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         const struct file_operations *proc_fops;
  43         const struct dentry_operations *proc_dops;
  44         union {
  45                 const struct seq_operations *seq_ops;
  46                 int (*single_show)(struct seq_file *, void *);
  47         };
  48         proc_write_t write;
  49         void *data;
  50         unsigned int state_size;
  51         unsigned int low_ino;
  52         nlink_t nlink;
  53         kuid_t uid;
  54         kgid_t gid;
  55         loff_t size;
  56         struct proc_dir_entry *parent;
  57         struct rb_root subdir;
  58         struct rb_node subdir_node;
  59         char *name;
  60         umode_t mode;
  61         u8 namelen;
  62         char inline_name[];
  63 } __randomize_layout;
  64
  65 #define SIZEOF_PDE      (                               \
  66         sizeof(struct proc_dir_entry) < 128 ? 128 :     \
  67         sizeof(struct proc_dir_entry) < 192 ? 192 :     \
  68         sizeof(struct proc_dir_entry) < 256 ? 256 :     \
  69         sizeof(struct proc_dir_entry) < 512 ? 512 :     \
  70         0)
  71 #define SIZEOF_PDE_INLINE_NAME (SIZEOF_PDE - sizeof(struct proc_dir_entry))
  72
  73 extern struct kmem_cache *proc_dir_entry_cache;
  74 void pde_free(struct proc_dir_entry *pde);
  75
  76 union proc_op {
  77         int (*proc_get_link)(struct dentry *, struct path *);
  78         int (*proc_show)(struct seq_file *m,
  79                 struct pid_namespace *ns, struct pid *pid,
  80                 struct task_struct *task);
  81         const char *lsm;
  82 };
  83
  84 struct proc_inode {
  85         struct pid *pid;
  86         unsigned int fd;
  87         union proc_op op;
  88         struct proc_dir_entry *pde;
  89         struct ctl_table_header *sysctl;
  90         struct ctl_table *sysctl_entry;
  91         struct hlist_node sysctl_inodes;
  92         const struct proc_ns_operations *ns_ops;
  93         struct inode vfs_inode;
  94 } __randomize_layout;
  95
  96 /*
  97  * General functions
  98  */
  99 static inline struct proc_inode *PROC_I(const struct inode *inode)
 100 {
 101         return container_of(inode, struct proc_inode, vfs_inode);
 102 }
 103
 104 static inline struct proc_dir_entry *PDE(const struct inode *inode)
 105 {
 106         return PROC_I(inode)->pde;
 107 }
 108
 109 static inline void *__PDE_DATA(const struct inode *inode)
 110 {
 111         return PDE(inode)->data;
 112 }
 113
 114 static inline struct pid *proc_pid(const struct inode *inode)
 115 {
 116         return PROC_I(inode)->pid;
 117 }
 118
 119 static inline struct task_struct *get_proc_task(const struct inode *inode)
 120 {
 121         return get_pid_task(proc_pid(inode), PIDTYPE_PID);
 122 }
 123
 124 void task_dump_owner(struct task_struct *task, umode_t mode,
 125                      kuid_t *ruid, kgid_t *rgid);
 126
 127 unsigned name_to_int(const struct qstr *qstr);
 128 /*
 129  * Offset of the first process in the /proc root directory..
 130  */
 131 #define FIRST_PROCESS_ENTRY 256
 132
 133 /* Worst case buffer size needed for holding an integer. */
 134 #define PROC_NUMBUF 13
 135
 136 /*
 137  * array.c
 138  */
 139 extern const struct file_operations proc_tid_children_operations;
 140
 141 extern void proc_task_name(struct seq_file *m, struct task_struct *p,
 142                            bool escape);
 143 extern int proc_tid_stat(struct seq_file *, struct pid_namespace *,
 144                          struct pid *, struct task_struct *);
 145 extern int proc_tgid_stat(struct seq_file *, struct pid_namespace *,
 146                           struct pid *, struct task_struct *);
 147 extern int proc_pid_status(struct seq_file *, struct pid_namespace *,
 148                            struct pid *, struct task_struct *);
 149 extern int proc_pid_statm(struct seq_file *, struct pid_namespace *,
 150                           struct pid *, struct task_struct *);
 151
 152 /*
 153  * base.c
 154  */
 155 extern const struct dentry_operations pid_dentry_operations;
 156 extern int pid_getattr(const struct path *, struct kstat *, u32, unsigned int);
 157 extern int proc_setattr(struct dentry *, struct iattr *);
 158 extern struct inode *proc_pid_make_inode(struct super_block *, struct task_struct *, umode_t);
 159 extern void pid_update_inode(struct task_struct *, struct inode *);
 160 extern int pid_delete_dentry(const struct dentry *);
 161 extern int proc_pid_readdir(struct file *, struct dir_context *);
 162 struct dentry *proc_pid_lookup(struct dentry *, unsigned int);
 163 extern loff_t mem_lseek(struct file *, loff_t, int);
 164
 165 /* Lookups */
 166 typedef struct dentry *instantiate_t(struct dentry *,
 167                                      struct task_struct *, const void *);
 168 bool proc_fill_cache(struct file *, struct dir_context *, const char *, unsigned int,
 169                            instantiate_t, struct task_struct *, const void *);
 170
 171 /*
 172  * generic.c
 173  */
 174 struct proc_dir_entry *proc_create_reg(const char *name, umode_t mode,
 175                 struct proc_dir_entry **parent, void *data);
 176 struct proc_dir_entry *proc_register(struct proc_dir_entry *dir,
 177                 struct proc_dir_entry *dp);
 178 extern struct dentry *proc_lookup(struct inode *, struct dentry *, unsigned int);
 179 struct dentry *proc_lookup_de(struct inode *, struct dentry *, struct proc_dir_entry *);
 180 extern int proc_readdir(struct file *, struct dir_context *);
 181 int proc_readdir_de(struct file *, struct dir_context *, struct proc_dir_entry *);
 182
 183 static inline struct proc_dir_entry *pde_get(struct proc_dir_entry *pde)
 184 {
 185         refcount_inc(&pde->refcnt);
 186         return pde;
 187 }
 188 extern void pde_put(struct proc_dir_entry *);
 189
 190 static inline bool is_empty_pde(const struct proc_dir_entry *pde)
 191 {
 192         return S_ISDIR(pde->mode) && !pde->proc_iops;
 193 }
 194 extern ssize_t proc_simple_write(struct file *, const char __user *, size_t, loff_t *);
 195
 196 /*
 197  * inode.c
 198  */
 199 struct pde_opener {
 200         struct list_head lh;
 201         struct file *file;
 202         bool closing;
 203         struct completion *c;
 204 } __randomize_layout;
 205 extern const struct inode_operations proc_link_inode_operations;
 206 extern const struct inode_operations proc_pid_link_inode_operations;
 207 extern const struct super_operations proc_sops;
 208
 209 void proc_init_kmemcache(void);
 210 void set_proc_pid_nlink(void);
 211 extern struct inode *proc_get_inode(struct super_block *, struct proc_dir_entry *);
 212 extern void proc_entry_rundown(struct proc_dir_entry *);
 213
 214 /*
 215  * proc_namespaces.c
 216  */
 217 extern const struct inode_operations proc_ns_dir_inode_operations;
 218 extern const struct file_operations proc_ns_dir_operations;
 219
 220 /*
 221  * proc_net.c
 222  */
 223 extern const struct file_operations proc_net_operations;
 224 extern const struct inode_operations proc_net_inode_operations;
 225
 226 #ifdef CONFIG_NET
 227 extern int proc_net_init(void);
 228 #else
 229 static inline int proc_net_init(void) { return 0; }
 230 #endif
 231
 232 /*
 233  * proc_self.c
 234  */
 235 extern int proc_setup_self(struct super_block *);
 236
 237 /*
 238  * proc_thread_self.c
 239  */
 240 extern int proc_setup_thread_self(struct super_block *);
 241 extern void proc_thread_self_init(void);
 242
 243 /*
 244  * proc_sysctl.c
 245  */
 246 #ifdef CONFIG_PROC_SYSCTL
 247 extern int proc_sys_init(void);
 248 extern void proc_sys_evict_inode(struct inode *inode,
 249                                  struct ctl_table_header *head);
 250 #else
 251 static inline void proc_sys_init(void) { }
 252 static inline void proc_sys_evict_inode(struct  inode *inode,
 253                                         struct ctl_table_header *head) { }
 254 #endif
 255
 256 /*
 257  * proc_tty.c
 258  */
 259 #ifdef CONFIG_TTY
 260 extern void proc_tty_init(void);
 261 #else
 262 static inline void proc_tty_init(void) {}
 263 #endif
 264
 265 /*
 266  * root.c
 267  */
 268 extern struct proc_dir_entry proc_root;
 269
 270 extern void proc_self_init(void);
 271
 272 /*
 273  * task_[no]mmu.c
 274  */
 275 struct mem_size_stats;
 276 struct proc_maps_private {
 277         struct inode *inode;
 278         struct task_struct *task;
 279         struct mm_struct *mm;
 280 #ifdef CONFIG_MMU
 281         struct vm_area_struct *tail_vma;
 282 #endif
 283 #ifdef CONFIG_NUMA
 284         struct mempolicy *task_mempolicy;
 285 #endif
 286 } __randomize_layout;
 287
 288 struct mm_struct *proc_mem_open(struct inode *inode, unsigned int mode);
 289
 290 extern const struct file_operations proc_pid_maps_operations;
 291 extern const struct file_operations proc_pid_numa_maps_operations;
 292 extern const struct file_operations proc_pid_smaps_operations;
 293 extern const struct file_operations proc_pid_smaps_rollup_operations;
 294 extern const struct file_operations proc_clear_refs_operations;
 295 extern const struct file_operations proc_pagemap_operations;
 296
 297 extern unsigned long task_vsize(struct mm_struct *);
 298 extern unsigned long task_statm(struct mm_struct *,
 299                                 unsigned long *, unsigned long *,
 300                                 unsigned long *, unsigned long *);
 301 extern void task_mem(struct seq_file *, struct mm_struct *);