From: Matteo Croce <mcroce@xxxxxxxxxxxxx> Subject: reboot: hide from sysfs not applicable settings Not all the reboot settings from both the kernel command line or sysfs interface are available to all platforms. Filter out reboot_type and reboot_force which are x86 only, and also remove reboot_cpu on kernels without SMP support. This saves some space, and avoid confusing the user with settings which will have no effect. Link: https://lkml.kernel.org/r/20201130173717.198952-3-mcroce@xxxxxxxxxxxxxxxxxxx Signed-off-by: Matteo Croce <mcroce@xxxxxxxxxxxxx> Reviewed-by: Petr Mladek <pmladek@xxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- kernel/reboot.c | 54 ++++++++++++++++++++++++++-------------------- 1 file changed, 31 insertions(+), 23 deletions(-) --- a/kernel/reboot.c~reboot-hide-from-sysfs-not-applicable-settings +++ a/kernel/reboot.c @@ -668,6 +668,29 @@ static ssize_t mode_store(struct kobject } static struct kobj_attribute reboot_mode_attr = __ATTR_RW(mode); +#ifdef CONFIG_X86 +static ssize_t force_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf) +{ + return sprintf(buf, "%d\n", reboot_force); +} +static ssize_t force_store(struct kobject *kobj, struct kobj_attribute *attr, + const char *buf, size_t count) +{ + bool res; + + if (!capable(CAP_SYS_BOOT)) + return -EPERM; + + if (kstrtobool(buf, &res)) + return -EINVAL; + + reboot_default = 0; + reboot_force = res; + + return count; +} +static struct kobj_attribute reboot_force_attr = __ATTR_RW(force); + static ssize_t type_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf) { const char *val; @@ -723,7 +746,9 @@ static ssize_t type_store(struct kobject return count; } static struct kobj_attribute reboot_type_attr = __ATTR_RW(type); +#endif +#ifdef CONFIG_SMP static ssize_t cpu_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf) { return sprintf(buf, "%d\n", reboot_cpu); @@ -751,34 +776,17 @@ static ssize_t cpu_store(struct kobject return count; } static struct kobj_attribute reboot_cpu_attr = __ATTR_RW(cpu); - -static ssize_t force_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf) -{ - return sprintf(buf, "%d\n", reboot_force); -} -static ssize_t force_store(struct kobject *kobj, struct kobj_attribute *attr, - const char *buf, size_t count) -{ - bool res; - - if (!capable(CAP_SYS_BOOT)) - return -EPERM; - - if (kstrtobool(buf, &res)) - return -EINVAL; - - reboot_default = 0; - reboot_force = res; - - return count; -} -static struct kobj_attribute reboot_force_attr = __ATTR_RW(force); +#endif static struct attribute *reboot_attrs[] = { &reboot_mode_attr.attr, +#ifdef CONFIG_X86 + &reboot_force_attr.attr, &reboot_type_attr.attr, +#endif +#ifdef CONFIG_SMP &reboot_cpu_attr.attr, - &reboot_force_attr.attr, +#endif NULL, }; _
