From: Titus Rwantare <titusr@google.com>

This patch fixes a bug that causes a kernel panic when calling ADM1266_BLACKBOX_INFORMATION.

Log Message:

adm1266 5-0042: Could not read blackbox!
Kernel panic - not syncing: stack-protector: Kernel stack is corrupted in: adm1266_nvmem_read+0x168/0x170

Signed-off-by: Titus Rwantare <titusr@google.com>
---
 hw/sensor/adm1266.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/hw/sensor/adm1266.c b/hw/sensor/adm1266.c
index 9017ce6116..cd11526c2b 100644
--- a/hw/sensor/adm1266.c
+++ b/hw/sensor/adm1266.c
@@ -75,6 +75,7 @@ typedef struct ADM1266State {
 static const uint8_t adm1266_ic_device_id[] = {0x03, 0x41, 0x12, 0x66};
 static const uint8_t adm1266_ic_device_rev[] = {0x08, 0x01, 0x08, 0x07, 0x0,
                                                 0x0, 0x07, 0x41, 0x30};
+static const uint8_t adm1266_blackbox_info[] = {0x04, 0x00, 0x00, 0x00, 0x00};
 
 static void adm1266_exit_reset(Object *obj, ResetType type)
 {
@@ -125,6 +126,17 @@ static uint8_t adm1266_read_byte(PMBusDevice *pmdev)
         pmbus_send(pmdev, adm1266_ic_device_rev, sizeof(adm1266_ic_device_rev));
         break;
 
+    case ADM1266_BLACKBOX_CONFIG:
+        return 0;
+
+    case ADM1266_READ_BLACKBOX:
+        return 0;
+
+    case ADM1266_BLACKBOX_INFORMATION:
+        pmbus_send(pmdev, adm1266_blackbox_info,
+                   sizeof(adm1266_blackbox_info));
+        break;
+
     default:
         qemu_log_mask(LOG_UNIMP,
                       "%s: reading from unimplemented register: 0x%02x\n",
@@ -154,6 +166,9 @@ static int adm1266_write_data(PMBusDevice *pmdev, const uint8_t *buf,
         pmbus_receive_block(pmdev, (uint8_t *)s->mfr_rev, sizeof(s->mfr_rev));
         break;
 
+    case ADM1266_BLACKBOX_CONFIG:
+    case ADM1266_READ_BLACKBOX:
+    case ADM1266_BLACKBOX_INFORMATION:
     case ADM1266_SET_RTC:   /* do nothing */
         break;
 
-- 
2.51.0.rc0.155.g4a0f42376b-goog