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