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binder_internal.h
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linux-6.19.14/drivers/android/binder_internal.h
1/* SPDX-License-Identifier: GPL-2.0 */ 2 3#ifndef _LINUX_BINDER_INTERNAL_H 4#define _LINUX_BINDER_INTERNAL_H 5 6#include <linux/fs.h> 7#include <linux/list.h> 8#include <linux/miscdevice.h> 9#include <linux/mutex.h> 10#include <linux/refcount.h> 11#include <linux/stddef.h> 12#include <linux/types.h> 13#include <linux/uidgid.h> 14#include <uapi/linux/android/binderfs.h> 15#include "binder_alloc.h" 16#include "dbitmap.h" 17 18struct binder_context { 19 struct binder_node *binder_context_mgr_node; 20 struct mutex context_mgr_node_lock; 21 kuid_t binder_context_mgr_uid; 22 const char *name; 23}; 24 25/** 26 * struct binder_device - information about a binder device node 27 * @hlist: list of binder devices 28 * @miscdev: information about a binder character device node 29 * @context: binder context information 30 * @binderfs_inode: This is the inode of the root dentry of the super block 31 * belonging to a binderfs mount. 32 */ 33struct binder_device { 34 struct hlist_node hlist; 35 struct miscdevice miscdev; 36 struct binder_context context; 37 struct inode *binderfs_inode; 38 refcount_t ref; 39}; 40 41/** 42 * binderfs_mount_opts - mount options for binderfs 43 * @max: maximum number of allocatable binderfs binder devices 44 * @stats_mode: enable binder stats in binderfs. 45 */ 46struct binderfs_mount_opts { 47 int max; 48 int stats_mode; 49}; 50 51/** 52 * binderfs_info - information about a binderfs mount 53 * @ipc_ns: The ipc namespace the binderfs mount belongs to. 54 * @control_dentry: This records the dentry of this binderfs mount 55 * binder-control device. 56 * @root_uid: uid that needs to be used when a new binder device is 57 * created. 58 * @root_gid: gid that needs to be used when a new binder device is 59 * created. 60 * @mount_opts: The mount options in use. 61 * @device_count: The current number of allocated binder devices. 62 * @proc_log_dir: Pointer to the directory dentry containing process-specific 63 * logs. 64 */ 65struct binderfs_info { 66 struct ipc_namespace *ipc_ns; 67 struct dentry *control_dentry; 68 kuid_t root_uid; 69 kgid_t root_gid; 70 struct binderfs_mount_opts mount_opts; 71 int device_count; 72 struct dentry *proc_log_dir; 73}; 74 75extern const struct file_operations binder_fops; 76 77extern char *binder_devices_param; 78 79#ifdef CONFIG_ANDROID_BINDERFS 80extern bool is_binderfs_device(const struct inode *inode); 81extern struct dentry *binderfs_create_file(struct dentry *dir, const char *name, 82 const struct file_operations *fops, 83 void *data); 84#else 85static inline bool is_binderfs_device(const struct inode *inode) 86{ 87 return false; 88} 89static inline struct dentry *binderfs_create_file(struct dentry *dir, 90 const char *name, 91 const struct file_operations *fops, 92 void *data) 93{ 94 return NULL; 95} 96#endif 97 98#ifdef CONFIG_ANDROID_BINDERFS 99extern int __init init_binderfs(void); 100#else 101static inline int __init init_binderfs(void) 102{ 103 return 0; 104} 105#endif 106 107struct binder_debugfs_entry { 108 const char *name; 109 umode_t mode; 110 const struct file_operations *fops; 111 void *data; 112}; 113 114extern const struct binder_debugfs_entry binder_debugfs_entries[]; 115 116#define binder_for_each_debugfs_entry(entry) \ 117 for ((entry) = binder_debugfs_entries; \ 118 (entry)->name; \ 119 (entry)++) 120 121enum binder_stat_types { 122 BINDER_STAT_PROC, 123 BINDER_STAT_THREAD, 124 BINDER_STAT_NODE, 125 BINDER_STAT_REF, 126 BINDER_STAT_DEATH, 127 BINDER_STAT_TRANSACTION, 128 BINDER_STAT_TRANSACTION_COMPLETE, 129 BINDER_STAT_FREEZE, 130 BINDER_STAT_COUNT 131}; 132 133struct binder_stats { 134 atomic_t br[_IOC_NR(BR_CLEAR_FREEZE_NOTIFICATION_DONE) + 1]; 135 atomic_t bc[_IOC_NR(BC_FREEZE_NOTIFICATION_DONE) + 1]; 136 atomic_t obj_created[BINDER_STAT_COUNT]; 137 atomic_t obj_deleted[BINDER_STAT_COUNT]; 138}; 139 140/** 141 * struct binder_work - work enqueued on a worklist 142 * @entry: node enqueued on list 143 * @type: type of work to be performed 144 * 145 * There are separate work lists for proc, thread, and node (async). 146 */ 147struct binder_work { 148 struct list_head entry; 149 150 enum binder_work_type { 151 BINDER_WORK_TRANSACTION = 1, 152 BINDER_WORK_TRANSACTION_COMPLETE, 153 BINDER_WORK_TRANSACTION_PENDING, 154 BINDER_WORK_TRANSACTION_ONEWAY_SPAM_SUSPECT, 155 BINDER_WORK_RETURN_ERROR, 156 BINDER_WORK_NODE, 157 BINDER_WORK_DEAD_BINDER, 158 BINDER_WORK_DEAD_BINDER_AND_CLEAR, 159 BINDER_WORK_CLEAR_DEATH_NOTIFICATION, 160 BINDER_WORK_FROZEN_BINDER, 161 BINDER_WORK_CLEAR_FREEZE_NOTIFICATION, 162 } type; 163}; 164 165struct binder_error { 166 struct binder_work work; 167 uint32_t cmd; 168}; 169 170/** 171 * struct binder_node - binder node bookkeeping 172 * @debug_id: unique ID for debugging 173 * (invariant after initialized) 174 * @lock: lock for node fields 175 * @work: worklist element for node work 176 * (protected by @proc->inner_lock) 177 * @rb_node: element for proc->nodes tree 178 * (protected by @proc->inner_lock) 179 * @dead_node: element for binder_dead_nodes list 180 * (protected by binder_dead_nodes_lock) 181 * @proc: binder_proc that owns this node 182 * (invariant after initialized) 183 * @refs: list of references on this node 184 * (protected by @lock) 185 * @internal_strong_refs: used to take strong references when 186 * initiating a transaction 187 * (protected by @proc->inner_lock if @proc 188 * and by @lock) 189 * @local_weak_refs: weak user refs from local process 190 * (protected by @proc->inner_lock if @proc 191 * and by @lock) 192 * @local_strong_refs: strong user refs from local process 193 * (protected by @proc->inner_lock if @proc 194 * and by @lock) 195 * @tmp_refs: temporary kernel refs 196 * (protected by @proc->inner_lock while @proc 197 * is valid, and by binder_dead_nodes_lock 198 * if @proc is NULL. During inc/dec and node release 199 * it is also protected by @lock to provide safety 200 * as the node dies and @proc becomes NULL) 201 * @ptr: userspace pointer for node 202 * (invariant, no lock needed) 203 * @cookie: userspace cookie for node 204 * (invariant, no lock needed) 205 * @has_strong_ref: userspace notified of strong ref 206 * (protected by @proc->inner_lock if @proc 207 * and by @lock) 208 * @pending_strong_ref: userspace has acked notification of strong ref 209 * (protected by @proc->inner_lock if @proc 210 * and by @lock) 211 * @has_weak_ref: userspace notified of weak ref 212 * (protected by @proc->inner_lock if @proc 213 * and by @lock) 214 * @pending_weak_ref: userspace has acked notification of weak ref 215 * (protected by @proc->inner_lock if @proc 216 * and by @lock) 217 * @has_async_transaction: async transaction to node in progress 218 * (protected by @lock) 219 * @accept_fds: file descriptor operations supported for node 220 * (invariant after initialized) 221 * @min_priority: minimum scheduling priority 222 * (invariant after initialized) 223 * @txn_security_ctx: require sender's security context 224 * (invariant after initialized) 225 * @async_todo: list of async work items 226 * (protected by @proc->inner_lock) 227 * 228 * Bookkeeping structure for binder nodes. 229 */ 230struct binder_node { 231 int debug_id; 232 spinlock_t lock; 233 struct binder_work work; 234 union { 235 struct rb_node rb_node; 236 struct hlist_node dead_node; 237 }; 238 struct binder_proc *proc; 239 struct hlist_head refs; 240 int internal_strong_refs; 241 int local_weak_refs; 242 int local_strong_refs; 243 int tmp_refs; 244 binder_uintptr_t ptr; 245 binder_uintptr_t cookie; 246 struct { 247 /* 248 * bitfield elements protected by 249 * proc inner_lock 250 */ 251 u8 has_strong_ref:1; 252 u8 pending_strong_ref:1; 253 u8 has_weak_ref:1; 254 u8 pending_weak_ref:1; 255 }; 256 struct { 257 /* 258 * invariant after initialization 259 */ 260 u8 accept_fds:1; 261 u8 txn_security_ctx:1; 262 u8 min_priority; 263 }; 264 bool has_async_transaction; 265 struct list_head async_todo; 266}; 267 268struct binder_ref_death { 269 /** 270 * @work: worklist element for death notifications 271 * (protected by inner_lock of the proc that 272 * this ref belongs to) 273 */ 274 struct binder_work work; 275 binder_uintptr_t cookie; 276}; 277 278struct binder_ref_freeze { 279 struct binder_work work; 280 binder_uintptr_t cookie; 281 bool is_frozen:1; 282 bool sent:1; 283 bool resend:1; 284}; 285 286/** 287 * struct binder_ref_data - binder_ref counts and id 288 * @debug_id: unique ID for the ref 289 * @desc: unique userspace handle for ref 290 * @strong: strong ref count (debugging only if not locked) 291 * @weak: weak ref count (debugging only if not locked) 292 * 293 * Structure to hold ref count and ref id information. Since 294 * the actual ref can only be accessed with a lock, this structure 295 * is used to return information about the ref to callers of 296 * ref inc/dec functions. 297 */ 298struct binder_ref_data { 299 int debug_id; 300 uint32_t desc; 301 int strong; 302 int weak; 303}; 304 305/** 306 * struct binder_ref - struct to track references on nodes 307 * @data: binder_ref_data containing id, handle, and current refcounts 308 * @rb_node_desc: node for lookup by @data.desc in proc's rb_tree 309 * @rb_node_node: node for lookup by @node in proc's rb_tree 310 * @node_entry: list entry for node->refs list in target node 311 * (protected by @node->lock) 312 * @proc: binder_proc containing ref 313 * @node: binder_node of target node. When cleaning up a 314 * ref for deletion in binder_cleanup_ref, a non-NULL 315 * @node indicates the node must be freed 316 * @death: pointer to death notification (ref_death) if requested 317 * (protected by @node->lock) 318 * @freeze: pointer to freeze notification (ref_freeze) if requested 319 * (protected by @node->lock) 320 * 321 * Structure to track references from procA to target node (on procB). This 322 * structure is unsafe to access without holding @proc->outer_lock. 323 */ 324struct binder_ref { 325 /* Lookups needed: */ 326 /* node + proc => ref (transaction) */ 327 /* desc + proc => ref (transaction, inc/dec ref) */ 328 /* node => refs + procs (proc exit) */ 329 struct binder_ref_data data; 330 struct rb_node rb_node_desc; 331 struct rb_node rb_node_node; 332 struct hlist_node node_entry; 333 struct binder_proc *proc; 334 struct binder_node *node; 335 struct binder_ref_death *death; 336 struct binder_ref_freeze *freeze; 337}; 338 339/** 340 * struct binder_proc - binder process bookkeeping 341 * @proc_node: element for binder_procs list 342 * @threads: rbtree of binder_threads in this proc 343 * (protected by @inner_lock) 344 * @nodes: rbtree of binder nodes associated with 345 * this proc ordered by node->ptr 346 * (protected by @inner_lock) 347 * @refs_by_desc: rbtree of refs ordered by ref->desc 348 * (protected by @outer_lock) 349 * @refs_by_node: rbtree of refs ordered by ref->node 350 * (protected by @outer_lock) 351 * @waiting_threads: threads currently waiting for proc work 352 * (protected by @inner_lock) 353 * @pid PID of group_leader of process 354 * (invariant after initialized) 355 * @tsk task_struct for group_leader of process 356 * (invariant after initialized) 357 * @cred struct cred associated with the `struct file` 358 * in binder_open() 359 * (invariant after initialized) 360 * @deferred_work_node: element for binder_deferred_list 361 * (protected by binder_deferred_lock) 362 * @deferred_work: bitmap of deferred work to perform 363 * (protected by binder_deferred_lock) 364 * @outstanding_txns: number of transactions to be transmitted before 365 * processes in freeze_wait are woken up 366 * (protected by @inner_lock) 367 * @is_dead: process is dead and awaiting free 368 * when outstanding transactions are cleaned up 369 * (protected by @inner_lock) 370 * @is_frozen: process is frozen and unable to service 371 * binder transactions 372 * (protected by @inner_lock) 373 * @sync_recv: process received sync transactions since last frozen 374 * bit 0: received sync transaction after being frozen 375 * bit 1: new pending sync transaction during freezing 376 * (protected by @inner_lock) 377 * @async_recv: process received async transactions since last frozen 378 * (protected by @inner_lock) 379 * @freeze_wait: waitqueue of processes waiting for all outstanding 380 * transactions to be processed 381 * (protected by @inner_lock) 382 * @dmap dbitmap to manage available reference descriptors 383 * (protected by @outer_lock) 384 * @todo: list of work for this process 385 * (protected by @inner_lock) 386 * @stats: per-process binder statistics 387 * (atomics, no lock needed) 388 * @delivered_death: list of delivered death notification 389 * (protected by @inner_lock) 390 * @delivered_freeze: list of delivered freeze notification 391 * (protected by @inner_lock) 392 * @max_threads: cap on number of binder threads 393 * (protected by @inner_lock) 394 * @requested_threads: number of binder threads requested but not 395 * yet started. In current implementation, can 396 * only be 0 or 1. 397 * (protected by @inner_lock) 398 * @requested_threads_started: number binder threads started 399 * (protected by @inner_lock) 400 * @tmp_ref: temporary reference to indicate proc is in use 401 * (protected by @inner_lock) 402 * @default_priority: default scheduler priority 403 * (invariant after initialized) 404 * @debugfs_entry: debugfs node 405 * @alloc: binder allocator bookkeeping 406 * @context: binder_context for this proc 407 * (invariant after initialized) 408 * @inner_lock: can nest under outer_lock and/or node lock 409 * @outer_lock: no nesting under innor or node lock 410 * Lock order: 1) outer, 2) node, 3) inner 411 * @binderfs_entry: process-specific binderfs log file 412 * @oneway_spam_detection_enabled: process enabled oneway spam detection 413 * or not 414 * 415 * Bookkeeping structure for binder processes 416 */ 417struct binder_proc { 418 struct hlist_node proc_node; 419 struct rb_root threads; 420 struct rb_root nodes; 421 struct rb_root refs_by_desc; 422 struct rb_root refs_by_node; 423 struct list_head waiting_threads; 424 int pid; 425 struct task_struct *tsk; 426 const struct cred *cred; 427 struct hlist_node deferred_work_node; 428 int deferred_work; 429 int outstanding_txns; 430 bool is_dead; 431 bool is_frozen; 432 bool sync_recv; 433 bool async_recv; 434 wait_queue_head_t freeze_wait; 435 struct dbitmap dmap; 436 struct list_head todo; 437 struct binder_stats stats; 438 struct list_head delivered_death; 439 struct list_head delivered_freeze; 440 u32 max_threads; 441 int requested_threads; 442 int requested_threads_started; 443 int tmp_ref; 444 long default_priority; 445 struct dentry *debugfs_entry; 446 struct binder_alloc alloc; 447 struct binder_context *context; 448 spinlock_t inner_lock; 449 spinlock_t outer_lock; 450 struct dentry *binderfs_entry; 451 bool oneway_spam_detection_enabled; 452}; 453 454/** 455 * struct binder_thread - binder thread bookkeeping 456 * @proc: binder process for this thread 457 * (invariant after initialization) 458 * @rb_node: element for proc->threads rbtree 459 * (protected by @proc->inner_lock) 460 * @waiting_thread_node: element for @proc->waiting_threads list 461 * (protected by @proc->inner_lock) 462 * @pid: PID for this thread 463 * (invariant after initialization) 464 * @looper: bitmap of looping state 465 * (only accessed by this thread) 466 * @looper_needs_return: looping thread needs to exit driver 467 * (no lock needed) 468 * @transaction_stack: stack of in-progress transactions for this thread 469 * (protected by @proc->inner_lock) 470 * @todo: list of work to do for this thread 471 * (protected by @proc->inner_lock) 472 * @process_todo: whether work in @todo should be processed 473 * (protected by @proc->inner_lock) 474 * @return_error: transaction errors reported by this thread 475 * (only accessed by this thread) 476 * @reply_error: transaction errors reported by target thread 477 * (protected by @proc->inner_lock) 478 * @ee: extended error information from this thread 479 * (protected by @proc->inner_lock) 480 * @wait: wait queue for thread work 481 * @stats: per-thread statistics 482 * (atomics, no lock needed) 483 * @tmp_ref: temporary reference to indicate thread is in use 484 * (atomic since @proc->inner_lock cannot 485 * always be acquired) 486 * @is_dead: thread is dead and awaiting free 487 * when outstanding transactions are cleaned up 488 * (protected by @proc->inner_lock) 489 * 490 * Bookkeeping structure for binder threads. 491 */ 492struct binder_thread { 493 struct binder_proc *proc; 494 struct rb_node rb_node; 495 struct list_head waiting_thread_node; 496 int pid; 497 int looper; /* only modified by this thread */ 498 bool looper_need_return; /* can be written by other thread */ 499 struct binder_transaction *transaction_stack; 500 struct list_head todo; 501 bool process_todo; 502 struct binder_error return_error; 503 struct binder_error reply_error; 504 struct binder_extended_error ee; 505 wait_queue_head_t wait; 506 struct binder_stats stats; 507 atomic_t tmp_ref; 508 bool is_dead; 509}; 510 511/** 512 * struct binder_txn_fd_fixup - transaction fd fixup list element 513 * @fixup_entry: list entry 514 * @file: struct file to be associated with new fd 515 * @offset: offset in buffer data to this fixup 516 * @target_fd: fd to use by the target to install @file 517 * 518 * List element for fd fixups in a transaction. Since file 519 * descriptors need to be allocated in the context of the 520 * target process, we pass each fd to be processed in this 521 * struct. 522 */ 523struct binder_txn_fd_fixup { 524 struct list_head fixup_entry; 525 struct file *file; 526 size_t offset; 527 int target_fd; 528}; 529 530struct binder_transaction { 531 int debug_id; 532 struct binder_work work; 533 struct binder_thread *from; 534 pid_t from_pid; 535 pid_t from_tid; 536 struct binder_transaction *from_parent; 537 struct binder_proc *to_proc; 538 struct binder_thread *to_thread; 539 struct binder_transaction *to_parent; 540 unsigned is_async:1; 541 unsigned is_reply:1; 542 543 struct binder_buffer *buffer; 544 unsigned int code; 545 unsigned int flags; 546 long priority; 547 long saved_priority; 548 kuid_t sender_euid; 549 ktime_t start_time; 550 struct list_head fd_fixups; 551 binder_uintptr_t security_ctx; 552 /** 553 * @lock: protects @from, @to_proc, and @to_thread 554 * 555 * @from, @to_proc, and @to_thread can be set to NULL 556 * during thread teardown 557 */ 558 spinlock_t lock; 559}; 560 561/** 562 * struct binder_object - union of flat binder object types 563 * @hdr: generic object header 564 * @fbo: binder object (nodes and refs) 565 * @fdo: file descriptor object 566 * @bbo: binder buffer pointer 567 * @fdao: file descriptor array 568 * 569 * Used for type-independent object copies 570 */ 571struct binder_object { 572 union { 573 struct binder_object_header hdr; 574 struct flat_binder_object fbo; 575 struct binder_fd_object fdo; 576 struct binder_buffer_object bbo; 577 struct binder_fd_array_object fdao; 578 }; 579}; 580 581/** 582 * Add a binder device to binder_devices 583 * @device: the new binder device to add to the global list 584 */ 585void binder_add_device(struct binder_device *device); 586 587/** 588 * Remove a binder device to binder_devices 589 * @device: the binder device to remove from the global list 590 */ 591void binder_remove_device(struct binder_device *device); 592 593#if IS_ENABLED(CONFIG_KUNIT) 594vm_fault_t binder_vm_fault(struct vm_fault *vmf); 595#endif 596 597#endif /* _LINUX_BINDER_INTERNAL_H */
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