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

/*
 * This file contains shadow memory manipulation code.
 *
 * Copyright (c) 2014 Samsung Electronics Co., Ltd.
 * Author: Andrey Ryabinin <a.ryabinin@samsung.com>
 *
 * Some of code borrowed from https://github.com/xairy/linux 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/memblock.h>
#include <linux/memory.h>
#include <linux/mm.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/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 (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 (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 (likely(((addr + 7) & KASAN_SHADOW_MASK) >= 7))
			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;
		s8 last_byte = (addr + 15) & KASAN_SHADOW_MASK;

		if (unlikely(shadow_first_bytes))
			return true;

		if (likely(!last_byte))
			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 ||
			((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)
{
	struct kasan_access_info info;

	if (unlikely(size == 0))
		return;

	if (unlikely((void *)addr <
		kasan_shadow_to_mem((void *)KASAN_SHADOW_START))) {
		info.access_addr = (void *)addr;
		info.access_size = size;
		info.is_write = write;
		info.ip = _RET_IP_;
		kasan_report_user_access(&info);
		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_large(const void *ptr)
{
	struct page *page = virt_to_page(ptr);

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

#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.
	5	* Author: Andrey Ryabinin <a.ryabinin@samsung.com>
	6	*
	7	* Some of code borrowed from https://github.com/xairy/linux by
	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>
	22	#include <linux/memblock.h>
786a8959	23	#include <linux/memory.h>
0b24becc AR	24	#include <linux/mm.h>
	25	#include <linux/printk.h>
	26	#include <linux/sched.h>
	27	#include <linux/slab.h>
	28	#include <linux/stacktrace.h>
	29	#include <linux/string.h>
	30	#include <linux/types.h>
	31	#include <linux/kasan.h>
	32
	33	#include "kasan.h"
0316bec2	34	#include "../slab.h"
0b24becc AR	35
	36	/*
	37	* Poisons the shadow memory for 'size' bytes starting from 'addr'.
	38	* Memory addresses should be aligned to KASAN_SHADOW_SCALE_SIZE.
	39	*/
	40	static void kasan_poison_shadow(const void *address, size_t size, u8 value)
	41	{
	42	void shadow_start, shadow_end;
	43
	44	shadow_start = kasan_mem_to_shadow(address);
	45	shadow_end = kasan_mem_to_shadow(address + size);
	46
	47	memset(shadow_start, value, shadow_end - shadow_start);
	48	}
	49
	50	void kasan_unpoison_shadow(const void *address, size_t size)
	51	{
	52	kasan_poison_shadow(address, size, 0);
	53
	54	if (size & KASAN_SHADOW_MASK) {
	55	u8 shadow = (u8 )kasan_mem_to_shadow(address + size);
	56	*shadow = size & KASAN_SHADOW_MASK;
	57	}
	58	}
	59
	60
	61	/*
	62	* All functions below always inlined so compiler could
	63	* perform better optimizations in each of __asan_loadX/__assn_storeX
	64	* depending on memory access size X.
	65	*/
	66
	67	static __always_inline bool memory_is_poisoned_1(unsigned long addr)
	68	{
	69	s8 shadow_value = (s8 )kasan_mem_to_shadow((void *)addr);
	70
	71	if (unlikely(shadow_value)) {
	72	s8 last_accessible_byte = addr & KASAN_SHADOW_MASK;
	73	return unlikely(last_accessible_byte >= shadow_value);
	74	}
	75
	76	return false;
	77	}
	78
	79	static __always_inline bool memory_is_poisoned_2(unsigned long addr)
	80	{
	81	u16 shadow_addr = (u16 )kasan_mem_to_shadow((void *)addr);
	82
	83	if (unlikely(*shadow_addr)) {
	84	if (memory_is_poisoned_1(addr + 1))
	85	return true;
	86
	87	if (likely(((addr + 1) & KASAN_SHADOW_MASK) != 0))
	88	return false;
	89
	90	return unlikely((u8 )shadow_addr);
	91	}
	92
	93	return false;
	94	}
	95
	96	static __always_inline bool memory_is_poisoned_4(unsigned long addr)
	97	{
	98	u16 shadow_addr = (u16 )kasan_mem_to_shadow((void *)addr);
99
100	if (unlikely(*shadow_addr)) {
101	if (memory_is_poisoned_1(addr + 3))
102	return true;
103
104	if (likely(((addr + 3) & KASAN_SHADOW_MASK) >= 3))
105	return false;
106
107	return unlikely((u8 )shadow_addr);
108	}
109
110	return false;
111	}
112
113	static __always_inline bool memory_is_poisoned_8(unsigned long addr)
114	{
115	u16 shadow_addr = (u16 )kasan_mem_to_shadow((void *)addr);
116
117	if (unlikely(*shadow_addr)) {
118	if (memory_is_poisoned_1(addr + 7))
119	return true;
120
121	if (likely(((addr + 7) & KASAN_SHADOW_MASK) >= 7))
122	return false;
123
124	return unlikely((u8 )shadow_addr);
125	}
126
127	return false;
128	}
129
130	static __always_inline bool memory_is_poisoned_16(unsigned long addr)
131	{
132	u32 shadow_addr = (u32 )kasan_mem_to_shadow((void *)addr);
133
134	if (unlikely(*shadow_addr)) {
135	u16 shadow_first_bytes = (u16 )shadow_addr;
136	s8 last_byte = (addr + 15) & KASAN_SHADOW_MASK;
137
138	if (unlikely(shadow_first_bytes))
139	return true;
140
141	if (likely(!last_byte))
142	return false;
143
144	return memory_is_poisoned_1(addr + 15);
145	}
146
147	return false;
148	}
149
150	static __always_inline unsigned long bytes_is_zero(const u8 *start,
151	size_t size)
152	{
153	while (size) {
154	if (unlikely(*start))
155	return (unsigned long)start;
156	start++;
157	size--;
158	}
159
160	return 0;
161	}
162
163	static __always_inline unsigned long memory_is_zero(const void *start,
164	const void *end)
165	{
166	unsigned int words;
167	unsigned long ret;
168	unsigned int prefix = (unsigned long)start % 8;
169
170	if (end - start <= 16)
171	return bytes_is_zero(start, end - start);
172
173	if (prefix) {
174	prefix = 8 - prefix;
175	ret = bytes_is_zero(start, prefix);
176	if (unlikely(ret))
177	return ret;
178	start += prefix;
179	}
180
181	words = (end - start) / 8;
182	while (words) {
183	if (unlikely((u64 )start))
184	return bytes_is_zero(start, 8);
185	start += 8;
186	words--;
187	}
188
189	return bytes_is_zero(start, (end - start) % 8);
190	}
191
192	static __always_inline bool memory_is_poisoned_n(unsigned long addr,
193	size_t size)
194	{
195	unsigned long ret;
196
197	ret = memory_is_zero(kasan_mem_to_shadow((void *)addr),
198	kasan_mem_to_shadow((void *)addr + size - 1) + 1);
199
200	if (unlikely(ret)) {
201	unsigned long last_byte = addr + size - 1;
202	s8 last_shadow = (s8 )kasan_mem_to_shadow((void *)last_byte);
203
204	if (unlikely(ret != (unsigned long)last_shadow \|\|
205	((last_byte & KASAN_SHADOW_MASK) >= *last_shadow)))
206	return true;
207	}
208	return false;
209	}
210
211	static __always_inline bool memory_is_poisoned(unsigned long addr, size_t size)
212	{
213	if (__builtin_constant_p(size)) {
214	switch (size) {
215	case 1:
216	return memory_is_poisoned_1(addr);
217	case 2:
218	return memory_is_poisoned_2(addr);
219	case 4:
220	return memory_is_poisoned_4(addr);
221	case 8:
222	return memory_is_poisoned_8(addr);
223	case 16:
224	return memory_is_poisoned_16(addr);
225	default:
226	BUILD_BUG();
227	}
228	}
229
230	return memory_is_poisoned_n(addr, size);
231	}
232
233
234	static __always_inline void check_memory_region(unsigned long addr,
235	size_t size, bool write)
236	{
237	struct kasan_access_info info;
238
239	if (unlikely(size == 0))
240	return;
241
242	if (unlikely((void *)addr <
243	kasan_shadow_to_mem((void *)KASAN_SHADOW_START))) {
244	info.access_addr = (void *)addr;
245	info.access_size = size;
246	info.is_write = write;
247	info.ip = _RET_IP_;
248	kasan_report_user_access(&info);
249	return;
250	}
251
252	if (likely(!memory_is_poisoned(addr, size)))
253	return;
254
255	kasan_report(addr, size, write, _RET_IP_);
256	}
257
393f203f AR	258	void __asan_loadN(unsigned long addr, size_t size);
	259	void __asan_storeN(unsigned long addr, size_t size);
	260
	261	#undef memset
	262	void memset(void addr, int c, size_t len)
	263	{
	264	__asan_storeN((unsigned long)addr, len);
	265
	266	return __memset(addr, c, len);
	267	}
	268
	269	#undef memmove
	270	void memmove(void dest, const void *src, size_t len)
	271	{
	272	__asan_loadN((unsigned long)src, len);
	273	__asan_storeN((unsigned long)dest, len);
	274
	275	return __memmove(dest, src, len);
	276	}
	277
	278	#undef memcpy
	279	void memcpy(void dest, const void *src, size_t len)
	280	{
	281	__asan_loadN((unsigned long)src, len);
	282	__asan_storeN((unsigned long)dest, len);
	283
	284	return __memcpy(dest, src, len);
	285	}
	286
b8c73fc2 AR	287	void kasan_alloc_pages(struct page *page, unsigned int order)
	288	{
	289	if (likely(!PageHighMem(page)))
	290	kasan_unpoison_shadow(page_address(page), PAGE_SIZE << order);
	291	}
	292
	293	void kasan_free_pages(struct page *page, unsigned int order)
	294	{
	295	if (likely(!PageHighMem(page)))
	296	kasan_poison_shadow(page_address(page),
	297	PAGE_SIZE << order,
	298	KASAN_FREE_PAGE);
	299	}
	300
0316bec2 AR	301	void kasan_poison_slab(struct page *page)
	302	{
	303	kasan_poison_shadow(page_address(page),
	304	PAGE_SIZE << compound_order(page),
	305	KASAN_KMALLOC_REDZONE);
	306	}
	307
	308	void kasan_unpoison_object_data(struct kmem_cache cache, void object)
	309	{
	310	kasan_unpoison_shadow(object, cache->object_size);
	311	}
	312
	313	void kasan_poison_object_data(struct kmem_cache cache, void object)
	314	{
	315	kasan_poison_shadow(object,
	316	round_up(cache->object_size, KASAN_SHADOW_SCALE_SIZE),
	317	KASAN_KMALLOC_REDZONE);
	318	}
	319
	320	void kasan_slab_alloc(struct kmem_cache cache, void object)
	321	{
	322	kasan_kmalloc(cache, object, cache->object_size);
	323	}
	324
	325	void kasan_slab_free(struct kmem_cache cache, void object)
	326	{
	327	unsigned long size = cache->object_size;
	328	unsigned long rounded_up_size = round_up(size, KASAN_SHADOW_SCALE_SIZE);
	329
	330	/* RCU slabs could be legally used after free within the RCU period */
	331	if (unlikely(cache->flags & SLAB_DESTROY_BY_RCU))
	332	return;
	333
	334	kasan_poison_shadow(object, rounded_up_size, KASAN_KMALLOC_FREE);
	335	}
	336
	337	void kasan_kmalloc(struct kmem_cache cache, const void object, size_t size)
	338	{
	339	unsigned long redzone_start;
	340	unsigned long redzone_end;
	341
	342	if (unlikely(object == NULL))
	343	return;
	344
	345	redzone_start = round_up((unsigned long)(object + size),
	346	KASAN_SHADOW_SCALE_SIZE);
	347	redzone_end = round_up((unsigned long)object + cache->object_size,
	348	KASAN_SHADOW_SCALE_SIZE);
	349
	350	kasan_unpoison_shadow(object, size);
	351	kasan_poison_shadow((void *)redzone_start, redzone_end - redzone_start,
	352	KASAN_KMALLOC_REDZONE);
	353	}
	354	EXPORT_SYMBOL(kasan_kmalloc);
	355
	356	void kasan_kmalloc_large(const void *ptr, size_t size)
	357	{
	358	struct page *page;
	359	unsigned long redzone_start;
	360	unsigned long redzone_end;
	361
	362	if (unlikely(ptr == NULL))
	363	return;
	364
365	page = virt_to_page(ptr);
366	redzone_start = round_up((unsigned long)(ptr + size),
367	KASAN_SHADOW_SCALE_SIZE);
368	redzone_end = (unsigned long)ptr + (PAGE_SIZE << compound_order(page));
369
370	kasan_unpoison_shadow(ptr, size);
371	kasan_poison_shadow((void *)redzone_start, redzone_end - redzone_start,
372	KASAN_PAGE_REDZONE);
373	}
374
375	void kasan_krealloc(const void *object, size_t size)
376	{
377	struct page *page;
378
379	if (unlikely(object == ZERO_SIZE_PTR))
380	return;
381
382	page = virt_to_head_page(object);
383
384	if (unlikely(!PageSlab(page)))
385	kasan_kmalloc_large(object, size);
386	else
387	kasan_kmalloc(page->slab_cache, object, size);
388	}
389
390	void kasan_kfree_large(const void *ptr)
391	{
392	struct page *page = virt_to_page(ptr);
393
394	kasan_poison_shadow(ptr, PAGE_SIZE << compound_order(page),
395	KASAN_FREE_PAGE);
396	}
397
0b24becc AR	398	#define DEFINE_ASAN_LOAD_STORE(size) \
	399	void __asan_load##size(unsigned long addr) \
	400	{ \
	401	check_memory_region(addr, size, false); \
	402	} \
	403	EXPORT_SYMBOL(__asan_load##size); \
	404	__alias(__asan_load##size) \
	405	void __asan_load##size##_noabort(unsigned long); \
	406	EXPORT_SYMBOL(__asan_load##size##_noabort); \
	407	void __asan_store##size(unsigned long addr) \
	408	{ \
	409	check_memory_region(addr, size, true); \
	410	} \
	411	EXPORT_SYMBOL(__asan_store##size); \
	412	__alias(__asan_store##size) \
	413	void __asan_store##size##_noabort(unsigned long); \
	414	EXPORT_SYMBOL(__asan_store##size##_noabort)
	415
	416	DEFINE_ASAN_LOAD_STORE(1);
	417	DEFINE_ASAN_LOAD_STORE(2);
	418	DEFINE_ASAN_LOAD_STORE(4);
	419	DEFINE_ASAN_LOAD_STORE(8);
	420	DEFINE_ASAN_LOAD_STORE(16);
	421
	422	void __asan_loadN(unsigned long addr, size_t size)
	423	{
	424	check_memory_region(addr, size, false);
	425	}
	426	EXPORT_SYMBOL(__asan_loadN);
	427
	428	__alias(__asan_loadN)
	429	void __asan_loadN_noabort(unsigned long, size_t);
	430	EXPORT_SYMBOL(__asan_loadN_noabort);
	431
	432	void __asan_storeN(unsigned long addr, size_t size)
	433	{
	434	check_memory_region(addr, size, true);
	435	}
	436	EXPORT_SYMBOL(__asan_storeN);
	437
	438	__alias(__asan_storeN)
	439	void __asan_storeN_noabort(unsigned long, size_t);
	440	EXPORT_SYMBOL(__asan_storeN_noabort);
	441
	442	/* to shut up compiler complaints */
	443	void __asan_handle_no_return(void) {}
	444	EXPORT_SYMBOL(__asan_handle_no_return);
786a8959 AR	445
	446	#ifdef CONFIG_MEMORY_HOTPLUG
	447	static int kasan_mem_notifier(struct notifier_block *nb,
	448	unsigned long action, void *data)
	449	{
	450	return (action == MEM_GOING_ONLINE) ? NOTIFY_BAD : NOTIFY_OK;
	451	}
	452
	453	static int __init kasan_memhotplug_init(void)
	454	{
	455	pr_err("WARNING: KASan doesn't support memory hot-add\n");
	456	pr_err("Memory hot-add will be disabled\n");
	457
	458	hotplug_memory_notifier(kasan_mem_notifier, 0);
	459
	460	return 0;
	461	}
	462
	463	module_init(kasan_memhotplug_init);
	464	#endif