mirror of https://gitee.com/openkylin/linux.git
131 lines
3.3 KiB
C
131 lines
3.3 KiB
C
#define pr_fmt(fmt) "kasan: " fmt
|
|
#include <linux/bootmem.h>
|
|
#include <linux/kasan.h>
|
|
#include <linux/kdebug.h>
|
|
#include <linux/mm.h>
|
|
#include <linux/sched.h>
|
|
#include <linux/vmalloc.h>
|
|
|
|
#include <asm/tlbflush.h>
|
|
#include <asm/sections.h>
|
|
|
|
extern pgd_t early_level4_pgt[PTRS_PER_PGD];
|
|
extern struct range pfn_mapped[E820_X_MAX];
|
|
|
|
static int __init map_range(struct range *range)
|
|
{
|
|
unsigned long start;
|
|
unsigned long end;
|
|
|
|
start = (unsigned long)kasan_mem_to_shadow(pfn_to_kaddr(range->start));
|
|
end = (unsigned long)kasan_mem_to_shadow(pfn_to_kaddr(range->end));
|
|
|
|
/*
|
|
* end + 1 here is intentional. We check several shadow bytes in advance
|
|
* to slightly speed up fastpath. In some rare cases we could cross
|
|
* boundary of mapped shadow, so we just map some more here.
|
|
*/
|
|
return vmemmap_populate(start, end + 1, NUMA_NO_NODE);
|
|
}
|
|
|
|
static void __init clear_pgds(unsigned long start,
|
|
unsigned long end)
|
|
{
|
|
for (; start < end; start += PGDIR_SIZE)
|
|
pgd_clear(pgd_offset_k(start));
|
|
}
|
|
|
|
static void __init kasan_map_early_shadow(pgd_t *pgd)
|
|
{
|
|
int i;
|
|
unsigned long start = KASAN_SHADOW_START;
|
|
unsigned long end = KASAN_SHADOW_END;
|
|
|
|
for (i = pgd_index(start); start < end; i++) {
|
|
pgd[i] = __pgd(__pa_nodebug(kasan_zero_pud)
|
|
| _KERNPG_TABLE);
|
|
start += PGDIR_SIZE;
|
|
}
|
|
}
|
|
|
|
#ifdef CONFIG_KASAN_INLINE
|
|
static int kasan_die_handler(struct notifier_block *self,
|
|
unsigned long val,
|
|
void *data)
|
|
{
|
|
if (val == DIE_GPF) {
|
|
pr_emerg("CONFIG_KASAN_INLINE enabled");
|
|
pr_emerg("GPF could be caused by NULL-ptr deref or user memory access");
|
|
}
|
|
return NOTIFY_OK;
|
|
}
|
|
|
|
static struct notifier_block kasan_die_notifier = {
|
|
.notifier_call = kasan_die_handler,
|
|
};
|
|
#endif
|
|
|
|
void __init kasan_early_init(void)
|
|
{
|
|
int i;
|
|
pteval_t pte_val = __pa_nodebug(kasan_zero_page) | __PAGE_KERNEL;
|
|
pmdval_t pmd_val = __pa_nodebug(kasan_zero_pte) | _KERNPG_TABLE;
|
|
pudval_t pud_val = __pa_nodebug(kasan_zero_pmd) | _KERNPG_TABLE;
|
|
|
|
for (i = 0; i < PTRS_PER_PTE; i++)
|
|
kasan_zero_pte[i] = __pte(pte_val);
|
|
|
|
for (i = 0; i < PTRS_PER_PMD; i++)
|
|
kasan_zero_pmd[i] = __pmd(pmd_val);
|
|
|
|
for (i = 0; i < PTRS_PER_PUD; i++)
|
|
kasan_zero_pud[i] = __pud(pud_val);
|
|
|
|
kasan_map_early_shadow(early_level4_pgt);
|
|
kasan_map_early_shadow(init_level4_pgt);
|
|
}
|
|
|
|
void __init kasan_init(void)
|
|
{
|
|
int i;
|
|
|
|
#ifdef CONFIG_KASAN_INLINE
|
|
register_die_notifier(&kasan_die_notifier);
|
|
#endif
|
|
|
|
memcpy(early_level4_pgt, init_level4_pgt, sizeof(early_level4_pgt));
|
|
load_cr3(early_level4_pgt);
|
|
__flush_tlb_all();
|
|
|
|
clear_pgds(KASAN_SHADOW_START, KASAN_SHADOW_END);
|
|
|
|
kasan_populate_zero_shadow((void *)KASAN_SHADOW_START,
|
|
kasan_mem_to_shadow((void *)PAGE_OFFSET));
|
|
|
|
for (i = 0; i < E820_X_MAX; i++) {
|
|
if (pfn_mapped[i].end == 0)
|
|
break;
|
|
|
|
if (map_range(&pfn_mapped[i]))
|
|
panic("kasan: unable to allocate shadow!");
|
|
}
|
|
kasan_populate_zero_shadow(
|
|
kasan_mem_to_shadow((void *)PAGE_OFFSET + MAXMEM),
|
|
kasan_mem_to_shadow((void *)__START_KERNEL_map));
|
|
|
|
vmemmap_populate((unsigned long)kasan_mem_to_shadow(_stext),
|
|
(unsigned long)kasan_mem_to_shadow(_end),
|
|
NUMA_NO_NODE);
|
|
|
|
kasan_populate_zero_shadow(kasan_mem_to_shadow((void *)MODULES_END),
|
|
(void *)KASAN_SHADOW_END);
|
|
|
|
memset(kasan_zero_page, 0, PAGE_SIZE);
|
|
|
|
load_cr3(init_level4_pgt);
|
|
__flush_tlb_all();
|
|
init_task.kasan_depth = 0;
|
|
|
|
pr_info("Kernel address sanitizer initialized\n");
|
|
}
|