The patch titled Subject: fault-injection: notifier error injection has been removed from the -mm tree. Its filename was fault-injection-notifier-error-injection.patch This patch was dropped because it was merged into mainline or a subsystem tree ------------------------------------------------------ From: Akinobu Mita <akinobu.mita@xxxxxxxxx> Subject: fault-injection: notifier error injection This patchset 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 The patchset 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. This patch: The notifier error injection provides the ability to inject artifical errors to specified notifier chain callbacks. It is useful to test the error handling of notifier call chain failures. This adds common basic functions to define which type of events can be fail and to initialize the debugfs interface to control what error code should be returned and which event should be failed. 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> --- Documentation/fault-injection/notifier-error-inject.txt | 99 ++++++++ lib/Kconfig.debug | 11 lib/Makefile | 1 lib/notifier-error-inject.c | 112 ++++++++++ lib/notifier-error-inject.h | 24 ++ 5 files changed, 247 insertions(+) diff -puN /dev/null Documentation/fault-injection/notifier-error-inject.txt --- /dev/null +++ a/Documentation/fault-injection/notifier-error-inject.txt @@ -0,0 +1,99 @@ +Notifier error injection +======================== + +Notifier error injection provides the ability to inject artifical errors to +specified notifier chain callbacks. It is useful to test the error handling of +notifier call chain failures which is rarely executed. There are kernel +modules that can be used to test the following notifiers. + + * CPU notifier + * PM notifier + * Memory hotplug notifier + * powerpc pSeries reconfig notifier + +CPU notifier error injection module +----------------------------------- +This feature can be used to test the error handling of the CPU notifiers by +injecting artifical errors to CPU notifier chain callbacks. + +If the notifier call chain should be failed with some events notified, write +the error code to debugfs interface +/sys/kernel/debug/notifier-error-inject/cpu/actions/<notifier event>/error + +Possible CPU notifier events to be failed are: + + * CPU_UP_PREPARE + * CPU_UP_PREPARE_FROZEN + * CPU_DOWN_PREPARE + * CPU_DOWN_PREPARE_FROZEN + +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) + + # echo -2 > actions/CPU_UP_PREPARE/error + # echo 1 > /sys/devices/system/cpu/cpu1/online + bash: echo: write error: No such file or directory + +PM notifier error injection module +---------------------------------- +This feature is controlled through debugfs interface +/sys/kernel/debug/notifier-error-inject/pm/actions/<notifier event>/error + +Possible PM notifier events to be failed are: + + * PM_HIBERNATION_PREPARE + * PM_SUSPEND_PREPARE + * PM_RESTORE_PREPARE + +Example: Inject PM suspend error (-12 = -ENOMEM) + + # cd /sys/kernel/debug/notifier-error-inject/pm/ + # echo -12 > actions/PM_SUSPEND_PREPARE/error + # echo mem > /sys/power/state + bash: echo: write error: Cannot allocate memory + +Memory hotplug notifier error injection module +---------------------------------------------- +This feature is controlled through debugfs interface +/sys/kernel/debug/notifier-error-inject/memory/actions/<notifier event>/error + +Possible memory notifier events to be failed are: + + * MEM_GOING_ONLINE + * MEM_GOING_OFFLINE + +Example: Inject memory hotplug offline error (-12 == -ENOMEM) + + # cd /sys/kernel/debug/notifier-error-inject/memory + # echo -12 > actions/MEM_GOING_OFFLINE/error + # echo offline > /sys/devices/system/memory/memoryXXX/state + bash: echo: write error: Cannot allocate memory + +powerpc pSeries reconfig notifier error injection module +-------------------------------------------------------- +This feature is controlled through debugfs interface +/sys/kernel/debug/notifier-error-inject/pSeries-reconfig/actions/<notifier event>/error + +Possible pSeries reconfig notifier events to be failed are: + + * PSERIES_RECONFIG_ADD + * PSERIES_RECONFIG_REMOVE + * PSERIES_DRCONF_MEM_ADD + * PSERIES_DRCONF_MEM_REMOVE + +For more usage examples +----------------------- +There are tools/testing/selftests using the notifier error injection features +for CPU and memory notifiers. + + * tools/testing/selftests/cpu-hotplug/on-off-test.sh + * tools/testing/selftests/memory-hotplug/on-off-test.sh + +These scripts first do simple online and offline tests and then do fault +injection tests if notifier error injection module is available. diff -puN lib/Kconfig.debug~fault-injection-notifier-error-injection lib/Kconfig.debug --- a/lib/Kconfig.debug~fault-injection-notifier-error-injection +++ a/lib/Kconfig.debug @@ -1084,6 +1084,17 @@ config LKDTM Documentation on how to use the module can be found in Documentation/fault-injection/provoke-crashes.txt +config NOTIFIER_ERROR_INJECTION + tristate "Notifier error injection" + depends on DEBUG_KERNEL + select DEBUG_FS + help + This option provides the ability to inject artifical errors to + specified notifier chain callbacks. It is useful to test the error + handling of notifier call chain failures. + + Say N if unsure. + config CPU_NOTIFIER_ERROR_INJECT tristate "CPU notifier error injection module" depends on HOTPLUG_CPU && DEBUG_KERNEL diff -puN lib/Makefile~fault-injection-notifier-error-injection lib/Makefile --- a/lib/Makefile~fault-injection-notifier-error-injection +++ a/lib/Makefile @@ -90,6 +90,7 @@ obj-$(CONFIG_AUDIT_GENERIC) += audit.o obj-$(CONFIG_SWIOTLB) += swiotlb.o obj-$(CONFIG_IOMMU_HELPER) += iommu-helper.o obj-$(CONFIG_FAULT_INJECTION) += fault-inject.o +obj-$(CONFIG_NOTIFIER_ERROR_INJECTION) += notifier-error-inject.o obj-$(CONFIG_CPU_NOTIFIER_ERROR_INJECT) += cpu-notifier-error-inject.o lib-$(CONFIG_GENERIC_BUG) += bug.o diff -puN /dev/null lib/notifier-error-inject.c --- /dev/null +++ a/lib/notifier-error-inject.c @@ -0,0 +1,112 @@ +#include <linux/module.h> + +#include "notifier-error-inject.h" + +static int debugfs_errno_set(void *data, u64 val) +{ + *(int *)data = clamp_t(int, val, -MAX_ERRNO, 0); + return 0; +} + +static int debugfs_errno_get(void *data, u64 *val) +{ + *val = *(int *)data; + return 0; +} + +DEFINE_SIMPLE_ATTRIBUTE(fops_errno, debugfs_errno_get, debugfs_errno_set, + "%lld\n"); + +static struct dentry *debugfs_create_errno(const char *name, mode_t mode, + struct dentry *parent, int *value) +{ + return debugfs_create_file(name, mode, parent, value, &fops_errno); +} + +static int notifier_err_inject_callback(struct notifier_block *nb, + unsigned long val, void *p) +{ + int err = 0; + struct notifier_err_inject *err_inject = + container_of(nb, struct notifier_err_inject, nb); + struct notifier_err_inject_action *action; + + for (action = err_inject->actions; action->name; action++) { + if (action->val == val) { + err = action->error; + break; + } + } + if (err) + pr_info("Injecting error (%d) to %s\n", err, action->name); + + return notifier_from_errno(err); +} + +struct dentry *notifier_err_inject_dir; +EXPORT_SYMBOL_GPL(notifier_err_inject_dir); + +struct dentry *notifier_err_inject_init(const char *name, struct dentry *parent, + struct notifier_err_inject *err_inject, int priority) +{ + struct notifier_err_inject_action *action; + mode_t mode = S_IFREG | S_IRUSR | S_IWUSR; + struct dentry *dir; + struct dentry *actions_dir; + + err_inject->nb.notifier_call = notifier_err_inject_callback; + err_inject->nb.priority = priority; + + dir = debugfs_create_dir(name, parent); + if (!dir) + return ERR_PTR(-ENOMEM); + + actions_dir = debugfs_create_dir("actions", dir); + if (!actions_dir) + goto fail; + + for (action = err_inject->actions; action->name; action++) { + struct dentry *action_dir; + + action_dir = debugfs_create_dir(action->name, actions_dir); + if (!action_dir) + goto fail; + + /* + * Create debugfs r/w file containing action->error. If + * notifier call chain is called with action->val, it will + * fail with the error code + */ + if (!debugfs_create_errno("error", mode, action_dir, + &action->error)) + goto fail; + } + return dir; +fail: + debugfs_remove_recursive(dir); + return ERR_PTR(-ENOMEM); +} +EXPORT_SYMBOL_GPL(notifier_err_inject_init); + +static int __init err_inject_init(void) +{ + notifier_err_inject_dir = + debugfs_create_dir("notifier-error-inject", NULL); + + if (!notifier_err_inject_dir) + return -ENOMEM; + + return 0; +} + +static void __exit err_inject_exit(void) +{ + debugfs_remove_recursive(notifier_err_inject_dir); +} + +module_init(err_inject_init); +module_exit(err_inject_exit); + +MODULE_DESCRIPTION("Notifier error injection module"); +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Akinobu Mita <akinobu.mita@xxxxxxxxx>"); diff -puN /dev/null lib/notifier-error-inject.h --- /dev/null +++ a/lib/notifier-error-inject.h @@ -0,0 +1,24 @@ +#include <linux/atomic.h> +#include <linux/debugfs.h> +#include <linux/notifier.h> + +struct notifier_err_inject_action { + unsigned long val; + int error; + const char *name; +}; + +#define NOTIFIER_ERR_INJECT_ACTION(action) \ + .name = #action, .val = (action), + +struct notifier_err_inject { + struct notifier_block nb; + struct notifier_err_inject_action actions[]; + /* The last slot must be terminated with zero sentinel */ +}; + +extern struct dentry *notifier_err_inject_dir; + +extern struct dentry *notifier_err_inject_init(const char *name, + struct dentry *parent, struct notifier_err_inject *err_inject, + int priority); _ Patches currently in -mm which might be from akinobu.mita@xxxxxxxxx are origin.patch fault-injection-fix-failcmdsh-warning.patch linux-next.patch ocfs2-use-find_last_bit.patch ocfs2-use-bitmap_weight.patch -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html