Commit 40247e55 authored by Matteo Croce's avatar Matteo Croce Committed by Linus Torvalds
Browse files

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@linux.microsoft.com


Signed-off-by: default avatarMatteo Croce <mcroce@microsoft.com>
Reviewed-by: default avatarPetr Mladek <pmladek@suse.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 1a9d079f

kernel/reboot.c

+31 −23
Original line number Diff line number Diff line
@@ -668,6 +668,29 @@ static ssize_t mode_store(struct kobject *kobj, struct kobj_attribute *attr, 
}

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 *kobj, struct kobj_attribute *attr, 
	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 *kobj, struct kobj_attribute *attr, 
	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,

};

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