From c9d221f86e43d9fb16260fe18a8cd6767f36c8a5 Mon Sep 17 00:00:00 2001 From: Akinobu Mita Date: Wed, 26 May 2010 14:43:36 -0700 Subject: [PATCH] fault-injection: add CPU notifier error injection module I used this module to test the series of modification to the cpu notifiers code. Example1: inject CPU offline error (-1 == -EPERM) # modprobe cpu-notifier-error-inject cpu_down_prepare_error=-1 # echo 0 > /sys/devices/system/cpu/cpu1/online bash: echo: write error: Operation not permitted Example2: inject CPU online error (-2 == -ENOENT) # modprobe cpu-notifier-error-inject cpu_up_prepare_error=-2 # echo 1 > /sys/devices/system/cpu/cpu1/online bash: echo: write error: No such file or directory [akpm@linux-foundation.org: fix Kconfig help text] Signed-off-by: Akinobu Mita Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- lib/Kconfig.debug | 12 +++++++ lib/Makefile | 1 + lib/cpu-notifier-error-inject.c | 63 +++++++++++++++++++++++++++++++++ 3 files changed, 76 insertions(+) create mode 100644 lib/cpu-notifier-error-inject.c diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 231208948363..e722e9d62221 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -898,6 +898,18 @@ config LKDTM Documentation on how to use the module can be found in Documentation/fault-injection/provoke-crashes.txt +config CPU_NOTIFIER_ERROR_INJECT + tristate "CPU notifier error injection module" + depends on HOTPLUG_CPU && DEBUG_KERNEL + help + This option provides a kernel module that can be used to test + the error handling of the cpu notifiers + + To compile this code as a module, choose M here: the module will + be called cpu-notifier-error-inject. + + If unsure, say N. + config FAULT_INJECTION bool "Fault-injection framework" depends on DEBUG_KERNEL diff --git a/lib/Makefile b/lib/Makefile index 9e6d3c29d73a..c8567a59d316 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -85,6 +85,7 @@ 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-$(CONFIG_CPU_NOTIFIER_ERROR_INJECT) += cpu-notifier-error-inject.o lib-$(CONFIG_GENERIC_BUG) += bug.o diff --git a/lib/cpu-notifier-error-inject.c b/lib/cpu-notifier-error-inject.c new file mode 100644 index 000000000000..4dc20321b0d5 --- /dev/null +++ b/lib/cpu-notifier-error-inject.c @@ -0,0 +1,63 @@ +#include +#include +#include +#include + +static int priority; +static int cpu_up_prepare_error; +static int cpu_down_prepare_error; + +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; + } + 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 int err_inject_init(void) +{ + err_inject_cpu_notifier.priority = priority; + + return register_hotcpu_notifier(&err_inject_cpu_notifier); +} + +static void err_inject_exit(void) +{ + unregister_hotcpu_notifier(&err_inject_cpu_notifier); +} + +module_init(err_inject_init); +module_exit(err_inject_exit); + +MODULE_DESCRIPTION("CPU notifier error injection module"); +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Akinobu Mita "); -- 2.20.1