[deliverable/linux.git] / mm / kasan / kasan.c

/*
 * This file contains shadow memory manipulation code.
 *
 * Copyright (c) 2014 Samsung Electronics Co., Ltd.
 * Author: Andrey Ryabinin <ryabinin.a.a@gmail.com>
 *
 * Some code borrowed from https://github.com/xairy/kasan-prototype by
 *        Andrey Konovalov <adech.fo@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) KBUILD_MODNAME ": " fmt
#define DISABLE_BRANCH_PROFILING

#include <linux/export.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/kmemleak.h>
#include <linux/memblock.h>
#include <linux/memory.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/printk.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/stacktrace.h>
#include <linux/string.h>
#include <linux/types.h>
#include <linux/vmalloc.h>
#include <linux/kasan.h>

#include "kasan.h"
#include "../slab.h"

/*
 * Poisons the shadow memory for 'size' bytes starting from 'addr'.
 * Memory addresses should be aligned to KASAN_SHADOW_SCALE_SIZE.
 */
static void kasan_poison_shadow(const void *address, size_t size, u8 value)
{
	void *shadow_start, *shadow_end;

	shadow_start = kasan_mem_to_shadow(address);
	shadow_end = kasan_mem_to_shadow(address + size);

	memset(shadow_start, value, shadow_end - shadow_start);
}

void kasan_unpoison_shadow(const void *address, size_t size)
{
	kasan_poison_shadow(address, size, 0);

	if (size & KASAN_SHADOW_MASK) {
		u8 *shadow = (u8 *)kasan_mem_to_shadow(address + size);
		*shadow = size & KASAN_SHADOW_MASK;
	}
}


/*
 * All functions below always inlined so compiler could
 * perform better optimizations in each of __asan_loadX/__assn_storeX
 * depending on memory access size X.
 */

static __always_inline bool memory_is_poisoned_1(unsigned long addr)
{
	s8 shadow_value = *(s8 *)kasan_mem_to_shadow((void *)addr);

	if (unlikely(shadow_value)) {
		s8 last_accessible_byte = addr & KASAN_SHADOW_MASK;
		return unlikely(last_accessible_byte >= shadow_value);
	}

	return false;
}

static __always_inline bool memory_is_poisoned_2(unsigned long addr)
{
	u16 *shadow_addr = (u16 *)kasan_mem_to_shadow((void *)addr);

	if (unlikely(*shadow_addr)) {
		if (memory_is_poisoned_1(addr + 1))
			return true;

		/*
		 * If single shadow byte covers 2-byte access, we don't
		 * need to do anything more. Otherwise, test the first
		 * shadow byte.
		 */
		if (likely(((addr + 1) & KASAN_SHADOW_MASK) != 0))
			return false;

		return unlikely(*(u8 *)shadow_addr);
	}

	return false;
}

static __always_inline bool memory_is_poisoned_4(unsigned long addr)
{
	u16 *shadow_addr = (u16 *)kasan_mem_to_shadow((void *)addr);

	if (unlikely(*shadow_addr)) {
		if (memory_is_poisoned_1(addr + 3))
			return true;

		/*
		 * If single shadow byte covers 4-byte access, we don't
		 * need to do anything more. Otherwise, test the first
		 * shadow byte.
		 */
		if (likely(((addr + 3) & KASAN_SHADOW_MASK) >= 3))
			return false;

		return unlikely(*(u8 *)shadow_addr);
	}

	return false;
}

static __always_inline bool memory_is_poisoned_8(unsigned long addr)
{
	u16 *shadow_addr = (u16 *)kasan_mem_to_shadow((void *)addr);

	if (unlikely(*shadow_addr)) {
		if (memory_is_poisoned_1(addr + 7))
			return true;

		/*
		 * If single shadow byte covers 8-byte access, we don't
		 * need to do anything more. Otherwise, test the first
		 * shadow byte.
		 */
		if (likely(IS_ALIGNED(addr, KASAN_SHADOW_SCALE_SIZE)))
			return false;

		return unlikely(*(u8 *)shadow_addr);
	}

	return false;
}

static __always_inline bool memory_is_poisoned_16(unsigned long addr)
{
	u32 *shadow_addr = (u32 *)kasan_mem_to_shadow((void *)addr);

	if (unlikely(*shadow_addr)) {
		u16 shadow_first_bytes = *(u16 *)shadow_addr;

		if (unlikely(shadow_first_bytes))
			return true;

		/*
		 * If two shadow bytes covers 16-byte access, we don't
		 * need to do anything more. Otherwise, test the last
		 * shadow byte.
		 */
		if (likely(IS_ALIGNED(addr, KASAN_SHADOW_SCALE_SIZE)))
			return false;

		return memory_is_poisoned_1(addr + 15);
	}

	return false;
}

static __always_inline unsigned long bytes_is_zero(const u8 *start,
					size_t size)
{
	while (size) {
		if (unlikely(*start))
			return (unsigned long)start;
		start++;
		size--;
	}

	return 0;
}

static __always_inline unsigned long memory_is_zero(const void *start,
						const void *end)
{
	unsigned int words;
	unsigned long ret;
	unsigned int prefix = (unsigned long)start % 8;

	if (end - start <= 16)
		return bytes_is_zero(start, end - start);

	if (prefix) {
		prefix = 8 - prefix;
		ret = bytes_is_zero(start, prefix);
		if (unlikely(ret))
			return ret;
		start += prefix;
	}

	words = (end - start) / 8;
	while (words) {
		if (unlikely(*(u64 *)start))
			return bytes_is_zero(start, 8);
		start += 8;
		words--;
	}

	return bytes_is_zero(start, (end - start) % 8);
}

static __always_inline bool memory_is_poisoned_n(unsigned long addr,
						size_t size)
{
	unsigned long ret;

	ret = memory_is_zero(kasan_mem_to_shadow((void *)addr),
			kasan_mem_to_shadow((void *)addr + size - 1) + 1);

	if (unlikely(ret)) {
		unsigned long last_byte = addr + size - 1;
		s8 *last_shadow = (s8 *)kasan_mem_to_shadow((void *)last_byte);

		if (unlikely(ret != (unsigned long)last_shadow ||
			((long)(last_byte & KASAN_SHADOW_MASK) >= *last_shadow)))
			return true;
	}
	return false;
}

static __always_inline bool memory_is_poisoned(unsigned long addr, size_t size)
{
	if (__builtin_constant_p(size)) {
		switch (size) {
		case 1:
			return memory_is_poisoned_1(addr);
		case 2:
			return memory_is_poisoned_2(addr);
		case 4:
			return memory_is_poisoned_4(addr);
		case 8:
			return memory_is_poisoned_8(addr);
		case 16:
			return memory_is_poisoned_16(addr);
		default:
			BUILD_BUG();
		}
	}

	return memory_is_poisoned_n(addr, size);
}


static __always_inline void check_memory_region(unsigned long addr,
						size_t size, bool write)
{
	if (unlikely(size == 0))
		return;

	if (unlikely((void *)addr <
		kasan_shadow_to_mem((void *)KASAN_SHADOW_START))) {
		kasan_report(addr, size, write, _RET_IP_);
		return;
	}

	if (likely(!memory_is_poisoned(addr, size)))
		return;

	kasan_report(addr, size, write, _RET_IP_);
}

void __asan_loadN(unsigned long addr, size_t size);
void __asan_storeN(unsigned long addr, size_t size);

#undef memset
void *memset(void *addr, int c, size_t len)
{
	__asan_storeN((unsigned long)addr, len);

	return __memset(addr, c, len);
}

#undef memmove
void *memmove(void *dest, const void *src, size_t len)
{
	__asan_loadN((unsigned long)src, len);
	__asan_storeN((unsigned long)dest, len);

	return __memmove(dest, src, len);
}

#undef memcpy
void *memcpy(void *dest, const void *src, size_t len)
{
	__asan_loadN((unsigned long)src, len);
	__asan_storeN((unsigned long)dest, len);

	return __memcpy(dest, src, len);
}

void kasan_alloc_pages(struct page *page, unsigned int order)
{
	if (likely(!PageHighMem(page)))
		kasan_unpoison_shadow(page_address(page), PAGE_SIZE << order);
}

void kasan_free_pages(struct page *page, unsigned int order)
{
	if (likely(!PageHighMem(page)))
		kasan_poison_shadow(page_address(page),
				PAGE_SIZE << order,
				KASAN_FREE_PAGE);
}

void kasan_poison_slab(struct page *page)
{
	kasan_poison_shadow(page_address(page),
			PAGE_SIZE << compound_order(page),
			KASAN_KMALLOC_REDZONE);
}

void kasan_unpoison_object_data(struct kmem_cache *cache, void *object)
{
	kasan_unpoison_shadow(object, cache->object_size);
}

void kasan_poison_object_data(struct kmem_cache *cache, void *object)
{
	kasan_poison_shadow(object,
			round_up(cache->object_size, KASAN_SHADOW_SCALE_SIZE),
			KASAN_KMALLOC_REDZONE);
}

void kasan_slab_alloc(struct kmem_cache *cache, void *object)
{
	kasan_kmalloc(cache, object, cache->object_size);
}

void kasan_slab_free(struct kmem_cache *cache, void *object)
{
	unsigned long size = cache->object_size;
	unsigned long rounded_up_size = round_up(size, KASAN_SHADOW_SCALE_SIZE);

	/* RCU slabs could be legally used after free within the RCU period */
	if (unlikely(cache->flags & SLAB_DESTROY_BY_RCU))
		return;

	kasan_poison_shadow(object, rounded_up_size, KASAN_KMALLOC_FREE);
}

void kasan_kmalloc(struct kmem_cache *cache, const void *object, size_t size)
{
	unsigned long redzone_start;
	unsigned long redzone_end;

	if (unlikely(object == NULL))
		return;

	redzone_start = round_up((unsigned long)(object + size),
				KASAN_SHADOW_SCALE_SIZE);
	redzone_end = round_up((unsigned long)object + cache->object_size,
				KASAN_SHADOW_SCALE_SIZE);

	kasan_unpoison_shadow(object, size);
	kasan_poison_shadow((void *)redzone_start, redzone_end - redzone_start,
		KASAN_KMALLOC_REDZONE);
}
EXPORT_SYMBOL(kasan_kmalloc);

void kasan_kmalloc_large(const void *ptr, size_t size)
{
	struct page *page;
	unsigned long redzone_start;
	unsigned long redzone_end;

	if (unlikely(ptr == NULL))
		return;

	page = virt_to_page(ptr);
	redzone_start = round_up((unsigned long)(ptr + size),
				KASAN_SHADOW_SCALE_SIZE);
	redzone_end = (unsigned long)ptr + (PAGE_SIZE << compound_order(page));

	kasan_unpoison_shadow(ptr, size);
	kasan_poison_shadow((void *)redzone_start, redzone_end - redzone_start,
		KASAN_PAGE_REDZONE);
}

void kasan_krealloc(const void *object, size_t size)
{
	struct page *page;

	if (unlikely(object == ZERO_SIZE_PTR))
		return;

	page = virt_to_head_page(object);

	if (unlikely(!PageSlab(page)))
		kasan_kmalloc_large(object, size);
	else
		kasan_kmalloc(page->slab_cache, object, size);
}

void kasan_kfree(void *ptr)
{
	struct page *page;

	page = virt_to_head_page(ptr);

	if (unlikely(!PageSlab(page)))
		kasan_poison_shadow(ptr, PAGE_SIZE << compound_order(page),
				KASAN_FREE_PAGE);
	else
		kasan_slab_free(page->slab_cache, ptr);
}

void kasan_kfree_large(const void *ptr)
{
	struct page *page = virt_to_page(ptr);

	kasan_poison_shadow(ptr, PAGE_SIZE << compound_order(page),
			KASAN_FREE_PAGE);
}

int kasan_module_alloc(void *addr, size_t size)
{
	void *ret;
	size_t shadow_size;
	unsigned long shadow_start;

	shadow_start = (unsigned long)kasan_mem_to_shadow(addr);
	shadow_size = round_up(size >> KASAN_SHADOW_SCALE_SHIFT,
			PAGE_SIZE);

	if (WARN_ON(!PAGE_ALIGNED(shadow_start)))
		return -EINVAL;

	ret = __vmalloc_node_range(shadow_size, 1, shadow_start,
			shadow_start + shadow_size,
			GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO,
			PAGE_KERNEL, VM_NO_GUARD, NUMA_NO_NODE,
			__builtin_return_address(0));

	if (ret) {
		find_vm_area(addr)->flags |= VM_KASAN;
		kmemleak_ignore(ret);
		return 0;
	}

	return -ENOMEM;
}

void kasan_free_shadow(const struct vm_struct *vm)
{
	if (vm->flags & VM_KASAN)
		vfree(kasan_mem_to_shadow(vm->addr));
}

static void register_global(struct kasan_global *global)
{
	size_t aligned_size = round_up(global->size, KASAN_SHADOW_SCALE_SIZE);

	kasan_unpoison_shadow(global->beg, global->size);

	kasan_poison_shadow(global->beg + aligned_size,
		global->size_with_redzone - aligned_size,
		KASAN_GLOBAL_REDZONE);
}

void __asan_register_globals(struct kasan_global *globals, size_t size)
{
	int i;

	for (i = 0; i < size; i++)
		register_global(&globals[i]);
}
EXPORT_SYMBOL(__asan_register_globals);

void __asan_unregister_globals(struct kasan_global *globals, size_t size)
{
}
EXPORT_SYMBOL(__asan_unregister_globals);

#define DEFINE_ASAN_LOAD_STORE(size)				\
	void __asan_load##size(unsigned long addr)		\
	{							\
		check_memory_region(addr, size, false);		\
	}							\
	EXPORT_SYMBOL(__asan_load##size);			\
	__alias(__asan_load##size)				\
	void __asan_load##size##_noabort(unsigned long);	\
	EXPORT_SYMBOL(__asan_load##size##_noabort);		\
	void __asan_store##size(unsigned long addr)		\
	{							\
		check_memory_region(addr, size, true);		\
	}							\
	EXPORT_SYMBOL(__asan_store##size);			\
	__alias(__asan_store##size)				\
	void __asan_store##size##_noabort(unsigned long);	\
	EXPORT_SYMBOL(__asan_store##size##_noabort)

DEFINE_ASAN_LOAD_STORE(1);
DEFINE_ASAN_LOAD_STORE(2);
DEFINE_ASAN_LOAD_STORE(4);
DEFINE_ASAN_LOAD_STORE(8);
DEFINE_ASAN_LOAD_STORE(16);

void __asan_loadN(unsigned long addr, size_t size)
{
	check_memory_region(addr, size, false);
}
EXPORT_SYMBOL(__asan_loadN);

__alias(__asan_loadN)
void __asan_loadN_noabort(unsigned long, size_t);
EXPORT_SYMBOL(__asan_loadN_noabort);

void __asan_storeN(unsigned long addr, size_t size)
{
	check_memory_region(addr, size, true);
}
EXPORT_SYMBOL(__asan_storeN);

__alias(__asan_storeN)
void __asan_storeN_noabort(unsigned long, size_t);
EXPORT_SYMBOL(__asan_storeN_noabort);

/* to shut up compiler complaints */
void __asan_handle_no_return(void) {}
EXPORT_SYMBOL(__asan_handle_no_return);

#ifdef CONFIG_MEMORY_HOTPLUG
static int kasan_mem_notifier(struct notifier_block *nb,
			unsigned long action, void *data)
{
	return (action == MEM_GOING_ONLINE) ? NOTIFY_BAD : NOTIFY_OK;
}

static int __init kasan_memhotplug_init(void)
{
	pr_err("WARNING: KASAN doesn't support memory hot-add\n");
	pr_err("Memory hot-add will be disabled\n");

	hotplug_memory_notifier(kasan_mem_notifier, 0);

	return 0;
}

module_init(kasan_memhotplug_init);
#endif
Commit	Line	Data
0b24becc AR	1	/*
	2	* This file contains shadow memory manipulation code.
	3	*
	4	* Copyright (c) 2014 Samsung Electronics Co., Ltd.
2baf9e89	5	* Author: Andrey Ryabinin <ryabinin.a.a@gmail.com>
0b24becc	6	*
5d0926ef	7	* Some code borrowed from https://github.com/xairy/kasan-prototype by
0b24becc AR	8	* Andrey Konovalov <adech.fo@gmail.com>
	9	*
	10	* This program is free software; you can redistribute it and/or modify
	11	* it under the terms of the GNU General Public License version 2 as
	12	* published by the Free Software Foundation.
	13	*
	14	*/
	15
	16	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
	17	#define DISABLE_BRANCH_PROFILING
	18
	19	#include <linux/export.h>
	20	#include <linux/init.h>
	21	#include <linux/kernel.h>
45937254	22	#include <linux/kmemleak.h>
0b24becc	23	#include <linux/memblock.h>
786a8959	24	#include <linux/memory.h>
0b24becc	25	#include <linux/mm.h>
bebf56a1	26	#include <linux/module.h>
0b24becc AR	27	#include <linux/printk.h>
	28	#include <linux/sched.h>
	29	#include <linux/slab.h>
	30	#include <linux/stacktrace.h>
	31	#include <linux/string.h>
	32	#include <linux/types.h>
a5af5aa8	33	#include <linux/vmalloc.h>
0b24becc AR	34	#include <linux/kasan.h>
	35
	36	#include "kasan.h"
0316bec2	37	#include "../slab.h"
0b24becc AR	38
	39	/*
	40	* Poisons the shadow memory for 'size' bytes starting from 'addr'.
	41	* Memory addresses should be aligned to KASAN_SHADOW_SCALE_SIZE.
	42	*/
	43	static void kasan_poison_shadow(const void *address, size_t size, u8 value)
	44	{
	45	void shadow_start, shadow_end;
	46
	47	shadow_start = kasan_mem_to_shadow(address);
	48	shadow_end = kasan_mem_to_shadow(address + size);
	49
	50	memset(shadow_start, value, shadow_end - shadow_start);
	51	}
	52
	53	void kasan_unpoison_shadow(const void *address, size_t size)
	54	{
	55	kasan_poison_shadow(address, size, 0);
	56
	57	if (size & KASAN_SHADOW_MASK) {
	58	u8 shadow = (u8 )kasan_mem_to_shadow(address + size);
	59	*shadow = size & KASAN_SHADOW_MASK;
	60	}
	61	}
	62
	63
	64	/*
	65	* All functions below always inlined so compiler could
	66	* perform better optimizations in each of __asan_loadX/__assn_storeX
	67	* depending on memory access size X.
	68	*/
	69
	70	static __always_inline bool memory_is_poisoned_1(unsigned long addr)
	71	{
	72	s8 shadow_value = (s8 )kasan_mem_to_shadow((void *)addr);
	73
	74	if (unlikely(shadow_value)) {
	75	s8 last_accessible_byte = addr & KASAN_SHADOW_MASK;
	76	return unlikely(last_accessible_byte >= shadow_value);
	77	}
	78
	79	return false;
	80	}
	81
	82	static __always_inline bool memory_is_poisoned_2(unsigned long addr)
	83	{
	84	u16 shadow_addr = (u16 )kasan_mem_to_shadow((void *)addr);
	85
	86	if (unlikely(*shadow_addr)) {
	87	if (memory_is_poisoned_1(addr + 1))
	88	return true;
	89
10f70262 XQ	90	/*
	91	* If single shadow byte covers 2-byte access, we don't
	92	* need to do anything more. Otherwise, test the first
	93	* shadow byte.
	94	*/
0b24becc AR	95	if (likely(((addr + 1) & KASAN_SHADOW_MASK) != 0))
	96	return false;
	97
	98	return unlikely((u8 )shadow_addr);
	99	}
	100
	101	return false;
	102	}
	103
	104	static __always_inline bool memory_is_poisoned_4(unsigned long addr)
	105	{
	106	u16 shadow_addr = (u16 )kasan_mem_to_shadow((void *)addr);
	107
	108	if (unlikely(*shadow_addr)) {
	109	if (memory_is_poisoned_1(addr + 3))
	110	return true;
	111
10f70262 XQ	112	/*
	113	* If single shadow byte covers 4-byte access, we don't
	114	* need to do anything more. Otherwise, test the first
	115	* shadow byte.
	116	*/
0b24becc AR	117	if (likely(((addr + 3) & KASAN_SHADOW_MASK) >= 3))
	118	return false;
	119
	120	return unlikely((u8 )shadow_addr);
	121	}
	122
	123	return false;
	124	}
	125
	126	static __always_inline bool memory_is_poisoned_8(unsigned long addr)
	127	{
	128	u16 shadow_addr = (u16 )kasan_mem_to_shadow((void *)addr);
	129
	130	if (unlikely(*shadow_addr)) {
	131	if (memory_is_poisoned_1(addr + 7))
	132	return true;
	133
10f70262 XQ	134	/*
	135	* If single shadow byte covers 8-byte access, we don't
	136	* need to do anything more. Otherwise, test the first
	137	* shadow byte.
	138	*/
	139	if (likely(IS_ALIGNED(addr, KASAN_SHADOW_SCALE_SIZE)))
0b24becc AR	140	return false;
	141
	142	return unlikely((u8 )shadow_addr);
	143	}
	144
	145	return false;
	146	}
	147
	148	static __always_inline bool memory_is_poisoned_16(unsigned long addr)
	149	{
	150	u32 shadow_addr = (u32 )kasan_mem_to_shadow((void *)addr);
	151
	152	if (unlikely(*shadow_addr)) {
	153	u16 shadow_first_bytes = (u16 )shadow_addr;
0b24becc AR	154
	155	if (unlikely(shadow_first_bytes))
	156	return true;
	157
10f70262 XQ	158	/*
	159	* If two shadow bytes covers 16-byte access, we don't
	160	* need to do anything more. Otherwise, test the last
	161	* shadow byte.
	162	*/
	163	if (likely(IS_ALIGNED(addr, KASAN_SHADOW_SCALE_SIZE)))
0b24becc AR	164	return false;
	165
	166	return memory_is_poisoned_1(addr + 15);
	167	}
	168
	169	return false;
	170	}
	171
	172	static __always_inline unsigned long bytes_is_zero(const u8 *start,
	173	size_t size)
	174	{
	175	while (size) {
	176	if (unlikely(*start))
	177	return (unsigned long)start;
	178	start++;
	179	size--;
	180	}
	181
	182	return 0;
	183	}
	184
	185	static __always_inline unsigned long memory_is_zero(const void *start,
	186	const void *end)
	187	{
	188	unsigned int words;
	189	unsigned long ret;
	190	unsigned int prefix = (unsigned long)start % 8;
	191
	192	if (end - start <= 16)
	193	return bytes_is_zero(start, end - start);
	194
	195	if (prefix) {
	196	prefix = 8 - prefix;
	197	ret = bytes_is_zero(start, prefix);
	198	if (unlikely(ret))
	199	return ret;
	200	start += prefix;
	201	}
	202
	203	words = (end - start) / 8;
	204	while (words) {
	205	if (unlikely((u64 )start))
	206	return bytes_is_zero(start, 8);
	207	start += 8;
	208	words--;
	209	}
	210
	211	return bytes_is_zero(start, (end - start) % 8);
	212	}
	213
	214	static __always_inline bool memory_is_poisoned_n(unsigned long addr,
	215	size_t size)
	216	{
	217	unsigned long ret;
	218
	219	ret = memory_is_zero(kasan_mem_to_shadow((void *)addr),
	220	kasan_mem_to_shadow((void *)addr + size - 1) + 1);
	221
	222	if (unlikely(ret)) {
	223	unsigned long last_byte = addr + size - 1;
	224	s8 last_shadow = (s8 )kasan_mem_to_shadow((void *)last_byte);
	225
	226	if (unlikely(ret != (unsigned long)last_shadow \|\|
e0d57714	227	((long)(last_byte & KASAN_SHADOW_MASK) >= *last_shadow)))
0b24becc AR	228	return true;
	229	}
	230	return false;
	231	}
	232
	233	static __always_inline bool memory_is_poisoned(unsigned long addr, size_t size)
	234	{
	235	if (__builtin_constant_p(size)) {
	236	switch (size) {
	237	case 1:
	238	return memory_is_poisoned_1(addr);
	239	case 2:
	240	return memory_is_poisoned_2(addr);
	241	case 4:
	242	return memory_is_poisoned_4(addr);
	243	case 8:
	244	return memory_is_poisoned_8(addr);
	245	case 16:
	246	return memory_is_poisoned_16(addr);
	247	default:
	248	BUILD_BUG();
	249	}
	250	}
	251
	252	return memory_is_poisoned_n(addr, size);
	253	}
	254
	255
	256	static __always_inline void check_memory_region(unsigned long addr,
	257	size_t size, bool write)
	258	{
0b24becc AR	259	if (unlikely(size == 0))
	260	return;
	261
	262	if (unlikely((void *)addr <
	263	kasan_shadow_to_mem((void *)KASAN_SHADOW_START))) {
e9121076	264	kasan_report(addr, size, write, _RET_IP_);
0b24becc AR	265	return;
	266	}
	267
	268	if (likely(!memory_is_poisoned(addr, size)))
	269	return;
	270
	271	kasan_report(addr, size, write, _RET_IP_);
	272	}
	273
393f203f AR	274	void __asan_loadN(unsigned long addr, size_t size);
	275	void __asan_storeN(unsigned long addr, size_t size);
	276
	277	#undef memset
	278	void memset(void addr, int c, size_t len)
	279	{
	280	__asan_storeN((unsigned long)addr, len);
	281
	282	return __memset(addr, c, len);
	283	}
	284
	285	#undef memmove
	286	void memmove(void dest, const void *src, size_t len)
	287	{
	288	__asan_loadN((unsigned long)src, len);
	289	__asan_storeN((unsigned long)dest, len);
	290
	291	return __memmove(dest, src, len);
	292	}
	293
	294	#undef memcpy
	295	void memcpy(void dest, const void *src, size_t len)
	296	{
	297	__asan_loadN((unsigned long)src, len);
	298	__asan_storeN((unsigned long)dest, len);
	299
	300	return __memcpy(dest, src, len);
	301	}
	302
b8c73fc2 AR	303	void kasan_alloc_pages(struct page *page, unsigned int order)
	304	{
	305	if (likely(!PageHighMem(page)))
	306	kasan_unpoison_shadow(page_address(page), PAGE_SIZE << order);
	307	}
	308
	309	void kasan_free_pages(struct page *page, unsigned int order)
	310	{
	311	if (likely(!PageHighMem(page)))
	312	kasan_poison_shadow(page_address(page),
	313	PAGE_SIZE << order,
	314	KASAN_FREE_PAGE);
	315	}
	316
0316bec2 AR	317	void kasan_poison_slab(struct page *page)
	318	{
	319	kasan_poison_shadow(page_address(page),
	320	PAGE_SIZE << compound_order(page),
	321	KASAN_KMALLOC_REDZONE);
	322	}
	323
	324	void kasan_unpoison_object_data(struct kmem_cache cache, void object)
	325	{
	326	kasan_unpoison_shadow(object, cache->object_size);
	327	}
	328
	329	void kasan_poison_object_data(struct kmem_cache cache, void object)
	330	{
	331	kasan_poison_shadow(object,
	332	round_up(cache->object_size, KASAN_SHADOW_SCALE_SIZE),
	333	KASAN_KMALLOC_REDZONE);
	334	}
	335
	336	void kasan_slab_alloc(struct kmem_cache cache, void object)
	337	{
	338	kasan_kmalloc(cache, object, cache->object_size);
	339	}
	340
	341	void kasan_slab_free(struct kmem_cache cache, void object)
	342	{
	343	unsigned long size = cache->object_size;
	344	unsigned long rounded_up_size = round_up(size, KASAN_SHADOW_SCALE_SIZE);
	345
	346	/* RCU slabs could be legally used after free within the RCU period */
	347	if (unlikely(cache->flags & SLAB_DESTROY_BY_RCU))
	348	return;
	349
	350	kasan_poison_shadow(object, rounded_up_size, KASAN_KMALLOC_FREE);
	351	}
	352
	353	void kasan_kmalloc(struct kmem_cache cache, const void object, size_t size)
	354	{
	355	unsigned long redzone_start;
	356	unsigned long redzone_end;
	357
	358	if (unlikely(object == NULL))
	359	return;
	360
	361	redzone_start = round_up((unsigned long)(object + size),
	362	KASAN_SHADOW_SCALE_SIZE);
	363	redzone_end = round_up((unsigned long)object + cache->object_size,
	364	KASAN_SHADOW_SCALE_SIZE);
	365
	366	kasan_unpoison_shadow(object, size);
	367	kasan_poison_shadow((void *)redzone_start, redzone_end - redzone_start,
	368	KASAN_KMALLOC_REDZONE);
	369	}
	370	EXPORT_SYMBOL(kasan_kmalloc);
	371
	372	void kasan_kmalloc_large(const void *ptr, size_t size)
	373	{
	374	struct page *page;
	375	unsigned long redzone_start;
	376	unsigned long redzone_end;
	377
	378	if (unlikely(ptr == NULL))
	379	return;
	380
381	page = virt_to_page(ptr);
382	redzone_start = round_up((unsigned long)(ptr + size),
383	KASAN_SHADOW_SCALE_SIZE);
384	redzone_end = (unsigned long)ptr + (PAGE_SIZE << compound_order(page));
385
386	kasan_unpoison_shadow(ptr, size);
387	kasan_poison_shadow((void *)redzone_start, redzone_end - redzone_start,
388	KASAN_PAGE_REDZONE);
389	}
390
391	void kasan_krealloc(const void *object, size_t size)
392	{
393	struct page *page;
394
395	if (unlikely(object == ZERO_SIZE_PTR))
396	return;
397
398	page = virt_to_head_page(object);
399
400	if (unlikely(!PageSlab(page)))
401	kasan_kmalloc_large(object, size);
402	else
403	kasan_kmalloc(page->slab_cache, object, size);
404	}
405
92393615 AR	406	void kasan_kfree(void *ptr)
	407	{
	408	struct page *page;
	409
	410	page = virt_to_head_page(ptr);
	411
	412	if (unlikely(!PageSlab(page)))
	413	kasan_poison_shadow(ptr, PAGE_SIZE << compound_order(page),
	414	KASAN_FREE_PAGE);
	415	else
	416	kasan_slab_free(page->slab_cache, ptr);
	417	}
	418
0316bec2 AR	419	void kasan_kfree_large(const void *ptr)
	420	{
	421	struct page *page = virt_to_page(ptr);
	422
	423	kasan_poison_shadow(ptr, PAGE_SIZE << compound_order(page),
	424	KASAN_FREE_PAGE);
	425	}
	426
bebf56a1 AR	427	int kasan_module_alloc(void *addr, size_t size)
	428	{
	429	void *ret;
	430	size_t shadow_size;
	431	unsigned long shadow_start;
	432
	433	shadow_start = (unsigned long)kasan_mem_to_shadow(addr);
	434	shadow_size = round_up(size >> KASAN_SHADOW_SCALE_SHIFT,
	435	PAGE_SIZE);
	436
	437	if (WARN_ON(!PAGE_ALIGNED(shadow_start)))
	438	return -EINVAL;
	439
	440	ret = __vmalloc_node_range(shadow_size, 1, shadow_start,
	441	shadow_start + shadow_size,
	442	GFP_KERNEL \| __GFP_HIGHMEM \| __GFP_ZERO,
	443	PAGE_KERNEL, VM_NO_GUARD, NUMA_NO_NODE,
	444	__builtin_return_address(0));
a5af5aa8 AR	445
	446	if (ret) {
	447	find_vm_area(addr)->flags \|= VM_KASAN;
45937254	448	kmemleak_ignore(ret);
a5af5aa8 AR	449	return 0;
	450	}
	451
	452	return -ENOMEM;
bebf56a1 AR	453	}
bebf56a1 AR	454
a5af5aa8	455	void kasan_free_shadow(const struct vm_struct *vm)
bebf56a1	456	{
a5af5aa8 AR	457	if (vm->flags & VM_KASAN)
a5af5aa8 AR	458	vfree(kasan_mem_to_shadow(vm->addr));
bebf56a1 AR	459	}
	460
	461	static void register_global(struct kasan_global *global)
	462	{
	463	size_t aligned_size = round_up(global->size, KASAN_SHADOW_SCALE_SIZE);
	464
	465	kasan_unpoison_shadow(global->beg, global->size);
	466
	467	kasan_poison_shadow(global->beg + aligned_size,
	468	global->size_with_redzone - aligned_size,
	469	KASAN_GLOBAL_REDZONE);
	470	}
	471
	472	void __asan_register_globals(struct kasan_global *globals, size_t size)
	473	{
	474	int i;
	475
	476	for (i = 0; i < size; i++)
	477	register_global(&globals[i]);
	478	}
	479	EXPORT_SYMBOL(__asan_register_globals);
	480
	481	void __asan_unregister_globals(struct kasan_global *globals, size_t size)
	482	{
	483	}
	484	EXPORT_SYMBOL(__asan_unregister_globals);
	485
0b24becc AR	486	#define DEFINE_ASAN_LOAD_STORE(size) \
	487	void __asan_load##size(unsigned long addr) \
	488	{ \
	489	check_memory_region(addr, size, false); \
	490	} \
	491	EXPORT_SYMBOL(__asan_load##size); \
	492	__alias(__asan_load##size) \
	493	void __asan_load##size##_noabort(unsigned long); \
	494	EXPORT_SYMBOL(__asan_load##size##_noabort); \
	495	void __asan_store##size(unsigned long addr) \
	496	{ \
	497	check_memory_region(addr, size, true); \
	498	} \
	499	EXPORT_SYMBOL(__asan_store##size); \
	500	__alias(__asan_store##size) \
	501	void __asan_store##size##_noabort(unsigned long); \
	502	EXPORT_SYMBOL(__asan_store##size##_noabort)
	503
	504	DEFINE_ASAN_LOAD_STORE(1);
	505	DEFINE_ASAN_LOAD_STORE(2);
	506	DEFINE_ASAN_LOAD_STORE(4);
	507	DEFINE_ASAN_LOAD_STORE(8);
	508	DEFINE_ASAN_LOAD_STORE(16);
	509
	510	void __asan_loadN(unsigned long addr, size_t size)
	511	{
	512	check_memory_region(addr, size, false);
	513	}
	514	EXPORT_SYMBOL(__asan_loadN);
	515
	516	__alias(__asan_loadN)
	517	void __asan_loadN_noabort(unsigned long, size_t);
	518	EXPORT_SYMBOL(__asan_loadN_noabort);
	519
	520	void __asan_storeN(unsigned long addr, size_t size)
	521	{
	522	check_memory_region(addr, size, true);
	523	}
	524	EXPORT_SYMBOL(__asan_storeN);
	525
	526	__alias(__asan_storeN)
	527	void __asan_storeN_noabort(unsigned long, size_t);
	528	EXPORT_SYMBOL(__asan_storeN_noabort);
	529
	530	/* to shut up compiler complaints */
	531	void __asan_handle_no_return(void) {}
	532	EXPORT_SYMBOL(__asan_handle_no_return);
786a8959 AR	533
	534	#ifdef CONFIG_MEMORY_HOTPLUG
	535	static int kasan_mem_notifier(struct notifier_block *nb,
	536	unsigned long action, void *data)
	537	{
	538	return (action == MEM_GOING_ONLINE) ? NOTIFY_BAD : NOTIFY_OK;
	539	}
	540
	541	static int __init kasan_memhotplug_init(void)
	542	{
25add7ec	543	pr_err("WARNING: KASAN doesn't support memory hot-add\n");
786a8959 AR	544	pr_err("Memory hot-add will be disabled\n");
	545
	546	hotplug_memory_notifier(kasan_mem_notifier, 0);
	547
	548	return 0;
	549	}
	550
	551	module_init(kasan_memhotplug_init);
	552	#endif