LXR linux/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
  17struct ctl_table_header;
  18struct 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 */
  30struct 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
  77static inline bool pde_is_permanent(const struct proc_dir_entry *pde)
  78{
  79        return pde->flags & PROC_ENTRY_PERMANENT;
  80}
  81
  82extern struct kmem_cache *proc_dir_entry_cache;
  83void pde_free(struct proc_dir_entry *pde);
  84
  85union 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
  93struct 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 */
 108static inline struct proc_inode *PROC_I(const struct inode *inode)
 109{
 110        return container_of(inode, struct proc_inode, vfs_inode);
 111}
 112
 113static inline struct proc_dir_entry *PDE(const struct inode *inode)
 114{
 115        return PROC_I(inode)->pde;
 116}
 117
 118static inline struct pid *proc_pid(const struct inode *inode)
 119{
 120        return PROC_I(inode)->pid;
 121}
 122
 123static inline struct task_struct *get_proc_task(const struct inode *inode)
 124{
 125        return get_pid_task(proc_pid(inode), PIDTYPE_PID);
 126}
 127
 128void task_dump_owner(struct task_struct *task, umode_t mode,
 129                     kuid_t *ruid, kgid_t *rgid);
 130
 131unsigned 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 */
 143extern const struct file_operations proc_tid_children_operations;
 144
 145extern void proc_task_name(struct seq_file *m, struct task_struct *p,
 146                           bool escape);
 147extern int proc_tid_stat(struct seq_file *, struct pid_namespace *,
 148                         struct pid *, struct task_struct *);
 149extern int proc_tgid_stat(struct seq_file *, struct pid_namespace *,
 150                          struct pid *, struct task_struct *);
 151extern int proc_pid_status(struct seq_file *, struct pid_namespace *,
 152                           struct pid *, struct task_struct *);
 153extern int proc_pid_statm(struct seq_file *, struct pid_namespace *,
 154                          struct pid *, struct task_struct *);
 155
 156/*
 157 * base.c
 158 */
 159extern const struct dentry_operations pid_dentry_operations;
 160extern int pid_getattr(struct user_namespace *, const struct path *,
 161                       struct kstat *, u32, unsigned int);
 162extern int proc_setattr(struct user_namespace *, struct dentry *,
 163                        struct iattr *);
 164extern void proc_pid_evict_inode(struct proc_inode *);
 165extern struct inode *proc_pid_make_inode(struct super_block *, struct task_struct *, umode_t);
 166extern void pid_update_inode(struct task_struct *, struct inode *);
 167extern int pid_delete_dentry(const struct dentry *);
 168extern int proc_pid_readdir(struct file *, struct dir_context *);
 169struct dentry *proc_pid_lookup(struct dentry *, unsigned int);
 170extern loff_t mem_lseek(struct file *, loff_t, int);
 171
 172/* Lookups */
 173typedef struct dentry *instantiate_t(struct dentry *,
 174                                     struct task_struct *, const void *);
 175bool 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 */
 181struct proc_dir_entry *proc_create_reg(const char *name, umode_t mode,
 182                struct proc_dir_entry **parent, void *data);
 183struct proc_dir_entry *proc_register(struct proc_dir_entry *dir,
 184                struct proc_dir_entry *dp);
 185extern struct dentry *proc_lookup(struct inode *, struct dentry *, unsigned int);
 186struct dentry *proc_lookup_de(struct inode *, struct dentry *, struct proc_dir_entry *);
 187extern int proc_readdir(struct file *, struct dir_context *);
 188int proc_readdir_de(struct file *, struct dir_context *, struct proc_dir_entry *);
 189
 190static inline void pde_get(struct proc_dir_entry *pde)
 191{
 192        refcount_inc(&pde->refcnt);
 193}
 194extern void pde_put(struct proc_dir_entry *);
 195
 196static inline bool is_empty_pde(const struct proc_dir_entry *pde)
 197{
 198        return S_ISDIR(pde->mode) && !pde->proc_iops;
 199}
 200extern ssize_t proc_simple_write(struct file *, const char __user *, size_t, loff_t *);
 201
 202/*
 203 * inode.c
 204 */
 205struct pde_opener {
 206        struct list_head lh;
 207        struct file *file;
 208        bool closing;
 209        struct completion *c;
 210} __randomize_layout;
 211extern const struct inode_operations proc_link_inode_operations;
 212extern const struct inode_operations proc_pid_link_inode_operations;
 213extern const struct super_operations proc_sops;
 214
 215void proc_init_kmemcache(void);
 216void proc_invalidate_siblings_dcache(struct hlist_head *inodes, spinlock_t *lock);
 217void set_proc_pid_nlink(void);
 218extern struct inode *proc_get_inode(struct super_block *, struct proc_dir_entry *);
 219extern void proc_entry_rundown(struct proc_dir_entry *);
 220
 221/*
 222 * proc_namespaces.c
 223 */
 224extern const struct inode_operations proc_ns_dir_inode_operations;
 225extern const struct file_operations proc_ns_dir_operations;
 226
 227/*
 228 * proc_net.c
 229 */
 230extern const struct file_operations proc_net_operations;
 231extern const struct inode_operations proc_net_inode_operations;
 232
 233#ifdef CONFIG_NET
 234extern int proc_net_init(void);
 235#else
 236static inline int proc_net_init(void) { return 0; }
 237#endif
 238
 239/*
 240 * proc_self.c
 241 */
 242extern int proc_setup_self(struct super_block *);
 243
 244/*
 245 * proc_thread_self.c
 246 */
 247extern int proc_setup_thread_self(struct super_block *);
 248extern void proc_thread_self_init(void);
 249
 250/*
 251 * proc_sysctl.c
 252 */
 253#ifdef CONFIG_PROC_SYSCTL
 254extern int proc_sys_init(void);
 255extern void proc_sys_evict_inode(struct inode *inode,
 256                                 struct ctl_table_header *head);
 257#else
 258static inline void proc_sys_init(void) { }
 259static 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
 267extern void proc_tty_init(void);
 268#else
 269static inline void proc_tty_init(void) {}
 270#endif
 271
 272/*
 273 * root.c
 274 */
 275extern struct proc_dir_entry proc_root;
 276
 277extern void proc_self_init(void);
 278
 279/*
 280 * task_[no]mmu.c
 281 */
 282struct mem_size_stats;
 283struct 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
 295struct mm_struct *proc_mem_open(struct inode *inode, unsigned int mode);
 296
 297extern const struct file_operations proc_pid_maps_operations;
 298extern const struct file_operations proc_pid_numa_maps_operations;
 299extern const struct file_operations proc_pid_smaps_operations;
 300extern const struct file_operations proc_pid_smaps_rollup_operations;
 301extern const struct file_operations proc_clear_refs_operations;
 302extern const struct file_operations proc_pagemap_operations;
 303
 304extern unsigned long task_vsize(struct mm_struct *);
 305extern unsigned long task_statm(struct mm_struct *,
 306                                unsigned long *, unsigned long *,
 307                                unsigned long *, unsigned long *);
 308extern void task_mem(struct seq_file *, struct mm_struct *);
 309
 310extern const struct dentry_operations proc_net_dentry_ops;
 311static 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