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 #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
  88 static inline bool is_binderfs_device(const struct inode *inode)
  89 {
  90         return false;
  91 }
  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 }
  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
 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_COUNT
 134 };
 135
 136 struct binder_stats {
 137         atomic_t br[_IOC_NR(BR_TRANSACTION_PENDING_FROZEN) + 1];
 138         atomic_t bc[_IOC_NR(BC_REPLY_SG) + 1];
 139         atomic_t obj_created[BINDER_STAT_COUNT];
 140         atomic_t obj_deleted[BINDER_STAT_COUNT];
 141 };
 142
 143 /**
 144  * struct binder_work - work enqueued on a worklist
 145  * @entry:             node enqueued on list
 146  * @type:              type of work to be performed
 147  *
 148  * There are separate work lists for proc, thread, and node (async).
 149  */
 150 struct binder_work {
 151         struct list_head entry;
 152
 153         enum binder_work_type {
 154                 BINDER_WORK_TRANSACTION = 1,
 155                 BINDER_WORK_TRANSACTION_COMPLETE,
 156                 BINDER_WORK_TRANSACTION_PENDING,
 157                 BINDER_WORK_TRANSACTION_ONEWAY_SPAM_SUSPECT,
 158                 BINDER_WORK_RETURN_ERROR,
 159                 BINDER_WORK_NODE,
 160                 BINDER_WORK_DEAD_BINDER,
 161                 BINDER_WORK_DEAD_BINDER_AND_CLEAR,
 162                 BINDER_WORK_CLEAR_DEATH_NOTIFICATION,
 163         } type;
 164 };
 165
 166 struct binder_error {
 167         struct binder_work work;
 168         uint32_t cmd;
 169 };
 170
 171 /**
 172  * struct binder_node - binder node bookkeeping
 173  * @debug_id:             unique ID for debugging
 174  *                        (invariant after initialized)
 175  * @lock:                 lock for node fields
 176  * @work:                 worklist element for node work
 177  *                        (protected by @proc->inner_lock)
 178  * @rb_node:              element for proc->nodes tree
 179  *                        (protected by @proc->inner_lock)
 180  * @dead_node:            element for binder_dead_nodes list
 181  *                        (protected by binder_dead_nodes_lock)
 182  * @proc:                 binder_proc that owns this node
 183  *                        (invariant after initialized)
 184  * @refs:                 list of references on this node
 185  *                        (protected by @lock)
 186  * @internal_strong_refs: used to take strong references when
 187  *                        initiating a transaction
 188  *                        (protected by @proc->inner_lock if @proc
 189  *                        and by @lock)
 190  * @local_weak_refs:      weak user refs from local process
 191  *                        (protected by @proc->inner_lock if @proc
 192  *                        and by @lock)
 193  * @local_strong_refs:    strong user refs from local process
 194  *                        (protected by @proc->inner_lock if @proc
 195  *                        and by @lock)
 196  * @tmp_refs:             temporary kernel refs
 197  *                        (protected by @proc->inner_lock while @proc
 198  *                        is valid, and by binder_dead_nodes_lock
 199  *                        if @proc is NULL. During inc/dec and node release
 200  *                        it is also protected by @lock to provide safety
 201  *                        as the node dies and @proc becomes NULL)
 202  * @ptr:                  userspace pointer for node
 203  *                        (invariant, no lock needed)
 204  * @cookie:               userspace cookie for node
 205  *                        (invariant, no lock needed)
 206  * @has_strong_ref:       userspace notified of strong ref
 207  *                        (protected by @proc->inner_lock if @proc
 208  *                        and by @lock)
 209  * @pending_strong_ref:   userspace has acked notification of strong ref
 210  *                        (protected by @proc->inner_lock if @proc
 211  *                        and by @lock)
 212  * @has_weak_ref:         userspace notified of weak ref
 213  *                        (protected by @proc->inner_lock if @proc
 214  *                        and by @lock)
 215  * @pending_weak_ref:     userspace has acked notification of weak ref
 216  *                        (protected by @proc->inner_lock if @proc
 217  *                        and by @lock)
 218  * @has_async_transaction: async transaction to node in progress
 219  *                        (protected by @lock)
 220  * @accept_fds:           file descriptor operations supported for node
 221  *                        (invariant after initialized)
 222  * @min_priority:         minimum scheduling priority
 223  *                        (invariant after initialized)
 224  * @txn_security_ctx:     require sender's security context
 225  *                        (invariant after initialized)
 226  * @async_todo:           list of async work items
 227  *                        (protected by @proc->inner_lock)
 228  *
 229  * Bookkeeping structure for binder nodes.
 230  */
 231 struct binder_node {
 232         int debug_id;
 233         spinlock_t lock;
 234         struct binder_work work;
 235         union {
 236                 struct rb_node rb_node;
 237                 struct hlist_node dead_node;
 238         };
 239         struct binder_proc *proc;
 240         struct hlist_head refs;
 241         int internal_strong_refs;
 242         int local_weak_refs;
 243         int local_strong_refs;
 244         int tmp_refs;
 245         binder_uintptr_t ptr;
 246         binder_uintptr_t cookie;
 247         struct {
 248                 /*
 249                  * bitfield elements protected by
 250                  * proc inner_lock
 251                  */
 252                 u8 has_strong_ref:1;
 253                 u8 pending_strong_ref:1;
 254                 u8 has_weak_ref:1;
 255                 u8 pending_weak_ref:1;
 256         };
 257         struct {
 258                 /*
 259                  * invariant after initialization
 260                  */
 261                 u8 accept_fds:1;
 262                 u8 txn_security_ctx:1;
 263                 u8 min_priority;
 264         };
 265         bool has_async_transaction;
 266         struct list_head async_todo;
 267 };
 268
 269 struct binder_ref_death {
 270         /**
 271          * @work: worklist element for death notifications
 272          *        (protected by inner_lock of the proc that
 273          *        this ref belongs to)
 274          */
 275         struct binder_work work;
 276         binder_uintptr_t cookie;
 277 };
 278
 279 /**
 280  * struct binder_ref_data - binder_ref counts and id
 281  * @debug_id:        unique ID for the ref
 282  * @desc:            unique userspace handle for ref
 283  * @strong:          strong ref count (debugging only if not locked)
 284  * @weak:            weak ref count (debugging only if not locked)
 285  *
 286  * Structure to hold ref count and ref id information. Since
 287  * the actual ref can only be accessed with a lock, this structure
 288  * is used to return information about the ref to callers of
 289  * ref inc/dec functions.
 290  */
 291 struct binder_ref_data {
 292         int debug_id;
 293         uint32_t desc;
 294         int strong;
 295         int weak;
 296 };
 297
 298 /**
 299  * struct binder_ref - struct to track references on nodes
 300  * @data:        binder_ref_data containing id, handle, and current refcounts
 301  * @rb_node_desc: node for lookup by @data.desc in proc's rb_tree
 302  * @rb_node_node: node for lookup by @node in proc's rb_tree
 303  * @node_entry:  list entry for node->refs list in target node
 304  *               (protected by @node->lock)
 305  * @proc:        binder_proc containing ref
 306  * @node:        binder_node of target node. When cleaning up a
 307  *               ref for deletion in binder_cleanup_ref, a non-NULL
 308  *               @node indicates the node must be freed
 309  * @death:       pointer to death notification (ref_death) if requested
 310  *               (protected by @node->lock)
 311  *
 312  * Structure to track references from procA to target node (on procB). This
 313  * structure is unsafe to access without holding @proc->outer_lock.
 314  */
 315 struct binder_ref {
 316         /* Lookups needed: */
 317         /*   node + proc => ref (transaction) */
 318         /*   desc + proc => ref (transaction, inc/dec ref) */
 319         /*   node => refs + procs (proc exit) */
 320         struct binder_ref_data data;
 321         struct rb_node rb_node_desc;
 322         struct rb_node rb_node_node;
 323         struct hlist_node node_entry;
 324         struct binder_proc *proc;
 325         struct binder_node *node;
 326         struct binder_ref_death *death;
 327 };
 328
 329 /**
 330  * struct binder_proc - binder process bookkeeping
 331  * @proc_node:            element for binder_procs list
 332  * @threads:              rbtree of binder_threads in this proc
 333  *                        (protected by @inner_lock)
 334  * @nodes:                rbtree of binder nodes associated with
 335  *                        this proc ordered by node->ptr
 336  *                        (protected by @inner_lock)
 337  * @refs_by_desc:         rbtree of refs ordered by ref->desc
 338  *                        (protected by @outer_lock)
 339  * @refs_by_node:         rbtree of refs ordered by ref->node
 340  *                        (protected by @outer_lock)
 341  * @waiting_threads:      threads currently waiting for proc work
 342  *                        (protected by @inner_lock)
 343  * @pid                   PID of group_leader of process
 344  *                        (invariant after initialized)
 345  * @tsk                   task_struct for group_leader of process
 346  *                        (invariant after initialized)
 347  * @cred                  struct cred associated with the `struct file`
 348  *                        in binder_open()
 349  *                        (invariant after initialized)
 350  * @deferred_work_node:   element for binder_deferred_list
 351  *                        (protected by binder_deferred_lock)
 352  * @deferred_work:        bitmap of deferred work to perform
 353  *                        (protected by binder_deferred_lock)
 354  * @outstanding_txns:     number of transactions to be transmitted before
 355  *                        processes in freeze_wait are woken up
 356  *                        (protected by @inner_lock)
 357  * @is_dead:              process is dead and awaiting free
 358  *                        when outstanding transactions are cleaned up
 359  *                        (protected by @inner_lock)
 360  * @is_frozen:            process is frozen and unable to service
 361  *                        binder transactions
 362  *                        (protected by @inner_lock)
 363  * @sync_recv:            process received sync transactions since last frozen
 364  *                        bit 0: received sync transaction after being frozen
 365  *                        bit 1: new pending sync transaction during freezing
 366  *                        (protected by @inner_lock)
 367  * @async_recv:           process received async transactions since last frozen
 368  *                        (protected by @inner_lock)
 369  * @freeze_wait:          waitqueue of processes waiting for all outstanding
 370  *                        transactions to be processed
 371  *                        (protected by @inner_lock)
 372  * @dmap                  dbitmap to manage available reference descriptors
 373  *                        (protected by @outer_lock)
 374  * @todo:                 list of work for this process
 375  *                        (protected by @inner_lock)
 376  * @stats:                per-process binder statistics
 377  *                        (atomics, no lock needed)
 378  * @delivered_death:      list of delivered death notification
 379  *                        (protected by @inner_lock)
 380  * @max_threads:          cap on number of binder threads
 381  *                        (protected by @inner_lock)
 382  * @requested_threads:    number of binder threads requested but not
 383  *                        yet started. In current implementation, can
 384  *                        only be 0 or 1.
 385  *                        (protected by @inner_lock)
 386  * @requested_threads_started: number binder threads started
 387  *                        (protected by @inner_lock)
 388  * @tmp_ref:              temporary reference to indicate proc is in use
 389  *                        (protected by @inner_lock)
 390  * @default_priority:     default scheduler priority
 391  *                        (invariant after initialized)
 392  * @debugfs_entry:        debugfs node
 393  * @alloc:                binder allocator bookkeeping
 394  * @context:              binder_context for this proc
 395  *                        (invariant after initialized)
 396  * @inner_lock:           can nest under outer_lock and/or node lock
 397  * @outer_lock:           no nesting under innor or node lock
 398  *                        Lock order: 1) outer, 2) node, 3) inner
 399  * @binderfs_entry:       process-specific binderfs log file
 400  * @oneway_spam_detection_enabled: process enabled oneway spam detection
 401  *                        or not
 402  *
 403  * Bookkeeping structure for binder processes
 404  */
 405 struct binder_proc {
 406         struct hlist_node proc_node;
 407         struct rb_root threads;
 408         struct rb_root nodes;
 409         struct rb_root refs_by_desc;
 410         struct rb_root refs_by_node;
 411         struct list_head waiting_threads;
 412         int pid;
 413         struct task_struct *tsk;
 414         const struct cred *cred;
 415         struct hlist_node deferred_work_node;
 416         int deferred_work;
 417         int outstanding_txns;
 418         bool is_dead;
 419         bool is_frozen;
 420         bool sync_recv;
 421         bool async_recv;
 422         wait_queue_head_t freeze_wait;
 423         struct dbitmap dmap;
 424         struct list_head todo;
 425         struct binder_stats stats;
 426         struct list_head delivered_death;
 427         u32 max_threads;
 428         int requested_threads;
 429         int requested_threads_started;
 430         int tmp_ref;
 431         long default_priority;
 432         struct dentry *debugfs_entry;
 433         struct binder_alloc alloc;
 434         struct binder_context *context;
 435         spinlock_t inner_lock;
 436         spinlock_t outer_lock;
 437         struct dentry *binderfs_entry;
 438         bool oneway_spam_detection_enabled;
 439 };
 440
 441 /**
 442  * struct binder_thread - binder thread bookkeeping
 443  * @proc:                 binder process for this thread
 444  *                        (invariant after initialization)
 445  * @rb_node:              element for proc->threads rbtree
 446  *                        (protected by @proc->inner_lock)
 447  * @waiting_thread_node:  element for @proc->waiting_threads list
 448  *                        (protected by @proc->inner_lock)
 449  * @pid:                  PID for this thread
 450  *                        (invariant after initialization)
 451  * @looper:               bitmap of looping state
 452  *                        (only accessed by this thread)
 453  * @looper_needs_return:  looping thread needs to exit driver
 454  *                        (no lock needed)
 455  * @transaction_stack:    stack of in-progress transactions for this thread
 456  *                        (protected by @proc->inner_lock)
 457  * @todo:                 list of work to do for this thread
 458  *                        (protected by @proc->inner_lock)
 459  * @process_todo:         whether work in @todo should be processed
 460  *                        (protected by @proc->inner_lock)
 461  * @return_error:         transaction errors reported by this thread
 462  *                        (only accessed by this thread)
 463  * @reply_error:          transaction errors reported by target thread
 464  *                        (protected by @proc->inner_lock)
 465  * @ee:                   extended error information from this thread
 466  *                        (protected by @proc->inner_lock)
 467  * @wait:                 wait queue for thread work
 468  * @stats:                per-thread statistics
 469  *                        (atomics, no lock needed)
 470  * @tmp_ref:              temporary reference to indicate thread is in use
 471  *                        (atomic since @proc->inner_lock cannot
 472  *                        always be acquired)
 473  * @is_dead:              thread is dead and awaiting free
 474  *                        when outstanding transactions are cleaned up
 475  *                        (protected by @proc->inner_lock)
 476  *
 477  * Bookkeeping structure for binder threads.
 478  */
 479 struct binder_thread {
 480         struct binder_proc *proc;
 481         struct rb_node rb_node;
 482         struct list_head waiting_thread_node;
 483         int pid;
 484         int looper;              /* only modified by this thread */
 485         bool looper_need_return; /* can be written by other thread */
 486         struct binder_transaction *transaction_stack;
 487         struct list_head todo;
 488         bool process_todo;
 489         struct binder_error return_error;
 490         struct binder_error reply_error;
 491         struct binder_extended_error ee;
 492         wait_queue_head_t wait;
 493         struct binder_stats stats;
 494         atomic_t tmp_ref;
 495         bool is_dead;
 496 };
 497
 498 /**
 499  * struct binder_txn_fd_fixup - transaction fd fixup list element
 500  * @fixup_entry:          list entry
 501  * @file:                 struct file to be associated with new fd
 502  * @offset:               offset in buffer data to this fixup
 503  * @target_fd:            fd to use by the target to install @file
 504  *
 505  * List element for fd fixups in a transaction. Since file
 506  * descriptors need to be allocated in the context of the
 507  * target process, we pass each fd to be processed in this
 508  * struct.
 509  */
 510 struct binder_txn_fd_fixup {
 511         struct list_head fixup_entry;
 512         struct file *file;
 513         size_t offset;
 514         int target_fd;
 515 };
 516
 517 struct binder_transaction {
 518         int debug_id;
 519         struct binder_work work;
 520         struct binder_thread *from;
 521         pid_t from_pid;
 522         pid_t from_tid;
 523         struct binder_transaction *from_parent;
 524         struct binder_proc *to_proc;
 525         struct binder_thread *to_thread;
 526         struct binder_transaction *to_parent;
 527         unsigned need_reply:1;
 528         /* unsigned is_dead:1; */       /* not used at the moment */
 529
 530         struct binder_buffer *buffer;
 531         unsigned int    code;
 532         unsigned int    flags;
 533         long    priority;
 534         long    saved_priority;
 535         kuid_t  sender_euid;
 536         ktime_t start_time;
 537         struct list_head fd_fixups;
 538         binder_uintptr_t security_ctx;
 539         /**
 540          * @lock:  protects @from, @to_proc, and @to_thread
 541          *
 542          * @from, @to_proc, and @to_thread can be set to NULL
 543          * during thread teardown
 544          */
 545         spinlock_t lock;
 546 };
 547
 548 /**
 549  * struct binder_object - union of flat binder object types
 550  * @hdr:   generic object header
 551  * @fbo:   binder object (nodes and refs)
 552  * @fdo:   file descriptor object
 553  * @bbo:   binder buffer pointer
 554  * @fdao:  file descriptor array
 555  *
 556  * Used for type-independent object copies
 557  */
 558 struct binder_object {
 559         union {
 560                 struct binder_object_header hdr;
 561                 struct flat_binder_object fbo;
 562                 struct binder_fd_object fdo;
 563                 struct binder_buffer_object bbo;
 564                 struct binder_fd_array_object fdao;
 565         };
 566 };
 567
 568 #endif /* _LINUX_BINDER_INTERNAL_H */