448 lines
13 KiB
C
448 lines
13 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
#include <linux/sched/task.h>
|
|
#include <linux/pgtable.h>
|
|
#include <linux/kasan.h>
|
|
#include <asm/pgalloc.h>
|
|
#include <asm/facility.h>
|
|
#include <asm/sections.h>
|
|
#include <asm/physmem_info.h>
|
|
#include <asm/maccess.h>
|
|
#include <asm/abs_lowcore.h>
|
|
#include "decompressor.h"
|
|
#include "boot.h"
|
|
|
|
unsigned long __bootdata_preserved(s390_invalid_asce);
|
|
|
|
#ifdef CONFIG_PROC_FS
|
|
atomic_long_t __bootdata_preserved(direct_pages_count[PG_DIRECT_MAP_MAX]);
|
|
#endif
|
|
|
|
#define init_mm (*(struct mm_struct *)vmlinux.init_mm_off)
|
|
#define swapper_pg_dir vmlinux.swapper_pg_dir_off
|
|
#define invalid_pg_dir vmlinux.invalid_pg_dir_off
|
|
|
|
enum populate_mode {
|
|
POPULATE_NONE,
|
|
POPULATE_DIRECT,
|
|
POPULATE_ABS_LOWCORE,
|
|
#ifdef CONFIG_KASAN
|
|
POPULATE_KASAN_MAP_SHADOW,
|
|
POPULATE_KASAN_ZERO_SHADOW,
|
|
POPULATE_KASAN_SHALLOW
|
|
#endif
|
|
};
|
|
|
|
static void pgtable_populate(unsigned long addr, unsigned long end, enum populate_mode mode);
|
|
|
|
#ifdef CONFIG_KASAN
|
|
|
|
#define kasan_early_shadow_page vmlinux.kasan_early_shadow_page_off
|
|
#define kasan_early_shadow_pte ((pte_t *)vmlinux.kasan_early_shadow_pte_off)
|
|
#define kasan_early_shadow_pmd ((pmd_t *)vmlinux.kasan_early_shadow_pmd_off)
|
|
#define kasan_early_shadow_pud ((pud_t *)vmlinux.kasan_early_shadow_pud_off)
|
|
#define kasan_early_shadow_p4d ((p4d_t *)vmlinux.kasan_early_shadow_p4d_off)
|
|
#define __sha(x) ((unsigned long)kasan_mem_to_shadow((void *)x))
|
|
|
|
static pte_t pte_z;
|
|
|
|
static inline void kasan_populate(unsigned long start, unsigned long end, enum populate_mode mode)
|
|
{
|
|
start = PAGE_ALIGN_DOWN(__sha(start));
|
|
end = PAGE_ALIGN(__sha(end));
|
|
pgtable_populate(start, end, mode);
|
|
}
|
|
|
|
static void kasan_populate_shadow(void)
|
|
{
|
|
pmd_t pmd_z = __pmd(__pa(kasan_early_shadow_pte) | _SEGMENT_ENTRY);
|
|
pud_t pud_z = __pud(__pa(kasan_early_shadow_pmd) | _REGION3_ENTRY);
|
|
p4d_t p4d_z = __p4d(__pa(kasan_early_shadow_pud) | _REGION2_ENTRY);
|
|
unsigned long untracked_end;
|
|
unsigned long start, end;
|
|
int i;
|
|
|
|
pte_z = __pte(__pa(kasan_early_shadow_page) | pgprot_val(PAGE_KERNEL_RO));
|
|
if (!machine.has_nx)
|
|
pte_z = clear_pte_bit(pte_z, __pgprot(_PAGE_NOEXEC));
|
|
crst_table_init((unsigned long *)kasan_early_shadow_p4d, p4d_val(p4d_z));
|
|
crst_table_init((unsigned long *)kasan_early_shadow_pud, pud_val(pud_z));
|
|
crst_table_init((unsigned long *)kasan_early_shadow_pmd, pmd_val(pmd_z));
|
|
memset64((u64 *)kasan_early_shadow_pte, pte_val(pte_z), PTRS_PER_PTE);
|
|
|
|
/*
|
|
* Current memory layout:
|
|
* +- 0 -------------+ +- shadow start -+
|
|
* |1:1 ident mapping| /|1/8 of ident map|
|
|
* | | / | |
|
|
* +-end of ident map+ / +----------------+
|
|
* | ... gap ... | / | kasan |
|
|
* | | / | zero page |
|
|
* +- vmalloc area -+ / | mapping |
|
|
* | vmalloc_size | / | (untracked) |
|
|
* +- modules vaddr -+ / +----------------+
|
|
* | 2Gb |/ | unmapped | allocated per module
|
|
* +- shadow start -+ +----------------+
|
|
* | 1/8 addr space | | zero pg mapping| (untracked)
|
|
* +- shadow end ----+---------+- shadow end ---+
|
|
*
|
|
* Current memory layout (KASAN_VMALLOC):
|
|
* +- 0 -------------+ +- shadow start -+
|
|
* |1:1 ident mapping| /|1/8 of ident map|
|
|
* | | / | |
|
|
* +-end of ident map+ / +----------------+
|
|
* | ... gap ... | / | kasan zero page| (untracked)
|
|
* | | / | mapping |
|
|
* +- vmalloc area -+ / +----------------+
|
|
* | vmalloc_size | / |shallow populate|
|
|
* +- modules vaddr -+ / +----------------+
|
|
* | 2Gb |/ |shallow populate|
|
|
* +- shadow start -+ +----------------+
|
|
* | 1/8 addr space | | zero pg mapping| (untracked)
|
|
* +- shadow end ----+---------+- shadow end ---+
|
|
*/
|
|
|
|
for_each_physmem_usable_range(i, &start, &end)
|
|
kasan_populate(start, end, POPULATE_KASAN_MAP_SHADOW);
|
|
if (IS_ENABLED(CONFIG_KASAN_VMALLOC)) {
|
|
untracked_end = VMALLOC_START;
|
|
/* shallowly populate kasan shadow for vmalloc and modules */
|
|
kasan_populate(VMALLOC_START, MODULES_END, POPULATE_KASAN_SHALLOW);
|
|
} else {
|
|
untracked_end = MODULES_VADDR;
|
|
}
|
|
/* populate kasan shadow for untracked memory */
|
|
kasan_populate(ident_map_size, untracked_end, POPULATE_KASAN_ZERO_SHADOW);
|
|
kasan_populate(MODULES_END, _REGION1_SIZE, POPULATE_KASAN_ZERO_SHADOW);
|
|
}
|
|
|
|
static bool kasan_pgd_populate_zero_shadow(pgd_t *pgd, unsigned long addr,
|
|
unsigned long end, enum populate_mode mode)
|
|
{
|
|
if (mode == POPULATE_KASAN_ZERO_SHADOW &&
|
|
IS_ALIGNED(addr, PGDIR_SIZE) && end - addr >= PGDIR_SIZE) {
|
|
pgd_populate(&init_mm, pgd, kasan_early_shadow_p4d);
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
static bool kasan_p4d_populate_zero_shadow(p4d_t *p4d, unsigned long addr,
|
|
unsigned long end, enum populate_mode mode)
|
|
{
|
|
if (mode == POPULATE_KASAN_ZERO_SHADOW &&
|
|
IS_ALIGNED(addr, P4D_SIZE) && end - addr >= P4D_SIZE) {
|
|
p4d_populate(&init_mm, p4d, kasan_early_shadow_pud);
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
static bool kasan_pud_populate_zero_shadow(pud_t *pud, unsigned long addr,
|
|
unsigned long end, enum populate_mode mode)
|
|
{
|
|
if (mode == POPULATE_KASAN_ZERO_SHADOW &&
|
|
IS_ALIGNED(addr, PUD_SIZE) && end - addr >= PUD_SIZE) {
|
|
pud_populate(&init_mm, pud, kasan_early_shadow_pmd);
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
static bool kasan_pmd_populate_zero_shadow(pmd_t *pmd, unsigned long addr,
|
|
unsigned long end, enum populate_mode mode)
|
|
{
|
|
if (mode == POPULATE_KASAN_ZERO_SHADOW &&
|
|
IS_ALIGNED(addr, PMD_SIZE) && end - addr >= PMD_SIZE) {
|
|
pmd_populate(&init_mm, pmd, kasan_early_shadow_pte);
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
static bool kasan_pte_populate_zero_shadow(pte_t *pte, enum populate_mode mode)
|
|
{
|
|
pte_t entry;
|
|
|
|
if (mode == POPULATE_KASAN_ZERO_SHADOW) {
|
|
set_pte(pte, pte_z);
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
#else
|
|
|
|
static inline void kasan_populate_shadow(void) {}
|
|
|
|
static inline bool kasan_pgd_populate_zero_shadow(pgd_t *pgd, unsigned long addr,
|
|
unsigned long end, enum populate_mode mode)
|
|
{
|
|
return false;
|
|
}
|
|
|
|
static inline bool kasan_p4d_populate_zero_shadow(p4d_t *p4d, unsigned long addr,
|
|
unsigned long end, enum populate_mode mode)
|
|
{
|
|
return false;
|
|
}
|
|
|
|
static inline bool kasan_pud_populate_zero_shadow(pud_t *pud, unsigned long addr,
|
|
unsigned long end, enum populate_mode mode)
|
|
{
|
|
return false;
|
|
}
|
|
|
|
static inline bool kasan_pmd_populate_zero_shadow(pmd_t *pmd, unsigned long addr,
|
|
unsigned long end, enum populate_mode mode)
|
|
{
|
|
return false;
|
|
}
|
|
|
|
static bool kasan_pte_populate_zero_shadow(pte_t *pte, enum populate_mode mode)
|
|
{
|
|
return false;
|
|
}
|
|
|
|
#endif
|
|
|
|
/*
|
|
* Mimic virt_to_kpte() in lack of init_mm symbol. Skip pmd NULL check though.
|
|
*/
|
|
static inline pte_t *__virt_to_kpte(unsigned long va)
|
|
{
|
|
return pte_offset_kernel(pmd_offset(pud_offset(p4d_offset(pgd_offset_k(va), va), va), va), va);
|
|
}
|
|
|
|
static void *boot_crst_alloc(unsigned long val)
|
|
{
|
|
unsigned long size = PAGE_SIZE << CRST_ALLOC_ORDER;
|
|
unsigned long *table;
|
|
|
|
table = (unsigned long *)physmem_alloc_top_down(RR_VMEM, size, size);
|
|
crst_table_init(table, val);
|
|
return table;
|
|
}
|
|
|
|
static pte_t *boot_pte_alloc(void)
|
|
{
|
|
static void *pte_leftover;
|
|
pte_t *pte;
|
|
|
|
/*
|
|
* handling pte_leftovers this way helps to avoid memory fragmentation
|
|
* during POPULATE_KASAN_MAP_SHADOW when EDAT is off
|
|
*/
|
|
if (!pte_leftover) {
|
|
pte_leftover = (void *)physmem_alloc_top_down(RR_VMEM, PAGE_SIZE, PAGE_SIZE);
|
|
pte = pte_leftover + _PAGE_TABLE_SIZE;
|
|
} else {
|
|
pte = pte_leftover;
|
|
pte_leftover = NULL;
|
|
}
|
|
|
|
memset64((u64 *)pte, _PAGE_INVALID, PTRS_PER_PTE);
|
|
return pte;
|
|
}
|
|
|
|
static unsigned long _pa(unsigned long addr, unsigned long size, enum populate_mode mode)
|
|
{
|
|
switch (mode) {
|
|
case POPULATE_NONE:
|
|
return -1;
|
|
case POPULATE_DIRECT:
|
|
return addr;
|
|
case POPULATE_ABS_LOWCORE:
|
|
return __abs_lowcore_pa(addr);
|
|
#ifdef CONFIG_KASAN
|
|
case POPULATE_KASAN_MAP_SHADOW:
|
|
addr = physmem_alloc_top_down(RR_VMEM, size, size);
|
|
memset((void *)addr, 0, size);
|
|
return addr;
|
|
#endif
|
|
default:
|
|
return -1;
|
|
}
|
|
}
|
|
|
|
static bool can_large_pud(pud_t *pu_dir, unsigned long addr, unsigned long end)
|
|
{
|
|
return machine.has_edat2 &&
|
|
IS_ALIGNED(addr, PUD_SIZE) && (end - addr) >= PUD_SIZE;
|
|
}
|
|
|
|
static bool can_large_pmd(pmd_t *pm_dir, unsigned long addr, unsigned long end)
|
|
{
|
|
return machine.has_edat1 &&
|
|
IS_ALIGNED(addr, PMD_SIZE) && (end - addr) >= PMD_SIZE;
|
|
}
|
|
|
|
static void pgtable_pte_populate(pmd_t *pmd, unsigned long addr, unsigned long end,
|
|
enum populate_mode mode)
|
|
{
|
|
unsigned long pages = 0;
|
|
pte_t *pte, entry;
|
|
|
|
pte = pte_offset_kernel(pmd, addr);
|
|
for (; addr < end; addr += PAGE_SIZE, pte++) {
|
|
if (pte_none(*pte)) {
|
|
if (kasan_pte_populate_zero_shadow(pte, mode))
|
|
continue;
|
|
entry = __pte(_pa(addr, PAGE_SIZE, mode));
|
|
entry = set_pte_bit(entry, PAGE_KERNEL_EXEC);
|
|
set_pte(pte, entry);
|
|
pages++;
|
|
}
|
|
}
|
|
if (mode == POPULATE_DIRECT)
|
|
update_page_count(PG_DIRECT_MAP_4K, pages);
|
|
}
|
|
|
|
static void pgtable_pmd_populate(pud_t *pud, unsigned long addr, unsigned long end,
|
|
enum populate_mode mode)
|
|
{
|
|
unsigned long next, pages = 0;
|
|
pmd_t *pmd, entry;
|
|
pte_t *pte;
|
|
|
|
pmd = pmd_offset(pud, addr);
|
|
for (; addr < end; addr = next, pmd++) {
|
|
next = pmd_addr_end(addr, end);
|
|
if (pmd_none(*pmd)) {
|
|
if (kasan_pmd_populate_zero_shadow(pmd, addr, next, mode))
|
|
continue;
|
|
if (can_large_pmd(pmd, addr, next)) {
|
|
entry = __pmd(_pa(addr, _SEGMENT_SIZE, mode));
|
|
entry = set_pmd_bit(entry, SEGMENT_KERNEL_EXEC);
|
|
set_pmd(pmd, entry);
|
|
pages++;
|
|
continue;
|
|
}
|
|
pte = boot_pte_alloc();
|
|
pmd_populate(&init_mm, pmd, pte);
|
|
} else if (pmd_large(*pmd)) {
|
|
continue;
|
|
}
|
|
pgtable_pte_populate(pmd, addr, next, mode);
|
|
}
|
|
if (mode == POPULATE_DIRECT)
|
|
update_page_count(PG_DIRECT_MAP_1M, pages);
|
|
}
|
|
|
|
static void pgtable_pud_populate(p4d_t *p4d, unsigned long addr, unsigned long end,
|
|
enum populate_mode mode)
|
|
{
|
|
unsigned long next, pages = 0;
|
|
pud_t *pud, entry;
|
|
pmd_t *pmd;
|
|
|
|
pud = pud_offset(p4d, addr);
|
|
for (; addr < end; addr = next, pud++) {
|
|
next = pud_addr_end(addr, end);
|
|
if (pud_none(*pud)) {
|
|
if (kasan_pud_populate_zero_shadow(pud, addr, next, mode))
|
|
continue;
|
|
if (can_large_pud(pud, addr, next)) {
|
|
entry = __pud(_pa(addr, _REGION3_SIZE, mode));
|
|
entry = set_pud_bit(entry, REGION3_KERNEL_EXEC);
|
|
set_pud(pud, entry);
|
|
pages++;
|
|
continue;
|
|
}
|
|
pmd = boot_crst_alloc(_SEGMENT_ENTRY_EMPTY);
|
|
pud_populate(&init_mm, pud, pmd);
|
|
} else if (pud_large(*pud)) {
|
|
continue;
|
|
}
|
|
pgtable_pmd_populate(pud, addr, next, mode);
|
|
}
|
|
if (mode == POPULATE_DIRECT)
|
|
update_page_count(PG_DIRECT_MAP_2G, pages);
|
|
}
|
|
|
|
static void pgtable_p4d_populate(pgd_t *pgd, unsigned long addr, unsigned long end,
|
|
enum populate_mode mode)
|
|
{
|
|
unsigned long next;
|
|
p4d_t *p4d;
|
|
pud_t *pud;
|
|
|
|
p4d = p4d_offset(pgd, addr);
|
|
for (; addr < end; addr = next, p4d++) {
|
|
next = p4d_addr_end(addr, end);
|
|
if (p4d_none(*p4d)) {
|
|
if (kasan_p4d_populate_zero_shadow(p4d, addr, next, mode))
|
|
continue;
|
|
pud = boot_crst_alloc(_REGION3_ENTRY_EMPTY);
|
|
p4d_populate(&init_mm, p4d, pud);
|
|
}
|
|
pgtable_pud_populate(p4d, addr, next, mode);
|
|
}
|
|
}
|
|
|
|
static void pgtable_populate(unsigned long addr, unsigned long end, enum populate_mode mode)
|
|
{
|
|
unsigned long next;
|
|
pgd_t *pgd;
|
|
p4d_t *p4d;
|
|
|
|
pgd = pgd_offset(&init_mm, addr);
|
|
for (; addr < end; addr = next, pgd++) {
|
|
next = pgd_addr_end(addr, end);
|
|
if (pgd_none(*pgd)) {
|
|
if (kasan_pgd_populate_zero_shadow(pgd, addr, next, mode))
|
|
continue;
|
|
p4d = boot_crst_alloc(_REGION2_ENTRY_EMPTY);
|
|
pgd_populate(&init_mm, pgd, p4d);
|
|
}
|
|
#ifdef CONFIG_KASAN
|
|
if (mode == POPULATE_KASAN_SHALLOW)
|
|
continue;
|
|
#endif
|
|
pgtable_p4d_populate(pgd, addr, next, mode);
|
|
}
|
|
}
|
|
|
|
void setup_vmem(unsigned long asce_limit)
|
|
{
|
|
unsigned long start, end;
|
|
unsigned long asce_type;
|
|
unsigned long asce_bits;
|
|
int i;
|
|
|
|
if (asce_limit == _REGION1_SIZE) {
|
|
asce_type = _REGION2_ENTRY_EMPTY;
|
|
asce_bits = _ASCE_TYPE_REGION2 | _ASCE_TABLE_LENGTH;
|
|
} else {
|
|
asce_type = _REGION3_ENTRY_EMPTY;
|
|
asce_bits = _ASCE_TYPE_REGION3 | _ASCE_TABLE_LENGTH;
|
|
}
|
|
s390_invalid_asce = invalid_pg_dir | _ASCE_TYPE_REGION3 | _ASCE_TABLE_LENGTH;
|
|
|
|
crst_table_init((unsigned long *)swapper_pg_dir, asce_type);
|
|
crst_table_init((unsigned long *)invalid_pg_dir, _REGION3_ENTRY_EMPTY);
|
|
|
|
/*
|
|
* To allow prefixing the lowcore must be mapped with 4KB pages.
|
|
* To prevent creation of a large page at address 0 first map
|
|
* the lowcore and create the identity mapping only afterwards.
|
|
*/
|
|
pgtable_populate(0, sizeof(struct lowcore), POPULATE_DIRECT);
|
|
for_each_physmem_usable_range(i, &start, &end)
|
|
pgtable_populate(start, end, POPULATE_DIRECT);
|
|
pgtable_populate(__abs_lowcore, __abs_lowcore + sizeof(struct lowcore),
|
|
POPULATE_ABS_LOWCORE);
|
|
pgtable_populate(__memcpy_real_area, __memcpy_real_area + PAGE_SIZE,
|
|
POPULATE_NONE);
|
|
memcpy_real_ptep = __virt_to_kpte(__memcpy_real_area);
|
|
|
|
kasan_populate_shadow();
|
|
|
|
S390_lowcore.kernel_asce = swapper_pg_dir | asce_bits;
|
|
S390_lowcore.user_asce = s390_invalid_asce;
|
|
|
|
__ctl_load(S390_lowcore.kernel_asce, 1, 1);
|
|
__ctl_load(S390_lowcore.user_asce, 7, 7);
|
|
__ctl_load(S390_lowcore.kernel_asce, 13, 13);
|
|
|
|
init_mm.context.asce = S390_lowcore.kernel_asce;
|
|
}
|