This provides kernel modules that can be used to test the error handling of notifier call chain failures by injecting artifical errors to the following notifier chain callbacks. * CPU notifier * PM notifier * memory hotplug notifier * powerpc pSeries reconfig notifier Example: Inject CPU offline error (-1 == -EPERM) # cd /sys/kernel/debug/notifier-error-inject/cpu # echo -1 > actions/CPU_DOWN_PREPARE/error # echo 0 > /sys/devices/system/cpu/cpu1/online bash: echo: write error: Operation not permitted This also adds cpu and memory hotplug tests to tools/testing/selftests These tests first do simple online and offline test and then do fault injection tests if notifier error injection module is available. Changelog: * v5 (change only testing scripts) - make testing scripts a part of tools/testing/selftests - do simple on/offline tests even if no notifier error injection support * v4 (It is about 11 months since v3) - prefix all APIs with notifier_err_inject_* - rearrange debugfs interface (e.g. $DEBUGFS/cpu-notifier-error-inject/CPU_DOWN_PREPARE --> $DEBUGFS/notifier-error-inject/cpu/actions/CPU_DOWN_PREPARE/error) - update modules to follow new interface - add -r option for memory-notifier.sh to specify percent of offlining memory blocks * v3 - rewrite to be kernel modules instead of initializing at late_initcall()s (it makes the diffstat look different but most code remains unchanged) - export err_inject_notifier_block_{init,cleanup} for modules - export pSeries_reconfig_notifier_{,un}register symbols for a module - notifier priority can be specified as a module parameter - add testing scripts in tools/testing/fault-injection * v2 - "PM: Improve error code of pm_notifier_call_chain()" is now in -next - "debugfs: add debugfs_create_int" is dropped - put a comment in err_inject_notifier_block_init() - only allow valid errno to be injected (-MAX_ERRNO <= errno <= 0) - improve Kconfig help text - make CONFIG_PM_NOTIFIER_ERROR_INJECTION visible even if PM_DEBUG is disabled - make CONFIG_PM_NOTIFIER_ERROR_INJECTION default if PM_DEBUG is enabled Akinobu Mita (6): fault-injection: notifier error injection cpu: rewrite cpu-notifier-error-inject module PM: PM notifier error injection module memory: memory notifier error injection module powerpc: pSeries reconfig notifier error injection module fault-injection: add selftests for cpu and memory hotplug lib/Kconfig.debug | 91 +++++++- lib/Makefile | 5 + lib/cpu-notifier-error-inject.c | 63 +++--- lib/memory-notifier-error-inject.c | 48 ++++ lib/notifier-error-inject.c | 112 ++++++++++ lib/notifier-error-inject.h | 24 ++ lib/pSeries-reconfig-notifier-error-inject.c | 51 +++++ lib/pm-notifier-error-inject.c | 49 +++++ tools/testing/selftests/Makefile | 2 +- tools/testing/selftests/cpu-hotplug/Makefile | 6 + tools/testing/selftests/cpu-hotplug/on-off-test.sh | 221 +++++++++++++++++++ tools/testing/selftests/memory-hotplug/Makefile | 6 + .../selftests/memory-hotplug/on-off-test.sh | 230 ++++++++++++++++++++ 13 files changed, 867 insertions(+), 41 deletions(-) create mode 100644 lib/memory-notifier-error-inject.c create mode 100644 lib/notifier-error-inject.c create mode 100644 lib/notifier-error-inject.h create mode 100644 lib/pSeries-reconfig-notifier-error-inject.c create mode 100644 lib/pm-notifier-error-inject.c create mode 100644 tools/testing/selftests/cpu-hotplug/Makefile create mode 100755 tools/testing/selftests/cpu-hotplug/on-off-test.sh create mode 100644 tools/testing/selftests/memory-hotplug/Makefile create mode 100755 tools/testing/selftests/memory-hotplug/on-off-test.sh Cc: Pavel Machek <pavel@xxxxxx> Cc: "Rafael J. Wysocki" <rjw@xxxxxxx> Cc: linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx Cc: Greg KH <greg@xxxxxxxxx> Cc: linux-mm@xxxxxxxxx Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx> Cc: Paul Mackerras <paulus@xxxxxxxxx> Cc: linuxppc-dev@xxxxxxxxxxxxxxxx Cc: Américo Wang <xiyou.wangcong@xxxxxxxxx> Cc: Michael Ellerman <michael@xxxxxxxxxxxxxx> Cc: Dave Jones <davej@xxxxxxxxxx> -- 1.7.10.4