GNU Linux-libre 4.9.288-gnu1
[releases.git] / arch / s390 / kernel / nospec-sysfs.c
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
7 ssize_t cpu_show_spectre_v1(struct device *dev,
8                             struct device_attribute *attr, char *buf)
9 {
10         return sprintf(buf, "Mitigation: __user pointer sanitization\n");
11 }
12
13 ssize_t cpu_show_spectre_v2(struct device *dev,
14                             struct device_attribute *attr, char *buf)
15 {
16         if (IS_ENABLED(CC_USING_EXPOLINE) && !nospec_disable)
17                 return sprintf(buf, "Mitigation: execute trampolines\n");
18         if (__test_facility(82, S390_lowcore.alt_stfle_fac_list))
19                 return sprintf(buf, "Mitigation: limited branch prediction\n");
20         return sprintf(buf, "Vulnerable\n");
21 }