Changeset 36982 in vbox for trunk/src/VBox/Runtime

Timestamp:

May 6, 2011 1:46:03 PM (14 years ago)

Author:

vboxsync

Message:

alloc-r0drv.cpp: Fixed bug in RTMemReallocTag when RTR0MEM_STRICT is defined - the case reusing the old block didn't take the fence into account. Fixed fence violation messages (cbReq and cb was mixed so we got the bits after the block instead of the broken fence).

File:

• trunk/src/VBox/Runtime/r0drv/alloc-r0drv.cpp (modified) (4 diffs)

trunk/src/VBox/Runtime/r0drv/alloc-r0drv.cpp

@@ -180 +180 @@
 RTDECL(void *) RTMemReallocTag(void *pvOld, size_t cbNew, const char *pszTag) RT_NO_THROW
 {
-    if (!cbNew)
+    /* Free. */
+    if (!cbNew && pvOld)
+    {
         RTMemFree(pvOld);
-    else if (!pvOld)
+        return NULL;
+    }
+
+    /* Alloc. */
+    if (!pvOld)
         return RTMemAllocTag(cbNew, pszTag);
-    else
-    {
-        PRTMEMHDR pHdrOld = (PRTMEMHDR)pvOld - 1;
-        RT_ASSERT_PREEMPTIBLE();
-
-        if (pHdrOld->u32Magic == RTMEMHDR_MAGIC)
+
+    /*
+     * Realloc.
+     */
+    PRTMEMHDR pHdrOld = (PRTMEMHDR)pvOld - 1;
+    RT_ASSERT_PREEMPTIBLE();
+
+    if (pHdrOld->u32Magic == RTMEMHDR_MAGIC)
+    {
+        PRTMEMHDR pHdrNew;
+
+        /* If there is sufficient space in the old block and we don't cause
+           substantial internal fragmentation, reuse the old block. */
+        if (   pHdrOld->cb >= cbNew + RTR0MEM_FENCE_EXTRA
+            && pHdrOld->cb - (cbNew + RTR0MEM_FENCE_EXTRA) <= 128)
         {
-            PRTMEMHDR pHdrNew;
-            if (pHdrOld->cb >= cbNew && pHdrOld->cb - cbNew <= 128)
-                return pvOld;
-            pHdrNew = rtR0MemAlloc(cbNew + RTR0MEM_FENCE_EXTRA, 0);
-            if (pHdrNew)
-            {
-                size_t cbCopy = RT_MIN(pHdrOld->cb, pHdrNew->cb);
-                memcpy(pHdrNew + 1, pvOld, cbCopy);
-#ifdef RTR0MEM_STRICT
-                pHdrNew->cbReq = (uint32_t)cbNew; Assert(pHdrNew->cbReq == cbNew);
-                memcpy((uint8_t *)(pHdrNew + 1) + cbNew, &g_abFence[0], RTR0MEM_FENCE_EXTRA);
-                AssertReleaseMsg(!memcmp((uint8_t *)(pHdrOld + 1) + pHdrOld->cbReq, &g_abFence[0], RTR0MEM_FENCE_EXTRA),
-                                 ("pHdr=%p pvOld=%p cb=%zu cbNew=%zu\n"
-                                  "fence:    %.*Rhxs\n"
-                                  "expected: %.*Rhxs\n",
-                                  pHdrOld, pvOld, pHdrOld->cb, cbNew,
-                                  RTR0MEM_FENCE_EXTRA, (uint8_t *)(pHdrOld + 1) + pHdrOld->cb,
-                                  RTR0MEM_FENCE_EXTRA, &g_abFence[0]));
-#endif
-                rtR0MemFree(pHdrOld);
-                return pHdrNew + 1;
-            }
+            pHdrOld->cbReq = (uint32_t)cbNew; Assert(pHdrOld->cbReq == cbNew);
+#ifdef RTR0MEM_STRICT
+            memcpy((uint8_t *)(pHdrOld + 1) + cbNew, &g_abFence[0], RTR0MEM_FENCE_EXTRA);
+#endif
+            return pvOld;
         }
-        else
-            AssertMsgFailed(("pHdrOld->u32Magic=%RX32 pvOld=%p cbNew=%#zx\n", pHdrOld->u32Magic, pvOld, cbNew));
-    }
+
+        /* Allocate a new block and copy over the content. */
+        pHdrNew = rtR0MemAlloc(cbNew + RTR0MEM_FENCE_EXTRA, 0);
+        if (pHdrNew)
+        {
+            size_t cbCopy = RT_MIN(pHdrOld->cb, pHdrNew->cb);
+            memcpy(pHdrNew + 1, pvOld, cbCopy);
+#ifdef RTR0MEM_STRICT
+            pHdrNew->cbReq = (uint32_t)cbNew; Assert(pHdrNew->cbReq == cbNew);
+            memcpy((uint8_t *)(pHdrNew + 1) + cbNew, &g_abFence[0], RTR0MEM_FENCE_EXTRA);
+            AssertReleaseMsg(!memcmp((uint8_t *)(pHdrOld + 1) + pHdrOld->cbReq, &g_abFence[0], RTR0MEM_FENCE_EXTRA),
+                             ("pHdr=%p pvOld=%p cbReq=%u cb=%u cbNew=%zu fFlags=%#x\n"
+                              "fence:    %.*Rhxs\n"
+                              "expected: %.*Rhxs\n",
+                              pHdrOld, pvOld, pHdrOld->cbReq, pHdrOld->cb, cbNew, pHdrOld->fFlags,
+                              RTR0MEM_FENCE_EXTRA, (uint8_t *)(pHdrOld + 1) + pHdrOld->cbReq,
+                              RTR0MEM_FENCE_EXTRA, &g_abFence[0]));
+#endif
+            rtR0MemFree(pHdrOld);
+            return pHdrNew + 1;
+        }
+    }
+    else
+        AssertMsgFailed(("pHdrOld->u32Magic=%RX32 pvOld=%p cbNew=%#zx\n", pHdrOld->u32Magic, pvOld, cbNew));
 
     return NULL;
@@ -237 +256 @@
 #ifdef RTR0MEM_STRICT
         AssertReleaseMsg(!memcmp((uint8_t *)(pHdr + 1) + pHdr->cbReq, &g_abFence[0], RTR0MEM_FENCE_EXTRA),
-                         ("pHdr=%p pv=%p cb=%zu\n"
+                         ("pHdr=%p pv=%p cbReq=%u cb=%u fFlags=%#x\n"
                           "fence:    %.*Rhxs\n"
                           "expected: %.*Rhxs\n",
-                          pHdr, pv, pHdr->cb,
-                          RTR0MEM_FENCE_EXTRA, (uint8_t *)(pHdr + 1) + pHdr->cb,
+                          pHdr, pv, pHdr->cbReq, pHdr->cb, pHdr->fFlags,
+                          RTR0MEM_FENCE_EXTRA, (uint8_t *)(pHdr + 1) + pHdr->cbReq,
                           RTR0MEM_FENCE_EXTRA, &g_abFence[0]));
 #endif
@@ -292 +311 @@
 #ifdef RTR0MEM_STRICT
         AssertReleaseMsg(!memcmp((uint8_t *)(pHdr + 1) + pHdr->cbReq, &g_abFence[0], RTR0MEM_FENCE_EXTRA),
-                         ("pHdr=%p pv=%p cb=%zu\n"
+                         ("pHdr=%p pv=%p cbReq=%u cb=%u fFlags=%#x\n"
                           "fence:    %.*Rhxs\n"
                           "expected: %.*Rhxs\n",
-                          pHdr, pv, pHdr->cb,
-                          RTR0MEM_FENCE_EXTRA, (uint8_t *)(pHdr + 1) + pHdr->cb,
+                          pHdr, pv, pHdr->cbReq, pHdr->cb, pHdr->fFlags,
+                          RTR0MEM_FENCE_EXTRA, (uint8_t *)(pHdr + 1) + pHdr->cbReq,
                           RTR0MEM_FENCE_EXTRA, &g_abFence[0]));
 #endif
@@ -393 +412 @@
 #ifdef RTR0MEM_STRICT
         AssertReleaseMsg(!memcmp((uint8_t *)(pHdr + 1) + pHdr->cbReq, &g_abFence[0], RTR0MEM_FENCE_EXTRA),
-                         ("pHdr=%p pv=%p cb=%zu\n"
+                         ("pHdr=%p pv=%p cbReq=%u cb=%u fFlags=%#x\n"
                           "fence:    %.*Rhxs\n"
                           "expected: %.*Rhxs\n",
-                          pHdr, pv, pHdr->cb,
-                          RTR0MEM_FENCE_EXTRA, (uint8_t *)(pHdr + 1) + pHdr->cb,
+                          pHdr, pv, pHdr->cbReq, pHdr->cb, pHdr->fFlags,
+                          RTR0MEM_FENCE_EXTRA, (uint8_t *)(pHdr + 1) + pHdr->cbReq,
                           RTR0MEM_FENCE_EXTRA, &g_abFence[0]));
 #endif