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
base / allocator / partition_allocator / src / partition_alloc / shim / malloc_zone_functions_apple.h [blame]
// Copyright 2017 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef PARTITION_ALLOC_SHIM_MALLOC_ZONE_FUNCTIONS_APPLE_H_
#define PARTITION_ALLOC_SHIM_MALLOC_ZONE_FUNCTIONS_APPLE_H_
#include "partition_alloc/buildflags.h"
#if PA_BUILDFLAG(USE_ALLOCATOR_SHIM)
#include <malloc/malloc.h>
#include <cstddef>
#include "partition_alloc/partition_alloc_base/component_export.h"
#include "partition_alloc/partition_alloc_base/immediate_crash.h"
#include "partition_alloc/third_party/apple_apsl/malloc.h"
namespace allocator_shim {
typedef void* (*malloc_type)(struct _malloc_zone_t* zone, size_t size);
typedef void* (*calloc_type)(struct _malloc_zone_t* zone,
size_t num_items,
size_t size);
typedef void* (*valloc_type)(struct _malloc_zone_t* zone, size_t size);
typedef void (*free_type)(struct _malloc_zone_t* zone, void* ptr);
typedef void* (*realloc_type)(struct _malloc_zone_t* zone,
void* ptr,
size_t size);
typedef void* (*memalign_type)(struct _malloc_zone_t* zone,
size_t alignment,
size_t size);
typedef unsigned (*batch_malloc_type)(struct _malloc_zone_t* zone,
size_t size,
void** results,
unsigned num_requested);
typedef void (*batch_free_type)(struct _malloc_zone_t* zone,
void** to_be_freed,
unsigned num_to_be_freed);
typedef void (*free_definite_size_type)(struct _malloc_zone_t* zone,
void* ptr,
size_t size);
typedef void (*try_free_default_type)(struct _malloc_zone_t* zone, void* ptr);
typedef size_t (*size_fn_type)(struct _malloc_zone_t* zone, const void* ptr);
typedef size_t (*good_size_fn_type)(struct _malloc_zone_t* zone, size_t size);
typedef boolean_t (*claimed_address_type)(struct _malloc_zone_t* zone,
void* ptr);
struct MallocZoneFunctions {
malloc_type malloc;
calloc_type calloc;
valloc_type valloc;
free_type free;
realloc_type realloc;
memalign_type memalign;
batch_malloc_type batch_malloc;
batch_free_type batch_free;
free_definite_size_type free_definite_size;
try_free_default_type try_free_default;
size_fn_type size;
good_size_fn_type good_size;
claimed_address_type claimed_address;
const ChromeMallocZone* context;
};
PA_COMPONENT_EXPORT(ALLOCATOR_SHIM)
void StoreZoneFunctions(const ChromeMallocZone* zone,
MallocZoneFunctions* functions);
static constexpr int kMaxZoneCount = 30;
PA_COMPONENT_EXPORT(ALLOCATOR_SHIM)
extern MallocZoneFunctions g_malloc_zones[kMaxZoneCount];
// The array g_malloc_zones stores all information about malloc zones before
// they are shimmed. This information needs to be accessed during dispatch back
// into the zone, and additional zones may be added later in the execution fo
// the program, so the array needs to be both thread-safe and high-performance.
//
// We begin by creating an array of MallocZoneFunctions of fixed size. We will
// never modify the container, which provides thread-safety to iterators. When
// we want to add a MallocZoneFunctions to the container, we:
// 1. Fill in all the fields.
// 2. Update the total zone count.
// 3. Insert a memory barrier.
// 4. Insert our shim.
//
// Each MallocZoneFunctions is uniquely identified by |context|, which is a
// pointer to the original malloc zone. When we wish to dispatch back to the
// original malloc zones, we iterate through the array, looking for a matching
// |context|.
//
// Most allocations go through the default allocator. We will ensure that the
// default allocator is stored as the first MallocZoneFunctions.
//
// Returns whether the zone was successfully stored.
PA_COMPONENT_EXPORT(ALLOCATOR_SHIM)
bool StoreMallocZone(ChromeMallocZone* zone);
PA_COMPONENT_EXPORT(ALLOCATOR_SHIM)
bool IsMallocZoneAlreadyStored(ChromeMallocZone* zone);
PA_COMPONENT_EXPORT(ALLOCATOR_SHIM)
bool DoesMallocZoneNeedReplacing(ChromeMallocZone* zone,
const MallocZoneFunctions* functions);
PA_COMPONENT_EXPORT(ALLOCATOR_SHIM) int GetMallocZoneCountForTesting();
PA_COMPONENT_EXPORT(ALLOCATOR_SHIM) void ClearAllMallocZonesForTesting();
inline MallocZoneFunctions& GetFunctionsForZone(void* zone) {
for (unsigned int i = 0; i < kMaxZoneCount; ++i) {
if (g_malloc_zones[i].context == zone) {
return g_malloc_zones[i];
}
}
PA_IMMEDIATE_CRASH();
}
} // namespace allocator_shim
#endif // PA_BUILDFLAG(USE_ALLOCATOR_SHIM)
#endif // PARTITION_ALLOC_SHIM_MALLOC_ZONE_FUNCTIONS_APPLE_H_