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
There are also handy shell scripts to test CPU and memory hotplug notifier.
Note that these tests didn't detect error handling bugs on my machine but
I still think this feature is usefull to test the code path which is rarely
executed.
Changelog:
* 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 notifier error injection testing scripts
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/fault-injection/cpu-notifier.sh | 169 +++++++++++++++++++++
tools/testing/fault-injection/memory-notifier.sh | 176 ++++++++++++++++++++++
10 files changed, 748 insertions(+), 40 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 100755 tools/testing/fault-injection/cpu-notifier.sh
create mode 100755 tools/testing/fault-injection/memory-notifier.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>
--
1.7.10.2
