Label /proc/meminfo.

Address the following denial:
m.chrome.canary: type=1400 audit(0.0:15): avc: granted { read open } for path="/proc/meminfo" dev="proc" ino=4026544360 scontext=u:r:untrusted_app:s0:c512,c768 tcontext=u:object_r:proc:s0 tclass=file

Bug: 22032619
Chromium Bug: 586021

Change-Id: I584345c84d870c313da69ec97a0b1e54c0eb9ee1

domain_deprecated.te

@@ -57,6 +57,7 @@ r_dir_file(domain_deprecated, proc)
 r_dir_file(domain_deprecated, sysfs)
 r_dir_file(domain_deprecated, inotify)
 r_dir_file(domain_deprecated, cgroup)
+r_dir_file(domain_deprecated, proc_meminfo)
 r_dir_file(domain_deprecated, proc_net)
 
 # Get SELinux enforcing status.

file.te

@@ -14,6 +14,7 @@ type qtaguid_proc, fs_type, mlstrustedobject;
 type proc_bluetooth_writable, fs_type;
 type proc_cpuinfo, fs_type;
 type proc_iomem, fs_type;
+type proc_meminfo, fs_type;
 type proc_net, fs_type;
 type proc_sysrq, fs_type;
 type proc_uid_cputime_showstat, fs_type;

genfs_contexts

@@ -3,6 +3,7 @@ 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 /meminfo u:object_r:proc_meminfo: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

untrusted_app.te

@@ -94,10 +94,11 @@ allow untrusted_app self:process ptrace;
 # for files. Suppress the denials when they occur.
 dontaudit untrusted_app exec_type:file getattr;
 
-# TODO: access of /proc/meminfo, give specific label or switch to
-# using meminfo service
-allow untrusted_app proc:file r_file_perms;
+# TODO: switch to meminfo service
+allow untrusted_app proc_meminfo:file r_file_perms;
+
 # https://code.google.com/p/chromium/issues/detail?id=586021
+allow untrusted_app proc:file r_file_perms;
 auditallow untrusted_app proc:file r_file_perms;
 # access /proc/net/xt_qtguid/stats
 r_dir_file(untrusted_app, proc_net)