xref: /linux/arch/s390/kernel/nospec-sysfs.c (revision 4436e6da008fee87d54c038e983e5be9a6baf8fb)
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 (test_facility(156))
17 		return sprintf(buf, "Mitigation: etokens\n");
18 	if (nospec_uses_trampoline())
19 		return sprintf(buf, "Mitigation: execute trampolines\n");
20 	if (nobp_enabled())
21 		return sprintf(buf, "Mitigation: limited branch prediction\n");
22 	return sprintf(buf, "Vulnerable\n");
23 }
24