Sure Start provides advanced firmware protection and resiliency by
identifying and repairing unauthorized BIOS changes. It maintains an
audit log of these events and other important system configuration
changes. The following sysfs entries can be used to read the contents
of the audit log.
/sys/devices/platform/hp-wmi/sure_start/audit_log_entry_count
/sys/devices/platform/hp-wmi/sure_start/audit_log_entries
'audit_log_entry_count' is a read-only file that returns the number of
existing audit log events available to be read
'audit_log_entries' is a read-only file that returns the events in the
log
This feature requires "Update hp_wmi_group to simplify feature
addition" patch.
All changes were validated on a HP ZBook Workstation,
HP EliteBook x360, and HP EliteBook 850 G8 notebooks.
Signed-off-by: Jorge Lopez <jorge.lopez2@xxxxxx>
---
Based on the latest platform-drivers-x86.git/for-next
---
drivers/platform/x86/hp-wmi.c | 108 ++++++++++++++++++++++++++++++++++
1 file changed, 108 insertions(+)
diff --git a/drivers/platform/x86/hp-wmi.c b/drivers/platform/x86/hp-wmi.c
index 139dc079c1fa..918e3eaf1b67 100644
--- a/drivers/platform/x86/hp-wmi.c
+++ b/drivers/platform/x86/hp-wmi.c
@@ -126,6 +126,11 @@ enum hp_wmi_spm_commandtype {
HPWMI_SECUREPLATFORM_SET_SK = 0x12,
};
+enum hp_wmi_surestart_commandtype {
+ HPWMI_SURESTART_GET_LOG_COUNT = 0x01,
+ HPWMI_SURESTART_GET_LOG = 0x02,
+};
+
enum hp_wmi_gm_commandtype {
HPWMI_FAN_SPEED_GET_QUERY = 0x11,
HPWMI_SET_PERFORMANCE_MODE = 0x1A,
@@ -138,6 +143,7 @@ enum hp_wmi_command {
HPWMI_READ = 0x01,
HPWMI_WRITE = 0x02,
HPWMI_ODM = 0x03,
+ HPWMI_SURESTART = 0x20006,
HPWMI_GM = 0x20008,
HPWMI_SECUREPLATFORM = 0x20010,
};
@@ -851,6 +857,7 @@ static ssize_t spm_kek_store(struct kobject *kobj,
{
int ret = hp_wmi_perform_query(HPWMI_SECUREPLATFORM_SET_KEK,
HPWMI_SECUREPLATFORM, (void *)buf, count, 0);
+
return ret ? -EINVAL : count;
}
@@ -918,6 +925,106 @@ static const struct attribute_group spm_group = {
.attrs = spm_attrs,
};
+/* Sure Start functions */
+
+#define LOG_MAX_ENTRIES 254
+#define LOG_ENTRY_SIZE 16
+
+/*
+ * sure_start_audit_log_entry_count_show - Reports the number of
+ * existing audit log entries available
+ * to be read
+ *
+ * @kobj: Pointer to a kernel object of things that show up as directory
+ * in the sysfs filesystem.
+ * @attr: Pointer to list of attributes for the operation
+ * @buf: Pointer to buffer
+ *
+ * Returns number of existing audit log entries available to be read,
+ * audit log entry size, and maximum number of entries
+ * supported. Otherwise, an HP WMI query specific error code
+ * (which is negative)
+ *
+ * [No of entries],[log entry size],[Max number of entries supported]
+ */
+static ssize_t sure_start_audit_log_entry_count_show(struct kobject *kobj,
+ struct kobj_attribute *attr, char *buf)
+{
+ int ret;
+ u32 count = 0;
+
+ ret = hp_wmi_perform_query(HPWMI_SURESTART_GET_LOG_COUNT, HPWMI_SURESTART,
+ &count, 0, sizeof(count));
+ if (ret < 0)
+ return ret;
+
+ return snprintf(buf, PAGE_SIZE, "%d,%d,%d\n", count, LOG_ENTRY_SIZE, LOG_MAX_ENTRIES);
+}
+
+/*
+ * sure_start_audit_log_entries_show() - Return all entries found in log file
+ *
+ * @kobj: Pointer to a kernel object of things that show up as
+ * directory in the sysfs filesystem.
+ * @attr: Pointer to list of attributes for the operation
+ * @buf: Pointer to buffer
+ *
+ * Returns number of bytes needed to read all audit logs entries to be read.
+ * Otherwise, an HP WMI query specific error code (which is negative)
+ * -EFAULT if the audit logs size exceeds 4KB
+ *
+ */
+static ssize_t sure_start_audit_log_entries_show(struct kobject *kobj,
+ struct kobj_attribute *attr, char *buf)
+{
+ int ret;
+ int i;
+ u32 count = 0;
+
+ // Get the number of event logs
+ ret = hp_wmi_perform_query(HPWMI_SURESTART_GET_LOG_COUNT, HPWMI_SURESTART,
+ &count, 1, 4);
+
+ /*
+ * The show() api will not work if the audit logs ever go
+ * beyond 4KB
+ */
+ if (count * LOG_ENTRY_SIZE > PAGE_SIZE)
+ return -EFAULT;
+
+ if (ret < 0)
+ return ret;
+
+ /*
+ * We are guaranteed the buffer is 4KB so today all the event
+ * logs will fit
+ */
+ for (i = 0; ((i < count) & (ret >= 0)); i++) {
+ *buf = (i + 1);
+ ret = hp_wmi_perform_query(HPWMI_SURESTART_GET_LOG,
+ HPWMI_SURESTART,
+ buf, 1, 128);
+ if (ret >= 0)
+ buf += LOG_ENTRY_SIZE;
+ }
+
+ return (count * LOG_ENTRY_SIZE);
+}
+
+HPWMI_ATTR_RO(sure_start, audit_log_entry_count);
+HPWMI_ATTR_RO(sure_start, audit_log_entries);
+
+static struct attribute *sure_start_attrs[] = {
+ &sure_start_audit_log_entry_count.attr,
+ &sure_start_audit_log_entries.attr,
+ NULL,
+};
+
+static const struct attribute_group sure_start_group = {
+ .name = "sure_start",
+ .attrs = sure_start_attrs,
+};
+
static DEVICE_ATTR_RO(display);
static DEVICE_ATTR_RO(hddtemp);
static DEVICE_ATTR_RW(als);
@@ -942,6 +1049,7 @@ static const struct attribute_group hp_wmi_group = {
static const struct attribute_group *hp_wmi_groups[] = {
&hp_wmi_group,
&spm_group,
+ &sure_start_group,
NULL,
};
--
2.25.1
