android_system_sepolicy/public/bootstat.te

# bootstat command
type bootstat, domain;
type bootstat_exec, system_file_type, exec_type, file_type;

read_runtime_log_tags(bootstat)

# Allow persistent storage in /data/misc/bootstat.
allow bootstat bootstat_data_file:dir rw_dir_perms;
allow bootstat bootstat_data_file:file create_file_perms;

# Collect metrics on boot time created by init
get_prop(bootstat, boottime_prop)

# Read/Write [persist.]sys.boot.reason and ro.boot.bootreason (write if empty)
set_prop(bootstat, bootloader_boot_reason_prop)
set_prop(bootstat, system_boot_reason_prop)
set_prop(bootstat, last_boot_reason_prop)

# ToDo: TBI move access for the following to a system health HAL

# Allow access to /sys/fs/pstore/ and syslog
allow bootstat pstorefs:dir search;
allow bootstat pstorefs:file r_file_perms;
allow bootstat kernel:system syslog_read;

# Allow access to reading the logs to read aspects of system health
read_logd(bootstat)

# Allow bootstat write to statsd.
unix_socket_send(bootstat, statsdw, statsd)

# ToDo: end

neverallow {
  domain
  -bootanim
  -bootstat
  -dumpstate
  -init
  -recovery
  -shell
  -system_server
} { bootloader_boot_reason_prop last_boot_reason_prop }:file r_file_perms;
# ... and refine, as these components should not set the last boot reason
neverallow { bootanim recovery } last_boot_reason_prop:file r_file_perms;

neverallow {
  domain
  -bootstat
  -init
  -system_server
} { bootloader_boot_reason_prop last_boot_reason_prop }:property_service set;
# ... and refine ... for a ro propertly no less ... keep this _tight_
neverallow system_server bootloader_boot_reason_prop:property_service set;

neverallow {
  domain
  -bootstat
  -init
} system_boot_reason_prop:property_service set;