Changeset 64584 in vbox for trunk/src/VBox/HostDrivers/Support

Timestamp:

Nov 4, 2016 7:08:09 PM (8 years ago)

Author:

vboxsync

Message:

SUPDrv-dtrace.cpp: the dtrace_register/invalidate/unregister APIs could perhaps mess up the AC flag, so safe+restore flags.

File:

• trunk/src/VBox/HostDrivers/Support/SUPDrv-dtrace.cpp (modified) (9 diffs)

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

@@ -108 +108 @@
 
 
+/** @name Macros for preserving EFLAGS.AC (despair / paranoid)
+ * @remarks We have to restore it unconditionally on darwin.
+ * @{ */
+#if defined(RT_OS_DARWIN) \
+ || (    defined(RT_OS_LINUX) \
+     && (defined(CONFIG_X86_SMAP) || defined(RT_STRICT) || defined(IPRT_WITH_EFLAGS_AC_PRESERVING) ) )
+# include <iprt/asm-amd64-x86.h>
+# include <iprt/x86.h>
+# define SUPDRV_SAVE_EFL_AC()          RTCCUINTREG const fSavedEfl = ASMGetFlags();
+# define SUPDRV_RESTORE_EFL_AC()       ASMSetFlags(fSavedEfl)
+# define SUPDRV_RESTORE_EFL_ONLY_AC()  ASMChangeFlags(~X86_EFL_AC, fSavedEfl & X86_EFL_AC)
+#else
+# define SUPDRV_SAVE_EFL_AC()          do { } while (0)
+# define SUPDRV_RESTORE_EFL_AC()       do { } while (0)
+# define SUPDRV_RESTORE_EFL_ONLY_AC()  do { } while (0)
+#endif
+/** @} */
+
+
 /*********************************************************************************************************************************
 *   Structures and Typedefs                                                                                                      *
@@ -773 +792 @@
     AssertPtrReturnVoid(pVtgProbeLoc->pszFunction);
 
+    SUPDRV_SAVE_EFL_AC();
     VBDT_SETUP_STACK_DATA(kVBoxDtCaller_ProbeFireKernel);
 
@@ -816 +836 @@
 
     VBDT_CLEAR_STACK_DATA();
+    SUPDRV_RESTORE_EFL_AC();
     LOG_DTRACE(("%s: returns\n", __FUNCTION__));
 }
@@ -831 +852 @@
     AssertPtrReturnVoid(pVtgHdr);
 
+    SUPDRV_SAVE_EFL_AC();
     VBDT_SETUP_STACK_DATA(kVBoxDtCaller_ProbeFireUser);
 
@@ -900 +922 @@
 
     VBDT_CLEAR_STACK_DATA();
+    SUPDRV_RESTORE_EFL_AC();
     LOG_DTRACE(("%s: returns\n", __FUNCTION__));
 }
@@ -958 +981 @@
              have to point it to pCore->TracerData.DTrace.idProvider. */
     AssertCompile(sizeof(dtrace_provider_id_t) == sizeof(pCore->TracerData.DTrace.idProvider));
+    SUPDRV_SAVE_EFL_AC();
     int rc = dtrace_register(pCore->pszName,
                              &DtAttrs,
@@ -965 +989 @@
                              pCore,
                              &pCore->TracerData.DTrace.idProvider);
+    SUPDRV_RESTORE_EFL_AC();
     if (!rc)
     {
@@ -992 +1017 @@
     AssertPtrReturn(idProvider, VERR_INTERNAL_ERROR_3);
 
+    SUPDRV_SAVE_EFL_AC();
     dtrace_invalidate(idProvider);
     int rc = dtrace_unregister(idProvider);
+    SUPDRV_RESTORE_EFL_AC();
     if (!rc)
     {
@@ -1022 +1049 @@
     Assert(pCore->TracerData.DTrace.fZombie);
 
+    SUPDRV_SAVE_EFL_AC();
     int rc = dtrace_unregister(idProvider);
+    SUPDRV_RESTORE_EFL_AC();
     if (!rc)
     {