When initiating a transaction, the target_node must
have a strong ref on it. Then we take a second
strong ref to make sure the node survives until the
transaction is complete.
Signed-off-by: Todd Kjos <tk...@google.com>
---
drivers/android/binder.c | 22 +++++++++++++++++-----
1 file changed, 17 insertions(+), 5 deletions(-)
diff --git a/drivers/android/binder.c b/drivers/android/binder.c
index 84a57dd7b973..fb79f40111eb 100644
--- a/drivers/android/binder.c
+++ b/drivers/android/binder.c
@@ -1469,8 +1469,19 @@ static void binder_transaction(struct binder_proc *proc,
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.
+ */
ref = binder_get_ref(proc, tr->target.handle, true);
- if (ref == NULL) {
+ if (ref) {
+ binder_inc_node(ref->node, 1, 0, NULL);
+ target_node = ref->node;
+ }
+ if (target_node == NULL) {
binder_user_error("%d:%d got transaction to
invalid handle\n",
proc->pid, thread->pid);
return_error = BR_FAILED_REPLY;
@@ -1478,7 +1489,6 @@ static void binder_transaction(struct binder_proc *proc,
return_error_line = __LINE__;
goto err_invalid_target_handle;
}
- target_node = ref->node;
} else {
mutex_lock(&context->context_mgr_node_lock);
target_node = context->binder_context_mgr_node;
@@ -1488,6 +1498,7 @@ static void binder_transaction(struct binder_proc *proc,
return_error_line = __LINE__;
goto err_no_context_mgr_node;
}
+ binder_inc_node(target_node, 1, 0, NULL);
mutex_unlock(&context->context_mgr_node_lock);
}
e->to_node = target_node->debug_id;
@@ -1608,9 +1619,6 @@ static void binder_transaction(struct binder_proc *proc,
t->buffer->transaction = t;
t->buffer->target_node = target_node;
trace_binder_transaction_alloc_buf(t->buffer);
- if (target_node)
- binder_inc_node(target_node, 1, 0, NULL);
-
off_start = (binder_size_t *)(t->buffer->data +
ALIGN(tr->data_size, sizeof(void *)));
offp = off_start;
@@ -1846,6 +1854,7 @@ static void binder_transaction(struct binder_proc *proc,
err_copy_data_failed:
trace_binder_transaction_failed_buffer_release(t->buffer);
binder_transaction_buffer_release(target_proc, t->buffer, offp);
+ target_node = NULL;
t->buffer->transaction = NULL;
binder_alloc_free_buf(&target_proc->alloc, t->buffer);
err_binder_alloc_buf_failed:
@@ -1860,6 +1869,9 @@ static void binder_transaction(struct binder_proc *proc,
err_dead_binder:
err_invalid_target_handle:
err_no_context_mgr_node:
+ if (target_node)
+ binder_dec_node(target_node, 1, 0);
+
binder_debug(BINDER_DEBUG_FAILED_TRANSACTION,
"%d:%d transaction failed %d/%d, size %lld-%lld line %d\n",
proc->pid, thread->pid, return_error, return_error_param,
--
2.13.2.725.g09c95d1e9-goog
