CSAMRC.cpp revision 1e29d016a09a61485fda74f7fca39e171ff5dda8
49b7860084dbba18bc00b29413d6182197f9fe93Robert Mustacchi * CSAM - Guest OS Code Scanning and Analysis Manager - Any Context
75eba5b6d79ed4d2ce3daf7b2806306b6b69a938Robert Mustacchi * Copyright (C) 2006-2013 Oracle Corporation
75eba5b6d79ed4d2ce3daf7b2806306b6b69a938Robert Mustacchi * This file is part of VirtualBox Open Source Edition (OSE), as
75eba5b6d79ed4d2ce3daf7b2806306b6b69a938Robert Mustacchi * available from http://www.virtualbox.org. This file is free software;
75eba5b6d79ed4d2ce3daf7b2806306b6b69a938Robert Mustacchi * you can redistribute it and/or modify it under the terms of the GNU
75eba5b6d79ed4d2ce3daf7b2806306b6b69a938Robert Mustacchi * General Public License (GPL) as published by the Free Software
75eba5b6d79ed4d2ce3daf7b2806306b6b69a938Robert Mustacchi * Foundation, in version 2 as it comes in the "COPYING" file of the
75eba5b6d79ed4d2ce3daf7b2806306b6b69a938Robert Mustacchi * VirtualBox OSE distribution. VirtualBox OSE is distributed in the
75eba5b6d79ed4d2ce3daf7b2806306b6b69a938Robert Mustacchi * hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
75eba5b6d79ed4d2ce3daf7b2806306b6b69a938Robert Mustacchi/*******************************************************************************
75eba5b6d79ed4d2ce3daf7b2806306b6b69a938Robert Mustacchi* Header Files *
75eba5b6d79ed4d2ce3daf7b2806306b6b69a938Robert Mustacchi*******************************************************************************/
75eba5b6d79ed4d2ce3daf7b2806306b6b69a938Robert Mustacchi * \#PF Handler callback for virtual access handler ranges. (CSAM self-modifying
c124a83e09115de88ecccd4f689983f42a1d53bdRobert Mustacchi * code monitor)
75eba5b6d79ed4d2ce3daf7b2806306b6b69a938Robert Mustacchi * Important to realize that a physical page in a range can have aliases, and
75eba5b6d79ed4d2ce3daf7b2806306b6b69a938Robert Mustacchi * for ALL and WRITE handlers these will also trigger.
c124a83e09115de88ecccd4f689983f42a1d53bdRobert Mustacchi * @returns VBox status code (appropriate for GC return).
c124a83e09115de88ecccd4f689983f42a1d53bdRobert Mustacchi * @param pVM Pointer to the VM.
c124a83e09115de88ecccd4f689983f42a1d53bdRobert Mustacchi * @param uErrorCode CPU Error code.
c124a83e09115de88ecccd4f689983f42a1d53bdRobert Mustacchi * @param pRegFrame Trap register frame.
c124a83e09115de88ecccd4f689983f42a1d53bdRobert Mustacchi * @param pvFault The fault address (cr2).
c124a83e09115de88ecccd4f689983f42a1d53bdRobert Mustacchi * @param pvRange The base address of the handled virtual range.
c124a83e09115de88ecccd4f689983f42a1d53bdRobert Mustacchi * @param offRange The offset of the access into this range.
c124a83e09115de88ecccd4f689983f42a1d53bdRobert Mustacchi * (If it's a EIP range this is the EIP, if not it's pvFault.)
75eba5b6d79ed4d2ce3daf7b2806306b6b69a938Robert MustacchiVMMRCDECL(int) CSAMGCCodePageWriteHandler(PVM pVM, RTGCUINT uErrorCode, PCPUMCTXCORE pRegFrame, RTGCPTR pvFault, RTGCPTR pvRange, uintptr_t offRange)
75eba5b6d79ed4d2ce3daf7b2806306b6b69a938Robert Mustacchi bool fPatchCode = PATMIsPatchGCAddr(pVM, pRegFrame->eip);
c124a83e09115de88ecccd4f689983f42a1d53bdRobert Mustacchi Assert(pVM->csam.s.cDirtyPages < CSAM_MAX_DIRTY_PAGES);
c124a83e09115de88ecccd4f689983f42a1d53bdRobert Mustacchi /* Flush the recompilers translation block cache as the guest seems to be modifying instructions. */
75eba5b6d79ed4d2ce3daf7b2806306b6b69a938Robert Mustacchi /** When patch code is executing instructions that must complete, then we must *never* interrupt it. */
c124a83e09115de88ecccd4f689983f42a1d53bdRobert Mustacchi Log(("CSAMGCCodePageWriteHandler: fPIF=0 -> stack fault in patch generated code at %08RX32!\n", pRegFrame->eip));
c124a83e09115de88ecccd4f689983f42a1d53bdRobert Mustacchi /** @note there are cases when pages previously used for code are now used for stack; patch generated code will fault (pushf))
75eba5b6d79ed4d2ce3daf7b2806306b6b69a938Robert Mustacchi * Just make the page r/w and continue.
75eba5b6d79ed4d2ce3daf7b2806306b6b69a938Robert Mustacchi * Make this particular page R/W.
75eba5b6d79ed4d2ce3daf7b2806306b6b69a938Robert Mustacchi rc = PGMShwMakePageWritable(pVCpu, pvFault, PGM_MK_PG_IS_WRITE_FAULT);
75eba5b6d79ed4d2ce3daf7b2806306b6b69a938Robert Mustacchi AssertMsgRC(rc, ("PGMShwModifyPage -> rc=%Rrc\n", rc));
75eba5b6d79ed4d2ce3daf7b2806306b6b69a938Robert Mustacchi ASMInvalidatePage((void *)(uintptr_t)pvFault);
75eba5b6d79ed4d2ce3daf7b2806306b6b69a938Robert Mustacchi Log(("CSAMGCCodePageWriteHandler: code page write at %RGv original address %RGv (cpl=%d)\n", pvFault, (RTGCUINTPTR)pvRange + offRange, cpl));
75eba5b6d79ed4d2ce3daf7b2806306b6b69a938Robert Mustacchi /* If user code is modifying one of our monitored pages, then we can safely make it r/w as it's no longer being used for supervisor code. */
c124a83e09115de88ecccd4f689983f42a1d53bdRobert Mustacchi rc = PATMRCHandleWriteToPatchPage(pVM, pRegFrame, (RTRCPTR)((RTRCUINTPTR)pvRange + offRange), 4 /** @todo */);
c124a83e09115de88ecccd4f689983f42a1d53bdRobert Mustacchi STAM_COUNTER_INC(&pVM->csam.s.StatDangerousWrite);
75eba5b6d79ed4d2ce3daf7b2806306b6b69a938Robert Mustacchi VMCPU_FF_SET(pVCpu, VMCPU_FF_CSAM_PENDING_ACTION);
75eba5b6d79ed4d2ce3daf7b2806306b6b69a938Robert Mustacchi /* Note that pvFault might be a different address in case of aliases. So use pvRange + offset instead!. */
75eba5b6d79ed4d2ce3daf7b2806306b6b69a938Robert Mustacchi pVM->csam.s.pvDirtyBasePage[pVM->csam.s.cDirtyPages] = (RTRCPTR)((RTRCUINTPTR)pvRange + offRange);
75eba5b6d79ed4d2ce3daf7b2806306b6b69a938Robert Mustacchi pVM->csam.s.pvDirtyFaultPage[pVM->csam.s.cDirtyPages] = (RTRCPTR)((RTRCUINTPTR)pvRange + offRange);
75eba5b6d79ed4d2ce3daf7b2806306b6b69a938Robert Mustacchi if (++pVM->csam.s.cDirtyPages == CSAM_MAX_DIRTY_PAGES)
75eba5b6d79ed4d2ce3daf7b2806306b6b69a938Robert Mustacchi * Make this particular page R/W. The VM_FF_CSAM_FLUSH_DIRTY_PAGE handler will reset it to readonly again.
75eba5b6d79ed4d2ce3daf7b2806306b6b69a938Robert Mustacchi Log(("CSAMGCCodePageWriteHandler: enabled r/w for page %RGv\n", pvFault));
c124a83e09115de88ecccd4f689983f42a1d53bdRobert Mustacchi rc = PGMShwMakePageWritable(pVCpu, pvFault, PGM_MK_PG_IS_WRITE_FAULT);
c124a83e09115de88ecccd4f689983f42a1d53bdRobert Mustacchi AssertMsgRC(rc, ("PGMShwModifyPage -> rc=%Rrc\n", rc));
c124a83e09115de88ecccd4f689983f42a1d53bdRobert Mustacchi ASMInvalidatePage((void *)(uintptr_t)pvFault);