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-rw-r--r--Documentation/ABI/testing/sysfs-devices-system-cpu1
-rw-r--r--arch/x86/kernel/cpu/bugs.c25
-rw-r--r--drivers/base/cpu.c8
-rw-r--r--include/linux/cpu.h2
4 files changed, 36 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-devices-system-cpu b/Documentation/ABI/testing/sysfs-devices-system-cpu
index 9605dbd4b5b5..2db5c3407fd6 100644
--- a/Documentation/ABI/testing/sysfs-devices-system-cpu
+++ b/Documentation/ABI/testing/sysfs-devices-system-cpu
@@ -484,6 +484,7 @@ What: /sys/devices/system/cpu/vulnerabilities
/sys/devices/system/cpu/vulnerabilities/spectre_v2
/sys/devices/system/cpu/vulnerabilities/spec_store_bypass
/sys/devices/system/cpu/vulnerabilities/l1tf
+ /sys/devices/system/cpu/vulnerabilities/mds
Date: January 2018
Contact: Linux kernel mailing list <linux-kernel@vger.kernel.org>
Description: Information about CPU vulnerabilities
diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c
index c7b29d200d27..7ab16a6ed064 100644
--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -1172,6 +1172,22 @@ static ssize_t l1tf_show_state(char *buf)
}
#endif
+static ssize_t mds_show_state(char *buf)
+{
+ if (!hypervisor_is_type(X86_HYPER_NATIVE)) {
+ return sprintf(buf, "%s; SMT Host state unknown\n",
+ mds_strings[mds_mitigation]);
+ }
+
+ if (boot_cpu_has(X86_BUG_MSBDS_ONLY)) {
+ return sprintf(buf, "%s; SMT %s\n", mds_strings[mds_mitigation],
+ sched_smt_active() ? "mitigated" : "disabled");
+ }
+
+ return sprintf(buf, "%s; SMT %s\n", mds_strings[mds_mitigation],
+ sched_smt_active() ? "vulnerable" : "disabled");
+}
+
static char *stibp_state(void)
{
if (spectre_v2_enabled == SPECTRE_V2_IBRS_ENHANCED)
@@ -1238,6 +1254,10 @@ static ssize_t cpu_show_common(struct device *dev, struct device_attribute *attr
if (boot_cpu_has(X86_FEATURE_L1TF_PTEINV))
return l1tf_show_state(buf);
break;
+
+ case X86_BUG_MDS:
+ return mds_show_state(buf);
+
default:
break;
}
@@ -1269,4 +1289,9 @@ ssize_t cpu_show_l1tf(struct device *dev, struct device_attribute *attr, char *b
{
return cpu_show_common(dev, attr, buf, X86_BUG_L1TF);
}
+
+ssize_t cpu_show_mds(struct device *dev, struct device_attribute *attr, char *buf)
+{
+ return cpu_show_common(dev, attr, buf, X86_BUG_MDS);
+}
#endif
diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c
index eb9443d5bae1..2fd6ca1021c2 100644
--- a/drivers/base/cpu.c
+++ b/drivers/base/cpu.c
@@ -546,11 +546,18 @@ ssize_t __weak cpu_show_l1tf(struct device *dev,
return sprintf(buf, "Not affected\n");
}
+ssize_t __weak cpu_show_mds(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ return sprintf(buf, "Not affected\n");
+}
+
static DEVICE_ATTR(meltdown, 0444, cpu_show_meltdown, NULL);
static DEVICE_ATTR(spectre_v1, 0444, cpu_show_spectre_v1, NULL);
static DEVICE_ATTR(spectre_v2, 0444, cpu_show_spectre_v2, NULL);
static DEVICE_ATTR(spec_store_bypass, 0444, cpu_show_spec_store_bypass, NULL);
static DEVICE_ATTR(l1tf, 0444, cpu_show_l1tf, NULL);
+static DEVICE_ATTR(mds, 0444, cpu_show_mds, NULL);
static struct attribute *cpu_root_vulnerabilities_attrs[] = {
&dev_attr_meltdown.attr,
@@ -558,6 +565,7 @@ static struct attribute *cpu_root_vulnerabilities_attrs[] = {
&dev_attr_spectre_v2.attr,
&dev_attr_spec_store_bypass.attr,
&dev_attr_l1tf.attr,
+ &dev_attr_mds.attr,
NULL
};
diff --git a/include/linux/cpu.h b/include/linux/cpu.h
index 5041357d0297..3c87ad888ed3 100644
--- a/include/linux/cpu.h
+++ b/include/linux/cpu.h
@@ -57,6 +57,8 @@ extern ssize_t cpu_show_spec_store_bypass(struct device *dev,
struct device_attribute *attr, char *buf);
extern ssize_t cpu_show_l1tf(struct device *dev,
struct device_attribute *attr, char *buf);
+extern ssize_t cpu_show_mds(struct device *dev,
+ struct device_attribute *attr, char *buf);
extern __printf(4, 5)
struct device *cpu_device_create(struct device *parent, void *drvdata,