Changeset 57229 in vbox for trunk/src/VBox/HostDrivers/Support/darwin

Timestamp:

Aug 6, 2015 11:34:04 PM (10 years ago)

Author:

vboxsync

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

101982

Message:

SUPDrv,VMMR0: Added SUPR0BadContext for reporting AC=0 and (on darwin with VBOX_WITH_EFLAGS_AC_SET_IN_VBOXDRV defined) refuse further I/O control calls. That way we'll sit up and pay attention, hopefully. VBOX_WITH_EFLAGS_AC_SET_IN_VBOXDRV is currently enabled for all non-release builds (odd build numbers), and we check EFLAGS.AC at the end of each ioctrl call.

File:

• trunk/src/VBox/HostDrivers/Support/darwin/SUPDrv-darwin.cpp (modified) (5 diffs)

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

@@ -79 +79 @@
 #endif
 
-/* Temporary debugging. */
+/* The following macros are duplicated in the-darwin-kernel.h. */
+#define IPRT_DARWIN_SAVE_EFL_AC()           RTCCUINTREG const fSavedEfl = ASMGetFlags();
+#define IPRT_DARWIN_RESTORE_EFL_AC()        ASMSetFlags(fSavedEfl)
+#define IPRT_DARWIN_RESTORE_EFL_ONLY_AC()   ASMChangeFlags(~X86_EFL_AC, fSavedEfl & X86_EFL_AC)
+
+
+/* Temporary debugging - very temporary... */
 #define VBOX_PROC_SELFNAME_LEN  (20)
-#define VBOX_RETRIEVE_CUR_PROC_NAME(_name)    char _name[VBOX_PROC_SELFNAME_LEN]; \
-                                              proc_selfname(pszProcName, VBOX_PROC_SELFNAME_LEN)
+#define VBOX_RETRIEVE_CUR_PROC_NAME(_name)  char _name[VBOX_PROC_SELFNAME_LEN]; \
+                                            proc_selfname(pszProcName, VBOX_PROC_SELFNAME_LEN)
 
 
@@ -586 +592 @@
     PSUPDRVSESSION      pSession;
 
+#ifdef VBOX_WITH_EFLAGS_AC_SET_IN_VBOXDRV
+    /*
+     * Refuse all I/O control calls if we've ever detected EFLAGS.AC being cleared.
+     *
+     * This isn't a problem, as there is absolutely nothing in the kernel context that
+     * depend on user context triggering cleanups.  That would be pretty wild, right?
+     */
+    if (RT_UNLIKELY(g_DevExt.cBadContextCalls > 0))
+    {
+        SUPR0Printf("VBoxDrvDarwinIOCtl: EFLAGS.AC=0 detected %u times, refusing all I/O controls!\n", g_DevExt.cBadContextCalls);
+        return EDEVERR;
+    }
+#endif
+
     /*
      * Find the session.
@@ -651 +671 @@
 #if defined(VBOX_STRICT) || defined(VBOX_WITH_EFLAGS_AC_SET_IN_VBOXDRV)
     if (RT_UNLIKELY(!(ASMGetFlags() & X86_EFL_AC)))
-        SUPR0Printf("VBoxDrvDarwinIOCtlSMAP: someone cleared AC handling iCmd=%#lx\n", iCmd);
+        supdrvBadContext(&g_DevExt, "SUPDrv-darwin.cpp",  __LINE__, "VBoxDrvDarwinIOCtlSMAP");
 #endif
     ASMSetFlags(fSavedEfl);
@@ -1435 +1455 @@
 RTDECL(int) SUPR0Printf(const char *pszFormat, ...)
 {
+    IPRT_DARWIN_SAVE_EFL_AC();
     va_list     va;
     char        szMsg[512];
@@ -1444 +1465 @@
 
     printf("%s", szMsg);
+
+    IPRT_DARWIN_RESTORE_EFL_AC();
     return 0;
 }