summaryrefslogtreecommitdiff
path: root/arch/s390
diff options
context:
space:
mode:
authorMartin Schwidefsky <schwidefsky@de.ibm.com>2018-04-27 07:36:41 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-04-29 11:33:15 +0200
commitfce1bf054f0bc1dec6fef6cf5840c6ad7c662e17 (patch)
tree1e1f5e8196af035f21c0185b332fb603b71b528e /arch/s390
parent68cb884e12288cdbc044895affd528ceb98a815b (diff)
s390: add sysfs attributes for spectre
[ Upstream commit d424986f1d6b16079b3231db0314923f4f8deed1 ] 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/s390')
-rw-r--r--arch/s390/Kconfig1
-rw-r--r--arch/s390/kernel/nospec-branch.c19
2 files changed, 20 insertions, 0 deletions
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index 7a238d47c5c6..49fb6614ea8c 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -121,6 +121,7 @@ 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 7387ebace891..73c06d42792d 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/facility.h>
#include <asm/nospec-branch.h>
@@ -43,6 +44,24 @@ 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);