1 /*
2  * Copyright (C) 2023 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #ifndef BERBERIS_LOADER_PROXY_LIBRARY_BUILDER_H_
18 #define BERBERIS_LOADER_PROXY_LIBRARY_BUILDER_H_
19 
20 #include "berberis/guest_state/guest_addr.h"
21 #include "berberis/runtime_primitives/host_function_wrapper_impl.h"  // TrampolineFunc
22 
23 namespace berberis {
24 
25 struct ThreadState;
26 
27 struct KnownTrampoline {
28   const char* name;
29   TrampolineFunc marshal_and_call;
30   void* thunk;
31 };
32 
33 struct KnownVariable {
34   const char* name;
35   size_t size;
36 };
37 
38 // TODO(eaeltsin): these are stubs used by known trampolines, consider killing!
39 void DoBadThunk();
40 void DoBadTrampoline(HostCode callee, ThreadState* state);
41 
42 class ProxyLibraryBuilder {
43  public:
44   ProxyLibraryBuilder() = default;
45 
46   void Build(const char* library_name,
47              size_t size_translation,
48              const KnownTrampoline* translations,
49              size_t size_data_symbols,
50              const KnownVariable* variables);
51 
52   void InterceptSymbol(GuestAddr guest_addr, const char* name);
53 
54  private:
55   const char* library_name_ = nullptr;
56   size_t num_functions_ = 0;
57   const KnownTrampoline* functions_ = nullptr;
58   size_t num_variables_ = 0;
59   const KnownVariable* variables_ = nullptr;
60   void* handle_ = nullptr;
61 };
62 
63 // Assume kKnownTrampolines and kKnownVariables defined.
64 #define DEFINE_INIT_PROXY_LIBRARY(soname)                                    \
65   extern "C" void InitProxyLibrary(ProxyLibraryBuilder* builder) {           \
66     builder->Build(soname,                                                   \
67                    sizeof(kKnownTrampolines) / sizeof(kKnownTrampolines[0]), \
68                    kKnownTrampolines,                                        \
69                    sizeof(kKnownVariables) / sizeof(kKnownVariables[0]),     \
70                    kKnownVariables);                                         \
71   }
72 
73 }  // namespace berberis
74 
75 #endif  // BERBERIS_LOADER_PROXY_LIBRARY_BUILDER_H_
76