/* binder.c * * Android IPC Subsystem * * Copyright (C) 2007-2008 Google, Inc. * * This software is licensed under the terms of the GNU General Public * License version 2, as published by the Free Software Foundation, and * may be copied, distributed, and modified under those terms. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * */ /* * Locking overview * * There are 3 main spinlocks which must be acquired in the * order shown: * * 1) proc->outer_lock : protects binder_ref * binder_proc_lock() and binder_proc_unlock() are * used to acq/rel. * 2) node->lock : protects most fields of binder_node. * binder_node_lock() and binder_node_unlock() are * used to acq/rel * 3) proc->inner_lock : protects the thread and node lists * (proc->threads, proc->waiting_threads, proc->nodes) * and all todo lists associated with the binder_proc * (proc->todo, thread->todo, proc->delivered_death and * node->async_todo), as well as thread->transaction_stack * binder_inner_proc_lock() and binder_inner_proc_unlock() * are used to acq/rel * * Any lock under procA must never be nested under any lock at the same * level or below on procB. * * Functions that require a lock held on entry indicate which lock * in the suffix of the function name: * * foo_olocked() : requires node->outer_lock * foo_nlocked() : requires node->lock * foo_ilocked() : requires proc->inner_lock * foo_oilocked(): requires proc->outer_lock and proc->inner_lock * foo_nilocked(): requires node->lock and proc->inner_lock * ... */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "binder_alloc.h" #include "binder_trace.h" static HLIST_HEAD(binder_deferred_list); static DEFINE_MUTEX(binder_deferred_lock); static HLIST_HEAD(binder_devices); static HLIST_HEAD(binder_procs); static DEFINE_MUTEX(binder_procs_lock); static HLIST_HEAD(binder_dead_nodes); static DEFINE_SPINLOCK(binder_dead_nodes_lock); static struct dentry *binder_debugfs_dir_entry_root; static struct dentry *binder_debugfs_dir_entry_proc; static atomic_t binder_last_id; static int proc_show(struct seq_file *m, void *unused); DEFINE_SHOW_ATTRIBUTE(proc); /* This is only defined in include/asm-arm/sizes.h */ #ifndef SZ_1K #define SZ_1K 0x400 #endif #ifndef SZ_4M #define SZ_4M 0x400000 #endif #define FORBIDDEN_MMAP_FLAGS (VM_WRITE) enum { BINDER_DEBUG_USER_ERROR = 1U << 0, BINDER_DEBUG_FAILED_TRANSACTION = 1U << 1, BINDER_DEBUG_DEAD_TRANSACTION = 1U << 2, BINDER_DEBUG_OPEN_CLOSE = 1U << 3, BINDER_DEBUG_DEAD_BINDER = 1U << 4, BINDER_DEBUG_DEATH_NOTIFICATION = 1U << 5, BINDER_DEBUG_READ_WRITE = 1U << 6, BINDER_DEBUG_USER_REFS = 1U << 7, BINDER_DEBUG_THREADS = 1U << 8, BINDER_DEBUG_TRANSACTION = 1U << 9, BINDER_DEBUG_TRANSACTION_COMPLETE = 1U << 10, BINDER_DEBUG_FREE_BUFFER = 1U << 11, BINDER_DEBUG_INTERNAL_REFS = 1U << 12, BINDER_DEBUG_PRIORITY_CAP = 1U << 13, BINDER_DEBUG_SPINLOCKS = 1U << 14, }; static uint32_t binder_debug_mask = BINDER_DEBUG_USER_ERROR | BINDER_DEBUG_FAILED_TRANSACTION | BINDER_DEBUG_DEAD_TRANSACTION; module_param_named(debug_mask, binder_debug_mask, uint, 0644); static char *binder_devices_param = CONFIG_ANDROID_BINDER_DEVICES; module_param_named(devices, binder_devices_param, charp, 0444); static DECLARE_WAIT_QUEUE_HEAD(binder_user_error_wait); static int binder_stop_on_user_error; static int binder_set_stop_on_user_error(const char *val, const struct kernel_param *kp) { int ret; ret = param_set_int(val, kp); if (binder_stop_on_user_error < 2) wake_up(&binder_user_error_wait); return ret; } module_param_call(stop_on_user_error, binder_set_stop_on_user_error, param_get_int, &binder_stop_on_user_error, 0644); #define binder_debug(mask, x...) \ do { \ if (binder_debug_mask & mask) \ pr_info_ratelimited(x); \ } while (0) #define binder_user_error(x...) \ do { \ if (binder_debug_mask & BINDER_DEBUG_USER_ERROR) \ pr_info_ratelimited(x); \ if (binder_stop_on_user_error) \ binder_stop_on_user_error = 2; \ } while (0) #define to_flat_binder_object(hdr) \ container_of(hdr, struct flat_binder_object, hdr) #define to_binder_fd_object(hdr) container_of(hdr, struct binder_fd_object, hdr) #define to_binder_buffer_object(hdr) \ container_of(hdr, struct binder_buffer_object, hdr) #define to_binder_fd_array_object(hdr) \ container_of(hdr, struct binder_fd_array_object, hdr) enum binder_stat_types { BINDER_STAT_PROC, BINDER_STAT_THREAD, BINDER_STAT_NODE, BINDER_STAT_REF, BINDER_STAT_DEATH, BINDER_STAT_TRANSACTION, BINDER_STAT_TRANSACTION_COMPLETE, BINDER_STAT_COUNT }; struct binder_stats { atomic_t br[_IOC_NR(BR_FAILED_REPLY) + 1]; atomic_t bc[_IOC_NR(BC_REPLY_SG) + 1]; atomic_t obj_created[BINDER_STAT_COUNT]; atomic_t obj_deleted[BINDER_STAT_COUNT]; }; static struct binder_stats binder_stats; static inline void binder_stats_deleted(enum binder_stat_types type) { atomic_inc(&binder_stats.obj_deleted[type]); } static inline void binder_stats_created(enum binder_stat_types type) { atomic_inc(&binder_stats.obj_created[type]); } struct binder_transaction_log_entry { int debug_id; int debug_id_done; int call_type; int from_proc; int from_thread; int target_handle; int to_proc; int to_thread; int to_node; int data_size; int offsets_size; int return_error_line; uint32_t return_error; uint32_t return_error_param; const char *context_name; }; struct binder_transaction_log { atomic_t cur; bool full; struct binder_transaction_log_entry entry[32]; }; static struct binder_transaction_log binder_transaction_log; static struct binder_transaction_log binder_transaction_log_failed; static struct binder_transaction_log_entry *binder_transaction_log_add( struct binder_transaction_log *log) { struct binder_transaction_log_entry *e; unsigned int cur = atomic_inc_return(&log->cur); if (cur >= ARRAY_SIZE(log->entry)) log->full = true; e = &log->entry[cur % ARRAY_SIZE(log->entry)]; WRITE_ONCE(e->debug_id_done, 0); /* * write-barrier to synchronize access to e->debug_id_done. * We make sure the initialized 0 value is seen before * memset() other fields are zeroed by memset. */ smp_wmb(); memset(e, 0, sizeof(*e)); return e; } struct binder_context { struct binder_node *binder_context_mgr_node; struct mutex context_mgr_node_lock; kuid_t binder_context_mgr_uid; const char *name; }; struct binder_device { struct hlist_node hlist; struct miscdevice miscdev; struct binder_context context; }; /** * struct binder_work - work enqueued on a worklist * @entry: node enqueued on list * @type: type of work to be performed * * There are separate work lists for proc, thread, and node (async). */ struct binder_work { struct list_head entry; enum { BINDER_WORK_TRANSACTION = 1, BINDER_WORK_TRANSACTION_COMPLETE, BINDER_WORK_RETURN_ERROR, BINDER_WORK_NODE, BINDER_WORK_DEAD_BINDER, BINDER_WORK_DEAD_BINDER_AND_CLEAR, BINDER_WORK_CLEAR_DEATH_NOTIFICATION, } type; }; struct binder_error { struct binder_work work; uint32_t cmd; }; /** * struct binder_node - binder node bookkeeping * @debug_id: unique ID for debugging * (invariant after initialized) * @lock: lock for node fields * @work: worklist element for node work * (protected by @proc->inner_lock) * @rb_node: element for proc->nodes tree * (protected by @proc->inner_lock) * @dead_node: element for binder_dead_nodes list * (protected by binder_dead_nodes_lock) * @proc: binder_proc that owns this node * (invariant after initialized) * @refs: list of references on this node * (protected by @lock) * @internal_strong_refs: used to take strong references when * initiating a transaction * (protected by @proc->inner_lock if @proc * and by @lock) * @local_weak_refs: weak user refs from local process * (protected by @proc->inner_lock if @proc * and by @lock) * @local_strong_refs: strong user refs from local process * (protected by @proc->inner_lock if @proc * and by @lock) * @tmp_refs: temporary kernel refs * (protected by @proc->inner_lock while @proc * is valid, and by binder_dead_nodes_lock * if @proc is NULL. During inc/dec and node release * it is also protected by @lock to provide safety * as the node dies and @proc becomes NULL) * @ptr: userspace pointer for node * (invariant, no lock needed) * @cookie: userspace cookie for node * (invariant, no lock needed) * @has_strong_ref: userspace notified of strong ref * (protected by @proc->inner_lock if @proc * and by @lock) * @pending_strong_ref: userspace has acked notification of strong ref * (protected by @proc->inner_lock if @proc * and by @lock) * @has_weak_ref: userspace notified of weak ref * (protected by @proc->inner_lock if @proc * and by @lock) * @pending_weak_ref: userspace has acked notification of weak ref * (protected by @proc->inner_lock if @proc * and by @lock) * @has_async_transaction: async transaction to node in progress * (protected by @lock) * @accept_fds: file descriptor operations supported for node * (invariant after initialized) * @min_priority: minimum scheduling priority * (invariant after initialized) * @async_todo: list of async work items * (protected by @proc->inner_lock) * * Bookkeeping structure for binder nodes. */ struct binder_node { int debug_id; spinlock_t lock; struct binder_work work; union { struct rb_node rb_node; struct hlist_node dead_node; }; struct binder_proc *proc; struct hlist_head refs; int internal_strong_refs; int local_weak_refs; int local_strong_refs; int tmp_refs; binder_uintptr_t ptr; binder_uintptr_t cookie; struct { /* * bitfield elements protected by * proc inner_lock */ u8 has_strong_ref:1; u8 pending_strong_ref:1; u8 has_weak_ref:1; u8 pending_weak_ref:1; }; struct { /* * invariant after initialization */ u8 accept_fds:1; u8 min_priority; }; bool has_async_transaction; struct list_head async_todo; }; struct binder_ref_death { /** * @work: worklist element for death notifications * (protected by inner_lock of the proc that * this ref belongs to) */ struct binder_work work; binder_uintptr_t cookie; }; /** * struct binder_ref_data - binder_ref counts and id * @debug_id: unique ID for the ref * @desc: unique userspace handle for ref * @strong: strong ref count (debugging only if not locked) * @weak: weak ref count (debugging only if not locked) * * Structure to hold ref count and ref id information. Since * the actual ref can only be accessed with a lock, this structure * is used to return information about the ref to callers of * ref inc/dec functions. */ struct binder_ref_data { int debug_id; uint32_t desc; int strong; int weak; }; /** * struct binder_ref - struct to track references on nodes * @data: binder_ref_data containing id, handle, and current refcounts * @rb_node_desc: node for lookup by @data.desc in proc's rb_tree * @rb_node_node: node for lookup by @node in proc's rb_tree * @node_entry: list entry for node->refs list in target node * (protected by @node->lock) * @proc: binder_proc containing ref * @node: binder_node of target node. When cleaning up a * ref for deletion in binder_cleanup_ref, a non-NULL * @node indicates the node must be freed * @death: pointer to death notification (ref_death) if requested * (protected by @node->lock) * * Structure to track references from procA to target node (on procB). This * structure is unsafe to access without holding @proc->outer_lock. */ struct binder_ref { /* Lookups needed: */ /* node + proc => ref (transaction) */ /* desc + proc => ref (transaction, inc/dec ref) */ /* node => refs + procs (proc exit) */ struct binder_ref_data data; struct rb_node rb_node_desc; struct rb_node rb_node_node; struct hlist_node node_entry; struct binder_proc *proc; struct binder_node *node; struct binder_ref_death *death; }; enum binder_deferred_state { BINDER_DEFERRED_FLUSH = 0x01, BINDER_DEFERRED_RELEASE = 0x02, }; /** * struct binder_proc - binder process bookkeeping * @proc_node: element for binder_procs list * @threads: rbtree of binder_threads in this proc * (protected by @inner_lock) * @nodes: rbtree of binder nodes associated with * this proc ordered by node->ptr * (protected by @inner_lock) * @refs_by_desc: rbtree of refs ordered by ref->desc * (protected by @outer_lock) * @refs_by_node: rbtree of refs ordered by ref->node * (protected by @outer_lock) * @waiting_threads: threads currently waiting for proc work * (protected by @inner_lock) * @pid PID of group_leader of process * (invariant after initialized) * @tsk task_struct for group_leader of process * (invariant after initialized) * @deferred_work_node: element for binder_deferred_list * (protected by binder_deferred_lock) * @deferred_work: bitmap of deferred work to perform * (protected by binder_deferred_lock) * @is_dead: process is dead and awaiting free * when outstanding transactions are cleaned up * (protected by @inner_lock) * @todo: list of work for this process * (protected by @inner_lock) * @stats: per-process binder statistics * (atomics, no lock needed) * @delivered_death: list of delivered death notification * (protected by @inner_lock) * @max_threads: cap on number of binder threads * (protected by @inner_lock) * @requested_threads: number of binder threads requested but not * yet started. In current implementation, can * only be 0 or 1. * (protected by @inner_lock) * @requested_threads_started: number binder threads started * (protected by @inner_lock) * @tmp_ref: temporary reference to indicate proc is in use * (protected by @inner_lock) * @default_priority: default scheduler priority * (invariant after initialized) * @debugfs_entry: debugfs node * @alloc: binder allocator bookkeeping * @context: binder_context for this proc * (invariant after initialized) * @inner_lock: can nest under outer_lock and/or node lock * @outer_lock: no nesting under innor or node lock * Lock order: 1) outer, 2) node, 3) inner * * Bookkeeping structure for binder processes */ struct binder_proc { struct hlist_node proc_node; struct rb_root threads; struct rb_root nodes; struct rb_root refs_by_desc; struct rb_root refs_by_node; struct list_head waiting_threads; int pid; struct task_struct *tsk; struct hlist_node deferred_work_node; int deferred_work; bool is_dead; struct list_head todo; struct binder_stats stats; struct list_head delivered_death; int max_threads; int requested_threads; int requested_threads_started; int tmp_ref; long default_priority; struct dentry *debugfs_entry; struct binder_alloc alloc; struct binder_context *context; spinlock_t inner_lock; spinlock_t outer_lock; }; enum { BINDER_LOOPER_STATE_REGISTERED = 0x01, BINDER_LOOPER_STATE_ENTERED = 0x02, BINDER_LOOPER_STATE_EXITED = 0x04, BINDER_LOOPER_STATE_INVALID = 0x08, BINDER_LOOPER_STATE_WAITING = 0x10, BINDER_LOOPER_STATE_POLL = 0x20, }; /** * struct binder_thread - binder thread bookkeeping * @proc: binder process for this thread * (invariant after initialization) * @rb_node: element for proc->threads rbtree * (protected by @proc->inner_lock) * @waiting_thread_node: element for @proc->waiting_threads list * (protected by @proc->inner_lock) * @pid: PID for this thread * (invariant after initialization) * @looper: bitmap of looping state * (only accessed by this thread) * @looper_needs_return: looping thread needs to exit driver * (no lock needed) * @transaction_stack: stack of in-progress transactions for this thread * (protected by @proc->inner_lock) * @todo: list of work to do for this thread * (protected by @proc->inner_lock) * @process_todo: whether work in @todo should be processed * (protected by @proc->inner_lock) * @return_error: transaction errors reported by this thread * (only accessed by this thread) * @reply_error: transaction errors reported by target thread * (protected by @proc->inner_lock) * @wait: wait queue for thread work * @stats: per-thread statistics * (atomics, no lock needed) * @tmp_ref: temporary reference to indicate thread is in use * (atomic since @proc->inner_lock cannot * always be acquired) * @is_dead: thread is dead and awaiting free * when outstanding transactions are cleaned up * (protected by @proc->inner_lock) * * Bookkeeping structure for binder threads. */ struct binder_thread { struct binder_proc *proc; struct rb_node rb_node; struct list_head waiting_thread_node; int pid; int looper; /* only modified by this thread */ bool looper_need_return; /* can be written by other thread */ struct binder_transaction *transaction_stack; struct list_head todo; bool process_todo; struct binder_error return_error; struct binder_error reply_error; wait_queue_head_t wait; struct binder_stats stats; atomic_t tmp_ref; bool is_dead; }; /** * struct binder_txn_fd_fixup - transaction fd fixup list element * @fixup_entry: list entry * @file: struct file to be associated with new fd * @offset: offset in buffer data to this fixup * * List element for fd fixups in a transaction. Since file * descriptors need to be allocated in the context of the * target process, we pass each fd to be processed in this * struct. */ struct binder_txn_fd_fixup { struct list_head fixup_entry; struct file *file; size_t offset; }; struct binder_transaction { int debug_id; struct binder_work work; struct binder_thread *from; struct binder_transaction *from_parent; struct binder_proc *to_proc; struct binder_thread *to_thread; struct binder_transaction *to_parent; unsigned need_reply:1; /* unsigned is_dead:1; */ /* not used at the moment */ struct binder_buffer *buffer; unsigned int code; unsigned int flags; long priority; long saved_priority; kuid_t sender_euid; struct list_head fd_fixups; /** * @lock: protects @from, @to_proc, and @to_thread * * @from, @to_proc, and @to_thread can be set to NULL * during thread teardown */ spinlock_t lock; }; /** * binder_proc_lock() - Acquire outer lock for given binder_proc * @proc: struct binder_proc to acquire * * Acquires proc->outer_lock. Used to protect binder_ref * structures associated with the given proc. */ #define binder_proc_lock(proc) _binder_proc_lock(proc, __LINE__) static void _binder_proc_lock(struct binder_proc *proc, int line) __acquires(&proc->outer_lock) { binder_debug(BINDER_DEBUG_SPINLOCKS, "%s: line=%d\n", __func__, line); spin_lock(&proc->outer_lock); } /** * binder_proc_unlock() - Release spinlock for given binder_proc * @proc: struct binder_proc to acquire * * Release lock acquired via binder_proc_lock() */ #define binder_proc_unlock(_proc) _binder_proc_unlock(_proc, __LINE__) static void _binder_proc_unlock(struct binder_proc *proc, int line) __releases(&proc->outer_lock) { binder_debug(BINDER_DEBUG_SPINLOCKS, "%s: line=%d\n", __func__, line); spin_unlock(&proc->outer_lock); } /** * binder_inner_proc_lock() - Acquire inner lock for given binder_proc * @proc: struct binder_proc to acquire * * Acquires proc->inner_lock. Used to protect todo lists */ #define binder_inner_proc_lock(proc) _binder_inner_proc_lock(proc, __LINE__) static void _binder_inner_proc_lock(struct binder_proc *proc, int line) __acquires(&proc->inner_lock) { binder_debug(BINDER_DEBUG_SPINLOCKS, "%s: line=%d\n", __func__, line); spin_lock(&proc->inner_lock); } /** * binder_inner_proc_unlock() - Release inner lock for given binder_proc * @proc: struct binder_proc to acquire * * Release lock acquired via binder_inner_proc_lock() */ #define binder_inner_proc_unlock(proc) _binder_inner_proc_unlock(proc, __LINE__) static void _binder_inner_proc_unlock(struct binder_proc *proc, int line) __releases(&proc->inner_lock) { binder_debug(BINDER_DEBUG_SPINLOCKS, "%s: line=%d\n", __func__, line); spin_unlock(&proc->inner_lock); } /** * binder_node_lock() - Acquire spinlock for given binder_node * @node: struct binder_node to acquire * * Acquires node->lock. Used to protect binder_node fields */ #define binder_node_lock(node) _binder_node_lock(node, __LINE__) static void _binder_node_lock(struct binder_node *node, int line) __acquires(&node->lock) { binder_debug(BINDER_DEBUG_SPINLOCKS, "%s: line=%d\n", __func__, line); spin_lock(&node->lock); } /** * binder_node_unlock() - Release spinlock for given binder_proc * @node: struct binder_node to acquire * * Release lock acquired via binder_node_lock() */ #define binder_node_unlock(node) _binder_node_unlock(node, __LINE__) static void _binder_node_unlock(struct binder_node *node, int line) __releases(&node->lock) { binder_debug(BINDER_DEBUG_SPINLOCKS, "%s: line=%d\n", __func__, line); spin_unlock(&node->lock); } /** * binder_node_inner_lock() - Acquire node and inner locks * @node: struct binder_node to acquire * * Acquires node->lock. If node->proc also acquires * proc->inner_lock. Used to protect binder_node fields */ #define binder_node_inner_lock(node) _binder_node_inner_lock(node, __LINE__) static void _binder_node_inner_lock(struct binder_node *node, int line) __acquires(&node->lock) __acquires(&node->proc->inner_lock) { binder_debug(BINDER_DEBUG_SPINLOCKS, "%s: line=%d\n", __func__, line); spin_lock(&node->lock); if (node->proc) binder_inner_proc_lock(node->proc); else /* annotation for sparse */ __acquire(&node->proc->inner_lock); } /** * binder_node_unlock() - Release node and inner locks * @node: struct binder_node to acquire * * Release lock acquired via binder_node_lock() */ #define binder_node_inner_unlock(node) _binder_node_inner_unlock(node, __LINE__) static void _binder_node_inner_unlock(struct binder_node *node, int line) __releases(&node->lock) __releases(&node->proc->inner_lock) { struct binder_proc *proc = node->proc; binder_debug(BINDER_DEBUG_SPINLOCKS, "%s: line=%d\n", __func__, line); if (proc) binder_inner_proc_unlock(proc); else /* annotation for sparse */ __release(&node->proc->inner_lock); spin_unlock(&node->lock); } static bool binder_worklist_empty_ilocked(struct list_head *list) { return list_empty(list); } /** * binder_worklist_empty() - Check if no items on the work list * @proc: binder_proc associated with list * @list: list to check * * Return: true if there are no items on list, else false */ static bool binder_worklist_empty(struct binder_proc *proc, struct list_head *list) { bool ret; binder_inner_proc_lock(proc); ret = binder_worklist_empty_ilocked(list); binder_inner_proc_unlock(proc); return ret; } /** * binder_enqueue_work_ilocked() - Add an item to the work list * @work: struct binder_work to add to list * @target_list: list to add work to * * Adds the work to the specified list. Asserts that work * is not already on a list. * * Requires the proc->inner_lock to be held. */ static void binder_enqueue_work_ilocked(struct binder_work *work, struct list_head *target_list) { BUG_ON(target_list == NULL); BUG_ON(work->entry.next && !list_empty(&work->entry)); list_add_tail(&work->entry, target_list); } /** * binder_enqueue_deferred_thread_work_ilocked() - Add deferred thread work * @thread: thread to queue work to * @work: struct binder_work to add to list * * Adds the work to the todo list of the thread. Doesn't set the process_todo * flag, which means that (if it wasn't already set) the thread will go to * sleep without handling this work when it calls read. * * Requires the proc->inner_lock to be held. */ static void binder_enqueue_deferred_thread_work_ilocked(struct binder_thread *thread, struct binder_work *work) { WARN_ON(!list_empty(&thread->waiting_thread_node)); binder_enqueue_work_ilocked(work, &thread->todo); } /** * binder_enqueue_thread_work_ilocked() - Add an item to the thread work list * @thread: thread to queue work to * @work: struct binder_work to add to list * * Adds the work to the todo list of the thread, and enables processing * of the todo queue. * * Requires the proc->inner_lock to be held. */ static void binder_enqueue_thread_work_ilocked(struct binder_thread *thread, struct binder_work *work) { WARN_ON(!list_empty(&thread->waiting_thread_node)); binder_enqueue_work_ilocked(work, &thread->todo); thread->process_todo = true; } /** * binder_enqueue_thread_work() - Add an item to the thread work list * @thread: thread to queue work to * @work: struct binder_work to add to list * * Adds the work to the todo list of the thread, and enables processing * of the todo queue. */ static void binder_enqueue_thread_work(struct binder_thread *thread, struct binder_work *work) { binder_inner_proc_lock(thread->proc); binder_enqueue_thread_work_ilocked(thread, work); binder_inner_proc_unlock(thread->proc); } static void binder_dequeue_work_ilocked(struct binder_work *work) { list_del_init(&work->entry); } /** * binder_dequeue_work() - Removes an item from the work list * @proc: binder_proc associated with list * @work: struct binder_work to remove from list * * Removes the specified work item from whatever list it is on. * Can safely be called if work is not on any list. */ static void binder_dequeue_work(struct binder_proc *proc, struct binder_work *work) { binder_inner_proc_lock(proc); binder_dequeue_work_ilocked(work); binder_inner_proc_unlock(proc); } static struct binder_work *binder_dequeue_work_head_ilocked( struct list_head *list) { struct binder_work *w; w = list_first_entry_or_null(list, struct binder_work, entry); if (w) list_del_init(&w->entry); return w; } /** * binder_dequeue_work_head() - Dequeues the item at head of list * @proc: binder_proc associated with list * @list: list to dequeue head * * Removes the head of the list if there are items on the list * * Return: pointer dequeued binder_work, NULL if list was empty */ static struct binder_work *binder_dequeue_work_head( struct binder_proc *proc, struct list_head *list) { struct binder_work *w; binder_inner_proc_lock(proc); w = binder_dequeue_work_head_ilocked(list); binder_inner_proc_unlock(proc); return w; } static void binder_defer_work(struct binder_proc *proc, enum binder_deferred_state defer); static void binder_free_thread(struct binder_thread *thread); static void binder_free_proc(struct binder_proc *proc); static void binder_inc_node_tmpref_ilocked(struct binder_node *node); static bool binder_has_work_ilocked(struct binder_thread *thread, bool do_proc_work) { return thread->process_todo || thread->looper_need_return || (do_proc_work && !binder_worklist_empty_ilocked(&thread->proc->todo)); } static bool binder_has_work(struct binder_thread *thread, bool do_proc_work) { bool has_work; binder_inner_proc_lock(thread->proc); has_work = binder_has_work_ilocked(thread, do_proc_work); binder_inner_proc_unlock(thread->proc); return has_work; } static bool binder_available_for_proc_work_ilocked(struct binder_thread *thread) { return !thread->transaction_stack && binder_worklist_empty_ilocked(&thread->todo) && (thread->looper & (BINDER_LOOPER_STATE_ENTERED | BINDER_LOOPER_STATE_REGISTERED)); } static void binder_wakeup_poll_threads_ilocked(struct binder_proc *proc, bool sync) { struct rb_node *n; struct binder_thread *thread; for (n = rb_first(&proc->threads); n != NULL; n = rb_next(n)) { thread = rb_entry(n, struct binder_thread, rb_node); if (thread->looper & BINDER_LOOPER_STATE_POLL && binder_available_for_proc_work_ilocked(thread)) { if (sync) wake_up_interruptible_sync(&thread->wait); else wake_up_interruptible(&thread->wait); } } } /** * binder_select_thread_ilocked() - selects a thread for doing proc work. * @proc: process to select a thread from * * Note that calling this function moves the thread off the waiting_threads * list, so it can only be woken up by the caller of this function, or a * signal. Therefore, callers *should* always wake up the thread this function * returns. * * Return: If there's a thread currently waiting for process work, * returns that thread. Otherwise returns NULL. */ static struct binder_thread * binder_select_thread_ilocked(struct binder_proc *proc) { struct binder_thread *thread; assert_spin_locked(&proc->inner_lock); thread = list_first_entry_or_null(&proc->waiting_threads, struct binder_thread, waiting_thread_node); if (thread) list_del_init(&thread->waiting_thread_node); return thread; } /** * binder_wakeup_thread_ilocked() - wakes up a thread for doing proc work. * @proc: process to wake up a thread in * @thread: specific thread to wake-up (may be NULL) * @sync: whether to do a synchronous wake-up * * This function wakes up a thread in the @proc process. * The caller may provide a specific thread to wake-up in * the @thread parameter. If @thread is NULL, this function * will wake up threads that have called poll(). * * Note that for this function to work as expected, callers * should first call binder_select_thread() to find a thread * to handle the work (if they don't have a thread already), * and pass the result into the @thread parameter. */ static void binder_wakeup_thread_ilocked(struct binder_proc *proc, struct binder_thread *thread, bool sync) { assert_spin_locked(&proc->inner_lock); if (thread) { if (sync) wake_up_interruptible_sync(&thread->wait); else wake_up_interruptible(&thread->wait); return; } /* Didn't find a thread waiting for proc work; this can happen * in two scenarios: * 1. All threads are busy handling transactions * In that case, one of those threads should call back into * the kernel driver soon and pick up this work. * 2. Threads are using the (e)poll interface, in which case * they may be blocked on the waitqueue without having been * added to waiting_threads. For this case, we just iterate * over all threads not handling transaction work, and * wake them all up. We wake all because we don't know whether * a thread that called into (e)poll is handling non-binder * work currently. */ binder_wakeup_poll_threads_ilocked(proc, sync); } static void binder_wakeup_proc_ilocked(struct binder_proc *proc) { struct binder_thread *thread = binder_select_thread_ilocked(proc); binder_wakeup_thread_ilocked(proc, thread, /* sync = */false); } static void binder_set_nice(long nice) { long min_nice; if (can_nice(current, nice)) { set_user_nice(current, nice); return; } min_nice = rlimit_to_nice(rlimit(RLIMIT_NICE)); binder_debug(BINDER_DEBUG_PRIORITY_CAP, "%d: nice value %ld not allowed use %ld instead\n", current->pid, nice, min_nice); set_user_nice(current, min_nice); if (min_nice <= MAX_NICE) return; binder_user_error("%d RLIMIT_NICE not set\n", current->pid); } static struct binder_node *binder_get_node_ilocked(struct binder_proc *proc, binder_uintptr_t ptr) { struct rb_node *n = proc->nodes.rb_node; struct binder_node *node; assert_spin_locked(&proc->inner_lock); while (n) { node = rb_entry(n, struct binder_node, rb_node); if (ptr < node->ptr) n = n->rb_left; else if (ptr > node->ptr) n = n->rb_right; else { /* * take an implicit weak reference * to ensure node stays alive until * call to binder_put_node() */ binder_inc_node_tmpref_ilocked(node); return node; } } return NULL; } static struct binder_node *binder_get_node(struct binder_proc *proc, binder_uintptr_t ptr) { struct binder_node *node; binder_inner_proc_lock(proc); node = binder_get_node_ilocked(proc, ptr); binder_inner_proc_unlock(proc); return node; } static struct binder_node *binder_init_node_ilocked( struct binder_proc *proc, struct binder_node *new_node, struct flat_binder_object *fp) { struct rb_node **p = &proc->nodes.rb_node; struct rb_node *parent = NULL; struct binder_node *node; binder_uintptr_t ptr = fp ? fp->binder : 0; binder_uintptr_t cookie = fp ? fp->cookie : 0; __u32 flags = fp ? fp->flags : 0; assert_spin_locked(&proc->inner_lock); while (*p) { parent = *p; node = rb_entry(parent, struct binder_node, rb_node); if (ptr < node->ptr) p = &(*p)->rb_left; else if (ptr > node->ptr) p = &(*p)->rb_right; else { /* * A matching node is already in * the rb tree. Abandon the init * and return it. */ binder_inc_node_tmpref_ilocked(node); return node; } } node = new_node; binder_stats_created(BINDER_STAT_NODE); node->tmp_refs++; rb_link_node(&node->rb_node, parent, p); rb_insert_color(&node->rb_node, &proc->nodes); node->debug_id = atomic_inc_return(&binder_last_id); node->proc = proc; node->ptr = ptr; node->cookie = cookie; node->work.type = BINDER_WORK_NODE; node->min_priority = flags & FLAT_BINDER_FLAG_PRIORITY_MASK; node->accept_fds = !!(flags & FLAT_BINDER_FLAG_ACCEPTS_FDS); spin_lock_init(&node->lock); INIT_LIST_HEAD(&node->work.entry); INIT_LIST_HEAD(&node->async_todo); binder_debug(BINDER_DEBUG_INTERNAL_REFS, "%d:%d node %d u%016llx c%016llx created\n", proc->pid, current->pid, node->debug_id, (u64)node->ptr, (u64)node->cookie); return node; } static struct binder_node *binder_new_node(struct binder_proc *proc, struct flat_binder_object *fp) { struct binder_node *node; struct binder_node *new_node = kzalloc(sizeof(*node), GFP_KERNEL); if (!new_node) return NULL; binder_inner_proc_lock(proc); node = binder_init_node_ilocked(proc, new_node, fp); binder_inner_proc_unlock(proc); if (node != new_node) /* * The node was already added by another thread */ kfree(new_node); return node; } static void binder_free_node(struct binder_node *node) { kfree(node); binder_stats_deleted(BINDER_STAT_NODE); } static int binder_inc_node_nilocked(struct binder_node *node, int strong, int internal, struct list_head *target_list) { struct binder_proc *proc = node->proc; assert_spin_locked(&node->lock); if (proc) assert_spin_locked(&proc->inner_lock); if (strong) { if (internal) { if (target_list == NULL && node->internal_strong_refs == 0 && !(node->proc && node == node->proc->context->binder_context_mgr_node && node->has_strong_ref)) { pr_err("invalid inc strong node for %d\n", node->debug_id); return -EINVAL; } node->internal_strong_refs++; } else node->local_strong_refs++; if (!node->has_strong_ref && target_list) { struct binder_thread *thread = container_of(target_list, struct binder_thread, todo); binder_dequeue_work_ilocked(&node->work); BUG_ON(&thread->todo != target_list); binder_enqueue_deferred_thread_work_ilocked(thread, &node->work); } } else { if (!internal) node->local_weak_refs++; if (!node->has_weak_ref && list_empty(&node->work.entry)) { if (target_list == NULL) { pr_err("invalid inc weak node for %d\n", node->debug_id); return -EINVAL; } /* * See comment above */ binder_enqueue_work_ilocked(&node->work, target_list); } } return 0; } static int binder_inc_node(struct binder_node *node, int strong, int internal, struct list_head *target_list) { int ret; binder_node_inner_lock(node); ret = binder_inc_node_nilocked(node, strong, internal, target_list); binder_node_inner_unlock(node); return ret; } static bool binder_dec_node_nilocked(struct binder_node *node, int strong, int internal) { struct binder_proc *proc = node->proc; assert_spin_locked(&node->lock); if (proc) assert_spin_locked(&proc->inner_lock); if (strong) { if (internal) node->internal_strong_refs--; else node->local_strong_refs--; if (node->local_strong_refs || node->internal_strong_refs) return false; } else { if (!internal) node->local_weak_refs--; if (node->local_weak_refs || node->tmp_refs || !hlist_empty(&node->refs)) return false; } if (proc && (node->has_strong_ref || node->has_weak_ref)) { if (list_empty(&node->work.entry)) { binder_enqueue_work_ilocked(&node->work, &proc->todo); binder_wakeup_proc_ilocked(proc); } } else { if (hlist_empty(&node->refs) && !node->local_strong_refs && !node->local_weak_refs && !node->tmp_refs) { if (proc) { binder_dequeue_work_ilocked(&node->work); rb_erase(&node->rb_node, &proc->nodes); binder_debug(BINDER_DEBUG_INTERNAL_REFS, "refless node %d deleted\n", node->debug_id); } else { BUG_ON(!list_empty(&node->work.entry)); spin_lock(&binder_dead_nodes_lock); /* * tmp_refs could have changed so * check it again */ if (node->tmp_refs) { spin_unlock(&binder_dead_nodes_lock); return false; } hlist_del(&node->dead_node); spin_unlock(&binder_dead_nodes_lock); binder_debug(BINDER_DEBUG_INTERNAL_REFS, "dead node %d deleted\n", node->debug_id); } return true; } } return false; } static void binder_dec_node(struct binder_node *node, int strong, int internal) { bool free_node; binder_node_inner_lock(node); free_node = binder_dec_node_nilocked(node, strong, internal); binder_node_inner_unlock(node); if (free_node) binder_free_node(node); } static void binder_inc_node_tmpref_ilocked(struct binder_node *node) { /* * No call to binder_inc_node() is needed since we * don't need to inform userspace of any changes to * tmp_refs */ node->tmp_refs++; } /** * binder_inc_node_tmpref() - take a temporary reference on node * @node: node to reference * * Take reference on node to prevent the node from being freed * while referenced only by a local variable. The inner lock is * needed to serialize with the node work on the queue (which * isn't needed after the node is dead). If the node is dead * (node->proc is NULL), use binder_dead_nodes_lock to protect * node->tmp_refs against dead-node-only cases where the node * lock cannot be acquired (eg traversing the dead node list to * print nodes) */ static void binder_inc_node_tmpref(struct binder_node *node) { binder_node_lock(node); if (node->proc) binder_inner_proc_lock(node->proc); else spin_lock(&binder_dead_nodes_lock); binder_inc_node_tmpref_ilocked(node); if (node->proc) binder_inner_proc_unlock(node->proc); else spin_unlock(&binder_dead_nodes_lock); binder_node_unlock(node); } /** * binder_dec_node_tmpref() - remove a temporary reference on node * @node: node to reference * * Release temporary reference on node taken via binder_inc_node_tmpref() */ static void binder_dec_node_tmpref(struct binder_node *node) { bool free_node; binder_node_inner_lock(node); if (!node->proc) spin_lock(&binder_dead_nodes_lock); else __acquire(&binder_dead_nodes_lock); node->tmp_refs--; BUG_ON(node->tmp_refs < 0); if (!node->proc) spin_unlock(&binder_dead_nodes_lock); else __release(&binder_dead_nodes_lock); /* * Call binder_dec_node() to check if all refcounts are 0 * and cleanup is needed. Calling with strong=0 and internal=1 * causes no actual reference to be released in binder_dec_node(). * If that changes, a change is needed here too. */ free_node = binder_dec_node_nilocked(node, 0, 1); binder_node_inner_unlock(node); if (free_node) binder_free_node(node); } static void binder_put_node(struct binder_node *node) { binder_dec_node_tmpref(node); } static struct binder_ref *binder_get_ref_olocked(struct binder_proc *proc, u32 desc, bool need_strong_ref) { struct rb_node *n = proc->refs_by_desc.rb_node; struct binder_ref *ref; while (n) { ref = rb_entry(n, struct binder_ref, rb_node_desc); if (desc < ref->data.desc) { n = n->rb_left; } else if (desc > ref->data.desc) { n = n->rb_right; } else if (need_strong_ref && !ref->data.strong) { binder_user_error("tried to use weak ref as strong ref\n"); return NULL; } else { return ref; } } return NULL; } /** * binder_get_ref_for_node_olocked() - get the ref associated with given node * @proc: binder_proc that owns the ref * @node: binder_node of target * @new_ref: newly allocated binder_ref to be initialized or %NULL * * Look up the ref for the given node and return it if it exists * * If it doesn't exist and the caller provides a newly allocated * ref, initialize the fields of the newly allocated ref and insert * into the given proc rb_trees and node refs list. * * Return: the ref for node. It is possible that another thread * allocated/initialized the ref first in which case the * returned ref would be different than the passed-in * new_ref. new_ref must be kfree'd by the caller in * this case. */ static struct binder_ref *binder_get_ref_for_node_olocked( struct binder_proc *proc, struct binder_node *node, struct binder_ref *new_ref) { struct binder_context *context = proc->context; struct rb_node **p = &proc->refs_by_node.rb_node; struct rb_node *parent = NULL; struct binder_ref *ref; struct rb_node *n; while (*p) { parent = *p; ref = rb_entry(parent, struct binder_ref, rb_node_node); if (node < ref->node) p = &(*p)->rb_left; else if (node > ref->node) p = &(*p)->rb_right; else return ref; } if (!new_ref) return NULL; binder_stats_created(BINDER_STAT_REF); new_ref->data.debug_id = atomic_inc_return(&binder_last_id); new_ref->proc = proc; new_ref->node = node; rb_link_node(&new_ref->rb_node_node, parent, p); rb_insert_color(&new_ref->rb_node_node, &proc->refs_by_node); new_ref->data.desc = (node == context->binder_context_mgr_node) ? 0 : 1; for (n = rb_first(&proc->refs_by_desc); n != NULL; n = rb_next(n)) { ref = rb_entry(n, struct binder_ref, rb_node_desc); if (ref->data.desc > new_ref->data.desc) break; new_ref->data.desc = ref->data.desc + 1; } p = &proc->refs_by_desc.rb_node; while (*p) { parent = *p; ref = rb_entry(parent, struct binder_ref, rb_node_desc); if (new_ref->data.desc < ref->data.desc) p = &(*p)->rb_left; else if (new_ref->data.desc > ref->data.desc) p = &(*p)->rb_right; else BUG(); } rb_link_node(&new_ref->rb_node_desc, parent, p); rb_insert_color(&new_ref->rb_node_desc, &proc->refs_by_desc); binder_node_lock(node); hlist_add_head(&new_ref->node_entry, &node->refs); binder_debug(BINDER_DEBUG_INTERNAL_REFS, "%d new ref %d desc %d for node %d\n", proc->pid, new_ref->data.debug_id, new_ref->data.desc, node->debug_id); binder_node_unlock(node); return new_ref; } static void binder_cleanup_ref_olocked(struct binder_ref *ref) { bool delete_node = false; binder_debug(BINDER_DEBUG_INTERNAL_REFS, "%d delete ref %d desc %d for node %d\n", ref->proc->pid, ref->data.debug_id, ref->data.desc, ref->node->debug_id); rb_erase(&ref->rb_node_desc, &ref->proc->refs_by_desc); rb_erase(&ref->rb_node_node, &ref->proc->refs_by_node); binder_node_inner_lock(ref->node); if (ref->data.strong) binder_dec_node_nilocked(ref->node, 1, 1); hlist_del(&ref->node_entry); delete_node = binder_dec_node_nilocked(ref->node, 0, 1); binder_node_inner_unlock(ref->node); /* * Clear ref->node unless we want the caller to free the node */ if (!delete_node) { /* * The caller uses ref->node to determine * whether the node needs to be freed. Clear * it since the node is still alive. */ ref->node = NULL; } if (ref->death) { binder_debug(BINDER_DEBUG_DEAD_BINDER, "%d delete ref %d desc %d has death notification\n", ref->proc->pid, ref->data.debug_id, ref->data.desc); binder_dequeue_work(ref->proc, &ref->death->work); binder_stats_deleted(BINDER_STAT_DEATH); } binder_stats_deleted(BINDER_STAT_REF); } /** * binder_inc_ref_olocked() - increment the ref for given handle * @ref: ref to be incremented * @strong: if true, strong increment, else weak * @target_list: list to queue node work on * * Increment the ref. @ref->proc->outer_lock must be held on entry * * Return: 0, if successful, else errno */ static int binder_inc_ref_olocked(struct binder_ref *ref, int strong, struct list_head *target_list) { int ret; if (strong) { if (ref->data.strong == 0) { ret = binder_inc_node(ref->node, 1, 1, target_list); if (ret) return ret; } ref->data.strong++; } else { if (ref->data.weak == 0) { ret = binder_inc_node(ref->node, 0, 1, target_list); if (ret) return ret; } ref->data.weak++; } return 0; } /** * binder_dec_ref() - dec the ref for given handle * @ref: ref to be decremented * @strong: if true, strong decrement, else weak * * Decrement the ref. * * Return: true if ref is cleaned up and ready to be freed */ static bool binder_dec_ref_olocked(struct binder_ref *ref, int strong) { if (strong) { if (ref->data.strong == 0) { binder_user_error("%d invalid dec strong, ref %d desc %d s %d w %d\n", ref->proc->pid, ref->data.debug_id, ref->data.desc, ref->data.strong, ref->data.weak); return false; } ref->data.strong--; if (ref->data.strong == 0) binder_dec_node(ref->node, strong, 1); } else { if (ref->data.weak == 0) { binder_user_error("%d invalid dec weak, ref %d desc %d s %d w %d\n", ref->proc->pid, ref->data.debug_id, ref->data.desc, ref->data.strong, ref->data.weak); return false; } ref->data.weak--; } if (ref->data.strong == 0 && ref->data.weak == 0) { binder_cleanup_ref_olocked(ref); return true; } return false; } /** * binder_get_node_from_ref() - get the node from the given proc/desc * @proc: proc containing the ref * @desc: the handle associated with the ref * @need_strong_ref: if true, only return node if ref is strong * @rdata: the id/refcount data for the ref * * Given a proc and ref handle, return the associated binder_node * * Return: a binder_node or NULL if not found or not strong when strong required */ static struct binder_node *binder_get_node_from_ref( struct binder_proc *proc, u32 desc, bool need_strong_ref, struct binder_ref_data *rdata) { struct binder_node *node; struct binder_ref *ref; binder_proc_lock(proc); ref = binder_get_ref_olocked(proc, desc, need_strong_ref); if (!ref) goto err_no_ref; node = ref->node; /* * Take an implicit reference on the node to ensure * it stays alive until the call to binder_put_node() */ binder_inc_node_tmpref(node); if (rdata) *rdata = ref->data; binder_proc_unlock(proc); return node; err_no_ref: binder_proc_unlock(proc); return NULL; } /** * binder_free_ref() - free the binder_ref * @ref: ref to free * * Free the binder_ref. Free the binder_node indicated by ref->node * (if non-NULL) and the binder_ref_death indicated by ref->death. */ static void binder_free_ref(struct binder_ref *ref) { if (ref->node) binder_free_node(ref->node); kfree(ref->death); kfree(ref); } /** * binder_update_ref_for_handle() - inc/dec the ref for given handle * @proc: proc containing the ref * @desc: the handle associated with the ref * @increment: true=inc reference, false=dec reference * @strong: true=strong reference, false=weak reference * @rdata: the id/refcount data for the ref * * Given a proc and ref handle, increment or decrement the ref * according to "increment" arg. * * Return: 0 if successful, else errno */ static int binder_update_ref_for_handle(struct binder_proc *proc, uint32_t desc, bool increment, bool strong, struct binder_ref_data *rdata) { int ret = 0; struct binder_ref *ref; bool delete_ref = false; binder_proc_lock(proc); ref = binder_get_ref_olocked(proc, desc, strong); if (!ref) { ret = -EINVAL; goto err_no_ref; } if (increment) ret = binder_inc_ref_olocked(ref, strong, NULL); else delete_ref = binder_dec_ref_olocked(ref, strong); if (rdata) *rdata = ref->data; binder_proc_unlock(proc); if (delete_ref) binder_free_ref(ref); return ret; err_no_ref: binder_proc_unlock(proc); return ret; } /** * binder_dec_ref_for_handle() - dec the ref for given handle * @proc: proc containing the ref * @desc: the handle associated with the ref * @strong: true=strong reference, false=weak reference * @rdata: the id/refcount data for the ref * * Just calls binder_update_ref_for_handle() to decrement the ref. * * Return: 0 if successful, else errno */ static int binder_dec_ref_for_handle(struct binder_proc *proc, uint32_t desc, bool strong, struct binder_ref_data *rdata) { return binder_update_ref_for_handle(proc, desc, false, strong, rdata); } /** * binder_inc_ref_for_node() - increment the ref for given proc/node * @proc: proc containing the ref * @node: target node * @strong: true=strong reference, false=weak reference * @target_list: worklist to use if node is incremented * @rdata: the id/refcount data for the ref * * Given a proc and node, increment the ref. Create the ref if it * doesn't already exist * * Return: 0 if successful, else errno */ static int binder_inc_ref_for_node(struct binder_proc *proc, struct binder_node *node, bool strong, struct list_head *target_list, struct binder_ref_data *rdata) { struct binder_ref *ref; struct binder_ref *new_ref = NULL; int ret = 0; binder_proc_lock(proc); ref = binder_get_ref_for_node_olocked(proc, node, NULL); if (!ref) { binder_proc_unlock(proc); new_ref = kzalloc(sizeof(*ref), GFP_KERNEL); if (!new_ref) return -ENOMEM; binder_proc_lock(proc); ref = binder_get_ref_for_node_olocked(proc, node, new_ref); } ret = binder_inc_ref_olocked(ref, strong, target_list); *rdata = ref->data; binder_proc_unlock(proc); if (new_ref && ref != new_ref) /* * Another thread created the ref first so * free the one we allocated */ kfree(new_ref); return ret; } static void binder_pop_transaction_ilocked(struct binder_thread *target_thread, struct binder_transaction *t) { BUG_ON(!target_thread); assert_spin_locked(&target_thread->proc->inner_lock); BUG_ON(target_thread->transaction_stack != t); BUG_ON(target_thread->transaction_stack->from != target_thread); target_thread->transaction_stack = target_thread->transaction_stack->from_parent; t->from = NULL; } /** * binder_thread_dec_tmpref() - decrement thread->tmp_ref * @thread: thread to decrement * * A thread needs to be kept alive while being used to create or * handle a transaction. binder_get_txn_from() is used to safely * extract t->from from a binder_transaction and keep the thread * indicated by t->from from being freed. When done with that * binder_thread, this function is called to decrement the * tmp_ref and free if appropriate (thread has been released * and no transaction being processed by the driver) */ static void binder_thread_dec_tmpref(struct binder_thread *thread) { /* * atomic is used to protect the counter value while * it cannot reach zero or thread->is_dead is false */ binder_inner_proc_lock(thread->proc); atomic_dec(&thread->tmp_ref); if (thread->is_dead && !atomic_read(&thread->tmp_ref)) { binder_inner_proc_unlock(thread->proc); binder_free_thread(thread); return; } binder_inner_proc_unlock(thread->proc); } /** * binder_proc_dec_tmpref() - decrement proc->tmp_ref * @proc: proc to decrement * * A binder_proc needs to be kept alive while being used to create or * handle a transaction. proc->tmp_ref is incremented when * creating a new transaction or the binder_proc is currently in-use * by threads that are being released. When done with the binder_proc, * this function is called to decrement the counter and free the * proc if appropriate (proc has been released, all threads have * been released and not currenly in-use to process a transaction). */ static void binder_proc_dec_tmpref(struct binder_proc *proc) { binder_inner_proc_lock(proc); proc->tmp_ref--; if (proc->is_dead && RB_EMPTY_ROOT(&proc->threads) && !proc->tmp_ref) { binder_inner_proc_unlock(proc); binder_free_proc(proc); return; } binder_inner_proc_unlock(proc); } /** * binder_get_txn_from() - safely extract the "from" thread in transaction * @t: binder transaction for t->from * * Atomically return the "from" thread and increment the tmp_ref * count for the thread to ensure it stays alive until * binder_thread_dec_tmpref() is called. * * Return: the value of t->from */ static struct binder_thread *binder_get_txn_from( struct binder_transaction *t) { struct binder_thread *from; spin_lock(&t->lock); from = t->from; if (from) atomic_inc(&from->tmp_ref); spin_unlock(&t->lock); return from; } /** * binder_get_txn_from_and_acq_inner() - get t->from and acquire inner lock * @t: binder transaction for t->from * * Same as binder_get_txn_from() except it also acquires the proc->inner_lock * to guarantee that the thread cannot be released while operating on it. * The caller must call binder_inner_proc_unlock() to release the inner lock * as well as call binder_dec_thread_txn() to release the reference. * * Return: the value of t->from */ static struct binder_thread *binder_get_txn_from_and_acq_inner( struct binder_transaction *t) __acquires(&t->from->proc->inner_lock) { struct binder_thread *from; from = binder_get_txn_from(t); if (!from) { __acquire(&from->proc->inner_lock); return NULL; } binder_inner_proc_lock(from->proc); if (t->from) { BUG_ON(from != t->from); return from; } binder_inner_proc_unlock(from->proc); __acquire(&from->proc->inner_lock); binder_thread_dec_tmpref(from); return NULL; } /** * binder_free_txn_fixups() - free unprocessed fd fixups * @t: binder transaction for t->from * * If the transaction is being torn down prior to being * processed by the target process, free all of the * fd fixups and fput the file structs. It is safe to * call this function after the fixups have been * processed -- in that case, the list will be empty. */ static void binder_free_txn_fixups(struct binder_transaction *t) { struct binder_txn_fd_fixup *fixup, *tmp; list_for_each_entry_safe(fixup, tmp, &t->fd_fixups, fixup_entry) { fput(fixup->file); list_del(&fixup->fixup_entry); kfree(fixup); } } static void binder_free_transaction(struct binder_transaction *t) { if (t->buffer) t->buffer->transaction = NULL; binder_free_txn_fixups(t); kfree(t); binder_stats_deleted(BINDER_STAT_TRANSACTION); } static void binder_send_failed_reply(struct binder_transaction *t, uint32_t error_code) { struct binder_thread *target_thread; struct binder_transaction *next; BUG_ON(t->flags & TF_ONE_WAY); while (1) { target_thread = binder_get_txn_from_and_acq_inner(t); if (target_thread) { binder_debug(BINDER_DEBUG_FAILED_TRANSACTION, "send failed reply for transaction %d to %d:%d\n", t->debug_id, target_thread->proc->pid, target_thread->pid); binder_pop_transaction_ilocked(target_thread, t); if (target_thread->reply_error.cmd == BR_OK) { target_thread->reply_error.cmd = error_code; binder_enqueue_thread_work_ilocked( target_thread, &target_thread->reply_error.work); wake_up_interruptible(&target_thread->wait); } else { /* * Cannot get here for normal operation, but * we can if multiple synchronous transactions * are sent without blocking for responses. * Just ignore the 2nd error in this case. */ pr_warn("Unexpected reply error: %u\n", target_thread->reply_error.cmd); } binder_inner_proc_unlock(target_thread->proc); binder_thread_dec_tmpref(target_thread); binder_free_transaction(t); return; } else { __release(&target_thread->proc->inner_lock); } next = t->from_parent; binder_debug(BINDER_DEBUG_FAILED_TRANSACTION, "send failed reply for transaction %d, target dead\n", t->debug_id); binder_free_transaction(t); if (next == NULL) { binder_debug(BINDER_DEBUG_DEAD_BINDER, "reply failed, no target thread at root\n"); return; } t = next; binder_debug(BINDER_DEBUG_DEAD_BINDER, "reply failed, no target thread -- retry %d\n", t->debug_id); } } /** * binder_cleanup_transaction() - cleans up undelivered transaction * @t: transaction that needs to be cleaned up * @reason: reason the transaction wasn't delivered * @error_code: error to return to caller (if synchronous call) */ static void binder_cleanup_transaction(struct binder_transaction *t, const char *reason, uint32_t error_code) { if (t->buffer->target_node && !(t->flags & TF_ONE_WAY)) { binder_send_failed_reply(t, error_code); } else { binder_debug(BINDER_DEBUG_DEAD_TRANSACTION, "undelivered transaction %d, %s\n", t->debug_id, reason); binder_free_transaction(t); } } /** * binder_validate_object() - checks for a valid metadata object in a buffer. * @buffer: binder_buffer that we're parsing. * @offset: offset in the buffer at which to validate an object. * * Return: If there's a valid metadata object at @offset in @buffer, the * size of that object. Otherwise, it returns zero. */ static size_t binder_validate_object(struct binder_buffer *buffer, u64 offset) { /* Check if we can read a header first */ struct binder_object_header *hdr; size_t object_size = 0; if (buffer->data_size < sizeof(*hdr) || offset > buffer->data_size - sizeof(*hdr) || !IS_ALIGNED(offset, sizeof(u32))) return 0; /* Ok, now see if we can read a complete object. */ hdr = (struct binder_object_header *)(buffer->data + offset); switch (hdr->type) { case BINDER_TYPE_BINDER: case BINDER_TYPE_WEAK_BINDER: case BINDER_TYPE_HANDLE: case BINDER_TYPE_WEAK_HANDLE: object_size = sizeof(struct flat_binder_object); break; case BINDER_TYPE_FD: object_size = sizeof(struct binder_fd_object); break; case BINDER_TYPE_PTR: object_size = sizeof(struct binder_buffer_object); break; case BINDER_TYPE_FDA: object_size = sizeof(struct binder_fd_array_object); break; default: return 0; } if (offset <= buffer->data_size - object_size && buffer->data_size >= object_size) return object_size; else return 0; } /** * binder_validate_ptr() - validates binder_buffer_object in a binder_buffer. * @b: binder_buffer containing the object * @index: index in offset array at which the binder_buffer_object is * located * @start: points to the start of the offset array * @num_valid: the number of valid offsets in the offset array * * Return: If @index is within the valid range of the offset array * described by @start and @num_valid, and if there's a valid * binder_buffer_object at the offset found in index @index * of the offset array, that object is returned. Otherwise, * %NULL is returned. * Note that the offset found in index @index itself is not * verified; this function assumes that @num_valid elements * from @start were previously verified to have valid offsets. */ static struct binder_buffer_object *binder_validate_ptr(struct binder_buffer *b, binder_size_t index, binder_size_t *start, binder_size_t num_valid) { struct binder_buffer_object *buffer_obj; binder_size_t *offp; if (index >= num_valid) return NULL; offp = start + index; buffer_obj = (struct binder_buffer_object *)(b->data + *offp); if (buffer_obj->hdr.type != BINDER_TYPE_PTR) return NULL; return buffer_obj; } /** * binder_validate_fixup() - validates pointer/fd fixups happen in order. * @b: transaction buffer * @objects_start start of objects buffer * @buffer: binder_buffer_object in which to fix up * @offset: start offset in @buffer to fix up * @last_obj: last binder_buffer_object that we fixed up in * @last_min_offset: minimum fixup offset in @last_obj * * Return: %true if a fixup in buffer @buffer at offset @offset is * allowed. * * For safety reasons, we only allow fixups inside a buffer to happen * at increasing offsets; additionally, we only allow fixup on the last * buffer object that was verified, or one of its parents. * * Example of what is allowed: * * A * B (parent = A, offset = 0) * C (parent = A, offset = 16) * D (parent = C, offset = 0) * E (parent = A, offset = 32) // min_offset is 16 (C.parent_offset) * * Examples of what is not allowed: * * Decreasing offsets within the same parent: * A * C (parent = A, offset = 16) * B (parent = A, offset = 0) // decreasing offset within A * * Referring to a parent that wasn't the last object or any of its parents: * A * B (parent = A, offset = 0) * C (parent = A, offset = 0) * C (parent = A, offset = 16) * D (parent = B, offset = 0) // B is not A or any of A's parents */ static bool binder_validate_fixup(struct binder_buffer *b, binder_size_t *objects_start, struct binder_buffer_object *buffer, binder_size_t fixup_offset, struct binder_buffer_object *last_obj, binder_size_t last_min_offset) { if (!last_obj) { /* Nothing to fix up in */ return false; } while (last_obj != buffer) { /* * Safe to retrieve the parent of last_obj, since it * was already previously verified by the driver. */ if ((last_obj->flags & BINDER_BUFFER_FLAG_HAS_PARENT) == 0) return false; last_min_offset = last_obj->parent_offset + sizeof(uintptr_t); last_obj = (struct binder_buffer_object *) (b->data + *(objects_start + last_obj->parent)); } return (fixup_offset >= last_min_offset); } static void binder_transaction_buffer_release(struct binder_proc *proc, struct binder_buffer *buffer, binder_size_t *failed_at) { binder_size_t *offp, *off_start, *off_end; int debug_id = buffer->debug_id; binder_debug(BINDER_DEBUG_TRANSACTION, "%d buffer release %d, size %zd-%zd, failed at %pK\n", proc->pid, buffer->debug_id, buffer->data_size, buffer->offsets_size, failed_at); if (buffer->target_node) binder_dec_node(buffer->target_node, 1, 0); off_start = (binder_size_t *)(buffer->data + ALIGN(buffer->data_size, sizeof(void *))); if (failed_at) off_end = failed_at; else off_end = (void *)off_start + buffer->offsets_size; for (offp = off_start; offp < off_end; offp++) { struct binder_object_header *hdr; size_t object_size = binder_validate_object(buffer, *offp); if (object_size == 0) { pr_err("transaction release %d bad object at offset %lld, size %zd\n", debug_id, (u64)*offp, buffer->data_size); continue; } hdr = (struct binder_object_header *)(buffer->data + *offp); switch (hdr->type) { case BINDER_TYPE_BINDER: case BINDER_TYPE_WEAK_BINDER: { struct flat_binder_object *fp; struct binder_node *node; fp = to_flat_binder_object(hdr); node = binder_get_node(proc, fp->binder); if (node == NULL) { pr_err("transaction release %d bad node %016llx\n", debug_id, (u64)fp->binder); break; } binder_debug(BINDER_DEBUG_TRANSACTION, " node %d u%016llx\n", node->debug_id, (u64)node->ptr); binder_dec_node(node, hdr->type == BINDER_TYPE_BINDER, 0); binder_put_node(node); } break; case BINDER_TYPE_HANDLE: case BINDER_TYPE_WEAK_HANDLE: { struct flat_binder_object *fp; struct binder_ref_data rdata; int ret; fp = to_flat_binder_object(hdr); ret = binder_dec_ref_for_handle(proc, fp->handle, hdr->type == BINDER_TYPE_HANDLE, &rdata); if (ret) { pr_err("transaction release %d bad handle %d, ret = %d\n", debug_id, fp->handle, ret); break; } binder_debug(BINDER_DEBUG_TRANSACTION, " ref %d desc %d\n", rdata.debug_id, rdata.desc); } break; case BINDER_TYPE_FD: { /* * No need to close the file here since user-space * closes it for for successfully delivered * transactions. For transactions that weren't * delivered, the new fd was never allocated so * there is no need to close and the fput on the * file is done when the transaction is torn * down. */ WARN_ON(failed_at && proc->tsk == current->group_leader); } break; case BINDER_TYPE_PTR: /* * Nothing to do here, this will get cleaned up when the * transaction buffer gets freed */ break; case BINDER_TYPE_FDA: { struct binder_fd_array_object *fda; struct binder_buffer_object *parent; uintptr_t parent_buffer; u32 *fd_array; size_t fd_index; binder_size_t fd_buf_size; if (proc->tsk != current->group_leader) { /* * Nothing to do if running in sender context * The fd fixups have not been applied so no * fds need to be closed. */ continue; } fda = to_binder_fd_array_object(hdr); parent = binder_validate_ptr(buffer, fda->parent, off_start, offp - off_start); if (!parent) { pr_err("transaction release %d bad parent offset\n", debug_id); continue; } /* * Since the parent was already fixed up, convert it * back to kernel address space to access it */ parent_buffer = parent->buffer - binder_alloc_get_user_buffer_offset( &proc->alloc); fd_buf_size = sizeof(u32) * fda->num_fds; if (fda->num_fds >= SIZE_MAX / sizeof(u32)) { pr_err("transaction release %d invalid number of fds (%lld)\n", debug_id, (u64)fda->num_fds); continue; } if (fd_buf_size > parent->length || fda->parent_offset > parent->length - fd_buf_size) { /* No space for all file descriptors here. */ pr_err("transaction release %d not enough space for %lld fds in buffer\n", debug_id, (u64)fda->num_fds); continue; } fd_array = (u32 *)(parent_buffer + (uintptr_t)fda->parent_offset); for (fd_index = 0; fd_index < fda->num_fds; fd_index++) ksys_close(fd_array[fd_index]); } break; default: pr_err("transaction release %d bad object type %x\n", debug_id, hdr->type); break; } } } static int binder_translate_binder(struct flat_binder_object *fp, struct binder_transaction *t, struct binder_thread *thread) { struct binder_node *node; struct binder_proc *proc = thread->proc; struct binder_proc *target_proc = t->to_proc; struct binder_ref_data rdata; int ret = 0; node = binder_get_node(proc, fp->binder); if (!node) { node = binder_new_node(proc, fp); if (!node) return -ENOMEM; } if (fp->cookie != node->cookie) { binder_user_error("%d:%d sending u%016llx node %d, cookie mismatch %016llx != %016llx\n", proc->pid, thread->pid, (u64)fp->binder, node->debug_id, (u64)fp->cookie, (u64)node->cookie); ret = -EINVAL; goto done; } if (security_binder_transfer_binder(proc->tsk, target_proc->tsk)) { ret = -EPERM; goto done; } ret = binder_inc_ref_for_node(target_proc, node, fp->hdr.type == BINDER_TYPE_BINDER, &thread->todo, &rdata); if (ret) goto done; if (fp->hdr.type == BINDER_TYPE_BINDER) fp->hdr.type = BINDER_TYPE_HANDLE; else fp->hdr.type = BINDER_TYPE_WEAK_HANDLE; fp->binder = 0; fp->handle = rdata.desc; fp->cookie = 0; trace_binder_transaction_node_to_ref(t, node, &rdata); binder_debug(BINDER_DEBUG_TRANSACTION, " node %d u%016llx -> ref %d desc %d\n", node->debug_id, (u64)node->ptr, rdata.debug_id, rdata.desc); done: binder_put_node(node); return ret; } static int binder_translate_handle(struct flat_binder_object *fp, struct binder_transaction *t, struct binder_thread *thread) { struct binder_proc *proc = thread->proc; struct binder_proc *target_proc = t->to_proc; struct binder_node *node; struct binder_ref_data src_rdata; int ret = 0; node = binder_get_node_from_ref(proc, fp->handle, fp->hdr.type == BINDER_TYPE_HANDLE, &src_rdata); if (!node) { binder_user_error("%d:%d got transaction with invalid handle, %d\n", proc->pid, thread->pid, fp->handle); return -EINVAL; } if (security_binder_transfer_binder(proc->tsk, target_proc->tsk)) { ret = -EPERM; goto done; } binder_node_lock(node); if (node->proc == target_proc) { if (fp->hdr.type == BINDER_TYPE_HANDLE) fp->hdr.type = BINDER_TYPE_BINDER; else fp->hdr.type = BINDER_TYPE_WEAK_BINDER; fp->binder = node->ptr; fp->cookie = node->cookie; if (node->proc) binder_inner_proc_lock(node->proc); else __acquire(&node->proc->inner_lock); binder_inc_node_nilocked(node, fp->hdr.type == BINDER_TYPE_BINDER, 0, NULL); if (node->proc) binder_inner_proc_unlock(node->proc); else __release(&node->proc->inner_lock); trace_binder_transaction_ref_to_node(t, node, &src_rdata); binder_debug(BINDER_DEBUG_TRANSACTION, " ref %d desc %d -> node %d u%016llx\n", src_rdata.debug_id, src_rdata.desc, node->debug_id, (u64)node->ptr); binder_node_unlock(node); } else { struct binder_ref_data dest_rdata; binder_node_unlock(node); ret = binder_inc_ref_for_node(target_proc, node, fp->hdr.type == BINDER_TYPE_HANDLE, NULL, &dest_rdata); if (ret) goto done; fp->binder = 0; fp->handle = dest_rdata.desc; fp->cookie = 0; trace_binder_transaction_ref_to_ref(t, node, &src_rdata, &dest_rdata); binder_debug(BINDER_DEBUG_TRANSACTION, " ref %d desc %d -> ref %d desc %d (node %d)\n", src_rdata.debug_id, src_rdata.desc, dest_rdata.debug_id, dest_rdata.desc, node->debug_id); } done: binder_put_node(node); return ret; } static int binder_translate_fd(u32 *fdp, struct binder_transaction *t, struct binder_thread *thread, struct binder_transaction *in_reply_to) { struct binder_proc *proc = thread->proc; struct binder_proc *target_proc = t->to_proc; struct binder_txn_fd_fixup *fixup; struct file *file; int ret = 0; bool target_allows_fd; int fd = *fdp; if (in_reply_to) target_allows_fd = !!(in_reply_to->flags & TF_ACCEPT_FDS); else target_allows_fd = t->buffer->target_node->accept_fds; if (!target_allows_fd) { binder_user_error("%d:%d got %s with fd, %d, but target does not allow fds\n", proc->pid, thread->pid, in_reply_to ? "reply" : "transaction", fd); ret = -EPERM; goto err_fd_not_accepted; } file = fget(fd); if (!file) { binder_user_error("%d:%d got transaction with invalid fd, %d\n", proc->pid, thread->pid, fd); ret = -EBADF; goto err_fget; } ret = security_binder_transfer_file(proc->tsk, target_proc->tsk, file); if (ret < 0) { ret = -EPERM; goto err_security; } /* * Add fixup record for this transaction. The allocation * of the fd in the target needs to be done from a * target thread. */ fixup = kzalloc(sizeof(*fixup), GFP_KERNEL); if (!fixup) { ret = -ENOMEM; goto err_alloc; } fixup->file = file; fixup->offset = (uintptr_t)fdp - (uintptr_t)t->buffer->data; trace_binder_transaction_fd_send(t, fd, fixup->offset); list_add_tail(&fixup->fixup_entry, &t->fd_fixups); return ret; err_alloc: err_security: fput(file); err_fget: err_fd_not_accepted: return ret; } static int binder_translate_fd_array(struct binder_fd_array_object *fda, struct binder_buffer_object *parent, struct binder_transaction *t, struct binder_thread *thread, struct binder_transaction *in_reply_to) { binder_size_t fdi, fd_buf_size; uintptr_t parent_buffer; u32 *fd_array; struct binder_proc *proc = thread->proc; struct binder_proc *target_proc = t->to_proc; fd_buf_size = sizeof(u32) * fda->num_fds; if (fda->num_fds >= SIZE_MAX / sizeof(u32)) { binder_user_error("%d:%d got transaction with invalid number of fds (%lld)\n", proc->pid, thread->pid, (u64)fda->num_fds); return -EINVAL; } if (fd_buf_size > parent->length || fda->parent_offset > parent->length - fd_buf_size) { /* No space for all file descriptors here. */ binder_user_error("%d:%d not enough space to store %lld fds in buffer\n", proc->pid, thread->pid, (u64)fda->num_fds); return -EINVAL; } /* * Since the parent was already fixed up, convert it * back to the kernel address space to access it */ parent_buffer = parent->buffer - binder_alloc_get_user_buffer_offset(&target_proc->alloc); fd_array = (u32 *)(parent_buffer + (uintptr_t)fda->parent_offset); if (!IS_ALIGNED((unsigned long)fd_array, sizeof(u32))) { binder_user_error("%d:%d parent offset not aligned correctly.\n", proc->pid, thread->pid); return -EINVAL; } for (fdi = 0; fdi < fda->num_fds; fdi++) { int ret = binder_translate_fd(&fd_array[fdi], t, thread, in_reply_to); if (ret < 0) return ret; } return 0; } static int binder_fixup_parent(struct binder_transaction *t, struct binder_thread *thread, struct binder_buffer_object *bp, binder_size_t *off_start, binder_size_t num_valid, struct binder_buffer_object *last_fixup_obj, binder_size_t last_fixup_min_off) { struct binder_buffer_object *parent; u8 *parent_buffer; struct binder_buffer *b = t->buffer; struct binder_proc *proc = thread->proc; struct binder_proc *target_proc = t->to_proc; if (!(bp->flags & BINDER_BUFFER_FLAG_HAS_PARENT)) return 0; parent = binder_validate_ptr(b, bp->parent, off_start, num_valid); if (!parent) { binder_user_error("%d:%d got transaction with invalid parent offset or type\n", proc->pid, thread->pid); return -EINVAL; } if (!binder_validate_fixup(b, off_start, parent, bp->parent_offset, last_fixup_obj, last_fixup_min_off)) { binder_user_error("%d:%d got transaction with out-of-order buffer fixup\n", proc->pid, thread->pid); return -EINVAL; } if (parent->length < sizeof(binder_uintptr_t) || bp->parent_offset > parent->length - sizeof(binder_uintptr_t)) { /* No space for a pointer here! */ binder_user_error("%d:%d got transaction with invalid parent offset\n", proc->pid, thread->pid); return -EINVAL; } parent_buffer = (u8 *)((uintptr_t)parent->buffer - binder_alloc_get_user_buffer_offset( &target_proc->alloc)); *(binder_uintptr_t *)(parent_buffer + bp->parent_offset) = bp->buffer; return 0; } /** * binder_proc_transaction() - sends a transaction to a process and wakes it up * @t: transaction to send * @proc: process to send the transaction to * @thread: thread in @proc to send the transaction to (may be NULL) * * This function queues a transaction to the specified process. It will try * to find a thread in the target process to handle the transaction and * wake it up. If no thread is found, the work is queued to the proc * waitqueue. * * If the @thread parameter is not NULL, the transaction is always queued * to the waitlist of that specific thread. * * Return: true if the transactions was successfully queued * false if the target process or thread is dead */ static bool binder_proc_transaction(struct binder_transaction *t, struct binder_proc *proc, struct binder_thread *thread) { struct binder_node *node = t->buffer->target_node; bool oneway = !!(t->flags & TF_ONE_WAY); bool pending_async = false; BUG_ON(!node); binder_node_lock(node); if (oneway) { BUG_ON(thread); if (node->has_async_transaction) { pending_async = true; } else { node->has_async_transaction = true; } } binder_inner_proc_lock(proc); if (proc->is_dead || (thread && thread->is_dead)) { binder_inner_proc_unlock(proc); binder_node_unlock(node); return false; } if (!thread && !pending_async) thread = binder_select_thread_ilocked(proc); if (thread) binder_enqueue_thread_work_ilocked(thread, &t->work); else if (!pending_async) binder_enqueue_work_ilocked(&t->work, &proc->todo); else binder_enqueue_work_ilocked(&t->work, &node->async_todo); if (!pending_async) binder_wakeup_thread_ilocked(proc, thread, !oneway /* sync */); binder_inner_proc_unlock(proc); binder_node_unlock(node); return true; } /** * binder_get_node_refs_for_txn() - Get required refs on node for txn * @node: struct binder_node for which to get refs * @proc: returns @node->proc if valid * @error: if no @proc then returns BR_DEAD_REPLY * * User-space normally keeps the node alive when creating a transaction * since it has a reference to the target. The local strong ref keeps it * alive if the sending process dies before the target process processes * the transaction. If the source process is malicious or has a reference * counting bug, relying on the local strong ref can fail. * * Since user-space can cause the local strong ref to go away, we also take * a tmpref on the node to ensure it survives while we are constructing * the transaction. We also need a tmpref on the proc while we are * constructing the transaction, so we take that here as well. * * Return: The target_node with refs taken or NULL if no @node->proc is NULL. * Also sets @proc if valid. If the @node->proc is NULL indicating that the * target proc has died, @error is set to BR_DEAD_REPLY */ static struct binder_node *binder_get_node_refs_for_txn( struct binder_node *node, struct binder_proc **procp, uint32_t *error) { struct binder_node *target_node = NULL; binder_node_inner_lock(node); if (node->proc) { target_node = node; binder_inc_node_nilocked(node, 1, 0, NULL); binder_inc_node_tmpref_ilocked(node); node->proc->tmp_ref++; *procp = node->proc; } else *error = BR_DEAD_REPLY; binder_node_inner_unlock(node); return target_node; } static void binder_transaction(struct binder_proc *proc, struct binder_thread *thread, struct binder_transaction_data *tr, int reply, binder_size_t extra_buffers_size) { int ret; struct binder_transaction *t; struct binder_work *w; struct binder_work *tcomplete; binder_size_t *offp, *off_end, *off_start; binder_size_t off_min; u8 *sg_bufp, *sg_buf_end; struct binder_proc *target_proc = NULL; struct binder_thread *target_thread = NULL; struct binder_node *target_node = NULL; struct binder_transaction *in_reply_to = NULL; struct binder_transaction_log_entry *e; uint32_t return_error = 0; uint32_t return_error_param = 0; uint32_t return_error_line = 0; struct binder_buffer_object *last_fixup_obj = NULL; binder_size_t last_fixup_min_off = 0; struct binder_context *context = proc->context; int t_debug_id = atomic_inc_return(&binder_last_id); e = binder_transaction_log_add(&binder_transaction_log); e->debug_id = t_debug_id; e->call_type = reply ? 2 : !!(tr->flags & TF_ONE_WAY); e->from_proc = proc->pid; e->from_thread = thread->pid; e->target_handle = tr->target.handle; e->data_size = tr->data_size; e->offsets_size = tr->offsets_size; e->context_name = proc->context->name; if (reply) { binder_inner_proc_lock(proc); in_reply_to = thread->transaction_stack; if (in_reply_to == NULL) { binder_inner_proc_unlock(proc); binder_user_error("%d:%d got reply transaction with no transaction stack\n", proc->pid, thread->pid); return_error = BR_FAILED_REPLY; return_error_param = -EPROTO; return_error_line = __LINE__; goto err_empty_call_stack; } if (in_reply_to->to_thread != thread) { spin_lock(&in_reply_to->lock); binder_user_error("%d:%d got reply transaction with bad transaction stack, transaction %d has target %d:%d\n", proc->pid, thread->pid, in_reply_to->debug_id, in_reply_to->to_proc ? in_reply_to->to_proc->pid : 0, in_reply_to->to_thread ? in_reply_to->to_thread->pid : 0); spin_unlock(&in_reply_to->lock); binder_inner_proc_unlock(proc); return_error = BR_FAILED_REPLY; return_error_param = -EPROTO; return_error_line = __LINE__; in_reply_to = NULL; goto err_bad_call_stack; } thread->transaction_stack = in_reply_to->to_parent; binder_inner_proc_unlock(proc); binder_set_nice(in_reply_to->saved_priority); target_thread = binder_get_txn_from_and_acq_inner(in_reply_to); if (target_thread == NULL) { /* annotation for sparse */ __release(&target_thread->proc->inner_lock); return_error = BR_DEAD_REPLY; return_error_line = __LINE__; goto err_dead_binder; } if (target_thread->transaction_stack != in_reply_to) { binder_user_error("%d:%d got reply transaction with bad target transaction stack %d, expected %d\n", proc->pid, thread->pid, target_thread->transaction_stack ? target_thread->transaction_stack->debug_id : 0, in_reply_to->debug_id); binder_inner_proc_unlock(target_thread->proc); return_error = BR_FAILED_REPLY; return_error_param = -EPROTO; return_error_line = __LINE__; in_reply_to = NULL; target_thread = NULL; goto err_dead_binder; } target_proc = target_thread->proc; target_proc->tmp_ref++; binder_inner_proc_unlock(target_thread->proc); } else { if (tr->target.handle) { struct binder_ref *ref; /* * There must already be a strong ref * on this node. If so, do a strong * increment on the node to ensure it * stays alive until the transaction is * done. */ binder_proc_lock(proc); ref = binder_get_ref_olocked(proc, tr->target.handle, true); if (ref) { target_node = binder_get_node_refs_for_txn( ref->node, &target_proc, &return_error); } else { binder_user_error("%d:%d got transaction to invalid handle\n", proc->pid, thread->pid); return_error = BR_FAILED_REPLY; } binder_proc_unlock(proc); } else { mutex_lock(&context->context_mgr_node_lock); target_node = context->binder_context_mgr_node; if (target_node) target_node = binder_get_node_refs_for_txn( target_node, &target_proc, &return_error); else return_error = BR_DEAD_REPLY; mutex_unlock(&context->context_mgr_node_lock); if (target_node && target_proc == proc) { binder_user_error("%d:%d got transaction to context manager from process owning it\n", proc->pid, thread->pid); return_error = BR_FAILED_REPLY; return_error_param = -EINVAL; return_error_line = __LINE__; goto err_invalid_target_handle; } } if (!target_node) { /* * return_error is set above */ return_error_param = -EINVAL; return_error_line = __LINE__; goto err_dead_binder; } e->to_node = target_node->debug_id; if (security_binder_transaction(proc->tsk, target_proc->tsk) < 0) { return_error = BR_FAILED_REPLY; return_error_param = -EPERM; return_error_line = __LINE__; goto err_invalid_target_handle; } binder_inner_proc_lock(proc); w = list_first_entry_or_null(&thread->todo, struct binder_work, entry); if (!(tr->flags & TF_ONE_WAY) && w && w->type == BINDER_WORK_TRANSACTION) { /* * Do not allow new outgoing transaction from a * thread that has a transaction at the head of * its todo list. Only need to check the head * because binder_select_thread_ilocked picks a * thread from proc->waiting_threads to enqueue * the transaction, and nothing is queued to the * todo list while the thread is on waiting_threads. */ binder_user_error("%d:%d new transaction not allowed when there is a transaction on thread todo\n", proc->pid, thread->pid); binder_inner_proc_unlock(proc); return_error = BR_FAILED_REPLY; return_error_param = -EPROTO; return_error_line = __LINE__; goto err_bad_todo_list; } if (!(tr->flags & TF_ONE_WAY) && thread->transaction_stack) { struct binder_transaction *tmp; tmp = thread->transaction_stack; if (tmp->to_thread != thread) { spin_lock(&tmp->lock); binder_user_error("%d:%d got new transaction with bad transaction stack, transaction %d has target %d:%d\n", proc->pid, thread->pid, tmp->debug_id, tmp->to_proc ? tmp->to_proc->pid : 0, tmp->to_thread ? tmp->to_thread->pid : 0); spin_unlock(&tmp->lock); binder_inner_proc_unlock(proc); return_error = BR_FAILED_REPLY; return_error_param = -EPROTO; return_error_line = __LINE__; goto err_bad_call_stack; } while (tmp) { struct binder_thread *from; spin_lock(&tmp->lock); from = tmp->from; if (from && from->proc == target_proc) { atomic_inc(&from->tmp_ref); target_thread = from; spin_unlock(&tmp->lock); break; } spin_unlock(&tmp->lock); tmp = tmp->from_parent; } } binder_inner_proc_unlock(proc); } if (target_thread) e->to_thread = target_thread->pid; e->to_proc = target_proc->pid; /* TODO: reuse incoming transaction for reply */ t = kzalloc(sizeof(*t), GFP_KERNEL); if (t == NULL) { return_error = BR_FAILED_REPLY; return_error_param = -ENOMEM; return_error_line = __LINE__; goto err_alloc_t_failed; } INIT_LIST_HEAD(&t->fd_fixups); binder_stats_created(BINDER_STAT_TRANSACTION); spin_lock_init(&t->lock); tcomplete = kzalloc(sizeof(*tcomplete), GFP_KERNEL); if (tcomplete == NULL) { return_error = BR_FAILED_REPLY; return_error_param = -ENOMEM; return_error_line = __LINE__; goto err_alloc_tcomplete_failed; } binder_stats_created(BINDER_STAT_TRANSACTION_COMPLETE); t->debug_id = t_debug_id; if (reply) binder_debug(BINDER_DEBUG_TRANSACTION, "%d:%d BC_REPLY %d -> %d:%d, data %016llx-%016llx size %lld-%lld-%lld\n", proc->pid, thread->pid, t->debug_id, target_proc->pid, target_thread->pid, (u64)tr->data.ptr.buffer, (u64)tr->data.ptr.offsets, (u64)tr->data_size, (u64)tr->offsets_size, (u64)extra_buffers_size); else binder_debug(BINDER_DEBUG_TRANSACTION, "%d:%d BC_TRANSACTION %d -> %d - node %d, data %016llx-%016llx size %lld-%lld-%lld\n", proc->pid, thread->pid, t->debug_id, target_proc->pid, target_node->debug_id, (u64)tr->data.ptr.buffer, (u64)tr->data.ptr.offsets, (u64)tr->data_size, (u64)tr->offsets_size, (u64)extra_buffers_size); if (!reply && !(tr->flags & TF_ONE_WAY)) t->from = thread; else t->from = NULL; t->sender_euid = task_euid(proc->tsk); t->to_proc = target_proc; t->to_thread = target_thread; t->code = tr->code; t->flags = tr->flags; t->priority = task_nice(current); trace_binder_transaction(reply, t, target_node); t->buffer = binder_alloc_new_buf(&target_proc->alloc, tr->data_size, tr->offsets_size, extra_buffers_size, !reply && (t->flags & TF_ONE_WAY)); if (IS_ERR(t->buffer)) { /* * -ESRCH indicates VMA cleared. The target is dying. */ return_error_param = PTR_ERR(t->buffer); return_error = return_error_param == -ESRCH ? BR_DEAD_REPLY : BR_FAILED_REPLY; return_error_line = __LINE__; t->buffer = NULL; goto err_binder_alloc_buf_failed; } t->buffer->debug_id = t->debug_id; t->buffer->transaction = t; t->buffer->target_node = target_node; trace_binder_transaction_alloc_buf(t->buffer); off_start = (binder_size_t *)(t->buffer->data + ALIGN(tr->data_size, sizeof(void *))); offp = off_start; if (copy_from_user(t->buffer->data, (const void __user *)(uintptr_t) tr->data.ptr.buffer, tr->data_size)) { binder_user_error("%d:%d got transaction with invalid data ptr\n", proc->pid, thread->pid); return_error = BR_FAILED_REPLY; return_error_param = -EFAULT; return_error_line = __LINE__; goto err_copy_data_failed; } if (copy_from_user(offp, (const void __user *)(uintptr_t) tr->data.ptr.offsets, tr->offsets_size)) { binder_user_error("%d:%d got transaction with invalid offsets ptr\n", proc->pid, thread->pid); return_error = BR_FAILED_REPLY; return_error_param = -EFAULT; return_error_line = __LINE__; goto err_copy_data_failed; } if (!IS_ALIGNED(tr->offsets_size, sizeof(binder_size_t))) { binder_user_error("%d:%d got transaction with invalid offsets size, %lld\n", proc->pid, thread->pid, (u64)tr->offsets_size); return_error = BR_FAILED_REPLY; return_error_param = -EINVAL; return_error_line = __LINE__; goto err_bad_offset; } if (!IS_ALIGNED(extra_buffers_size, sizeof(u64))) { binder_user_error("%d:%d got transaction with unaligned buffers size, %lld\n", proc->pid, thread->pid, (u64)extra_buffers_size); return_error = BR_FAILED_REPLY; return_error_param = -EINVAL; return_error_line = __LINE__; goto err_bad_offset; } off_end = (void *)off_start + tr->offsets_size; sg_bufp = (u8 *)(PTR_ALIGN(off_end, sizeof(void *))); sg_buf_end = sg_bufp + extra_buffers_size; off_min = 0; for (; offp < off_end; offp++) { struct binder_object_header *hdr; size_t object_size = binder_validate_object(t->buffer, *offp); if (object_size == 0 || *offp < off_min) { binder_user_error("%d:%d got transaction with invalid offset (%lld, min %lld max %lld) or object.\n", proc->pid, thread->pid, (u64)*offp, (u64)off_min, (u64)t->buffer->data_size); return_error = BR_FAILED_REPLY; return_error_param = -EINVAL; return_error_line = __LINE__; goto err_bad_offset; } hdr = (struct binder_object_header *)(t->buffer->data + *offp); off_min = *offp + object_size; switch (hdr->type) { case BINDER_TYPE_BINDER: case BINDER_TYPE_WEAK_BINDER: { struct flat_binder_object *fp; fp = to_flat_binder_object(hdr); ret = binder_translate_binder(fp, t, thread); if (ret < 0) { return_error = BR_FAILED_REPLY; return_error_param = ret; return_error_line = __LINE__; goto err_translate_failed; } } break; case BINDER_TYPE_HANDLE: case BINDER_TYPE_WEAK_HANDLE: { struct flat_binder_object *fp; fp = to_flat_binder_object(hdr); ret = binder_translate_handle(fp, t, thread); if (ret < 0) { return_error = BR_FAILED_REPLY; return_error_param = ret; return_error_line = __LINE__; goto err_translate_failed; } } break; case BINDER_TYPE_FD: { struct binder_fd_object *fp = to_binder_fd_object(hdr); int ret = binder_translate_fd(&fp->fd, t, thread, in_reply_to); if (ret < 0) { return_error = BR_FAILED_REPLY; return_error_param = ret; return_error_line = __LINE__; goto err_translate_failed; } fp->pad_binder = 0; } break; case BINDER_TYPE_FDA: { struct binder_fd_array_object *fda = to_binder_fd_array_object(hdr); struct binder_buffer_object *parent = binder_validate_ptr(t->buffer, fda->parent, off_start, offp - off_start); if (!parent) { binder_user_error("%d:%d got transaction with invalid parent offset or type\n", proc->pid, thread->pid); return_error = BR_FAILED_REPLY; return_error_param = -EINVAL; return_error_line = __LINE__; goto err_bad_parent; } if (!binder_validate_fixup(t->buffer, off_start, parent, fda->parent_offset, last_fixup_obj, last_fixup_min_off)) { binder_user_error("%d:%d got transaction with out-of-order buffer fixup\n", proc->pid, thread->pid); return_error = BR_FAILED_REPLY; return_error_param = -EINVAL; return_error_line = __LINE__; goto err_bad_parent; } ret = binder_translate_fd_array(fda, parent, t, thread, in_reply_to); if (ret < 0) { return_error = BR_FAILED_REPLY; return_error_param = ret; return_error_line = __LINE__; goto err_translate_failed; } last_fixup_obj = parent; last_fixup_min_off = fda->parent_offset + sizeof(u32) * fda->num_fds; } break; case BINDER_TYPE_PTR: { struct binder_buffer_object *bp = to_binder_buffer_object(hdr); size_t buf_left = sg_buf_end - sg_bufp; if (bp->length > buf_left) { binder_user_error("%d:%d got transaction with too large buffer\n", proc->pid, thread->pid); return_error = BR_FAILED_REPLY; return_error_param = -EINVAL; return_error_line = __LINE__; goto err_bad_offset; } if (copy_from_user(sg_bufp, (const void __user *)(uintptr_t) bp->buffer, bp->length)) { binder_user_error("%d:%d got transaction with invalid offsets ptr\n", proc->pid, thread->pid); return_error_param = -EFAULT; return_error = BR_FAILED_REPLY; return_error_line = __LINE__; goto err_copy_data_failed; } /* Fixup buffer pointer to target proc address space */ bp->buffer = (uintptr_t)sg_bufp + binder_alloc_get_user_buffer_offset( &target_proc->alloc); sg_bufp += ALIGN(bp->length, sizeof(u64)); ret = binder_fixup_parent(t, thread, bp, off_start, offp - off_start, last_fixup_obj, last_fixup_min_off); if (ret < 0) { return_error = BR_FAILED_REPLY; return_error_param = ret; return_error_line = __LINE__; goto err_translate_failed; } last_fixup_obj = bp; last_fixup_min_off = 0; } break; default: binder_user_error("%d:%d got transaction with invalid object type, %x\n", proc->pid, thread->pid, hdr->type); return_error = BR_FAILED_REPLY; return_error_param = -EINVAL; return_error_line = __LINE__; goto err_bad_object_type; } } tcomplete->type = BINDER_WORK_TRANSACTION_COMPLETE; t->work.type = BINDER_WORK_TRANSACTION; if (reply) { binder_enqueue_thread_work(thread, tcomplete); binder_inner_proc_lock(target_proc); if (target_thread->is_dead) { binder_inner_proc_unlock(target_proc); goto err_dead_proc_or_thread; } BUG_ON(t->buffer->async_transaction != 0); binder_pop_transaction_ilocked(target_thread, in_reply_to); binder_enqueue_thread_work_ilocked(target_thread, &t->work); binder_inner_proc_unlock(target_proc); wake_up_interruptible_sync(&target_thread->wait); binder_free_transaction(in_reply_to); } else if (!(t->flags & TF_ONE_WAY)) { BUG_ON(t->buffer->async_transaction != 0); binder_inner_proc_lock(proc); /* * Defer the TRANSACTION_COMPLETE, so we don't return to * userspace immediately; this allows the target process to * immediately start processing this transaction, reducing * latency. We will then return the TRANSACTION_COMPLETE when * the target replies (or there is an error). */ binder_enqueue_deferred_thread_work_ilocked(thread, tcomplete); t->need_reply = 1; t->from_parent = thread->transaction_stack; thread->transaction_stack = t; binder_inner_proc_unlock(proc); if (!binder_proc_transaction(t, target_proc, target_thread)) { binder_inner_proc_lock(proc); binder_pop_transaction_ilocked(thread, t); binder_inner_proc_unlock(proc); goto err_dead_proc_or_thread; } } else { BUG_ON(target_node == NULL); BUG_ON(t->buffer->async_transaction != 1); binder_enqueue_thread_work(thread, tcomplete); if (!binder_proc_transaction(t, target_proc, NULL)) goto err_dead_proc_or_thread; } if (target_thread) binder_thread_dec_tmpref(target_thread); binder_proc_dec_tmpref(target_proc); if (target_node) binder_dec_node_tmpref(target_node); /* * write barrier to synchronize with initialization * of log entry */ smp_wmb(); WRITE_ONCE(e->debug_id_done, t_debug_id); return; err_dead_proc_or_thread: return_error = BR_DEAD_REPLY; return_error_line = __LINE__; binder_dequeue_work(proc, tcomplete); err_translate_failed: err_bad_object_type: err_bad_offset: err_bad_parent: err_copy_data_failed: binder_free_txn_fixups(t); trace_binder_transaction_failed_buffer_release(t->buffer); binder_transaction_buffer_release(target_proc, t->buffer, offp); if (target_node) binder_dec_node_tmpref(target_node); target_node = NULL; t->buffer->transaction = NULL; binder_alloc_free_buf(&target_proc->alloc, t->buffer); err_binder_alloc_buf_failed: kfree(tcomplete); binder_stats_deleted(BINDER_STAT_TRANSACTION_COMPLETE); err_alloc_tcomplete_failed: kfree(t); binder_stats_deleted(BINDER_STAT_TRANSACTION); err_alloc_t_failed: err_bad_todo_list: err_bad_call_stack: err_empty_call_stack: err_dead_binder: err_invalid_target_handle: if (target_thread) binder_thread_dec_tmpref(target_thread); if (target_proc) binder_proc_dec_tmpref(target_proc); if (target_node) { binder_dec_node(target_node, 1, 0); binder_dec_node_tmpref(target_node); } binder_debug(BINDER_DEBUG_FAILED_TRANSACTION, "%d:%d transaction failed %d/%d, size %lld-%lld line %d\n", proc->pid, thread->pid, return_error, return_error_param, (u64)tr->data_size, (u64)tr->offsets_size, return_error_line); { struct binder_transaction_log_entry *fe; e->return_error = return_error; e->return_error_param = return_error_param; e->return_error_line = return_error_line; fe = binder_transaction_log_add(&binder_transaction_log_failed); *fe = *e; /* * write barrier to synchronize with initialization * of log entry */ smp_wmb(); WRITE_ONCE(e->debug_id_done, t_debug_id); WRITE_ONCE(fe->debug_id_done, t_debug_id); } BUG_ON(thread->return_error.cmd != BR_OK); if (in_reply_to) { thread->return_error.cmd = BR_TRANSACTION_COMPLETE; binder_enqueue_thread_work(thread, &thread->return_error.work); binder_send_failed_reply(in_reply_to, return_error); } else { thread->return_error.cmd = return_error; binder_enqueue_thread_work(thread, &thread->return_error.work); } } /** * binder_free_buf() - free the specified buffer * @proc: binder proc that owns buffer * @buffer: buffer to be freed * * If buffer for an async transaction, enqueue the next async * transaction from the node. * * Cleanup buffer and free it. */ static void binder_free_buf(struct binder_proc *proc, struct binder_buffer *buffer) { if (buffer->transaction) { buffer->transaction->buffer = NULL; buffer->transaction = NULL; } if (buffer->async_transaction && buffer->target_node) { struct binder_node *buf_node; struct binder_work *w; buf_node = buffer->target_node; binder_node_inner_lock(buf_node); BUG_ON(!buf_node->has_async_transaction); BUG_ON(buf_node->proc != proc); w = binder_dequeue_work_head_ilocked( &buf_node->async_todo); if (!w) { buf_node->has_async_transaction = false; } else { binder_enqueue_work_ilocked( w, &proc->todo); binder_wakeup_proc_ilocked(proc); } binder_node_inner_unlock(buf_node); } trace_binder_transaction_buffer_release(buffer); binder_transaction_buffer_release(proc, buffer, NULL); binder_alloc_free_buf(&proc->alloc, buffer); } static int binder_thread_write(struct binder_proc *proc, struct binder_thread *thread, binder_uintptr_t binder_buffer, size_t size, binder_size_t *consumed) { uint32_t cmd; struct binder_context *context = proc->context; void __user *buffer = (void __user *)(uintptr_t)binder_buffer; void __user *ptr = buffer + *consumed; void __user *end = buffer + size; while (ptr < end && thread->return_error.cmd == BR_OK) { int ret; if (get_user(cmd, (uint32_t __user *)ptr)) return -EFAULT; ptr += sizeof(uint32_t); trace_binder_command(cmd); if (_IOC_NR(cmd) < ARRAY_SIZE(binder_stats.bc)) { atomic_inc(&binder_stats.bc[_IOC_NR(cmd)]); atomic_inc(&proc->stats.bc[_IOC_NR(cmd)]); atomic_inc(&thread->stats.bc[_IOC_NR(cmd)]); } switch (cmd) { case BC_INCREFS: case BC_ACQUIRE: case BC_RELEASE: case BC_DECREFS: { uint32_t target; const char *debug_string; bool strong = cmd == BC_ACQUIRE || cmd == BC_RELEASE; bool increment = cmd == BC_INCREFS || cmd == BC_ACQUIRE; struct binder_ref_data rdata; if (get_user(target, (uint32_t __user *)ptr)) return -EFAULT; ptr += sizeof(uint32_t); ret = -1; if (increment && !target) { struct binder_node *ctx_mgr_node; mutex_lock(&context->context_mgr_node_lock); ctx_mgr_node = context->binder_context_mgr_node; if (ctx_mgr_node) ret = binder_inc_ref_for_node( proc, ctx_mgr_node, strong, NULL, &rdata); mutex_unlock(&context->context_mgr_node_lock); } if (ret) ret = binder_update_ref_for_handle( proc, target, increment, strong, &rdata); if (!ret && rdata.desc != target) { binder_user_error("%d:%d tried to acquire reference to desc %d, got %d instead\n", proc->pid, thread->pid, target, rdata.desc); } switch (cmd) { case BC_INCREFS: debug_string = "IncRefs"; break; case BC_ACQUIRE: debug_string = "Acquire"; break; case BC_RELEASE: debug_string = "Release"; break; case BC_DECREFS: default: debug_string = "DecRefs"; break; } if (ret) { binder_user_error("%d:%d %s %d refcount change on invalid ref %d ret %d\n", proc->pid, thread->pid, debug_string, strong, target, ret); break; } binder_debug(BINDER_DEBUG_USER_REFS, "%d:%d %s ref %d desc %d s %d w %d\n", proc->pid, thread->pid, debug_string, rdata.debug_id, rdata.desc, rdata.strong, rdata.weak); break; } case BC_INCREFS_DONE: case BC_ACQUIRE_DONE: { binder_uintptr_t node_ptr; binder_uintptr_t cookie; struct binder_node *node; bool free_node; if (get_user(node_ptr, (binder_uintptr_t __user *)ptr)) return -EFAULT; ptr += sizeof(binder_uintptr_t); if (get_user(cookie, (binder_uintptr_t __user *)ptr)) return -EFAULT; ptr += sizeof(binder_uintptr_t); node = binder_get_node(proc, node_ptr); if (node == NULL) { binder_user_error("%d:%d %s u%016llx no match\n", proc->pid, thread->pid, cmd == BC_INCREFS_DONE ? "BC_INCREFS_DONE" : "BC_ACQUIRE_DONE", (u64)node_ptr); break; } if (cookie != node->cookie) { binder_user_error("%d:%d %s u%016llx node %d cookie mismatch %016llx != %016llx\n", proc->pid, thread->pid, cmd == BC_INCREFS_DONE ? "BC_INCREFS_DONE" : "BC_ACQUIRE_DONE", (u64)node_ptr, node->debug_id, (u64)cookie, (u64)node->cookie); binder_put_node(node); break; } binder_node_inner_lock(node); if (cmd == BC_ACQUIRE_DONE) { if (node->pending_strong_ref == 0) { binder_user_error("%d:%d BC_ACQUIRE_DONE node %d has no pending acquire request\n", proc->pid, thread->pid, node->debug_id); binder_node_inner_unlock(node); binder_put_node(node); break; } node->pending_strong_ref = 0; } else { if (node->pending_weak_ref == 0) { binder_user_error("%d:%d BC_INCREFS_DONE node %d has no pending increfs request\n", proc->pid, thread->pid, node->debug_id); binder_node_inner_unlock(node); binder_put_node(node); break; } node->pending_weak_ref = 0; } free_node = binder_dec_node_nilocked(node, cmd == BC_ACQUIRE_DONE, 0); WARN_ON(free_node); binder_debug(BINDER_DEBUG_USER_REFS, "%d:%d %s node %d ls %d lw %d tr %d\n", proc->pid, thread->pid, cmd == BC_INCREFS_DONE ? "BC_INCREFS_DONE" : "BC_ACQUIRE_DONE", node->debug_id, node->local_strong_refs, node->local_weak_refs, node->tmp_refs); binder_node_inner_unlock(node); binder_put_node(node); break; } case BC_ATTEMPT_ACQUIRE: pr_err("BC_ATTEMPT_ACQUIRE not supported\n"); return -EINVAL; case BC_ACQUIRE_RESULT: pr_err("BC_ACQUIRE_RESULT not supported\n"); return -EINVAL; case BC_FREE_BUFFER: { binder_uintptr_t data_ptr; struct binder_buffer *buffer; if (get_user(data_ptr, (binder_uintptr_t __user *)ptr)) return -EFAULT; ptr += sizeof(binder_uintptr_t); buffer = binder_alloc_prepare_to_free(&proc->alloc, data_ptr); if (IS_ERR_OR_NULL(buffer)) { if (PTR_ERR(buffer) == -EPERM) { binder_user_error( "%d:%d BC_FREE_BUFFER u%016llx matched unreturned or currently freeing buffer\n", proc->pid, thread->pid, (u64)data_ptr); } else { binder_user_error( "%d:%d BC_FREE_BUFFER u%016llx no match\n", proc->pid, thread->pid, (u64)data_ptr); } break; } binder_debug(BINDER_DEBUG_FREE_BUFFER, "%d:%d BC_FREE_BUFFER u%016llx found buffer %d for %s transaction\n", proc->pid, thread->pid, (u64)data_ptr, buffer->debug_id, buffer->transaction ? "active" : "finished"); binder_free_buf(proc, buffer); break; } case BC_TRANSACTION_SG: case BC_REPLY_SG: { struct binder_transaction_data_sg tr; if (copy_from_user(&tr, ptr, sizeof(tr))) return -EFAULT; ptr += sizeof(tr); binder_transaction(proc, thread, &tr.transaction_data, cmd == BC_REPLY_SG, tr.buffers_size); break; } case BC_TRANSACTION: case BC_REPLY: { struct binder_transaction_data tr; if (copy_from_user(&tr, ptr, sizeof(tr))) return -EFAULT; ptr += sizeof(tr); binder_transaction(proc, thread, &tr, cmd == BC_REPLY, 0); break; } case BC_REGISTER_LOOPER: binder_debug(BINDER_DEBUG_THREADS, "%d:%d BC_REGISTER_LOOPER\n", proc->pid, thread->pid); binder_inner_proc_lock(proc); if (thread->looper & BINDER_LOOPER_STATE_ENTERED) { thread->looper |= BINDER_LOOPER_STATE_INVALID; binder_user_error("%d:%d ERROR: BC_REGISTER_LOOPER called after BC_ENTER_LOOPER\n", proc->pid, thread->pid); } else if (proc->requested_threads == 0) { thread->looper |= BINDER_LOOPER_STATE_INVALID; binder_user_error("%d:%d ERROR: BC_REGISTER_LOOPER called without request\n", proc->pid, thread->pid); } else { proc->requested_threads--; proc->requested_threads_started++; } thread->looper |= BINDER_LOOPER_STATE_REGISTERED; binder_inner_proc_unlock(proc); break; case BC_ENTER_LOOPER: binder_debug(BINDER_DEBUG_THREADS, "%d:%d BC_ENTER_LOOPER\n", proc->pid, thread->pid); if (thread->looper & BINDER_LOOPER_STATE_REGISTERED) { thread->looper |= BINDER_LOOPER_STATE_INVALID; binder_user_error("%d:%d ERROR: BC_ENTER_LOOPER called after BC_REGISTER_LOOPER\n", proc->pid, thread->pid); } thread->looper |= BINDER_LOOPER_STATE_ENTERED; break; case BC_EXIT_LOOPER: binder_debug(BINDER_DEBUG_THREADS, "%d:%d BC_EXIT_LOOPER\n", proc->pid, thread->pid); thread->looper |= BINDER_LOOPER_STATE_EXITED; break; case BC_REQUEST_DEATH_NOTIFICATION: case BC_CLEAR_DEATH_NOTIFICATION: { uint32_t target; binder_uintptr_t cookie; struct binder_ref *ref; struct binder_ref_death *death = NULL; if (get_user(target, (uint32_t __user *)ptr)) return -EFAULT; ptr += sizeof(uint32_t); if (get_user(cookie, (binder_uintptr_t __user *)ptr)) return -EFAULT; ptr += sizeof(binder_uintptr_t); if (cmd == BC_REQUEST_DEATH_NOTIFICATION) { /* * Allocate memory for death notification * before taking lock */ death = kzalloc(sizeof(*death), GFP_KERNEL); if (death == NULL) { WARN_ON(thread->return_error.cmd != BR_OK); thread->return_error.cmd = BR_ERROR; binder_enqueue_thread_work( thread, &thread->return_error.work); binder_debug( BINDER_DEBUG_FAILED_TRANSACTION, "%d:%d BC_REQUEST_DEATH_NOTIFICATION failed\n", proc->pid, thread->pid); break; } } binder_proc_lock(proc); ref = binder_get_ref_olocked(proc, target, false); if (ref == NULL) { binder_user_error("%d:%d %s invalid ref %d\n", proc->pid, thread->pid, cmd == BC_REQUEST_DEATH_NOTIFICATION ? "BC_REQUEST_DEATH_NOTIFICATION" : "BC_CLEAR_DEATH_NOTIFICATION", target); binder_proc_unlock(proc); kfree(death); break; } binder_debug(BINDER_DEBUG_DEATH_NOTIFICATION, "%d:%d %s %016llx ref %d desc %d s %d w %d for node %d\n", proc->pid, thread->pid, cmd == BC_REQUEST_DEATH_NOTIFICATION ? "BC_REQUEST_DEATH_NOTIFICATION" : "BC_CLEAR_DEATH_NOTIFICATION", (u64)cookie, ref->data.debug_id, ref->data.desc, ref->data.strong, ref->data.weak, ref->node->debug_id); binder_node_lock(ref->node); if (cmd == BC_REQUEST_DEATH_NOTIFICATION) { if (ref->death) { binder_user_error("%d:%d BC_REQUEST_DEATH_NOTIFICATION death notification already set\n", proc->pid, thread->pid); binder_node_unlock(ref->node); binder_proc_unlock(proc); kfree(death); break; } binder_stats_created(BINDER_STAT_DEATH); INIT_LIST_HEAD(&death->work.entry); death->cookie = cookie; ref->death = death; if (ref->node->proc == NULL) { ref->death->work.type = BINDER_WORK_DEAD_BINDER; binder_inner_proc_lock(proc); binder_enqueue_work_ilocked( &ref->death->work, &proc->todo); binder_wakeup_proc_ilocked(proc); binder_inner_proc_unlock(proc); } } else { if (ref->death == NULL) { binder_user_error("%d:%d BC_CLEAR_DEATH_NOTIFICATION death notification not active\n", proc->pid, thread->pid); binder_node_unlock(ref->node); binder_proc_unlock(proc); break; } death = ref->death; if (death->cookie != cookie) { binder_user_error("%d:%d BC_CLEAR_DEATH_NOTIFICATION death notification cookie mismatch %016llx != %016llx\n", proc->pid, thread->pid, (u64)death->cookie, (u64)cookie); binder_node_unlock(ref->node); binder_proc_unlock(proc); break; } ref->death = NULL; binder_inner_proc_lock(proc); if (list_empty(&death->work.entry)) { death->work.type = BINDER_WORK_CLEAR_DEATH_NOTIFICATION; if (thread->looper & (BINDER_LOOPER_STATE_REGISTERED | BINDER_LOOPER_STATE_ENTERED)) binder_enqueue_thread_work_ilocked( thread, &death->work); else { binder_enqueue_work_ilocked( &death->work, &proc->todo); binder_wakeup_proc_ilocked( proc); } } else { BUG_ON(death->work.type != BINDER_WORK_DEAD_BINDER); death->work.type = BINDER_WORK_DEAD_BINDER_AND_CLEAR; } binder_inner_proc_unlock(proc); } binder_node_unlock(ref->node); binder_proc_unlock(proc); } break; case BC_DEAD_BINDER_DONE: { struct binder_work *w; binder_uintptr_t cookie; struct binder_ref_death *death = NULL; if (get_user(cookie, (binder_uintptr_t __user *)ptr)) return -EFAULT; ptr += sizeof(cookie); binder_inner_proc_lock(proc); list_for_each_entry(w, &proc->delivered_death, entry) { struct binder_ref_death *tmp_death = container_of(w, struct binder_ref_death, work); if (tmp_death->cookie == cookie) { death = tmp_death; break; } } binder_debug(BINDER_DEBUG_DEAD_BINDER, "%d:%d BC_DEAD_BINDER_DONE %016llx found %pK\n", proc->pid, thread->pid, (u64)cookie, death); if (death == NULL) { binder_user_error("%d:%d BC_DEAD_BINDER_DONE %016llx not found\n", proc->pid, thread->pid, (u64)cookie); binder_inner_proc_unlock(proc); break; } binder_dequeue_work_ilocked(&death->work); if (death->work.type == BINDER_WORK_DEAD_BINDER_AND_CLEAR) { death->work.type = BINDER_WORK_CLEAR_DEATH_NOTIFICATION; if (thread->looper & (BINDER_LOOPER_STATE_REGISTERED | BINDER_LOOPER_STATE_ENTERED)) binder_enqueue_thread_work_ilocked( thread, &death->work); else { binder_enqueue_work_ilocked( &death->work, &proc->todo); binder_wakeup_proc_ilocked(proc); } } binder_inner_proc_unlock(proc); } break; default: pr_err("%d:%d unknown command %d\n", proc->pid, thread->pid, cmd); return -EINVAL; } *consumed = ptr - buffer; } return 0; } static void binder_stat_br(struct binder_proc *proc, struct binder_thread *thread, uint32_t cmd) { trace_binder_return(cmd); if (_IOC_NR(cmd) < ARRAY_SIZE(binder_stats.br)) { atomic_inc(&binder_stats.br[_IOC_NR(cmd)]); atomic_inc(&proc->stats.br[_IOC_NR(cmd)]); atomic_inc(&thread->stats.br[_IOC_NR(cmd)]); } } static int binder_put_node_cmd(struct binder_proc *proc, struct binder_thread *thread, void __user **ptrp, binder_uintptr_t node_ptr, binder_uintptr_t node_cookie, int node_debug_id, uint32_t cmd, const char *cmd_name) { void __user *ptr = *ptrp; if (put_user(cmd, (uint32_t __user *)ptr)) return -EFAULT; ptr += sizeof(uint32_t); if (put_user(node_ptr, (binder_uintptr_t __user *)ptr)) return -EFAULT; ptr += sizeof(binder_uintptr_t); if (put_user(node_cookie, (binder_uintptr_t __user *)ptr)) return -EFAULT; ptr += sizeof(binder_uintptr_t); binder_stat_br(proc, thread, cmd); binder_debug(BINDER_DEBUG_USER_REFS, "%d:%d %s %d u%016llx c%016llx\n", proc->pid, thread->pid, cmd_name, node_debug_id, (u64)node_ptr, (u64)node_cookie); *ptrp = ptr; return 0; } static int binder_wait_for_work(struct binder_thread *thread, bool do_proc_work) { DEFINE_WAIT(wait); struct binder_proc *proc = thread->proc; int ret = 0; freezer_do_not_count(); binder_inner_proc_lock(proc); for (;;) { prepare_to_wait(&thread->wait, &wait, TASK_INTERRUPTIBLE); if (binder_has_work_ilocked(thread, do_proc_work)) break; if (do_proc_work) list_add(&thread->waiting_thread_node, &proc->waiting_threads); binder_inner_proc_unlock(proc); schedule(); binder_inner_proc_lock(proc); list_del_init(&thread->waiting_thread_node); if (signal_pending(current)) { ret = -ERESTARTSYS; break; } } finish_wait(&thread->wait, &wait); binder_inner_proc_unlock(proc); freezer_count(); return ret; } /** * binder_apply_fd_fixups() - finish fd translation * @t: binder transaction with list of fd fixups * * Now that we are in the context of the transaction target * process, we can allocate and install fds. Process the * list of fds to translate and fixup the buffer with the * new fds. * * If we fail to allocate an fd, then free the resources by * fput'ing files that have not been processed and ksys_close'ing * any fds that have already been allocated. */ static int binder_apply_fd_fixups(struct binder_transaction *t) { struct binder_txn_fd_fixup *fixup, *tmp; int ret = 0; list_for_each_entry(fixup, &t->fd_fixups, fixup_entry) { int fd = get_unused_fd_flags(O_CLOEXEC); u32 *fdp; if (fd < 0) { binder_debug(BINDER_DEBUG_TRANSACTION, "failed fd fixup txn %d fd %d\n", t->debug_id, fd); ret = -ENOMEM; break; } binder_debug(BINDER_DEBUG_TRANSACTION, "fd fixup txn %d fd %d\n", t->debug_id, fd); trace_binder_transaction_fd_recv(t, fd, fixup->offset); fd_install(fd, fixup->file); fixup->file = NULL; fdp = (u32 *)(t->buffer->data + fixup->offset); /* * This store can cause problems for CPUs with a * VIVT cache (eg ARMv5) since the cache cannot * detect virtual aliases to the same physical cacheline. * To support VIVT, this address and the user-space VA * would both need to be flushed. Since this kernel * VA is not constructed via page_to_virt(), we can't * use flush_dcache_page() on it, so we'd have to use * an internal function. If devices with VIVT ever * need to run Android, we'll either need to go back * to patching the translated fd from the sender side * (using the non-standard kernel functions), or rework * how the kernel uses the buffer to use page_to_virt() * addresses instead of allocating in our own vm area. * * For now, we disable compilation if CONFIG_CPU_CACHE_VIVT. */ *fdp = fd; } list_for_each_entry_safe(fixup, tmp, &t->fd_fixups, fixup_entry) { if (fixup->file) { fput(fixup->file); } else if (ret) { u32 *fdp = (u32 *)(t->buffer->data + fixup->offset); ksys_close(*fdp); } list_del(&fixup->fixup_entry); kfree(fixup); } return ret; } static int binder_thread_read(struct binder_proc *proc, struct binder_thread *thread, binder_uintptr_t binder_buffer, size_t size, binder_size_t *consumed, int non_block) { void __user *buffer = (void __user *)(uintptr_t)binder_buffer; void __user *ptr = buffer + *consumed; void __user *end = buffer + size; int ret = 0; int wait_for_proc_work; if (*consumed == 0) { if (put_user(BR_NOOP, (uint32_t __user *)ptr)) return -EFAULT; ptr += sizeof(uint32_t); } retry: binder_inner_proc_lock(proc); wait_for_proc_work = binder_available_for_proc_work_ilocked(thread); binder_inner_proc_unlock(proc); thread->looper |= BINDER_LOOPER_STATE_WAITING; trace_binder_wait_for_work(wait_for_proc_work, !!thread->transaction_stack, !binder_worklist_empty(proc, &thread->todo)); if (wait_for_proc_work) { if (!(thread->looper & (BINDER_LOOPER_STATE_REGISTERED | BINDER_LOOPER_STATE_ENTERED))) { binder_user_error("%d:%d ERROR: Thread waiting for process work before calling BC_REGISTER_LOOPER or BC_ENTER_LOOPER (state %x)\n", proc->pid, thread->pid, thread->looper); wait_event_interruptible(binder_user_error_wait, binder_stop_on_user_error < 2); } binder_set_nice(proc->default_priority); } if (non_block) { if (!binder_has_work(thread, wait_for_proc_work)) ret = -EAGAIN; } else { ret = binder_wait_for_work(thread, wait_for_proc_work); } thread->looper &= ~BINDER_LOOPER_STATE_WAITING; if (ret) return ret; while (1) { uint32_t cmd; struct binder_transaction_data tr; struct binder_work *w = NULL; struct list_head *list = NULL; struct binder_transaction *t = NULL; struct binder_thread *t_from; binder_inner_proc_lock(proc); if (!binder_worklist_empty_ilocked(&thread->todo)) list = &thread->todo; else if (!binder_worklist_empty_ilocked(&proc->todo) && wait_for_proc_work) list = &proc->todo; else { binder_inner_proc_unlock(proc); /* no data added */ if (ptr - buffer == 4 && !thread->looper_need_return) goto retry; break; } if (end - ptr < sizeof(tr) + 4) { binder_inner_proc_unlock(proc); break; } w = binder_dequeue_work_head_ilocked(list); if (binder_worklist_empty_ilocked(&thread->todo)) thread->process_todo = false; switch (w->type) { case BINDER_WORK_TRANSACTION: { binder_inner_proc_unlock(proc); t = container_of(w, struct binder_transaction, work); } break; case BINDER_WORK_RETURN_ERROR: { struct binder_error *e = container_of( w, struct binder_error, work); WARN_ON(e->cmd == BR_OK); binder_inner_proc_unlock(proc); if (put_user(e->cmd, (uint32_t __user *)ptr)) return -EFAULT; cmd = e->cmd; e->cmd = BR_OK; ptr += sizeof(uint32_t); binder_stat_br(proc, thread, cmd); } break; case BINDER_WORK_TRANSACTION_COMPLETE: { binder_inner_proc_unlock(proc); cmd = BR_TRANSACTION_COMPLETE; if (put_user(cmd, (uint32_t __user *)ptr)) return -EFAULT; ptr += sizeof(uint32_t); binder_stat_br(proc, thread, cmd); binder_debug(BINDER_DEBUG_TRANSACTION_COMPLETE, "%d:%d BR_TRANSACTION_COMPLETE\n", proc->pid, thread->pid); kfree(w); binder_stats_deleted(BINDER_STAT_TRANSACTION_COMPLETE); } break; case BINDER_WORK_NODE: { struct binder_node *node = container_of(w, struct binder_node, work); int strong, weak; binder_uintptr_t node_ptr = node->ptr; binder_uintptr_t node_cookie = node->cookie; int node_debug_id = node->debug_id; int has_weak_ref; int has_strong_ref; void __user *orig_ptr = ptr; BUG_ON(proc != node->proc); strong = node->internal_strong_refs || node->local_strong_refs; weak = !hlist_empty(&node->refs) || node->local_weak_refs || node->tmp_refs || strong; has_strong_ref = node->has_strong_ref; has_weak_ref = node->has_weak_ref; if (weak && !has_weak_ref) { node->has_weak_ref = 1; node->pending_weak_ref = 1; node->local_weak_refs++; } if (strong && !has_strong_ref) { node->has_strong_ref = 1; node->pending_strong_ref = 1; node->local_strong_refs++; } if (!strong && has_strong_ref) node->has_strong_ref = 0; if (!weak && has_weak_ref) node->has_weak_ref = 0; if (!weak && !strong) { binder_debug(BINDER_DEBUG_INTERNAL_REFS, "%d:%d node %d u%016llx c%016llx deleted\n", proc->pid, thread->pid, node_debug_id, (u64)node_ptr, (u64)node_cookie); rb_erase(&node->rb_node, &proc->nodes); binder_inner_proc_unlock(proc); binder_node_lock(node); /* * Acquire the node lock before freeing the * node to serialize with other threads that * may have been holding the node lock while * decrementing this node (avoids race where * this thread frees while the other thread * is unlocking the node after the final * decrement) */ binder_node_unlock(node); binder_free_node(node); } else binder_inner_proc_unlock(proc); if (weak && !has_weak_ref) ret = binder_put_node_cmd( proc, thread, &ptr, node_ptr, node_cookie, node_debug_id, BR_INCREFS, "BR_INCREFS"); if (!ret && strong && !has_strong_ref) ret = binder_put_node_cmd( proc, thread, &ptr, node_ptr, node_cookie, node_debug_id, BR_ACQUIRE, "BR_ACQUIRE"); if (!ret && !strong && has_strong_ref) ret = binder_put_node_cmd( proc, thread, &ptr, node_ptr, node_cookie, node_debug_id, BR_RELEASE, "BR_RELEASE"); if (!ret && !weak && has_weak_ref) ret = binder_put_node_cmd( proc, thread, &ptr, node_ptr, node_cookie, node_debug_id, BR_DECREFS, "BR_DECREFS"); if (orig_ptr == ptr) binder_debug(BINDER_DEBUG_INTERNAL_REFS, "%d:%d node %d u%016llx c%016llx state unchanged\n", proc->pid, thread->pid, node_debug_id, (u64)node_ptr, (u64)node_cookie); if (ret) return ret; } break; case BINDER_WORK_DEAD_BINDER: case BINDER_WORK_DEAD_BINDER_AND_CLEAR: case BINDER_WORK_CLEAR_DEATH_NOTIFICATION: { struct binder_ref_death *death; uint32_t cmd; binder_uintptr_t cookie; death = container_of(w, struct binder_ref_death, work); if (w->type == BINDER_WORK_CLEAR_DEATH_NOTIFICATION) cmd = BR_CLEAR_DEATH_NOTIFICATION_DONE; else cmd = BR_DEAD_BINDER; cookie = death->cookie; binder_debug(BINDER_DEBUG_DEATH_NOTIFICATION, "%d:%d %s %016llx\n", proc->pid, thread->pid, cmd == BR_DEAD_BINDER ? "BR_DEAD_BINDER" : "BR_CLEAR_DEATH_NOTIFICATION_DONE", (u64)cookie); if (w->type == BINDER_WORK_CLEAR_DEATH_NOTIFICATION) { binder_inner_proc_unlock(proc); kfree(death); binder_stats_deleted(BINDER_STAT_DEATH); } else { binder_enqueue_work_ilocked( w, &proc->delivered_death); binder_inner_proc_unlock(proc); } if (put_user(cmd, (uint32_t __user *)ptr)) return -EFAULT; ptr += sizeof(uint32_t); if (put_user(cookie, (binder_uintptr_t __user *)ptr)) return -EFAULT; ptr += sizeof(binder_uintptr_t); binder_stat_br(proc, thread, cmd); if (cmd == BR_DEAD_BINDER) goto done; /* DEAD_BINDER notifications can cause transactions */ } break; default: binder_inner_proc_unlock(proc); pr_err("%d:%d: bad work type %d\n", proc->pid, thread->pid, w->type); break; } if (!t) continue; BUG_ON(t->buffer == NULL); if (t->buffer->target_node) { struct binder_node *target_node = t->buffer->target_node; tr.target.ptr = target_node->ptr; tr.cookie = target_node->cookie; t->saved_priority = task_nice(current); if (t->priority < target_node->min_priority && !(t->flags & TF_ONE_WAY)) binder_set_nice(t->priority); else if (!(t->flags & TF_ONE_WAY) || t->saved_priority > target_node->min_priority) binder_set_nice(target_node->min_priority); cmd = BR_TRANSACTION; } else { tr.target.ptr = 0; tr.cookie = 0; cmd = BR_REPLY; } tr.code = t->code; tr.flags = t->flags; tr.sender_euid = from_kuid(current_user_ns(), t->sender_euid); t_from = binder_get_txn_from(t); if (t_from) { struct task_struct *sender = t_from->proc->tsk; tr.sender_pid = task_tgid_nr_ns(sender, task_active_pid_ns(current)); } else { tr.sender_pid = 0; } ret = binder_apply_fd_fixups(t); if (ret) { struct binder_buffer *buffer = t->buffer; bool oneway = !!(t->flags & TF_ONE_WAY); int tid = t->debug_id; if (t_from) binder_thread_dec_tmpref(t_from); buffer->transaction = NULL; binder_cleanup_transaction(t, "fd fixups failed", BR_FAILED_REPLY); binder_free_buf(proc, buffer); binder_debug(BINDER_DEBUG_FAILED_TRANSACTION, "%d:%d %stransaction %d fd fixups failed %d/%d, line %d\n", proc->pid, thread->pid, oneway ? "async " : (cmd == BR_REPLY ? "reply " : ""), tid, BR_FAILED_REPLY, ret, __LINE__); if (cmd == BR_REPLY) { cmd = BR_FAILED_REPLY; if (put_user(cmd, (uint32_t __user *)ptr)) return -EFAULT; ptr += sizeof(uint32_t); binder_stat_br(proc, thread, cmd); break; } continue; } tr.data_size = t->buffer->data_size; tr.offsets_size = t->buffer->offsets_size; tr.data.ptr.buffer = (binder_uintptr_t) ((uintptr_t)t->buffer->data + binder_alloc_get_user_buffer_offset(&proc->alloc)); tr.data.ptr.offsets = tr.data.ptr.buffer + ALIGN(t->buffer->data_size, sizeof(void *)); if (put_user(cmd, (uint32_t __user *)ptr)) { if (t_from) binder_thread_dec_tmpref(t_from); binder_cleanup_transaction(t, "put_user failed", BR_FAILED_REPLY); return -EFAULT; } ptr += sizeof(uint32_t); if (copy_to_user(ptr, &tr, sizeof(tr))) { if (t_from) binder_thread_dec_tmpref(t_from); binder_cleanup_transaction(t, "copy_to_user failed", BR_FAILED_REPLY); return -EFAULT; } ptr += sizeof(tr); trace_binder_transaction_received(t); binder_stat_br(proc, thread, cmd); binder_debug(BINDER_DEBUG_TRANSACTION, "%d:%d %s %d %d:%d, cmd %d size %zd-%zd ptr %016llx-%016llx\n", proc->pid, thread->pid, (cmd == BR_TRANSACTION) ? "BR_TRANSACTION" : "BR_REPLY", t->debug_id, t_from ? t_from->proc->pid : 0, t_from ? t_from->pid : 0, cmd, t->buffer->data_size, t->buffer->offsets_size, (u64)tr.data.ptr.buffer, (u64)tr.data.ptr.offsets); if (t_from) binder_thread_dec_tmpref(t_from); t->buffer->allow_user_free = 1; if (cmd == BR_TRANSACTION && !(t->flags & TF_ONE_WAY)) { binder_inner_proc_lock(thread->proc); t->to_parent = thread->transaction_stack; t->to_thread = thread; thread->transaction_stack = t; binder_inner_proc_unlock(thread->proc); } else { binder_free_transaction(t); } break; } done: *consumed = ptr - buffer; binder_inner_proc_lock(proc); if (proc->requested_threads == 0 && list_empty(&thread->proc->waiting_threads) && proc->requested_threads_started < proc->max_threads && (thread->looper & (BINDER_LOOPER_STATE_REGISTERED | BINDER_LOOPER_STATE_ENTERED)) /* the user-space code fails to */ /*spawn a new thread if we leave this out */) { proc->requested_threads++; binder_inner_proc_unlock(proc); binder_debug(BINDER_DEBUG_THREADS, "%d:%d BR_SPAWN_LOOPER\n", proc->pid, thread->pid); if (put_user(BR_SPAWN_LOOPER, (uint32_t __user *)buffer)) return -EFAULT; binder_stat_br(proc, thread, BR_SPAWN_LOOPER); } else binder_inner_proc_unlock(proc); return 0; } static void binder_release_work(struct binder_proc *proc, struct list_head *list) { struct binder_work *w; while (1) { w = binder_dequeue_work_head(proc, list); if (!w) return; switch (w->type) { case BINDER_WORK_TRANSACTION: { struct binder_transaction *t; t = container_of(w, struct binder_transaction, work); binder_cleanup_transaction(t, "process died.", BR_DEAD_REPLY); } break; case BINDER_WORK_RETURN_ERROR: { struct binder_error *e = container_of( w, struct binder_error, work); binder_debug(BINDER_DEBUG_DEAD_TRANSACTION, "undelivered TRANSACTION_ERROR: %u\n", e->cmd); } break; case BINDER_WORK_TRANSACTION_COMPLETE: { binder_debug(BINDER_DEBUG_DEAD_TRANSACTION, "undelivered TRANSACTION_COMPLETE\n"); kfree(w); binder_stats_deleted(BINDER_STAT_TRANSACTION_COMPLETE); } break; case BINDER_WORK_DEAD_BINDER_AND_CLEAR: case BINDER_WORK_CLEAR_DEATH_NOTIFICATION: { struct binder_ref_death *death; death = container_of(w, struct binder_ref_death, work); binder_debug(BINDER_DEBUG_DEAD_TRANSACTION, "undelivered death notification, %016llx\n", (u64)death->cookie); kfree(death); binder_stats_deleted(BINDER_STAT_DEATH); } break; default: pr_err("unexpected work type, %d, not freed\n", w->type); break; } } } static struct binder_thread *binder_get_thread_ilocked( struct binder_proc *proc, struct binder_thread *new_thread) { struct binder_thread *thread = NULL; struct rb_node *parent = NULL; struct rb_node **p = &proc->threads.rb_node; while (*p) { parent = *p; thread = rb_entry(parent, struct binder_thread, rb_node); if (current->pid < thread->pid) p = &(*p)->rb_left; else if (current->pid > thread->pid) p = &(*p)->rb_right; else return thread; } if (!new_thread) return NULL; thread = new_thread; binder_stats_created(BINDER_STAT_THREAD); thread->proc = proc; thread->pid = current->pid; atomic_set(&thread->tmp_ref, 0); init_waitqueue_head(&thread->wait); INIT_LIST_HEAD(&thread->todo); rb_link_node(&thread->rb_node, parent, p); rb_insert_color(&thread->rb_node, &proc->threads); thread->looper_need_return = true; thread->return_error.work.type = BINDER_WORK_RETURN_ERROR; thread->return_error.cmd = BR_OK; thread->reply_error.work.type = BINDER_WORK_RETURN_ERROR; thread->reply_error.cmd = BR_OK; INIT_LIST_HEAD(&new_thread->waiting_thread_node); return thread; } static struct binder_thread *binder_get_thread(struct binder_proc *proc) { struct binder_thread *thread; struct binder_thread *new_thread; binder_inner_proc_lock(proc); thread = binder_get_thread_ilocked(proc, NULL); binder_inner_proc_unlock(proc); if (!thread) { new_thread = kzalloc(sizeof(*thread), GFP_KERNEL); if (new_thread == NULL) return NULL; binder_inner_proc_lock(proc); thread = binder_get_thread_ilocked(proc, new_thread); binder_inner_proc_unlock(proc); if (thread != new_thread) kfree(new_thread); } return thread; } static void binder_free_proc(struct binder_proc *proc) { BUG_ON(!list_empty(&proc->todo)); BUG_ON(!list_empty(&proc->delivered_death)); binder_alloc_deferred_release(&proc->alloc); put_task_struct(proc->tsk); binder_stats_deleted(BINDER_STAT_PROC); kfree(proc); } static void binder_free_thread(struct binder_thread *thread) { BUG_ON(!list_empty(&thread->todo)); binder_stats_deleted(BINDER_STAT_THREAD); binder_proc_dec_tmpref(thread->proc); kfree(thread); } static int binder_thread_release(struct binder_proc *proc, struct binder_thread *thread) { struct binder_transaction *t; struct binder_transaction *send_reply = NULL; int active_transactions = 0; struct binder_transaction *last_t = NULL; binder_inner_proc_lock(thread->proc); /* * take a ref on the proc so it survives * after we remove this thread from proc->threads. * The corresponding dec is when we actually * free the thread in binder_free_thread() */ proc->tmp_ref++; /* * take a ref on this thread to ensure it * survives while we are releasing it */ atomic_inc(&thread->tmp_ref); rb_erase(&thread->rb_node, &proc->threads); t = thread->transaction_stack; if (t) { spin_lock(&t->lock); if (t->to_thread == thread) send_reply = t; } else { __acquire(&t->lock); } thread->is_dead = true; while (t) { last_t = t; active_transactions++; binder_debug(BINDER_DEBUG_DEAD_TRANSACTION, "release %d:%d transaction %d %s, still active\n", proc->pid, thread->pid, t->debug_id, (t->to_thread == thread) ? "in" : "out"); if (t->to_thread == thread) { t->to_proc = NULL; t->to_thread = NULL; if (t->buffer) { t->buffer->transaction = NULL; t->buffer = NULL; } t = t->to_parent; } else if (t->from == thread) { t->from = NULL; t = t->from_parent; } else BUG(); spin_unlock(&last_t->lock); if (t) spin_lock(&t->lock); else __acquire(&t->lock); } /* annotation for sparse, lock not acquired in last iteration above */ __release(&t->lock); /* * If this thread used poll, make sure we remove the waitqueue * from any epoll data structures holding it with POLLFREE. * waitqueue_active() is safe to use here because we're holding * the inner lock. */ if ((thread->looper & BINDER_LOOPER_STATE_POLL) && waitqueue_active(&thread->wait)) { wake_up_poll(&thread->wait, EPOLLHUP | POLLFREE); } binder_inner_proc_unlock(thread->proc); /* * This is needed to avoid races between wake_up_poll() above and * and ep_remove_waitqueue() called for other reasons (eg the epoll file * descriptor being closed); ep_remove_waitqueue() holds an RCU read * lock, so we can be sure it's done after calling synchronize_rcu(). */ if (thread->looper & BINDER_LOOPER_STATE_POLL) synchronize_rcu(); if (send_reply) binder_send_failed_reply(send_reply, BR_DEAD_REPLY); binder_release_work(proc, &thread->todo); binder_thread_dec_tmpref(thread); return active_transactions; } static __poll_t binder_poll(struct file *filp, struct poll_table_struct *wait) { struct binder_proc *proc = filp->private_data; struct binder_thread *thread = NULL; bool wait_for_proc_work; thread = binder_get_thread(proc); if (!thread) return POLLERR; binder_inner_proc_lock(thread->proc); thread->looper |= BINDER_LOOPER_STATE_POLL; wait_for_proc_work = binder_available_for_proc_work_ilocked(thread); binder_inner_proc_unlock(thread->proc); poll_wait(filp, &thread->wait, wait); if (binder_has_work(thread, wait_for_proc_work)) return EPOLLIN; return 0; } static int binder_ioctl_write_read(struct file *filp, unsigned int cmd, unsigned long arg, struct binder_thread *thread) { int ret = 0; struct binder_proc *proc = filp->private_data; unsigned int size = _IOC_SIZE(cmd); void __user *ubuf = (void __user *)arg; struct binder_write_read bwr; if (size != sizeof(struct binder_write_read)) { ret = -EINVAL; goto out; } if (copy_from_user(&bwr, ubuf, sizeof(bwr))) { ret = -EFAULT; goto out; } binder_debug(BINDER_DEBUG_READ_WRITE, "%d:%d write %lld at %016llx, read %lld at %016llx\n", proc->pid, thread->pid, (u64)bwr.write_size, (u64)bwr.write_buffer, (u64)bwr.read_size, (u64)bwr.read_buffer); if (bwr.write_size > 0) { ret = binder_thread_write(proc, thread, bwr.write_buffer, bwr.write_size, &bwr.write_consumed); trace_binder_write_done(ret); if (ret < 0) { bwr.read_consumed = 0; if (copy_to_user(ubuf, &bwr, sizeof(bwr))) ret = -EFAULT; goto out; } } if (bwr.read_size > 0) { ret = binder_thread_read(proc, thread, bwr.read_buffer, bwr.read_size, &bwr.read_consumed, filp->f_flags & O_NONBLOCK); trace_binder_read_done(ret); binder_inner_proc_lock(proc); if (!binder_worklist_empty_ilocked(&proc->todo)) binder_wakeup_proc_ilocked(proc); binder_inner_proc_unlock(proc); if (ret < 0) { if (copy_to_user(ubuf, &bwr, sizeof(bwr))) ret = -EFAULT; goto out; } } binder_debug(BINDER_DEBUG_READ_WRITE, "%d:%d wrote %lld of %lld, read return %lld of %lld\n", proc->pid, thread->pid, (u64)bwr.write_consumed, (u64)bwr.write_size, (u64)bwr.read_consumed, (u64)bwr.read_size); if (copy_to_user(ubuf, &bwr, sizeof(bwr))) { ret = -EFAULT; goto out; } out: return ret; } static int binder_ioctl_set_ctx_mgr(struct file *filp) { int ret = 0; struct binder_proc *proc = filp->private_data; struct binder_context *context = proc->context; struct binder_node *new_node; kuid_t curr_euid = current_euid(); mutex_lock(&context->context_mgr_node_lock); if (context->binder_context_mgr_node) { pr_err("BINDER_SET_CONTEXT_MGR already set\n"); ret = -EBUSY; goto out; } ret = security_binder_set_context_mgr(proc->tsk); if (ret < 0) goto out; if (uid_valid(context->binder_context_mgr_uid)) { if (!uid_eq(context->binder_context_mgr_uid, curr_euid)) { pr_err("BINDER_SET_CONTEXT_MGR bad uid %d != %d\n", from_kuid(&init_user_ns, curr_euid), from_kuid(&init_user_ns, context->binder_context_mgr_uid)); ret = -EPERM; goto out; } } else { context->binder_context_mgr_uid = curr_euid; } new_node = binder_new_node(proc, NULL); if (!new_node) { ret = -ENOMEM; goto out; } binder_node_lock(new_node); new_node->local_weak_refs++; new_node->local_strong_refs++; new_node->has_strong_ref = 1; new_node->has_weak_ref = 1; context->binder_context_mgr_node = new_node; binder_node_unlock(new_node); binder_put_node(new_node); out: mutex_unlock(&context->context_mgr_node_lock); return ret; } static int binder_ioctl_get_node_info_for_ref(struct binder_proc *proc, struct binder_node_info_for_ref *info) { struct binder_node *node; struct binder_context *context = proc->context; __u32 handle = info->handle; if (info->strong_count || info->weak_count || info->reserved1 || info->reserved2 || info->reserved3) { binder_user_error("%d BINDER_GET_NODE_INFO_FOR_REF: only handle may be non-zero.", proc->pid); return -EINVAL; } /* This ioctl may only be used by the context manager */ mutex_lock(&context->context_mgr_node_lock); if (!context->binder_context_mgr_node || context->binder_context_mgr_node->proc != proc) { mutex_unlock(&context->context_mgr_node_lock); return -EPERM; } mutex_unlock(&context->context_mgr_node_lock); node = binder_get_node_from_ref(proc, handle, true, NULL); if (!node) return -EINVAL; info->strong_count = node->local_strong_refs + node->internal_strong_refs; info->weak_count = node->local_weak_refs; binder_put_node(node); return 0; } static int binder_ioctl_get_node_debug_info(struct binder_proc *proc, struct binder_node_debug_info *info) { struct rb_node *n; binder_uintptr_t ptr = info->ptr; memset(info, 0, sizeof(*info)); binder_inner_proc_lock(proc); for (n = rb_first(&proc->nodes); n != NULL; n = rb_next(n)) { struct binder_node *node = rb_entry(n, struct binder_node, rb_node); if (node->ptr > ptr) { info->ptr = node->ptr; info->cookie = node->cookie; info->has_strong_ref = node->has_strong_ref; info->has_weak_ref = node->has_weak_ref; break; } } binder_inner_proc_unlock(proc); return 0; } static long binder_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) { int ret; struct binder_proc *proc = filp->private_data; struct binder_thread *thread; unsigned int size = _IOC_SIZE(cmd); void __user *ubuf = (void __user *)arg; /*pr_info("binder_ioctl: %d:%d %x %lx\n", proc->pid, current->pid, cmd, arg);*/ binder_selftest_alloc(&proc->alloc); trace_binder_ioctl(cmd, arg); ret = wait_event_interruptible(binder_user_error_wait, binder_stop_on_user_error < 2); if (ret) goto err_unlocked; thread = binder_get_thread(proc); if (thread == NULL) { ret = -ENOMEM; goto err; } switch (cmd) { case BINDER_WRITE_READ: ret = binder_ioctl_write_read(filp, cmd, arg, thread); if (ret) goto err; break; case BINDER_SET_MAX_THREADS: { int max_threads; if (copy_from_user(&max_threads, ubuf, sizeof(max_threads))) { ret = -EINVAL; goto err; } binder_inner_proc_lock(proc); proc->max_threads = max_threads; binder_inner_proc_unlock(proc); break; } case BINDER_SET_CONTEXT_MGR: ret = binder_ioctl_set_ctx_mgr(filp); if (ret) goto err; break; case BINDER_THREAD_EXIT: binder_debug(BINDER_DEBUG_THREADS, "%d:%d exit\n", proc->pid, thread->pid); binder_thread_release(proc, thread); thread = NULL; break; case BINDER_VERSION: { struct binder_version __user *ver = ubuf; if (size != sizeof(struct binder_version)) { ret = -EINVAL; goto err; } if (put_user(BINDER_CURRENT_PROTOCOL_VERSION, &ver->protocol_version)) { ret = -EINVAL; goto err; } break; } case BINDER_GET_NODE_INFO_FOR_REF: { struct binder_node_info_for_ref info; if (copy_from_user(&info, ubuf, sizeof(info))) { ret = -EFAULT; goto err; } ret = binder_ioctl_get_node_info_for_ref(proc, &info); if (ret < 0) goto err; if (copy_to_user(ubuf, &info, sizeof(info))) { ret = -EFAULT; goto err; } break; } case BINDER_GET_NODE_DEBUG_INFO: { struct binder_node_debug_info info; if (copy_from_user(&info, ubuf, sizeof(info))) { ret = -EFAULT; goto err; } ret = binder_ioctl_get_node_debug_info(proc, &info); if (ret < 0) goto err; if (copy_to_user(ubuf, &info, sizeof(info))) { ret = -EFAULT; goto err; } break; } default: ret = -EINVAL; goto err; } ret = 0; err: if (thread) thread->looper_need_return = false; wait_event_interruptible(binder_user_error_wait, binder_stop_on_user_error < 2); if (ret && ret != -ERESTARTSYS) pr_info("%d:%d ioctl %x %lx returned %d\n", proc->pid, current->pid, cmd, arg, ret); err_unlocked: trace_binder_ioctl_done(ret); return ret; } static void binder_vma_open(struct vm_area_struct *vma) { struct binder_proc *proc = vma->vm_private_data; binder_debug(BINDER_DEBUG_OPEN_CLOSE, "%d open vm area %lx-%lx (%ld K) vma %lx pagep %lx\n", proc->pid, vma->vm_start, vma->vm_end, (vma->vm_end - vma->vm_start) / SZ_1K, vma->vm_flags, (unsigned long)pgprot_val(vma->vm_page_prot)); } static void binder_vma_close(struct vm_area_struct *vma) { struct binder_proc *proc = vma->vm_private_data; binder_debug(BINDER_DEBUG_OPEN_CLOSE, "%d close vm area %lx-%lx (%ld K) vma %lx pagep %lx\n", proc->pid, vma->vm_start, vma->vm_end, (vma->vm_end - vma->vm_start) / SZ_1K, vma->vm_flags, (unsigned long)pgprot_val(vma->vm_page_prot)); binder_alloc_vma_close(&proc->alloc); } static vm_fault_t binder_vm_fault(struct vm_fault *vmf) { return VM_FAULT_SIGBUS; } static const struct vm_operations_struct binder_vm_ops = { .open = binder_vma_open, .close = binder_vma_close, .fault = binder_vm_fault, }; static int binder_mmap(struct file *filp, struct vm_area_struct *vma) { int ret; struct binder_proc *proc = filp->private_data; const char *failure_string; if (proc->tsk != current->group_leader) return -EINVAL; if ((vma->vm_end - vma->vm_start) > SZ_4M) vma->vm_end = vma->vm_start + SZ_4M; binder_debug(BINDER_DEBUG_OPEN_CLOSE, "%s: %d %lx-%lx (%ld K) vma %lx pagep %lx\n", __func__, proc->pid, vma->vm_start, vma->vm_end, (vma->vm_end - vma->vm_start) / SZ_1K, vma->vm_flags, (unsigned long)pgprot_val(vma->vm_page_prot)); if (vma->vm_flags & FORBIDDEN_MMAP_FLAGS) { ret = -EPERM; failure_string = "bad vm_flags"; goto err_bad_arg; } vma->vm_flags |= VM_DONTCOPY | VM_MIXEDMAP; vma->vm_flags &= ~VM_MAYWRITE; vma->vm_ops = &binder_vm_ops; vma->vm_private_data = proc; ret = binder_alloc_mmap_handler(&proc->alloc, vma); if (ret) return ret; return 0; err_bad_arg: pr_err("%s: %d %lx-%lx %s failed %d\n", __func__, proc->pid, vma->vm_start, vma->vm_end, failure_string, ret); return ret; } static int binder_open(struct inode *nodp, struct file *filp) { struct binder_proc *proc; struct binder_device *binder_dev; binder_debug(BINDER_DEBUG_OPEN_CLOSE, "%s: %d:%d\n", __func__, current->group_leader->pid, current->pid); proc = kzalloc(sizeof(*proc), GFP_KERNEL); if (proc == NULL) return -ENOMEM; spin_lock_init(&proc->inner_lock); spin_lock_init(&proc->outer_lock); get_task_struct(current->group_leader); proc->tsk = current->group_leader; INIT_LIST_HEAD(&proc->todo); proc->default_priority = task_nice(current); binder_dev = container_of(filp->private_data, struct binder_device, miscdev); proc->context = &binder_dev->context; binder_alloc_init(&proc->alloc); binder_stats_created(BINDER_STAT_PROC); proc->pid = current->group_leader->pid; INIT_LIST_HEAD(&proc->delivered_death); INIT_LIST_HEAD(&proc->waiting_threads); filp->private_data = proc; mutex_lock(&binder_procs_lock); hlist_add_head(&proc->proc_node, &binder_procs); mutex_unlock(&binder_procs_lock); if (binder_debugfs_dir_entry_proc) { char strbuf[11]; snprintf(strbuf, sizeof(strbuf), "%u", proc->pid); /* * proc debug entries are shared between contexts, so * this will fail if the process tries to open the driver * again with a different context. The priting code will * anyway print all contexts that a given PID has, so this * is not a problem. */ proc->debugfs_entry = debugfs_create_file(strbuf, 0444, binder_debugfs_dir_entry_proc, (void *)(unsigned long)proc->pid, &proc_fops); } return 0; } static int binder_flush(struct file *filp, fl_owner_t id) { struct binder_proc *proc = filp->private_data; binder_defer_work(proc, BINDER_DEFERRED_FLUSH); return 0; } static void binder_deferred_flush(struct binder_proc *proc) { struct rb_node *n; int wake_count = 0; binder_inner_proc_lock(proc); for (n = rb_first(&proc->threads); n != NULL; n = rb_next(n)) { struct binder_thread *thread = rb_entry(n, struct binder_thread, rb_node); thread->looper_need_return = true; if (thread->looper & BINDER_LOOPER_STATE_WAITING) { wake_up_interruptible(&thread->wait); wake_count++; } } binder_inner_proc_unlock(proc); binder_debug(BINDER_DEBUG_OPEN_CLOSE, "binder_flush: %d woke %d threads\n", proc->pid, wake_count); } static int binder_release(struct inode *nodp, struct file *filp) { struct binder_proc *proc = filp->private_data; debugfs_remove(proc->debugfs_entry); binder_defer_work(proc, BINDER_DEFERRED_RELEASE); return 0; } static int binder_node_release(struct binder_node *node, int refs) { struct binder_ref *ref; int death = 0; struct binder_proc *proc = node->proc; binder_release_work(proc, &node->async_todo); binder_node_lock(node); binder_inner_proc_lock(proc); binder_dequeue_work_ilocked(&node->work); /* * The caller must have taken a temporary ref on the node, */ BUG_ON(!node->tmp_refs); if (hlist_empty(&node->refs) && node->tmp_refs == 1) { binder_inner_proc_unlock(proc); binder_node_unlock(node); binder_free_node(node); return refs; } node->proc = NULL; node->local_strong_refs = 0; node->local_weak_refs = 0; binder_inner_proc_unlock(proc); spin_lock(&binder_dead_nodes_lock); hlist_add_head(&node->dead_node, &binder_dead_nodes); spin_unlock(&binder_dead_nodes_lock); hlist_for_each_entry(ref, &node->refs, node_entry) { refs++; /* * Need the node lock to synchronize * with new notification requests and the * inner lock to synchronize with queued * death notifications. */ binder_inner_proc_lock(ref->proc); if (!ref->death) { binder_inner_proc_unlock(ref->proc); continue; } death++; BUG_ON(!list_empty(&ref->death->work.entry)); ref->death->work.type = BINDER_WORK_DEAD_BINDER; binder_enqueue_work_ilocked(&ref->death->work, &ref->proc->todo); binder_wakeup_proc_ilocked(ref->proc); binder_inner_proc_unlock(ref->proc); } binder_debug(BINDER_DEBUG_DEAD_BINDER, "node %d now dead, refs %d, death %d\n", node->debug_id, refs, death); binder_node_unlock(node); binder_put_node(node); return refs; } static void binder_deferred_release(struct binder_proc *proc) { struct binder_context *context = proc->context; struct rb_node *n; int threads, nodes, incoming_refs, outgoing_refs, active_transactions; mutex_lock(&binder_procs_lock); hlist_del(&proc->proc_node); mutex_unlock(&binder_procs_lock); mutex_lock(&context->context_mgr_node_lock); if (context->binder_context_mgr_node && context->binder_context_mgr_node->proc == proc) { binder_debug(BINDER_DEBUG_DEAD_BINDER, "%s: %d context_mgr_node gone\n", __func__, proc->pid); context->binder_context_mgr_node = NULL; } mutex_unlock(&context->context_mgr_node_lock); binder_inner_proc_lock(proc); /* * Make sure proc stays alive after we * remove all the threads */ proc->tmp_ref++; proc->is_dead = true; threads = 0; active_transactions = 0; while ((n = rb_first(&proc->threads))) { struct binder_thread *thread; thread = rb_entry(n, struct binder_thread, rb_node); binder_inner_proc_unlock(proc); threads++; active_transactions += binder_thread_release(proc, thread); binder_inner_proc_lock(proc); } nodes = 0; incoming_refs = 0; while ((n = rb_first(&proc->nodes))) { struct binder_node *node; node = rb_entry(n, struct binder_node, rb_node); nodes++; /* * take a temporary ref on the node before * calling binder_node_release() which will either * kfree() the node or call binder_put_node() */ binder_inc_node_tmpref_ilocked(node); rb_erase(&node->rb_node, &proc->nodes); binder_inner_proc_unlock(proc); incoming_refs = binder_node_release(node, incoming_refs); binder_inner_proc_lock(proc); } binder_inner_proc_unlock(proc); outgoing_refs = 0; binder_proc_lock(proc); while ((n = rb_first(&proc->refs_by_desc))) { struct binder_ref *ref; ref = rb_entry(n, struct binder_ref, rb_node_desc); outgoing_refs++; binder_cleanup_ref_olocked(ref); binder_proc_unlock(proc); binder_free_ref(ref); binder_proc_lock(proc); } binder_proc_unlock(proc); binder_release_work(proc, &proc->todo); binder_release_work(proc, &proc->delivered_death); binder_debug(BINDER_DEBUG_OPEN_CLOSE, "%s: %d threads %d, nodes %d (ref %d), refs %d, active transactions %d\n", __func__, proc->pid, threads, nodes, incoming_refs, outgoing_refs, active_transactions); binder_proc_dec_tmpref(proc); } static void binder_deferred_func(struct work_struct *work) { struct binder_proc *proc; int defer; do { mutex_lock(&binder_deferred_lock); if (!hlist_empty(&binder_deferred_list)) { proc = hlist_entry(binder_deferred_list.first, struct binder_proc, deferred_work_node); hlist_del_init(&proc->deferred_work_node); defer = proc->deferred_work; proc->deferred_work = 0; } else { proc = NULL; defer = 0; } mutex_unlock(&binder_deferred_lock); if (defer & BINDER_DEFERRED_FLUSH) binder_deferred_flush(proc); if (defer & BINDER_DEFERRED_RELEASE) binder_deferred_release(proc); /* frees proc */ } while (proc); } static DECLARE_WORK(binder_deferred_work, binder_deferred_func); static void binder_defer_work(struct binder_proc *proc, enum binder_deferred_state defer) { mutex_lock(&binder_deferred_lock); proc->deferred_work |= defer; if (hlist_unhashed(&proc->deferred_work_node)) { hlist_add_head(&proc->deferred_work_node, &binder_deferred_list); schedule_work(&binder_deferred_work); } mutex_unlock(&binder_deferred_lock); } static void print_binder_transaction_ilocked(struct seq_file *m, struct binder_proc *proc, const char *prefix, struct binder_transaction *t) { struct binder_proc *to_proc; struct binder_buffer *buffer = t->buffer; spin_lock(&t->lock); to_proc = t->to_proc; seq_printf(m, "%s %d: %pK from %d:%d to %d:%d code %x flags %x pri %ld r%d", prefix, t->debug_id, t, t->from ? t->from->proc->pid : 0, t->from ? t->from->pid : 0, to_proc ? to_proc->pid : 0, t->to_thread ? t->to_thread->pid : 0, t->code, t->flags, t->priority, t->need_reply); spin_unlock(&t->lock); if (proc != to_proc) { /* * Can only safely deref buffer if we are holding the * correct proc inner lock for this node */ seq_puts(m, "\n"); return; } if (buffer == NULL) { seq_puts(m, " buffer free\n"); return; } if (buffer->target_node) seq_printf(m, " node %d", buffer->target_node->debug_id); seq_printf(m, " size %zd:%zd data %pK\n", buffer->data_size, buffer->offsets_size, buffer->data); } static void print_binder_work_ilocked(struct seq_file *m, struct binder_proc *proc, const char *prefix, const char *transaction_prefix, struct binder_work *w) { struct binder_node *node; struct binder_transaction *t; switch (w->type) { case BINDER_WORK_TRANSACTION: t = container_of(w, struct binder_transaction, work); print_binder_transaction_ilocked( m, proc, transaction_prefix, t); break; case BINDER_WORK_RETURN_ERROR: { struct binder_error *e = container_of( w, struct binder_error, work); seq_printf(m, "%stransaction error: %u\n", prefix, e->cmd); } break; case BINDER_WORK_TRANSACTION_COMPLETE: seq_printf(m, "%stransaction complete\n", prefix); break; case BINDER_WORK_NODE: node = container_of(w, struct binder_node, work); seq_printf(m, "%snode work %d: u%016llx c%016llx\n", prefix, node->debug_id, (u64)node->ptr, (u64)node->cookie); break; case BINDER_WORK_DEAD_BINDER: seq_printf(m, "%shas dead binder\n", prefix); break; case BINDER_WORK_DEAD_BINDER_AND_CLEAR: seq_printf(m, "%shas cleared dead binder\n", prefix); break; case BINDER_WORK_CLEAR_DEATH_NOTIFICATION: seq_printf(m, "%shas cleared death notification\n", prefix); break; default: seq_printf(m, "%sunknown work: type %d\n", prefix, w->type); break; } } static void print_binder_thread_ilocked(struct seq_file *m, struct binder_thread *thread, int print_always) { struct binder_transaction *t; struct binder_work *w; size_t start_pos = m->count; size_t header_pos; seq_printf(m, " thread %d: l %02x need_return %d tr %d\n", thread->pid, thread->looper, thread->looper_need_return, atomic_read(&thread->tmp_ref)); header_pos = m->count; t = thread->transaction_stack; while (t) { if (t->from == thread) { print_binder_transaction_ilocked(m, thread->proc, " outgoing transaction", t); t = t->from_parent; } else if (t->to_thread == thread) { print_binder_transaction_ilocked(m, thread->proc, " incoming transaction", t); t = t->to_parent; } else { print_binder_transaction_ilocked(m, thread->proc, " bad transaction", t); t = NULL; } } list_for_each_entry(w, &thread->todo, entry) { print_binder_work_ilocked(m, thread->proc, " ", " pending transaction", w); } if (!print_always && m->count == header_pos) m->count = start_pos; } static void print_binder_node_nilocked(struct seq_file *m, struct binder_node *node) { struct binder_ref *ref; struct binder_work *w; int count; count = 0; hlist_for_each_entry(ref, &node->refs, node_entry) count++; seq_printf(m, " node %d: u%016llx c%016llx hs %d hw %d ls %d lw %d is %d iw %d tr %d", node->debug_id, (u64)node->ptr, (u64)node->cookie, node->has_strong_ref, node->has_weak_ref, node->local_strong_refs, node->local_weak_refs, node->internal_strong_refs, count, node->tmp_refs); if (count) { seq_puts(m, " proc"); hlist_for_each_entry(ref, &node->refs, node_entry) seq_printf(m, " %d", ref->proc->pid); } seq_puts(m, "\n"); if (node->proc) { list_for_each_entry(w, &node->async_todo, entry) print_binder_work_ilocked(m, node->proc, " ", " pending async transaction", w); } } static void print_binder_ref_olocked(struct seq_file *m, struct binder_ref *ref) { binder_node_lock(ref->node); seq_printf(m, " ref %d: desc %d %snode %d s %d w %d d %pK\n", ref->data.debug_id, ref->data.desc, ref->node->proc ? "" : "dead ", ref->node->debug_id, ref->data.strong, ref->data.weak, ref->death); binder_node_unlock(ref->node); } static void print_binder_proc(struct seq_file *m, struct binder_proc *proc, int print_all) { struct binder_work *w; struct rb_node *n; size_t start_pos = m->count; size_t header_pos; struct binder_node *last_node = NULL; seq_printf(m, "proc %d\n", proc->pid); seq_printf(m, "context %s\n", proc->context->name); header_pos = m->count; binder_inner_proc_lock(proc); for (n = rb_first(&proc->threads); n != NULL; n = rb_next(n)) print_binder_thread_ilocked(m, rb_entry(n, struct binder_thread, rb_node), print_all); for (n = rb_first(&proc->nodes); n != NULL; n = rb_next(n)) { struct binder_node *node = rb_entry(n, struct binder_node, rb_node); /* * take a temporary reference on the node so it * survives and isn't removed from the tree * while we print it. */ binder_inc_node_tmpref_ilocked(node); /* Need to drop inner lock to take node lock */ binder_inner_proc_unlock(proc); if (last_node) binder_put_node(last_node); binder_node_inner_lock(node); print_binder_node_nilocked(m, node); binder_node_inner_unlock(node); last_node = node; binder_inner_proc_lock(proc); } binder_inner_proc_unlock(proc); if (last_node) binder_put_node(last_node); if (print_all) { binder_proc_lock(proc); for (n = rb_first(&proc->refs_by_desc); n != NULL; n = rb_next(n)) print_binder_ref_olocked(m, rb_entry(n, struct binder_ref, rb_node_desc)); binder_proc_unlock(proc); } binder_alloc_print_allocated(m, &proc->alloc); binder_inner_proc_lock(proc); list_for_each_entry(w, &proc->todo, entry) print_binder_work_ilocked(m, proc, " ", " pending transaction", w); list_for_each_entry(w, &proc->delivered_death, entry) { seq_puts(m, " has delivered dead binder\n"); break; } binder_inner_proc_unlock(proc); if (!print_all && m->count == header_pos) m->count = start_pos; } static const char * const binder_return_strings[] = { "BR_ERROR", "BR_OK", "BR_TRANSACTION", "BR_REPLY", "BR_ACQUIRE_RESULT", "BR_DEAD_REPLY", "BR_TRANSACTION_COMPLETE", "BR_INCREFS", "BR_ACQUIRE", "BR_RELEASE", "BR_DECREFS", "BR_ATTEMPT_ACQUIRE", "BR_NOOP", "BR_SPAWN_LOOPER", "BR_FINISHED", "BR_DEAD_BINDER", "BR_CLEAR_DEATH_NOTIFICATION_DONE", "BR_FAILED_REPLY" }; static const char * const binder_command_strings[] = { "BC_TRANSACTION", "BC_REPLY", "BC_ACQUIRE_RESULT", "BC_FREE_BUFFER", "BC_INCREFS", "BC_ACQUIRE", "BC_RELEASE", "BC_DECREFS", "BC_INCREFS_DONE", "BC_ACQUIRE_DONE", "BC_ATTEMPT_ACQUIRE", "BC_REGISTER_LOOPER", "BC_ENTER_LOOPER", "BC_EXIT_LOOPER", "BC_REQUEST_DEATH_NOTIFICATION", "BC_CLEAR_DEATH_NOTIFICATION", "BC_DEAD_BINDER_DONE", "BC_TRANSACTION_SG", "BC_REPLY_SG", }; static const char * const binder_objstat_strings[] = { "proc", "thread", "node", "ref", "death", "transaction", "transaction_complete" }; static void print_binder_stats(struct seq_file *m, const char *prefix, struct binder_stats *stats) { int i; BUILD_BUG_ON(ARRAY_SIZE(stats->bc) != ARRAY_SIZE(binder_command_strings)); for (i = 0; i < ARRAY_SIZE(stats->bc); i++) { int temp = atomic_read(&stats->bc[i]); if (temp) seq_printf(m, "%s%s: %d\n", prefix, binder_command_strings[i], temp); } BUILD_BUG_ON(ARRAY_SIZE(stats->br) != ARRAY_SIZE(binder_return_strings)); for (i = 0; i < ARRAY_SIZE(stats->br); i++) { int temp = atomic_read(&stats->br[i]); if (temp) seq_printf(m, "%s%s: %d\n", prefix, binder_return_strings[i], temp); } BUILD_BUG_ON(ARRAY_SIZE(stats->obj_created) != ARRAY_SIZE(binder_objstat_strings)); BUILD_BUG_ON(ARRAY_SIZE(stats->obj_created) != ARRAY_SIZE(stats->obj_deleted)); for (i = 0; i < ARRAY_SIZE(stats->obj_created); i++) { int created = atomic_read(&stats->obj_created[i]); int deleted = atomic_read(&stats->obj_deleted[i]); if (created || deleted) seq_printf(m, "%s%s: active %d total %d\n", prefix, binder_objstat_strings[i], created - deleted, created); } } static void print_binder_proc_stats(struct seq_file *m, struct binder_proc *proc) { struct binder_work *w; struct binder_thread *thread; struct rb_node *n; int count, strong, weak, ready_threads; size_t free_async_space = binder_alloc_get_free_async_space(&proc->alloc); seq_printf(m, "proc %d\n", proc->pid); seq_printf(m, "context %s\n", proc->context->name); count = 0; ready_threads = 0; binder_inner_proc_lock(proc); for (n = rb_first(&proc->threads); n != NULL; n = rb_next(n)) count++; list_for_each_entry(thread, &proc->waiting_threads, waiting_thread_node) ready_threads++; seq_printf(m, " threads: %d\n", count); seq_printf(m, " requested threads: %d+%d/%d\n" " ready threads %d\n" " free async space %zd\n", proc->requested_threads, proc->requested_threads_started, proc->max_threads, ready_threads, free_async_space); count = 0; for (n = rb_first(&proc->nodes); n != NULL; n = rb_next(n)) count++; binder_inner_proc_unlock(proc); seq_printf(m, " nodes: %d\n", count); count = 0; strong = 0; weak = 0; binder_proc_lock(proc); for (n = rb_first(&proc->refs_by_desc); n != NULL; n = rb_next(n)) { struct binder_ref *ref = rb_entry(n, struct binder_ref, rb_node_desc); count++; strong += ref->data.strong; weak += ref->data.weak; } binder_proc_unlock(proc); seq_printf(m, " refs: %d s %d w %d\n", count, strong, weak); count = binder_alloc_get_allocated_count(&proc->alloc); seq_printf(m, " buffers: %d\n", count); binder_alloc_print_pages(m, &proc->alloc); count = 0; binder_inner_proc_lock(proc); list_for_each_entry(w, &proc->todo, entry) { if (w->type == BINDER_WORK_TRANSACTION) count++; } binder_inner_proc_unlock(proc); seq_printf(m, " pending transactions: %d\n", count); print_binder_stats(m, " ", &proc->stats); } static int state_show(struct seq_file *m, void *unused) { struct binder_proc *proc; struct binder_node *node; struct binder_node *last_node = NULL; seq_puts(m, "binder state:\n"); spin_lock(&binder_dead_nodes_lock); if (!hlist_empty(&binder_dead_nodes)) seq_puts(m, "dead nodes:\n"); hlist_for_each_entry(node, &binder_dead_nodes, dead_node) { /* * take a temporary reference on the node so it * survives and isn't removed from the list * while we print it. */ node->tmp_refs++; spin_unlock(&binder_dead_nodes_lock); if (last_node) binder_put_node(last_node); binder_node_lock(node); print_binder_node_nilocked(m, node); binder_node_unlock(node); last_node = node; spin_lock(&binder_dead_nodes_lock); } spin_unlock(&binder_dead_nodes_lock); if (last_node) binder_put_node(last_node); mutex_lock(&binder_procs_lock); hlist_for_each_entry(proc, &binder_procs, proc_node) print_binder_proc(m, proc, 1); mutex_unlock(&binder_procs_lock); return 0; } static int stats_show(struct seq_file *m, void *unused) { struct binder_proc *proc; seq_puts(m, "binder stats:\n"); print_binder_stats(m, "", &binder_stats); mutex_lock(&binder_procs_lock); hlist_for_each_entry(proc, &binder_procs, proc_node) print_binder_proc_stats(m, proc); mutex_unlock(&binder_procs_lock); return 0; } static int transactions_show(struct seq_file *m, void *unused) { struct binder_proc *proc; seq_puts(m, "binder transactions:\n"); mutex_lock(&binder_procs_lock); hlist_for_each_entry(proc, &binder_procs, proc_node) print_binder_proc(m, proc, 0); mutex_unlock(&binder_procs_lock); return 0; } static int proc_show(struct seq_file *m, void *unused) { struct binder_proc *itr; int pid = (unsigned long)m->private; mutex_lock(&binder_procs_lock); hlist_for_each_entry(itr, &binder_procs, proc_node) { if (itr->pid == pid) { seq_puts(m, "binder proc state:\n"); print_binder_proc(m, itr, 1); } } mutex_unlock(&binder_procs_lock); return 0; } static void print_binder_transaction_log_entry(struct seq_file *m, struct binder_transaction_log_entry *e) { int debug_id = READ_ONCE(e->debug_id_done); /* * read barrier to guarantee debug_id_done read before * we print the log values */ smp_rmb(); seq_printf(m, "%d: %s from %d:%d to %d:%d context %s node %d handle %d size %d:%d ret %d/%d l=%d", e->debug_id, (e->call_type == 2) ? "reply" : ((e->call_type == 1) ? "async" : "call "), e->from_proc, e->from_thread, e->to_proc, e->to_thread, e->context_name, e->to_node, e->target_handle, e->data_size, e->offsets_size, e->return_error, e->return_error_param, e->return_error_line); /* * read-barrier to guarantee read of debug_id_done after * done printing the fields of the entry */ smp_rmb(); seq_printf(m, debug_id && debug_id == READ_ONCE(e->debug_id_done) ? "\n" : " (incomplete)\n"); } static int transaction_log_show(struct seq_file *m, void *unused) { struct binder_transaction_log *log = m->private; unsigned int log_cur = atomic_read(&log->cur); unsigned int count; unsigned int cur; int i; count = log_cur + 1; cur = count < ARRAY_SIZE(log->entry) && !log->full ? 0 : count % ARRAY_SIZE(log->entry); if (count > ARRAY_SIZE(log->entry) || log->full) count = ARRAY_SIZE(log->entry); for (i = 0; i < count; i++) { unsigned int index = cur++ % ARRAY_SIZE(log->entry); print_binder_transaction_log_entry(m, &log->entry[index]); } return 0; } static const struct file_operations binder_fops = { .owner = THIS_MODULE, .poll = binder_poll, .unlocked_ioctl = binder_ioctl, .compat_ioctl = binder_ioctl, .mmap = binder_mmap, .open = binder_open, .flush = binder_flush, .release = binder_release, }; DEFINE_SHOW_ATTRIBUTE(state); DEFINE_SHOW_ATTRIBUTE(stats); DEFINE_SHOW_ATTRIBUTE(transactions); DEFINE_SHOW_ATTRIBUTE(transaction_log); static int __init init_binder_device(const char *name) { int ret; struct binder_device *binder_device; binder_device = kzalloc(sizeof(*binder_device), GFP_KERNEL); if (!binder_device) return -ENOMEM; binder_device->miscdev.fops = &binder_fops; binder_device->miscdev.minor = MISC_DYNAMIC_MINOR; binder_device->miscdev.name = name; binder_device->context.binder_context_mgr_uid = INVALID_UID; binder_device->context.name = name; mutex_init(&binder_device->context.context_mgr_node_lock); ret = misc_register(&binder_device->miscdev); if (ret < 0) { kfree(binder_device); return ret; } hlist_add_head(&binder_device->hlist, &binder_devices); return ret; } static int __init binder_init(void) { int ret; char *device_name, *device_names, *device_tmp; struct binder_device *device; struct hlist_node *tmp; ret = binder_alloc_shrinker_init(); if (ret) return ret; atomic_set(&binder_transaction_log.cur, ~0U); atomic_set(&binder_transaction_log_failed.cur, ~0U); binder_debugfs_dir_entry_root = debugfs_create_dir("binder", NULL); if (binder_debugfs_dir_entry_root) binder_debugfs_dir_entry_proc = debugfs_create_dir("proc", binder_debugfs_dir_entry_root); if (binder_debugfs_dir_entry_root) { debugfs_create_file("state", 0444, binder_debugfs_dir_entry_root, NULL, &state_fops); debugfs_create_file("stats", 0444, binder_debugfs_dir_entry_root, NULL, &stats_fops); debugfs_create_file("transactions", 0444, binder_debugfs_dir_entry_root, NULL, &transactions_fops); debugfs_create_file("transaction_log", 0444, binder_debugfs_dir_entry_root, &binder_transaction_log, &transaction_log_fops); debugfs_create_file("failed_transaction_log", 0444, binder_debugfs_dir_entry_root, &binder_transaction_log_failed, &transaction_log_fops); } /* * Copy the module_parameter string, because we don't want to * tokenize it in-place. */ device_names = kstrdup(binder_devices_param, GFP_KERNEL); if (!device_names) { ret = -ENOMEM; goto err_alloc_device_names_failed; } device_tmp = device_names; while ((device_name = strsep(&device_tmp, ","))) { ret = init_binder_device(device_name); if (ret) goto err_init_binder_device_failed; } return ret; err_init_binder_device_failed: hlist_for_each_entry_safe(device, tmp, &binder_devices, hlist) { misc_deregister(&device->miscdev); hlist_del(&device->hlist); kfree(device); } kfree(device_names); err_alloc_device_names_failed: debugfs_remove_recursive(binder_debugfs_dir_entry_root); return ret; } device_initcall(binder_init); #define CREATE_TRACE_POINTS #include "binder_trace.h" MODULE_LICENSE("GPL v2");