[linux-2.6-block.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/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/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);
}

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));
	return ret ? 0 : -ENOMEM;
}

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