Give /proc/iomem a more specific label.

/proc/iomem is currently given the proc label but contains system information
which should not be available to all processes.

Bug: 22008387
Change-Id: I4f1821f40113a743ad986d13d8d130ed8b8abf2f

file.te

@@ -11,6 +11,7 @@ type usermodehelper, fs_type, sysfs_type;
 type qtaguid_proc, fs_type, mlstrustedobject;
 type proc_bluetooth_writable, fs_type;
 type proc_cpuinfo, fs_type;
+type proc_iomem, fs_type;
 type proc_net, fs_type;
 type proc_sysrq, fs_type;
 type selinuxfs, fs_type, mlstrustedobject;

genfs_contexts

@@ -2,6 +2,7 @@
 genfscon rootfs / u:object_r:rootfs:s0
 # proc labeling can be further refined (longest matching prefix).
 genfscon proc / u:object_r:proc:s0
+genfscon proc /iomem u:object_r:proc_iomem:s0
 genfscon proc /net u:object_r:proc_net:s0
 genfscon proc /net/xt_qtaguid/ctrl u:object_r:qtaguid_proc:s0
 genfscon proc /cpuinfo u:object_r:proc_cpuinfo:s0