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os-k/kaleid/kernel/mm/paging.c

420 lines
16 KiB
C

//----------------------------------------------------------------------------//
// GNU GPL OS/K //
// //
// Desc: Paging memory related functions //
// //
// //
// Copyright © 2018-2019 The OS/K Team //
// //
// This file is part of OS/K. //
// //
// OS/K is free software: you can redistribute it and/or modify //
// it under the terms of the GNU General Public License as published by //
// the Free Software Foundation, either version 3 of the License, or //
// any later version. //
// //
// OS/K is distributed in the hope that it will be useful, //
// but WITHOUT ANY WARRANTY//without even the implied warranty of //
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the //
// GNU General Public License for more details. //
// //
// You should have received a copy of the GNU General Public License //
// along with OS/K. If not, see <https://www.gnu.org/licenses/>. //
//----------------------------------------------------------------------------//
#include <kernel.h>
#include <init/boot.h>
#include <ke/idt.h>
#include <ex/malloc.h>
#include <mm/heap.h>
#include <mm/paging.h>
#include <mm/map.h>
#include <lib/buf.h>
#include <io/vga.h>
//-----------
pml4_t MmPageMapLevel4[512] __attribute__((__aligned__(KPAGESIZE)));
ulong *MmPhysicalPageTable;
extern ulong _text;
extern ulong _text_end;
extern ulong _rodata;
extern ulong _rodata_end;
extern ulong _data;
extern ulong _data_end;
extern MemoryMap_t memoryMap;
ulong MmStackGuards[2] = { 0 };
ulong MmVirtLastAddress = 0;
ulong MmPhysLastKernAddress = 0;
enum
{
PRESENT = 1 << 0,
READWRITE = 1 << 1,
USERMODE = 1 << 2,
WRITETHR = 1 << 3,
CACHEDIS = 1 << 4,
ACCESSED = 1 << 5,
DIRTY = 1 << 6,
HUGE = 1 << 7,
NX = 1UL << 63
};
//-----------
//
// Creates our new page table structure and loads it
//
void MmInitPaging(void)
{
pdpe_t *MmPDP = NULL;
pde_t *MmPD = NULL;
pte_t *MmPT = NULL;
ulong index, xedni;
ulong firstDirectoryAddr = 0;
ulong lastDirectoryAddr = 0;
ulong phDirSize = 0;
// Maximum PHYSICAL address in memory
ulong phRamSize = memoryMap.freeRamSize + memoryMap.nonfreeRamSize;
// Difference between the end of kernel and the begin of userspace
MmPhysLastKernAddress = (ulong)(_heap_start + _heap_max);
ulong diffKernUsr = (ulong)USERSPACE - MmPhysLastKernAddress - KPAGESIZE;
// Maximum VIRTUAL address in memory
MmVirtLastAddress = phRamSize + diffKernUsr;
//DebugLog("\tPaging gap : %u MB (%p)\n\tLast virtual address %p\n", diffKernUsr / MB, diffKernUsr, MmVirtLastAddress);
memzero((void *)&MmPageMapLevel4[0], sizeof(MmPageMapLevel4));
phDirSize = ((phRamSize / KPAGESIZE)*sizeof(ulong) + KPAGESIZE) & ( ~(KPAGESIZE - 1));
MmPhysicalPageTable = (ulong*)malloc(phDirSize);
//DebugLog("\t\tRam %u MB, pagesize %u KB, size %u MB\n", phRamSize / MB, KPAGESIZE / KB, phDirSize / MB);
for (ulong curAddrPML4 = 0;
curAddrPML4 < MmVirtLastAddress;
curAddrPML4 += ((ulong)KPAGESIZE * 0x8000000)) {
// Create an entry in PML4 each 512GB
// 0x8000000 = 512 ^ 3
MmPDP = (pdpe_t *)malloc(512*sizeof(pde_t));
if (!firstDirectoryAddr) {
firstDirectoryAddr = (ulong)MmPDP;
}
index = (curAddrPML4 / ((ulong)KPAGESIZE * 0x8000000)) % 512;
//DebugLog("\t\t\t\tPDP %d : %p\n", index, MmPDP);
MmPageMapLevel4[index] = (pdpe_t *)((ulong)MmPDP | PRESENT | READWRITE);
for (ulong curAddrPDP = curAddrPML4;
curAddrPDP < (curAddrPML4 + ((ulong)KPAGESIZE * 0x8000000)) &&
curAddrPDP < MmVirtLastAddress;
curAddrPDP += ((ulong)KPAGESIZE * 0x40000)) {
// Create an intry in PDP each 1GB
// 0x40000 = 512 ^ 2
MmPD = (pde_t *)malloc(512*sizeof(pde_t));
index = (curAddrPDP / ((ulong)KPAGESIZE * 0x40000)) % 512;
//DebugLog("\t\t\t\tPD %d : %p\n", index, MmPD);
MmPDP[index] = (pde_t *)((ulong)MmPD | PRESENT | READWRITE);
for (ulong curAddrPD = curAddrPDP;
curAddrPD < (curAddrPDP + ((ulong)KPAGESIZE * 0x40000)) &&
curAddrPD < MmVirtLastAddress;
curAddrPD += ((ulong)KPAGESIZE * 0x200)) {
// Create an intry in PD each 2MB
// 0x200 = 512
MmPT = (pte_t *)malloc(512*sizeof(pte_t));
index = (curAddrPD / ((ulong)KPAGESIZE * 0x200)) % 512;
//DebugLog("\t\t\t\tPT %d : %p\n", index, MmPT);
MmPD[index] = (pte_t *)((ulong)MmPT | PRESENT | READWRITE);
for (ulong curAddrPT = curAddrPD;
curAddrPT < (curAddrPD + ((ulong)KPAGESIZE * 0x200)) &&
curAddrPT < MmVirtLastAddress;
curAddrPT += (ulong)KPAGESIZE) {
// Create an entry in PT each page of 4KB
index = (curAddrPT / ((ulong)KPAGESIZE)) % 512;
xedni = (curAddrPT / ((ulong)KPAGESIZE));
//DebugLog("\t\t\t\tPage %d : %p\n", index, curAddrPT);
// STACK GUARD PAGE */
if ((ulong)curAddrPT == (ulong)BtLoaderInfo.stackEndAddr) {
MmPT[index] = (ulong)curAddrPT | PRESENT;
MmPhysicalPageTable[xedni] = (ulong)curAddrPT;
MmStackGuards[0] = (ulong)curAddrPT;
//DebugLog("\tStack Guard at %p\n", curAddrPT);
}
else if ((ulong)curAddrPT == (ulong)BtLoaderInfo.kernelEndAddr) {
MmPT[index] = (ulong)curAddrPT | PRESENT;
MmPhysicalPageTable[xedni] = (ulong)curAddrPT;
MmStackGuards[1] = (ulong)curAddrPT;
//DebugLog("\tStack Guard at %p\n", curAddrPT);
}
// SECTION .TEXT PROTECTION
else if ((ulong)curAddrPT >= (ulong)&_text && (ulong)curAddrPT <= (ulong)&_text_end) {
MmPT[index] = (ulong)curAddrPT | PRESENT;
MmPhysicalPageTable[xedni] = (ulong)curAddrPT;
//DebugLog("\tSection .text at %p\n", curAddrPT);
}
// SECTION .DATA PROTECTION
else if ((ulong)curAddrPT >= (ulong)&_data && (ulong)curAddrPT <= (ulong)&_data_end) {
MmPT[index] = (ulong)curAddrPT | PRESENT | WRITETHR | READWRITE | NX;
MmPhysicalPageTable[xedni] = (ulong)curAddrPT;
//DebugLog("\tSection .data at %p\n", curAddrPT);
}
// SECTION .RODATA PROTECTION
else if ((ulong)curAddrPT >= (ulong)&_rodata && (ulong)curAddrPT <= (ulong)&_rodata_end) {
MmPT[index] = (ulong)curAddrPT | PRESENT | WRITETHR | NX;
MmPhysicalPageTable[xedni] = (ulong)curAddrPT;
//DebugLog("\tSection .rodata at %p\n", curAddrPT);
}
// While we're inside the kernel pages
else if ((ulong)curAddrPT <= MmPhysLastKernAddress) {
MmPT[index] = (ulong)curAddrPT | PRESENT | READWRITE;
MmPhysicalPageTable[xedni] = (ulong)curAddrPT;
if ((ulong)curAddrPT == MmPhysLastKernAddress) {
//DebugLog("\tLast page of kernel at %p\n", curAddrPT);
}
}
/* // While we're inside the userspace pages */
/* else if ((ulong)curAddrPT >= USERSPACE) { */
/* MmPT[index] = ((ulong)curAddrPT - diffKernUsr) | PRESENT; // Not present for instance */
/* xedni = (((ulong)curAddrPT - diffKernUsr) / ((ulong)KPAGESIZE)); */
/* //MmPhysicalPageTable[xedni] = (ulong)curAddrPT; */
/* if ((ulong)curAddrPT == USERSPACE) { */
/* DebugLog("\tUserspace at %p:%p\n", curAddrPT, curAddrPT - diffKernUsr); */
/* } */
/* } */
else {
MmPT[index] = 0;
}
KeFlushTlbSingle(curAddrPT);
}
}
}
}
lastDirectoryAddr = (ulong)MmPT;
MmLoadPML4((void *)MmPageMapLevel4);
//MmEnableWriteProtect();
DebugLog("\tPage table size : %u MB\n", (lastDirectoryAddr - firstDirectoryAddr + phDirSize)/MB);
}
//
// Get a page from an address
//
static pte_t *MmGetPageDescriptorFromVirtual(void *virtualAddr)
{
ulong virtAddrPage = (ulong)virtualAddr & ( ~(KPAGESIZE - 1));
if (virtAddrPage > MmVirtLastAddress) {
KeStartPanic("MmSetPage() Out of bound of the address space !");
}
pdpe_t *pdp = (pdpe_t*)((ulong)MmPageMapLevel4[(virtAddrPage / ((ulong)KPAGESIZE * 0x8000000)) % 512] & ~(KPAGESIZE - 1));
//DebugLog("pdp\t: %p\n", pdp);
pde_t *pd = (pde_t*)( (ulong)pdp[(virtAddrPage / ((ulong)KPAGESIZE * 0x40000)) % 512] & ~(KPAGESIZE - 1));
//DebugLog("pd\t: %p\n", pd);
pte_t *pt = (pte_t*)( (ulong)pd[(virtAddrPage / ((ulong)KPAGESIZE * 0x200)) % 512] & ~(KPAGESIZE - 1));
//DebugLog("pt\t: %p\n", pt);
pte_t *page = &pt[(virtAddrPage / ((ulong)KPAGESIZE)) % 512];
//DebugLog("page (with flags): %p\n", page);
return page;
}
//
// Translates a virtual address to its physical equivalent
//
void *MmTransVirtToPhyAddr(void* virtualAddr)
{
ulong virtAddrPage = (ulong)virtualAddr & ( ~(KPAGESIZE - 1));
pte_t *page = MmGetPageDescriptorFromVirtual(virtualAddr);
if (*page == (*page & ~(KPAGESIZE - 1))) {
return NULL;
}
return (void*)((*page & ~(KPAGESIZE - 1))+ ((ulong)virtualAddr - (ulong)virtAddrPage));
}
void *MmTransPhyToVirtAddr(void* physicalAddr)
{
ulong phyAddrPage = (ulong)physicalAddr & ( ~(KPAGESIZE - 1));
return (void*)( MmPhysicalPageTable[(ulong)physicalAddr
/ ((ulong)KPAGESIZE)
] + ((ulong)physicalAddr - phyAddrPage));
}
//
// Add flags to a page
//
void MmSetPage(void* virtualAddr, ulong flags)
{
pte_t *page = MmGetPageDescriptorFromVirtual(virtualAddr);
*page |= flags;
KeFlushTlbSingle(*page);
}
//
// Remove flags of a page
//
void MmUnsetPage(void* virtualAddr, ulong flags)
{
pte_t *page = MmGetPageDescriptorFromVirtual(virtualAddr);
*page &= (~flags);
KeFlushTlbSingle(*page);
}
//
// Map a page in memory
//
void MmMapPage(void* virtualAddr, void* physicalAddr, ulong flags)
{
pte_t *page = MmGetPageDescriptorFromVirtual(virtualAddr);
*page = ((ulong)physicalAddr & ~(KPAGESIZE - 1)) | flags;
KeFlushTlbSingle(*page);
}
//
// Unmap a page in memory
//
void MmUnmapPage(void* virtualAddr)
{
pte_t *page = MmGetPageDescriptorFromVirtual(virtualAddr);
*page = 0;
KeFlushTlbSingle(*page);
}
//-----------
//
// Returns the rank of the Stack Guards
//
void *MmGetStackGuards(char rank)
{
return (void *)MmStackGuards[(int)rank];
}
//
// Page fault handler
//
static void PagingHandler(ISRFrame_t *regs)
{
ulong StackGuardOne = (ulong)MmGetStackGuards(0);
ulong StackGuardTwo = (ulong)MmGetStackGuards(1);
if ((regs->cr2 >= StackGuardOne) && (regs->cr2 <= StackGuardOne + KPAGESIZE) && (regs->rsp <= regs->cr2)) {
bprintf(BStdOut,
"\n\n%CPANIC\n[ISR 0x8] Irrecoverable Kernel Stack Underflow\n\n"
" Page Fault Error code : %#x (%b)\n"
" Stack Guard bypassed : %#x",
VGA_COLOR_LIGHT_RED,
regs->ErrorCode,
regs->ErrorCode,
StackGuardOne
);
} else if ((regs->cr2 >= StackGuardTwo) && (regs->cr2 <= StackGuardTwo + KPAGESIZE) && (regs->rsp >= regs->cr2)) {
bprintf(BStdOut,
"\n\n%CPANIC\n[ISR 0x8] Irrecoverable Kernel Stack Overflow\n\n"
" Page Fault Error code : %#x (%b)\n"
" Stack Guard bypassed : %#x",
VGA_COLOR_LIGHT_RED,
regs->ErrorCode,
regs->ErrorCode,
StackGuardTwo
);
} else if (regs->cr2 == 0) {
bprintf(BStdOut,
"\n\n%CPANIC\n[ISR 0x8] Null vector exception !\n\n"
" Page Fault Error code : %#x (%b)\n",
VGA_COLOR_LIGHT_RED,
regs->intNo,
regs->ErrorCode,
regs->ErrorCode
);
} else if (regs->cr2 >= MmVirtLastAddress || regs->cr2 <= 0) {
bprintf(BStdOut,
"\n\n%CPANIC\n[ISR 0x8] Out of bound of the address space at %p !\n\n"
" End of the address space : %p\n"
" Page Fault Error code : %#x (%b)\n",
VGA_COLOR_LIGHT_RED,
regs->cr2,
MmVirtLastAddress,
regs->ErrorCode,
regs->ErrorCode
);
} else {
//XXX page fault
bprintf(BStdOut, "\n\n%CPANIC\n[ISR 0x8] Irrecoverable Page Fault at %p\n\n"
" Error code : 0x%x (%b)",
VGA_COLOR_LIGHT_RED,
regs->cr2,
regs->ErrorCode,
regs->ErrorCode
);
}
bprintf(BStdOut, "\n Description : ");
if (regs->ErrorCode & PRESENT) {
bprintf(BStdOut, "Page-protection violation ");
} else {
bprintf(BStdOut, "Non present page ");
}
if (regs->ErrorCode & READWRITE) {
bprintf(BStdOut, "during write access ");
} else {
bprintf(BStdOut, "during read access ");
}
if (regs->ErrorCode & (1 << 3))
bprintf(BStdOut, "from userspace ");
if (regs->ErrorCode & (1 << 4))
bprintf(BStdOut, "after instruction fetching ");
KeBrkDumpRegisters(regs);
BStdOut->flusher(BStdOut);
KeHaltCPU();
}
void MmActivatePageHandler(void)
{
KeRegisterISR(PagingHandler, 0xe);
DebugLog("\tPaging activated\n");
}