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