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_has_proc_read_iter(const struct proc_dir_entry * pde)82 static inline bool pde_has_proc_read_iter(const struct proc_dir_entry *pde)
83 {
84 return pde->flags & PROC_ENTRY_proc_read_iter;
85 }
86
pde_has_proc_compat_ioctl(const struct proc_dir_entry * pde)87 static inline bool pde_has_proc_compat_ioctl(const struct proc_dir_entry *pde)
88 {
89 #ifdef CONFIG_COMPAT
90 return pde->flags & PROC_ENTRY_proc_compat_ioctl;
91 #else
92 return false;
93 #endif
94 }
95
96 extern struct kmem_cache *proc_dir_entry_cache;
97 void pde_free(struct proc_dir_entry *pde);
98
99 union proc_op {
100 int (*proc_get_link)(struct dentry *, struct path *);
101 int (*proc_show)(struct seq_file *m,
102 struct pid_namespace *ns, struct pid *pid,
103 struct task_struct *task);
104 const char *lsm;
105 };
106
107 struct proc_inode {
108 struct pid *pid;
109 unsigned int fd;
110 union proc_op op;
111 struct proc_dir_entry *pde;
112 struct ctl_table_header *sysctl;
113 struct ctl_table *sysctl_entry;
114 struct hlist_node sibling_inodes;
115 const struct proc_ns_operations *ns_ops;
116 struct inode vfs_inode;
117 } __randomize_layout;
118
119 /*
120 * General functions
121 */
PROC_I(const struct inode * inode)122 static inline struct proc_inode *PROC_I(const struct inode *inode)
123 {
124 return container_of(inode, struct proc_inode, vfs_inode);
125 }
126
PDE(const struct inode * inode)127 static inline struct proc_dir_entry *PDE(const struct inode *inode)
128 {
129 return PROC_I(inode)->pde;
130 }
131
__PDE_DATA(const struct inode * inode)132 static inline void *__PDE_DATA(const struct inode *inode)
133 {
134 return PDE(inode)->data;
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(const struct path *, struct kstat *, u32, unsigned int);
180 extern int proc_setattr(struct dentry *, struct iattr *);
181 extern void proc_pid_evict_inode(struct proc_inode *);
182 extern struct inode *proc_pid_make_inode(struct super_block *, struct task_struct *, umode_t);
183 extern void pid_update_inode(struct task_struct *, struct inode *);
184 extern int pid_delete_dentry(const struct dentry *);
185 extern int proc_pid_readdir(struct file *, struct dir_context *);
186 struct dentry *proc_pid_lookup(struct dentry *, unsigned int);
187 extern loff_t mem_lseek(struct file *, loff_t, int);
188 #ifdef CONFIG_RSS_THRESHOLD
189 extern int proc_pid_rss(struct seq_file *, struct pid_namespace *,
190 struct pid *, struct task_struct *);
191 extern void listen_rss_threshold(struct mm_struct *mm);
192 extern const struct file_operations proc_pid_rss_threshold_operations;
193 #endif
194
195 /* Lookups */
196 typedef struct dentry *instantiate_t(struct dentry *,
197 struct task_struct *, const void *);
198 bool proc_fill_cache(struct file *, struct dir_context *, const char *, unsigned int,
199 instantiate_t, struct task_struct *, const void *);
200
201 /*
202 * generic.c
203 */
204 struct proc_dir_entry *proc_create_reg(const char *name, umode_t mode,
205 struct proc_dir_entry **parent, void *data);
206 struct proc_dir_entry *proc_register(struct proc_dir_entry *dir,
207 struct proc_dir_entry *dp);
208 extern struct dentry *proc_lookup(struct inode *, struct dentry *, unsigned int);
209 struct dentry *proc_lookup_de(struct inode *, struct dentry *, struct proc_dir_entry *);
210 extern int proc_readdir(struct file *, struct dir_context *);
211 int proc_readdir_de(struct file *, struct dir_context *, struct proc_dir_entry *);
212
pde_get(struct proc_dir_entry * pde)213 static inline struct proc_dir_entry *pde_get(struct proc_dir_entry *pde)
214 {
215 refcount_inc(&pde->refcnt);
216 return pde;
217 }
218 extern void pde_put(struct proc_dir_entry *);
219
is_empty_pde(const struct proc_dir_entry * pde)220 static inline bool is_empty_pde(const struct proc_dir_entry *pde)
221 {
222 return S_ISDIR(pde->mode) && !pde->proc_iops;
223 }
224 extern ssize_t proc_simple_write(struct file *, const char __user *, size_t, loff_t *);
225
226 /*
227 * inode.c
228 */
229 struct pde_opener {
230 struct list_head lh;
231 struct file *file;
232 bool closing;
233 struct completion *c;
234 } __randomize_layout;
235 extern const struct inode_operations proc_link_inode_operations;
236 extern const struct inode_operations proc_pid_link_inode_operations;
237 extern const struct super_operations proc_sops;
238
239 void proc_init_kmemcache(void);
240 void proc_invalidate_siblings_dcache(struct hlist_head *inodes, spinlock_t *lock);
241 void set_proc_pid_nlink(void);
242 extern struct inode *proc_get_inode(struct super_block *, struct proc_dir_entry *);
243 extern void proc_entry_rundown(struct proc_dir_entry *);
244
245 /*
246 * proc_namespaces.c
247 */
248 extern const struct inode_operations proc_ns_dir_inode_operations;
249 extern const struct file_operations proc_ns_dir_operations;
250
251 /*
252 * proc_net.c
253 */
254 extern const struct file_operations proc_net_operations;
255 extern const struct inode_operations proc_net_inode_operations;
256
257 #ifdef CONFIG_NET
258 extern int proc_net_init(void);
259 #else
proc_net_init(void)260 static inline int proc_net_init(void) { return 0; }
261 #endif
262
263 /*
264 * proc_self.c
265 */
266 extern int proc_setup_self(struct super_block *);
267
268 /*
269 * proc_thread_self.c
270 */
271 extern int proc_setup_thread_self(struct super_block *);
272 extern void proc_thread_self_init(void);
273
274 /*
275 * proc_sysctl.c
276 */
277 #ifdef CONFIG_PROC_SYSCTL
278 extern int proc_sys_init(void);
279 extern void proc_sys_evict_inode(struct inode *inode,
280 struct ctl_table_header *head);
281 #else
proc_sys_init(void)282 static inline void proc_sys_init(void) { }
proc_sys_evict_inode(struct inode * inode,struct ctl_table_header * head)283 static inline void proc_sys_evict_inode(struct inode *inode,
284 struct ctl_table_header *head) { }
285 #endif
286
287 /*
288 * proc_tty.c
289 */
290 #ifdef CONFIG_TTY
291 extern void proc_tty_init(void);
292 #else
proc_tty_init(void)293 static inline void proc_tty_init(void) {}
294 #endif
295
296 /*
297 * root.c
298 */
299 extern struct proc_dir_entry proc_root;
300
301 extern void proc_self_init(void);
302
303 /*
304 * task_[no]mmu.c
305 */
306 struct mem_size_stats;
307 struct proc_maps_private {
308 struct inode *inode;
309 struct task_struct *task;
310 struct mm_struct *mm;
311 #ifdef CONFIG_MMU
312 struct vm_area_struct *tail_vma;
313 #endif
314 #ifdef CONFIG_NUMA
315 struct mempolicy *task_mempolicy;
316 #endif
317 } __randomize_layout;
318
319 struct mm_struct *proc_mem_open(struct inode *inode, unsigned int mode);
320
321 extern const struct file_operations proc_pid_maps_operations;
322 extern const struct file_operations proc_pid_numa_maps_operations;
323 extern const struct file_operations proc_pid_smaps_operations;
324 extern const struct file_operations proc_pid_smaps_rollup_operations;
325 extern const struct file_operations proc_clear_refs_operations;
326 extern const struct file_operations proc_pagemap_operations;
327 extern const struct file_operations proc_xpm_region_operations;
328
329 extern unsigned long task_vsize(struct mm_struct *);
330 extern unsigned long task_statm(struct mm_struct *,
331 unsigned long *, unsigned long *,
332 unsigned long *, unsigned long *);
333 extern void task_mem(struct seq_file *, struct mm_struct *);
334
335 extern const struct dentry_operations proc_net_dentry_ops;
pde_force_lookup(struct proc_dir_entry * pde)336 static inline void pde_force_lookup(struct proc_dir_entry *pde)
337 {
338 /* /proc/net/ entries can be changed under us by setns(CLONE_NEWNET) */
339 pde->proc_dops = &proc_net_dentry_ops;
340 }
341