/*-
* Copyright (c) 2002-2018 The UbixOS Project.
* All rights reserved.
*
* This was developed by Christopher W. Olsen for the UbixOS Project.
*
* Redistribution and use in source and binary forms, with or without modification, are permitted
* provided that the following conditions are met:
*
* 1) Redistributions of source code must retain the above copyright notice, this list of
* conditions, the following disclaimer and the list of authors.
* 2) Redistributions in binary form must reproduce the above copyright notice, this list of
* conditions, the following disclaimer and the list of authors in the documentation and/or
* other materials provided with the distribution.
* 3) Neither the name of the UbixOS Project nor the names of its contributors may be used to
* endorse or promote products derived from this software without specific prior written
* permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,
* OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <vmm/vmm.h>
#include <ubixos/sched.h>
#include <ubixos/kpanic.h>
#include <ubixos/spinlock.h>
#include <lib/kprintf.h>
#include <sys/trap.h>
static struct spinLock pageFaultSpinLock = SPIN_LOCK_INITIALIZER;
/*****************************************************************************************
Function: void vmm_pageFault(uInt32 memAddr,uInt32 eip,uInt32 esp);
Description: This is the page fault handler, it will handle COW and trap all other
exceptions and segfault the thread.
Notes:
07/30/02 - Fixed COW However I Need To Think Of A Way To Impliment
A Paging System Also Start To Add Security Levels
07/27/04 - Added spin locking to ensure that we are thread safe. I know that spining a
cpu is a waste of resources but for now it prevents errors.
*****************************************************************************************/
/* void vmm_pageFault(uInt32 memAddr,uInt32 eip,uInt32 esp) { */
void vmm_pageFault(struct trapframe *frame, uint32_t cr2) {
uInt32 i = 0x0, pageTableIndex = 0x0, pageDirectoryIndex = 0x0;
uInt32 *pageDir = 0x0, *pageTable = 0x0;
uInt32 *src = 0x0, *dst = 0x0;
uint32_t esp = frame->tf_esp;
uint32_t eip = frame->tf_eip;
uint32_t memAddr = cr2;
//MrOlsen 2017-12-15 -
kprintf("CR2: [0x%X], EIP: 0x%X, ERR: 0x%X\n", cr2, frame->tf_eip, frame->tf_err);
/* Try to aquire lock otherwise spin till we do */
spinLock(&pageFaultSpinLock);
/* Set page dir pointer to the address of the visable page directory */
pageDir = (uInt32 *) PD_BASE_ADDR;
/* UBU - This is a temp panic for 0x0 read write later on I will handle this differently */
if (memAddr == 0x0) {
kprintf("Segfault At Address: [0x%X], ESP: [0x%X], PID: [%i], EIP: [0x%X]\n", memAddr, esp, _current->id, eip);
kpanic("Error We Wrote To 0x0\n");
}
/* Calculate The Page Directory Index */
pageDirectoryIndex = (memAddr >> 22);
/* Calculate The Page Table Index */
pageTableIndex = ((memAddr >> 12) & 0x3FF);
/* UBU - This is a temporary routine for handling access to a page of a non existant page table */
if (pageDir[pageDirectoryIndex] == 0x0) {
kprintf("Segfault At Address: [0x%X][0x%X][%i][0x%X], Not A Valid Page Table\n", memAddr, esp, _current->id, eip);
spinUnlock(&pageFaultSpinLock);
endTask(_current->id);
}
else {
/* Set pageTable To Point To Virtual Address Of Page Table */
pageTable = (uInt32 *) (PT_BASE_ADDR + (0x1000 * pageDirectoryIndex));
/* Test if this is a COW on page */
if (((uInt32) pageTable[pageTableIndex] & PAGE_COW) == PAGE_COW) {
/* Set Src To Base Address Of Page To Copy */
src = (uInt32 *) (memAddr & 0xFFFFF000);
/* Allocate A Free Page For Destination */
/* USE vmInfo */
dst = (uInt32 *) vmm_getFreeVirtualPage(_current->id, 1, 0x1);
/* Copy Memory */
for (i = 0; i < PD_ENTRIES; i++) {
dst[i] = src[i];
}
/* Adjust The COW Counter For Physical Page */
adjustCowCounter(((uInt32) pageTable[pageTableIndex] & 0xFFFFF000), -1);
/* Remap In New Page */
pageTable[pageTableIndex] = (uInt32) (vmm_getPhysicalAddr((uInt32) dst) | (memAddr & 0xFFF));
/* Unlink From Memory Map Allocated Page */
vmm_unmapPage((uInt32) dst, 1);
}
else if (pageTable[pageTableIndex] != 0x0) {
kprintf("Security failed pagetable not user permission\n");
kprintf("pageDir: [0x%X]\n", pageDir[pageDirectoryIndex]);
kprintf("pageTable: [0x%X:0x%X:0x%X:0x%X]\n", pageTable[pageTableIndex], pageTableIndex, pageDirectoryIndex, eip);
kprintf("Segfault At Address: [0x%X][0x%X][%i][0x%X] Non Mapped\n", memAddr, esp, _current->id, eip);
spinUnlock(&pageFaultSpinLock);
endTask(_current->id);
}
else if (memAddr < (_current->td.vm_dsize + _current->td.vm_daddr)) {
kprintf("THIS IS BAD");
pageTable[pageTableIndex] = (uInt32) vmm_findFreePage(_current->id) | PAGE_DEFAULT;
}
else {
spinUnlock(&pageFaultSpinLock);
/* Need To Create A Routine For Attempting To Access Non Mapped Memory */
kprintf("pageDir: [0x%X]\n", pageDir[pageDirectoryIndex]);
kprintf("pageTable: [0x%X:0x%X:0x%X:0x%X]\n", pageTable[pageTableIndex], pageTableIndex, pageDirectoryIndex, eip);
kprintf("Segfault At Address: [0x%X][0x%X][%i][0x%X] Non Mapped\n", memAddr, esp, _current->id, eip);
kprintf("Out Of Stack Space: [0x%X]\n", memAddr & 0xFF0000);
spinUnlock(&pageFaultSpinLock);
endTask(_current->id);
}
}
asm volatile(
"movl %cr3,%eax\n"
"movl %eax,%cr3\n"
);
/* Release the spin lock */
spinUnlock(&pageFaultSpinLock);
kprintf("CR2-RET");
return;
}
/***
$Log: pagefault.c,v $
Revision 1.6 2006/12/05 14:10:21 reddawg
Workign Distro
Revision 1.5 2006/12/01 05:12:35 reddawg
We're almost there... :)
Revision 1.4 2006/11/21 13:25:49 reddawg
A handful of changes ;)
Revision 1.3 2006/11/06 19:10:12 reddawg
Lots Of Updates... Still having issues with brk();
Revision 1.2 2006/10/31 20:44:19 reddawg
Lots of changes
Revision 1.1.1.1 2006/06/01 12:46:13 reddawg
ubix2
Revision 1.2 2005/10/12 00:13:38 reddawg
Removed
Revision 1.1.1.1 2005/09/26 17:24:52 reddawg
no message
Revision 1.14 2004/08/25 22:02:41 reddawg
task switching - We now are using software switching to be consistant with the rest of the world because all of this open source freaks gave me a hard time about something I liked. There doesn't seem to be any gain in performance but it is working fine and flawlessly
Revision 1.13 2004/08/24 05:24:37 reddawg
TCA Is A BONER!!!!
Revision 1.12 2004/08/14 11:23:03 reddawg
Changes
Revision 1.11 2004/07/28 15:05:43 reddawg
Major:
Pages now have strict security enforcement.
Many null dereferences have been resolved.
When apps loaded permissions set for pages rw and ro
Revision 1.10 2004/07/28 00:22:56 reddawg
bah
Revision 1.9 2004/07/28 00:17:05 reddawg
Major:
Disconnected page 0x0 from the system... Unfortunately this broke many things
all of which have been fixed. This was good because nothing deferences NULL
any more.
Things affected:
malloc,kmalloc,getfreepage,getfreevirtualpage,pagefault,fork,exec,ld,ld.so,exec,file
Revision 1.8 2004/07/27 07:09:38 reddawg
Put in a test for 0x0
Revision 1.7 2004/07/26 19:15:49 reddawg
test code, fixes and the like
Revision 1.6 2004/07/24 23:04:44 reddawg
Changes... mark let me know if you fault at pid 185 when you type stress
Revision 1.5 2004/07/24 20:00:51 reddawg
Lots of changes to the vmm subsystem.... Page faults have been adjust to now be blocking on a per thread basis not system wide. This has resulted in no more deadlocks.. also the addition of per thread locking has removed segfaults as a result of COW in which two tasks fault the same COW page and try to modify it.
Revision 1.4 2004/07/24 17:47:28 reddawg
vmm_pageFault: deadlock resolved thanks to a propper solution suggested by geist
Revision 1.3 2004/07/19 02:05:26 reddawg
vmmPageFault: had a potential memory leak here for one page it was still using sysID on certain COW scenarios
Revision 1.2 2004/06/10 22:23:56 reddawg
Volatiles
Revision 1.1.1.1 2004/04/15 12:06:52 reddawg
UbixOS v1.0
Revision 1.4 2004/04/13 16:36:34 reddawg
Changed our copyright, it is all now under a BSD-Style license
END
***/
