1// SPDX-License-Identifier: GPL-2.0
2#include <linux/device.h>
3#include <linux/cpu.h>
4#include <asm/facility.h>
5#include <asm/nospec-branch.h>
6
7ssize_t cpu_show_spectre_v1(struct device *dev,
8 struct device_attribute *attr, char *buf)
9{
10 return sprintf(buf, fmt: "Mitigation: __user pointer sanitization\n");
11}
12
13ssize_t cpu_show_spectre_v2(struct device *dev,
14 struct device_attribute *attr, char *buf)
15{
16 if (test_facility(156))
17 return sprintf(buf, fmt: "Mitigation: etokens\n");
18 if (nospec_uses_trampoline())
19 return sprintf(buf, fmt: "Mitigation: execute trampolines\n");
20 if (__test_facility(82, alt_stfle_fac_list))
21 return sprintf(buf, fmt: "Mitigation: limited branch prediction\n");
22 return sprintf(buf, fmt: "Vulnerable\n");
23}
24

source code of linux/arch/s390/kernel/nospec-sysfs.c