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 (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 }