Changeset 71602 in vbox

Timestamp:

Apr 1, 2018 4:44:41 PM (6 years ago)

Author:

vboxsync

Message:

iprt/cdefs.h: Introduced a couple of more macros for paranoid handling untrusted data.

Location:

trunk/include

Files:

• VBox/Graphics/VBoxVideo.h (modified) (1 diff)
• iprt/cdefs.h (modified) (4 diffs)

trunk/include/VBox/Graphics/VBoxVideo.h

@@ -1391 +1391 @@
     VBOXVDMA_CTL_TYPE_DISABLE,
     VBOXVDMA_CTL_TYPE_FLUSH,
-    VBOXVDMA_CTL_TYPE_WATCHDOG
+    VBOXVDMA_CTL_TYPE_WATCHDOG,
+    VBOXVDMA_CTL_TYPE_END
 } VBOXVDMA_CTL_TYPE;
 

trunk/include/iprt/cdefs.h

@@ -1583 +1583 @@
  * This is more than just documentation as it specifies the 'volatile' keyword,
  * because the guest could modify the data at any time. */
-#define RT_UNTRUSTED_VOLATILE_USER      volatile
+#define RT_UNTRUSTED_VOLATILE_USER              volatile
 
 /** @def RT_UNTRUSTED_GUEST
@@ -1593 +1593 @@
  * This is more than just documentation as it specifies the 'volatile' keyword,
  * because the guest could modify the data at any time. */
-#define RT_UNTRUSTED_VOLATILE_GUEST     volatile
+#define RT_UNTRUSTED_VOLATILE_GUEST             volatile
 
 /** @def RT_UNTRUSTED_HOST
@@ -1603 +1603 @@
  * This is more than just documentation as it specifies the 'volatile' keyword,
  * because the host could modify the data at any time. */
-#define RT_UNTRUSTED_VOLATILE_HOST      volatile
+#define RT_UNTRUSTED_VOLATILE_HOST              volatile
 
 /** @def RT_UNTRUSTED_HSTGST
@@ -1613 +1613 @@
  * This is more than just documentation as it specifies the 'volatile' keyword,
  * because the host could modify the data at any time. */
-#define RT_UNTRUSTED_VOLATILE_HSTGST    volatile
+#define RT_UNTRUSTED_VOLATILE_HSTGST            volatile
+/** @} */
+
+/** @name Fences for use when handling untrusted data.
+ * @{ */
+/** For use after copying untruated volatile data to a non-volatile location.
+ * This translates to a compiler memory barrier and will help ensure that the
+ * compiler uses the non-volatile copy of the data. */
+#define RT_UNTRUSTED_NONVOLATILE_COPY_FENCE()   ASMCompilerBarrier()
+/** For use after finished validating guest input.
+ * What this translates to is architecture dependent.  On intel it will
+ * translate to a CPU load+store fence as well as a compiler memory barrier. */
+#if   defined(RT_ARCH_AMD64)
+# define RT_UNTRUSTED_VALIDATED_FENCE()         do { ASMCompilerBarrier(); ASMMemoryFenceSSE2(); } while (0)
+#elif defined(RT_ARCH_X86)
+# define RT_UNTRUSTED_VALIDATED_FENCE()         do { ASMCompilerBarrier(); ASMMemoryFence(); } while (0)
+#else
+# define RT_UNTRUSTED_VALIDATED_FENCE()         do { ASMCompilerBarrier(); } while (0)
+#endif
 /** @} */