Improve auditing in CACHE and GNTTAB interfaces

Add 'Get' and 'Put' counters to CACHEs which can then be checked for
equality at destruction time to make sure all objects have been returned.
Also add a list of GNTTAB caches so that the code can BUG on any
outstanding caches at Release.

Signed-off-by: Paul Durrant <paul.durrant@citrix.com>

diff --git a/src/xenbus/cache.c b/src/xenbus/cache.c
index ba7dcdfa94884cd5d7a9d00f066ec378bf302be6..83993ca2f53dac954ea3ea8e832404a55217cd62 100644 (file)
--- a/src/xenbus/cache.c
+++ b/src/xenbus/cache.c
@@ -79,8 +79,10 @@ struct _XENBUS_CACHE {
     VOID                    (*ReleaseLock)(PVOID);
     PVOID                   Argument;
     LIST_ENTRY              GetList;
+    LONG                    GetCount;
     PLIST_ENTRY             PutList;
-    LONG                    ObjectCount;
+    LONG                    PutCount;
+    LONG                    ListCount;
     PXENBUS_CACHE_MAGAZINE  Magazine;
     ULONG                   MagazineCount;
     XENBUS_CACHE_FIST       FIST;
@@ -225,7 +227,7 @@ CacheGetObjectFromList(
     KIRQL                       Irql = PASSIVE_LEVEL;
     NTSTATUS                    status;
 
-    Count = InterlockedDecrement(&Cache->ObjectCount);
+    Count = InterlockedDecrement(&Cache->ListCount);
 
     status = STATUS_NO_MEMORY;
     if (Count < 0)
@@ -255,7 +257,7 @@ CacheGetObjectFromList(
     return Object;
 
 fail1:
-    (VOID) InterlockedIncrement(&Cache->ObjectCount);
+    (VOID) InterlockedIncrement(&Cache->ListCount);
 
     return NULL;    
 }
@@ -294,7 +296,7 @@ CachePutObjectToList(
 
     KeMemoryBarrier();
 
-    (VOID) InterlockedIncrement(&Cache->ObjectCount);
+    (VOID) InterlockedIncrement(&Cache->ListCount);
 }
 
 static PVOID
@@ -305,6 +307,7 @@ CacheGetObjectFromMagazine(
 {
     PXENBUS_CACHE_MAGAZINE  Magazine;
 
+    ASSERT3U(Index, <, Cache->MagazineCount);
     Magazine = &Cache->Magazine[Index];
 
     for (Index = 0; Index < XENBUS_CACHE_MAGAZINE_SLOTS; Index++) {
@@ -330,6 +333,7 @@ CachePutObjectToMagazine(
 {
     PXENBUS_CACHE_MAGAZINE  Magazine;
 
+    ASSERT3U(Index, <, Cache->MagazineCount);
     Magazine = &Cache->Magazine[Index];
 
     for (Index = 0; Index < XENBUS_CACHE_MAGAZINE_SLOTS; Index++) {
@@ -385,6 +389,8 @@ CacheGet(
 done:
     KeLowerIrql(Irql);
 
+    (VOID) InterlockedIncrement(&Cache->GetCount);
+
     return Object;
 }
 
@@ -401,6 +407,8 @@ CachePut(
 
     UNREFERENCED_PARAMETER(Interface);
 
+    (VOID) InterlockedIncrement(&Cache->PutCount);
+
     KeRaiseIrql(DISPATCH_LEVEL, &Irql);
     Index = KeGetCurrentProcessorNumberEx(NULL);
 
@@ -679,17 +687,22 @@ CacheDestroy(
 
     RtlZeroMemory(&Cache->ListEntry, sizeof (LIST_ENTRY));
 
+    ASSERT3U(Cache->PutCount, ==, Cache->GetCount);
+    Cache->PutCount = 0;
+    Cache->GetCount = 0;
+
     Cache->Reservation = 0;
     CacheFlushMagazines(Cache);
-    CacheSpill(Cache, Cache->ObjectCount);
-
-    ASSERT3U(Cache->ObjectCount, ==, 0);
 
     ASSERT(IsZeroMemory(Cache->Magazine, sizeof (XENBUS_CACHE_MAGAZINE) * Cache->MagazineCount));
     __CacheFree(Cache->Magazine);
     Cache->Magazine = NULL;
     Cache->MagazineCount = 0;
 
+    CacheSpill(Cache, Cache->ListCount);
+    ASSERT3U(Cache->ListCount, ==, 0);
+
+    ASSERT(IsListEmpty(&Cache->GetList));
     RtlZeroMemory(&Cache->GetList, sizeof (LIST_ENTRY));
 
     RtlZeroMemory(&Cache->FIST, sizeof (XENBUS_CACHE_FIST));
@@ -737,7 +750,7 @@ CacheDebugCallback(
                          &Context->DebugInterface,
                          "- %s: Count = %d (Reservation = %d)\n",
                          Cache->Name,
-                         Cache->ObjectCount,
+                         Cache->ListCount,
                          Cache->Reservation);
         }
     }
@@ -793,7 +806,7 @@ CacheMonitor(
 
             Cache = CONTAINING_RECORD(ListEntry, XENBUS_CACHE, ListEntry);
 
-            Count = Cache->ObjectCount;
+            Count = Cache->ListCount;
 
             if (Count < Cache->Reservation)
                 CacheFill(Cache, Cache->Reservation - Count);

diff --git a/src/xenbus/gnttab.c b/src/xenbus/gnttab.c
index 39120287c8be55f0aa54c4e10bdb91428dba93f5..165e38f1f155edee1b87f40eeea4c15ddac2b1d4 100644 (file)
--- a/src/xenbus/gnttab.c
+++ b/src/xenbus/gnttab.c
@@ -53,8 +53,9 @@
 #define MAXNAMELEN  128
 
 struct _XENBUS_GNTTAB_CACHE {
-    PXENBUS_GNTTAB_CONTEXT  Context;
+    LIST_ENTRY              ListEntry;
     CHAR                    Name[MAXNAMELEN];
+    PXENBUS_GNTTAB_CONTEXT  Context;
     VOID                    (*AcquireLock)(PVOID);
     VOID                    (*ReleaseLock)(PVOID);
     PVOID                   Argument;
@@ -81,6 +82,7 @@ struct _XENBUS_GNTTAB_CONTEXT {
     PXENBUS_SUSPEND_CALLBACK    SuspendCallbackEarly;
     XENBUS_DEBUG_INTERFACE      DebugInterface;
     PXENBUS_DEBUG_CALLBACK      DebugCallback;
+    LIST_ENTRY                  List;
 };
 
 #define XENBUS_GNTTAB_TAG   'TTNG'
@@ -321,6 +323,7 @@ GnttabCreateCache(
     )
 {
     PXENBUS_GNTTAB_CONTEXT      Context = Interface->Context;
+    KIRQL                       Irql;
     NTSTATUS                    status;
 
     *Cache = __GnttabAllocate(sizeof (XENBUS_GNTTAB_CACHE));
@@ -356,6 +359,10 @@ GnttabCreateCache(
     if (!NT_SUCCESS(status))
         goto fail3;
 
+    KeAcquireSpinLock(&Context->Lock, &Irql);
+    InsertTailList(&Context->List, &(*Cache)->ListEntry);
+    KeReleaseSpinLock(&Context->Lock, Irql);
+
     return STATUS_SUCCESS;
 
 fail3:
@@ -388,6 +395,13 @@ GnttabDestroyCache(
     )
 {
     PXENBUS_GNTTAB_CONTEXT      Context = Interface->Context;
+    KIRQL                       Irql;
+
+    KeAcquireSpinLock(&Context->Lock, &Irql);
+    RemoveEntryList(&Cache->ListEntry);
+    KeReleaseSpinLock(&Context->Lock, Irql);
+
+    RtlZeroMemory(&Cache->ListEntry, sizeof (LIST_ENTRY));
 
     XENBUS_CACHE(Destroy,
                  &Context->CacheInterface,
@@ -717,6 +731,9 @@ GnttabRelease(
 
     Trace("====>\n");
 
+    if (!IsListEmpty(&Context->List))
+        BUG("OUTSTANDING CACHES");
+
     XENBUS_DEBUG(Deregister,
                  &Context->DebugInterface,
                  Context->DebugCallback);
@@ -816,6 +833,7 @@ GnttabInitialize(
     ASSERT(NT_SUCCESS(status));
     ASSERT((*Context)->DebugInterface.Interface.Context != NULL);
 
+    InitializeListHead(&(*Context)->List);
     KeInitializeSpinLock(&(*Context)->Lock);
 
     (*Context)->Fdo = Fdo;
@@ -878,6 +896,7 @@ GnttabTeardown(
     Context->Fdo = NULL;
 
     RtlZeroMemory(&Context->Lock, sizeof (KSPIN_LOCK));
+    RtlZeroMemory(&Context->List, sizeof (LIST_ENTRY));
 
     RtlZeroMemory(&Context->DebugInterface,
                   sizeof (XENBUS_DEBUG_INTERFACE));