Show the status of currently mitigated attack vectors in
/sys/devices/system/cpu/vector_mitigations/.
Signed-off-by: David Kaplan <david.kaplan@amd.com>
---
drivers/base/cpu.c | 67 ++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 67 insertions(+)
diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c
index 7779ab0ca7ce..0b76213ea70e 100644
--- a/drivers/base/cpu.c
+++ b/drivers/base/cpu.c
@@ -20,6 +20,7 @@
#include <linux/tick.h>
#include <linux/pm_qos.h>
#include <linux/delay.h>
+#include <linux/string_choices.h>
#include <linux/sched/isolation.h>
#include "base.h"
@@ -647,6 +648,70 @@ static const struct attribute_group cpu_root_vulnerabilities_group = {
.attrs = cpu_root_vulnerabilities_attrs,
};
+static const char *attack_vector_state(enum cpu_attack_vectors v)
+{
+ return str_on_off(cpu_attack_vector_mitigated(v));
+}
+
+static ssize_t cpu_show_user_kernel_vector(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ return sysfs_emit(buf, "%s\n", attack_vector_state(CPU_MITIGATE_USER_KERNEL));
+}
+
+static ssize_t cpu_show_user_user_vector(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ return sysfs_emit(buf, "%s\n", attack_vector_state(CPU_MITIGATE_USER_USER));
+}
+
+static ssize_t cpu_show_guest_host_vector(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ return sysfs_emit(buf, "%s\n", attack_vector_state(CPU_MITIGATE_GUEST_HOST));
+}
+
+static ssize_t cpu_show_guest_guest_vector(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ return sysfs_emit(buf, "%s\n", attack_vector_state(CPU_MITIGATE_GUEST_GUEST));
+}
+
+static ssize_t cpu_show_smt_vector(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ switch (smt_mitigations) {
+ case SMT_MITIGATIONS_OFF:
+ return sysfs_emit(buf, "off\n");
+ case SMT_MITIGATIONS_ON:
+ return sysfs_emit(buf, "on\n");
+ case SMT_MITIGATIONS_AUTO:
+ return sysfs_emit(buf, "auto\n");
+ }
+
+ return 0;
+}
+
+static DEVICE_ATTR(user_kernel, 0444, cpu_show_user_kernel_vector, NULL);
+static DEVICE_ATTR(user_user, 0444, cpu_show_user_user_vector, NULL);
+static DEVICE_ATTR(guest_host, 0444, cpu_show_guest_host_vector, NULL);
+static DEVICE_ATTR(guest_guest, 0444, cpu_show_guest_guest_vector, NULL);
+static DEVICE_ATTR(smt, 0444, cpu_show_smt_vector, NULL);
+
+static struct attribute *cpu_vector_mitigations_attrs[] = {
+ &dev_attr_user_kernel.attr,
+ &dev_attr_user_user.attr,
+ &dev_attr_guest_host.attr,
+ &dev_attr_guest_guest.attr,
+ &dev_attr_smt.attr,
+ NULL
+};
+
+static const struct attribute_group cpu_vector_mitigations_group = {
+ .name = "vector_mitigations",
+ .attrs = cpu_vector_mitigations_attrs,
+};
+
static void __init cpu_register_vulnerabilities(void)
{
struct device *dev = bus_get_dev_root(&cpu_subsys);
@@ -654,6 +719,8 @@ static void __init cpu_register_vulnerabilities(void)
if (dev) {
if (sysfs_create_group(&dev->kobj, &cpu_root_vulnerabilities_group))
pr_err("Unable to register CPU vulnerabilities\n");
+ if (sysfs_create_group(&dev->kobj, &cpu_vector_mitigations_group))
+ pr_err("Unable to register CPU attack vectors\n");
put_device(dev);
}
}
--
2.34.1