Merge branch 'paging' into paging-fork

Conflicts:
	arch/x86/mm/page.c
This commit is contained in:
Steffen Vogel 2014-11-28 02:45:05 +01:00
commit 1a20a9fb45
5 changed files with 52 additions and 63 deletions

View file

@ -20,9 +20,18 @@ OBJCOPY_FOR_TARGET = $(CROSSCOMPREFIX)objcopy
RANLIB_FOR_TARGET = $(CROSSCOMPREFIX)ranlib
STRIP_FOR_TARGET = $(CROSSCOMPREFIX)strip
READELF_FOR_TARGET = $(CROSSCOMPREFIX)readelf
NASM = nasm
GDB = gdb
QEMU = qemu-system-i386
NASMFLAGS = -felf32 -g -i$(TOPDIR)/include/eduos/
GDBFLAGS = -x debug.gdb
QEMUFLAGS = -smp 2 -monitor stdio \
-net nic,model=rtl8139 \
-net user,hostfwd=tcp::12345-:7 \
-serial tcp::12346,server,nowait
INCLUDE = -I$(TOPDIR)/include -I$(TOPDIR)/arch/$(ARCH)/include
# Compiler options for final code
CFLAGS = -g -m32 -march=i586 -Wall -O2 -fno-builtin -fstrength-reduce -fomit-frame-pointer -finline-functions -nostdinc $(INCLUDE) -fno-stack-protector
@ -62,14 +71,15 @@ veryclean: clean
@echo Very cleaned
qemu: $(NAME).elf
qemu-system-i386 -monitor stdio -smp 2 -net nic,model=rtl8139 -net user,hostfwd=tcp::12345-:7 -net dump -kernel $(NAME).elf
$(QEMU) $(QEMUFLAGS) -kernel $(NAME).elf
qemu-dbg: $(NAME).elf
qemu-system-i386 -monitor stdio -s -S -smp 2 -net nic,model=rtl8139 -net user,hostfwd=tcp::12345-:7 -net dump -kernel $(NAME).elf
debug: $(NAME).elf
$(TERM) -e $(GDB) $(GDBFLAGS) &
$(QEMU) $(QEMUFLAGS) -s -S -kernel $(NAME).elf
doc:
@doxygen
@echo Create documentation...
@doxygen
%.o : %.c
@echo [CC] $@
@ -91,5 +101,5 @@ include/eduos/config.inc: include/eduos/config.h
$Q$(CC_FOR_TARGET) $(CFLAGS) -c -o $@ $<
.PHONY: default all clean emu gdb newlib tools
include $(addsuffix /Makefile,$(SUBDIRS))

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@ -88,6 +88,8 @@
/// This page or table is used during the boot process
#define PG_BOOT (1 << 9)
/// This page is reserved for copying
#define PAGE_TMP (PAGE_FLOOR((size_t) &kernel_start) - PAGE_SIZE)
/** @brief Converts a virtual address to a physical
*

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@ -24,6 +24,11 @@
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/**
* This is a 32/64 bit portable paging implementation for the x86 architecture
* using self-referenced page tables.
* See http://www.noteblok.net/2014/06/14/bachelor/ for a detailed description.
*/
#include <eduos/stdio.h>
#include <eduos/memory.h>
@ -53,21 +58,10 @@ static size_t* self[PAGE_LEVELS] = {
(size_t *) 0xFFFFF000
};
/** @todo: replace these offset by something meaningful */
static size_t * other[PAGE_LEVELS] = {
(size_t *) 0xFF800000,
(size_t *) 0xFFFFE000
};
/** Addresses of child/parent tables */
/* Addresses of child/parent tables */
#define CHILD(map, lvl, vpn) &map[lvl-1][vpn<<PAGE_MAP_BITS]
#define PARENT(map, lvl, vpn) &map[lvl+1][vpn>>PAGE_MAP_BITS]
/** This page is reserved for copying */
#define PAGE_TMP (PAGE_FLOOR((size_t) &kernel_start) - PAGE_SIZE)
/** @todo Does't handle huge pages for now
* @todo This will cause a pagefaut if addr isn't mapped! */
size_t page_virt_to_phys(size_t addr)
{
size_t vpn = addr >> PAGE_BITS; // virtual page number
@ -84,7 +78,7 @@ int page_map(size_t viraddr, size_t phyaddr, size_t npages, size_t bits)
long vpn = viraddr >> PAGE_BITS;
long first[PAGE_LEVELS], last[PAGE_LEVELS];
// calculate index boundaries for page map traversal
/* Calculate index boundaries for page map traversal */
for (lvl=0; lvl<PAGE_LEVELS; lvl++) {
first[lvl] = (vpn ) >> (lvl * PAGE_MAP_BITS);
last[lvl] = (vpn+npages-1) >> (lvl * PAGE_MAP_BITS);
@ -92,41 +86,12 @@ int page_map(size_t viraddr, size_t phyaddr, size_t npages, size_t bits)
spinlock_lock(&kslock);
/* We start now iterating through the entries
* beginning at the root table (PGD) */
/* Start iterating through the entries
* beginning at the root table (PGD or PML4) */
for (lvl=PAGE_LEVELS-1; lvl>=0; lvl--) {
for (vpn=first[lvl]; vpn<=last[lvl]; vpn++) {
if (lvl) { /* PML4, PDPT, PGD */
if (self[lvl][vpn] & PG_PRESENT) {
/* There already an existing table which only allows
* kernel accesses. We need to copy the table to create
* private copy for the user space process */
if (!(self[lvl][vpn] & PG_USER) && (bits & PG_USER)) {
size_t phyaddr = get_pages(1);
if (BUILTIN_EXPECT(!phyaddr, 0)) {
spinlock_unlock(&kslock);
return -ENOMEM;
}
atomic_int32_inc(&current_task->user_usage);
/* Copy old table contents to new one.
* We temporarily use page zero (PAGE_TMP) for this
* by mapping the new table to this address. */
page_map(PAGE_TMP, phyaddr, 1, PG_RW | PG_PRESENT);
memcpy((void *) PAGE_TMP, CHILD(self, lvl, vpn), PAGE_SIZE);
/* Update table by replacing address and altering flags */
self[lvl][vpn] &= ~(PAGE_MASK | PG_GLOBAL);
self[lvl][vpn] |= phyaddr | PG_USER;
/* We only need to flush the self-mapped table.
* TLB entries mapped by this table remain valid
* because we only made an identical copy. */
tlb_flush_one_page((size_t) CHILD(self, lvl, vpn));
}
}
else {
if (!(self[lvl][vpn] & PG_PRESENT)) {
/* There's no table available which covers the region.
* Therefore we need to create a new empty table. */
size_t phyaddr = get_pages(1);
@ -167,8 +132,10 @@ int page_unmap(size_t viraddr, size_t npages)
spinlock_lock(&kslock);
/* Start iterating through the entries.
* Only the PGT entries are removed. Tables remain allocated. */
for (vpn=start; vpn<end; vpn++)
self[0][vpn] = 0;
self[0][vpn] = 0;
spinlock_unlock(&kslock);
@ -251,10 +218,13 @@ void page_fault_handler(struct state *s)
{
size_t viraddr = read_cr2();
kprintf("Page Fault Exception (%d) at cs:ip = %#x:%#lx, address = %#lx\n",
s->int_no, s->cs, s->eip, viraddr);
outportb(0x20, 0x20); /** @todo: do we need this? */
kprintf("Page Fault Exception (%d) at cs:ip = %#x:%#lx, task = %u, addr = %#lx, error = %#x [ %s %s %s %s %s ]\n",
s->int_no, s->cs, s->eip, current_task->id, viraddr, s->error,
(s->error & 0x4) ? "user" : "supervisor",
(s->error & 0x10) ? "instruction" : "data",
(s->error & 0x2) ? "write" : ((s->error & 0x10) ? "fetch" : "read"),
(s->error & 0x1) ? "protection" : "not present",
(s->error & 0x8) ? "reserved bit" : "\b");
while(1) HALT;
}
@ -264,21 +234,21 @@ int page_init()
size_t addr, npages;
int i;
// replace default pagefault handler
/* Replace default pagefault handler */
irq_uninstall_handler(14);
irq_install_handler(14, page_fault_handler);
// map kernel
/* Map kernel */
addr = (size_t) &kernel_start;
npages = PAGE_FLOOR((size_t) &kernel_end - (size_t) &kernel_start) >> PAGE_BITS;
page_map(addr, addr, npages, PG_PRESENT | PG_RW | PG_GLOBAL);
#ifdef CONFIG_VGA
// map video memory
/* Map video memory */
page_map(VIDEO_MEM_ADDR, VIDEO_MEM_ADDR, 1, PG_PRESENT | PG_RW | PG_PCD);
#endif
// map multiboot information and modules
/* Map multiboot information and modules */
if (mb_info) {
addr = (size_t) mb_info & PAGE_MASK;
npages = PAGE_FLOOR(sizeof(*mb_info)) >> PAGE_BITS;
@ -298,7 +268,7 @@ int page_init()
}
}
// unmap all (identity mapped) pages with PG_BOOT flag in first PGT (boot_pgt)
/* Unmap bootstrap identity paging (see entry.asm, PG_BOOT) */
for (i=0; i<PAGE_MAP_ENTRIES; i++) {
if (self[0][i] & PG_BOOT) {
self[0][i] = 0;

7
debug.gdb Normal file
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@ -0,0 +1,7 @@
# Constant part of the script
symbol-file eduos.sym
target remote localhost:1234
set architecture i386
break main
continue

View file

@ -52,9 +52,9 @@ extern char __BUILD_DATE;
extern char __BUILD_TIME;
/* Page frame counters */
atomic_int32_t total_pages;
atomic_int32_t total_allocated_pages;
atomic_int32_t total_available_pages;
extern atomic_int32_t total_pages;
extern atomic_int32_t total_allocated_pages;
extern atomic_int32_t total_available_pages;
static void userfoo(void* arg)
{