */
246 #ifdef CONFIG_PROC_SYSCTL
247 extern int proc_sys_init(void);
248 extern void proc_sys_evict_inode(struct inode *inode,
249 				 struct ctl_table_header *head);
250 #else
251 static inline void proc_sys_init(void) { }
252 static inline void proc_sys_evict_inode(struct  inode *inode,
253 					struct ctl_table_header *head) { }
254 #endif
255 
256 /*
257  * proc_tty.c
258  */
259 #ifdef CONFIG_TTY
260 extern void proc_tty_init(void);
261 #else
262 static inline void proc_tty_init(void) {}
263 #endif
264 
265 /*
266  * root.c
267  */
268 extern struct proc_dir_entry proc_root;
269 
270 extern void proc_self_init(void);
271 
272 /*
273  * task_[no]mmu.c
274  */
275 struct mem_size_stats;
276 struct proc_maps_private {
277 	struct inode *inode;
278 	struct task_struct *task;
279 	struct mm_struct *mm;
280 #ifdef CONFIG_MMU
281 	struct vm_area_struct *tail_vma;
282 #endif
283 #ifdef CONFIG_NUMA
284 	struct mempolicy *task_mempolicy;
285 #endif
286 } __randomize_layout;
287 
288 struct mm_struct *proc_mem_open(struct inode *inode, unsigned int mode);
289 
290 extern const struct file_operations proc_pid_maps_operations;
291 extern const struct file_operations proc_pid_numa_maps_operations;
292 extern const struct file_operations proc_pid_smaps_operations;
293 extern const struct file_operations proc_pid_smaps_rollup_operations;
294 extern const struct file_operations proc_clear_refs_operations;
295 extern const struct file_operations proc_pagemap_operations;
296 
297 extern unsigned long task_vsize(struct mm_struct *);
298 extern unsigned long task_statm(struct mm_struct *,
299 				unsigned long *, unsigned long *,
300 				unsigned long *, unsigned long *);
301 extern void task_mem(struct seq_file *, struct mm_struct *);
302