Merge "Add group ID for reading tracefs"

libcutils/include/private/android_filesystem_config.h

@@ -158,6 +158,7 @@
 #define AID_READPROC 3009     /* Allow /proc read access */
 #define AID_WAKELOCK 3010     /* Allow system wakelock read/write access */
 #define AID_UHID 3011         /* Allow read/write to /dev/uhid node */
+#define AID_READTRACEFS 3012  /* Allow tracefs read */
 
 /* The range 5000-5999 is also reserved for vendor partition. */
 #define AID_OEM_RESERVED_2_START 5000

rootdir/init.rc

@@ -78,8 +78,8 @@ on early-init
     mkdir /dev/boringssl 0755 root root
     mkdir /dev/boringssl/selftest 0755 root root
 
-    # Mount tracefs
-    mount tracefs tracefs /sys/kernel/tracing
+    # Mount tracefs (with GID=AID_READTRACEFS)
+    mount tracefs tracefs /sys/kernel/tracing gid=3012
 
     # create sys dirctory
     mkdir /dev/sys 0755 system system