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 (IS_ENABLED(CC_USING_EXPOLINE) && !nospec_disable) 19 return sprintf(buf, "Mitigation: execute trampolines\n"); 20 if (__test_facility(82, S390_lowcore.alt_stfle_fac_list)) 21 return sprintf(buf, "Mitigation: limited branch prediction\n"); 22 return sprintf(buf, "Vulnerable\n"); 23 } 24