Fault injection uses debugfs in a way that the provided values via sysfs are interpreted as u64. Providing negative numbers results in an error: # cd sys/kernel/debug/notifier-error-inject/memory # echo -12 > actions/MEM_GOING_ONLINE/error -bash: echo: write error: Invalid argument Update the docs and examples to use "printf %#x <val>" in these cases. Signed-off-by: Zhao Gongyi <zhaogongyi@xxxxxxxxxx> --- .../fault-injection/notifier-error-inject.rst | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/Documentation/fault-injection/notifier-error-inject.rst b/Documentation/fault-injection/notifier-error-inject.rst index 1668b6e48d3a..0e2790122166 100644 --- a/Documentation/fault-injection/notifier-error-inject.rst +++ b/Documentation/fault-injection/notifier-error-inject.rst @@ -11,6 +11,10 @@ modules that can be used to test the following notifiers. * powerpc pSeries reconfig notifier * Netdevice notifier +Note that the interface only accepts unsigned values. So, if you want +to use a negative errno, you'd better use 'printf' instead of 'echo', e.g.: +$ printf %#x -12 > actions/PM_SUSPEND_PREPARE/error + PM notifier error injection module ---------------------------------- This feature is controlled through debugfs interface @@ -26,7 +30,7 @@ Possible PM notifier events to be failed are: Example: Inject PM suspend error (-12 = -ENOMEM):: # cd /sys/kernel/debug/notifier-error-inject/pm/ - # echo -12 > actions/PM_SUSPEND_PREPARE/error + # printf %#x -12 > actions/PM_SUSPEND_PREPARE/error # echo mem > /sys/power/state bash: echo: write error: Cannot allocate memory @@ -44,7 +48,7 @@ Possible memory notifier events to be failed are: Example: Inject memory hotplug offline error (-12 == -ENOMEM):: # cd /sys/kernel/debug/notifier-error-inject/memory - # echo -12 > actions/MEM_GOING_OFFLINE/error + # printf %#x -12 > actions/MEM_GOING_OFFLINE/error # echo offline > /sys/devices/system/memory/memoryXXX/state bash: echo: write error: Cannot allocate memory @@ -82,7 +86,7 @@ Netdevice notifier events which can be failed are: Example: Inject netdevice mtu change error (-22 == -EINVAL):: # cd /sys/kernel/debug/notifier-error-inject/netdev - # echo -22 > actions/NETDEV_CHANGEMTU/error + # printf %#x -22 > actions/NETDEV_CHANGEMTU/error # ip link set eth0 mtu 1024 RTNETLINK answers: Invalid argument -- 2.17.1
