100 lines
2.7 KiB
C
100 lines
2.7 KiB
C
|
/*
|
||
|
|
* Xtensa KASAN shadow map initialization
|
||
|
|
*
|
||
|
|
* This file is subject to the terms and conditions of the GNU General Public
|
||
|
|
* License. See the file "COPYING" in the main directory of this archive
|
||
|
|
* for more details.
|
||
|
|
*
|
||
|
|
* Copyright (C) 2017 Cadence Design Systems Inc.
|
||
|
|
*/
|
||
|
|
|
||
|
|
#include <linux/bootmem.h>
|
||
|
|
#include <linux/init_task.h>
|
||
|
|
#include <linux/kasan.h>
|
||
|
|
#include <linux/kernel.h>
|
||
|
|
#include <linux/memblock.h>
|
||
|
|
#include <asm/initialize_mmu.h>
|
||
|
|
#include <asm/tlbflush.h>
|
||
|
|
#include <asm/traps.h>
|
||
|
|
|
||
|
|
void __init kasan_early_init(void)
|
||
|
|
{
|
||
|
|
unsigned long vaddr = KASAN_SHADOW_START;
|
||
|
|
pgd_t *pgd = pgd_offset_k(vaddr);
|
||
|
|
pmd_t *pmd = pmd_offset(pgd, vaddr);
|
||
|
|
int i;
|
||
|
|
|
||
|
|
for (i = 0; i < PTRS_PER_PTE; ++i)
|
||
|
|
set_pte(kasan_early_shadow_pte + i,
|
||
|
|
mk_pte(virt_to_page(kasan_early_shadow_page),
|
||
|
|
PAGE_KERNEL));
|
||
|
|
|
||
|
|
for (vaddr = 0; vaddr < KASAN_SHADOW_SIZE; vaddr += PMD_SIZE, ++pmd) {
|
||
|
|
BUG_ON(!pmd_none(*pmd));
|
||
|
|
set_pmd(pmd, __pmd((unsigned long)kasan_early_shadow_pte));
|
||
|
|
}
|
||
|
|
early_trap_init();
|
||
|
|
}
|
||
|
|
|
||
|
|
static void __init populate(void *start, void *end)
|
||
|
|
{
|
||
|
|
unsigned long n_pages = (end - start) / PAGE_SIZE;
|
||
|
|
unsigned long n_pmds = n_pages / PTRS_PER_PTE;
|
||
|
|
unsigned long i, j;
|
||
|
|
unsigned long vaddr = (unsigned long)start;
|
||
|
|
pgd_t *pgd = pgd_offset_k(vaddr);
|
||
|
|
pmd_t *pmd = pmd_offset(pgd, vaddr);
|
||
|
|
pte_t *pte = memblock_virt_alloc(n_pages * sizeof(pte_t), PAGE_SIZE);
|
||
|
|
|
||
|
|
pr_debug("%s: %p - %p\n", __func__, start, end);
|
||
|
|
|
||
|
|
for (i = j = 0; i < n_pmds; ++i) {
|
||
|
|
int k;
|
||
|
|
|
||
|
|
for (k = 0; k < PTRS_PER_PTE; ++k, ++j) {
|
||
|
|
phys_addr_t phys =
|
||
|
|
memblock_alloc_base(PAGE_SIZE, PAGE_SIZE,
|
||
|
|
MEMBLOCK_ALLOC_ANYWHERE);
|
||
|
|
|
||
|
|
set_pte(pte + j, pfn_pte(PHYS_PFN(phys), PAGE_KERNEL));
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
for (i = 0; i < n_pmds ; ++i, pte += PTRS_PER_PTE)
|
||
|
|
set_pmd(pmd + i, __pmd((unsigned long)pte));
|
||
|
|
|
||
|
|
local_flush_tlb_all();
|
||
|
|
memset(start, 0, end - start);
|
||
|
|
}
|
||
|
|
|
||
|
|
void __init kasan_init(void)
|
||
|
|
{
|
||
|
|
int i;
|
||
|
|
|
||
|
|
BUILD_BUG_ON(KASAN_SHADOW_OFFSET != KASAN_SHADOW_START -
|
||
|
|
(KASAN_START_VADDR >> KASAN_SHADOW_SCALE_SHIFT));
|
||
|
|
BUILD_BUG_ON(VMALLOC_START < KASAN_START_VADDR);
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Replace shadow map pages that cover addresses from VMALLOC area
|
||
|
|
* start to the end of KSEG with clean writable pages.
|
||
|
|
*/
|
||
|
|
populate(kasan_mem_to_shadow((void *)VMALLOC_START),
|
||
|
|
kasan_mem_to_shadow((void *)XCHAL_KSEG_BYPASS_VADDR));
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Write protect kasan_early_shadow_page and zero-initialize it again.
|
||
|
|
*/
|
||
|
|
for (i = 0; i < PTRS_PER_PTE; ++i)
|
||
|
|
set_pte(kasan_early_shadow_pte + i,
|
||
|
|
mk_pte(virt_to_page(kasan_early_shadow_page),
|
||
|
|
PAGE_KERNEL_RO));
|
||
|
|
|
||
|
|
local_flush_tlb_all();
|
||
|
|
memset(kasan_early_shadow_page, 0, PAGE_SIZE);
|
||
|
|
|
||
|
|
/* At this point kasan is fully initialized. Enable error messages. */
|
||
|
|
current->kasan_depth = 0;
|
||
|
|
pr_info("KernelAddressSanitizer initialized\n");
|
||
|
|
}
|