Changeset 67136 in vbox for trunk/src/VBox/HostDrivers/Support

Timestamp:

May 30, 2017 7:58:21 AM (8 years ago)

Author:

vboxsync

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

115808

Message:

HostDrivers/Support, VMM: bugref:8864: On Linux 4.12 the GDT is mapped read-only. The writable-mapped GDT is available and is used for clearing the TSS BUSY descriptor bit and for LTR.

Location:

trunk/src/VBox/HostDrivers/Support

Files:

• SUPDrv.cpp (modified) (2 diffs)
• SUPDrvInternal.h (modified) (1 diff)
• linux/SUPDrv-linux.c (modified) (3 diffs)

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

@@ -199 +199 @@
     { "SUPR0SuspendVTxOnCpu",                   (void *)(uintptr_t)SUPR0SuspendVTxOnCpu },
     { "SUPR0ResumeVTxOnCpu",                    (void *)(uintptr_t)SUPR0ResumeVTxOnCpu },
+    { "SUPR0GetCurrentGdtRw",                   (void *)(uintptr_t)SUPR0GetCurrentGdtRw },
     { "SUPR0GetKernelFeatures",                 (void *)(uintptr_t)SUPR0GetKernelFeatures },
     { "SUPR0GetPagingMode",                     (void *)(uintptr_t)SUPR0GetPagingMode },
@@ -3877 +3878 @@
 
 
+SUPR0DECL(int) SUPR0GetCurrentGdtRw(RTHCUINTPTR *pGdtRw)
+{
+#ifdef RT_OS_LINUX
+    return supdrvOSetCurrentGdtRw(pGdtRw);
+#else
+    return VERR_NOT_IMPLEMENTED;
+#endif
+}
+
+
 /**
  * Checks if Intel VT-x feature is usable on this CPU.

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

@@ -842 +842 @@
 bool VBOXCALL   supdrvOSSuspendVTxOnCpu(void);
 void VBOXCALL   supdrvOSResumeVTxOnCpu(bool fSuspended);
+int  VBOXCALL   supdrvOSetCurrentGdtRw(RTHCUINTPTR *pGdtRw);
 
 /**

trunk/src/VBox/HostDrivers/Support/linux/SUPDrv-linux.c

@@ -61 +61 @@
 # include <asm/msr.h>
 #endif
+
+#include <asm/desc.h>
 
 #include <iprt/asm-amd64-x86.h>
@@ -1401 +1403 @@
     fFlags |= SUPKERNELFEATURES_GDT_READ_ONLY;
 #endif
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 12, 0)
+    fFlags |= SUPKERNELFEATURES_GDT_NEED_WRITABLE;
+#endif
 #if defined(VBOX_STRICT) || defined(VBOX_WITH_EFLAGS_AC_SET_IN_VBOXDRV)
     fFlags |= SUPKERNELFEATURES_SMAP;
@@ -1411 +1416 @@
 
 
+int supdrvOSetCurrentGdtRw(RTHCUINTPTR *pGdtRw)
+{
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 12, 0)
+    *pGdtRw = (RTHCUINTPTR)get_current_gdt_rw();
+    return VINF_SUCCESS;
+#else
+    return VERR_NOT_IMPLEMENTED;
+#endif
+}
+
+
 module_init(VBoxDrvLinuxInit);
 module_exit(VBoxDrvLinuxUnload);