mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson
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c9d221f86e
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 <akinobu.mita@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
64 lines
1.5 KiB
C
64 lines
1.5 KiB
C
#include <linux/kernel.h>
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#include <linux/cpu.h>
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#include <linux/module.h>
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#include <linux/notifier.h>
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static int priority;
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static int cpu_up_prepare_error;
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static int cpu_down_prepare_error;
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module_param(priority, int, 0);
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MODULE_PARM_DESC(priority, "specify cpu notifier priority");
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module_param(cpu_up_prepare_error, int, 0644);
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MODULE_PARM_DESC(cpu_up_prepare_error,
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"specify error code to inject CPU_UP_PREPARE action");
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module_param(cpu_down_prepare_error, int, 0644);
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MODULE_PARM_DESC(cpu_down_prepare_error,
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"specify error code to inject CPU_DOWN_PREPARE action");
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static int err_inject_cpu_callback(struct notifier_block *nfb,
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unsigned long action, void *hcpu)
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{
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int err = 0;
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switch (action) {
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case CPU_UP_PREPARE:
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case CPU_UP_PREPARE_FROZEN:
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err = cpu_up_prepare_error;
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break;
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case CPU_DOWN_PREPARE:
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case CPU_DOWN_PREPARE_FROZEN:
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err = cpu_down_prepare_error;
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break;
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}
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if (err)
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printk(KERN_INFO "Injecting error (%d) at cpu notifier\n", err);
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return notifier_from_errno(err);
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}
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static struct notifier_block err_inject_cpu_notifier = {
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.notifier_call = err_inject_cpu_callback,
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};
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static int err_inject_init(void)
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{
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err_inject_cpu_notifier.priority = priority;
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return register_hotcpu_notifier(&err_inject_cpu_notifier);
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}
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static void err_inject_exit(void)
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{
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unregister_hotcpu_notifier(&err_inject_cpu_notifier);
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}
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module_init(err_inject_init);
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module_exit(err_inject_exit);
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MODULE_DESCRIPTION("CPU notifier error injection module");
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MODULE_LICENSE("GPL");
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MODULE_AUTHOR("Akinobu Mita <akinobu.mita@gmail.com>");
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