kernel: re-implement sending handles via port messages

syscall/msg.c

@@ -161,17 +161,17 @@ kern_status_t sys_port_disconnect(kern_handle_t port_handle)
 
 static bool validate_iovec(
 	struct task *task,
-	const struct iovec *iov,
+	const kern_iovec_t *iov,
 	size_t count,
 	bool rw)
 {
-	if (!validate_access_r(task, iov, count * sizeof(struct iovec))) {
+	if (!validate_access_r(task, iov, count * sizeof(*iov))) {
 		return false;
 	}
 
 	for (size_t i = 0; i < count; i++) {
 		bool ok = false;
-		const struct iovec *vec = &iov[i];
+		const kern_iovec_t *vec = &iov[i];
 		if (rw) {
 			ok = validate_access_w(task, vec->io_base, vec->io_len);
 		} else {
@@ -186,23 +186,55 @@ static bool validate_iovec(
 	return true;
 }
 
-kern_status_t sys_msg_send(
-	kern_handle_t port_handle,
-	const struct iovec *req_data,
-	size_t req_data_count,
-	struct iovec *resp_data,
-	size_t resp_data_count)
+static bool validate_msg(struct task *task, const kern_msg_t *msg, bool rw)
 {
-	struct task *self = current_task();
-
-	if (!validate_iovec(self, req_data, req_data_count, false)) {
+	if (!msg) {
 		return false;
 	}
 
-	if (!validate_iovec(self, resp_data, resp_data_count, true)) {
+	vm_prot_t flags;
+	if (rw) {
+		flags = VM_PROT_WRITE | VM_PROT_USER;
+	} else {
+		flags = VM_PROT_READ | VM_PROT_USER;
+	}
+
+	if (!validate_access(task, msg, sizeof *msg, flags)) {
 		return false;
 	}
 
+	if (!validate_iovec(task, msg->msg_data, msg->msg_data_count, rw)) {
+		return false;
+	}
+
+	size_t handle_buffer_len
+		= msg->msg_handles_count * sizeof(*msg->msg_handles);
+	if (!validate_access(
+		    task,
+		    msg->msg_handles,
+		    handle_buffer_len,
+		    flags)) {
+		return false;
+	}
+
+	return true;
+}
+
+kern_status_t sys_msg_send(
+	kern_handle_t port_handle,
+	const kern_msg_t *msg,
+	kern_msg_t *out_reply)
+{
+	struct task *self = current_task();
+
+	if (!validate_msg(self, msg, false)) {
+		return KERN_MEMORY_FAULT;
+	}
+
+	if (!validate_msg(self, out_reply, true)) {
+		return KERN_MEMORY_FAULT;
+	}
+
 	unsigned long flags;
 
 	task_lock_irqsave(self, &flags);
@@ -230,32 +262,18 @@ kern_status_t sys_msg_send(
 	}
 
 	port_lock_irqsave(port, &flags);
-	status = port_send_msg(
-		port,
-		req_data,
-		req_data_count,
-		resp_data,
-		resp_data_count,
-		&flags);
+	status = port_send_msg(port, msg, out_reply, &flags);
 	port_unlock_irqrestore(port, flags);
 	object_unref(port_obj);
 
 	return status;
 }
 
-kern_status_t sys_msg_recv(
-	kern_handle_t channel_handle,
-	msgid_t *out_id,
-	struct iovec *out_data,
-	size_t out_data_count)
+kern_status_t sys_msg_recv(kern_handle_t channel_handle, kern_msg_t *out_msg)
 {
 	struct task *self = current_task();
 
-	if (!validate_access_w(self, out_id, sizeof *out_id)) {
-		return KERN_MEMORY_FAULT;
-	}
-
-	if (!validate_iovec(self, out_data, out_data_count, true)) {
+	if (!validate_msg(self, out_msg, true)) {
 		return KERN_MEMORY_FAULT;
 	}
 
@@ -286,12 +304,7 @@ kern_status_t sys_msg_recv(
 	}
 
 	channel_lock_irqsave(channel, &flags);
-	status = channel_recv_msg(
-		channel,
-		out_id,
-		out_data,
-		out_data_count,
-		&flags);
+	status = channel_recv_msg(channel, out_msg, &flags);
 	channel_unlock_irqrestore(channel, flags);
 	object_unref(channel_obj);
 
@@ -301,12 +314,11 @@ kern_status_t sys_msg_recv(
 kern_status_t sys_msg_reply(
 	kern_handle_t channel_handle,
 	msgid_t id,
-	const struct iovec *reply_data,
-	size_t reply_data_count)
+	const kern_msg_t *reply)
 {
 	struct task *self = current_task();
 
-	if (!validate_iovec(self, reply_data, reply_data_count, false)) {
+	if (!validate_msg(self, reply, true)) {
 		return KERN_MEMORY_FAULT;
 	}
 
@@ -337,12 +349,7 @@ kern_status_t sys_msg_reply(
 	}
 
 	channel_lock_irqsave(channel, &flags);
-	status = channel_reply_msg(
-		channel,
-		id,
-		reply_data,
-		reply_data_count,
-		&flags);
+	status = channel_reply_msg(channel, id, reply, &flags);
 	channel_unlock_irqrestore(channel, flags);
 	object_unref(channel_obj);
 
@@ -353,7 +360,7 @@ kern_status_t sys_msg_read(
 	kern_handle_t channel_handle,
 	msgid_t id,
 	size_t offset,
-	const struct iovec *iov,
+	const kern_iovec_t *iov,
 	size_t iov_count,
 	size_t *nr_read)
 {
@@ -412,7 +419,7 @@ kern_status_t sys_msg_write(
 	kern_handle_t channel_handle,
 	msgid_t id,
 	size_t offset,
-	const struct iovec *iov,
+	const kern_iovec_t *iov,
 	size_t iov_count,
 	size_t *nr_written)
 {