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// SPDX-License-Identifier: GPL-2.0
#include <linux/kasan.h>
#include <linux/sched/task.h>
#include <linux/memblock.h>
#include <asm/pgalloc.h>
#include <asm/pgtable.h>
#include <asm/kasan.h>
#include <asm/mem_detect.h>
#include <asm/processor.h>
#include <asm/sclp.h>
#include <asm/facility.h>
#include <asm/sections.h>
#include <asm/setup.h>
static unsigned long segment_pos __initdata;
static unsigned long segment_low __initdata;
static unsigned long pgalloc_pos __initdata;
static unsigned long pgalloc_low __initdata;
static unsigned long pgalloc_freeable __initdata;
static bool has_edat __initdata;
static bool has_nx __initdata;
#define __sha(x) ((unsigned long)kasan_mem_to_shadow((void *)x))
static pgd_t early_pg_dir[PTRS_PER_PGD] __initdata __aligned(PAGE_SIZE);
static void __init kasan_early_panic(const char *reason)
{
sclp_early_printk("The Linux kernel failed to boot with the KernelAddressSanitizer:\n");
sclp_early_printk(reason);
disabled_wait(0);
}
static void * __init kasan_early_alloc_segment(void)
{
segment_pos -= _SEGMENT_SIZE;
if (segment_pos < segment_low)
kasan_early_panic("out of memory during initialisation\n");
return (void *)segment_pos;
}
static void * __init kasan_early_alloc_pages(unsigned int order)
{
pgalloc_pos -= (PAGE_SIZE << order);
if (pgalloc_pos < pgalloc_low)
kasan_early_panic("out of memory during initialisation\n");
return (void *)pgalloc_pos;
}
static void * __init kasan_early_crst_alloc(unsigned long val)
{
unsigned long *table;
table = kasan_early_alloc_pages(CRST_ALLOC_ORDER);
if (table)
crst_table_init(table, val);
return table;
}
static pte_t * __init kasan_early_pte_alloc(void)
{
static void *pte_leftover;
pte_t *pte;
BUILD_BUG_ON(_PAGE_TABLE_SIZE * 2 != PAGE_SIZE);
if (!pte_leftover) {
pte_leftover = kasan_early_alloc_pages(0);
pte = pte_leftover + _PAGE_TABLE_SIZE;
} else {
pte = pte_leftover;
pte_leftover = NULL;
}
memset64((u64 *)pte, _PAGE_INVALID, PTRS_PER_PTE);
return pte;
}
enum populate_mode {
POPULATE_ONE2ONE,
POPULATE_MAP,
POPULATE_ZERO_SHADOW
};
static void __init kasan_early_vmemmap_populate(unsigned long address,
unsigned long end,
enum populate_mode mode)
{
unsigned long pgt_prot_zero, pgt_prot, sgt_prot;
pgd_t *pg_dir;
p4d_t *p4_dir;
pud_t *pu_dir;
pmd_t *pm_dir;
pte_t *pt_dir;
pgt_prot_zero = pgprot_val(PAGE_KERNEL_RO);
if (!has_nx)
pgt_prot_zero &= ~_PAGE_NOEXEC;
pgt_prot = pgprot_val(PAGE_KERNEL_EXEC);
sgt_prot = pgprot_val(SEGMENT_KERNEL_EXEC);
while (address < end) {
pg_dir = pgd_offset_k(address);
if (pgd_none(*pg_dir)) {
if (mode == POPULATE_ZERO_SHADOW &&
IS_ALIGNED(address, PGDIR_SIZE) &&
end - address >= PGDIR_SIZE) {
pgd_populate(&init_mm, pg_dir,
kasan_early_shadow_p4d);
address = (address + PGDIR_SIZE) & PGDIR_MASK;
continue;
}
p4_dir = kasan_early_crst_alloc(_REGION2_ENTRY_EMPTY);
pgd_populate(&init_mm, pg_dir, p4_dir);
}
p4_dir = p4d_offset(pg_dir, address);
if (p4d_none(*p4_dir)) {
if (mode == POPULATE_ZERO_SHADOW &&
IS_ALIGNED(address, P4D_SIZE) &&
end - address >= P4D_SIZE) {
p4d_populate(&init_mm, p4_dir,
kasan_early_shadow_pud);
address = (address + P4D_SIZE) & P4D_MASK;
continue;
}
pu_dir = kasan_early_crst_alloc(_REGION3_ENTRY_EMPTY);
p4d_populate(&init_mm, p4_dir, pu_dir);
}
pu_dir = pud_offset(p4_dir, address);
if (pud_none(*pu_dir)) {
if (mode == POPULATE_ZERO_SHADOW &&
IS_ALIGNED(address, PUD_SIZE) &&
end - address >= PUD_SIZE) {
pud_populate(&init_mm, pu_dir,
kasan_early_shadow_pmd);
address = (address + PUD_SIZE) & PUD_MASK;
continue;
}
pm_dir = kasan_early_crst_alloc(_SEGMENT_ENTRY_EMPTY);
pud_populate(&init_mm, pu_dir, pm_dir);
}
pm_dir = pmd_offset(pu_dir, address);
if (pmd_none(*pm_dir)) {
if (mode == POPULATE_ZERO_SHADOW &&
IS_ALIGNED(address, PMD_SIZE) &&
end - address >= PMD_SIZE) {
pmd_populate(&init_mm, pm_dir,
kasan_early_shadow_pte);
address = (address + PMD_SIZE) & PMD_MASK;
continue;
}
/* the first megabyte of 1:1 is mapped with 4k pages */
if (has_edat && address && end - address >= PMD_SIZE &&
mode != POPULATE_ZERO_SHADOW) {
void *page;
if (mode == POPULATE_ONE2ONE) {
page = (void *)address;
} else {
page = kasan_early_alloc_segment();
memset(page, 0, _SEGMENT_SIZE);
}
pmd_val(*pm_dir) = __pa(page) | sgt_prot;
address = (address + PMD_SIZE) & PMD_MASK;
continue;
}
pt_dir = kasan_early_pte_alloc();
pmd_populate(&init_mm, pm_dir, pt_dir);
} else if (pmd_large(*pm_dir)) {
address = (address + PMD_SIZE) & PMD_MASK;
continue;
}
pt_dir = pte_offset_kernel(pm_dir, address);
if (pte_none(*pt_dir)) {
void *page;
switch (mode) {
case POPULATE_ONE2ONE:
page = (void *)address;
pte_val(*pt_dir) = __pa(page) | pgt_prot;
break;
case POPULATE_MAP:
page = kasan_early_alloc_pages(0);
memset(page, 0, PAGE_SIZE);
pte_val(*pt_dir) = __pa(page) | pgt_prot;
break;
case POPULATE_ZERO_SHADOW:
page = kasan_early_shadow_page;
pte_val(*pt_dir) = __pa(page) | pgt_prot_zero;
break;
}
}
address += PAGE_SIZE;
}
}
static void __init kasan_set_pgd(pgd_t *pgd, unsigned long asce_type)
{
unsigned long asce_bits;
asce_bits = asce_type | _ASCE_TABLE_LENGTH;
S390_lowcore.kernel_asce = (__pa(pgd) & PAGE_MASK) | asce_bits;
S390_lowcore.user_asce = S390_lowcore.kernel_asce;
__ctl_load(S390_lowcore.kernel_asce, 1, 1);
__ctl_load(S390_lowcore.kernel_asce, 7, 7);
__ctl_load(S390_lowcore.kernel_asce, 13, 13);
}
static void __init kasan_enable_dat(void)
{
psw_t psw;
psw.mask = __extract_psw();
psw_bits(psw).dat = 1;
psw_bits(psw).as = PSW_BITS_AS_HOME;
__load_psw_mask(psw.mask);
}
static void __init kasan_early_detect_facilities(void)
{
__stfle(S390_lowcore.stfle_fac_list,
ARRAY_SIZE(S390_lowcore.stfle_fac_list));
if (test_facility(8)) {
has_edat = true;
__ctl_set_bit(0, 23);
}
if (!noexec_disabled && test_facility(130)) {
has_nx = true;
__ctl_set_bit(0, 20);
}
}
static unsigned long __ini
|