• Akinobu Mita's avatar
    cpu: rewrite cpu-notifier-error-inject module · f5a9f52e
    Akinobu Mita authored
    Rewrite existing cpu-notifier-error-inject module to use debugfs based new
    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
    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: 's avatarAkinobu 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: 's avatarAndrew Morton <akpm@linux-foundation.org>
    Signed-off-by: 's avatarLinus Torvalds <torvalds@linux-foundation.org>
cpu-notifier-error-inject.c 1.18 KB