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