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authorAkinobu Mita <akinobu.mita@gmail.com>2012-07-30 14:43:03 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2012-07-30 17:25:22 -0700
commitf5a9f52e2c5654c3d212dbf7e7a169c60876691a (patch)
tree81b8394ed422894cc9606a0d8030c5b52a246a00 /lib/Kconfig.debug
parent8d438288145f19f253a82ca71290b44fce79e23f (diff)
cpu: rewrite cpu-notifier-error-inject module
Rewrite existing cpu-notifier-error-inject module to use debugfs based new framework. This change removes cpu_up_prepare_error and cpu_down_prepare_error module parameters which were used to specify error code to be injected. We could keep these module parameters for backward compatibility by module_param_cb but it seems overkill for this module. This provides the ability to inject artifical errors to CPU notifier chain callbacks. It is controlled through debugfs interface under /sys/kernel/debug/notifier-error-inject/cpu If the notifier call chain should be failed with some events notified, write the error code to "actions/<notifier event>/error". Example1: 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 Example2: inject CPU online error (-2 == -ENOENT) # cd /sys/kernel/debug/notifier-error-inject/cpu # echo -2 > actions/CPU_UP_PREPARE/error # echo 1 > /sys/devices/system/cpu/cpu1/online bash: echo: write error: No such file or directory Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Cc: Greg KH <greg@kroah.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <michael@ellerman.id.au> Cc: Dave Jones <davej@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'lib/Kconfig.debug')
-rw-r--r--lib/Kconfig.debug16
1 files changed, 14 insertions, 2 deletions
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index bdee91d50a5b..20341480bb54 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -1097,10 +1097,22 @@ config NOTIFIER_ERROR_INJECTION
config CPU_NOTIFIER_ERROR_INJECT
tristate "CPU notifier error injection module"
- depends on HOTPLUG_CPU && DEBUG_KERNEL
+ depends on HOTPLUG_CPU && NOTIFIER_ERROR_INJECTION
help
This option provides a kernel module that can be used to test
- the error handling of the cpu notifiers
+ the error handling of the cpu notifiers by injecting artifical
+ errors to CPU notifier chain callbacks. It is controlled through
+ debugfs interface under /sys/kernel/debug/notifier-error-inject/cpu
+
+ If the notifier call chain should be failed with some events
+ notified, write the error code to "actions/<notifier event>/error".
+
+ 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
To compile this code as a module, choose M here: the module will
be called cpu-notifier-error-inject.