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 union {
43 const struct proc_ops *proc_ops;
44 const struct file_operations *proc_dir_ops;
45 };
46 const struct dentry_operations *proc_dops;
47 union {
48 const struct seq_operations *seq_ops;
49 int (*single_show)(struct seq_file *, void *);
50 };
51 proc_write_t write;
52 void *data;
53 unsigned int state_size;
54 unsigned int low_ino;
55 nlink_t nlink;
56 kuid_t uid;
57 kgid_t gid;
58 loff_t size;
59 struct proc_dir_entry *parent;
60 struct rb_root subdir;
61 struct rb_node subdir_node;
62 char *name;
63 umode_t mode;
64 u8 flags;
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
pde_is_permanent(const struct proc_dir_entry * pde)77 static inline bool pde_is_permanent(const struct proc_dir_entry *pde)
78 {
79 return pde->flags & PROC_ENTRY_PERMANENT;
80 }
81
pde_make_permanent(struct proc_dir_entry * pde)82 static inline void pde_make_permanent(struct proc_dir_entry *pde)
83 {
84 pde->flags |= PROC_ENTRY_PERMANENT;
85 }
86
87 extern struct kmem_cache *proc_dir_entry_cache;
88 void pde_free(struct proc_dir_entry *pde);
89
90 union proc_op {
91 int (*proc_get_link)(struct dentry *, struct path *);
92 int (*proc_show)(struct seq_file *m,
93 struct pid_namespace *ns, struct pid *pid,
94 struct task_struct *task);
95 const char *lsm;
96 };
97
98 struct proc_inode {
99 struct pid *pid;
100 unsigned int fd;
101 union proc_op op;
102 struct proc_dir_entry *pde;
103 struct ctl_table_header *sysctl;
104 struct ctl_table *sysctl_entry;
105 struct hlist_node sibling_inodes;
106 const struct proc_ns_operations *ns_ops;
107 struct inode vfs_inode;
108 } __randomize_layout;
109
110 /*
111 * General functions
112 */
PROC_I(const struct inode * inode)113 static inline struct proc_inode *PROC_I(const struct inode *inode)
114 {
115 return container_of(inode, struct proc_inode, vfs_inode);
116 }
117
PDE(const struct inode * inode)118 static inline struct proc_dir_entry *PDE(const struct inode *inode)
119 {
120 return PROC_I(inode)->pde;
121 }
122
proc_pid(const struct inode * inode)123 static inline struct pid *proc_pid(const struct inode *inode)
124 {
125 return PROC_I(inode)->pid;
126 }
127
get_proc_task(const struct inode * inode)128 static inline struct task_struct *get_proc_task(const struct inode *inode)
129 {
130 return get_pid_task(proc_pid(inode), PIDTYPE_PID);
131 }
132
133 void task_dump_owner(struct task_struct *task, umode_t mode,
134 kuid_t *ruid, kgid_t *rgid);
135
136 unsigned name_to_int(const struct qstr *qstr);
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 void proc_task_name(struct seq_file *m, struct task_struct *p,
151 bool escape);
152 extern int proc_tid_stat(struct seq_file *, struct pid_namespace *,
153 struct pid *, struct task_struct *);
154 extern int proc_tgid_stat(struct seq_file *, struct pid_namespace *,
155 struct pid *, struct task_struct *);
156 extern int proc_pid_status(struct seq_file *, struct pid_namespace *,
157 struct pid *, struct task_struct *);
158 extern int proc_pid_statm(struct seq_file *, struct pid_namespace *,
159 struct pid *, struct task_struct *);
160
161 /*
162 * base.c
163 */
164 extern const struct dentry_operations pid_dentry_operations;
165 extern int pid_getattr(struct user_namespace *, const struct path *,
166 struct kstat *, u32, unsigned int);
167 extern int proc_setattr(struct user_namespace *, struct dentry *,
168 struct iattr *);
169 extern void proc_pid_evict_inode(struct proc_inode *);
170 extern struct inode *proc_pid_make_inode(struct super_block *, struct task_struct *, umode_t);
171 extern void pid_update_inode(struct task_struct *, struct inode *);
172 extern int pid_delete_dentry(const struct dentry *);
173 extern int proc_pid_readdir(struct file *, struct dir_context *);
174 struct dentry *proc_pid_lookup(struct dentry *, unsigned int);
175 extern loff_t mem_lseek(struct file *, loff_t, int);
176
177 /* Lookups */
178 typedef struct dentry *instantiate_t(struct dentry *,
179 struct task_struct *, const void *);
180 bool proc_fill_cache(struct file *, struct dir_context *, const char *, unsigned int,
181 instantiate_t, struct task_struct *, const void *);
182
183 /*
184 * generic.c
185 */
186 struct proc_dir_entry *proc_create_reg(const char *name, umode_t mode,
187 struct proc_dir_entry **parent, void *data);
188 struct proc_dir_entry *proc_register(struct proc_dir_entry *dir,
189 struct proc_dir_entry *dp);
190 extern struct dentry *proc_lookup(struct inode *, struct dentry *, unsigned int);
191 struct dentry *proc_lookup_de(struct inode *, struct dentry *, struct proc_dir_entry *);
192 extern int proc_readdir(struct file *, struct dir_context *);
193 int proc_readdir_de(struct file *, struct dir_context *, struct proc_dir_entry *);
194
pde_get(struct proc_dir_entry * pde)195 static inline void pde_get(struct proc_dir_entry *pde)
196 {
197 refcount_inc(&pde->refcnt);
198 }
199 extern void pde_put(struct proc_dir_entry *);
200
is_empty_pde(const struct proc_dir_entry * pde)201 static inline bool is_empty_pde(const struct proc_dir_entry *pde)
202 {
203 return S_ISDIR(pde->mode) && !pde->proc_iops;
204 }
205 extern ssize_t proc_simple_write(struct file *, const char __user *, size_t, loff_t *);
206
207 /*
208 * inode.c
209 */
210 struct pde_opener {
211 struct list_head lh;
212 struct file *file;
213 bool closing;
214 struct completion *c;
215 } __randomize_layout;
216 extern const struct inode_operations proc_link_inode_operations;
217 extern const struct inode_operations proc_pid_link_inode_operations;
218 extern const struct super_operations proc_sops;
219
220 void proc_init_kmemcache(void);
221 void proc_invalidate_siblings_dcache(struct hlist_head *inodes, spinlock_t *lock);
222 void set_proc_pid_nlink(void);
223 extern struct inode *proc_get_inode(struct super_block *, struct proc_dir_entry *);
224 extern void proc_entry_rundown(struct proc_dir_entry *);
225
226 /*
227 * proc_namespaces.c
228 */
229 extern const struct inode_operations proc_ns_dir_inode_operations;
230 extern const struct file_operations proc_ns_dir_operations;
231
232 /*
233 * proc_net.c
234 */
235 extern const struct file_operations proc_net_operations;
236 extern const struct inode_operations proc_net_inode_operations;
237
238 #ifdef CONFIG_NET
239 extern int proc_net_init(void);
240 #else
proc_net_init(void)241 static inline int proc_net_init(void) { return 0; }
242 #endif
243
244 /*
245 * proc_self.c
246 */
247 extern int proc_setup_self(struct super_block *);
248
249 /*
250 * proc_thread_self.c
251 */
252 extern int proc_setup_thread_self(struct super_block *);
253 extern void proc_thread_self_init(void);
254
255 /*
256 * proc_sysctl.c
257 */
258 #ifdef CONFIG_PROC_SYSCTL
259 extern int proc_sys_init(void);
260 extern void proc_sys_evict_inode(struct inode *inode,
261 struct ctl_table_header *head);
262 #else
proc_sys_init(void)263 static inline void proc_sys_init(void) { }
proc_sys_evict_inode(struct inode * inode,struct ctl_table_header * head)264 static inline void proc_sys_evict_inode(struct inode *inode,
265 struct ctl_table_header *head) { }
266 #endif
267
268 /*
269 * proc_tty.c
270 */
271 #ifdef CONFIG_TTY
272 extern void proc_tty_init(void);
273 #else
proc_tty_init(void)274 static inline void proc_tty_init(void) {}
275 #endif
276
277 /*
278 * root.c
279 */
280 extern struct proc_dir_entry proc_root;
281
282 extern void proc_self_init(void);
283
284 /*
285 * task_[no]mmu.c
286 */
287 struct mem_size_stats;
288 struct proc_maps_private {
289 struct inode *inode;
290 struct task_struct *task;
291 struct mm_struct *mm;
292 #ifdef CONFIG_MMU
293 struct vma_iterator iter;
294 #endif
295 #ifdef CONFIG_NUMA
296 struct mempolicy *task_mempolicy;
297 #endif
298 } __randomize_layout;
299
300 struct mm_struct *proc_mem_open(struct inode *inode, unsigned int mode);
301
302 extern const struct file_operations proc_pid_maps_operations;
303 extern const struct file_operations proc_pid_numa_maps_operations;
304 extern const struct file_operations proc_pid_smaps_operations;
305 extern const struct file_operations proc_pid_smaps_rollup_operations;
306 extern const struct file_operations proc_clear_refs_operations;
307 extern const struct file_operations proc_pagemap_operations;
308
309 extern unsigned long task_vsize(struct mm_struct *);
310 extern unsigned long task_statm(struct mm_struct *,
311 unsigned long *, unsigned long *,
312 unsigned long *, unsigned long *);
313 extern void task_mem(struct seq_file *, struct mm_struct *);
314
315 extern const struct dentry_operations proc_net_dentry_ops;
pde_force_lookup(struct proc_dir_entry * pde)316 static inline void pde_force_lookup(struct proc_dir_entry *pde)
317 {
318 /* /proc/net/ entries can be changed under us by setns(CLONE_NEWNET) */
319 pde->proc_dops = &proc_net_dentry_ops;
320 }
321