1 /*
2 * Copyright (C) 2015 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 #include "linker/x86_64/relative_patcher_x86_64.h"
18
19 #include "compiled_method.h"
20
21 namespace art {
22 namespace linker {
23
PatchPcRelativeReference(std::vector<uint8_t> * code,const LinkerPatch & patch,uint32_t patch_offset,uint32_t target_offset)24 void X86_64RelativePatcher::PatchPcRelativeReference(std::vector<uint8_t>* code,
25 const LinkerPatch& patch,
26 uint32_t patch_offset,
27 uint32_t target_offset) {
28 DCHECK_LE(patch.LiteralOffset() + 4u, code->size());
29 // Unsigned arithmetic with its well-defined overflow behavior is just fine here.
30 uint32_t displacement = target_offset - patch_offset;
31 displacement -= kPcDisplacement; // The base PC is at the end of the 4-byte patch.
32
33 typedef __attribute__((__aligned__(1))) int32_t unaligned_int32_t;
34 reinterpret_cast<unaligned_int32_t*>(&(*code)[patch.LiteralOffset()])[0] = displacement;
35 }
36
PatchBakerReadBarrierBranch(std::vector<uint8_t> * code ATTRIBUTE_UNUSED,const LinkerPatch & patch ATTRIBUTE_UNUSED,uint32_t patch_offset ATTRIBUTE_UNUSED)37 void X86_64RelativePatcher::PatchBakerReadBarrierBranch(std::vector<uint8_t>* code ATTRIBUTE_UNUSED,
38 const LinkerPatch& patch ATTRIBUTE_UNUSED,
39 uint32_t patch_offset ATTRIBUTE_UNUSED) {
40 LOG(FATAL) << "UNIMPLEMENTED";
41 }
42
43 } // namespace linker
44 } // namespace art
45