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https://github.com/torvalds/linux
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f5a9f52e2c
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>
50 lines
1.2 KiB
C
50 lines
1.2 KiB
C
#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/cpu.h>
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#include "notifier-error-inject.h"
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static int priority;
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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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static struct notifier_err_inject cpu_notifier_err_inject = {
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.actions = {
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{ NOTIFIER_ERR_INJECT_ACTION(CPU_UP_PREPARE) },
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{ NOTIFIER_ERR_INJECT_ACTION(CPU_UP_PREPARE_FROZEN) },
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{ NOTIFIER_ERR_INJECT_ACTION(CPU_DOWN_PREPARE) },
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{ NOTIFIER_ERR_INJECT_ACTION(CPU_DOWN_PREPARE_FROZEN) },
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{}
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}
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};
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static struct dentry *dir;
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static int err_inject_init(void)
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{
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int err;
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dir = notifier_err_inject_init("cpu", notifier_err_inject_dir,
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&cpu_notifier_err_inject, priority);
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if (IS_ERR(dir))
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return PTR_ERR(dir);
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err = register_hotcpu_notifier(&cpu_notifier_err_inject.nb);
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if (err)
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debugfs_remove_recursive(dir);
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return err;
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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(&cpu_notifier_err_inject.nb);
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debugfs_remove_recursive(dir);
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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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