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
18 struct 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 (only used for devices requested via
28 * CONFIG_ANDROID_BINDER_DEVICES)
29 * @miscdev: information about a binder character device node
30 * @context: binder context information
31 * @binderfs_inode: This is the inode of the root dentry of the super block
32 * belonging to a binderfs mount.
33 */
34 struct binder_device {
35 struct hlist_node hlist;
36 struct miscdevice miscdev;
37 struct binder_context context;
38 struct inode *binderfs_inode;
39 refcount_t ref;
40 };
41
42 /**
43 * binderfs_mount_opts - mount options for binderfs
44 * @max: maximum number of allocatable binderfs binder devices
45 * @stats_mode: enable binder stats in binderfs.
46 */
47 struct binderfs_mount_opts {
48 int max;
49 int stats_mode;
50 };
51
52 /**
53 * binderfs_info - information about a binderfs mount
54 * @ipc_ns: The ipc namespace the binderfs mount belongs to.
55 * @control_dentry: This records the dentry of this binderfs mount
56 * binder-control device.
57 * @root_uid: uid that needs to be used when a new binder device is
58 * created.
59 * @root_gid: gid that needs to be used when a new binder device is
60 * created.
61 * @mount_opts: The mount options in use.
62 * @device_count: The current number of allocated binder devices.
63 * @proc_log_dir: Pointer to the directory dentry containing process-specific
64 * logs.
65 */
66 struct binderfs_info {
67 struct ipc_namespace *ipc_ns;
68 struct dentry *control_dentry;
69 kuid_t root_uid;
70 kgid_t root_gid;
71 struct binderfs_mount_opts mount_opts;
72 int device_count;
73 struct dentry *proc_log_dir;
74 };
75
76 extern const struct file_operations binder_fops;
77
78 extern char *binder_devices_param;
79
80 #ifdef CONFIG_ANDROID_BINDERFS
81 extern bool is_binderfs_device(const struct inode *inode);
82 extern struct dentry *binderfs_create_file(struct dentry *dir, const char *name,
83 const struct file_operations *fops,
84 void *data);
85 extern void binderfs_remove_file(struct dentry *dentry);
86 #else
is_binderfs_device(const struct inode * inode)87 static inline bool is_binderfs_device(const struct inode *inode)
88 {
89 return false;
90 }
binderfs_create_file(struct dentry * dir,const char * name,const struct file_operations * fops,void * data)91 static inline struct dentry *binderfs_create_file(struct dentry *dir,
92 const char *name,
93 const struct file_operations *fops,
94 void *data)
95 {
96 return NULL;
97 }
binderfs_remove_file(struct dentry * dentry)98 static inline void binderfs_remove_file(struct dentry *dentry) {}
99 #endif
100
101 #ifdef CONFIG_ANDROID_BINDERFS
102 extern int __init init_binderfs(void);
103 #else
init_binderfs(void)104 static inline int __init init_binderfs(void)
105 {
106 return 0;
107 }
108 #endif
109
110 struct binder_debugfs_entry {
111 const char *name;
112 umode_t mode;
113 const struct file_operations *fops;
114 void *data;
115 };
116
117 extern const struct binder_debugfs_entry binder_debugfs_entries[];
118
119 #define binder_for_each_debugfs_entry(entry) \
120 for ((entry) = binder_debugfs_entries; \
121 (entry)->name; \
122 (entry)++)
123
124 enum binder_stat_types {
125 BINDER_STAT_PROC,
126 BINDER_STAT_THREAD,
127 BINDER_STAT_NODE,
128 BINDER_STAT_REF,
129 BINDER_STAT_DEATH,
130 BINDER_STAT_TRANSACTION,
131 BINDER_STAT_TRANSACTION_COMPLETE,
132 BINDER_STAT_COUNT
133 };
134
135 struct binder_stats {
136 atomic_t br[_IOC_NR(BR_TRANSACTION_PENDING_FROZEN) + 1];
137 atomic_t bc[_IOC_NR(BC_REPLY_SG) + 1];
138 atomic_t obj_created[BINDER_STAT_COUNT];
139 atomic_t obj_deleted[BINDER_STAT_COUNT];
140 };
141
142 /**
143 * struct binder_work - work enqueued on a worklist
144 * @entry: node enqueued on list
145 * @type: type of work to be performed
146 *
147 * There are separate work lists for proc, thread, and node (async).
148 */
149 struct binder_work {
150 struct list_head entry;
151
152 enum binder_work_type {
153 BINDER_WORK_TRANSACTION = 1,
154 BINDER_WORK_TRANSACTION_COMPLETE,
155 BINDER_WORK_TRANSACTION_PENDING,
156 BINDER_WORK_TRANSACTION_ONEWAY_SPAM_SUSPECT,
157 BINDER_WORK_RETURN_ERROR,
158 BINDER_WORK_NODE,
159 BINDER_WORK_DEAD_BINDER,
160 BINDER_WORK_DEAD_BINDER_AND_CLEAR,
161 BINDER_WORK_CLEAR_DEATH_NOTIFICATION,
162 } type;
163 };
164
165 struct 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 */
230 struct 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
268 struct 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
278 /**
279 * struct binder_ref_data - binder_ref counts and id
280 * @debug_id: unique ID for the ref
281 * @desc: unique userspace handle for ref
282 * @strong: strong ref count (debugging only if not locked)
283 * @weak: weak ref count (debugging only if not locked)
284 *
285 * Structure to hold ref count and ref id information. Since
286 * the actual ref can only be accessed with a lock, this structure
287 * is used to return information about the ref to callers of
288 * ref inc/dec functions.
289 */
290 struct binder_ref_data {
291 int debug_id;
292 uint32_t desc;
293 int strong;
294 int weak;
295 };
296
297 /**
298 * struct binder_ref - struct to track references on nodes
299 * @data: binder_ref_data containing id, handle, and current refcounts
300 * @rb_node_desc: node for lookup by @data.desc in proc's rb_tree
301 * @rb_node_node: node for lookup by @node in proc's rb_tree
302 * @node_entry: list entry for node->refs list in target node
303 * (protected by @node->lock)
304 * @proc: binder_proc containing ref
305 * @node: binder_node of target node. When cleaning up a
306 * ref for deletion in binder_cleanup_ref, a non-NULL
307 * @node indicates the node must be freed
308 * @death: pointer to death notification (ref_death) if requested
309 * (protected by @node->lock)
310 *
311 * Structure to track references from procA to target node (on procB). This
312 * structure is unsafe to access without holding @proc->outer_lock.
313 */
314 struct binder_ref {
315 /* Lookups needed: */
316 /* node + proc => ref (transaction) */
317 /* desc + proc => ref (transaction, inc/dec ref) */
318 /* node => refs + procs (proc exit) */
319 struct binder_ref_data data;
320 struct rb_node rb_node_desc;
321 struct rb_node rb_node_node;
322 struct hlist_node node_entry;
323 struct binder_proc *proc;
324 struct binder_node *node;
325 struct binder_ref_death *death;
326 };
327
328 /**
329 * struct binder_proc - binder process bookkeeping
330 * @proc_node: element for binder_procs list
331 * @threads: rbtree of binder_threads in this proc
332 * (protected by @inner_lock)
333 * @nodes: rbtree of binder nodes associated with
334 * this proc ordered by node->ptr
335 * (protected by @inner_lock)
336 * @refs_by_desc: rbtree of refs ordered by ref->desc
337 * (protected by @outer_lock)
338 * @refs_by_node: rbtree of refs ordered by ref->node
339 * (protected by @outer_lock)
340 * @waiting_threads: threads currently waiting for proc work
341 * (protected by @inner_lock)
342 * @pid PID of group_leader of process
343 * (invariant after initialized)
344 * @tsk task_struct for group_leader of process
345 * (invariant after initialized)
346 * @cred struct cred associated with the `struct file`
347 * in binder_open()
348 * (invariant after initialized)
349 * @deferred_work_node: element for binder_deferred_list
350 * (protected by binder_deferred_lock)
351 * @deferred_work: bitmap of deferred work to perform
352 * (protected by binder_deferred_lock)
353 * @outstanding_txns: number of transactions to be transmitted before
354 * processes in freeze_wait are woken up
355 * (protected by @inner_lock)
356 * @is_dead: process is dead and awaiting free
357 * when outstanding transactions are cleaned up
358 * (protected by @inner_lock)
359 * @is_frozen: process is frozen and unable to service
360 * binder transactions
361 * (protected by @inner_lock)
362 * @sync_recv: process received sync transactions since last frozen
363 * bit 0: received sync transaction after being frozen
364 * bit 1: new pending sync transaction during freezing
365 * (protected by @inner_lock)
366 * @async_recv: process received async transactions since last frozen
367 * (protected by @inner_lock)
368 * @freeze_wait: waitqueue of processes waiting for all outstanding
369 * transactions to be processed
370 * (protected by @inner_lock)
371 * @todo: list of work for this process
372 * (protected by @inner_lock)
373 * @stats: per-process binder statistics
374 * (atomics, no lock needed)
375 * @delivered_death: list of delivered death notification
376 * (protected by @inner_lock)
377 * @max_threads: cap on number of binder threads
378 * (protected by @inner_lock)
379 * @requested_threads: number of binder threads requested but not
380 * yet started. In current implementation, can
381 * only be 0 or 1.
382 * (protected by @inner_lock)
383 * @requested_threads_started: number binder threads started
384 * (protected by @inner_lock)
385 * @tmp_ref: temporary reference to indicate proc is in use
386 * (protected by @inner_lock)
387 * @default_priority: default scheduler priority
388 * (invariant after initialized)
389 * @debugfs_entry: debugfs node
390 * @alloc: binder allocator bookkeeping
391 * @context: binder_context for this proc
392 * (invariant after initialized)
393 * @inner_lock: can nest under outer_lock and/or node lock
394 * @outer_lock: no nesting under innor or node lock
395 * Lock order: 1) outer, 2) node, 3) inner
396 * @binderfs_entry: process-specific binderfs log file
397 * @oneway_spam_detection_enabled: process enabled oneway spam detection
398 * or not
399 *
400 * Bookkeeping structure for binder processes
401 */
402 struct binder_proc {
403 struct hlist_node proc_node;
404 struct rb_root threads;
405 struct rb_root nodes;
406 struct rb_root refs_by_desc;
407 struct rb_root refs_by_node;
408 struct list_head waiting_threads;
409 int pid;
410 struct task_struct *tsk;
411 const struct cred *cred;
412 struct hlist_node deferred_work_node;
413 int deferred_work;
414 int outstanding_txns;
415 bool is_dead;
416 bool is_frozen;
417 bool sync_recv;
418 bool async_recv;
419 wait_queue_head_t freeze_wait;
420
421 struct list_head todo;
422 struct binder_stats stats;
423 struct list_head delivered_death;
424 int max_threads;
425 int requested_threads;
426 int requested_threads_started;
427 int tmp_ref;
428 long default_priority;
429 struct dentry *debugfs_entry;
430 struct binder_alloc alloc;
431 struct binder_context *context;
432 spinlock_t inner_lock;
433 spinlock_t outer_lock;
434 struct dentry *binderfs_entry;
435 bool oneway_spam_detection_enabled;
436 };
437
438 /**
439 * struct binder_thread - binder thread bookkeeping
440 * @proc: binder process for this thread
441 * (invariant after initialization)
442 * @rb_node: element for proc->threads rbtree
443 * (protected by @proc->inner_lock)
444 * @waiting_thread_node: element for @proc->waiting_threads list
445 * (protected by @proc->inner_lock)
446 * @pid: PID for this thread
447 * (invariant after initialization)
448 * @looper: bitmap of looping state
449 * (only accessed by this thread)
450 * @looper_needs_return: looping thread needs to exit driver
451 * (no lock needed)
452 * @transaction_stack: stack of in-progress transactions for this thread
453 * (protected by @proc->inner_lock)
454 * @todo: list of work to do for this thread
455 * (protected by @proc->inner_lock)
456 * @process_todo: whether work in @todo should be processed
457 * (protected by @proc->inner_lock)
458 * @return_error: transaction errors reported by this thread
459 * (only accessed by this thread)
460 * @reply_error: transaction errors reported by target thread
461 * (protected by @proc->inner_lock)
462 * @ee: extended error information from this thread
463 * (protected by @proc->inner_lock)
464 * @wait: wait queue for thread work
465 * @stats: per-thread statistics
466 * (atomics, no lock needed)
467 * @tmp_ref: temporary reference to indicate thread is in use
468 * (atomic since @proc->inner_lock cannot
469 * always be acquired)
470 * @is_dead: thread is dead and awaiting free
471 * when outstanding transactions are cleaned up
472 * (protected by @proc->inner_lock)
473 *
474 * Bookkeeping structure for binder threads.
475 */
476 struct binder_thread {
477 struct binder_proc *proc;
478 struct rb_node rb_node;
479 struct list_head waiting_thread_node;
480 int pid;
481 int looper; /* only modified by this thread */
482 bool looper_need_return; /* can be written by other thread */
483 struct binder_transaction *transaction_stack;
484 struct list_head todo;
485 bool process_todo;
486 struct binder_error return_error;
487 struct binder_error reply_error;
488 struct binder_extended_error ee;
489 wait_queue_head_t wait;
490 struct binder_stats stats;
491 atomic_t tmp_ref;
492 bool is_dead;
493 };
494
495 /**
496 * struct binder_txn_fd_fixup - transaction fd fixup list element
497 * @fixup_entry: list entry
498 * @file: struct file to be associated with new fd
499 * @offset: offset in buffer data to this fixup
500 * @target_fd: fd to use by the target to install @file
501 *
502 * List element for fd fixups in a transaction. Since file
503 * descriptors need to be allocated in the context of the
504 * target process, we pass each fd to be processed in this
505 * struct.
506 */
507 struct binder_txn_fd_fixup {
508 struct list_head fixup_entry;
509 struct file *file;
510 size_t offset;
511 int target_fd;
512 };
513
514 struct binder_transaction {
515 int debug_id;
516 struct binder_work work;
517 struct binder_thread *from;
518 pid_t from_pid;
519 pid_t from_tid;
520 struct binder_transaction *from_parent;
521 struct binder_proc *to_proc;
522 struct binder_thread *to_thread;
523 struct binder_transaction *to_parent;
524 unsigned need_reply:1;
525 /* unsigned is_dead:1; */ /* not used at the moment */
526
527 struct binder_buffer *buffer;
528 unsigned int code;
529 unsigned int flags;
530 long priority;
531 long saved_priority;
532 kuid_t sender_euid;
533 ktime_t start_time;
534 struct list_head fd_fixups;
535 binder_uintptr_t security_ctx;
536 /**
537 * @lock: protects @from, @to_proc, and @to_thread
538 *
539 * @from, @to_proc, and @to_thread can be set to NULL
540 * during thread teardown
541 */
542 spinlock_t lock;
543 };
544
545 /**
546 * struct binder_object - union of flat binder object types
547 * @hdr: generic object header
548 * @fbo: binder object (nodes and refs)
549 * @fdo: file descriptor object
550 * @bbo: binder buffer pointer
551 * @fdao: file descriptor array
552 *
553 * Used for type-independent object copies
554 */
555 struct binder_object {
556 union {
557 struct binder_object_header hdr;
558 struct flat_binder_object fbo;
559 struct binder_fd_object fdo;
560 struct binder_buffer_object bbo;
561 struct binder_fd_array_object fdao;
562 };
563 };
564
565 #endif /* _LINUX_BINDER_INTERNAL_H */
566
