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1/* SPDX-License-Identifier: GPL-2.0-or-later */2/* Internal procfs definitions3 *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#include <linux/mm.h>17 18struct ctl_table_header;19struct mempolicy;20 21/*22 * This is not completely implemented yet. The idea is to23 * create an in-memory tree (like the actual /proc filesystem24 * tree) of these proc_dir_entries, so that we can dynamically25 * add new files to /proc.26 *27 * parent/subdir are used for the directory structure (every /proc file has a28 * parent, but "subdir" is empty for all non-directory entries).29 * subdir_node is used to build the rb tree "subdir" of the parent.30 */31struct proc_dir_entry {32 /*33 * number of callers into module in progress;34 * negative -> it's going away RSN35 */36 atomic_t in_use;37 refcount_t refcnt;38 struct list_head pde_openers; /* who did ->open, but not ->release */39 /* protects ->pde_openers and all struct pde_opener instances */40 spinlock_t pde_unload_lock;41 struct completion *pde_unload_completion;42 const struct inode_operations *proc_iops;43 union {44 const struct proc_ops *proc_ops;45 const struct file_operations *proc_dir_ops;46 };47 const struct dentry_operations *proc_dops;48 union {49 const struct seq_operations *seq_ops;50 int (*single_show)(struct seq_file *, void *);51 };52 proc_write_t write;53 void *data;54 unsigned int state_size;55 unsigned int low_ino;56 nlink_t nlink;57 kuid_t uid;58 kgid_t gid;59 loff_t size;60 struct proc_dir_entry *parent;61 struct rb_root subdir;62 struct rb_node subdir_node;63 char *name;64 umode_t mode;65 u8 flags;66 u8 namelen;67 char inline_name[];68} __randomize_layout;69 70#define SIZEOF_PDE ( \71 sizeof(struct proc_dir_entry) < 128 ? 128 : \72 sizeof(struct proc_dir_entry) < 192 ? 192 : \73 sizeof(struct proc_dir_entry) < 256 ? 256 : \74 sizeof(struct proc_dir_entry) < 512 ? 512 : \75 0)76#define SIZEOF_PDE_INLINE_NAME (SIZEOF_PDE - sizeof(struct proc_dir_entry))77 78static inline bool pde_is_permanent(const struct proc_dir_entry *pde)79{80 return pde->flags & PROC_ENTRY_PERMANENT;81}82 83static inline void pde_make_permanent(struct proc_dir_entry *pde)84{85 pde->flags |= PROC_ENTRY_PERMANENT;86}87 88extern struct kmem_cache *proc_dir_entry_cache;89void pde_free(struct proc_dir_entry *pde);90 91union proc_op {92 int (*proc_get_link)(struct dentry *, struct path *);93 int (*proc_show)(struct seq_file *m,94 struct pid_namespace *ns, struct pid *pid,95 struct task_struct *task);96 int lsmid;97};98 99struct proc_inode {100 struct pid *pid;101 unsigned int fd;102 union proc_op op;103 struct proc_dir_entry *pde;104 struct ctl_table_header *sysctl;105 struct ctl_table *sysctl_entry;106 struct hlist_node sibling_inodes;107 const struct proc_ns_operations *ns_ops;108 struct inode vfs_inode;109} __randomize_layout;110 111/*112 * General functions113 */114static inline struct proc_inode *PROC_I(const struct inode *inode)115{116 return container_of(inode, struct proc_inode, vfs_inode);117}118 119static inline struct proc_dir_entry *PDE(const struct inode *inode)120{121 return PROC_I(inode)->pde;122}123 124static inline struct pid *proc_pid(const struct inode *inode)125{126 return PROC_I(inode)->pid;127}128 129static inline struct task_struct *get_proc_task(const struct inode *inode)130{131 return get_pid_task(proc_pid(inode), PIDTYPE_PID);132}133 134void task_dump_owner(struct task_struct *task, umode_t mode,135 kuid_t *ruid, kgid_t *rgid);136 137unsigned name_to_int(const struct qstr *qstr);138/*139 * Offset of the first process in the /proc root directory..140 */141#define FIRST_PROCESS_ENTRY 256142 143/* Worst case buffer size needed for holding an integer. */144#define PROC_NUMBUF 13145 146/**147 * folio_precise_page_mapcount() - Number of mappings of this folio page.148 * @folio: The folio.149 * @page: The page.150 *151 * The number of present user page table entries that reference this page152 * as tracked via the RMAP: either referenced directly (PTE) or as part of153 * a larger area that covers this page (e.g., PMD).154 *155 * Use this function only for the calculation of existing statistics156 * (USS, PSS, mapcount_max) and for debugging purposes (/proc/kpagecount).157 *158 * Do not add new users.159 *160 * Returns: The number of mappings of this folio page. 0 for161 * folios that are not mapped to user space or are not tracked via the RMAP162 * (e.g., shared zeropage).163 */164static inline int folio_precise_page_mapcount(struct folio *folio,165 struct page *page)166{167 int mapcount = atomic_read(&page->_mapcount) + 1;168 169 if (page_mapcount_is_type(mapcount))170 mapcount = 0;171 if (folio_test_large(folio))172 mapcount += folio_entire_mapcount(folio);173 174 return mapcount;175}176 177/*178 * array.c179 */180extern const struct file_operations proc_tid_children_operations;181 182extern void proc_task_name(struct seq_file *m, struct task_struct *p,183 bool escape);184extern int proc_tid_stat(struct seq_file *, struct pid_namespace *,185 struct pid *, struct task_struct *) HWJS_SUSPENDS;186extern int proc_tgid_stat(struct seq_file *, struct pid_namespace *,187 struct pid *, struct task_struct *) HWJS_SUSPENDS;188extern int proc_pid_status(struct seq_file *, struct pid_namespace *,189 struct pid *, struct task_struct *);190extern int proc_pid_statm(struct seq_file *, struct pid_namespace *,191 struct pid *, struct task_struct *);192 193/*194 * base.c195 */196extern const struct dentry_operations pid_dentry_operations;197extern int pid_getattr(struct mnt_idmap *, const struct path *,198 struct kstat *, u32, unsigned int);199extern int proc_setattr(struct mnt_idmap *, struct dentry *,200 struct iattr *);201extern void proc_pid_evict_inode(struct proc_inode *);202extern struct inode *proc_pid_make_inode(struct super_block *, struct task_struct *, umode_t) HWJS_SUSPENDS;203extern void pid_update_inode(struct task_struct *, struct inode *);204extern int pid_delete_dentry(const struct dentry *);205extern int proc_pid_readdir(struct file *, struct dir_context *) HWJS_SUSPENDS;206struct dentry *proc_pid_lookup(struct dentry *, unsigned int) HWJS_SUSPENDS;207extern loff_t mem_lseek(struct file *, loff_t, int);208 209/* Lookups */210typedef struct dentry *instantiate_t(struct dentry *,211 struct task_struct *, const void *);212bool proc_fill_cache(struct file *, struct dir_context *, const char *, unsigned int,213 instantiate_t, struct task_struct *, const void *) HWJS_SUSPENDS;214 215/*216 * generic.c217 */218struct proc_dir_entry *proc_create_reg(const char *name, umode_t mode,219 struct proc_dir_entry **parent, void *data);220struct proc_dir_entry *proc_register(struct proc_dir_entry *dir,221 struct proc_dir_entry *dp);222extern struct dentry *proc_lookup(struct inode *, struct dentry *, unsigned int) HWJS_SUSPENDS;223struct dentry *proc_lookup_de(struct inode *, struct dentry *, struct proc_dir_entry *) HWJS_SUSPENDS;224extern int proc_readdir(struct file *, struct dir_context *);225int proc_readdir_de(struct file *, struct dir_context *, struct proc_dir_entry *);226 227static inline void pde_get(struct proc_dir_entry *pde)228{229 refcount_inc(&pde->refcnt);230}231extern void pde_put(struct proc_dir_entry *);232 233static inline bool is_empty_pde(const struct proc_dir_entry *pde)234{235 return S_ISDIR(pde->mode) && !pde->proc_iops;236}237extern ssize_t proc_simple_write(struct file *, const char __user *, size_t, loff_t *) HWJS_SUSPENDS;238 239/*240 * inode.c241 */242struct pde_opener {243 struct list_head lh;244 struct file *file;245 bool closing;246 struct completion *c;247} __randomize_layout;248extern const struct inode_operations proc_link_inode_operations;249extern const struct inode_operations proc_pid_link_inode_operations;250extern const struct super_operations proc_sops;251 252void proc_init_kmemcache(void);253void proc_invalidate_siblings_dcache(struct hlist_head *inodes, spinlock_t *lock) HWJS_SUSPENDS;254void set_proc_pid_nlink(void);255extern struct inode *proc_get_inode(struct super_block *, struct proc_dir_entry *);256extern void proc_entry_rundown(struct proc_dir_entry *) HWJS_SUSPENDS;257 258/*259 * proc_namespaces.c260 */261extern const struct inode_operations proc_ns_dir_inode_operations;262extern const struct file_operations proc_ns_dir_operations;263 264/*265 * proc_net.c266 */267extern const struct file_operations proc_net_operations;268extern const struct inode_operations proc_net_inode_operations;269 270#ifdef CONFIG_NET271extern int proc_net_init(void);272#else273static inline int proc_net_init(void) { return 0; }274#endif275 276/*277 * proc_self.c278 */279extern int proc_setup_self(struct super_block *);280 281/*282 * proc_thread_self.c283 */284extern int proc_setup_thread_self(struct super_block *) HWJS_SUSPENDS;285extern void proc_thread_self_init(void);286 287/*288 * proc_sysctl.c289 */290#ifdef CONFIG_PROC_SYSCTL291extern int proc_sys_init(void);292extern void proc_sys_evict_inode(struct inode *inode,293 struct ctl_table_header *head) HWJS_SUSPENDS;294#else295static inline void proc_sys_init(void) { }296static inline void proc_sys_evict_inode(struct inode *inode,297 struct ctl_table_header *head) { }298#endif299 300/*301 * proc_tty.c302 */303#ifdef CONFIG_TTY304extern void proc_tty_init(void);305#else306static inline void proc_tty_init(void) {}307#endif308 309/*310 * root.c311 */312extern struct proc_dir_entry proc_root;313 314extern void proc_self_init(void);315 316/*317 * task_[no]mmu.c318 */319struct mem_size_stats;320struct proc_maps_private {321 struct inode *inode;322 struct task_struct *task;323 struct mm_struct *mm;324 struct vma_iterator iter;325#ifdef CONFIG_NUMA326 struct mempolicy *task_mempolicy;327#endif328} __randomize_layout;329 330struct mm_struct *proc_mem_open(struct inode *inode, unsigned int mode) HWJS_SUSPENDS;331 332extern const struct file_operations proc_pid_maps_operations;333extern const struct file_operations proc_pid_numa_maps_operations;334extern const struct file_operations proc_pid_smaps_operations;335extern const struct file_operations proc_pid_smaps_rollup_operations;336extern const struct file_operations proc_clear_refs_operations;337extern const struct file_operations proc_pagemap_operations;338 339extern unsigned long task_vsize(struct mm_struct *);340extern unsigned long task_statm(struct mm_struct *,341 unsigned long *, unsigned long *,342 unsigned long *, unsigned long *);343extern void task_mem(struct seq_file *, struct mm_struct *);344 345extern const struct dentry_operations proc_net_dentry_ops;346static inline void pde_force_lookup(struct proc_dir_entry *pde)347{348 /* /proc/net/ entries can be changed under us by setns(CLONE_NEWNET) */349 pde->proc_dops = &proc_net_dentry_ops;350}351 352/*353 * Add a new procfs dentry that can't serve as a mountpoint. That should354 * encompass anything that is ephemeral and can just disappear while the355 * process is still around.356 */357static inline struct dentry *proc_splice_unmountable(struct inode *inode,358 struct dentry *dentry, const struct dentry_operations *d_ops)359{360 d_set_d_op(dentry, d_ops);361 dont_mount(dentry);362 return d_splice_alias(inode, dentry);363}364