stv0g/eduOS
1
0
Fork 0
Code Issues Pull requests Releases Wiki Activity

removed userspace fork/kill support to separate branch

Browse source
This commit is contained in:
Steffen Vogel 2014-11-28 02:00:35 +01:00
parent b86e9d9a7d
commit b33107eef7
1 changed files with 1 additions and 103 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

104
arch/x86/mm/page.c
View file

@ -97,36 +97,7 @@ int page_map(size_t viraddr, size_t phyaddr, size_t npages, size_t bits)
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);
@ -175,79 +146,6 @@ int page_unmap(size_t viraddr, size_t npages)
return 0;
}
/* @todo: complete
int page_map_drop()
{
void traverse(int lvl, long vpn) {
kprintf("traverse(lvl=%d, vpn=%#lx)\n", lvl, vpn);
long stop;
for (stop=vpn+PAGE_MAP_ENTRIES; vpn<stop; vpn++) {
if (self[lvl][vpn] & PG_PRESENT) {
if (self[lvl][vpn] & PG_BOOT)
continue;
// ost-order traversal
if (lvl > 1)
traverse(lvl-1, vpn<<PAGE_MAP_BITS);
kprintf("%#lx, ", self[lvl][vpn] & PAGE_MASK);
//put_page(self[lvl][vpn] & PAGE_MASK);
atomic_int32_dec(&current_task->user_usage);
}
}
}
spinlock_irqsave_lock(&current_task->page_lock);
traverse(PAGE_LEVELS-1, 0);
spinlock_irqsave_unlock(&current_task->page_lock);
return 0;
}
int page_map_copy(size_t dest)
{
int traverse(int lvl, long vpn) {
long stop;
for (stop=vpn+PAGE_MAP_ENTRIES; vpn<stop; vpn++) {
if (self[lvl][vpn] & PG_PRESENT) {
size_t phyaddr = get_pages(1);
if (BUILTIN_EXPECT(phyaddr, 0))
return -ENOMEM;
new[lvl][vpn] = phyaddr;
new[lvl][vpn] |= self[lvl][vpn] & ~PAGE_MASK;
memcpy(CHILD(other, lvl, vpn), CHILD(self, lvl, vpn), PAGE_SIZE);
// pre-order traversal
if (lvl)
traverse(lvl-1, vpn<<PAGE_MAP_BITS);
}
}
return 0;
}
spinlock_lock(&kslock);
// create another temporary self-reference
self[PAGE_LEVELS-1][PAGE_MAP_ENTRIES-2] = dest | PG_PRESENT | PG_RW;
traverse(PAGE_LEVELS-1, 0);
// remove temporary self-reference
self[PAGE_LEVELS-1][PAGE_MAP_ENTRIES-2] = 0;
spinlock_unlock(&kslock);
return 0;
}*/
void page_fault_handler(struct state *s)
{
size_t viraddr = read_cr2();