b11b533427
Introduce user_mode to replace the two variables switch_amode and s390_noexec. There are three valid combinations of the old values: 1) switch_amode == 0 && s390_noexec == 0 2) switch_amode == 1 && s390_noexec == 0 3) switch_amode == 1 && s390_noexec == 1 They get replaced by 1) user_mode == HOME_SPACE_MODE 2) user_mode == PRIMARY_SPACE_MODE 3) user_mode == SECONDARY_SPACE_MODE The new kernel parameter user_mode=[primary,secondary,home] lets you choose the address space mode the user space processes should use. In addition the CONFIG_S390_SWITCH_AMODE config option is removed. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
337 lines
8.4 KiB
C
337 lines
8.4 KiB
C
/*
|
|
* Copyright IBM Corp. 2007,2009
|
|
* Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
|
|
*/
|
|
|
|
#include <linux/sched.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/errno.h>
|
|
#include <linux/mm.h>
|
|
#include <linux/swap.h>
|
|
#include <linux/smp.h>
|
|
#include <linux/highmem.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/pagemap.h>
|
|
#include <linux/spinlock.h>
|
|
#include <linux/module.h>
|
|
#include <linux/quicklist.h>
|
|
|
|
#include <asm/system.h>
|
|
#include <asm/pgtable.h>
|
|
#include <asm/pgalloc.h>
|
|
#include <asm/tlb.h>
|
|
#include <asm/tlbflush.h>
|
|
#include <asm/mmu_context.h>
|
|
|
|
#ifndef CONFIG_64BIT
|
|
#define ALLOC_ORDER 1
|
|
#define TABLES_PER_PAGE 4
|
|
#define FRAG_MASK 15UL
|
|
#define SECOND_HALVES 10UL
|
|
|
|
void clear_table_pgstes(unsigned long *table)
|
|
{
|
|
clear_table(table, _PAGE_TYPE_EMPTY, PAGE_SIZE/4);
|
|
memset(table + 256, 0, PAGE_SIZE/4);
|
|
clear_table(table + 512, _PAGE_TYPE_EMPTY, PAGE_SIZE/4);
|
|
memset(table + 768, 0, PAGE_SIZE/4);
|
|
}
|
|
|
|
#else
|
|
#define ALLOC_ORDER 2
|
|
#define TABLES_PER_PAGE 2
|
|
#define FRAG_MASK 3UL
|
|
#define SECOND_HALVES 2UL
|
|
|
|
void clear_table_pgstes(unsigned long *table)
|
|
{
|
|
clear_table(table, _PAGE_TYPE_EMPTY, PAGE_SIZE/2);
|
|
memset(table + 256, 0, PAGE_SIZE/2);
|
|
}
|
|
|
|
#endif
|
|
|
|
unsigned long VMALLOC_START = VMALLOC_END - VMALLOC_SIZE;
|
|
EXPORT_SYMBOL(VMALLOC_START);
|
|
|
|
static int __init parse_vmalloc(char *arg)
|
|
{
|
|
if (!arg)
|
|
return -EINVAL;
|
|
VMALLOC_START = (VMALLOC_END - memparse(arg, &arg)) & PAGE_MASK;
|
|
return 0;
|
|
}
|
|
early_param("vmalloc", parse_vmalloc);
|
|
|
|
unsigned long *crst_table_alloc(struct mm_struct *mm, int noexec)
|
|
{
|
|
struct page *page = alloc_pages(GFP_KERNEL, ALLOC_ORDER);
|
|
|
|
if (!page)
|
|
return NULL;
|
|
page->index = 0;
|
|
if (noexec) {
|
|
struct page *shadow = alloc_pages(GFP_KERNEL, ALLOC_ORDER);
|
|
if (!shadow) {
|
|
__free_pages(page, ALLOC_ORDER);
|
|
return NULL;
|
|
}
|
|
page->index = page_to_phys(shadow);
|
|
}
|
|
spin_lock(&mm->context.list_lock);
|
|
list_add(&page->lru, &mm->context.crst_list);
|
|
spin_unlock(&mm->context.list_lock);
|
|
return (unsigned long *) page_to_phys(page);
|
|
}
|
|
|
|
void crst_table_free(struct mm_struct *mm, unsigned long *table)
|
|
{
|
|
unsigned long *shadow = get_shadow_table(table);
|
|
struct page *page = virt_to_page(table);
|
|
|
|
spin_lock(&mm->context.list_lock);
|
|
list_del(&page->lru);
|
|
spin_unlock(&mm->context.list_lock);
|
|
if (shadow)
|
|
free_pages((unsigned long) shadow, ALLOC_ORDER);
|
|
free_pages((unsigned long) table, ALLOC_ORDER);
|
|
}
|
|
|
|
#ifdef CONFIG_64BIT
|
|
int crst_table_upgrade(struct mm_struct *mm, unsigned long limit)
|
|
{
|
|
unsigned long *table, *pgd;
|
|
unsigned long entry;
|
|
|
|
BUG_ON(limit > (1UL << 53));
|
|
repeat:
|
|
table = crst_table_alloc(mm, mm->context.noexec);
|
|
if (!table)
|
|
return -ENOMEM;
|
|
spin_lock(&mm->page_table_lock);
|
|
if (mm->context.asce_limit < limit) {
|
|
pgd = (unsigned long *) mm->pgd;
|
|
if (mm->context.asce_limit <= (1UL << 31)) {
|
|
entry = _REGION3_ENTRY_EMPTY;
|
|
mm->context.asce_limit = 1UL << 42;
|
|
mm->context.asce_bits = _ASCE_TABLE_LENGTH |
|
|
_ASCE_USER_BITS |
|
|
_ASCE_TYPE_REGION3;
|
|
} else {
|
|
entry = _REGION2_ENTRY_EMPTY;
|
|
mm->context.asce_limit = 1UL << 53;
|
|
mm->context.asce_bits = _ASCE_TABLE_LENGTH |
|
|
_ASCE_USER_BITS |
|
|
_ASCE_TYPE_REGION2;
|
|
}
|
|
crst_table_init(table, entry);
|
|
pgd_populate(mm, (pgd_t *) table, (pud_t *) pgd);
|
|
mm->pgd = (pgd_t *) table;
|
|
mm->task_size = mm->context.asce_limit;
|
|
table = NULL;
|
|
}
|
|
spin_unlock(&mm->page_table_lock);
|
|
if (table)
|
|
crst_table_free(mm, table);
|
|
if (mm->context.asce_limit < limit)
|
|
goto repeat;
|
|
update_mm(mm, current);
|
|
return 0;
|
|
}
|
|
|
|
void crst_table_downgrade(struct mm_struct *mm, unsigned long limit)
|
|
{
|
|
pgd_t *pgd;
|
|
|
|
if (mm->context.asce_limit <= limit)
|
|
return;
|
|
__tlb_flush_mm(mm);
|
|
while (mm->context.asce_limit > limit) {
|
|
pgd = mm->pgd;
|
|
switch (pgd_val(*pgd) & _REGION_ENTRY_TYPE_MASK) {
|
|
case _REGION_ENTRY_TYPE_R2:
|
|
mm->context.asce_limit = 1UL << 42;
|
|
mm->context.asce_bits = _ASCE_TABLE_LENGTH |
|
|
_ASCE_USER_BITS |
|
|
_ASCE_TYPE_REGION3;
|
|
break;
|
|
case _REGION_ENTRY_TYPE_R3:
|
|
mm->context.asce_limit = 1UL << 31;
|
|
mm->context.asce_bits = _ASCE_TABLE_LENGTH |
|
|
_ASCE_USER_BITS |
|
|
_ASCE_TYPE_SEGMENT;
|
|
break;
|
|
default:
|
|
BUG();
|
|
}
|
|
mm->pgd = (pgd_t *) (pgd_val(*pgd) & _REGION_ENTRY_ORIGIN);
|
|
mm->task_size = mm->context.asce_limit;
|
|
crst_table_free(mm, (unsigned long *) pgd);
|
|
}
|
|
update_mm(mm, current);
|
|
}
|
|
#endif
|
|
|
|
/*
|
|
* page table entry allocation/free routines.
|
|
*/
|
|
unsigned long *page_table_alloc(struct mm_struct *mm)
|
|
{
|
|
struct page *page;
|
|
unsigned long *table;
|
|
unsigned long bits;
|
|
|
|
bits = (mm->context.noexec || mm->context.has_pgste) ? 3UL : 1UL;
|
|
spin_lock(&mm->context.list_lock);
|
|
page = NULL;
|
|
if (!list_empty(&mm->context.pgtable_list)) {
|
|
page = list_first_entry(&mm->context.pgtable_list,
|
|
struct page, lru);
|
|
if ((page->flags & FRAG_MASK) == ((1UL << TABLES_PER_PAGE) - 1))
|
|
page = NULL;
|
|
}
|
|
if (!page) {
|
|
spin_unlock(&mm->context.list_lock);
|
|
page = alloc_page(GFP_KERNEL|__GFP_REPEAT);
|
|
if (!page)
|
|
return NULL;
|
|
pgtable_page_ctor(page);
|
|
page->flags &= ~FRAG_MASK;
|
|
table = (unsigned long *) page_to_phys(page);
|
|
if (mm->context.has_pgste)
|
|
clear_table_pgstes(table);
|
|
else
|
|
clear_table(table, _PAGE_TYPE_EMPTY, PAGE_SIZE);
|
|
spin_lock(&mm->context.list_lock);
|
|
list_add(&page->lru, &mm->context.pgtable_list);
|
|
}
|
|
table = (unsigned long *) page_to_phys(page);
|
|
while (page->flags & bits) {
|
|
table += 256;
|
|
bits <<= 1;
|
|
}
|
|
page->flags |= bits;
|
|
if ((page->flags & FRAG_MASK) == ((1UL << TABLES_PER_PAGE) - 1))
|
|
list_move_tail(&page->lru, &mm->context.pgtable_list);
|
|
spin_unlock(&mm->context.list_lock);
|
|
return table;
|
|
}
|
|
|
|
void page_table_free(struct mm_struct *mm, unsigned long *table)
|
|
{
|
|
struct page *page;
|
|
unsigned long bits;
|
|
|
|
bits = (mm->context.noexec || mm->context.has_pgste) ? 3UL : 1UL;
|
|
bits <<= (__pa(table) & (PAGE_SIZE - 1)) / 256 / sizeof(unsigned long);
|
|
page = pfn_to_page(__pa(table) >> PAGE_SHIFT);
|
|
spin_lock(&mm->context.list_lock);
|
|
page->flags ^= bits;
|
|
if (page->flags & FRAG_MASK) {
|
|
/* Page now has some free pgtable fragments. */
|
|
list_move(&page->lru, &mm->context.pgtable_list);
|
|
page = NULL;
|
|
} else
|
|
/* All fragments of the 4K page have been freed. */
|
|
list_del(&page->lru);
|
|
spin_unlock(&mm->context.list_lock);
|
|
if (page) {
|
|
pgtable_page_dtor(page);
|
|
__free_page(page);
|
|
}
|
|
}
|
|
|
|
void disable_noexec(struct mm_struct *mm, struct task_struct *tsk)
|
|
{
|
|
struct page *page;
|
|
|
|
spin_lock(&mm->context.list_lock);
|
|
/* Free shadow region and segment tables. */
|
|
list_for_each_entry(page, &mm->context.crst_list, lru)
|
|
if (page->index) {
|
|
free_pages((unsigned long) page->index, ALLOC_ORDER);
|
|
page->index = 0;
|
|
}
|
|
/* "Free" second halves of page tables. */
|
|
list_for_each_entry(page, &mm->context.pgtable_list, lru)
|
|
page->flags &= ~SECOND_HALVES;
|
|
spin_unlock(&mm->context.list_lock);
|
|
mm->context.noexec = 0;
|
|
update_mm(mm, tsk);
|
|
}
|
|
|
|
/*
|
|
* switch on pgstes for its userspace process (for kvm)
|
|
*/
|
|
int s390_enable_sie(void)
|
|
{
|
|
struct task_struct *tsk = current;
|
|
struct mm_struct *mm, *old_mm;
|
|
|
|
/* Do we have switched amode? If no, we cannot do sie */
|
|
if (user_mode == HOME_SPACE_MODE)
|
|
return -EINVAL;
|
|
|
|
/* Do we have pgstes? if yes, we are done */
|
|
if (tsk->mm->context.has_pgste)
|
|
return 0;
|
|
|
|
/* lets check if we are allowed to replace the mm */
|
|
task_lock(tsk);
|
|
if (!tsk->mm || atomic_read(&tsk->mm->mm_users) > 1 ||
|
|
#ifdef CONFIG_AIO
|
|
!hlist_empty(&tsk->mm->ioctx_list) ||
|
|
#endif
|
|
tsk->mm != tsk->active_mm) {
|
|
task_unlock(tsk);
|
|
return -EINVAL;
|
|
}
|
|
task_unlock(tsk);
|
|
|
|
/* we copy the mm and let dup_mm create the page tables with_pgstes */
|
|
tsk->mm->context.alloc_pgste = 1;
|
|
mm = dup_mm(tsk);
|
|
tsk->mm->context.alloc_pgste = 0;
|
|
if (!mm)
|
|
return -ENOMEM;
|
|
|
|
/* Now lets check again if something happened */
|
|
task_lock(tsk);
|
|
if (!tsk->mm || atomic_read(&tsk->mm->mm_users) > 1 ||
|
|
#ifdef CONFIG_AIO
|
|
!hlist_empty(&tsk->mm->ioctx_list) ||
|
|
#endif
|
|
tsk->mm != tsk->active_mm) {
|
|
mmput(mm);
|
|
task_unlock(tsk);
|
|
return -EINVAL;
|
|
}
|
|
|
|
/* ok, we are alone. No ptrace, no threads, etc. */
|
|
old_mm = tsk->mm;
|
|
tsk->mm = tsk->active_mm = mm;
|
|
preempt_disable();
|
|
update_mm(mm, tsk);
|
|
cpumask_set_cpu(smp_processor_id(), mm_cpumask(mm));
|
|
preempt_enable();
|
|
task_unlock(tsk);
|
|
mmput(old_mm);
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(s390_enable_sie);
|
|
|
|
#if defined(CONFIG_DEBUG_PAGEALLOC) && defined(CONFIG_HIBERNATION)
|
|
bool kernel_page_present(struct page *page)
|
|
{
|
|
unsigned long addr;
|
|
int cc;
|
|
|
|
addr = page_to_phys(page);
|
|
asm volatile(
|
|
" lra %1,0(%1)\n"
|
|
" ipm %0\n"
|
|
" srl %0,28"
|
|
: "=d" (cc), "+a" (addr) : : "cc");
|
|
return cc == 0;
|
|
}
|
|
#endif /* CONFIG_HIBERNATION && CONFIG_DEBUG_PAGEALLOC */
|