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
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
|
//===---- AccessibleFunction.cpp - Swift protocol conformance checking ----===//
//
// This source file is part of the Swift.org open source project
//
// Copyright (c) 2014 - 2021 Apple Inc. and the Swift project authors
// Licensed under Apache License v2.0 with Runtime Library Exception
//
// See https://swift.org/LICENSE.txt for license information
// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
//
//===----------------------------------------------------------------------===//
//
// Checking and caching of Swift accessible functions.
//
//===----------------------------------------------------------------------===//
#include "ImageInspection.h"
#include "Private.h"
#include "swift/Basic/Lazy.h"
#include "swift/Demangling/Demangler.h"
#include "swift/Runtime/AccessibleFunction.h"
#include "swift/Runtime/Concurrent.h"
#include "swift/Runtime/Metadata.h"
#include "Tracing.h"
#include <cstdint>
#include <new>
using namespace swift;
#pragma mark Accessible function cache
namespace {
struct AccessibleFunctionsSection {
const AccessibleFunctionRecord *__ptrauth_swift_accessible_function_record
Begin;
const AccessibleFunctionRecord *__ptrauth_swift_accessible_function_record
End;
AccessibleFunctionsSection(const AccessibleFunctionRecord *begin,
const AccessibleFunctionRecord *end)
: Begin(begin), End(end) {}
AccessibleFunctionsSection(const void *ptr, uintptr_t size) {
auto bytes = reinterpret_cast<const char *>(ptr);
Begin = reinterpret_cast<const AccessibleFunctionRecord *>(ptr);
End = reinterpret_cast<const AccessibleFunctionRecord *>(bytes + size);
}
const AccessibleFunctionRecord *begin() const { return Begin; }
const AccessibleFunctionRecord *end() const { return End; }
};
struct AccessibleFunctionCacheEntry {
private:
const char *Name;
size_t NameLength;
const AccessibleFunctionRecord *__ptrauth_swift_accessible_function_record R;
public:
AccessibleFunctionCacheEntry(llvm::StringRef name,
const AccessibleFunctionRecord *record)
: R(record) {
char *Name = reinterpret_cast<char *>(malloc(name.size()));
memcpy(Name, name.data(), name.size());
this->Name = Name;
this->NameLength = name.size();
}
const AccessibleFunctionRecord *getRecord() const { return R; }
bool matchesKey(llvm::StringRef name) {
return name == llvm::StringRef{Name, NameLength};
}
friend llvm::hash_code hash_value(const AccessibleFunctionCacheEntry &value) {
return hash_value(llvm::StringRef{value.Name, value.NameLength});
}
template <class... T>
static size_t getExtraAllocationSize(T &&...ignored) {
return 0;
}
};
struct AccessibleFunctionsState {
ConcurrentReadableHashMap<AccessibleFunctionCacheEntry> Cache;
ConcurrentReadableArray<AccessibleFunctionsSection> SectionsToScan;
AccessibleFunctionsState() {
initializeAccessibleFunctionsLookup();
}
};
static Lazy<AccessibleFunctionsState> Functions;
} // end anonymous namespace
static void _registerAccessibleFunctions(AccessibleFunctionsState &C,
AccessibleFunctionsSection section) {
C.SectionsToScan.push_back(section);
}
void swift::addImageAccessibleFunctionsBlockCallbackUnsafe(
const void *baseAddress, const void *functions, uintptr_t size) {
assert(
size % sizeof(AccessibleFunctionRecord) == 0 &&
"accessible function section not a multiple of AccessibleFunctionRecord");
auto &C = Functions.unsafeGetAlreadyInitialized();
_registerAccessibleFunctions(C, AccessibleFunctionsSection{functions, size});
}
void swift::addImageAccessibleFunctionsBlockCallback(
const void *baseAddress, const void *functions, uintptr_t size) {
Functions.get();
addImageAccessibleFunctionsBlockCallbackUnsafe(baseAddress, functions, size);
}
// TODO(distributed): expose dumping records via a flag
LLVM_ATTRIBUTE_UNUSED
static void _dumpAccessibleFunctionRecords() {
auto &S = Functions.get();
fprintf(stderr, "==== Accessible Function Records ====\n");
int count = 0;
for (const auto §ion : S.SectionsToScan.snapshot()) {
for (auto &record : section) {
auto recordName =
swift::Demangle::makeSymbolicMangledNameStringRef(record.Name.get());
fprintf(stderr, "Record name: %s\n", recordName.data());
fprintf(stderr, " Function Ptr: %p\n", record.Function.get());
fprintf(stderr, " Flags.IsDistributed: %d\n", record.Flags.isDistributed());
++count;
}
}
fprintf(stderr, "Record count: %d\n", count);
fprintf(stderr, "==== End of Accessible Function Records ====\n");
}
static const AccessibleFunctionRecord *
_searchForFunctionRecord(AccessibleFunctionsState &S, llvm::StringRef name) {
auto traceState = runtime::trace::accessible_function_scan_begin(name);
for (const auto §ion : S.SectionsToScan.snapshot()) {
for (auto &record : section) {
auto recordName =
swift::Demangle::makeSymbolicMangledNameStringRef(record.Name.get());
if (recordName == name)
return traceState.end(&record);
}
}
return nullptr;
}
SWIFT_RUNTIME_STDLIB_SPI
const AccessibleFunctionRecord *
swift::runtime::swift_findAccessibleFunction(const char *targetNameStart,
size_t targetNameLength) {
auto &S = Functions.get();
llvm::StringRef name{targetNameStart, targetNameLength};
// Look for an existing entry.
{
auto snapshot = S.Cache.snapshot();
if (auto E = snapshot.find(name))
return E->getRecord();
}
// If entry doesn't exist (either record doesn't exist, hasn't been loaded, or
// requested yet), let's try to find it and add to the cache.
auto *record = _searchForFunctionRecord(S, name);
if (record) {
S.Cache.getOrInsert(
name, [&](AccessibleFunctionCacheEntry *entry, bool created) {
if (created)
::new (entry) AccessibleFunctionCacheEntry{name, record};
return true;
});
}
return record;
}
|
