diff options
| author |   Martin Schwidefsky <schwidefsky@de.ibm.com> | 2018-03-21 09:38:21 +0100 |
|---|---|---|
| committer | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2018-03-28 08:38:26 +0200 |
| commit | d424986f1d6b16079b3231db0314923f4f8deed1 (patch) | |
| tree | d7073666315494e8cb6f882f71d5a87b217f85e0 | |
| parent | s390: report spectre mitigation via syslog (diff) | |
| download | linux-dev-d424986f1d6b16079b3231db0314923f4f8deed1.tar.xz linux-dev-d424986f1d6b16079b3231db0314923f4f8deed1.zip | |
s390: add sysfs attributes for spectre
Set CONFIG_GENERIC_CPU_VULNERABILITIES and provide the two functions
cpu_show_spectre_v1 and cpu_show_spectre_v2 to report the spectre
mitigations.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
| -rw-r--r-- | arch/s390/Kconfig | 1 | ||||
| -rw-r--r-- | arch/s390/kernel/nospec-branch.c | 19 |
2 files changed, 20 insertions, 0 deletions
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig index 90cc6d488492..32a0d5b958bf 100644 --- a/arch/s390/Kconfig +++ b/arch/s390/Kconfig @@ -120,6 +120,7 @@ config S390 select GENERIC_CLOCKEVENTS select GENERIC_CPU_AUTOPROBE select GENERIC_CPU_DEVICES if !SMP + select GENERIC_CPU_VULNERABILITIES select GENERIC_FIND_FIRST_BIT select GENERIC_SMP_IDLE_THREAD select GENERIC_TIME_VSYSCALL diff --git a/arch/s390/kernel/nospec-branch.c b/arch/s390/kernel/nospec-branch.c index adec38c5f53b..14867ec5f726 100644 --- a/arch/s390/kernel/nospec-branch.c +++ b/arch/s390/kernel/nospec-branch.c @@ -1,5 +1,6 @@ // SPDX-License-Identifier: GPL-2.0 #include <linux/module.h> +#include <linux/device.h> #include <asm/nospec-branch.h> static int __init nobp_setup_early(char *str) @@ -42,6 +43,24 @@ static int __init nospec_report(void) } arch_initcall(nospec_report); +#ifdef CONFIG_SYSFS +ssize_t cpu_show_spectre_v1(struct device *dev, + struct device_attribute *attr, char *buf) +{ + return sprintf(buf, "Mitigation: __user pointer sanitization\n"); +} + +ssize_t cpu_show_spectre_v2(struct device *dev, + struct device_attribute *attr, char *buf) +{ + if (IS_ENABLED(CC_USING_EXPOLINE) && !nospec_disable) + return sprintf(buf, "Mitigation: execute trampolines\n"); + if (__test_facility(82, S390_lowcore.alt_stfle_fac_list)) + return sprintf(buf, "Mitigation: limited branch prediction.\n"); + return sprintf(buf, "Vulnerable\n"); +} +#endif + #ifdef CONFIG_EXPOLINE int nospec_disable = IS_ENABLED(CONFIG_EXPOLINE_OFF); |