fs/proc/internal.h

   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 namelen;
  65         char inline_name[];
  66 } __randomize_layout;
  67
  68 #define SIZEOF_PDE      (                               \
  69         sizeof(struct proc_dir_entry) < 128 ? 128 :     \
  70         sizeof(struct proc_dir_entry) < 192 ? 192 :     \
  71         sizeof(struct proc_dir_entry) < 256 ? 256 :     \
  72         sizeof(struct proc_dir_entry) < 512 ? 512 :     \
  73         0)
  74 #define SIZEOF_PDE_INLINE_NAME (SIZEOF_PDE - sizeof(struct proc_dir_entry))
  75
  76 extern struct kmem_cache *proc_dir_entry_cache;
  77 void pde_free(struct proc_dir_entry *pde);
  78
  79 union proc_op {
  80         int (*proc_get_link)(struct dentry *, struct path *);
  81         int (*proc_show)(struct seq_file *m,
  82                 struct pid_namespace *ns, struct pid *pid,
  83                 struct task_struct *task);
  84         const char *lsm;
  85 };
  86
  87 struct proc_inode {
  88         struct pid *pid;
  89         unsigned int fd;
  90         union proc_op op;
  91         struct proc_dir_entry *pde;
  92         struct ctl_table_header *sysctl;
  93         struct ctl_table *sysctl_entry;
  94         struct hlist_node sysctl_inodes;
  95         const struct proc_ns_operations *ns_ops;
  96         struct inode vfs_inode;
  97 } __randomize_layout;
  98
  99 /*
 100  * General functions
 101  */
 102 static inline struct proc_inode *PROC_I(const struct inode *inode)
 103 {
 104         return container_of(inode, struct proc_inode, vfs_inode);
 105 }
 106
 107 static inline struct proc_dir_entry *PDE(const struct inode *inode)
 108 {
 109         return PROC_I(inode)->pde;
 110 }
 111
 112 static inline void *__PDE_DATA(const struct inode *inode)
 113 {
 114         return PDE(inode)->data;
 115 }
 116
 117 static inline struct pid *proc_pid(const struct inode *inode)
 118 {
 119         return PROC_I(inode)->pid;
 120 }
 121
 122 static inline struct task_struct *get_proc_task(const struct inode *inode)
 123 {
 124         return get_pid_task(proc_pid(inode), PIDTYPE_PID);
 125 }
 126
 127 void task_dump_owner(struct task_struct *task, umode_t mode,
 128                      kuid_t *ruid, kgid_t *rgid);
 129
 130 unsigned name_to_int(const struct qstr *qstr);
 131 /*
 132  * Offset of the first process in the /proc root directory..
 133  */
 134 #define FIRST_PROCESS_ENTRY 256
 135
 136 /* Worst case buffer size needed for holding an integer. */
 137 #define PROC_NUMBUF 13
 138
 139 /*
 140  * array.c
 141  */
 142 extern const struct file_operations proc_tid_children_operations;
 143
 144 extern void proc_task_name(struct seq_file *m, struct task_struct *p,
 145                            bool escape);
 146 extern int proc_tid_stat(struct seq_file *, struct pid_namespace *,
 147                          struct pid *, struct task_struct *);
 148 extern int proc_tgid_stat(struct seq_file *, struct pid_namespace *,
 149                           struct pid *, struct task_struct *);
 150 extern int proc_pid_status(struct seq_file *, struct pid_namespace *,
 151                            struct pid *, struct task_struct *);
 152 extern int proc_pid_statm(struct seq_file *, struct pid_namespace *,
 153                           struct pid *, struct task_struct *);
 154
 155 /*
 156  * base.c
 157  */
 158 extern const struct dentry_operations pid_dentry_operations;
 159 extern int pid_getattr(const struct path *, struct kstat *, u32, unsigned int);
 160 extern int proc_setattr(struct dentry *, struct iattr *);
 161 extern struct inode *proc_pid_make_inode(struct super_block *, struct task_struct *, umode_t);
 162 extern void pid_update_inode(struct task_struct *, struct inode *);
 163 extern int pid_delete_dentry(const struct dentry *);
 164 extern int proc_pid_readdir(struct file *, struct dir_context *);
 165 struct dentry *proc_pid_lookup(struct dentry *, unsigned int);
 166 extern loff_t mem_lseek(struct file *, loff_t, int);
 167
 168 /* Lookups */
 169 typedef struct dentry *instantiate_t(struct dentry *,
 170                                      struct task_struct *, const void *);
 171 bool proc_fill_cache(struct file *, struct dir_context *, const char *, unsigned int,
 172                            instantiate_t, struct task_struct *, const void *);
 173
 174 /*
 175  * generic.c
 176  */
 177 struct proc_dir_entry *proc_create_reg(const char *name, umode_t mode,
 178                 struct proc_dir_entry **parent, void *data);
 179 struct proc_dir_entry *proc_register(struct proc_dir_entry *dir,
 180                 struct proc_dir_entry *dp);
 181 extern struct dentry *proc_lookup(struct inode *, struct dentry *, unsigned int);
 182 struct dentry *proc_lookup_de(struct inode *, struct dentry *, struct proc_dir_entry *);
 183 extern int proc_readdir(struct file *, struct dir_context *);
 184 int proc_readdir_de(struct file *, struct dir_context *, struct proc_dir_entry *);
 185
 186 static inline struct proc_dir_entry *pde_get(struct proc_dir_entry *pde)
 187 {
 188         refcount_inc(&pde->refcnt);
 189         return pde;
 190 }
 191 extern void pde_put(struct proc_dir_entry *);
 192
 193 static inline bool is_empty_pde(const struct proc_dir_entry *pde)
 194 {
 195         return S_ISDIR(pde->mode) && !pde->proc_iops;
 196 }
 197 extern ssize_t proc_simple_write(struct file *, const char __user *, size_t, loff_t *);
 198
 199 /*
 200  * inode.c
 201  */
 202 struct pde_opener {
 203         struct list_head lh;
 204         struct file *file;
 205         bool closing;
 206         struct completion *c;
 207 } __randomize_layout;
 208 extern const struct inode_operations proc_link_inode_operations;
 209 extern const struct inode_operations proc_pid_link_inode_operations;
 210 extern const struct super_operations proc_sops;
 211
 212 void proc_init_kmemcache(void);
 213 void set_proc_pid_nlink(void);
 214 extern struct inode *proc_get_inode(struct super_block *, struct proc_dir_entry *);
 215 extern void proc_entry_rundown(struct proc_dir_entry *);
 216
 217 /*
 218  * proc_namespaces.c
 219  */
 220 extern const struct inode_operations proc_ns_dir_inode_operations;
 221 extern const struct file_operations proc_ns_dir_operations;
 222
 223 /*
 224  * proc_net.c
 225  */
 226 extern const struct file_operations proc_net_operations;
 227 extern const struct inode_operations proc_net_inode_operations;
 228
 229 #ifdef CONFIG_NET
 230 extern int proc_net_init(void);
 231 #else
 232 static inline int proc_net_init(void) { return 0; }
 233 #endif
 234
 235 /*
 236  * proc_self.c
 237  */
 238 extern int proc_setup_self(struct super_block *);
 239
 240 /*
 241  * proc_thread_self.c
 242  */
 243 extern int proc_setup_thread_self(struct super_block *);
 244 extern void proc_thread_self_init(void);
 245
 246 /*
 247  * proc_sysctl.c
 248  */
 249 #ifdef CONFIG_PROC_SYSCTL
 250 extern int proc_sys_init(void);
 251 extern void proc_sys_evict_inode(struct inode *inode,
 252                                  struct ctl_table_header *head);
 253 #else
 254 static inline void proc_sys_init(void) { }
 255 static inline void proc_sys_evict_inode(struct  inode *inode,
 256                                         struct ctl_table_header *head) { }
 257 #endif
 258
 259 /*
 260  * proc_tty.c
 261  */
 262 #ifdef CONFIG_TTY
 263 extern void proc_tty_init(void);
 264 #else
 265 static inline void proc_tty_init(void) {}
 266 #endif
 267
 268 /*
 269  * root.c
 270  */
 271 extern struct proc_dir_entry proc_root;
 272
 273 extern void proc_self_init(void);
 274
 275 /*
 276  * task_[no]mmu.c
 277  */
 278 struct mem_size_stats;
 279 struct proc_maps_private {
 280         struct inode *inode;
 281         struct task_struct *task;
 282         struct mm_struct *mm;
 283 #ifdef CONFIG_MMU
 284         struct vm_area_struct *tail_vma;
 285 #endif
 286 #ifdef CONFIG_NUMA
 287         struct mempolicy *task_mempolicy;
 288 #endif
 289 } __randomize_layout;
 290
 291 struct mm_struct *proc_mem_open(struct inode *inode, unsigned int mode);
 292
 293 extern const struct file_operations proc_pid_maps_operations;
 294 extern const struct file_operations proc_pid_numa_maps_operations;
 295 extern const struct file_operations proc_pid_smaps_operations;
 296 extern const struct file_operations proc_pid_smaps_rollup_operations;
 297 extern const struct file_operations proc_clear_refs_operations;
 298 extern const struct file_operations proc_pagemap_operations;
 299
 300 extern unsigned long task_vsize(struct mm_struct *);
 301 extern unsigned long task_statm(struct mm_struct *,
 302                                 unsigned long *, unsigned long *,
 303                                 unsigned long *, unsigned long *);
 304 extern void task_mem(struct seq_file *, struct mm_struct *);