diff options
| author | Todd Kjos <tkjos@android.com> | 2017-06-29 12:01:56 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-07-17 14:47:30 +0200 |
| commit | eb34983ba170f236b6801c7bee717da6abe4aff0 (patch) | |
| tree | 4517f9556de660dc76db9bf452895318e7adb4d7 | |
| parent | 26549d17741035b604048770f354c8c6b5e25ac9 (diff) | |
binder: make sure target_node has strong ref
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 <tkjos@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/android/binder.c | 22 |
1 files 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 @@ err_bad_parent: 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 @@ err_empty_call_stack: 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, |