/* $Id: PGMDbg.cpp 28800 2010-04-27 08:22:32Z vboxsync $ */ /** @file * PGM - Page Manager and Monitor - Debugger & Debugging APIs. */ /* * Copyright (C) 2006-2007 Oracle Corporation * * This file is part of VirtualBox Open Source Edition (OSE), as * available from http://www.virtualbox.org. This file is free software; * you can redistribute it and/or modify it under the terms of the GNU * General Public License (GPL) as published by the Free Software * Foundation, in version 2 as it comes in the "COPYING" file of the * VirtualBox OSE distribution. VirtualBox OSE is distributed in the * hope that it will be useful, but WITHOUT ANY WARRANTY of any kind. */ /******************************************************************************* * Header Files * *******************************************************************************/ #define LOG_GROUP LOG_GROUP_PGM #include #include #include "PGMInternal.h" #include #include "PGMInline.h" #include #include #include #include #include #include /******************************************************************************* * Defined Constants And Macros * *******************************************************************************/ /** The max needle size that we will bother searching for * This must not be more than half a page! */ #define MAX_NEEDLE_SIZE 256 /** * Converts a R3 pointer to a GC physical address. * * Only for the debugger. * * @returns VBox status code. * @retval VINF_SUCCESS on success, *pGCPhys is set. * @retval VERR_INVALID_POINTER if the pointer is not within the GC physical memory. * * @param pVM The VM handle. * @param R3Ptr The R3 pointer to convert. * @param pGCPhys Where to store the GC physical address on success. */ VMMR3DECL(int) PGMR3DbgR3Ptr2GCPhys(PVM pVM, RTR3PTR R3Ptr, PRTGCPHYS pGCPhys) { *pGCPhys = NIL_RTGCPHYS; return VERR_NOT_IMPLEMENTED; } /** * Converts a R3 pointer to a HC physical address. * * Only for the debugger. * * @returns VBox status code. * @retval VINF_SUCCESS on success, *pHCPhys is set. * @retval VERR_PGM_PHYS_PAGE_RESERVED it it's a valid GC physical page but has no physical backing. * @retval VERR_INVALID_POINTER if the pointer is not within the GC physical memory. * * @param pVM The VM handle. * @param R3Ptr The R3 pointer to convert. * @param pHCPhys Where to store the HC physical address on success. */ VMMR3DECL(int) PGMR3DbgR3Ptr2HCPhys(PVM pVM, RTR3PTR R3Ptr, PRTHCPHYS pHCPhys) { *pHCPhys = NIL_RTHCPHYS; return VERR_NOT_IMPLEMENTED; } /** * Converts a HC physical address to a GC physical address. * * Only for the debugger. * * @returns VBox status code * @retval VINF_SUCCESS on success, *pGCPhys is set. * @retval VERR_INVALID_POINTER if the HC physical address is not within the GC physical memory. * * @param pVM The VM handle. * @param HCPhys The HC physical address to convert. * @param pGCPhys Where to store the GC physical address on success. */ VMMR3DECL(int) PGMR3DbgHCPhys2GCPhys(PVM pVM, RTHCPHYS HCPhys, PRTGCPHYS pGCPhys) { /* * Validate and adjust the input a bit. */ if (HCPhys == NIL_RTHCPHYS) return VERR_INVALID_POINTER; unsigned off = HCPhys & PAGE_OFFSET_MASK; HCPhys &= X86_PTE_PAE_PG_MASK; if (HCPhys == 0) return VERR_INVALID_POINTER; for (PPGMRAMRANGE pRam = pVM->pgm.s.CTX_SUFF(pRamRanges); pRam; pRam = pRam->CTX_SUFF(pNext)) { uint32_t iPage = pRam->cb >> PAGE_SHIFT; while (iPage-- > 0) if (PGM_PAGE_GET_HCPHYS(&pRam->aPages[iPage]) == HCPhys) { *pGCPhys = pRam->GCPhys + (iPage << PAGE_SHIFT) + off; return VINF_SUCCESS; } } return VERR_INVALID_POINTER; } /** * Read physical memory API for the debugger, similar to * PGMPhysSimpleReadGCPhys. * * @returns VBox status code. * * @param pVM The VM handle. * @param pvDst Where to store what's read. * @param GCPhysDst Where to start reading from. * @param cb The number of bytes to attempt reading. * @param fFlags Flags, MBZ. * @param pcbRead For store the actual number of bytes read, pass NULL if * partial reads are unwanted. * @todo Unused? */ VMMR3DECL(int) PGMR3DbgReadGCPhys(PVM pVM, void *pvDst, RTGCPHYS GCPhysSrc, size_t cb, uint32_t fFlags, size_t *pcbRead) { /* validate */ AssertReturn(!fFlags, VERR_INVALID_PARAMETER); AssertReturn(pVM, VERR_INVALID_PARAMETER); /* try simple first. */ int rc = PGMPhysSimpleReadGCPhys(pVM, pvDst, GCPhysSrc, cb); if (RT_SUCCESS(rc) || !pcbRead) return rc; /* partial read that failed, chop it up in pages. */ *pcbRead = 0; size_t const cbReq = cb; rc = VINF_SUCCESS; while (cb > 0) { size_t cbChunk = PAGE_SIZE; cbChunk -= GCPhysSrc & PAGE_OFFSET_MASK; if (cbChunk > cb) cbChunk = cb; rc = PGMPhysSimpleReadGCPhys(pVM, pvDst, GCPhysSrc, cbChunk); /* advance */ if (RT_FAILURE(rc)) break; *pcbRead += cbChunk; cb -= cbChunk; GCPhysSrc += cbChunk; pvDst = (uint8_t *)pvDst + cbChunk; } return *pcbRead && RT_FAILURE(rc) ? -rc : rc; } /** * Write physical memory API for the debugger, similar to * PGMPhysSimpleWriteGCPhys. * * @returns VBox status code. * * @param pVM The VM handle. * @param GCPhysDst Where to start writing. * @param pvSrc What to write. * @param cb The number of bytes to attempt writing. * @param fFlags Flags, MBZ. * @param pcbWritten For store the actual number of bytes written, pass NULL * if partial writes are unwanted. * @todo Unused? */ VMMR3DECL(int) PGMR3DbgWriteGCPhys(PVM pVM, RTGCPHYS GCPhysDst, const void *pvSrc, size_t cb, uint32_t fFlags, size_t *pcbWritten) { /* validate */ AssertReturn(!fFlags, VERR_INVALID_PARAMETER); AssertReturn(pVM, VERR_INVALID_PARAMETER); /* try simple first. */ int rc = PGMPhysSimpleWriteGCPhys(pVM, GCPhysDst, pvSrc, cb); if (RT_SUCCESS(rc) || !pcbWritten) return rc; /* partial write that failed, chop it up in pages. */ *pcbWritten = 0; rc = VINF_SUCCESS; while (cb > 0) { size_t cbChunk = PAGE_SIZE; cbChunk -= GCPhysDst & PAGE_OFFSET_MASK; if (cbChunk > cb) cbChunk = cb; rc = PGMPhysSimpleWriteGCPhys(pVM, GCPhysDst, pvSrc, cbChunk); /* advance */ if (RT_FAILURE(rc)) break; *pcbWritten += cbChunk; cb -= cbChunk; GCPhysDst += cbChunk; pvSrc = (uint8_t const *)pvSrc + cbChunk; } return *pcbWritten && RT_FAILURE(rc) ? -rc : rc; } /** * Read virtual memory API for the debugger, similar to PGMPhysSimpleReadGCPtr. * * @returns VBox status code. * * @param pVM The VM handle. * @param pvDst Where to store what's read. * @param GCPtrDst Where to start reading from. * @param cb The number of bytes to attempt reading. * @param fFlags Flags, MBZ. * @param pcbRead For store the actual number of bytes read, pass NULL if * partial reads are unwanted. * @todo Unused? */ VMMR3DECL(int) PGMR3DbgReadGCPtr(PVM pVM, void *pvDst, RTGCPTR GCPtrSrc, size_t cb, uint32_t fFlags, size_t *pcbRead) { /* validate */ AssertReturn(!fFlags, VERR_INVALID_PARAMETER); AssertReturn(pVM, VERR_INVALID_PARAMETER); /* @todo SMP support! */ PVMCPU pVCpu = &pVM->aCpus[0]; /** @todo deal with HMA */ /* try simple first. */ int rc = PGMPhysSimpleReadGCPtr(pVCpu, pvDst, GCPtrSrc, cb); if (RT_SUCCESS(rc) || !pcbRead) return rc; /* partial read that failed, chop it up in pages. */ *pcbRead = 0; rc = VINF_SUCCESS; while (cb > 0) { size_t cbChunk = PAGE_SIZE; cbChunk -= GCPtrSrc & PAGE_OFFSET_MASK; if (cbChunk > cb) cbChunk = cb; rc = PGMPhysSimpleReadGCPtr(pVCpu, pvDst, GCPtrSrc, cbChunk); /* advance */ if (RT_FAILURE(rc)) break; *pcbRead += cbChunk; cb -= cbChunk; GCPtrSrc += cbChunk; pvDst = (uint8_t *)pvDst + cbChunk; } return *pcbRead && RT_FAILURE(rc) ? -rc : rc; } /** * Write virtual memory API for the debugger, similar to * PGMPhysSimpleWriteGCPtr. * * @returns VBox status code. * * @param pVM The VM handle. * @param GCPtrDst Where to start writing. * @param pvSrc What to write. * @param cb The number of bytes to attempt writing. * @param fFlags Flags, MBZ. * @param pcbWritten For store the actual number of bytes written, pass NULL * if partial writes are unwanted. * @todo Unused? */ VMMR3DECL(int) PGMR3DbgWriteGCPtr(PVM pVM, RTGCPTR GCPtrDst, void const *pvSrc, size_t cb, uint32_t fFlags, size_t *pcbWritten) { /* validate */ AssertReturn(!fFlags, VERR_INVALID_PARAMETER); AssertReturn(pVM, VERR_INVALID_PARAMETER); /* @todo SMP support! */ PVMCPU pVCpu = &pVM->aCpus[0]; /** @todo deal with HMA */ /* try simple first. */ int rc = PGMPhysSimpleWriteGCPtr(pVCpu, GCPtrDst, pvSrc, cb); if (RT_SUCCESS(rc) || !pcbWritten) return rc; /* partial write that failed, chop it up in pages. */ *pcbWritten = 0; rc = VINF_SUCCESS; while (cb > 0) { size_t cbChunk = PAGE_SIZE; cbChunk -= GCPtrDst & PAGE_OFFSET_MASK; if (cbChunk > cb) cbChunk = cb; rc = PGMPhysSimpleWriteGCPtr(pVCpu, GCPtrDst, pvSrc, cbChunk); /* advance */ if (RT_FAILURE(rc)) break; *pcbWritten += cbChunk; cb -= cbChunk; GCPtrDst += cbChunk; pvSrc = (uint8_t const *)pvSrc + cbChunk; } return *pcbWritten && RT_FAILURE(rc) ? -rc : rc; } /** * memchr() with alignment considerations. * * @returns Pointer to matching byte, NULL if none found. * @param pb Where to search. Aligned. * @param b What to search for. * @param cb How much to search . * @param uAlign The alignment restriction of the result. */ static const uint8_t *pgmR3DbgAlignedMemChr(const uint8_t *pb, uint8_t b, size_t cb, uint32_t uAlign) { const uint8_t *pbRet; if (uAlign <= 32) { pbRet = (const uint8_t *)memchr(pb, b, cb); if ((uintptr_t)pbRet & (uAlign - 1)) { do { pbRet++; size_t cbLeft = cb - (pbRet - pb); if (!cbLeft) { pbRet = NULL; break; } pbRet = (const uint8_t *)memchr(pbRet, b, cbLeft); } while ((uintptr_t)pbRet & (uAlign - 1)); } } else { pbRet = NULL; if (cb) { for (;;) { if (*pb == b) { pbRet = pb; break; } if (cb <= uAlign) break; cb -= uAlign; pb += uAlign; } } } return pbRet; } /** * Scans a page for a byte string, keeping track of potential * cross page matches. * * @returns true and *poff on match. * false on mismatch. * @param pbPage Pointer to the current page. * @param poff Input: The offset into the page (aligned). * Output: The page offset of the match on success. * @param cb The number of bytes to search, starting of *poff. * @param uAlign The needle alignment. This is of course less than a page. * @param pabNeedle The byte string to search for. * @param cbNeedle The length of the byte string. * @param pabPrev The buffer that keeps track of a partial match that we * bring over from the previous page. This buffer must be * at least cbNeedle - 1 big. * @param pcbPrev Input: The number of partial matching bytes from the previous page. * Output: The number of partial matching bytes from this page. * Initialize to 0 before the first call to this function. */ static bool pgmR3DbgScanPage(const uint8_t *pbPage, int32_t *poff, uint32_t cb, uint32_t uAlign, const uint8_t *pabNeedle, size_t cbNeedle, uint8_t *pabPrev, size_t *pcbPrev) { /* * Try complete any partial match from the previous page. */ if (*pcbPrev > 0) { size_t cbPrev = *pcbPrev; Assert(!*poff); Assert(cbPrev < cbNeedle); if (!memcmp(pbPage, pabNeedle + cbPrev, cbNeedle - cbPrev)) { if (cbNeedle - cbPrev > cb) return false; *poff = -(int32_t)cbPrev; return true; } /* check out the remainder of the previous page. */ const uint8_t *pb = pabPrev; for (;;) { if (cbPrev <= uAlign) break; cbPrev -= uAlign; pb = pgmR3DbgAlignedMemChr(pb + uAlign, *pabNeedle, cbPrev, uAlign); if (!pb) break; cbPrev = *pcbPrev - (pb - pabPrev); if ( !memcmp(pb + 1, &pabNeedle[1], cbPrev - 1) && !memcmp(pbPage, pabNeedle + cbPrev, cbNeedle - cbPrev)) { if (cbNeedle - cbPrev > cb) return false; *poff = -(int32_t)cbPrev; return true; } } *pcbPrev = 0; } /* * Match the body of the page. */ const uint8_t *pb = pbPage + *poff; const uint8_t *pbEnd = pb + cb; for (;;) { pb = pgmR3DbgAlignedMemChr(pb, *pabNeedle, cb, uAlign); if (!pb) break; cb = pbEnd - pb; if (cb >= cbNeedle) { /* match? */ if (!memcmp(pb + 1, &pabNeedle[1], cbNeedle - 1)) { *poff = pb - pbPage; return true; } } else { /* paritial match at the end of the page? */ if (!memcmp(pb + 1, &pabNeedle[1], cb - 1)) { /* We're copying one byte more that we really need here, but wtf. */ memcpy(pabPrev, pb, cb); *pcbPrev = cb; return false; } } /* no match, skip ahead. */ if (cb <= uAlign) break; pb += uAlign; cb -= uAlign; } return false; } /** * Scans guest physical memory for a byte string. * * @returns VBox status codes: * @retval VINF_SUCCESS and *pGCPtrHit on success. * @retval VERR_DBGF_MEM_NOT_FOUND if not found. * @retval VERR_INVALID_POINTER if any of the pointer arguments are invalid. * @retval VERR_INVALID_ARGUMENT if any other arguments are invalid. * * @param pVM Pointer to the shared VM structure. * @param GCPhys Where to start searching. * @param cbRange The number of bytes to search. * @param GCPhysAlign The alignment of the needle. Must be a power of two * and less or equal to 4GB. * @param pabNeedle The byte string to search for. * @param cbNeedle The length of the byte string. Max 256 bytes. * @param pGCPhysHit Where to store the address of the first occurence on success. */ VMMR3DECL(int) PGMR3DbgScanPhysical(PVM pVM, RTGCPHYS GCPhys, RTGCPHYS cbRange, RTGCPHYS GCPhysAlign, const uint8_t *pabNeedle, size_t cbNeedle, PRTGCPHYS pGCPhysHit) { /* * Validate and adjust the input a bit. */ if (!VALID_PTR(pGCPhysHit)) return VERR_INVALID_POINTER; *pGCPhysHit = NIL_RTGCPHYS; if ( !VALID_PTR(pabNeedle) || GCPhys == NIL_RTGCPHYS) return VERR_INVALID_POINTER; if (!cbNeedle) return VERR_INVALID_PARAMETER; if (cbNeedle > MAX_NEEDLE_SIZE) return VERR_INVALID_PARAMETER; if (!cbRange) return VERR_DBGF_MEM_NOT_FOUND; if (GCPhys + cbNeedle - 1 < GCPhys) return VERR_DBGF_MEM_NOT_FOUND; if (!GCPhysAlign) return VERR_INVALID_PARAMETER; if (GCPhysAlign > UINT32_MAX) return VERR_NOT_POWER_OF_TWO; if (GCPhysAlign & (GCPhysAlign - 1)) return VERR_INVALID_PARAMETER; if (GCPhys & (GCPhysAlign - 1)) { RTGCPHYS Adj = GCPhysAlign - (GCPhys & (GCPhysAlign - 1)); if ( cbRange <= Adj || GCPhys + Adj < GCPhys) return VERR_DBGF_MEM_NOT_FOUND; GCPhys += Adj; cbRange -= Adj; } const bool fAllZero = ASMMemIsAll8(pabNeedle, cbNeedle, 0) == NULL; const uint32_t cIncPages = GCPhysAlign <= PAGE_SIZE ? 1 : GCPhysAlign >> PAGE_SHIFT; const RTGCPHYS GCPhysLast = GCPhys + cbRange - 1 >= GCPhys ? GCPhys + cbRange - 1 : ~(RTGCPHYS)0; /* * Search the memory - ignore MMIO and zero pages, also don't * bother to match across ranges. */ pgmLock(pVM); for (PPGMRAMRANGE pRam = pVM->pgm.s.CTX_SUFF(pRamRanges); pRam; pRam = pRam->CTX_SUFF(pNext)) { /* * If the search range starts prior to the current ram range record, * adjust the search range and possibly conclude the search. */ RTGCPHYS off; if (GCPhys < pRam->GCPhys) { if (GCPhysLast < pRam->GCPhys) break; GCPhys = pRam->GCPhys; off = 0; } else off = GCPhys - pRam->GCPhys; if (off < pRam->cb) { /* * Iterate the relevant pages. */ uint8_t abPrev[MAX_NEEDLE_SIZE]; size_t cbPrev = 0; const uint32_t cPages = pRam->cb >> PAGE_SHIFT; uint32_t iPage = off >> PAGE_SHIFT; uint32_t offPage = GCPhys & PAGE_OFFSET_MASK; GCPhys &= ~(RTGCPHYS)PAGE_OFFSET_MASK; for (;; offPage = 0) { PPGMPAGE pPage = &pRam->aPages[iPage]; if ( ( !PGM_PAGE_IS_ZERO(pPage) || fAllZero) && !PGM_PAGE_IS_BALLOONED(pPage) && !PGM_PAGE_IS_MMIO(pPage)) { void const *pvPage; PGMPAGEMAPLOCK Lock; int rc = PGMPhysGCPhys2CCPtrReadOnly(pVM, GCPhys, &pvPage, &Lock); if (RT_SUCCESS(rc)) { int32_t offHit = offPage; bool fRc; if (GCPhysAlign < PAGE_SIZE) { uint32_t cbSearch = (GCPhys ^ GCPhysLast) & ~(RTGCPHYS)PAGE_OFFSET_MASK ? PAGE_SIZE - (uint32_t)offPage : (GCPhysLast & PAGE_OFFSET_MASK) + 1 - (uint32_t)offPage; fRc = pgmR3DbgScanPage((uint8_t const *)pvPage, &offHit, cbSearch, (uint32_t)GCPhysAlign, pabNeedle, cbNeedle, &abPrev[0], &cbPrev); } else fRc = memcmp(pvPage, pabNeedle, cbNeedle) == 0 && (GCPhysLast - GCPhys) >= cbNeedle; PGMPhysReleasePageMappingLock(pVM, &Lock); if (fRc) { *pGCPhysHit = GCPhys + offHit; pgmUnlock(pVM); return VINF_SUCCESS; } } else cbPrev = 0; /* ignore error. */ } else cbPrev = 0; /* advance to the next page. */ GCPhys += (RTGCPHYS)cIncPages << PAGE_SHIFT; if (GCPhys >= GCPhysLast) /* (may not always hit, but we're run out of ranges.) */ { pgmUnlock(pVM); return VERR_DBGF_MEM_NOT_FOUND; } iPage += cIncPages; if ( iPage < cIncPages || iPage >= cPages) break; } } } pgmUnlock(pVM); return VERR_DBGF_MEM_NOT_FOUND; } /** * Scans (guest) virtual memory for a byte string. * * @returns VBox status codes: * @retval VINF_SUCCESS and *pGCPtrHit on success. * @retval VERR_DBGF_MEM_NOT_FOUND if not found. * @retval VERR_INVALID_POINTER if any of the pointer arguments are invalid. * @retval VERR_INVALID_ARGUMENT if any other arguments are invalid. * * @param pVM Pointer to the shared VM structure. * @param pVCpu The CPU context to search in. * @param GCPtr Where to start searching. * @param GCPtrAlign The alignment of the needle. Must be a power of two * and less or equal to 4GB. * @param cbRange The number of bytes to search. Max 256 bytes. * @param pabNeedle The byte string to search for. * @param cbNeedle The length of the byte string. * @param pGCPtrHit Where to store the address of the first occurence on success. */ VMMR3DECL(int) PGMR3DbgScanVirtual(PVM pVM, PVMCPU pVCpu, RTGCPTR GCPtr, RTGCPTR cbRange, RTGCPTR GCPtrAlign, const uint8_t *pabNeedle, size_t cbNeedle, PRTGCUINTPTR pGCPtrHit) { VMCPU_ASSERT_EMT(pVCpu); /* * Validate and adjust the input a bit. */ if (!VALID_PTR(pGCPtrHit)) return VERR_INVALID_POINTER; *pGCPtrHit = 0; if (!VALID_PTR(pabNeedle)) return VERR_INVALID_POINTER; if (!cbNeedle) return VERR_INVALID_PARAMETER; if (cbNeedle > MAX_NEEDLE_SIZE) return VERR_INVALID_PARAMETER; if (!cbRange) return VERR_DBGF_MEM_NOT_FOUND; if (GCPtr + cbNeedle - 1 < GCPtr) return VERR_DBGF_MEM_NOT_FOUND; if (!GCPtrAlign) return VERR_INVALID_PARAMETER; if (GCPtrAlign > UINT32_MAX) return VERR_NOT_POWER_OF_TWO; if (GCPtrAlign & (GCPtrAlign - 1)) return VERR_INVALID_PARAMETER; if (GCPtr & (GCPtrAlign - 1)) { RTGCPTR Adj = GCPtrAlign - (GCPtr & (GCPtrAlign - 1)); if ( cbRange <= Adj || GCPtr + Adj < GCPtr) return VERR_DBGF_MEM_NOT_FOUND; GCPtr += Adj; cbRange -= Adj; } /* * Search the memory - ignore MMIO, zero and not-present pages. */ const bool fAllZero = ASMMemIsAll8(pabNeedle, cbNeedle, 0) == NULL; PGMMODE enmMode = PGMGetGuestMode(pVCpu); RTGCPTR GCPtrMask = PGMMODE_IS_LONG_MODE(enmMode) ? UINT64_MAX : UINT32_MAX; uint8_t abPrev[MAX_NEEDLE_SIZE]; size_t cbPrev = 0; const uint32_t cIncPages = GCPtrAlign <= PAGE_SIZE ? 1 : GCPtrAlign >> PAGE_SHIFT; const RTGCPTR GCPtrLast = GCPtr + cbRange - 1 >= GCPtr ? (GCPtr + cbRange - 1) & GCPtrMask : GCPtrMask; RTGCPTR cPages = (((GCPtrLast - GCPtr) + (GCPtr & PAGE_OFFSET_MASK)) >> PAGE_SHIFT) + 1; uint32_t offPage = GCPtr & PAGE_OFFSET_MASK; GCPtr &= ~(RTGCPTR)PAGE_OFFSET_MASK; for (;; offPage = 0) { RTGCPHYS GCPhys; int rc = PGMPhysGCPtr2GCPhys(pVCpu, GCPtr, &GCPhys); if (RT_SUCCESS(rc)) { PPGMPAGE pPage = pgmPhysGetPage(&pVM->pgm.s, GCPhys); if ( pPage && ( !PGM_PAGE_IS_ZERO(pPage) || fAllZero) && !PGM_PAGE_IS_BALLOONED(pPage) && !PGM_PAGE_IS_MMIO(pPage)) { void const *pvPage; PGMPAGEMAPLOCK Lock; rc = PGMPhysGCPhys2CCPtrReadOnly(pVM, GCPhys, &pvPage, &Lock); if (RT_SUCCESS(rc)) { int32_t offHit = offPage; bool fRc; if (GCPtrAlign < PAGE_SIZE) { uint32_t cbSearch = cPages > 0 ? PAGE_SIZE - (uint32_t)offPage : (GCPtrLast & PAGE_OFFSET_MASK) + 1 - (uint32_t)offPage; fRc = pgmR3DbgScanPage((uint8_t const *)pvPage, &offHit, cbSearch, (uint32_t)GCPtrAlign, pabNeedle, cbNeedle, &abPrev[0], &cbPrev); } else fRc = memcmp(pvPage, pabNeedle, cbNeedle) == 0 && (GCPtrLast - GCPtr) >= cbNeedle; PGMPhysReleasePageMappingLock(pVM, &Lock); if (fRc) { *pGCPtrHit = GCPtr + offHit; return VINF_SUCCESS; } } else cbPrev = 0; /* ignore error. */ } else cbPrev = 0; } else cbPrev = 0; /* ignore error. */ /* advance to the next page. */ if (cPages <= cIncPages) break; cPages -= cIncPages; GCPtr += (RTGCPTR)cIncPages << PAGE_SHIFT; } return VERR_DBGF_MEM_NOT_FOUND; }