1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
|
// SPDX-License-Identifier: GPL-2.0
/*
* KMSAN hooks for kernel subsystems.
*
* These functions handle creation of KMSAN metadata for memory allocations.
*
* Copyright (C) 2018-2022 Google LLC
* Author: Alexander Potapenko <glider@google.com>
*
*/
#include <linux/cacheflush.h>
#include <linux/gfp.h>
#include <linux/kmsan.h>
#include <linux/mm.h>
#include <linux/mm_types.h>
#include <linux/slab.h>
#include <linux/uaccess.h>
#include "../internal.h"
#include "../slab.h"
#include "kmsan.h"
/*
* Instrumented functions shouldn't be called under
* kmsan_enter_runtime()/kmsan_leave_runtime(), because this will lead to
* skipping effects of functions like memset() inside instrumented code.
*/
static unsigned long vmalloc_shadow(unsigned long addr)
{
return (unsigned long)kmsan_get_metadata((void *)addr,
KMSAN_META_SHADOW);
}
static unsigned long vmalloc_origin(unsigned long addr)
{
return (unsigned long)kmsan_get_metadata((void *)addr,
KMSAN_META_ORIGIN);
}
void kmsan_vunmap_range_noflush(unsigned long start, unsigned long end)
{
__vunmap_range_noflush(vmalloc_shadow(start), vmalloc_shadow(end));
__vunmap_range_noflush(vmalloc_origin(start), vmalloc_origin(end));
flush_cache_vmap(vmalloc_shadow(start), vmalloc_shadow(end));
flush_cache_vmap(vmalloc_origin(start), vmalloc_origin(end));
}
/*
* This function creates new shadow/origin pages for the physical pages mapped
* into the virtual memory. If those physical pages already had shadow/origin,
* those are ignored.
*/
void kmsan_ioremap_page_range(unsigned long start, unsigned long end,
phys_addr_t phys_addr, pgprot_t prot,
unsigned int page_shift)
{
gfp_t gfp_mask = GFP_KERNEL | __GFP_ZERO;
struct page *shadow, *origin;
unsigned long off = 0;
int nr;
if (!kmsan_enabled || kmsan_in_runtime())
return;
nr = (end - start) / PAGE_SIZE;
kmsan_enter_runtime();
for (int i = 0; i < nr; i++, off += PAGE_SIZE) {
shadow = alloc_pages(gfp_mask, 1);
origin = alloc_pages(gfp_mask, 1);
__vmap_pages_range_noflush(
vmalloc_shadow(start + off),
vmalloc_shadow(start + off + PAGE_SIZE), prot, &shadow,
PAGE_SHIFT);
__vmap_pages_range_noflush(
vmalloc_origin(start + off),
vmalloc_origin(start + off + PAGE_SIZE), prot, &origin,
PAGE_SHIFT);
}
flush_cache_vmap(vmalloc_shadow(start), vmalloc_shadow(end));
flush_cache_vmap(vmalloc_origin(start), vmalloc_origin(end));
kmsan_leave_runtime();
}
void kmsan_iounmap_page_range(unsigned long start, unsigned long end)
{
unsigned long v_shadow, v_origin;
struct page *shadow, *origin;
int nr;
if (!kmsan_enabled || kmsan_in_runtime())
return;
nr = (end - start) / PAGE_SIZE;
kmsan_enter_runtime();
v_shadow = (unsigned long)vmalloc_shadow(start);
v_origin = (unsigned long)vmalloc_origin(start);
for (int i = 0; i < nr;
i++, v_shadow += PAGE_SIZE, v_origin += PAGE_SIZE) {
shadow = kmsan_vmalloc_to_page_or_null((void *)v_shadow);
origin = kmsan_vmalloc_to_page_or_null((void *)v_origin);
__vunmap_range_noflush(v_shadow, vmalloc_shadow(end));
__vunmap_range_noflush(v_origin, vmalloc_origin(end));
if (shadow)
__free_pages(shadow, 1);
if (origin)
__free_pages(origin, 1);
}
flush_cache_vmap(vmalloc_shadow(start), vmalloc_shadow(end));
flush_cache_vmap(vmalloc_origin(start), vmalloc_origin(end));
kmsan_leave_runtime();
}
/* Functions from kmsan-checks.h follow. */
void kmsan_poison_memory(const void *address, size_t size, gfp_t flags)
{
if (!kmsan_enabled || kmsan_in_runtime())
return;
kmsan_enter_runtime();
/* The users may want to poison/unpoison random memory. */
kmsan_internal_poison_memory((void *)address, size, flags,
KMSAN_POISON_NOCHECK);
kmsan_leave_runtime();
}
EXPORT_SYMBOL(kmsan_poison_memory);
void kmsan_unpoison_memory(const void *address, size_t size)
{
unsigned long ua_flags;
if (!kmsan_enabled || kmsan_in_runtime())
return;
ua_flags = user_access_save();
kmsan_enter_runtime();
/* The users may want to poison/unpoison random memory. */
kmsan_internal_unpoison_memory((void *)address, size,
KMSAN_POISON_NOCHECK);
kmsan_leave_runtime();
user_access_restore(ua_flags);
}
EXPORT_SYMBOL(kmsan_unpoison_memory);
void kmsan_check_memory(const void *addr, size_t size)
{
if (!kmsan_enabled)
return;
return kmsan_internal_check_memory((void *)addr, size, /*user_addr*/ 0,
REASON_ANY);
}
EXPORT_SYMBOL(kmsan_check_memory);
|
