| // SPDX-License-Identifier: GPL-2.0-only |
| /* binder.c |
| * |
| * Android IPC Subsystem |
| * |
| * Copyright (C) 2007-2008 Google, Inc. |
| */ |
| |
| /* |
| * 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 <linux/fdtable.h> |
| #include <linux/file.h> |
| #include <linux/freezer.h> |
| #include <linux/fs.h> |
| #include <linux/list.h> |
| #include <linux/miscdevice.h> |
| #include <linux/module.h> |
| #include <linux/mutex.h> |
| #include <linux/nsproxy.h> |
| #include <linux/poll.h> |
| #include <linux/debugfs.h> |
| #include <linux/rbtree.h> |
| #include <linux/sched/signal.h> |
| #include <linux/sched/mm.h> |
| #include <linux/seq_file.h> |
| #include <linux/string.h> |
| #include <linux/uaccess.h> |
| #include <linux/pid_namespace.h> |
| #include <linux/security.h> |
| #include <linux/spinlock.h> |
| #include <linux/ratelimit.h> |
| #include <linux/syscalls.h> |
| #include <linux/task_work.h> |
| #include <linux/sizes.h> |
| #include <linux/ktime.h> |
| |
| #include <uapi/linux/android/binder.h> |
| |
| #include <linux/cacheflush.h> |
| |
| #include "binder_internal.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); |
| |
| #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); |
| |
| 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); |
| |
| static __printf(2, 3) void binder_debug(int mask, const char *format, ...) |
| { |
| struct va_format vaf; |
| va_list args; |
| |
| if (binder_debug_mask & mask) { |
| va_start(args, format); |
| vaf.va = &args; |
| vaf.fmt = format; |
| pr_info_ratelimited("%pV", &vaf); |
| va_end(args); |
| } |
| } |
| |
| #define binder_txn_error(x...) \ |
| binder_debug(BINDER_DEBUG_FAILED_TRANSACTION, x) |
| |
| static __printf(1, 2) void binder_user_error(const char *format, ...) |
| { |
| struct va_format vaf; |
| va_list args; |
| |
| if (binder_debug_mask & BINDER_DEBUG_USER_ERROR) { |
| va_start(args, format); |
| vaf.va = &args; |
| vaf.fmt = format; |
| pr_info_ratelimited("%pV", &vaf); |
| va_end(args); |
| } |
| |
| if (binder_stop_on_user_error) |
| binder_stop_on_user_error = 2; |
| } |
| |
| #define binder_set_extended_error(ee, _id, _command, _param) \ |
| do { \ |
| (ee)->id = _id; \ |
| (ee)->command = _command; \ |
| (ee)->param = _param; \ |
| } 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) |
| |
| 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; |
| char context_name[BINDERFS_MAX_NAME + 1]; |
| }; |
| |
| 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; |
| } |
| |
| enum binder_deferred_state { |
| BINDER_DEFERRED_FLUSH = 0x01, |
| BINDER_DEFERRED_RELEASE = 0x02, |
| }; |
| |
| 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, |
| }; |
| |
| /** |
| * 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_inner_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); |
| |
| /* (e)poll-based threads require an explicit wakeup signal when |
| * queuing their own work; they rely on these events to consume |
| * messages without I/O block. Without it, threads risk waiting |
| * indefinitely without handling the work. |
| */ |
| if (thread->looper & BINDER_LOOPER_STATE_POLL && |
| thread->pid == current->pid && !thread->process_todo) |
| wake_up_interruptible_sync(&thread->wait); |
| |
| 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; |
| } |
| |
| 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); |
| } |
| |
| 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); |
| node->txn_security_ctx = !!(flags & FLAT_BINDER_FLAG_TXN_SECURITY_CTX); |
| 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; |
| } |
| |
| /* Find the smallest unused descriptor the "slow way" */ |
| static u32 slow_desc_lookup_olocked(struct binder_proc *proc) |
| { |
| struct binder_ref *ref; |
| struct rb_node *n; |
| u32 desc; |
| |
| desc = 1; |
| for (n = rb_first(&proc->refs_by_desc); n; n = rb_next(n)) { |
| ref = rb_entry(n, struct binder_ref, rb_node_desc); |
| if (ref->data.desc > desc) |
| break; |
| desc = ref->data.desc + 1; |
| } |
| |
| return desc; |
| } |
| |
| /* |
| * Find an available reference descriptor ID. The proc->outer_lock might |
| * be released in the process, in which case -EAGAIN is returned and the |
| * @desc should be considered invalid. |
| */ |
| static int get_ref_desc_olocked(struct binder_proc *proc, |
| struct binder_node *node, |
| u32 *desc) |
| { |
| struct dbitmap *dmap = &proc->dmap; |
| unsigned long *new, bit; |
| unsigned int nbits; |
| |
| /* 0 is reserved for the context manager */ |
| if (node == proc->context->binder_context_mgr_node) { |
| *desc = 0; |
| return 0; |
| } |
| |
| if (!dbitmap_enabled(dmap)) { |
| *desc = slow_desc_lookup_olocked(proc); |
| return 0; |
| } |
| |
| if (dbitmap_acquire_first_zero_bit(dmap, &bit) == 0) { |
| *desc = bit; |
| return 0; |
| } |
| |
| /* |
| * The dbitmap is full and needs to grow. The proc->outer_lock |
| * is briefly released to allocate the new bitmap safely. |
| */ |
| nbits = dbitmap_grow_nbits(dmap); |
| binder_proc_unlock(proc); |
| new = bitmap_zalloc(nbits, GFP_KERNEL); |
| binder_proc_lock(proc); |
| dbitmap_grow(dmap, new, nbits); |
| |
| return -EAGAIN; |
| } |
| |
| /** |
| * 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_ref *ref; |
| struct rb_node *parent; |
| struct rb_node **p; |
| u32 desc; |
| |
| retry: |
| p = &proc->refs_by_node.rb_node; |
| parent = NULL; |
| 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; |
| |
| /* might release the proc->outer_lock */ |
| if (get_ref_desc_olocked(proc, node, &desc) == -EAGAIN) |
| goto retry; |
| |
| 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 = desc; |
| 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) |
| { |
| struct dbitmap *dmap = &ref->proc->dmap; |
| 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); |
| |
| if (dbitmap_enabled(dmap)) |
| dbitmap_clear_bit(dmap, ref->data.desc); |
| 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_olocked() - 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); |
| } |
| |
| /* shrink descriptor bitmap if needed */ |
| static void try_shrink_dmap(struct binder_proc *proc) |
| { |
| unsigned long *new; |
| int nbits; |
| |
| binder_proc_lock(proc); |
| nbits = dbitmap_shrink_nbits(&proc->dmap); |
| binder_proc_unlock(proc); |
| |
| if (!nbits) |
| return; |
| |
| new = bitmap_zalloc(nbits, GFP_KERNEL); |
| binder_proc_lock(proc); |
| dbitmap_shrink(&proc->dmap, new, nbits); |
| binder_proc_unlock(proc); |
| } |
| |
| /** |
| * 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); |
| try_shrink_dmap(proc); |
| } |
| 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; |
| if (ret && ref == new_ref) { |
| /* |
| * Cleanup the failed reference here as the target |
| * could now be dead and have already released its |
| * references by now. Calling on the new reference |
| * with strong=0 and a tmp_refs will not decrement |
| * the node. The new_ref gets kfree'd below. |
| */ |
| binder_cleanup_ref_olocked(new_ref); |
| ref = NULL; |
| } |
| |
| 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); |
| if (fixup->target_fd >= 0) |
| put_unused_fd(fixup->target_fd); |
| list_del(&fixup->fixup_entry); |
| kfree(fixup); |
| } |
| } |
| |
| static void binder_txn_latency_free(struct binder_transaction *t) |
| { |
| int from_proc, from_thread, to_proc, to_thread; |
| |
| spin_lock(&t->lock); |
| from_proc = t->from ? t->from->proc->pid : 0; |
| from_thread = t->from ? t->from->pid : 0; |
| to_proc = t->to_proc ? t->to_proc->pid : 0; |
| to_thread = t->to_thread ? t->to_thread->pid : 0; |
| spin_unlock(&t->lock); |
| |
| trace_binder_txn_latency_free(t, from_proc, from_thread, to_proc, to_thread); |
| } |
| |
| static void binder_free_transaction(struct binder_transaction *t) |
| { |
| struct binder_proc *target_proc = t->to_proc; |
| |
| if (target_proc) { |
| binder_inner_proc_lock(target_proc); |
| target_proc->outstanding_txns--; |
| if (target_proc->outstanding_txns < 0) |
| pr_warn("%s: Unexpected outstanding_txns %d\n", |
| __func__, target_proc->outstanding_txns); |
| if (!target_proc->outstanding_txns && target_proc->is_frozen) |
| wake_up_interruptible_all(&target_proc->freeze_wait); |
| if (t->buffer) |
| t->buffer->transaction = NULL; |
| binder_inner_proc_unlock(target_proc); |
| } |
| if (trace_binder_txn_latency_free_enabled()) |
| binder_txn_latency_free(t); |
| /* |
| * If the transaction has no target_proc, then |
| * t->buffer->transaction has already been cleared. |
| */ |
| 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; |
| } |
| __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_get_object() - gets object and checks for valid metadata |
| * @proc: binder_proc owning the buffer |
| * @u: sender's user pointer to base of buffer |
| * @buffer: binder_buffer that we're parsing. |
| * @offset: offset in the @buffer at which to validate an object. |
| * @object: struct binder_object to read into |
| * |
| * Copy the binder object at the given offset into @object. If @u is |
| * provided then the copy is from the sender's buffer. If not, then |
| * it is copied from the target's @buffer. |
| * |
| * Return: If there's a valid metadata object at @offset, the |
| * size of that object. Otherwise, it returns zero. The object |
| * is read into the struct binder_object pointed to by @object. |
| */ |
| static size_t binder_get_object(struct binder_proc *proc, |
| const void __user *u, |
| struct binder_buffer *buffer, |
| unsigned long offset, |
| struct binder_object *object) |
| { |
| size_t read_size; |
| struct binder_object_header *hdr; |
| size_t object_size = 0; |
| |
| read_size = min_t(size_t, sizeof(*object), buffer->data_size - offset); |
| if (offset > buffer->data_size || read_size < sizeof(*hdr) || |
| !IS_ALIGNED(offset, sizeof(u32))) |
| return 0; |
| |
| if (u) { |
| if (copy_from_user(object, u + offset, read_size)) |
| return 0; |
| } else { |
| if (binder_alloc_copy_from_buffer(&proc->alloc, object, buffer, |
| offset, read_size)) |
| return 0; |
| } |
| |
| /* Ok, now see if we read a complete object. */ |
| hdr = &object->hdr; |
| 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. |
| * @proc: binder_proc owning the buffer |
| * @b: binder_buffer containing the object |
| * @object: struct binder_object to read into |
| * @index: index in offset array at which the binder_buffer_object is |
| * located |
| * @start_offset: points to the start of the offset array |
| * @object_offsetp: offset of @object read from @b |
| * @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. |
| * If @object_offsetp is non-NULL, then the offset within |
| * @b is written to it. |
| */ |
| static struct binder_buffer_object *binder_validate_ptr( |
| struct binder_proc *proc, |
| struct binder_buffer *b, |
| struct binder_object *object, |
| binder_size_t index, |
| binder_size_t start_offset, |
| binder_size_t *object_offsetp, |
| binder_size_t num_valid) |
| { |
| size_t object_size; |
| binder_size_t object_offset; |
| unsigned long buffer_offset; |
| |
| if (index >= num_valid) |
| return NULL; |
| |
| buffer_offset = start_offset + sizeof(binder_size_t) * index; |
| if (binder_alloc_copy_from_buffer(&proc->alloc, &object_offset, |
| b, buffer_offset, |
| sizeof(object_offset))) |
| return NULL; |
| object_size = binder_get_object(proc, NULL, b, object_offset, object); |
| if (!object_size || object->hdr.type != BINDER_TYPE_PTR) |
| return NULL; |
| if (object_offsetp) |
| *object_offsetp = object_offset; |
| |
| return &object->bbo; |
| } |
| |
| /** |
| * binder_validate_fixup() - validates pointer/fd fixups happen in order. |
| * @proc: binder_proc owning the buffer |
| * @b: transaction buffer |
| * @objects_start_offset: offset to start of objects buffer |
| * @buffer_obj_offset: offset to binder_buffer_object in which to fix up |
| * @fixup_offset: start offset in @buffer to fix up |
| * @last_obj_offset: offset to last binder_buffer_object that we fixed |
| * @last_min_offset: minimum fixup offset in object at @last_obj_offset |
| * |
| * 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_proc *proc, |
| struct binder_buffer *b, |
| binder_size_t objects_start_offset, |
| binder_size_t buffer_obj_offset, |
| binder_size_t fixup_offset, |
| binder_size_t last_obj_offset, |
| binder_size_t last_min_offset) |
| { |
| if (!last_obj_offset) { |
| /* Nothing to fix up in */ |
| return false; |
| } |
| |
| while (last_obj_offset != buffer_obj_offset) { |
| unsigned long buffer_offset; |
| struct binder_object last_object; |
| struct binder_buffer_object *last_bbo; |
| size_t object_size = binder_get_object(proc, NULL, b, |
| last_obj_offset, |
| &last_object); |
| if (object_size != sizeof(*last_bbo)) |
| return false; |
| |
| last_bbo = &last_object.bbo; |
| /* |
| * Safe to retrieve the parent of last_obj, since it |
| * was already previously verified by the driver. |
| */ |
| if ((last_bbo->flags & BINDER_BUFFER_FLAG_HAS_PARENT) == 0) |
| return false; |
| last_min_offset = last_bbo->parent_offset + sizeof(uintptr_t); |
| buffer_offset = objects_start_offset + |
| sizeof(binder_size_t) * last_bbo->parent; |
| if (binder_alloc_copy_from_buffer(&proc->alloc, |
| &last_obj_offset, |
| b, buffer_offset, |
| sizeof(last_obj_offset))) |
| return false; |
| } |
| return (fixup_offset >= last_min_offset); |
| } |
| |
| /** |
| * struct binder_task_work_cb - for deferred close |
| * |
| * @twork: callback_head for task work |
| * @fd: fd to close |
| * |
| * Structure to pass task work to be handled after |
| * returning from binder_ioctl() via task_work_add(). |
| */ |
| struct binder_task_work_cb { |
| struct callback_head twork; |
| struct file *file; |
| }; |
| |
| /** |
| * binder_do_fd_close() - close list of file descriptors |
| * @twork: callback head for task work |
| * |
| * It is not safe to call ksys_close() during the binder_ioctl() |
| * function if there is a chance that binder's own file descriptor |
| * might be closed. This is to meet the requirements for using |
| * fdget() (see comments for __fget_light()). Therefore use |
| * task_work_add() to schedule the close operation once we have |
| * returned from binder_ioctl(). This function is a callback |
| * for that mechanism and does the actual ksys_close() on the |
| * given file descriptor. |
| */ |
| static void binder_do_fd_close(struct callback_head *twork) |
| { |
| struct binder_task_work_cb *twcb = container_of(twork, |
| struct binder_task_work_cb, twork); |
| |
| fput(twcb->file); |
| kfree(twcb); |
| } |
| |
| /** |
| * binder_deferred_fd_close() - schedule a close for the given file-descriptor |
| * @fd: file-descriptor to close |
| * |
| * See comments in binder_do_fd_close(). This function is used to schedule |
| * a file-descriptor to be closed after returning from binder_ioctl(). |
| */ |
| static void binder_deferred_fd_close(int fd) |
| { |
| struct binder_task_work_cb *twcb; |
| |
| twcb = kzalloc(sizeof(*twcb), GFP_KERNEL); |
| if (!twcb) |
| return; |
| init_task_work(&twcb->twork, binder_do_fd_close); |
| twcb->file = file_close_fd(fd); |
| if (twcb->file) { |
| // pin it until binder_do_fd_close(); see comments there |
| get_file(twcb->file); |
| filp_close(twcb->file, current->files); |
| task_work_add(current, &twcb->twork, TWA_RESUME); |
| } else { |
| kfree(twcb); |
| } |
| } |
| |
| static void binder_transaction_buffer_release(struct binder_proc *proc, |
| struct binder_thread *thread, |
| struct binder_buffer *buffer, |
| binder_size_t off_end_offset, |
| bool is_failure) |
| { |
| int debug_id = buffer->debug_id; |
| binder_size_t off_start_offset, buffer_offset; |
| |
| binder_debug(BINDER_DEBUG_TRANSACTION, |
| "%d buffer release %d, size %zd-%zd, failed at %llx\n", |
| proc->pid, buffer->debug_id, |
| buffer->data_size, buffer->offsets_size, |
| (unsigned long long)off_end_offset); |
| |
| if (buffer->target_node) |
| binder_dec_node(buffer->target_node, 1, 0); |
| |
| off_start_offset = ALIGN(buffer->data_size, sizeof(void *)); |
| |
| for (buffer_offset = off_start_offset; buffer_offset < off_end_offset; |
| buffer_offset += sizeof(binder_size_t)) { |
| struct binder_object_header *hdr; |
| size_t object_size = 0; |
| struct binder_object object; |
| binder_size_t object_offset; |
| |
| if (!binder_alloc_copy_from_buffer(&proc->alloc, &object_offset, |
| buffer, buffer_offset, |
| sizeof(object_offset))) |
| object_size = binder_get_object(proc, NULL, buffer, |
| object_offset, &object); |
| if (object_size == 0) { |
| pr_err("transaction release %d bad object at offset %lld, size %zd\n", |
| debug_id, (u64)object_offset, buffer->data_size); |
| continue; |
| } |
| hdr = &object.hdr; |
| 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 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. |
| */ |
| } 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; |
| struct binder_object ptr_object; |
| binder_size_t fda_offset; |
| size_t fd_index; |
| binder_size_t fd_buf_size; |
| binder_size_t num_valid; |
| |
| if (is_failure) { |
| /* |
| * The fd fixups have not been applied so no |
| * fds need to be closed. |
| */ |
| continue; |
| } |
| |
| num_valid = (buffer_offset - off_start_offset) / |
| sizeof(binder_size_t); |
| fda = to_binder_fd_array_object(hdr); |
| parent = binder_validate_ptr(proc, buffer, &ptr_object, |
| fda->parent, |
| off_start_offset, |
| NULL, |
| num_valid); |
| if (!parent) { |
| pr_err("transaction release %d bad parent offset\n", |
| debug_id); |
| continue; |
| } |
| 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; |
| } |
| /* |
| * the source data for binder_buffer_object is visible |
| * to user-space and the @buffer element is the user |
| * pointer to the buffer_object containing the fd_array. |
| * Convert the address to an offset relative to |
| * the base of the transaction buffer. |
| */ |
| fda_offset = parent->buffer - buffer->user_data + |
| fda->parent_offset; |
| for (fd_index = 0; fd_index < fda->num_fds; |
| fd_index++) { |
| u32 fd; |
| int err; |
| binder_size_t offset = fda_offset + |
| fd_index * sizeof(fd); |
| |
| err = binder_alloc_copy_from_buffer( |
| &proc->alloc, &fd, buffer, |
| offset, sizeof(fd)); |
| WARN_ON(err); |
| if (!err) { |
| binder_deferred_fd_close(fd); |
| /* |
| * Need to make sure the thread goes |
| * back to userspace to complete the |
| * deferred close |
| */ |
| if (thread) |
| thread->looper_need_return = true; |
| } |
| } |
| } break; |
| default: |
| pr_err("transaction release %d bad object type %x\n", |
| debug_id, hdr->type); |
| break; |
| } |
| } |
| } |
| |
| /* Clean up all the objects in the buffer */ |
| static inline void binder_release_entire_buffer(struct binder_proc *proc, |
| struct binder_thread *thread, |
| struct binder_buffer *buffer, |
| bool is_failure) |
| { |
| binder_size_t off_end_offset; |
| |
| off_end_offset = ALIGN(buffer->data_size, sizeof(void *)); |
| off_end_offset += buffer->offsets_size; |
| |
| binder_transaction_buffer_release(proc, thread, buffer, |
| off_end_offset, is_failure); |
| } |
| |
| 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->cred, target_proc->cred)) { |
| 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->cred, target_proc->cred)) { |
| 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 fd, binder_size_t fd_offset, |
| 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; |
| |
| 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->cred, target_proc->cred, 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 = fd_offset; |
| fixup->target_fd = -1; |
| 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; |
| } |
| |
| /** |
| * struct binder_ptr_fixup - data to be fixed-up in target buffer |
| * @offset offset in target buffer to fixup |
| * @skip_size bytes to skip in copy (fixup will be written later) |
| * @fixup_data data to write at fixup offset |
| * @node list node |
| * |
| * This is used for the pointer fixup list (pf) which is created and consumed |
| * during binder_transaction() and is only accessed locally. No |
| * locking is necessary. |
| * |
| * The list is ordered by @offset. |
| */ |
| struct binder_ptr_fixup { |
| binder_size_t offset; |
| size_t skip_size; |
| binder_uintptr_t fixup_data; |
| struct list_head node; |
| }; |
| |
| /** |
| * struct binder_sg_copy - scatter-gather data to be copied |
| * @offset offset in target buffer |
| * @sender_uaddr user address in source buffer |
| * @length bytes to copy |
| * @node list node |
| * |
| * This is used for the sg copy list (sgc) which is created and consumed |
| * during binder_transaction() and is only accessed locally. No |
| * locking is necessary. |
| * |
| * The list is ordered by @offset. |
| */ |
| struct binder_sg_copy { |
| binder_size_t offset; |
| const void __user *sender_uaddr; |
| size_t length; |
| struct list_head node; |
| }; |
| |
| /** |
| * binder_do_deferred_txn_copies() - copy and fixup scatter-gather data |
| * @alloc: binder_alloc associated with @buffer |
| * @buffer: binder buffer in target process |
| * @sgc_head: list_head of scatter-gather copy list |
| * @pf_head: list_head of pointer fixup list |
| * |
| * Processes all elements of @sgc_head, applying fixups from @pf_head |
| * and copying the scatter-gather data from the source process' user |
| * buffer to the target's buffer. It is expected that the list creation |
| * and processing all occurs during binder_transaction() so these lists |
| * are only accessed in local context. |
| * |
| * Return: 0=success, else -errno |
| */ |
| static int binder_do_deferred_txn_copies(struct binder_alloc *alloc, |
| struct binder_buffer *buffer, |
| struct list_head *sgc_head, |
| struct list_head *pf_head) |
| { |
| int ret = 0; |
| struct binder_sg_copy *sgc, *tmpsgc; |
| struct binder_ptr_fixup *tmppf; |
| struct binder_ptr_fixup *pf = |
| list_first_entry_or_null(pf_head, struct binder_ptr_fixup, |
| node); |
| |
| list_for_each_entry_safe(sgc, tmpsgc, sgc_head, node) { |
| size_t bytes_copied = 0; |
| |
| while (bytes_copied < sgc->length) { |
| size_t copy_size; |
| size_t bytes_left = sgc->length - bytes_copied; |
| size_t offset = sgc->offset + bytes_copied; |
| |
| /* |
| * We copy up to the fixup (pointed to by pf) |
| */ |
| copy_size = pf ? min(bytes_left, (size_t)pf->offset - offset) |
| : bytes_left; |
| if (!ret && copy_size) |
| ret = binder_alloc_copy_user_to_buffer( |
| alloc, buffer, |
| offset, |
| sgc->sender_uaddr + bytes_copied, |
| copy_size); |
| bytes_copied += copy_size; |
| if (copy_size != bytes_left) { |
| BUG_ON(!pf); |
| /* we stopped at a fixup offset */ |
| if (pf->skip_size) { |
| /* |
| * we are just skipping. This is for |
| * BINDER_TYPE_FDA where the translated |
| * fds will be fixed up when we get |
| * to target context. |
| */ |
| bytes_copied += pf->skip_size; |
| } else { |
| /* apply the fixup indicated by pf */ |
| if (!ret) |
| ret = binder_alloc_copy_to_buffer( |
| alloc, buffer, |
| pf->offset, |
| &pf->fixup_data, |
| sizeof(pf->fixup_data)); |
| bytes_copied += sizeof(pf->fixup_data); |
| } |
| list_del(&pf->node); |
| kfree(pf); |
| pf = list_first_entry_or_null(pf_head, |
| struct binder_ptr_fixup, node); |
| } |
| } |
| list_del(&sgc->node); |
| kfree(sgc); |
| } |
| list_for_each_entry_safe(pf, tmppf, pf_head, node) { |
| BUG_ON(pf->skip_size == 0); |
| list_del(&pf->node); |
| kfree(pf); |
| } |
| BUG_ON(!list_empty(sgc_head)); |
| |
| return ret > 0 ? -EINVAL : ret; |
| } |
| |
| /** |
| * binder_cleanup_deferred_txn_lists() - free specified lists |
| * @sgc_head: list_head of scatter-gather copy list |
| * @pf_head: list_head of pointer fixup list |
| * |
| * Called to clean up @sgc_head and @pf_head if there is an |
| * error. |
| */ |
| static void binder_cleanup_deferred_txn_lists(struct list_head *sgc_head, |
| struct list_head *pf_head) |
| { |
| struct binder_sg_copy *sgc, *tmpsgc; |
| struct binder_ptr_fixup *pf, *tmppf; |
| |
| list_for_each_entry_safe(sgc, tmpsgc, sgc_head, node) { |
| list_del(&sgc->node); |
| kfree(sgc); |
| } |
| list_for_each_entry_safe(pf, tmppf, pf_head, node) { |
| list_del(&pf->node); |
| kfree(pf); |
| } |
| } |
| |
| /** |
| * binder_defer_copy() - queue a scatter-gather buffer for copy |
| * @sgc_head: list_head of scatter-gather copy list |
| * @offset: binder buffer offset in target process |
| * @sender_uaddr: user address in source process |
| * @length: bytes to copy |
| * |
| * Specify a scatter-gather block to be copied. The actual copy must |
| * be deferred until all the needed fixups are identified and queued. |
| * Then the copy and fixups are done together so un-translated values |
| * from the source are never visible in the target buffer. |
| * |
| * We are guaranteed that repeated calls to this function will have |
| * monotonically increasing @offset values so the list will naturally |
| * be ordered. |
| * |
| * Return: 0=success, else -errno |
| */ |
| static int binder_defer_copy(struct list_head *sgc_head, binder_size_t offset, |
| const void __user *sender_uaddr, size_t length) |
| { |
| struct binder_sg_copy *bc = kzalloc(sizeof(*bc), GFP_KERNEL); |
| |
| if (!bc) |
| return -ENOMEM; |
| |
| bc->offset = offset; |
| bc->sender_uaddr = sender_uaddr; |
| bc->length = length; |
| INIT_LIST_HEAD(&bc->node); |
| |
| /* |
| * We are guaranteed that the deferred copies are in-order |
| * so just add to the tail. |
| */ |
| list_add_tail(&bc->node, sgc_head); |
| |
| return 0; |
| } |
| |
| /** |
| * binder_add_fixup() - queue a fixup to be applied to sg copy |
| * @pf_head: list_head of binder ptr fixup list |
| * @offset: binder buffer offset in target process |
| * @fixup: bytes to be copied for fixup |
| * @skip_size: bytes to skip when copying (fixup will be applied later) |
| * |
| * Add the specified fixup to a list ordered by @offset. When copying |
| * the scatter-gather buffers, the fixup will be copied instead of |
| * data from the source buffer. For BINDER_TYPE_FDA fixups, the fixup |
| * will be applied later (in target process context), so we just skip |
| * the bytes specified by @skip_size. If @skip_size is 0, we copy the |
| * value in @fixup. |
| * |
| * This function is called *mostly* in @offset order, but there are |
| * exceptions. Since out-of-order inserts are relatively uncommon, |
| * we insert the new element by searching backward from the tail of |
| * the list. |
| * |
| * Return: 0=success, else -errno |
| */ |
| static int binder_add_fixup(struct list_head *pf_head, binder_size_t offset, |
| binder_uintptr_t fixup, size_t skip_size) |
| { |
| struct binder_ptr_fixup *pf = kzalloc(sizeof(*pf), GFP_KERNEL); |
| struct binder_ptr_fixup *tmppf; |
| |
| if (!pf) |
| return -ENOMEM; |
| |
| pf->offset = offset; |
| pf->fixup_data = fixup; |
| pf->skip_size = skip_size; |
| INIT_LIST_HEAD(&pf->node); |
| |
| /* Fixups are *mostly* added in-order, but there are some |
| * exceptions. Look backwards through list for insertion point. |
| */ |
| list_for_each_entry_reverse(tmppf, pf_head, node) { |
| if (tmppf->offset < pf->offset) { |
| list_add(&pf->node, &tmppf->node); |
| return 0; |
| } |
| } |
| /* |
| * if we get here, then the new offset is the lowest so |
| * insert at the head |
| */ |
| list_add(&pf->node, pf_head); |
| return 0; |
| } |
| |
| static int binder_translate_fd_array(struct list_head *pf_head, |
| struct binder_fd_array_object *fda, |
| const void __user *sender_ubuffer, |
| struct binder_buffer_object *parent, |
| struct binder_buffer_object *sender_uparent, |
| struct binder_transaction *t, |
| struct binder_thread *thread, |
| struct binder_transaction *in_reply_to) |
| { |
| binder_size_t fdi, fd_buf_size; |
| binder_size_t fda_offset; |
| const void __user *sender_ufda_base; |
| struct binder_proc *proc = thread->proc; |
| int ret; |
| |
| if (fda->num_fds == 0) |
| return 0; |
| |
| 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; |
| } |
| /* |
| * the source data for binder_buffer_object is visible |
| * to user-space and the @buffer element is the user |
| * pointer to the buffer_object containing the fd_array. |
| * Convert the address to an offset relative to |
| * the base of the transaction buffer. |
| */ |
| fda_offset = parent->buffer - t->buffer->user_data + |
| fda->parent_offset; |
| sender_ufda_base = (void __user *)(uintptr_t)sender_uparent->buffer + |
| fda->parent_offset; |
| |
| if (!IS_ALIGNED((unsigned long)fda_offset, sizeof(u32)) || |
| !IS_ALIGNED((unsigned long)sender_ufda_base, sizeof(u32))) { |
| binder_user_error("%d:%d parent offset not aligned correctly.\n", |
| proc->pid, thread->pid); |
| return -EINVAL; |
| } |
| ret = binder_add_fixup(pf_head, fda_offset, 0, fda->num_fds * sizeof(u32)); |
| if (ret) |
| return ret; |
| |
| for (fdi = 0; fdi < fda->num_fds; fdi++) { |
| u32 fd; |
| binder_size_t offset = fda_offset + fdi * sizeof(fd); |
| binder_size_t sender_uoffset = fdi * sizeof(fd); |
| |
| ret = copy_from_user(&fd, sender_ufda_base + sender_uoffset, sizeof(fd)); |
| if (!ret) |
| ret = binder_translate_fd(fd, offset, t, thread, |
| in_reply_to); |
| if (ret) |
| return ret > 0 ? -EINVAL : ret; |
| } |
| return 0; |
| } |
| |
| static int binder_fixup_parent(struct list_head *pf_head, |
| struct binder_transaction *t, |
| struct binder_thread *thread, |
| struct binder_buffer_object *bp, |
| binder_size_t off_start_offset, |
| binder_size_t num_valid, |
| binder_size_t last_fixup_obj_off, |
| binder_size_t last_fixup_min_off) |
| { |
| struct binder_buffer_object *parent; |
| struct binder_buffer *b = t->buffer; |
| struct binder_proc *proc = thread->proc; |
| struct binder_proc *target_proc = t->to_proc; |
| struct binder_object object; |
| binder_size_t buffer_offset; |
| binder_size_t parent_offset; |
| |
| if (!(bp->flags & BINDER_BUFFER_FLAG_HAS_PARENT)) |
| return 0; |
| |
| parent = binder_validate_ptr(target_proc, b, &object, bp->parent, |
| off_start_offset, &parent_offset, |
| 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(target_proc, b, off_start_offset, |
| parent_offset, bp->parent_offset, |
| last_fixup_obj_off, |
| 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; |
| } |
| |
| buffer_offset = bp->parent_offset + parent->buffer - b->user_data; |
| |
| return binder_add_fixup(pf_head, buffer_offset, bp->buffer, 0); |
| } |
| |
| /** |
| * binder_can_update_transaction() - Can a txn be superseded by an updated one? |
| * @t1: the pending async txn in the frozen process |
| * @t2: the new async txn to supersede the outdated pending one |
| * |
| * Return: true if t2 can supersede t1 |
| * false if t2 can not supersede t1 |
| */ |
| static bool binder_can_update_transaction(struct binder_transaction *t1, |
| struct binder_transaction *t2) |
| { |
| if ((t1->flags & t2->flags & (TF_ONE_WAY | TF_UPDATE_TXN)) != |
| (TF_ONE_WAY | TF_UPDATE_TXN) || !t1->to_proc || !t2->to_proc) |
| return false; |
| if (t1->to_proc->tsk == t2->to_proc->tsk && t1->code == t2->code && |
| t1->flags == t2->flags && t1->buffer->pid == t2->buffer->pid && |
| t1->buffer->target_node->ptr == t2->buffer->target_node->ptr && |
| t1->buffer->target_node->cookie == t2->buffer->target_node->cookie) |
| return true; |
| return false; |
| } |
| |
| /** |
| * binder_find_outdated_transaction_ilocked() - Find the outdated transaction |
| * @t: new async transaction |
| * @target_list: list to find outdated transaction |
| * |
| * Return: the outdated transaction if found |
| * NULL if no outdated transacton can be found |
| * |
| * Requires the proc->inner_lock to be held. |
| */ |
| static struct binder_transaction * |
| binder_find_outdated_transaction_ilocked(struct binder_transaction *t, |
| struct list_head *target_list) |
| { |
| struct binder_work *w; |
| |
| list_for_each_entry(w, target_list, entry) { |
| struct binder_transaction *t_queued; |
| |
| if (w->type != BINDER_WORK_TRANSACTION) |
| continue; |
| t_queued = container_of(w, struct binder_transaction, work); |
| if (binder_can_update_transaction(t_queued, t)) |
| return t_queued; |
| } |
| return NULL; |
| } |
| |
| /** |
| * 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: 0 if the transaction was successfully queued |
| * BR_DEAD_REPLY if the target process or thread is dead |
| * BR_FROZEN_REPLY if the target process or thread is frozen and |
| * the sync transaction was rejected |
| * BR_TRANSACTION_PENDING_FROZEN if the target process is frozen |
| * and the async transaction was successfully queued |
| */ |
| static int 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; |
| struct binder_transaction *t_outdated = NULL; |
| bool frozen = 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_frozen) { |
| frozen = true; |
| proc->sync_recv |= !oneway; |
| proc->async_recv |= oneway; |
| } |
| |
| if ((frozen && !oneway) || proc->is_dead || |
| (thread && thread->is_dead)) { |
| binder_inner_proc_unlock(proc); |
| binder_node_unlock(node); |
| return frozen ? BR_FROZEN_REPLY : BR_DEAD_REPLY; |
| } |
| |
| 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 { |
| if ((t->flags & TF_UPDATE_TXN) && frozen) { |
| t_outdated = binder_find_outdated_transaction_ilocked(t, |
| &node->async_todo); |
| if (t_outdated) { |
| binder_debug(BINDER_DEBUG_TRANSACTION, |
| "txn %d supersedes %d\n", |
| t->debug_id, t_outdated->debug_id); |
| list_del_init(&t_outdated->work.entry); |
| proc->outstanding_txns--; |
| } |
| } |
| binder_enqueue_work_ilocked(&t->work, &node->async_todo); |
| } |
| |
| if (!pending_async) |
| binder_wakeup_thread_ilocked(proc, thread, !oneway /* sync */); |
| |
| proc->outstanding_txns++; |
| binder_inner_proc_unlock(proc); |
| binder_node_unlock(node); |
| |
| /* |
| * To reduce potential contention, free the outdated transaction and |
| * buffer after releasing the locks. |
| */ |
| if (t_outdated) { |
| struct binder_buffer *buffer = t_outdated->buffer; |
| |
| t_outdated->buffer = NULL; |
| buffer->transaction = NULL; |
| trace_binder_transaction_update_buffer_release(buffer); |
| binder_release_entire_buffer(proc, NULL, buffer, false); |
| binder_alloc_free_buf(&proc->alloc, buffer); |
| kfree(t_outdated); |
| binder_stats_deleted(BINDER_STAT_TRANSACTION); |
| } |
| |
| if (oneway && frozen) |
| return BR_TRANSACTION_PENDING_FROZEN; |
| |
| return 0; |
| } |
| |
| /** |
| * binder_get_node_refs_for_txn() - Get required refs on node for txn |
| * @node: struct binder_node for which to get refs |
| * @procp: returns @node->proc if valid |
| * @error: if no @procp 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 @procp 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_set_txn_from_error(struct binder_transaction *t, int id, |
| uint32_t command, int32_t param) |
| { |
| struct binder_thread *from = binder_get_txn_from_and_acq_inner(t); |
| |
| if (!from) { |
| /* annotation for sparse */ |
| __release(&from->proc->inner_lock); |
| return; |
| } |
| |
| /* don't override existing errors */ |
| if (from->ee.command == BR_OK) |
| binder_set_extended_error(&from->ee, id, command, param); |
| binder_inner_proc_unlock(from->proc); |
| binder_thread_dec_tmpref(from); |
| } |
| |
| 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 buffer_offset = 0; |
| binder_size_t off_start_offset, off_end_offset; |
| binder_size_t off_min; |
| binder_size_t sg_buf_offset, sg_buf_end_offset; |
| binder_size_t user_offset = 0; |
| 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; |
| binder_size_t last_fixup_obj_off = 0; |
| binder_size_t last_fixup_min_off = 0; |
| struct binder_context *context = proc->context; |
| int t_debug_id = atomic_inc_return(&binder_last_id); |
| ktime_t t_start_time = ktime_get(); |
| char *secctx = NULL; |
| u32 secctx_sz = 0; |
| struct list_head sgc_head; |
| struct list_head pf_head; |
| const void __user *user_buffer = (const void __user *) |
| (uintptr_t)tr->data.ptr.buffer; |
| INIT_LIST_HEAD(&sgc_head); |
| INIT_LIST_HEAD(&pf_head); |
| |
| 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; |
| strscpy(e->context_name, proc->context->name, BINDERFS_MAX_NAME); |
| |
| binder_inner_proc_lock(proc); |
| binder_set_extended_error(&thread->ee, t_debug_id, BR_OK, 0); |
| binder_inner_proc_unlock(proc); |
| |
| 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); |
| binder_txn_error("%d:%d reply target not found\n", |
| thread->pid, proc->pid); |
| 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, %u\n", |
| proc->pid, thread->pid, tr->target.handle); |
| 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->pid == proc->pid) { |
| 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) { |
| binder_txn_error("%d:%d cannot find target node\n", |
| thread->pid, proc->pid); |
| /* |
| * 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 (WARN_ON(proc == target_proc)) { |
| binder_txn_error("%d:%d self transactions not allowed\n", |
| thread->pid, proc->pid); |
| return_error = BR_FAILED_REPLY; |
| return_error_param = -EINVAL; |
| return_error_line = __LINE__; |
| goto err_invalid_target_handle; |
| } |
| if (security_binder_transaction(proc->cred, |
| target_proc->cred) < 0) { |
| binder_txn_error("%d:%d transaction credentials failed\n", |
| thread->pid, proc->pid); |
| 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
|