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 pde_is_permanent(const struct proc_dir_entry * pde)78 static inline bool pde_is_permanent(const struct proc_dir_entry *pde) 79 { 80 return pde->flags & PROC_ENTRY_PERMANENT; 81 } 82 pde_make_permanent(struct proc_dir_entry * pde)83 static inline void pde_make_permanent(struct proc_dir_entry *pde) 84 { 85 pde->flags |= PROC_ENTRY_PERMANENT; 86 } 87 pde_has_proc_read_iter(const struct proc_dir_entry * pde)88 static inline bool pde_has_proc_read_iter(const struct proc_dir_entry *pde) 89 { 90 return pde->flags & PROC_ENTRY_proc_read_iter; 91 } 92 pde_has_proc_compat_ioctl(const struct proc_dir_entry * pde)93 static inline bool pde_has_proc_compat_ioctl(const struct proc_dir_entry *pde) 94 { 95 #ifdef CONFIG_COMPAT 96 return pde->flags & PROC_ENTRY_proc_compat_ioctl; 97 #else 98 return false; 99 #endif 100 } 101 102 extern struct kmem_cache *proc_dir_entry_cache; 103 void pde_free(struct proc_dir_entry *pde); 104 105 union proc_op { 106 int (*proc_get_link)(struct dentry *, struct path *); 107 int (*proc_show)(struct seq_file *m, 108 struct pid_namespace *ns, struct pid *pid, 109 struct task_struct *task); 110 int lsmid; 111 }; 112 113 struct proc_inode { 114 struct pid *pid; 115 unsigned int fd; 116 union proc_op op; 117 struct proc_dir_entry *pde; 118 struct ctl_table_header *sysctl; 119 const struct ctl_table *sysctl_entry; 120 struct hlist_node sibling_inodes; 121 const struct proc_ns_operations *ns_ops; 122 struct inode vfs_inode; 123 } __randomize_layout; 124 125 /* 126 * General functions 127 */ PROC_I(const struct inode * inode)128 static inline struct proc_inode *PROC_I(const struct inode *inode) 129 { 130 return container_of(inode, struct proc_inode, vfs_inode); 131 } 132 PDE(const struct inode * inode)133 static inline struct proc_dir_entry *PDE(const struct inode *inode) 134 { 135 return PROC_I(inode)->pde; 136 } 137 proc_pid(const struct inode * inode)138 static inline struct pid *proc_pid(const struct inode *inode) 139 { 140 return PROC_I(inode)->pid; 141 } 142 get_proc_task(const struct inode * inode)143 static inline struct task_struct *get_proc_task(const struct inode *inode) 144 { 145 return get_pid_task(proc_pid(inode), PIDTYPE_PID); 146 } 147 148 void task_dump_owner(struct task_struct *task, umode_t mode, 149 kuid_t *ruid, kgid_t *rgid); 150 151 unsigned name_to_int(const struct qstr *qstr); 152 /* 153 * Offset of the first process in the /proc root directory.. 154 */ 155 #define FIRST_PROCESS_ENTRY 256 156 157 /* Worst case buffer size needed for holding an integer. */ 158 #define PROC_NUMBUF 13 159 160 /** 161 * folio_precise_page_mapcount() - Number of mappings of this folio page. 162 * @folio: The folio. 163 * @page: The page. 164 * 165 * The number of present user page table entries that reference this page 166 * as tracked via the RMAP: either referenced directly (PTE) or as part of 167 * a larger area that covers this page (e.g., PMD). 168 * 169 * Use this function only for the calculation of existing statistics 170 * (USS, PSS, mapcount_max) and for debugging purposes (/proc/kpagecount). 171 * 172 * Do not add new users. 173 * 174 * Returns: The number of mappings of this folio page. 0 for 175 * folios that are not mapped to user space or are not tracked via the RMAP 176 * (e.g., shared zeropage). 177 */ folio_precise_page_mapcount(struct folio * folio,struct page * page)178 static inline int folio_precise_page_mapcount(struct folio *folio, 179 struct page *page) 180 { 181 int mapcount = atomic_read(&page->_mapcount) + 1; 182 183 if (page_mapcount_is_type(mapcount)) 184 mapcount = 0; 185 if (folio_test_large(folio)) 186 mapcount += folio_entire_mapcount(folio); 187 188 return mapcount; 189 } 190 191 /* 192 * array.c 193 */ 194 extern const struct file_operations proc_tid_children_operations; 195 196 extern void proc_task_name(struct seq_file *m, struct task_struct *p, 197 bool escape); 198 extern int proc_tid_stat(struct seq_file *, struct pid_namespace *, 199 struct pid *, struct task_struct *); 200 extern int proc_tgid_stat(struct seq_file *, struct pid_namespace *, 201 struct pid *, struct task_struct *); 202 extern int proc_pid_status(struct seq_file *, struct pid_namespace *, 203 struct pid *, struct task_struct *); 204 extern int proc_pid_statm(struct seq_file *, struct pid_namespace *, 205 struct pid *, struct task_struct *); 206 207 /* 208 * base.c 209 */ 210 extern const struct dentry_operations pid_dentry_operations; 211 extern int pid_getattr(struct mnt_idmap *, const struct path *, 212 struct kstat *, u32, unsigned int); 213 extern int proc_setattr(struct mnt_idmap *, struct dentry *, 214 struct iattr *); 215 extern void proc_pid_evict_inode(struct proc_inode *); 216 extern struct inode *proc_pid_make_inode(struct super_block *, struct task_struct *, umode_t); 217 extern void pid_update_inode(struct task_struct *, struct inode *); 218 extern int pid_delete_dentry(const struct dentry *); 219 extern int proc_pid_readdir(struct file *, struct dir_context *); 220 struct dentry *proc_pid_lookup(struct dentry *, unsigned int); 221 extern loff_t mem_lseek(struct file *, loff_t, int); 222 223 /* Lookups */ 224 typedef struct dentry *instantiate_t(struct dentry *, 225 struct task_struct *, const void *); 226 bool proc_fill_cache(struct file *, struct dir_context *, const char *, unsigned int, 227 instantiate_t, struct task_struct *, const void *); 228 229 /* 230 * generic.c 231 */ 232 struct proc_dir_entry *proc_create_reg(const char *name, umode_t mode, 233 struct proc_dir_entry **parent, void *data); 234 struct proc_dir_entry *proc_register(struct proc_dir_entry *dir, 235 struct proc_dir_entry *dp); 236 extern struct dentry *proc_lookup(struct inode *, struct dentry *, unsigned int); 237 struct dentry *proc_lookup_de(struct inode *, struct dentry *, struct proc_dir_entry *); 238 extern int proc_readdir(struct file *, struct dir_context *); 239 int proc_readdir_de(struct file *, struct dir_context *, struct proc_dir_entry *); 240 pde_get(struct proc_dir_entry * pde)241 static inline void pde_get(struct proc_dir_entry *pde) 242 { 243 refcount_inc(&pde->refcnt); 244 } 245 extern void pde_put(struct proc_dir_entry *); 246 is_empty_pde(const struct proc_dir_entry * pde)247 static inline bool is_empty_pde(const struct proc_dir_entry *pde) 248 { 249 return S_ISDIR(pde->mode) && !pde->proc_iops; 250 } 251 extern ssize_t proc_simple_write(struct file *, const char __user *, size_t, loff_t *); 252 253 /* 254 * inode.c 255 */ 256 struct pde_opener { 257 struct list_head lh; 258 struct file *file; 259 bool closing; 260 struct completion *c; 261 } __randomize_layout; 262 extern const struct inode_operations proc_link_inode_operations; 263 extern const struct inode_operations proc_pid_link_inode_operations; 264 extern const struct super_operations proc_sops; 265 266 void proc_init_kmemcache(void); 267 void proc_invalidate_siblings_dcache(struct hlist_head *inodes, spinlock_t *lock); 268 void set_proc_pid_nlink(void); 269 extern struct inode *proc_get_inode(struct super_block *, struct proc_dir_entry *); 270 extern void proc_entry_rundown(struct proc_dir_entry *); 271 272 /* 273 * proc_namespaces.c 274 */ 275 extern const struct inode_operations proc_ns_dir_inode_operations; 276 extern const struct file_operations proc_ns_dir_operations; 277 278 /* 279 * proc_net.c 280 */ 281 extern const struct file_operations proc_net_operations; 282 extern const struct inode_operations proc_net_inode_operations; 283 284 #ifdef CONFIG_NET 285 extern int proc_net_init(void); 286 #else proc_net_init(void)287 static inline int proc_net_init(void) { return 0; } 288 #endif 289 290 /* 291 * proc_self.c 292 */ 293 extern int proc_setup_self(struct super_block *); 294 295 /* 296 * proc_thread_self.c 297 */ 298 extern int proc_setup_thread_self(struct super_block *); 299 extern void proc_thread_self_init(void); 300 301 /* 302 * proc_sysctl.c 303 */ 304 #ifdef CONFIG_PROC_SYSCTL 305 extern int proc_sys_init(void); 306 extern void proc_sys_evict_inode(struct inode *inode, 307 struct ctl_table_header *head); 308 #else proc_sys_init(void)309 static inline void proc_sys_init(void) { } proc_sys_evict_inode(struct inode * inode,struct ctl_table_header * head)310 static inline void proc_sys_evict_inode(struct inode *inode, 311 struct ctl_table_header *head) { } 312 #endif 313 314 /* 315 * proc_tty.c 316 */ 317 #ifdef CONFIG_TTY 318 extern void proc_tty_init(void); 319 #else proc_tty_init(void)320 static inline void proc_tty_init(void) {} 321 #endif 322 323 /* 324 * root.c 325 */ 326 extern struct proc_dir_entry proc_root; 327 328 extern void proc_self_init(void); 329 330 /* 331 * task_[no]mmu.c 332 */ 333 struct mem_size_stats; 334 struct proc_maps_private { 335 struct inode *inode; 336 struct task_struct *task; 337 struct mm_struct *mm; 338 struct vma_iterator iter; 339 #ifdef CONFIG_NUMA 340 struct mempolicy *task_mempolicy; 341 #endif 342 } __randomize_layout; 343 344 struct mm_struct *proc_mem_open(struct inode *inode, unsigned int mode); 345 346 extern const struct file_operations proc_pid_maps_operations; 347 extern const struct file_operations proc_pid_numa_maps_operations; 348 extern const struct file_operations proc_pid_smaps_operations; 349 extern const struct file_operations proc_pid_smaps_rollup_operations; 350 extern const struct file_operations proc_clear_refs_operations; 351 extern const struct file_operations proc_pagemap_operations; 352 353 extern unsigned long task_vsize(struct mm_struct *); 354 extern unsigned long task_statm(struct mm_struct *, 355 unsigned long *, unsigned long *, 356 unsigned long *, unsigned long *); 357 extern void task_mem(struct seq_file *, struct mm_struct *); 358 359 extern const struct dentry_operations proc_net_dentry_ops; pde_force_lookup(struct proc_dir_entry * pde)360 static inline void pde_force_lookup(struct proc_dir_entry *pde) 361 { 362 /* /proc/net/ entries can be changed under us by setns(CLONE_NEWNET) */ 363 pde->proc_dops = &proc_net_dentry_ops; 364 } 365 366 /* 367 * Add a new procfs dentry that can't serve as a mountpoint. That should 368 * encompass anything that is ephemeral and can just disappear while the 369 * process is still around. 370 */ proc_splice_unmountable(struct inode * inode,struct dentry * dentry,const struct dentry_operations * d_ops)371 static inline struct dentry *proc_splice_unmountable(struct inode *inode, 372 struct dentry *dentry, const struct dentry_operations *d_ops) 373 { 374 d_set_d_op(dentry, d_ops); 375 dont_mount(dentry); 376 return d_splice_alias(inode, dentry); 377 } 378