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 #include <linux/mm.h> 17 18 struct ctl_table_header; 19 struct mempolicy; 20 21 /* 22 * This is not completely implemented yet. The idea is to 23 * create an in-memory tree (like the actual /proc filesystem 24 * tree) of these proc_dir_entries, so that we can dynamically 25 * add new files to /proc. 26 * 27 * parent/subdir are used for the directory structure (every /proc file has a 28 * 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 */ 31 struct proc_dir_entry { 32 /* 33 * number of callers into module in progress; 34 * negative -> it's going away RSN 35 */ 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 78 static inline bool pde_is_permanent(const struct proc_dir_entry *pde) 79 { 80 return pde->flags & PROC_ENTRY_PERMANENT; 81 } 82 83 static inline void pde_make_permanent(struct proc_dir_entry *pde) 84 { 85 pde->flags |= PROC_ENTRY_PERMANENT; 86 } 87 88 extern struct kmem_cache *proc_dir_entry_cache; 89 void pde_free(struct proc_dir_entry *pde); 90 91 union 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 99 struct 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 functions 113 */ 114 static inline struct proc_inode *PROC_I(const struct inode *inode) 115 { 116 return container_of(inode, struct proc_inode, vfs_inode); 117 } 118 119 static inline struct proc_dir_entry *PDE(const struct inode *inode) 120 { 121 return PROC_I(inode)->pde; 122 } 123 124 static inline struct pid *proc_pid(const struct inode *inode) 125 { 126 return PROC_I(inode)->pid; 127 } 128 129 static inline struct task_struct *get_proc_task(const struct inode *inode) 130 { 131 return get_pid_task(proc_pid(inode), PIDTYPE_PID); 132 } 133 134 void task_dump_owner(struct task_struct *task, umode_t mode, 135 kuid_t *ruid, kgid_t *rgid); 136 137 unsigned 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 256 142 143 /* Worst case buffer size needed for holding an integer. */ 144 #define PROC_NUMBUF 13 145 146 /** 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 page 152 * as tracked via the RMAP: either referenced directly (PTE) or as part of 153 * a larger area that covers this page (e.g., PMD). 154 * 155 * Use this function only for the calculation of existing statistics 156 * (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 for 161 * folios that are not mapped to user space or are not tracked via the RMAP 162 * (e.g., shared zeropage). 163 */ 164 static inline int folio_precise_page_mapcount(struct folio *folio, 165 struct page *page) 166 { 167 int mapcount = atomic_read(&page->_mapcount) + 1; 168 169 /* Handle page_has_type() pages */ 170 if (mapcount < PAGE_MAPCOUNT_RESERVE + 1) 171 mapcount = 0; 172 if (folio_test_large(folio)) 173 mapcount += folio_entire_mapcount(folio); 174 175 return mapcount; 176 } 177 178 /* 179 * array.c 180 */ 181 extern const struct file_operations proc_tid_children_operations; 182 183 extern void proc_task_name(struct seq_file *m, struct task_struct *p, 184 bool escape); 185 extern int proc_tid_stat(struct seq_file *, struct pid_namespace *, 186 struct pid *, struct task_struct *); 187 extern int proc_tgid_stat(struct seq_file *, struct pid_namespace *, 188 struct pid *, struct task_struct *); 189 extern int proc_pid_status(struct seq_file *, struct pid_namespace *, 190 struct pid *, struct task_struct *); 191 extern int proc_pid_statm(struct seq_file *, struct pid_namespace *, 192 struct pid *, struct task_struct *); 193 194 /* 195 * base.c 196 */ 197 extern const struct dentry_operations pid_dentry_operations; 198 extern int pid_getattr(struct mnt_idmap *, const struct path *, 199 struct kstat *, u32, unsigned int); 200 extern int proc_setattr(struct mnt_idmap *, struct dentry *, 201 struct iattr *); 202 extern void proc_pid_evict_inode(struct proc_inode *); 203 extern struct inode *proc_pid_make_inode(struct super_block *, struct task_struct *, umode_t); 204 extern void pid_update_inode(struct task_struct *, struct inode *); 205 extern int pid_delete_dentry(const struct dentry *); 206 extern int proc_pid_readdir(struct file *, struct dir_context *); 207 struct dentry *proc_pid_lookup(struct dentry *, unsigned int); 208 extern loff_t mem_lseek(struct file *, loff_t, int); 209 210 /* Lookups */ 211 typedef struct dentry *instantiate_t(struct dentry *, 212 struct task_struct *, const void *); 213 bool proc_fill_cache(struct file *, struct dir_context *, const char *, unsigned int, 214 instantiate_t, struct task_struct *, const void *); 215 216 /* 217 * generic.c 218 */ 219 struct proc_dir_entry *proc_create_reg(const char *name, umode_t mode, 220 struct proc_dir_entry **parent, void *data); 221 struct proc_dir_entry *proc_register(struct proc_dir_entry *dir, 222 struct proc_dir_entry *dp); 223 extern struct dentry *proc_lookup(struct inode *, struct dentry *, unsigned int); 224 struct dentry *proc_lookup_de(struct inode *, struct dentry *, struct proc_dir_entry *); 225 extern int proc_readdir(struct file *, struct dir_context *); 226 int proc_readdir_de(struct file *, struct dir_context *, struct proc_dir_entry *); 227 228 static inline void pde_get(struct proc_dir_entry *pde) 229 { 230 refcount_inc(&pde->refcnt); 231 } 232 extern void pde_put(struct proc_dir_entry *); 233 234 static inline bool is_empty_pde(const struct proc_dir_entry *pde) 235 { 236 return S_ISDIR(pde->mode) && !pde->proc_iops; 237 } 238 extern ssize_t proc_simple_write(struct file *, const char __user *, size_t, loff_t *); 239 240 /* 241 * inode.c 242 */ 243 struct pde_opener { 244 struct list_head lh; 245 struct file *file; 246 bool closing; 247 struct completion *c; 248 } __randomize_layout; 249 extern const struct inode_operations proc_link_inode_operations; 250 extern const struct inode_operations proc_pid_link_inode_operations; 251 extern const struct super_operations proc_sops; 252 253 void proc_init_kmemcache(void); 254 void proc_invalidate_siblings_dcache(struct hlist_head *inodes, spinlock_t *lock); 255 void set_proc_pid_nlink(void); 256 extern struct inode *proc_get_inode(struct super_block *, struct proc_dir_entry *); 257 extern void proc_entry_rundown(struct proc_dir_entry *); 258 259 /* 260 * proc_namespaces.c 261 */ 262 extern const struct inode_operations proc_ns_dir_inode_operations; 263 extern const struct file_operations proc_ns_dir_operations; 264 265 /* 266 * proc_net.c 267 */ 268 extern const struct file_operations proc_net_operations; 269 extern const struct inode_operations proc_net_inode_operations; 270 271 #ifdef CONFIG_NET 272 extern int proc_net_init(void); 273 #else 274 static inline int proc_net_init(void) { return 0; } 275 #endif 276 277 /* 278 * proc_self.c 279 */ 280 extern int proc_setup_self(struct super_block *); 281 282 /* 283 * proc_thread_self.c 284 */ 285 extern int proc_setup_thread_self(struct super_block *); 286 extern void proc_thread_self_init(void); 287 288 /* 289 * proc_sysctl.c 290 */ 291 #ifdef CONFIG_PROC_SYSCTL 292 extern int proc_sys_init(void); 293 extern void proc_sys_evict_inode(struct inode *inode, 294 struct ctl_table_header *head); 295 #else 296 static inline void proc_sys_init(void) { } 297 static inline void proc_sys_evict_inode(struct inode *inode, 298 struct ctl_table_header *head) { } 299 #endif 300 301 /* 302 * proc_tty.c 303 */ 304 #ifdef CONFIG_TTY 305 extern void proc_tty_init(void); 306 #else 307 static inline void proc_tty_init(void) {} 308 #endif 309 310 /* 311 * root.c 312 */ 313 extern struct proc_dir_entry proc_root; 314 315 extern void proc_self_init(void); 316 317 /* 318 * task_[no]mmu.c 319 */ 320 struct mem_size_stats; 321 struct proc_maps_private { 322 struct inode *inode; 323 struct task_struct *task; 324 struct mm_struct *mm; 325 struct vma_iterator iter; 326 #ifdef CONFIG_NUMA 327 struct mempolicy *task_mempolicy; 328 #endif 329 } __randomize_layout; 330 331 struct mm_struct *proc_mem_open(struct inode *inode, unsigned int mode); 332 333 extern const struct file_operations proc_pid_maps_operations; 334 extern const struct file_operations proc_pid_numa_maps_operations; 335 extern const struct file_operations proc_pid_smaps_operations; 336 extern const struct file_operations proc_pid_smaps_rollup_operations; 337 extern const struct file_operations proc_clear_refs_operations; 338 extern const struct file_operations proc_pagemap_operations; 339 340 extern unsigned long task_vsize(struct mm_struct *); 341 extern unsigned long task_statm(struct mm_struct *, 342 unsigned long *, unsigned long *, 343 unsigned long *, unsigned long *); 344 extern void task_mem(struct seq_file *, struct mm_struct *); 345 346 extern const struct dentry_operations proc_net_dentry_ops; 347 static inline void pde_force_lookup(struct proc_dir_entry *pde) 348 { 349 /* /proc/net/ entries can be changed under us by setns(CLONE_NEWNET) */ 350 pde->proc_dops = &proc_net_dentry_ops; 351 } 352