[PATCH 1/2] Avoid ASSERT(IsZeroMemory()) in checked builds

[Owen Smith <owen.smith@xxxxxxxxxx>]

* Zero Srb counters in BlkifRingDestroy
* NULL Path pointer in BlkifRingCreate fail path
* Zero embedded structures and values in FrontendDestroy
* Zero TargetPath and FrontendPath on FrontendCreate fail path
* Zero any Page80/83 overrides on FrontendConnect fail path
* NULL TargetList entry in AdapterTeardown

Signed-off-by: Owen Smith <owen.smith@xxxxxxxxxx>
---
 src/xenvbd/adapter.c  |  1 +
 src/xenvbd/frontend.c | 40 +++++++++++++++++++++++++++++-----------
 src/xenvbd/ring.c     |  6 +++++-
 3 files changed, 35 insertions(+), 12 deletions(-)

diff --git a/src/xenvbd/adapter.c b/src/xenvbd/adapter.c
index 0f9500c..a0be841 100644
--- a/src/xenvbd/adapter.c
+++ b/src/xenvbd/adapter.c
@@ -1507,6 +1507,7 @@ AdapterTeardown(
         TargetSetMissing(Target, "AdapterTeardown");
         // drop ref-count acquired in __AdapterGetTarget *before* destroying 
Target
         TargetDestroy(Target);
+        Adapter->TargetList[TargetId] = NULL;
     }
 
     Adapter->BootEmulated = FALSE;
diff --git a/src/xenvbd/frontend.c b/src/xenvbd/frontend.c
index 3b078da..5311dd5 100644
--- a/src/xenvbd/frontend.c
+++ b/src/xenvbd/frontend.c
@@ -1287,6 +1287,19 @@ abort:
 fail7:
     Error("Fail7\n");
     RtlZeroMemory(&Frontend->Features, sizeof(XENVBD_FEATURES));
+
+    if (Frontend->Page80.Data)
+        Base64Free(Frontend->Page80.Data);
+    Frontend->Page80.Data = NULL;
+    Frontend->Page80.Size = 0;
+
+    if (Frontend->Page83.Data)
+        Base64Free(Frontend->Page83.Data);
+    Frontend->Page83.Data = NULL;
+    Frontend->Page83.Size = 0;
+
+    RtlZeroMemory(&Frontend->DiskInfo, sizeof(XENVBD_DISKINFO));
+
 fail6:
     Error("Fail6\n");
 fail5:
@@ -1923,8 +1936,10 @@ fail5:
     Frontend->Ring = NULL;
 fail4:
     Error("fail4\n");
+    RtlZeroMemory(Frontend->TargetPath, sizeof(Frontend->TargetPath));
 fail3:
     Error("fail3\n");
+    RtlZeroMemory(Frontend->FrontendPath, sizeof(Frontend->FrontendPath));
 fail2:
     Error("Fail2\n");
     Frontend->Target = NULL;
@@ -1951,16 +1966,6 @@ FrontendDestroy(
 
     Trace("Target[%d] @ (%d) =====>\n", TargetId, KeGetCurrentIrql());
 
-    if (Frontend->Page80.Data)
-        Base64Free(Frontend->Page80.Data);
-    Frontend->Page80.Data = NULL;
-    Frontend->Page80.Size = 0;
-
-    if (Frontend->Page83.Data)
-        Base64Free(Frontend->Page83.Data);
-    Frontend->Page83.Data = NULL;
-    Frontend->Page83.Size = 0;
-
     ThreadAlert(Frontend->BackendThread);
     ThreadJoin(Frontend->BackendThread);
     Frontend->BackendThread = NULL;
@@ -1971,11 +1976,24 @@ FrontendDestroy(
     RingDestroy(Frontend->Ring);
     Frontend->Ring = NULL;
 
-    Frontend->MaxQueues = 0;
+    RtlZeroMemory(&Frontend->StateLock, sizeof(KSPIN_LOCK));
+
+    RtlZeroMemory(Frontend->TargetPath, sizeof(Frontend->TargetPath));
+    RtlZeroMemory(Frontend->FrontendPath, sizeof(Frontend->FrontendPath));
+    RtlZeroMemory(&Frontend->DiskInfo, sizeof(XENVBD_DISKINFO));
+    RtlZeroMemory(&Frontend->Caps, sizeof(XENVBD_CAPS));
 
     ASSERT3P(Frontend->BackendPath, ==, NULL);
     ASSERT3P(Frontend->BackendWatch, ==, NULL);
 
+    Frontend->Target = NULL;
+    Frontend->TargetId = 0;
+    Frontend->DeviceId = 0;
+    Frontend->State = XENVBD_STATE_INVALID; // 0
+    Frontend->BackendDomain = 0;
+    Frontend->MaxQueues = 0;
+
+    ASSERT(IsZeroMemory(Frontend, sizeof(XENVBD_FRONTEND)));
     __FrontendFree(Frontend);
     Trace("Target[%d] @ (%d) <=====\n", TargetId, KeGetCurrentIrql());
 }
diff --git a/src/xenvbd/ring.c b/src/xenvbd/ring.c
index 0b56831..ffbd18a 100644
--- a/src/xenvbd/ring.c
+++ b/src/xenvbd/ring.c
@@ -1917,7 +1917,7 @@ fail4:
     RtlZeroMemory(&(*BlkifRing)->SrbQueue, sizeof(LIST_ENTRY));
 
     __RingFree((*BlkifRing)->Path);
-    (*BlkifRing)->Path;
+    (*BlkifRing)->Path = NULL;
     (*BlkifRing)->Index = 0;
     (*BlkifRing)->Ring = NULL;
 
@@ -1957,6 +1957,10 @@ BlkifRingDestroy(
     ASSERT(IsListEmpty(&BlkifRing->ShutdownQueue));
     RtlZeroMemory(&BlkifRing->ShutdownQueue, sizeof(LIST_ENTRY));
 
+    BlkifRing->SrbsQueued = 0;
+    BlkifRing->SrbsCompleted = 0;
+    BlkifRing->SrbsFailed = 0;
+
     __RingFree(BlkifRing->Path);
     BlkifRing->Path = NULL;
     BlkifRing->Index = 0;
-- 
2.51.2.windows.1