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
pde_has_proc_read_iter(const struct proc_dir_entry * pde)87 static inline bool pde_has_proc_read_iter(const struct proc_dir_entry *pde)
88 {
89 return pde->flags & PROC_ENTRY_proc_read_iter;
90 }
91
pde_has_proc_compat_ioctl(const struct proc_dir_entry * pde)92 static inline bool pde_has_proc_compat_ioctl(const struct proc_dir_entry *pde)
93 {
94 #ifdef CONFIG_COMPAT
95 return pde->flags & PROC_ENTRY_proc_compat_ioctl;
96 #else
97 return false;
98 #endif
99 }
100
101 extern struct kmem_cache *proc_dir_entry_cache;
102 void pde_free(struct proc_dir_entry *pde);
103
104 union proc_op {
105 int (*proc_get_link)(struct dentry *, struct path *);
106 int (*proc_show)(struct seq_file *m,
107 struct pid_namespace *ns, struct pid *pid,
108 struct task_struct *task);
109 const char *lsm;
110 };
111
112 struct proc_inode {
113 struct pid *pid;
114 unsigned int fd;
115 union proc_op op;
116 struct proc_dir_entry *pde;
117 struct ctl_table_header *sysctl;
118 struct ctl_table *sysctl_entry;
119 struct hlist_node sibling_inodes;
120 const struct proc_ns_operations *ns_ops;
121 struct inode vfs_inode;
122 } __randomize_layout;
123
124 /*
125 * General functions
126 */
PROC_I(const struct inode * inode)127 static inline struct proc_inode *PROC_I(const struct inode *inode)
128 {
129 return container_of(inode, struct proc_inode, vfs_inode);
130 }
131
PDE(const struct inode * inode)132 static inline struct proc_dir_entry *PDE(const struct inode *inode)
133 {
134 return PROC_I(inode)->pde;
135 }
136
proc_pid(const struct inode * inode)137 static inline struct pid *proc_pid(const struct inode *inode)
138 {
139 return PROC_I(inode)->pid;
140 }
141
get_proc_task(const struct inode * inode)142 static inline struct task_struct *get_proc_task(const struct inode *inode)
143 {
144 return get_pid_task(proc_pid(inode), PIDTYPE_PID);
145 }
146
147 void task_dump_owner(struct task_struct *task, umode_t mode,
148 kuid_t *ruid, kgid_t *rgid);
149
150 unsigned name_to_int(const struct qstr *qstr);
151 /*
152 * Offset of the first process in the /proc root directory..
153 */
154 #define FIRST_PROCESS_ENTRY 256
155
156 /* Worst case buffer size needed for holding an integer. */
157 #define PROC_NUMBUF 13
158
159 /*
160 * array.c
161 */
162 extern const struct file_operations proc_tid_children_operations;
163
164 extern void proc_task_name(struct seq_file *m, struct task_struct *p,
165 bool escape);
166 extern int proc_tid_stat(struct seq_file *, struct pid_namespace *,
167 struct pid *, struct task_struct *);
168 extern int proc_tgid_stat(struct seq_file *, struct pid_namespace *,
169 struct pid *, struct task_struct *);
170 extern int proc_pid_status(struct seq_file *, struct pid_namespace *,
171 struct pid *, struct task_struct *);
172 extern int proc_pid_statm(struct seq_file *, struct pid_namespace *,
173 struct pid *, struct task_struct *);
174
175 /*
176 * base.c
177 */
178 extern const struct dentry_operations pid_dentry_operations;
179 extern int pid_getattr(struct mnt_idmap *, const struct path *,
180 struct kstat *, u32, unsigned int);
181 extern int proc_setattr(struct mnt_idmap *, struct dentry *,
182 struct iattr *);
183 extern void proc_pid_evict_inode(struct proc_inode *);
184 extern struct inode *proc_pid_make_inode(struct super_block *, struct task_struct *, umode_t);
185 extern void pid_update_inode(struct task_struct *, struct inode *);
186 extern int pid_delete_dentry(const struct dentry *);
187 extern int proc_pid_readdir(struct file *, struct dir_context *);
188 struct dentry *proc_pid_lookup(struct dentry *, unsigned int);
189 extern loff_t mem_lseek(struct file *, loff_t, int);
190
191 /* Lookups */
192 typedef struct dentry *instantiate_t(struct dentry *,
193 struct task_struct *, const void *);
194 bool proc_fill_cache(struct file *, struct dir_context *, const char *, unsigned int,
195 instantiate_t, struct task_struct *, const void *);
196
197 /*
198 * generic.c
199 */
200 struct proc_dir_entry *proc_create_reg(const char *name, umode_t mode,
201 struct proc_dir_entry **parent, void *data);
202 struct proc_dir_entry *proc_register(struct proc_dir_entry *dir,
203 struct proc_dir_entry *dp);
204 extern struct dentry *proc_lookup(struct inode *, struct dentry *, unsigned int);
205 struct dentry *proc_lookup_de(struct inode *, struct dentry *, struct proc_dir_entry *);
206 extern int proc_readdir(struct file *, struct dir_context *);
207 int proc_readdir_de(struct file *, struct dir_context *, struct proc_dir_entry *);
208
pde_get(struct proc_dir_entry * pde)209 static inline void pde_get(struct proc_dir_entry *pde)
210 {
211 refcount_inc(&pde->refcnt);
212 }
213 extern void pde_put(struct proc_dir_entry *);
214
is_empty_pde(const struct proc_dir_entry * pde)215 static inline bool is_empty_pde(const struct proc_dir_entry *pde)
216 {
217 return S_ISDIR(pde->mode) && !pde->proc_iops;
218 }
219 extern ssize_t proc_simple_write(struct file *, const char __user *, size_t, loff_t *);
220
221 /*
222 * inode.c
223 */
224 struct pde_opener {
225 struct list_head lh;
226 struct file *file;
227 bool closing;
228 struct completion *c;
229 } __randomize_layout;
230 extern const struct inode_operations proc_link_inode_operations;
231 extern const struct inode_operations proc_pid_link_inode_operations;
232 extern const struct super_operations proc_sops;
233
234 void proc_init_kmemcache(void);
235 void proc_invalidate_siblings_dcache(struct hlist_head *inodes, spinlock_t *lock);
236 void set_proc_pid_nlink(void);
237 extern struct inode *proc_get_inode(struct super_block *, struct proc_dir_entry *);
238 extern void proc_entry_rundown(struct proc_dir_entry *);
239
240 /*
241 * proc_namespaces.c
242 */
243 extern const struct inode_operations proc_ns_dir_inode_operations;
244 extern const struct file_operations proc_ns_dir_operations;
245
246 /*
247 * proc_net.c
248 */
249 extern const struct file_operations proc_net_operations;
250 extern const struct inode_operations proc_net_inode_operations;
251
252 #ifdef CONFIG_NET
253 extern int proc_net_init(void);
254 #else
proc_net_init(void)255 static inline int proc_net_init(void) { return 0; }
256 #endif
257
258 /*
259 * proc_self.c
260 */
261 extern int proc_setup_self(struct super_block *);
262
263 /*
264 * proc_thread_self.c
265 */
266 extern int proc_setup_thread_self(struct super_block *);
267 extern void proc_thread_self_init(void);
268
269 /*
270 * proc_sysctl.c
271 */
272 #ifdef CONFIG_PROC_SYSCTL
273 extern int proc_sys_init(void);
274 extern void proc_sys_evict_inode(struct inode *inode,
275 struct ctl_table_header *head);
276 #else
proc_sys_init(void)277 static inline void proc_sys_init(void) { }
proc_sys_evict_inode(struct inode * inode,struct ctl_table_header * head)278 static inline void proc_sys_evict_inode(struct inode *inode,
279 struct ctl_table_header *head) { }
280 #endif
281
282 /*
283 * proc_tty.c
284 */
285 #ifdef CONFIG_TTY
286 extern void proc_tty_init(void);
287 #else
proc_tty_init(void)288 static inline void proc_tty_init(void) {}
289 #endif
290
291 /*
292 * root.c
293 */
294 extern struct proc_dir_entry proc_root;
295
296 extern void proc_self_init(void);
297
298 /*
299 * task_[no]mmu.c
300 */
301 struct mem_size_stats;
302 struct proc_maps_private {
303 struct inode *inode;
304 struct task_struct *task;
305 struct mm_struct *mm;
306 struct vma_iterator iter;
307 #ifdef CONFIG_NUMA
308 struct mempolicy *task_mempolicy;
309 #endif
310 } __randomize_layout;
311
312 struct mm_struct *proc_mem_open(struct inode *inode, unsigned int mode);
313
314 extern const struct file_operations proc_pid_maps_operations;
315 extern const struct file_operations proc_pid_numa_maps_operations;
316 extern const struct file_operations proc_pid_smaps_operations;
317 extern const struct file_operations proc_pid_smaps_rollup_operations;
318 extern const struct file_operations proc_clear_refs_operations;
319 extern const struct file_operations proc_pagemap_operations;
320
321 extern unsigned long task_vsize(struct mm_struct *);
322 extern unsigned long task_statm(struct mm_struct *,
323 unsigned long *, unsigned long *,
324 unsigned long *, unsigned long *);
325 extern void task_mem(struct seq_file *, struct mm_struct *);
326
327 extern const struct dentry_operations proc_net_dentry_ops;
pde_force_lookup(struct proc_dir_entry * pde)328 static inline void pde_force_lookup(struct proc_dir_entry *pde)
329 {
330 /* /proc/net/ entries can be changed under us by setns(CLONE_NEWNET) */
331 pde->proc_dops = &proc_net_dentry_ops;
332 }
333