FROMLIST: binder: refactor binder_pop_transaction
(from https://lkml.org/lkml/2017/6/29/754)
binder_pop_transaction needs to be split into 2 pieces to
to allow the proc lock to be held on entry to dequeue the
transaction stack, but no lock when kfree'ing the transaction.
Split into binder_pop_transaction_locked and binder_free_transaction
(the actual locks are still to be added).
Change-Id: I4b3d21d42ad54031f52cb94ab2b0152812747c38
Signed-off-by: Todd Kjos <tkjos@google.com>
diff --git a/drivers/android/binder.c b/drivers/android/binder.c
index 7e44710..3325bed 100644
--- a/drivers/android/binder.c
+++ b/drivers/android/binder.c
@@ -768,14 +768,16 @@
static void binder_pop_transaction(struct binder_thread *target_thread,
struct binder_transaction *t)
{
- if (target_thread) {
- 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;
- }
- t->need_reply = 0;
+ BUG_ON(!target_thread);
+ 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;
+}
+
+static void binder_free_transaction(struct binder_transaction *t)
+{
if (t->buffer)
t->buffer->transaction = NULL;
kfree(t);
@@ -808,6 +810,7 @@
binder_pop_transaction(target_thread, t);
target_thread->return_error = error_code;
wake_up_interruptible(&target_thread->wait);
+ binder_free_transaction(t);
} else {
pr_err("reply failed, target thread, %d:%d, has error code %d already\n",
target_thread->proc->pid,
@@ -822,7 +825,7 @@
"send failed reply for transaction %d, target dead\n",
t->debug_id);
- binder_pop_transaction(target_thread, t);
+ binder_free_transaction(t);
if (next == NULL) {
binder_debug(BINDER_DEBUG_DEAD_BINDER,
"reply failed, no target thread at root\n");
@@ -1806,6 +1809,7 @@
if (reply) {
BUG_ON(t->buffer->async_transaction != 0);
binder_pop_transaction(target_thread, in_reply_to);
+ binder_free_transaction(in_reply_to);
} else if (!(t->flags & TF_ONE_WAY)) {
BUG_ON(t->buffer->async_transaction != 0);
t->need_reply = 1;
@@ -2635,9 +2639,7 @@
t->to_thread = thread;
thread->transaction_stack = t;
} else {
- t->buffer->transaction = NULL;
- kfree(t);
- binder_stats_deleted(BINDER_STAT_TRANSACTION);
+ binder_free_transaction(t);
}
break;
}
@@ -2680,9 +2682,7 @@
binder_debug(BINDER_DEBUG_DEAD_TRANSACTION,
"undelivered transaction %d\n",
t->debug_id);
- t->buffer->transaction = NULL;
- kfree(t);
- binder_stats_deleted(BINDER_STAT_TRANSACTION);
+ binder_free_transaction(t);
}
} break;
case BINDER_WORK_TRANSACTION_COMPLETE: {