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/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_FAILED_REPLY) + 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_RETURN_ERROR,
 178                 BINDER_WORK_NODE,
 179                 BINDER_WORK_DEAD_BINDER,
 180                 BINDER_WORK_DEAD_BINDER_AND_CLEAR,
 181                 BINDER_WORK_CLEAR_DEATH_NOTIFICATION,
 182         } type;
 183 };
 184
 185 struct binder_error {
 186         struct binder_work work;
 187         uint32_t cmd;
 188 };
 189
 190 /**
 191  * struct binder_node - binder node bookkeeping
 192  * @debug_id:             unique ID for debugging
 193  *                        (invariant after initialized)
 194  * @lock:                 lock for node fields
 195  * @work:                 worklist element for node work
 196  *                        (protected by @proc->inner_lock)
 197  * @rb_node:              element for proc->nodes tree
 198  *                        (protected by @proc->inner_lock)
 199  * @dead_node:            element for binder_dead_nodes list
 200  *                        (protected by binder_dead_nodes_lock)
 201  * @proc:                 binder_proc that owns this node
 202  *                        (invariant after initialized)
 203  * @refs:                 list of references on this node
 204  *                        (protected by @lock)
 205  * @internal_strong_refs: used to take strong references when
 206  *                        initiating a transaction
 207  *                        (protected by @proc->inner_lock if @proc
 208  *                        and by @lock)
 209  * @local_weak_refs:      weak user refs from local process
 210  *                        (protected by @proc->inner_lock if @proc
 211  *                        and by @lock)
 212  * @local_strong_refs:    strong user refs from local process
 213  *                        (protected by @proc->inner_lock if @proc
 214  *                        and by @lock)
 215  * @tmp_refs:             temporary kernel refs
 216  *                        (protected by @proc->inner_lock while @proc
 217  *                        is valid, and by binder_dead_nodes_lock
 218  *                        if @proc is NULL. During inc/dec and node release
 219  *                        it is also protected by @lock to provide safety
 220  *                        as the node dies and @proc becomes NULL)
 221  * @ptr:                  userspace pointer for node
 222  *                        (invariant, no lock needed)
 223  * @cookie:               userspace cookie for node
 224  *                        (invariant, no lock needed)
 225  * @has_strong_ref:       userspace notified of strong ref
 226  *                        (protected by @proc->inner_lock if @proc
 227  *                        and by @lock)
 228  * @pending_strong_ref:   userspace has acked notification of strong ref
 229  *                        (protected by @proc->inner_lock if @proc
 230  *                        and by @lock)
 231  * @has_weak_ref:         userspace notified of weak ref
 232  *                        (protected by @proc->inner_lock if @proc
 233  *                        and by @lock)
 234  * @pending_weak_ref:     userspace has acked notification of weak ref
 235  *                        (protected by @proc->inner_lock if @proc
 236  *                        and by @lock)
 237  * @has_async_transaction: async transaction to node in progress
 238  *                        (protected by @lock)
 239  * @accept_fds:           file descriptor operations supported for node
 240  *                        (invariant after initialized)
 241  * @min_priority:         minimum scheduling priority
 242  *                        (invariant after initialized)
 243  * @txn_security_ctx:     require sender's security context
 244  *                        (invariant after initialized)
 245  * @async_todo:           list of async work items
 246  *                        (protected by @proc->inner_lock)
 247  *
 248  * Bookkeeping structure for binder nodes.
 249  */
 250 struct binder_node {
 251         int debug_id;
 252         spinlock_t lock;
 253         struct binder_work work;
 254         union {
 255                 struct rb_node rb_node;
 256                 struct hlist_node dead_node;
 257         };
 258         struct binder_proc *proc;
 259         struct hlist_head refs;
 260         int internal_strong_refs;
 261         int local_weak_refs;
 262         int local_strong_refs;
 263         int tmp_refs;
 264         binder_uintptr_t ptr;
 265         binder_uintptr_t cookie;
 266         struct {
 267                 /*
 268                  * bitfield elements protected by
 269                  * proc inner_lock
 270                  */
 271                 u8 has_strong_ref:1;
 272                 u8 pending_strong_ref:1;
 273                 u8 has_weak_ref:1;
 274                 u8 pending_weak_ref:1;
 275         };
 276         struct {
 277                 /*
 278                  * invariant after initialization
 279                  */
 280                 u8 accept_fds:1;
 281                 u8 txn_security_ctx:1;
 282                 u8 min_priority;
 283         };
 284         bool has_async_transaction;
 285         struct list_head async_todo;
 286 };
 287
 288 struct binder_ref_death {
 289         /**
 290          * @work: worklist element for death notifications
 291          *        (protected by inner_lock of the proc that
 292          *        this ref belongs to)
 293          */
 294         struct binder_work work;
 295         binder_uintptr_t cookie;
 296 };
 297
 298 /**
 299  * struct binder_ref_data - binder_ref counts and id
 300  * @debug_id:        unique ID for the ref
 301  * @desc:            unique userspace handle for ref
 302  * @strong:          strong ref count (debugging only if not locked)
 303  * @weak:            weak ref count (debugging only if not locked)
 304  *
 305  * Structure to hold ref count and ref id information. Since
 306  * the actual ref can only be accessed with a lock, this structure
 307  * is used to return information about the ref to callers of
 308  * ref inc/dec functions.
 309  */
 310 struct binder_ref_data {
 311         int debug_id;
 312         uint32_t desc;
 313         int strong;
 314         int weak;
 315 };
 316
 317 /**
 318  * struct binder_ref - struct to track references on nodes
 319  * @data:        binder_ref_data containing id, handle, and current refcounts
 320  * @rb_node_desc: node for lookup by @data.desc in proc's rb_tree
 321  * @rb_node_node: node for lookup by @node in proc's rb_tree
 322  * @node_entry:  list entry for node->refs list in target node
 323  *               (protected by @node->lock)
 324  * @proc:        binder_proc containing ref
 325  * @node:        binder_node of target node. When cleaning up a
 326  *               ref for deletion in binder_cleanup_ref, a non-NULL
 327  *               @node indicates the node must be freed
 328  * @death:       pointer to death notification (ref_death) if requested
 329  *               (protected by @node->lock)
 330  *
 331  * Structure to track references from procA to target node (on procB). This
 332  * structure is unsafe to access without holding @proc->outer_lock.
 333  */
 334 struct binder_ref {
 335         /* Lookups needed: */
 336         /*   node + proc => ref (transaction) */
 337         /*   desc + proc => ref (transaction, inc/dec ref) */
 338         /*   node => refs + procs (proc exit) */
 339         struct binder_ref_data data;
 340         struct rb_node rb_node_desc;
 341         struct rb_node rb_node_node;
 342         struct hlist_node node_entry;
 343         struct binder_proc *proc;
 344         struct binder_node *node;
 345         struct binder_ref_death *death;
 346 };
 347
 348 /**
 349  * struct binder_proc - binder process bookkeeping
 350  * @proc_node:            element for binder_procs list
 351  * @threads:              rbtree of binder_threads in this proc
 352  *                        (protected by @inner_lock)
 353  * @nodes:                rbtree of binder nodes associated with
 354  *                        this proc ordered by node->ptr
 355  *                        (protected by @inner_lock)
 356  * @refs_by_desc:         rbtree of refs ordered by ref->desc
 357  *                        (protected by @outer_lock)
 358  * @refs_by_node:         rbtree of refs ordered by ref->node
 359  *                        (protected by @outer_lock)
 360  * @waiting_threads:      threads currently waiting for proc work
 361  *                        (protected by @inner_lock)
 362  * @pid                   PID of group_leader of process
 363  *                        (invariant after initialized)
 364  * @tsk                   task_struct for group_leader of process
 365  *                        (invariant after initialized)
 366  * @deferred_work_node:   element for binder_deferred_list
 367  *                        (protected by binder_deferred_lock)
 368  * @deferred_work:        bitmap of deferred work to perform
 369  *                        (protected by binder_deferred_lock)
 370  * @is_dead:              process is dead and awaiting free
 371  *                        when outstanding transactions are cleaned up
 372  *                        (protected by @inner_lock)
 373  * @todo:                 list of work for this process
 374  *                        (protected by @inner_lock)
 375  * @stats:                per-process binder statistics
 376  *                        (atomics, no lock needed)
 377  * @delivered_death:      list of delivered death notification
 378  *                        (protected by @inner_lock)
 379  * @max_threads:          cap on number of binder threads
 380  *                        (protected by @inner_lock)
 381  * @requested_threads:    number of binder threads requested but not
 382  *                        yet started. In current implementation, can
 383  *                        only be 0 or 1.
 384  *                        (protected by @inner_lock)
 385  * @requested_threads_started: number binder threads started
 386  *                        (protected by @inner_lock)
 387  * @tmp_ref:              temporary reference to indicate proc is in use
 388  *                        (protected by @inner_lock)
 389  * @default_priority:     default scheduler priority
 390  *                        (invariant after initialized)
 391  * @debugfs_entry:        debugfs node
 392  * @alloc:                binder allocator bookkeeping
 393  * @context:              binder_context for this proc
 394  *                        (invariant after initialized)
 395  * @inner_lock:           can nest under outer_lock and/or node lock
 396  * @outer_lock:           no nesting under innor or node lock
 397  *                        Lock order: 1) outer, 2) node, 3) inner
 398  * @binderfs_entry:       process-specific binderfs log file
 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         struct hlist_node deferred_work_node;
 412         int deferred_work;
 413         bool is_dead;
 414
 415         struct list_head todo;
 416         struct binder_stats stats;
 417         struct list_head delivered_death;
 418         int max_threads;
 419         int requested_threads;
 420         int requested_threads_started;
 421         int tmp_ref;
 422         long default_priority;
 423         struct dentry *debugfs_entry;
 424         struct binder_alloc alloc;
 425         struct binder_context *context;
 426         spinlock_t inner_lock;
 427         spinlock_t outer_lock;
 428         struct dentry *binderfs_entry;
 429 };
 430
 431 /**
 432  * struct binder_thread - binder thread bookkeeping
 433  * @proc:                 binder process for this thread
 434  *                        (invariant after initialization)
 435  * @rb_node:              element for proc->threads rbtree
 436  *                        (protected by @proc->inner_lock)
 437  * @waiting_thread_node:  element for @proc->waiting_threads list
 438  *                        (protected by @proc->inner_lock)
 439  * @pid:                  PID for this thread
 440  *                        (invariant after initialization)
 441  * @looper:               bitmap of looping state
 442  *                        (only accessed by this thread)
 443  * @looper_needs_return:  looping thread needs to exit driver
 444  *                        (no lock needed)
 445  * @transaction_stack:    stack of in-progress transactions for this thread
 446  *                        (protected by @proc->inner_lock)
 447  * @todo:                 list of work to do for this thread
 448  *                        (protected by @proc->inner_lock)
 449  * @process_todo:         whether work in @todo should be processed
 450  *                        (protected by @proc->inner_lock)
 451  * @return_error:         transaction errors reported by this thread
 452  *                        (only accessed by this thread)
 453  * @reply_error:          transaction errors reported by target thread
 454  *                        (protected by @proc->inner_lock)
 455  * @wait:                 wait queue for thread work
 456  * @stats:                per-thread statistics
 457  *                        (atomics, no lock needed)
 458  * @tmp_ref:              temporary reference to indicate thread is in use
 459  *                        (atomic since @proc->inner_lock cannot
 460  *                        always be acquired)
 461  * @is_dead:              thread is dead and awaiting free
 462  *                        when outstanding transactions are cleaned up
 463  *                        (protected by @proc->inner_lock)
 464  *
 465  * Bookkeeping structure for binder threads.
 466  */
 467 struct binder_thread {
 468         struct binder_proc *proc;
 469         struct rb_node rb_node;
 470         struct list_head waiting_thread_node;
 471         int pid;
 472         int looper;              /* only modified by this thread */
 473         bool looper_need_return; /* can be written by other thread */
 474         struct binder_transaction *transaction_stack;
 475         struct list_head todo;
 476         bool process_todo;
 477         struct binder_error return_error;
 478         struct binder_error reply_error;
 479         wait_queue_head_t wait;
 480         struct binder_stats stats;
 481         atomic_t tmp_ref;
 482         bool is_dead;
 483 };
 484
 485 /**
 486  * struct binder_txn_fd_fixup - transaction fd fixup list element
 487  * @fixup_entry:          list entry
 488  * @file:                 struct file to be associated with new fd
 489  * @offset:               offset in buffer data to this fixup
 490  *
 491  * List element for fd fixups in a transaction. Since file
 492  * descriptors need to be allocated in the context of the
 493  * target process, we pass each fd to be processed in this
 494  * struct.
 495  */
 496 struct binder_txn_fd_fixup {
 497         struct list_head fixup_entry;
 498         struct file *file;
 499         size_t offset;
 500 };
 501
 502 struct binder_transaction {
 503         int debug_id;
 504         struct binder_work work;
 505         struct binder_thread *from;
 506         struct binder_transaction *from_parent;
 507         struct binder_proc *to_proc;
 508         struct binder_thread *to_thread;
 509         struct binder_transaction *to_parent;
 510         unsigned need_reply:1;
 511         /* unsigned is_dead:1; */       /* not used at the moment */
 512
 513         struct binder_buffer *buffer;
 514         unsigned int    code;
 515         unsigned int    flags;
 516         long    priority;
 517         long    saved_priority;
 518         kuid_t  sender_euid;
 519         struct list_head fd_fixups;
 520         binder_uintptr_t security_ctx;
 521         /**
 522          * @lock:  protects @from, @to_proc, and @to_thread
 523          *
 524          * @from, @to_proc, and @to_thread can be set to NULL
 525          * during thread teardown
 526          */
 527         spinlock_t lock;
 528 };
 529
 530 /**
 531  * struct binder_object - union of flat binder object types
 532  * @hdr:   generic object header
 533  * @fbo:   binder object (nodes and refs)
 534  * @fdo:   file descriptor object
 535  * @bbo:   binder buffer pointer
 536  * @fdao:  file descriptor array
 537  *
 538  * Used for type-independent object copies
 539  */
 540 struct binder_object {
 541         union {
 542                 struct binder_object_header hdr;
 543                 struct flat_binder_object fbo;
 544                 struct binder_fd_object fdo;
 545                 struct binder_buffer_object bbo;
 546                 struct binder_fd_array_object fdao;
 547         };
 548 };
 549
 550 extern struct binder_transaction_log binder_transaction_log;
 551 extern struct binder_transaction_log binder_transaction_log_failed;
 552 #endif /* _LINUX_BINDER_INTERNAL_H */