Label /dev/dma_heap/* char devices with dma_device_t

In the /dev/dma_heap directory, character devices are created to
allow userspace to allocate dma buffers that can be shared between drivers.

The change is backed by a file transition for the "system" file;
note the /dev/dma_heap directory keeps the default device_t type
so the transition will apply for a "system" file anywhere in /dev.

A new dma_device_t type was added.

Resolves: rhbz#1970744

policy/modules/kernel/devices.fc

@@ -24,6 +24,7 @@
 /dev/crash		-c	gen_context(system_u:object_r:crash_device_t,mls_systemhigh)
 /dev/dahdi/.*		-c	gen_context(system_u:object_r:sound_device_t,s0)
 /dev/dlm.*		-c	gen_context(system_u:object_r:dlm_control_device_t,s0)
+/dev/dma_heap/.+	-c	gen_context(system_u:object_r:dma_device_t,s0)
 /dev/dmfm.*		-c	gen_context(system_u:object_r:sound_device_t,s0)
 /dev/dmmidi.*		-c	gen_context(system_u:object_r:sound_device_t,s0)
 /dev/drm_dp_aux.*		-c	gen_context(system_u:object_r:xserver_misc_device_t,s0)

policy/modules/kernel/devices.if

@@ -6556,6 +6556,7 @@ interface(`dev_filetrans_all_named_dev',`
 gen_require(`
 	type device_t;
 	type acpi_device_t;
+	type dma_device_t;
 	type usb_device_t;
     type uhid_device_t;
 	type sound_device_t;
@@ -6703,6 +6704,8 @@ gen_require(`
 	filetrans_pattern($1, device_t, dlm_control_device_t, chr_file, "dlm7")
 	filetrans_pattern($1, device_t, dlm_control_device_t, chr_file, "dlm8")
 	filetrans_pattern($1, device_t, dlm_control_device_t, chr_file, "dlm9")
+	# Note this file path is /dev/dma_heap/system
+	filetrans_pattern($1, device_t, dma_device_t, chr_file, "system")
 	filetrans_pattern($1, device_t, sound_device_t, chr_file, "dmfm")
 	filetrans_pattern($1, device_t, sound_device_t, chr_file, "dmmidi0")
 	filetrans_pattern($1, device_t, sound_device_t, chr_file, "dmmidi1")

policy/modules/kernel/devices.te

@@ -88,6 +88,12 @@ dev_node(crypt_device_t)
 type dlm_control_device_t;
 dev_node(dlm_control_device_t)
 
+#
+# Type for /dev/dma_heap/* devices
+#
+type dma_device_t;
+dev_node(dma_device_t)
+
 type dri_device_t;
 dev_node(dri_device_t)