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
87 static inline bool is_binderfs_device(const struct inode *inode)
88 {
89 	return false;
90 }
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 }
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
104 static inline int __init init_binderfs(void)
105 {
106 	return 0;
107 }
108 #endif
109 
110 int binder_stats_show(struct seq_file *m, void *unused);
111 DEFINE_SHOW_ATTRIBUTE(binder_stats);
112 
113 int binder_state_show(struct seq_file *m, void *unused);
114 DEFINE_SHOW_ATTRIBUTE(binder_state);
115 
116 int binder_transactions_show(struct seq_file *m, void *unused);
117 DEFINE_SHOW_ATTRIBUTE(binder_transactions);
118 
119 int binder_transaction_log_show(struct seq_file *m, void *unused);
120 DEFINE_SHOW_ATTRIBUTE(binder_transaction_log);
121 
122 struct binder_transaction_log_entry {
123 	int debug_id;
124 	int debug_id_done;
125 	int call_type;
126 	int from_proc;
127 	int from_thread;
128 	int target_handle;
129 	int to_proc;
130 	int to_thread;
131 	int to_node;
132 	int data_size;
133 	int offsets_size;
134 	int return_error_line;
135 	uint32_t return_error;
136 	uint32_t return_error_param;
137 	char context_name[BINDERFS_MAX_NAME + 1];
138 };
139 
140 struct binder_transaction_log {
141 	atomic_t cur;
142 	bool full;
143 	struct binder_transaction_log_entry entry[32];
144 };
145 
146 enum binder_stat_types {
147 	BINDER_STAT_PROC,
148 	BINDER_STAT_THREAD,
149 	BINDER_STAT_NODE,
150 	BINDER_STAT_REF,
151 	BINDER_STAT_DEATH,
152 	BINDER_STAT_TRANSACTION,
153 	BINDER_STAT_TRANSACTION_COMPLETE,
154 	BINDER_STAT_COUNT
155 };
156 
157 struct binder_stats {
158 	atomic_t br[_IOC_NR(BR_ONEWAY_SPAM_SUSPECT) + 1];
159 	atomic_t bc[_IOC_NR(BC_REPLY_SG) + 1];
160 	atomic_t obj_created[BINDER_STAT_COUNT];
161 	atomic_t obj_deleted[BINDER_STAT_COUNT];
162 };
163 
164 /**
165  * struct binder_work - work enqueued on a worklist
166  * @entry:             node enqueued on list
167  * @type:              type of work to be performed
168  *
169  * There are separate work lists for proc, thread, and node (async).
170  */
171 struct binder_work {
172 	struct list_head entry;
173 
174 	enum binder_work_type {
175 		BINDER_WORK_TRANSACTION = 1,
176 		BINDER_WORK_TRANSACTION_COMPLETE,
177 		BINDER_WORK_TRANSACTION_ONEWAY_SPAM_SUSPECT,
178 		BINDER_WORK_RETURN_ERROR,
179 		BINDER_WORK_NODE,
180 		BINDER_WORK_DEAD_BINDER,
181 		BINDER_WORK_DEAD_BINDER_AND_CLEAR,
182 		BINDER_WORK_CLEAR_DEATH_NOTIFICATION,
183 	} type;
184 };
185 
186 struct binder_error {
187 	struct binder_work work;
188 	uint32_t cmd;
189 };
190 
191 /**
192  * struct binder_node - binder node bookkeeping
193  * @debug_id:             unique ID for debugging
194  *                        (invariant after initialized)
195  * @lock:                 lock for node fields
196  * @work:                 worklist element for node work
197  *                        (protected by @proc->inner_lock)
198  * @rb_node:              element for proc->nodes tree
199  *                        (protected by @proc->inner_lock)
200  * @dead_node:            element for binder_dead_nodes list
201  *                        (protected by binder_dead_nodes_lock)
202  * @proc:                 binder_proc that owns this node
203  *                        (invariant after initialized)
204  * @refs:                 list of references on this node
205  *                        (protected by @lock)
206  * @internal_strong_refs: used to take strong references when
207  *                        initiating a transaction
208  *                        (protected by @proc->inner_lock if @proc
209  *                        and by @lock)
210  * @local_weak_refs:      weak user refs from local process
211  *                        (protected by @proc->inner_lock if @proc
212  *                        and by @lock)
213  * @local_strong_refs:    strong user refs from local process
214  *                        (protected by @proc->inner_lock if @proc
215  *                        and by @lock)
216  * @tmp_refs:             temporary kernel refs
217  *                        (protected by @proc->inner_lock while @proc
218  *                        is valid, and by binder_dead_nodes_lock
219  *                        if @proc is NULL. During inc/dec and node release
220  *                        it is also protected by @lock to provide safety
221  *                        as the node dies and @proc becomes NULL)
222  * @ptr:                  userspace pointer for node
223  *                        (invariant, no lock needed)
224  * @cookie:               userspace cookie for node
225  *                        (invariant, no lock needed)
226  * @has_strong_ref:       userspace notified of strong ref
227  *                        (protected by @proc->inner_lock if @proc
228  *                        and by @lock)
229  * @pending_strong_ref:   userspace has acked notification of strong ref
230  *                        (protected by @proc->inner_lock if @proc
231  *                        and by @lock)
232  * @has_weak_ref:         userspace notified of weak ref
233  *                        (protected by @proc->inner_lock if @proc
234  *                        and by @lock)
235  * @pending_weak_ref:     userspace has acked notification of weak ref
236  *                        (protected by @proc->inner_lock if @proc
237  *                        and by @lock)
238  * @has_async_transaction: async transaction to node in progress
239  *                        (protected by @lock)
240  * @accept_fds:           file descriptor operations supported for node
241  *                        (invariant after initialized)
242  * @min_priority:         minimum scheduling priority
243  *                        (invariant after initialized)
244  * @txn_security_ctx:     require sender's security context
245  *                        (invariant after initialized)
246  * @async_todo:           list of async work items
247  *                        (protected by @proc->inner_lock)
248  *
249  * Bookkeeping structure for binder nodes.
250  */
251 struct binder_node {
252 	int debug_id;
253 	spinlock_t lock;
254 	struct binder_work work;
255 	union {
256 		struct rb_node rb_node;
257 		struct hlist_node dead_node;
258 	};
259 	struct binder_proc *proc;
260 	struct hlist_head refs;
261 	int internal_strong_refs;
262 	int local_weak_refs;
263 	int local_strong_refs;
264 	int tmp_refs;
265 	binder_uintptr_t ptr;
266 	binder_uintptr_t cookie;
267 	struct {
268 		/*
269 		 * bitfield elements protected by
270 		 * proc inner_lock
271 		 */
272 		u8 has_strong_ref:1;
273 		u8 pending_strong_ref:1;
274 		u8 has_weak_ref:1;
275 		u8 pending_weak_ref:1;
276 	};
277 	struct {
278 		/*
279 		 * invariant after initialization
280 		 */
281 		u8 accept_fds:1;
282 		u8 txn_security_ctx:1;
283 		u8 min_priority;
284 	};
285 	bool has_async_transaction;
286 	struct list_head async_todo;
287 };
288 
289 struct binder_ref_death {
290 	/**
291 	 * @work: worklist element for death notifications
292 	 *        (protected by inner_lock of the proc that
293 	 *        this ref belongs to)
294 	 */
295 	struct binder_work work;
296 	binder_uintptr_t cookie;
297 };
298 
299 /**
300  * struct binder_ref_data - binder_ref counts and id
301  * @debug_id:        unique ID for the ref
302  * @desc:            unique userspace handle for ref
303  * @strong:          strong ref count (debugging only if not locked)
304  * @weak:            weak ref count (debugging only if not locked)
305  *
306  * Structure to hold ref count and ref id information. Since
307  * the actual ref can only be accessed with a lock, this structure
308  * is used to return information about the ref to callers of
309  * ref inc/dec functions.
310  */
311 struct binder_ref_data {
312 	int debug_id;
313 	uint32_t desc;
314 	int strong;
315 	int weak;
316 };
317 
318 /**
319  * struct binder_ref - struct to track references on nodes
320  * @data:        binder_ref_data containing id, handle, and current refcounts
321  * @rb_node_desc: node for lookup by @data.desc in proc's rb_tree
322  * @rb_node_node: node for lookup by @node in proc's rb_tree
323  * @node_entry:  list entry for node->refs list in target node
324  *               (protected by @node->lock)
325  * @proc:        binder_proc containing ref
326  * @node:        binder_node of target node. When cleaning up a
327  *               ref for deletion in binder_cleanup_ref, a non-NULL
328  *               @node indicates the node must be freed
329  * @death:       pointer to death notification (ref_death) if requested
330  *               (protected by @node->lock)
331  *
332  * Structure to track references from procA to target node (on procB). This
333  * structure is unsafe to access without holding @proc->outer_lock.
334  */
335 struct binder_ref {
336 	/* Lookups needed: */
337 	/*   node + proc => ref (transaction) */
338 	/*   desc + proc => ref (transaction, inc/dec ref) */
339 	/*   node => refs + procs (proc exit) */
340 	struct binder_ref_data data;
341 	struct rb_node rb_node_desc;
342 	struct rb_node rb_node_node;
343 	struct hlist_node node_entry;
344 	struct binder_proc *proc;
345 	struct binder_node *node;
346 	struct binder_ref_death *death;
347 };
348 
349 /**
350  * struct binder_proc - binder process bookkeeping
351  * @proc_node:            element for binder_procs list
352  * @threads:              rbtree of binder_threads in this proc
353  *                        (protected by @inner_lock)
354  * @nodes:                rbtree of binder nodes associated with
355  *                        this proc ordered by node->ptr
356  *                        (protected by @inner_lock)
357  * @refs_by_desc:         rbtree of refs ordered by ref->desc
358  *                        (protected by @outer_lock)
359  * @refs_by_node:         rbtree of refs ordered by ref->node
360  *                        (protected by @outer_lock)
361  * @waiting_threads:      threads currently waiting for proc work
362  *                        (protected by @inner_lock)
363  * @pid                   PID of group_leader of process
364  *                        (invariant after initialized)
365  * @tsk                   task_struct for group_leader of process
366  *                        (invariant after initialized)
367  * @cred                  struct cred associated with the `struct file`
368  *                        in binder_open()
369  *                        (invariant after initialized)
370  * @deferred_work_node:   element for binder_deferred_list
371  *                        (protected by binder_deferred_lock)
372  * @deferred_work:        bitmap of deferred work to perform
373  *                        (protected by binder_deferred_lock)
374  * @outstanding_txns:     number of transactions to be transmitted before
375  *                        processes in freeze_wait are woken up
376  *                        (protected by @inner_lock)
377  * @is_dead:              process is dead and awaiting free
378  *                        when outstanding transactions are cleaned up
379  *                        (protected by @inner_lock)
380  * @is_frozen:            process is frozen and unable to service
381  *                        binder transactions
382  *                        (protected by @inner_lock)
383  * @sync_recv:            process received sync transactions since last frozen
384  *                        bit 0: received sync transaction after being frozen
385  *                        bit 1: new pending sync transaction during freezing
386  *                        (protected by @inner_lock)
387  * @async_recv:           process received async transactions since last frozen
388  *                        (protected by @inner_lock)
389  * @freeze_wait:          waitqueue of processes waiting for all outstanding
390  *                        transactions to be processed
391  *                        (protected by @inner_lock)
392  * @todo:                 list of work for this process
393  *                        (protected by @inner_lock)
394  * @stats:                per-process binder statistics
395  *                        (atomics, no lock needed)
396  * @delivered_death:      list of delivered death notification
397  *                        (protected by @inner_lock)
398  * @max_threads:          cap on number of binder threads
399  *                        (protected by @inner_lock)
400  * @requested_threads:    number of binder threads requested but not
401  *                        yet started. In current implementation, can
402  *                        only be 0 or 1.
403  *                        (protected by @inner_lock)
404  * @requested_threads_started: number binder threads started
405  *                        (protected by @inner_lock)
406  * @tmp_ref:              temporary reference to indicate proc is in use
407  *                        (protected by @inner_lock)
408  * @default_priority:     default scheduler priority
409  *                        (invariant after initialized)
410  * @debugfs_entry:        debugfs node
411  * @alloc:                binder allocator bookkeeping
412  * @context:              binder_context for this proc
413  *                        (invariant after initialized)
414  * @inner_lock:           can nest under outer_lock and/or node lock
415  * @outer_lock:           no nesting under innor or node lock
416  *                        Lock order: 1) outer, 2) node, 3) inner
417  * @binderfs_entry:       process-specific binderfs log file
418  * @oneway_spam_detection_enabled: process enabled oneway spam detection
419  *                        or not
420  *
421  * Bookkeeping structure for binder processes
422  */
423 struct binder_proc {
424 	struct hlist_node proc_node;
425 	struct rb_root threads;
426 	struct rb_root nodes;
427 	struct rb_root refs_by_desc;
428 	struct rb_root refs_by_node;
429 	struct list_head waiting_threads;
430 	int pid;
431 	struct task_struct *tsk;
432 	const struct cred *cred;
433 	struct hlist_node deferred_work_node;
434 	int deferred_work;
435 	int outstanding_txns;
436 	bool is_dead;
437 	bool is_frozen;
438 	bool sync_recv;
439 	bool async_recv;
440 	wait_queue_head_t freeze_wait;
441 
442 	struct list_head todo;
443 	struct binder_stats stats;
444 	struct list_head delivered_death;
445 	int max_threads;
446 	int requested_threads;
447 	int requested_threads_started;
448 	int tmp_ref;
449 	long default_priority;
450 	struct dentry *debugfs_entry;
451 	struct binder_alloc alloc;
452 	struct binder_context *context;
453 	spinlock_t inner_lock;
454 	spinlock_t outer_lock;
455 	struct dentry *binderfs_entry;
456 	bool oneway_spam_detection_enabled;
457 };
458 
459 /**
460  * struct binder_thread - binder thread bookkeeping
461  * @proc:                 binder process for this thread
462  *                        (invariant after initialization)
463  * @rb_node:              element for proc->threads rbtree
464  *                        (protected by @proc->inner_lock)
465  * @waiting_thread_node:  element for @proc->waiting_threads list
466  *                        (protected by @proc->inner_lock)
467  * @pid:                  PID for this thread
468  *                        (invariant after initialization)
469  * @looper:               bitmap of looping state
470  *                        (only accessed by this thread)
471  * @looper_needs_return:  looping thread needs to exit driver
472  *                        (no lock needed)
473  * @transaction_stack:    stack of in-progress transactions for this thread
474  *                        (protected by @proc->inner_lock)
475  * @todo:                 list of work to do for this thread
476  *                        (protected by @proc->inner_lock)
477  * @process_todo:         whether work in @todo should be processed
478  *                        (protected by @proc->inner_lock)
479  * @return_error:         transaction errors reported by this thread
480  *                        (only accessed by this thread)
481  * @reply_error:          transaction errors reported by target thread
482  *                        (protected by @proc->inner_lock)
483  * @wait:                 wait queue for thread work
484  * @stats:                per-thread statistics
485  *                        (atomics, no lock needed)
486  * @tmp_ref:              temporary reference to indicate thread is in use
487  *                        (atomic since @proc->inner_lock cannot
488  *                        always be acquired)
489  * @is_dead:              thread is dead and awaiting free
490  *                        when outstanding transactions are cleaned up
491  *                        (protected by @proc->inner_lock)
492  *
493  * Bookkeeping structure for binder threads.
494  */
495 struct binder_thread {
496 	struct binder_proc *proc;
497 	struct rb_node rb_node;
498 	struct list_head waiting_thread_node;
499 	int pid;
500 	int looper;              /* only modified by this thread */
501 	bool looper_need_return; /* can be written by other thread */
502 	struct binder_transaction *transaction_stack;
503 	struct list_head todo;
504 	bool process_todo;
505 	struct binder_error return_error;
506 	struct binder_error reply_error;
507 	wait_queue_head_t wait;
508 	struct binder_stats stats;
509 	atomic_t tmp_ref;
510 	bool is_dead;
511 };
512 
513 /**
514  * struct binder_txn_fd_fixup - transaction fd fixup list element
515  * @fixup_entry:          list entry
516  * @file:                 struct file to be associated with new fd
517  * @offset:               offset in buffer data to this fixup
518  *
519  * List element for fd fixups in a transaction. Since file
520  * descriptors need to be allocated in the context of the
521  * target process, we pass each fd to be processed in this
522  * struct.
523  */
524 struct binder_txn_fd_fixup {
525 	struct list_head fixup_entry;
526 	struct file *file;
527 	size_t offset;
528 };
529 
530 struct binder_transaction {
531 	int debug_id;
532 	struct binder_work work;
533 	struct binder_thread *from;
534 	struct binder_transaction *from_parent;
535 	struct binder_proc *to_proc;
536 	struct binder_thread *to_thread;
537 	struct binder_transaction *to_parent;
538 	unsigned need_reply:1;
539 	/* unsigned is_dead:1; */       /* not used at the moment */
540 
541 	struct binder_buffer *buffer;
542 	unsigned int    code;
543 	unsigned int    flags;
544 	long    priority;
545 	long    saved_priority;
546 	kuid_t  sender_euid;
547 	struct list_head fd_fixups;
548 	binder_uintptr_t security_ctx;
549 	/**
550 	 * @lock:  protects @from, @to_proc, and @to_thread
551 	 *
552 	 * @from, @to_proc, and @to_thread can be set to NULL
553 	 * during thread teardown
554 	 */
555 	spinlock_t lock;
556 };
557 
558 /**
559  * struct binder_object - union of flat binder object types
560  * @hdr:   generic object header
561  * @fbo:   binder object (nodes and refs)
562  * @fdo:   file descriptor object
563  * @bbo:   binder buffer pointer
564  * @fdao:  file descriptor array
565  *
566  * Used for type-independent object copies
567  */
568 struct binder_object {
569 	union {
570 		struct binder_object_header hdr;
571 		struct flat_binder_object fbo;
572 		struct binder_fd_object fdo;
573 		struct binder_buffer_object bbo;
574 		struct binder_fd_array_object fdao;
575 	};
576 };
577 
578 extern struct binder_transaction_log binder_transaction_log;
579 extern struct binder_transaction_log binder_transaction_log_failed;
580 #endif /* _LINUX_BINDER_INTERNAL_H */
581