Changeset 99421 in vbox

Timestamp:

Apr 17, 2023 2:38:06 PM (2 years ago)

Author:

vboxsync

svn:sync-xref-src-repo-rev:

156875

Message:

SUPDrv: Move SUPDRV_MEMCPY to SUPDrvInternal.h and try explain why and when to use. bugref:10209 ticketref:21410

Location:

trunk/src/VBox/HostDrivers/Support

Files:

• SUPDrv.cpp (modified) (2 diffs)
• SUPDrvInternal.h (modified) (2 diffs)

trunk/src/VBox/HostDrivers/Support/SUPDrv.cpp

@@ -84 +84 @@
 # define VBOXDRV_IOCTL_ENTRY(pvSession, uIOCtl, pvReqHdr) do { } while (0)
 # define VBOXDRV_IOCTL_RETURN(pvSession, uIOCtl, pvReqHdr, rcRet, rcReq) do { } while (0)
-#endif
-
-#if defined(RT_OS_LINUX)
-/* In Linux 5.18-rc1, memcpy became a wrapper which does fortify checks
- * before triggering __underlying_memcpy() call. We do not pass these checks here,
- * so bypass them for now.  */
-# if RTLNX_VER_MIN(5,18,0) && !defined(__NO_FORTIFY) && defined(__OPTIMIZE__) && defined(CONFIG_FORTIFY_SOURCE)
-#  define SUPDRV_MEMCPY __underlying_memcpy
-# else
-# define SUPDRV_MEMCPY  memcpy
-# endif
-#else
-# define SUPDRV_MEMCPY  memcpy
 #endif
 
@@ -1778 +1765 @@
             /* execute */
             pReq->u.Out.cFunctions = RT_ELEMENTS(g_aFunctions);
-            SUPDRV_MEMCPY(&pReq->u.Out.aFunctions[0], g_aFunctions, sizeof(g_aFunctions));
+            SUPDRV_UNFORTIFIED_MEMCPY(&pReq->u.Out.aFunctions[0], g_aFunctions, sizeof(g_aFunctions));
             pReq->Hdr.rc = VINF_SUCCESS;
             return 0;

trunk/src/VBox/HostDrivers/Support/SUPDrvInternal.h

@@ -243 +243 @@
 #       endif
 #   endif
+#   if RTLNX_VER_MIN(5,18,0) && !defined(__NO_FORTIFY) && defined(__OPTIMIZE__) && defined(CONFIG_FORTIFY_SOURCE)
+#    define SUPDRV_UNFORTIFIED_MEMCPY __underlying_memcpy
+#   endif
 #   define SUPR0_EXPORT_SYMBOL(a_Name) EXPORT_SYMBOL(a_Name)
 
@@ -372 +375 @@
  * @todo Test on servers with many CPUs and sockets. */
 # define SUPDRV_USE_TSC_DELTA_THREAD
+#endif
+
+/** @def SUPDRV_UNFORTIFIED_MEMCPY
+ * Use when copying to variable length structures, it prevents a fortified 
+ * memcpy (linux 5.18+) from complaining about "field-spanning writes". 
+ *  
+ * @see @ticketref{21410}, @bugref{10209}
+ */
+#if !defined(SUPDRV_UNFORTIFIED_MEMCPY) || defined(DOXYGEN_RUNNING) /* (Already defined above if fortified.) */
+# define SUPDRV_UNFORTIFIED_MEMCPY memcpy
 #endif