Merge "mink: Race condition for local object processing" (79df7547) · Commits · e / devices / android_kernel_fairphone_FP4

drivers/soc/qcom/smcinvoke.c

+55 −36

Original line number	Diff line number	Diff line
		@@ -398,10 +398,10 @@ static void free_pending_cbobj_locked(struct kref *kref)

		static int get_pending_cbobj_locked(uint16_t srvr_id, int16_t obj_id)
		{
		struct smcinvoke_server_info *server = find_cb_server_locked(srvr_id);
		struct list_head *head = NULL;
		struct smcinvoke_cbobj *cbobj = NULL;
		struct smcinvoke_cbobj *obj = NULL;
		struct smcinvoke_server_info *server = find_cb_server_locked(srvr_id);

		if (!server)
		return OBJECT_ERROR_BADOBJ;
		@@ -469,7 +469,11 @@ static void delete_cb_txn(struct kref *kref)
		struct smcinvoke_cb_txn *cb_txn = container_of(kref,
		struct smcinvoke_cb_txn, ref_cnt);

		if (OBJECT_OP_METHODID(cb_txn->cb_req->hdr.op) == OBJECT_OP_RELEASE)
		release_tzhandle_locked(cb_txn->cb_req->hdr.tzhandle);

		kfree(cb_txn->cb_req);
		hash_del(&cb_txn->hash);
		kfree(cb_txn);
		}

		@@ -846,19 +850,13 @@ static void process_tzcb_req(void buf, size_t buf_len, struct file *arr_filp)
		/* ret is going to TZ. Provide values from OBJECT_ERROR_<> */
		int ret = OBJECT_ERROR_DEFUNCT;
		struct smcinvoke_cb_txn *cb_txn = NULL;
		struct smcinvoke_tzcb_req *cb_req = NULL;
		struct smcinvoke_tzcb_req cb_req = NULL, tmp_cb_req = NULL;
		struct smcinvoke_server_info *srvr_info = NULL;

		if (buf_len < sizeof(struct smcinvoke_tzcb_req))
		return;

		cb_req = kmemdup(buf, buf_len, GFP_KERNEL);
		if (!cb_req) {
		/* we need to return error to caller so fill up result */
		cb_req = buf;
		cb_req->result = OBJECT_ERROR_KMEM;
		return;
		}

		/* check whether it is to be served by kernel or userspace */
		if (TZHANDLE_IS_KERNEL_OBJ(cb_req->hdr.tzhandle)) {
		@@ -870,11 +868,26 @@ static void process_tzcb_req(void buf, size_t buf_len, struct file *arr_filp)
		return;
		}

		/*
		* We need a copy of req that could be sent to server. Otherwise, if
		* someone kills invoke caller, buf would go away and server would be
		* working on already freed buffer, causing a device crash.
		*/
		tmp_cb_req = kmemdup(buf, buf_len, GFP_KERNEL);
		if (!tmp_cb_req) {
		/* we need to return error to caller so fill up result */
		cb_req->result = OBJECT_ERROR_KMEM;
		return;
		}

		cb_txn = kzalloc(sizeof(*cb_txn), GFP_KERNEL);
		if (!cb_txn) {
		ret = OBJECT_ERROR_KMEM;
		goto out;
		cb_req->result = OBJECT_ERROR_KMEM;
		kfree(tmp_cb_req);
		return;
		}
		/* no need for memcpy as we did kmemdup() above */
		cb_req = tmp_cb_req;

		cb_txn->state = SMCINVOKE_REQ_PLACED;
		cb_txn->cb_req = cb_req;
		@@ -886,6 +899,7 @@ static void process_tzcb_req(void buf, size_t buf_len, struct file *arr_filp)
		srvr_info = find_cb_server_locked(
		TZHANDLE_GET_SERVER(cb_req->hdr.tzhandle));
		if (!srvr_info \|\| srvr_info->state == SMCINVOKE_SERVER_STATE_DEFUNCT) {
		/* ret equals Object_ERROR_DEFUNCT, at this point go to out */
		mutex_unlock(&g_smcinvoke_lock);
		goto out;
		}
		@@ -893,33 +907,36 @@ static void process_tzcb_req(void buf, size_t buf_len, struct file *arr_filp)
		cb_txn->txn_id = ++srvr_info->txn_id;
		hash_add(srvr_info->reqs_table, &cb_txn->hash, cb_txn->txn_id);
		mutex_unlock(&g_smcinvoke_lock);
		/*
		* we need not worry that server_info will be deleted because as long
		* as this CBObj is served by this server, srvr_info will be valid.
		*/
		wake_up_interruptible(&srvr_info->req_wait_q);
		ret = wait_event_interruptible(srvr_info->rsp_wait_q,
		(cb_txn->state == SMCINVOKE_REQ_PROCESSED) \|\|
		(srvr_info->state == SMCINVOKE_SERVER_STATE_DEFUNCT));
		if (ret)
		pr_err("%s wait_event interrupted: ret = %d\n", __func__, ret);
		out:
		/*
		* If we are here, either req is processed or not
		* if processed, result would have been set by txn processor
		* if not processed, we should set result with ret which should have
		* correct value that TZ/TA can understand
		* we could be here because of either: a. Req is PROCESSED
		* b. Server was killed c. Invoke thread is killed
		* sometime invoke thread and server are part of same process.
		*/
		mutex_lock(&g_smcinvoke_lock);
		if (!cb_txn \|\| (cb_txn->state != SMCINVOKE_REQ_PROCESSED)) {
		cb_req->result = ret;
		if (srvr_info &&
		srvr_info->state == SMCINVOKE_SERVER_STATE_DEFUNCT &&
		OBJECT_OP_METHODID(cb_req->hdr.op) == OBJECT_OP_RELEASE) {
		release_tzhandle_locked(cb_req->hdr.tzhandle);
		}
		}
		if (cb_txn) {
		hash_del(&cb_txn->hash);
		if (cb_txn->state == SMCINVOKE_REQ_PROCESSED) {
		/*
		* it is possible that server was killed immediately
		* after CB Req was processed but who cares now!
		*/
		} else if (!srvr_info \|\|
		srvr_info->state == SMCINVOKE_SERVER_STATE_DEFUNCT) {
		cb_req->result = OBJECT_ERROR_DEFUNCT;
		} else {
		pr_debug("%s wait_event interrupted ret = %d\n", __func__, ret);
		cb_req->result = OBJECT_ERROR_ABORT;
		}
		memcpy(buf, cb_req, buf_len);
		kref_put(&cb_txn->ref_cnt, delete_cb_txn);
		}
		mutex_unlock(&g_smcinvoke_lock);
		}

		@@ -1447,24 +1464,26 @@ static long process_accept_req(struct file *filp, unsigned int cmd,
		cb_txn = find_cbtxn_locked(server_info, user_args.txn_id,
		SMCINVOKE_REQ_PROCESSING);
		mutex_unlock(&g_smcinvoke_lock);
		/* cb_txn can be null if userspace provides wrong txn id. */
		/*
		* cb_txn can be null if userspace provides wrong txn id OR
		* invoke thread died while server was processing cb req.
		* if invoke thread dies, it would remove req from Q. So
		* no matching cb_txn would be on Q and hence NULL cb_txn.
		*/
		if (!cb_txn) {
		pr_err("%s: Invalid txn received = %d\n",
		pr_err("%s txn %d either invalid or removed from Q\n",
		__func__, user_args.txn_id);
		goto out;
		}
		ret = marshal_out_tzcb_req(&user_args, cb_txn,
		cb_txn->filp_to_release);
		/*
		* if client did not set error and we get error locally
		* if client did not set error and we get error locally,
		* we return local error to TA
		*/
		if (ret && cb_txn->cb_req->result == 0)
		cb_txn->cb_req->result = OBJECT_ERROR_UNAVAIL;

		if (OBJECT_OP_METHODID(user_args.op) == OBJECT_OP_RELEASE)
		release_tzhandles(&cb_txn->cb_req->hdr.tzhandle, 1);

		cb_txn->state = SMCINVOKE_REQ_PROCESSED;
		kref_put(&cb_txn->ref_cnt, delete_cb_txn);
		wake_up(&server_info->rsp_wait_q);
		@@ -1483,7 +1502,7 @@ static long process_accept_req(struct file *filp, unsigned int cmd,
		ret = wait_event_interruptible(server_info->req_wait_q,
		!hash_empty(server_info->reqs_table));
		if (ret) {
		pr_err("%s wait_event interrupted: ret = %d\n",
		pr_debug("%s wait_event interrupted: ret = %d\n",
		__func__, ret);
		goto out;
		}