Orange Pi5 kernel

^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  1) Notifier error injection
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  2) ========================
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  3) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  4) Notifier error injection provides the ability to inject artificial errors to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  5) specified notifier chain callbacks. It is useful to test the error handling of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  6) notifier call chain failures which is rarely executed.  There are kernel
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  7) modules that can be used to test the following notifiers.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  8) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  9)  * PM notifier
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10)  * Memory hotplug notifier
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11)  * powerpc pSeries reconfig notifier
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12)  * Netdevice notifier
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) PM notifier error injection module
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) ----------------------------------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) This feature is controlled through debugfs interface
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18)   /sys/kernel/debug/notifier-error-inject/pm/actions/<notifier event>/error
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) Possible PM notifier events to be failed are:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22)  * PM_HIBERNATION_PREPARE
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23)  * PM_SUSPEND_PREPARE
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24)  * PM_RESTORE_PREPARE
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) Example: Inject PM suspend error (-12 = -ENOMEM)::
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) 	# cd /sys/kernel/debug/notifier-error-inject/pm/
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) 	# echo -12 > actions/PM_SUSPEND_PREPARE/error
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) 	# echo mem > /sys/power/state
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) 	bash: echo: write error: Cannot allocate memory
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) Memory hotplug notifier error injection module
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) ----------------------------------------------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) This feature is controlled through debugfs interface
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37)   /sys/kernel/debug/notifier-error-inject/memory/actions/<notifier event>/error
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) Possible memory notifier events to be failed are:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41)  * MEM_GOING_ONLINE
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42)  * MEM_GOING_OFFLINE
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) Example: Inject memory hotplug offline error (-12 == -ENOMEM)::
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) 	# cd /sys/kernel/debug/notifier-error-inject/memory
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) 	# echo -12 > actions/MEM_GOING_OFFLINE/error
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) 	# echo offline > /sys/devices/system/memory/memoryXXX/state
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) 	bash: echo: write error: Cannot allocate memory
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) powerpc pSeries reconfig notifier error injection module
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) --------------------------------------------------------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) This feature is controlled through debugfs interface
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55)   /sys/kernel/debug/notifier-error-inject/pSeries-reconfig/actions/<notifier event>/error
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) Possible pSeries reconfig notifier events to be failed are:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59)  * PSERIES_RECONFIG_ADD
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60)  * PSERIES_RECONFIG_REMOVE
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61)  * PSERIES_DRCONF_MEM_ADD
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62)  * PSERIES_DRCONF_MEM_REMOVE
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) Netdevice notifier error injection module
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) ----------------------------------------------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) This feature is controlled through debugfs interface
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68)   /sys/kernel/debug/notifier-error-inject/netdev/actions/<notifier event>/error
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) Netdevice notifier events which can be failed are:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72)  * NETDEV_REGISTER
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73)  * NETDEV_CHANGEMTU
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74)  * NETDEV_CHANGENAME
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75)  * NETDEV_PRE_UP
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76)  * NETDEV_PRE_TYPE_CHANGE
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77)  * NETDEV_POST_INIT
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78)  * NETDEV_PRECHANGEMTU
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79)  * NETDEV_PRECHANGEUPPER
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80)  * NETDEV_CHANGEUPPER
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) Example: Inject netdevice mtu change error (-22 == -EINVAL)::
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) 	# cd /sys/kernel/debug/notifier-error-inject/netdev
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) 	# echo -22 > actions/NETDEV_CHANGEMTU/error
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) 	# ip link set eth0 mtu 1024
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) 	RTNETLINK answers: Invalid argument
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) For more usage examples
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) -----------------------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) There are tools/testing/selftests using the notifier error injection features
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92) for CPU and memory notifiers.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94)  * tools/testing/selftests/cpu-hotplug/on-off-test.sh
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95)  * tools/testing/selftests/memory-hotplug/on-off-test.sh
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97) These scripts first do simple online and offline tests and then do fault
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) injection tests if notifier error injection module is available.