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path: root/drivers/android/binder.c
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Diffstat (limited to 'drivers/android/binder.c')
-rw-r--r--drivers/android/binder.c196
1 files changed, 135 insertions, 61 deletions
diff --git a/drivers/android/binder.c b/drivers/android/binder.c
index cc89d0d2b965..d21040c5d343 100644
--- a/drivers/android/binder.c
+++ b/drivers/android/binder.c
@@ -141,7 +141,7 @@ enum {
};
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, S_IWUSR | S_IRUGO);
+module_param_named(debug_mask, binder_debug_mask, uint, 0644);
static char *binder_devices_param = CONFIG_ANDROID_BINDER_DEVICES;
module_param_named(devices, binder_devices_param, charp, 0444);
@@ -160,7 +160,7 @@ static int binder_set_stop_on_user_error(const char *val,
return ret;
}
module_param_call(stop_on_user_error, binder_set_stop_on_user_error,
- param_get_int, &binder_stop_on_user_error, S_IWUSR | S_IRUGO);
+ param_get_int, &binder_stop_on_user_error, 0644);
#define binder_debug(mask, x...) \
do { \
@@ -249,7 +249,7 @@ static struct binder_transaction_log_entry *binder_transaction_log_add(
unsigned int cur = atomic_inc_return(&log->cur);
if (cur >= ARRAY_SIZE(log->entry))
- log->full = 1;
+ log->full = true;
e = &log->entry[cur % ARRAY_SIZE(log->entry)];
WRITE_ONCE(e->debug_id_done, 0);
/*
@@ -493,8 +493,6 @@ enum binder_deferred_state {
* (protected by @inner_lock)
* @todo: list of work for this process
* (protected by @inner_lock)
- * @wait: wait queue head to wait for proc work
- * (invariant after initialized)
* @stats: per-process binder statistics
* (atomics, no lock needed)
* @delivered_death: list of delivered death notification
@@ -537,7 +535,6 @@ struct binder_proc {
bool is_dead;
struct list_head todo;
- wait_queue_head_t wait;
struct binder_stats stats;
struct list_head delivered_death;
int max_threads;
@@ -579,6 +576,8 @@ enum {
* (protected by @proc->inner_lock)
* @todo: list of work to do for this thread
* (protected by @proc->inner_lock)
+ * @process_todo: whether work in @todo should be processed
+ * (protected by @proc->inner_lock)
* @return_error: transaction errors reported by this thread
* (only accessed by this thread)
* @reply_error: transaction errors reported by target thread
@@ -604,6 +603,7 @@ struct binder_thread {
bool looper_need_return; /* can be written by other thread */
struct binder_transaction *transaction_stack;
struct list_head todo;
+ bool process_todo;
struct binder_error return_error;
struct binder_error reply_error;
wait_queue_head_t wait;
@@ -789,6 +789,16 @@ static bool binder_worklist_empty(struct binder_proc *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)
@@ -799,22 +809,56 @@ binder_enqueue_work_ilocked(struct binder_work *work,
}
/**
- * binder_enqueue_work() - Add an item to the work list
- * @proc: binder_proc associated with 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
- * @target_list: list to add work to
*
- * Adds the work to the specified list. Asserts that work
- * is not already on a 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_work(struct binder_proc *proc,
- struct binder_work *work,
- struct list_head *target_list)
+binder_enqueue_deferred_thread_work_ilocked(struct binder_thread *thread,
+ struct binder_work *work)
{
- binder_inner_proc_lock(proc);
- binder_enqueue_work_ilocked(work, target_list);
- binder_inner_proc_unlock(proc);
+ 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)
+{
+ binder_enqueue_work_ilocked(work, &thread->todo);
+ thread->process_todo = true;
+}
+
+/**
+ * binder_enqueue_thread_work() - Add an item to the thread work list
+ * @thread: thread to queue work to
+ * @work: struct binder_work to add to list
+ *
+ * Adds the work to the todo list of the thread, and enables processing
+ * of the todo queue.
+ */
+static void
+binder_enqueue_thread_work(struct binder_thread *thread,
+ struct binder_work *work)
+{
+ binder_inner_proc_lock(thread->proc);
+ binder_enqueue_thread_work_ilocked(thread, work);
+ binder_inner_proc_unlock(thread->proc);
}
static void
@@ -940,7 +984,7 @@ err:
static bool binder_has_work_ilocked(struct binder_thread *thread,
bool do_proc_work)
{
- return !binder_worklist_empty_ilocked(&thread->todo) ||
+ return thread->process_todo ||
thread->looper_need_return ||
(do_proc_work &&
!binder_worklist_empty_ilocked(&thread->proc->todo));
@@ -1228,6 +1272,17 @@ static int binder_inc_node_nilocked(struct binder_node *node, int strong,
node->local_strong_refs++;
if (!node->has_strong_ref && target_list) {
binder_dequeue_work_ilocked(&node->work);
+ /*
+ * Note: this function is the only place where we queue
+ * directly to a thread->todo without using the
+ * corresponding binder_enqueue_thread_work() helper
+ * functions; in this case it's ok to not set the
+ * process_todo flag, since we know this node work will
+ * always be followed by other work that starts queue
+ * processing: in case of synchronous transactions, a
+ * BR_REPLY or BR_ERROR; in case of oneway
+ * transactions, a BR_TRANSACTION_COMPLETE.
+ */
binder_enqueue_work_ilocked(&node->work, target_list);
}
} else {
@@ -1239,6 +1294,9 @@ static int binder_inc_node_nilocked(struct binder_node *node, int strong,
node->debug_id);
return -EINVAL;
}
+ /*
+ * See comment above
+ */
binder_enqueue_work_ilocked(&node->work, target_list);
}
}
@@ -1928,9 +1986,9 @@ static void binder_send_failed_reply(struct binder_transaction *t,
binder_pop_transaction_ilocked(target_thread, t);
if (target_thread->reply_error.cmd == BR_OK) {
target_thread->reply_error.cmd = error_code;
- binder_enqueue_work_ilocked(
- &target_thread->reply_error.work,
- &target_thread->todo);
+ binder_enqueue_thread_work_ilocked(
+ target_thread,
+ &target_thread->reply_error.work);
wake_up_interruptible(&target_thread->wait);
} else {
WARN(1, "Unexpected reply error: %u\n",
@@ -2569,20 +2627,18 @@ static bool binder_proc_transaction(struct binder_transaction *t,
struct binder_proc *proc,
struct binder_thread *thread)
{
- struct list_head *target_list = NULL;
struct binder_node *node = t->buffer->target_node;
bool oneway = !!(t->flags & TF_ONE_WAY);
- bool wakeup = true;
+ bool pending_async = false;
BUG_ON(!node);
binder_node_lock(node);
if (oneway) {
BUG_ON(thread);
if (node->has_async_transaction) {
- target_list = &node->async_todo;
- wakeup = false;
+ pending_async = true;
} else {
- node->has_async_transaction = 1;
+ node->has_async_transaction = true;
}
}
@@ -2594,19 +2650,17 @@ static bool binder_proc_transaction(struct binder_transaction *t,
return false;
}
- if (!thread && !target_list)
+ if (!thread && !pending_async)
thread = binder_select_thread_ilocked(proc);
if (thread)
- target_list = &thread->todo;
- else if (!target_list)
- target_list = &proc->todo;
+ binder_enqueue_thread_work_ilocked(thread, &t->work);
+ else if (!pending_async)
+ binder_enqueue_work_ilocked(&t->work, &proc->todo);
else
- BUG_ON(target_list != &node->async_todo);
+ binder_enqueue_work_ilocked(&t->work, &node->async_todo);
- binder_enqueue_work_ilocked(&t->work, target_list);
-
- if (wakeup)
+ if (!pending_async)
binder_wakeup_thread_ilocked(proc, thread, !oneway /* sync */);
binder_inner_proc_unlock(proc);
@@ -3101,10 +3155,10 @@ static void binder_transaction(struct binder_proc *proc,
}
}
tcomplete->type = BINDER_WORK_TRANSACTION_COMPLETE;
- binder_enqueue_work(proc, tcomplete, &thread->todo);
t->work.type = BINDER_WORK_TRANSACTION;
if (reply) {
+ binder_enqueue_thread_work(thread, tcomplete);
binder_inner_proc_lock(target_proc);
if (target_thread->is_dead) {
binder_inner_proc_unlock(target_proc);
@@ -3112,13 +3166,21 @@ static void binder_transaction(struct binder_proc *proc,
}
BUG_ON(t->buffer->async_transaction != 0);
binder_pop_transaction_ilocked(target_thread, in_reply_to);
- binder_enqueue_work_ilocked(&t->work, &target_thread->todo);
+ binder_enqueue_thread_work_ilocked(target_thread, &t->work);
binder_inner_proc_unlock(target_proc);
wake_up_interruptible_sync(&target_thread->wait);
binder_free_transaction(in_reply_to);
} else if (!(t->flags & TF_ONE_WAY)) {
BUG_ON(t->buffer->async_transaction != 0);
binder_inner_proc_lock(proc);
+ /*
+ * Defer the TRANSACTION_COMPLETE, so we don't return to
+ * userspace immediately; this allows the target process to
+ * immediately start processing this transaction, reducing
+ * latency. We will then return the TRANSACTION_COMPLETE when
+ * the target replies (or there is an error).
+ */
+ binder_enqueue_deferred_thread_work_ilocked(thread, tcomplete);
t->need_reply = 1;
t->from_parent = thread->transaction_stack;
thread->transaction_stack = t;
@@ -3132,6 +3194,7 @@ static void binder_transaction(struct binder_proc *proc,
} else {
BUG_ON(target_node == NULL);
BUG_ON(t->buffer->async_transaction != 1);
+ binder_enqueue_thread_work(thread, tcomplete);
if (!binder_proc_transaction(t, target_proc, NULL))
goto err_dead_proc_or_thread;
}
@@ -3210,15 +3273,11 @@ err_invalid_target_handle:
BUG_ON(thread->return_error.cmd != BR_OK);
if (in_reply_to) {
thread->return_error.cmd = BR_TRANSACTION_COMPLETE;
- binder_enqueue_work(thread->proc,
- &thread->return_error.work,
- &thread->todo);
+ binder_enqueue_thread_work(thread, &thread->return_error.work);
binder_send_failed_reply(in_reply_to, return_error);
} else {
thread->return_error.cmd = return_error;
- binder_enqueue_work(thread->proc,
- &thread->return_error.work,
- &thread->todo);
+ binder_enqueue_thread_work(thread, &thread->return_error.work);
}
}
@@ -3424,7 +3483,7 @@ static int binder_thread_write(struct binder_proc *proc,
w = binder_dequeue_work_head_ilocked(
&buf_node->async_todo);
if (!w) {
- buf_node->has_async_transaction = 0;
+ buf_node->has_async_transaction = false;
} else {
binder_enqueue_work_ilocked(
w, &proc->todo);
@@ -3522,10 +3581,9 @@ static int binder_thread_write(struct binder_proc *proc,
WARN_ON(thread->return_error.cmd !=
BR_OK);
thread->return_error.cmd = BR_ERROR;
- binder_enqueue_work(
- thread->proc,
- &thread->return_error.work,
- &thread->todo);
+ binder_enqueue_thread_work(
+ thread,
+ &thread->return_error.work);
binder_debug(
BINDER_DEBUG_FAILED_TRANSACTION,
"%d:%d BC_REQUEST_DEATH_NOTIFICATION failed\n",
@@ -3605,9 +3663,9 @@ static int binder_thread_write(struct binder_proc *proc,
if (thread->looper &
(BINDER_LOOPER_STATE_REGISTERED |
BINDER_LOOPER_STATE_ENTERED))
- binder_enqueue_work_ilocked(
- &death->work,
- &thread->todo);
+ binder_enqueue_thread_work_ilocked(
+ thread,
+ &death->work);
else {
binder_enqueue_work_ilocked(
&death->work,
@@ -3662,8 +3720,8 @@ static int binder_thread_write(struct binder_proc *proc,
if (thread->looper &
(BINDER_LOOPER_STATE_REGISTERED |
BINDER_LOOPER_STATE_ENTERED))
- binder_enqueue_work_ilocked(
- &death->work, &thread->todo);
+ binder_enqueue_thread_work_ilocked(
+ thread, &death->work);
else {
binder_enqueue_work_ilocked(
&death->work,
@@ -3837,6 +3895,8 @@ retry:
break;
}
w = binder_dequeue_work_head_ilocked(list);
+ if (binder_worklist_empty_ilocked(&thread->todo))
+ thread->process_todo = false;
switch (w->type) {
case BINDER_WORK_TRANSACTION: {
@@ -4302,6 +4362,18 @@ static int binder_thread_release(struct binder_proc *proc,
if (t)
spin_lock(&t->lock);
}
+
+ /*
+ * If this thread used poll, make sure we remove the waitqueue
+ * from any epoll data structures holding it with POLLFREE.
+ * waitqueue_active() is safe to use here because we're holding
+ * the inner lock.
+ */
+ if ((thread->looper & BINDER_LOOPER_STATE_POLL) &&
+ waitqueue_active(&thread->wait)) {
+ wake_up_poll(&thread->wait, POLLHUP | POLLFREE);
+ }
+
binder_inner_proc_unlock(thread->proc);
if (send_reply)
@@ -4646,7 +4718,7 @@ static int binder_mmap(struct file *filp, struct vm_area_struct *vma)
return 0;
err_bad_arg:
- pr_err("binder_mmap: %d %lx-%lx %s failed %d\n",
+ pr_err("%s: %d %lx-%lx %s failed %d\n", __func__,
proc->pid, vma->vm_start, vma->vm_end, failure_string, ret);
return ret;
}
@@ -4656,7 +4728,7 @@ static int binder_open(struct inode *nodp, struct file *filp)
struct binder_proc *proc;
struct binder_device *binder_dev;
- binder_debug(BINDER_DEBUG_OPEN_CLOSE, "binder_open: %d:%d\n",
+ binder_debug(BINDER_DEBUG_OPEN_CLOSE, "%s: %d:%d\n", __func__,
current->group_leader->pid, current->pid);
proc = kzalloc(sizeof(*proc), GFP_KERNEL);
@@ -4695,7 +4767,7 @@ static int binder_open(struct inode *nodp, struct file *filp)
* anyway print all contexts that a given PID has, so this
* is not a problem.
*/
- proc->debugfs_entry = debugfs_create_file(strbuf, S_IRUGO,
+ proc->debugfs_entry = debugfs_create_file(strbuf, 0444,
binder_debugfs_dir_entry_proc,
(void *)(unsigned long)proc->pid,
&binder_proc_fops);
@@ -5524,7 +5596,9 @@ static int __init binder_init(void)
struct binder_device *device;
struct hlist_node *tmp;
- binder_alloc_shrinker_init();
+ ret = binder_alloc_shrinker_init();
+ if (ret)
+ return ret;
atomic_set(&binder_transaction_log.cur, ~0U);
atomic_set(&binder_transaction_log_failed.cur, ~0U);
@@ -5536,27 +5610,27 @@ static int __init binder_init(void)
if (binder_debugfs_dir_entry_root) {
debugfs_create_file("state",
- S_IRUGO,
+ 0444,
binder_debugfs_dir_entry_root,
NULL,
&binder_state_fops);
debugfs_create_file("stats",
- S_IRUGO,
+ 0444,
binder_debugfs_dir_entry_root,
NULL,
&binder_stats_fops);
debugfs_create_file("transactions",
- S_IRUGO,
+ 0444,
binder_debugfs_dir_entry_root,
NULL,
&binder_transactions_fops);
debugfs_create_file("transaction_log",
- S_IRUGO,
+ 0444,
binder_debugfs_dir_entry_root,
&binder_transaction_log,
&binder_transaction_log_fops);
debugfs_create_file("failed_transaction_log",
- S_IRUGO,
+ 0444,
binder_debugfs_dir_entry_root,
&binder_transaction_log_failed,
&binder_transaction_log_fops);