@@ -48,6 +48,7 @@ config ARM64
select HAVE_ARCH_AUDITSYSCALL
select HAVE_ARCH_BITREVERSE
select HAVE_ARCH_JUMP_LABEL
+ select HAVE_ARCH_KASAN if SPARSEMEM_VMEMMAP
select HAVE_ARCH_KGDB
select HAVE_ARCH_SECCOMP_FILTER
select HAVE_ARCH_TRACEHOOK
@@ -55,6 +55,13 @@ else
TEXT_OFFSET := 0x00080000
endif
+# KASAN_SHADOW_OFFSET = VA_START + (1 << (VA_BITS - 3)) - (1 << 61)
+# in 32-bit arithmetic
+KASAN_SHADOW_OFFSET := $(shell printf "0x%08x00000000\n" $$(( \
+ (0xffffffff & (-1 << ($(CONFIG_ARM64_VA_BITS) - 32))) \
+ + (1 << ($(CONFIG_ARM64_VA_BITS) - 32 - 3)) \
+ - (1 << (64 - 32 - 3)) )) )
+
export TEXT_OFFSET GZFLAGS
core-y += arch/arm64/kernel/ arch/arm64/mm/
new file mode 100644
@@ -0,0 +1,36 @@
+#ifndef __ASM_KASAN_H
+#define __ASM_KASAN_H
+
+#ifndef __ASSEMBLY__
+
+#ifdef CONFIG_KASAN
+
+#include <asm/memory.h>
+
+/*
+ * KASAN_SHADOW_START: beginning of the kernel virtual addresses.
+ * KASAN_SHADOW_END: KASAN_SHADOW_START + 1/8 of kernel virtual addresses.
+ */
+#define KASAN_SHADOW_START (VA_START)
+#define KASAN_SHADOW_END (KASAN_SHADOW_START + (1UL << (VA_BITS - 3)))
+
+/*
+ * This value is used to map an address to the corresponding shadow
+ * address by the following formula:
+ * shadow_addr = (address >> 3) + KASAN_SHADOW_OFFSET;
+ *
+ * (1 << 61) shadow addresses - [KASAN_SHADOW_OFFSET,KASAN_SHADOW_END]
+ * cover all 64-bits of virtual addresses. So KASAN_SHADOW_OFFSET
+ * should satisfy the following equation:
+ * KASAN_SHADOW_OFFSET = KASAN_SHADOW_END - (1ULL << 61)
+ */
+#define KASAN_SHADOW_OFFSET (KASAN_SHADOW_END - (1ULL << (64 - 3)))
+
+void kasan_init(void);
+
+#else
+static inline void kasan_init(void) { }
+#endif
+
+#endif
+#endif
@@ -41,7 +41,14 @@
* fixed mappings and modules
*/
#define VMEMMAP_SIZE ALIGN((1UL << (VA_BITS - PAGE_SHIFT)) * sizeof(struct page), PUD_SIZE)
+
+#ifndef CONFIG_KASAN
#define VMALLOC_START (VA_START)
+#else
+#include <asm/kasan.h>
+#define VMALLOC_START (KASAN_SHADOW_END + SZ_64K)
+#endif
+
#define VMALLOC_END (PAGE_OFFSET - PUD_SIZE - VMEMMAP_SIZE - SZ_64K)
#define vmemmap ((struct page *)(VMALLOC_END + SZ_64K))
@@ -36,17 +36,33 @@ extern __kernel_size_t strnlen(const char *, __kernel_size_t);
#define __HAVE_ARCH_MEMCPY
extern void *memcpy(void *, const void *, __kernel_size_t);
+extern void *__memcpy(void *, const void *, __kernel_size_t);
#define __HAVE_ARCH_MEMMOVE
extern void *memmove(void *, const void *, __kernel_size_t);
+extern void *__memmove(void *, const void *, __kernel_size_t);
#define __HAVE_ARCH_MEMCHR
extern void *memchr(const void *, int, __kernel_size_t);
#define __HAVE_ARCH_MEMSET
extern void *memset(void *, int, __kernel_size_t);
+extern void *__memset(void *, int, __kernel_size_t);
#define __HAVE_ARCH_MEMCMP
extern int memcmp(const void *, const void *, size_t);
+
+#if defined(CONFIG_KASAN) && !defined(__SANITIZE_ADDRESS__)
+
+/*
+ * For files that are not instrumented (e.g. mm/slub.c) we
+ * should use not instrumented version of mem* functions.
+ */
+
+#define memcpy(dst, src, len) __memcpy(dst, src, len)
+#define memmove(dst, src, len) __memmove(dst, src, len)
+#define memset(s, c, n) __memset(s, c, n)
+#endif
+
#endif
@@ -7,6 +7,8 @@ AFLAGS_head.o := -DTEXT_OFFSET=$(TEXT_OFFSET)
CFLAGS_efi-stub.o := -DTEXT_OFFSET=$(TEXT_OFFSET)
CFLAGS_armv8_deprecated.o := -I$(src)
+KASAN_SANITIZE_efi-stub.o := n
+
CFLAGS_REMOVE_ftrace.o = -pg
CFLAGS_REMOVE_insn.o = -pg
CFLAGS_REMOVE_return_address.o = -pg
@@ -51,6 +51,9 @@ EXPORT_SYMBOL(strnlen);
EXPORT_SYMBOL(memset);
EXPORT_SYMBOL(memcpy);
EXPORT_SYMBOL(memmove);
+EXPORT_SYMBOL(__memset);
+EXPORT_SYMBOL(__memcpy);
+EXPORT_SYMBOL(__memmove);
EXPORT_SYMBOL(memchr);
EXPORT_SYMBOL(memcmp);
@@ -444,6 +444,9 @@ __mmap_switched:
str_l x21, __fdt_pointer, x5 // Save FDT pointer
str_l x24, memstart_addr, x6 // Save PHYS_OFFSET
mov x29, #0
+#ifdef CONFIG_KASAN
+ bl kasan_early_init
+#endif
b start_kernel
ENDPROC(__mmap_switched)
@@ -80,6 +80,12 @@ __efistub_strcmp = __pi_strcmp;
__efistub_strncmp = __pi_strncmp;
__efistub___flush_dcache_area = __pi___flush_dcache_area;
+#ifdef CONFIG_KASAN
+__efistub___memcpy = __pi_memcpy;
+__efistub___memmove = __pi_memmove;
+__efistub___memset = __pi_memset;
+#endif
+
__efistub__text = _text;
__efistub__end = _end;
__efistub__edata = _edata;
@@ -21,6 +21,7 @@
#include <linux/bitops.h>
#include <linux/elf.h>
#include <linux/gfp.h>
+#include <linux/kasan.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/moduleloader.h>
@@ -34,9 +35,18 @@
void *module_alloc(unsigned long size)
{
- return __vmalloc_node_range(size, 1, MODULES_VADDR, MODULES_END,
- GFP_KERNEL, PAGE_KERNEL_EXEC, 0,
- NUMA_NO_NODE, __builtin_return_address(0));
+ void *p;
+
+ p = __vmalloc_node_range(size, MODULE_ALIGN, MODULES_VADDR, MODULES_END,
+ GFP_KERNEL, PAGE_KERNEL_EXEC, 0,
+ NUMA_NO_NODE, __builtin_return_address(0));
+
+ if (p && (kasan_module_alloc(p, size) < 0)) {
+ vfree(p);
+ return NULL;
+ }
+
+ return p;
}
enum aarch64_reloc_op {
@@ -54,6 +54,7 @@
#include <asm/elf.h>
#include <asm/cpufeature.h>
#include <asm/cpu_ops.h>
+#include <asm/kasan.h>
#include <asm/sections.h>
#include <asm/setup.h>
#include <asm/smp_plat.h>
@@ -434,6 +435,9 @@ void __init setup_arch(char **cmdline_p)
paging_init();
relocate_initrd();
+
+ kasan_init();
+
request_standard_resources();
early_ioremap_reset();
@@ -68,7 +68,10 @@
stp \ptr, \regB, [\regC], \val
.endm
+ .weak memcpy
+ENTRY(__memcpy)
ENTRY(memcpy)
#include "copy_template.S"
ret
ENDPIPROC(memcpy)
+ENDPROC(__memcpy)
@@ -57,12 +57,14 @@ C_h .req x12
D_l .req x13
D_h .req x14
+ .weak memmove
+ENTRY(__memmove)
ENTRY(memmove)
cmp dstin, src
- b.lo memcpy
+ b.lo __memcpy
add tmp1, src, count
cmp dstin, tmp1
- b.hs memcpy /* No overlap. */
+ b.hs __memcpy /* No overlap. */
add dst, dstin, count
add src, src, count
@@ -195,3 +197,4 @@ ENTRY(memmove)
b.ne .Ltail63
ret
ENDPIPROC(memmove)
+ENDPROC(__memmove)
@@ -54,6 +54,8 @@ dst .req x8
tmp3w .req w9
tmp3 .req x9
+ .weak memset
+ENTRY(__memset)
ENTRY(memset)
mov dst, dstin /* Preserve return value. */
and A_lw, val, #255
@@ -214,3 +216,4 @@ ENTRY(memset)
b.ne .Ltail_maybe_long
ret
ENDPIPROC(memset)
+ENDPROC(__memset)
@@ -4,3 +4,6 @@ obj-y := dma-mapping.o extable.o fault.o init.o \
context.o proc.o pageattr.o
obj-$(CONFIG_HUGETLB_PAGE) += hugetlbpage.o
obj-$(CONFIG_ARM64_PTDUMP) += dump.o
+
+obj-$(CONFIG_KASAN) += kasan_init.o
+KASAN_SANITIZE_kasan_init.o := n
new file mode 100644
@@ -0,0 +1,165 @@
+/*
+ * This file contains kasan initialization code for ARM64.
+ *
+ * Copyright (c) 2015 Samsung Electronics Co., Ltd.
+ * Author: Andrey Ryabinin <ryabinin.a.a@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+
+#define pr_fmt(fmt) "kasan: " fmt
+#include <linux/kasan.h>
+#include <linux/kernel.h>
+#include <linux/memblock.h>
+#include <linux/start_kernel.h>
+
+#include <asm/page.h>
+#include <asm/pgalloc.h>
+#include <asm/pgtable.h>
+#include <asm/tlbflush.h>
+
+static pgd_t tmp_pg_dir[PTRS_PER_PGD] __initdata __aligned(PGD_SIZE);
+
+static void __init kasan_early_pte_populate(pmd_t *pmd, unsigned long addr,
+ unsigned long end)
+{
+ pte_t *pte;
+ unsigned long next;
+
+ if (pmd_none(*pmd))
+ pmd_populate_kernel(&init_mm, pmd, kasan_zero_pte);
+
+ pte = pte_offset_kernel(pmd, addr);
+ do {
+ next = addr + PAGE_SIZE;
+ set_pte(pte, pfn_pte(virt_to_pfn(kasan_zero_page),
+ PAGE_KERNEL));
+ } while (pte++, addr = next, addr != end && pte_none(*pte));
+}
+
+static void __init kasan_early_pmd_populate(pud_t *pud,
+ unsigned long addr,
+ unsigned long end)
+{
+ pmd_t *pmd;
+ unsigned long next;
+
+ if (pud_none(*pud))
+ pud_populate(&init_mm, pud, kasan_zero_pmd);
+
+ pmd = pmd_offset(pud, addr);
+ do {
+ next = pmd_addr_end(addr, end);
+ kasan_early_pte_populate(pmd, addr, next);
+ } while (pmd++, addr = next, addr != end && pmd_none(*pmd));
+}
+
+static void __init kasan_early_pud_populate(pgd_t *pgd,
+ unsigned long addr,
+ unsigned long end)
+{
+ pud_t *pud;
+ unsigned long next;
+
+ if (pgd_none(*pgd))
+ pgd_populate(&init_mm, pgd, kasan_zero_pud);
+
+ pud = pud_offset(pgd, addr);
+ do {
+ next = pud_addr_end(addr, end);
+ kasan_early_pmd_populate(pud, addr, next);
+ } while (pud++, addr = next, addr != end && pud_none(*pud));
+}
+
+static void __init kasan_map_early_shadow(void)
+{
+ unsigned long addr = KASAN_SHADOW_START;
+ unsigned long end = KASAN_SHADOW_END;
+ unsigned long next;
+ pgd_t *pgd;
+
+ pgd = pgd_offset_k(addr);
+ do {
+ next = pgd_addr_end(addr, end);
+ kasan_early_pud_populate(pgd, addr, next);
+ } while (pgd++, addr = next, addr != end);
+}
+
+void __init kasan_early_init(void)
+{
+ BUILD_BUG_ON(KASAN_SHADOW_OFFSET != KASAN_SHADOW_END - (1UL << 61));
+ BUILD_BUG_ON(!IS_ALIGNED(KASAN_SHADOW_START, PGDIR_SIZE));
+ BUILD_BUG_ON(!IS_ALIGNED(KASAN_SHADOW_END, PGDIR_SIZE));
+ kasan_map_early_shadow();
+}
+
+static void __init clear_pgds(unsigned long start,
+ unsigned long end)
+{
+ /*
+ * Remove references to kasan page tables from
+ * swapper_pg_dir. pgd_clear() can't be used
+ * here because it's nop on 2,3-level pagetable setups
+ */
+ for (; start < end; start += PGDIR_SIZE)
+ set_pgd(pgd_offset_k(start), __pgd(0));
+}
+
+static void __init cpu_set_ttbr1(unsigned long ttbr1)
+{
+ asm(
+ " msr ttbr1_el1, %0\n"
+ " isb"
+ :
+ : "r" (ttbr1));
+}
+
+void __init kasan_init(void)
+{
+ struct memblock_region *reg;
+
+ /*
+ * We are going to perform proper setup of shadow memory.
+ * At first we should unmap early shadow (clear_pgds() call bellow).
+ * However, instrumented code couldn't execute without shadow memory.
+ * tmp_pg_dir used to keep early shadow mapped until full shadow
+ * setup will be finished.
+ */
+ memcpy(tmp_pg_dir, swapper_pg_dir, sizeof(tmp_pg_dir));
+ cpu_set_ttbr1(__pa(tmp_pg_dir));
+ flush_tlb_all();
+
+ clear_pgds(KASAN_SHADOW_START, KASAN_SHADOW_END);
+
+ kasan_populate_zero_shadow((void *)KASAN_SHADOW_START,
+ kasan_mem_to_shadow((void *)MODULES_VADDR));
+
+ for_each_memblock(memory, reg) {
+ void *start = (void *)__phys_to_virt(reg->base);
+ void *end = (void *)__phys_to_virt(reg->base + reg->size);
+
+ if (start >= end)
+ break;
+
+ /*
+ * 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.
+ */
+ vmemmap_populate((unsigned long)kasan_mem_to_shadow(start),
+ (unsigned long)kasan_mem_to_shadow(end) + 1,
+ pfn_to_nid(virt_to_pfn(start)));
+ }
+
+ memset(kasan_zero_page, 0, PAGE_SIZE);
+ cpu_set_ttbr1(__pa(swapper_pg_dir));
+ flush_tlb_all();
+
+ /* At this point kasan is fully initialized. Enable error messages */
+ init_task.kasan_depth = 0;
+ pr_info("KernelAddressSanitizer initialized\n");
+}
@@ -1,6 +1,14 @@
#
# Makefile for linux kernel
#
+
+#
+# ARM64 maps efi runtime services in userspace addresses
+# which don't have KASAN shadow. So dereference of these addresses
+# in efi_call_virt() will cause crash if this code instrumented.
+#
+KASAN_SANITIZE_runtime-wrappers.o := n
+
obj-$(CONFIG_EFI) += efi.o vars.o reboot.o
obj-$(CONFIG_EFI_VARS) += efivars.o
obj-$(CONFIG_EFI_ESRT) += esrt.o
@@ -5,10 +5,12 @@ else
call_threshold := 0
endif
+KASAN_SHADOW_OFFSET ?= $(CONFIG_KASAN_SHADOW_OFFSET)
+
CFLAGS_KASAN_MINIMAL := -fsanitize=kernel-address
CFLAGS_KASAN := $(call cc-option, -fsanitize=kernel-address \
- -fasan-shadow-offset=$(CONFIG_KASAN_SHADOW_OFFSET) \
+ -fasan-shadow-offset=$(KASAN_SHADOW_OFFSET) \
--param asan-stack=1 --param asan-globals=1 \
--param asan-instrumentation-with-call-threshold=$(call_threshold))