virtmem.c

可用于嵌入式编程学习

            AddAccess(&pmbSrc->alk, pCurProc->aky);
            (*pscnDest)[ixDestBlk] = pmbSrc;
            cPages -= PAGES_PER_BLOCK;
#if defined(SH4) && (PAGE_SIZE==4096)
        } else if (bPhys && !ixPage && !(ixDestBlk & 15) && !(ulPFN&1048575) && (cPages >= 256)) {
			int loop, loop2;
			DWORD dwSetting = ulPgMask | PG_1M_MASK;
			for (loop = 0; loop < 16; loop++) {
				pmbDest = (*pscnDest)[ixDestBlk+loop];
				for (loop2 = 0; loop2 < 16; loop2++) {
		        	pmbDest->aPages[loop2] = dwSetting | ulPFN;
   			        ulPFN = NextPFN(ulPFN);
   			    }
   			}
			cPages-=256;
			ixDestBlk+=15;
#endif				
		} else {
            for ( ; cPages && ixPage < PAGES_PER_BLOCK ; ++ixPage, --cPages) {
                if (bPhys) {
                    DEBUGMSG(ZONE_VIRTMEM,
                        (TEXT("Mapping physical page %8.8lx @%3.3x%x000 perm=%x\r\n"),
                        ulPFN, ixDestBlk, ixPage, ulPgMask));
#if 0
#if defined(SH3) && (PAGE_SIZE==1024)
					if (!(ixPage&3) && !(ulPFN&4095) && (cPages >= 4)) {
						int loop;
						DWORD dwSetting = ulPgMask | PG_4K_MASK;
						for (loop = 0; loop < 4; loop++) {
			                DEBUGCHK(pmbDest->aPages[ixPage+loop] == 0);
		                    pmbDest->aPages[ixPage+loop] = dwSetting | ulPFN;
	   		                ulPFN = NextPFN(ulPFN);
	   		            }
						ixPage+=3;
						cPages-=3;
					} else {
		                DEBUGCHK(pmbDest->aPages[ixPage] == 0);
	                    pmbDest->aPages[ixPage] = ulPFN | ulPgMask;
    	                ulPFN = NextPFN(ulPFN);
    	            }
#elif defined(SH4) && (PAGE_SIZE==4096)
					if (!(ixPage&15) && !(ulPFN&65535) && (cPages >= 16)) {
						int loop;
						DWORD dwSetting = (ulPgMask & ~PG_1M_MASK) | PG_64K_MASK;
						for (loop = 0; loop < 16; loop++) {
			                DEBUGCHK(pmbDest->aPages[ixPage+loop] == 0);
		                    pmbDest->aPages[ixPage+loop] = dwSetting | ulPFN;
	   		                ulPFN = NextPFN(ulPFN);
	   		            }
						ixPage+=15;
						cPages-=15;
					} else {
		                DEBUGCHK(pmbDest->aPages[ixPage] == 0);
	                    pmbDest->aPages[ixPage] = ulPFN | ulPgMask;
    	                ulPFN = NextPFN(ulPFN);
    	            }
#else
	                DEBUGCHK(pmbDest->aPages[ixPage] == 0);
                    pmbDest->aPages[ixPage] = ulPFN | ulPgMask;
                    ulPFN = NextPFN(ulPFN);
#endif
#else
	                DEBUGCHK(pmbDest->aPages[ixPage] == 0);
                    pmbDest->aPages[ixPage] = ulPFN | ulPgMask;
                    ulPFN = NextPFN(ulPFN);
#endif
                } else {
                	DWORD dwOrig = pmbSrc->aPages[ixPage];
                    DEBUGCHK(dwOrig != 0 && dwOrig != BAD_PAGE);
                    ulPFN = PFNfromEntry(dwOrig);
                    DupPhysPage(ulPFN);
                    DEBUGMSG(ZONE_VIRTMEM, (TEXT("Copying page %8.8lx @%3.3x%x000 perm=%x\r\n"),
                            ulPFN, ixDestBlk, ixPage, ulPgMask));
#if defined(SH3) && (PAGE_SIZE==1024)
                    pmbDest->aPages[ixPage] = ulPFN | ulPgMask | (dwOrig & PG_4K_MASK);
#elif defined(SH4) && (PAGE_SIZE==4096)
                    pmbDest->aPages[ixPage] = ulPFN | (ulPgMask & ~PG_1M_MASK) | (dwOrig & PG_1M_MASK);
#else
                    pmbDest->aPages[ixPage] = ulPFN | ulPgMask;
#endif
                }
            }
        }
        ixPage = 0;            /* start with first page of next block */
    }
    LeaveCriticalSection(&VAcs);
    return TRUE;
invalidParm:
    LeaveCriticalSection(&VAcs);
    DEBUGMSG(ZONE_VIRTMEM, (TEXT("VirtualCopy failed.\r\n")));
    KSetLastError(pCurThread, ERROR_INVALID_PARAMETER);
    return FALSE;
}

BOOL SC_VirtualCopy(LPVOID lpvDest, LPVOID lpvSrc, DWORD cbSize, DWORD fdwProtect) {
	if (pCurProc->bTrustLevel != KERN_TRUST_FULL) {
		ERRORMSG(1,(L"SC_VirtualCopy failed due to insufficient trust\r\n"));
	    KSetLastError(pCurThread, ERROR_ACCESS_DENIED);
    	return 0;
	}
	return DoVirtualCopy(lpvDest, lpvSrc, cbSize, fdwProtect);
}

#ifdef SH4
BOOL SC_VirtualSetPageFlags(LPVOID lpvAddress, DWORD cbSize, DWORD dwFlags, LPDWORD lpdwOldFlags) {
	DWORD bits;
    int ixBlock;
    int ixPage;
    int ixFirB;         /* index of first block in region */
    PSECTION pscn;
    int cPages;         /* # of pages to adjust */
    MEMBLOCK *pmb;
	if (pCurProc->bTrustLevel != KERN_TRUST_FULL) {
		ERRORMSG(1,(L"SC_VirtualSetPageFlags failed due to insufficient trust\r\n"));
	    KSetLastError(pCurThread, ERROR_ACCESS_DENIED);
    	return 0;
	}
	switch (dwFlags & ~VSPF_TC) {
		case VSPF_NONE:
			bits = 0;
			break;
		case VSPF_VARIABLE:
			bits = 1;
			break;
		case VSPF_IOSPACE:
			bits = 2;
			break;
		case VSPF_IOSPACE | VSPF_16BIT:
			bits = 3;
			break;
		case VSPF_COMMON:
			bits = 4;
			break;
		case VSPF_COMMON | VSPF_16BIT:
			bits = 5;
			break;
		case VSPF_ATTRIBUTE:
			bits = 6;
			break;
		case VSPF_ATTRIBUTE | VSPF_16BIT:
			bits = 7;
			break;
		default:
			KSetLastError(pCurThread,ERROR_INVALID_PARAMETER);
			return FALSE;
	}
	bits <<= 29;
	if (dwFlags & VSPF_TC)
	   bits |= (1 << 9);
    EnterCriticalSection(&VAcs);
	if (!cbSize || !lpvAddress || (cbSize & 0x80000000) || ((ulong)lpvAddress>>VA_SECTION > SECTION_MASK))
		goto invalidParm;
    pscn = SectionTable[((ulong)lpvAddress>>VA_SECTION) & SECTION_MASK];
    if (pscn == NULL_SECTION)
        goto invalidParm;
    ixBlock = ((ulong)lpvAddress >> VA_BLOCK) & BLOCK_MASK;
    if ((ixFirB = FindFirstBlock(pscn, ixBlock)) == UNKNOWN_BASE)
        goto invalidParm;
    /* Verify that all of the pages within the specified range belong to the same VirtualAlloc region and are committed.
     *  (pscn) = ptr to section array
     *  (ixBlock) = index of block containing the first page of lpvAddress
     *  (ixFirB) = index of first block in the region
     */
    ixPage = ((ulong)lpvAddress >> VA_PAGE) & PAGE_MASK;
    cPages = (((ulong)lpvAddress + cbSize + PAGE_SIZE-1) / PAGE_SIZE)
            - ((ulong)lpvAddress / PAGE_SIZE);
    if (ScanRegion(pscn, ixFirB, ixBlock, ixPage, cPages, 0) != 0)
        goto invalidParm;
    /* Walk the page tables to set the new page permissions */
    if (lpdwOldFlags) {
    	switch ((*pscn)[ixBlock]->aPages[ixPage] >> 29) {
		    	case 0:
				*lpdwOldFlags = VSPF_NONE;
				break;
			case 1:
				*lpdwOldFlags = VSPF_VARIABLE;
				break;
			case 2:
				*lpdwOldFlags = VSPF_IOSPACE;
				break;
			case 3:
				*lpdwOldFlags = VSPF_IOSPACE | VSPF_16BIT;
				break;
			case 4:
				*lpdwOldFlags = VSPF_COMMON;
				break;
			case 5:
				*lpdwOldFlags = VSPF_COMMON | VSPF_16BIT;
				break;
			case 6:
				*lpdwOldFlags = VSPF_ATTRIBUTE;
				break;
			case 7:
				*lpdwOldFlags = VSPF_ATTRIBUTE | VSPF_16BIT;
				break;
		}
		if (((*pscn)[ixBlock]->aPages[ixPage] >> 9) & 1)
		    *lpdwOldFlags |= VSPF_TC;
	}
    for (; cPages ; ++ixBlock) {
        pmb = (*pscn)[ixBlock];
        do {
            DEBUGCHK(pmb->aPages[ixPage] != 0 && pmb->aPages[ixPage] != BAD_PAGE);
            DEBUGMSG(ZONE_VIRTMEM, (TEXT("Setting extra bits @%3.3x%x000 bits=%x\r\n"), ixBlock, ixPage, bits));
            pmb->aPages[ixPage] = (pmb->aPages[ixPage] & 0x1ffffdff) | bits;
        } while (--cPages && ++ixPage < PAGES_PER_BLOCK);
        ixPage = 0;            /* start with first page of next block */
    }
    LeaveCriticalSection(&VAcs);
    return TRUE;
invalidParm:
    LeaveCriticalSection(&VAcs);
    DEBUGMSG(ZONE_VIRTMEM, (TEXT("VirtualSetPageFlags failed.\r\n")));
    KSetLastError(pCurThread, ERROR_INVALID_PARAMETER);
    return FALSE;
}
#endif

BOOL SC_VirtualProtect(
LPVOID lpvAddress,      /* address of region of committed pages */
DWORD cbSize,           /* size of the region */
DWORD fdwNewProtect,    /* desired access protection */
PDWORD pfdwOldProtect)  /* address of variable to get old protection */
{
    int ixBlock;
    int ixPage;
    int ixFirB;         /* index of first block in region */
    PSECTION pscn;
    int cPages;         /* # of pages to adjust */
    ulong ulPgMask;     /* page permissions */
    MEMBLOCK *pmb;
    BOOL bRet = TRUE;
    DEBUGMSG(ZONE_VIRTMEM, (TEXT("VirtualProtect @%8.8lx size=%lx fdwNewProtect=%lx\r\n"),
            lpvAddress, cbSize, fdwNewProtect));
    if ((ulPgMask = MakePagePerms(fdwNewProtect)) == 0)
        return FALSE;       /* invalid protection flags, error # already set */
    /* Verify that the requested region is within range and within an
     * existing reserved memory region that the client is allowed to
     * access and locate the starting block of the region.
     */
    /* Lockout other changes to the virtual memory state. */
    EnterCriticalSection(&VAcs);
    if (cbSize == 0 || pfdwOldProtect == 0)
        goto invalidParm;
    if (lpvAddress == 0 || (ulong)lpvAddress>>VA_SECTION > SECTION_MASK)
        goto invalidParm;
    pscn = SectionTable[((ulong)lpvAddress>>VA_SECTION) & SECTION_MASK];
    if (pscn == NULL_SECTION)
        goto invalidParm;
    ixBlock = ((ulong)lpvAddress >> VA_BLOCK) & BLOCK_MASK;
    if ((ixFirB = FindFirstBlock(pscn, ixBlock)) == UNKNOWN_BASE)
        goto invalidParm;
    /* Verify that all of the pages within the specified range belong to the
     * same VirtualAlloc region and are committed.
     *
     *  (pscn) = ptr to section array
     *  (ixBlock) = index of block containing the first page of lpvAddress
     *  (ixFirB) = index of first block in the region
     */
    ixPage = ((ulong)lpvAddress >> VA_PAGE) & PAGE_MASK;
    cPages = (((ulong)lpvAddress + cbSize + PAGE_SIZE-1) / PAGE_SIZE)
            - ((ulong)lpvAddress / PAGE_SIZE);
    if (ScanRegion(pscn, ixFirB, ixBlock, ixPage, cPages, 0) != 0)
        goto invalidParm;
    /* Walk the page tables to set the new page permissions */
    *pfdwOldProtect = ProtectFromPerms((*pscn)[ixBlock]->aPages[ixPage]);
    for (; cPages ; ++ixBlock) {
        pmb = (*pscn)[ixBlock];
        do {
	        if (!pmb->cLocks || ((ulPgMask & (PG_VALID_MASK | PG_PROT_WRITE)) == (PG_VALID_MASK | PG_PROT_WRITE))) {
    	        DEBUGCHK(pmb->aPages[ixPage] != 0 && pmb->aPages[ixPage] != BAD_PAGE);
        	    DEBUGMSG(ZONE_VIRTMEM, (TEXT("Changing perms @%3.3x%x000 perm=%x\r\n"),
            	        ixBlock, ixPage, ulPgMask));
#if defined(SH3) && (PAGE_SIZE == 1024)
	            pmb->aPages[ixPage] = (pmb->aPages[ixPage] & ~(PG_PERMISSION_MASK & ~PG_4K_MASK)) | ulPgMask;
#elif defined(SH4) && (PAGE_SIZE == 4096)
        	    pmb->aPages[ixPage] = (pmb->aPages[ixPage] & ~(PG_PERMISSION_MASK & ~PG_1M_MASK)) | (ulPgMask & ~PG_1M_MASK);
#else
	            pmb->aPages[ixPage] = (pmb->aPages[ixPage] & ~PG_PERMISSION_MASK) | ulPgMask;
#endif
	    	} else {
	    		DEBUGMSG(1,(L"VirtualProtect: Cannot reduce access at %8.8lx, lock count %d\r\n",
					((DWORD)lpvAddress & (SECTION_MASK<<VA_SECTION)) + (ixBlock<<VA_BLOCK) + (ixPage<<VA_PAGE), pmb->cLocks));
				if (cbSize == PAGE_SIZE)
					bRet = FALSE;
	    	}
   	    } while (--cPages && ++ixPage < PAGES_PER_BLOCK);
        ixPage = 0;            /* start with first page of next block */
    }
    // Since page permissions have been modified, it is necessary to flush the TLB.
    InvalidateRange(lpvAddress, cbSize);
    LeaveCriticalSection(&VAcs);
    return bRet;
invalidParm:
    LeaveCriticalSection(&VAcs);
    DEBUGMSG(ZONE_VIRTMEM, (TEXT("VirtualProtect failed.\r\n")));
    KSetLastError(pCurThread, ERROR_INVALID_PARAMETER);
    return FALSE;
}

DWORD SC_VirtualQuery(
LPVOID lpvAddress,      /* address of region */
PMEMORY_BASIC_INFORMATION pmbiBuffer,   /* address of information buffer */
DWORD cbLength)         /* size of buffer */
{
    int ixBlock;
    int ixPage;
    int ixFirB;         /* index of first block in region */
    PSECTION pscn;
    MEMBLOCK *pmb;
    int cPages;
    ulong ulPgPerm;
    if (cbLength < sizeof(MEMORY_BASIC_INFORMATION)) {
        KSetLastError(pCurThread, ERROR_BAD_LENGTH);
        return 0;
    }
    DEBUGMSG(ZONE_VIRTMEM, (TEXT("VirtualQuery @%8.8lx buf=%8.8lx cbLen=%d\r\n"),
            lpvAddress, pmbiBuffer, cbLength));