The patch titled
Subject: cpu: rewrite cpu-notifier-error-inject module
has been added to the -mm tree. Its filename is
cpu-rewrite-cpu-notifier-error-inject-module.patch
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------------------------------------------------------
From: Akinobu Mita <akinobu.mita@xxxxxxxxx>
Subject: 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@xxxxxxxxx>
Cc: Pavel Machek <pavel@xxxxxx>
Cc: "Rafael J. Wysocki" <rjw@xxxxxxx>
Cc: Greg KH <greg@xxxxxxxxx>
Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
Cc: Paul Mackerras <paulus@xxxxxxxxx>
Cc: Michael Ellerman <michael@xxxxxxxxxxxxxx>
Cc: Dave Jones <davej@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
lib/Kconfig.debug | 16 ++++++-
lib/cpu-notifier-error-inject.c | 63 +++++++++++-------------------
2 files changed, 39 insertions(+), 40 deletions(-)
diff -puN lib/Kconfig.debug~cpu-rewrite-cpu-notifier-error-inject-module lib/Kconfig.debug
--- a/lib/Kconfig.debug~cpu-rewrite-cpu-notifier-error-inject-module
+++ a/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.
diff -puN lib/cpu-notifier-error-inject.c~cpu-rewrite-cpu-notifier-error-inject-module lib/cpu-notifier-error-inject.c
--- a/lib/cpu-notifier-error-inject.c~cpu-rewrite-cpu-notifier-error-inject-module
+++ a/lib/cpu-notifier-error-inject.c
@@ -1,58 +1,45 @@
#include <linux/kernel.h>
-#include <linux/cpu.h>
#include <linux/module.h>
-#include <linux/notifier.h>
+#include <linux/cpu.h>
-static int priority;
-static int cpu_up_prepare_error;
-static int cpu_down_prepare_error;
+#include "notifier-error-inject.h"
+static int priority;
module_param(priority, int, 0);
MODULE_PARM_DESC(priority, "specify cpu notifier priority");
-module_param(cpu_up_prepare_error, int, 0644);
-MODULE_PARM_DESC(cpu_up_prepare_error,
- "specify error code to inject CPU_UP_PREPARE action");
-
-module_param(cpu_down_prepare_error, int, 0644);
-MODULE_PARM_DESC(cpu_down_prepare_error,
- "specify error code to inject CPU_DOWN_PREPARE action");
-
-static int err_inject_cpu_callback(struct notifier_block *nfb,
- unsigned long action, void *hcpu)
-{
- int err = 0;
-
- switch (action) {
- case CPU_UP_PREPARE:
- case CPU_UP_PREPARE_FROZEN:
- err = cpu_up_prepare_error;
- break;
- case CPU_DOWN_PREPARE:
- case CPU_DOWN_PREPARE_FROZEN:
- err = cpu_down_prepare_error;
- break;
+static struct notifier_err_inject cpu_notifier_err_inject = {
+ .actions = {
+ { NOTIFIER_ERR_INJECT_ACTION(CPU_UP_PREPARE) },
+ { NOTIFIER_ERR_INJECT_ACTION(CPU_UP_PREPARE_FROZEN) },
+ { NOTIFIER_ERR_INJECT_ACTION(CPU_DOWN_PREPARE) },
+ { NOTIFIER_ERR_INJECT_ACTION(CPU_DOWN_PREPARE_FROZEN) },
+ {}
}
- if (err)
- printk(KERN_INFO "Injecting error (%d) at cpu notifier\n", err);
-
- return notifier_from_errno(err);
-}
-
-static struct notifier_block err_inject_cpu_notifier = {
- .notifier_call = err_inject_cpu_callback,
};
+static struct dentry *dir;
+
static int err_inject_init(void)
{
- err_inject_cpu_notifier.priority = priority;
+ int err;
+
+ dir = notifier_err_inject_init("cpu", notifier_err_inject_dir,
+ &cpu_notifier_err_inject, priority);
+ if (IS_ERR(dir))
+ return PTR_ERR(dir);
+
+ err = register_hotcpu_notifier(&cpu_notifier_err_inject.nb);
+ if (err)
+ debugfs_remove_recursive(dir);
- return register_hotcpu_notifier(&err_inject_cpu_notifier);
+ return err;
}
static void err_inject_exit(void)
{
- unregister_hotcpu_notifier(&err_inject_cpu_notifier);
+ unregister_hotcpu_notifier(&cpu_notifier_err_inject.nb);
+ debugfs_remove_recursive(dir);
}
module_init(err_inject_init);
_
Subject: Subject: cpu: rewrite cpu-notifier-error-inject module
Patches currently in -mm which might be from akinobu.mita@xxxxxxxxx are
linux-next.patch
ocfs2-use-find_last_bit.patch
ocfs2-use-bitmap_weight.patch
string-introduce-memweight.patch
string-introduce-memweight-fix.patch
string-introduce-memweight-fix-build-error-caused-by-memweight-introduction.patch
qnx4fs-use-memweight.patch
dm-use-memweight.patch
affs-use-memweight.patch
video-uvc-use-memweight.patch
ocfs2-use-memweight.patch
ext2-use-memweight.patch
ext3-use-memweight.patch
ext4-use-memweight.patch
fault-injection-notifier-error-injection.patch
cpu-rewrite-cpu-notifier-error-inject-module.patch
pm-pm-notifier-error-injection-module.patch
memory-memory-notifier-error-injection-module.patch
powerpc-pseries-reconfig-notifier-error-injection-module.patch
fault-injection-add-selftests-for-cpu-and-memory-hotplug.patch
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