1# lmkd low memory killer daemon 2type lmkd, domain, mlstrustedsubject; 3type lmkd_exec, system_file_type, exec_type, file_type; 4 5allow lmkd self:global_capability_class_set { dac_override dac_read_search sys_resource kill }; 6 7# lmkd locks itself in memory, to prevent it from being 8# swapped out and unable to kill other memory hogs. 9# system/core commit b28ff9131363f7b4a698990da5748b2a88c3ed35 10# b/16236289 11allow lmkd self:global_capability_class_set ipc_lock; 12 13## Open and write to /proc/PID/oom_score_adj 14## TODO: maybe scope this down? 15r_dir_file(lmkd, appdomain) 16allow lmkd appdomain:file write; 17r_dir_file(lmkd, system_server) 18allow lmkd system_server:file write; 19 20## Writes to /sys/module/lowmemorykiller/parameters/minfree 21r_dir_file(lmkd, sysfs_lowmemorykiller) 22allow lmkd sysfs_lowmemorykiller:file w_file_perms; 23 24# setsched and send kill signals 25allow lmkd appdomain:process { setsched sigkill }; 26allow lmkd kernel:process { setsched }; 27 28# Clean up old cgroups 29allow lmkd cgroup:dir { remove_name rmdir }; 30 31# Allow to read memcg stats 32allow lmkd cgroup:file r_file_perms; 33 34# Set self to SCHED_FIFO 35allow lmkd self:global_capability_class_set sys_nice; 36 37allow lmkd proc_zoneinfo:file r_file_perms; 38 39# Set sys.lmk.* properties. 40set_prop(lmkd, system_lmk_prop) 41 42# live lock watchdog process allowed to look through /proc/ 43allow lmkd domain:dir { search open read }; 44allow lmkd domain:file { open read }; 45 46# live lock watchdog process allowed to dump process trace and 47# reboot because orderly shutdown may not be possible. 48allow lmkd proc_sysrq:file rw_file_perms; 49 50# Read /proc/meminfo 51allow lmkd proc_meminfo:file r_file_perms; 52 53# Read /proc/pressure/cpu and /proc/pressure/io 54allow lmkd proc_pressure_cpu:file r_file_perms; 55allow lmkd proc_pressure_io:file r_file_perms; 56 57# Read/Write /proc/pressure/memory 58allow lmkd proc_pressure_mem:file rw_file_perms; 59 60# Allow lmkd to write to statsd. 61unix_socket_send(lmkd, statsdw, statsd) 62 63### neverallow rules 64 65# never honor LD_PRELOAD 66neverallow * lmkd:process noatsecure; 67