xref: /openbmc/linux/fs/proc/internal.h (revision 31eeb6b0)
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  
77  static inline bool pde_is_permanent(const struct proc_dir_entry *pde)
78  {
79  	return pde->flags & PROC_ENTRY_PERMANENT;
80  }
81  
82  extern struct kmem_cache *proc_dir_entry_cache;
83  void pde_free(struct proc_dir_entry *pde);
84  
85  union proc_op {
86  	int (*proc_get_link)(struct dentry *, struct path *);
87  	int (*proc_show)(struct seq_file *m,
88  		struct pid_namespace *ns, struct pid *pid,
89  		struct task_struct *task);
90  	const char *lsm;
91  };
92  
93  struct proc_inode {
94  	struct pid *pid;
95  	unsigned int fd;
96  	union proc_op op;
97  	struct proc_dir_entry *pde;
98  	struct ctl_table_header *sysctl;
99  	struct ctl_table *sysctl_entry;
100  	struct hlist_node sibling_inodes;
101  	const struct proc_ns_operations *ns_ops;
102  	struct inode vfs_inode;
103  } __randomize_layout;
104  
105  /*
106   * General functions
107   */
108  static inline struct proc_inode *PROC_I(const struct inode *inode)
109  {
110  	return container_of(inode, struct proc_inode, vfs_inode);
111  }
112  
113  static inline struct proc_dir_entry *PDE(const struct inode *inode)
114  {
115  	return PROC_I(inode)->pde;
116  }
117  
118  static inline struct pid *proc_pid(const struct inode *inode)
119  {
120  	return PROC_I(inode)->pid;
121  }
122  
123  static inline struct task_struct *get_proc_task(const struct inode *inode)
124  {
125  	return get_pid_task(proc_pid(inode), PIDTYPE_PID);
126  }
127  
128  void task_dump_owner(struct task_struct *task, umode_t mode,
129  		     kuid_t *ruid, kgid_t *rgid);
130  
131  unsigned name_to_int(const struct qstr *qstr);
132  /*
133   * Offset of the first process in the /proc root directory..
134   */
135  #define FIRST_PROCESS_ENTRY 256
136  
137  /* Worst case buffer size needed for holding an integer. */
138  #define PROC_NUMBUF 13
139  
140  /*
141   * array.c
142   */
143  extern const struct file_operations proc_tid_children_operations;
144  
145  extern void proc_task_name(struct seq_file *m, struct task_struct *p,
146  			   bool escape);
147  extern int proc_tid_stat(struct seq_file *, struct pid_namespace *,
148  			 struct pid *, struct task_struct *);
149  extern int proc_tgid_stat(struct seq_file *, struct pid_namespace *,
150  			  struct pid *, struct task_struct *);
151  extern int proc_pid_status(struct seq_file *, struct pid_namespace *,
152  			   struct pid *, struct task_struct *);
153  extern int proc_pid_statm(struct seq_file *, struct pid_namespace *,
154  			  struct pid *, struct task_struct *);
155  
156  /*
157   * base.c
158   */
159  extern const struct dentry_operations pid_dentry_operations;
160  extern int pid_getattr(struct user_namespace *, const struct path *,
161  		       struct kstat *, u32, unsigned int);
162  extern int proc_setattr(struct user_namespace *, struct dentry *,
163  			struct iattr *);
164  extern void proc_pid_evict_inode(struct proc_inode *);
165  extern struct inode *proc_pid_make_inode(struct super_block *, struct task_struct *, umode_t);
166  extern void pid_update_inode(struct task_struct *, struct inode *);
167  extern int pid_delete_dentry(const struct dentry *);
168  extern int proc_pid_readdir(struct file *, struct dir_context *);
169  struct dentry *proc_pid_lookup(struct dentry *, unsigned int);
170  extern loff_t mem_lseek(struct file *, loff_t, int);
171  
172  /* Lookups */
173  typedef struct dentry *instantiate_t(struct dentry *,
174  				     struct task_struct *, const void *);
175  bool proc_fill_cache(struct file *, struct dir_context *, const char *, unsigned int,
176  			   instantiate_t, struct task_struct *, const void *);
177  
178  /*
179   * generic.c
180   */
181  struct proc_dir_entry *proc_create_reg(const char *name, umode_t mode,
182  		struct proc_dir_entry **parent, void *data);
183  struct proc_dir_entry *proc_register(struct proc_dir_entry *dir,
184  		struct proc_dir_entry *dp);
185  extern struct dentry *proc_lookup(struct inode *, struct dentry *, unsigned int);
186  struct dentry *proc_lookup_de(struct inode *, struct dentry *, struct proc_dir_entry *);
187  extern int proc_readdir(struct file *, struct dir_context *);
188  int proc_readdir_de(struct file *, struct dir_context *, struct proc_dir_entry *);
189  
190  static inline void pde_get(struct proc_dir_entry *pde)
191  {
192  	refcount_inc(&pde->refcnt);
193  }
194  extern void pde_put(struct proc_dir_entry *);
195  
196  static inline bool is_empty_pde(const struct proc_dir_entry *pde)
197  {
198  	return S_ISDIR(pde->mode) && !pde->proc_iops;
199  }
200  extern ssize_t proc_simple_write(struct file *, const char __user *, size_t, loff_t *);
201  
202  /*
203   * inode.c
204   */
205  struct pde_opener {
206  	struct list_head lh;
207  	struct file *file;
208  	bool closing;
209  	struct completion *c;
210  } __randomize_layout;
211  extern const struct inode_operations proc_link_inode_operations;
212  extern const struct inode_operations proc_pid_link_inode_operations;
213  extern const struct super_operations proc_sops;
214  
215  void proc_init_kmemcache(void);
216  void proc_invalidate_siblings_dcache(struct hlist_head *inodes, spinlock_t *lock);
217  void set_proc_pid_nlink(void);
218  extern struct inode *proc_get_inode(struct super_block *, struct proc_dir_entry *);
219  extern void proc_entry_rundown(struct proc_dir_entry *);
220  
221  /*
222   * proc_namespaces.c
223   */
224  extern const struct inode_operations proc_ns_dir_inode_operations;
225  extern const struct file_operations proc_ns_dir_operations;
226  
227  /*
228   * proc_net.c
229   */
230  extern const struct file_operations proc_net_operations;
231  extern const struct inode_operations proc_net_inode_operations;
232  
233  #ifdef CONFIG_NET
234  extern int proc_net_init(void);
235  #else
236  static inline int proc_net_init(void) { return 0; }
237  #endif
238  
239  /*
240   * proc_self.c
241   */
242  extern int proc_setup_self(struct super_block *);
243  
244  /*
245   * proc_thread_self.c
246   */
247  extern int proc_setup_thread_self(struct super_block *);
248  extern void proc_thread_self_init(void);
249  
250  /*
251   * proc_sysctl.c
252   */
253  #ifdef CONFIG_PROC_SYSCTL
254  extern int proc_sys_init(void);
255  extern void proc_sys_evict_inode(struct inode *inode,
256  				 struct ctl_table_header *head);
257  #else
258  static inline void proc_sys_init(void) { }
259  static inline void proc_sys_evict_inode(struct  inode *inode,
260  					struct ctl_table_header *head) { }
261  #endif
262  
263  /*
264   * proc_tty.c
265   */
266  #ifdef CONFIG_TTY
267  extern void proc_tty_init(void);
268  #else
269  static inline void proc_tty_init(void) {}
270  #endif
271  
272  /*
273   * root.c
274   */
275  extern struct proc_dir_entry proc_root;
276  
277  extern void proc_self_init(void);
278  
279  /*
280   * task_[no]mmu.c
281   */
282  struct mem_size_stats;
283  struct proc_maps_private {
284  	struct inode *inode;
285  	struct task_struct *task;
286  	struct mm_struct *mm;
287  #ifdef CONFIG_MMU
288  	struct vm_area_struct *tail_vma;
289  #endif
290  #ifdef CONFIG_NUMA
291  	struct mempolicy *task_mempolicy;
292  #endif
293  } __randomize_layout;
294  
295  struct mm_struct *proc_mem_open(struct inode *inode, unsigned int mode);
296  
297  extern const struct file_operations proc_pid_maps_operations;
298  extern const struct file_operations proc_pid_numa_maps_operations;
299  extern const struct file_operations proc_pid_smaps_operations;
300  extern const struct file_operations proc_pid_smaps_rollup_operations;
301  extern const struct file_operations proc_clear_refs_operations;
302  extern const struct file_operations proc_pagemap_operations;
303  
304  extern unsigned long task_vsize(struct mm_struct *);
305  extern unsigned long task_statm(struct mm_struct *,
306  				unsigned long *, unsigned long *,
307  				unsigned long *, unsigned long *);
308  extern void task_mem(struct seq_file *, struct mm_struct *);
309  
310  extern const struct dentry_operations proc_net_dentry_ops;
311  static inline void pde_force_lookup(struct proc_dir_entry *pde)
312  {
313  	/* /proc/net/ entries can be changed under us by setns(CLONE_NEWNET) */
314  	pde->proc_dops = &proc_net_dentry_ops;
315  }
316