# lmkd low memory killer daemon type lmkd, domain, mlstrustedsubject; type lmkd_exec, exec_type, file_type; allow lmkd self:global_capability_class_set { dac_override dac_read_search sys_resource kill }; # lmkd locks itself in memory, to prevent it from being # swapped out and unable to kill other memory hogs. # system/core commit b28ff9131363f7b4a698990da5748b2a88c3ed35 # b/16236289 allow lmkd self:global_capability_class_set ipc_lock; ## Open and write to /proc/PID/oom_score_adj ## TODO: maybe scope this down? r_dir_file(lmkd, appdomain) allow lmkd appdomain:file write; r_dir_file(lmkd, system_server) allow lmkd system_server:file write; ## Writes to /sys/module/lowmemorykiller/parameters/minfree r_dir_file(lmkd, sysfs_lowmemorykiller) allow lmkd sysfs_lowmemorykiller:file w_file_perms; # Send kill signals allow lmkd appdomain:process sigkill; # Clean up old cgroups allow lmkd cgroup:dir { remove_name rmdir }; # Allow to read memcg stats allow lmkd cgroup:file r_file_perms; # Set self to SCHED_FIFO allow lmkd self:global_capability_class_set sys_nice; allow lmkd proc_zoneinfo:file r_file_perms; # Set sys.lmk.* properties. set_prop(lmkd, system_lmk_prop) # live lock watchdog process allowed to look through /proc/ allow lmkd domain:dir { search open read }; allow lmkd domain:file { open read }; # live lock watchdog process allowed to dump process trace and # reboot because orderly shutdown may not be possible. allow lmkd proc_sysrq:file rw_file_perms; # Read /proc/meminfo allow lmkd proc_meminfo:file r_file_perms; ### neverallow rules # never honor LD_PRELOAD neverallow * lmkd:process noatsecure;