xref: /openbmc/linux/arch/s390/kernel/nospec-sysfs.c (revision aeaf7002a76c8da60c0f503badcbddc07650678c)
14253b0e0SMartin Schwidefsky // SPDX-License-Identifier: GPL-2.0
24253b0e0SMartin Schwidefsky #include <linux/device.h>
34253b0e0SMartin Schwidefsky #include <linux/cpu.h>
44253b0e0SMartin Schwidefsky #include <asm/facility.h>
54253b0e0SMartin Schwidefsky #include <asm/nospec-branch.h>
64253b0e0SMartin Schwidefsky 
74253b0e0SMartin Schwidefsky ssize_t cpu_show_spectre_v1(struct device *dev,
84253b0e0SMartin Schwidefsky 			    struct device_attribute *attr, char *buf)
94253b0e0SMartin Schwidefsky {
104253b0e0SMartin Schwidefsky 	return sprintf(buf, "Mitigation: __user pointer sanitization\n");
114253b0e0SMartin Schwidefsky }
124253b0e0SMartin Schwidefsky 
134253b0e0SMartin Schwidefsky ssize_t cpu_show_spectre_v2(struct device *dev,
144253b0e0SMartin Schwidefsky 			    struct device_attribute *attr, char *buf)
154253b0e0SMartin Schwidefsky {
16*aeaf7002SMartin Schwidefsky 	if (test_facility(156))
17*aeaf7002SMartin Schwidefsky 		return sprintf(buf, "Mitigation: etokens\n");
184253b0e0SMartin Schwidefsky 	if (IS_ENABLED(CC_USING_EXPOLINE) && !nospec_disable)
194253b0e0SMartin Schwidefsky 		return sprintf(buf, "Mitigation: execute trampolines\n");
204253b0e0SMartin Schwidefsky 	if (__test_facility(82, S390_lowcore.alt_stfle_fac_list))
214253b0e0SMartin Schwidefsky 		return sprintf(buf, "Mitigation: limited branch prediction\n");
224253b0e0SMartin Schwidefsky 	return sprintf(buf, "Vulnerable\n");
234253b0e0SMartin Schwidefsky }
24