1b163bb742a099c1808907b513ae39068b63b1692Vladimir Marko/* 2b163bb742a099c1808907b513ae39068b63b1692Vladimir Marko * Copyright (C) 2015 The Android Open Source Project 3b163bb742a099c1808907b513ae39068b63b1692Vladimir Marko * 4b163bb742a099c1808907b513ae39068b63b1692Vladimir Marko * Licensed under the Apache License, Version 2.0 (the "License"); 5b163bb742a099c1808907b513ae39068b63b1692Vladimir Marko * you may not use this file except in compliance with the License. 6b163bb742a099c1808907b513ae39068b63b1692Vladimir Marko * You may obtain a copy of the License at 7b163bb742a099c1808907b513ae39068b63b1692Vladimir Marko * 8b163bb742a099c1808907b513ae39068b63b1692Vladimir Marko * http://www.apache.org/licenses/LICENSE-2.0 9b163bb742a099c1808907b513ae39068b63b1692Vladimir Marko * 10b163bb742a099c1808907b513ae39068b63b1692Vladimir Marko * Unless required by applicable law or agreed to in writing, software 11b163bb742a099c1808907b513ae39068b63b1692Vladimir Marko * distributed under the License is distributed on an "AS IS" BASIS, 12b163bb742a099c1808907b513ae39068b63b1692Vladimir Marko * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13b163bb742a099c1808907b513ae39068b63b1692Vladimir Marko * See the License for the specific language governing permissions and 14b163bb742a099c1808907b513ae39068b63b1692Vladimir Marko * limitations under the License. 15b163bb742a099c1808907b513ae39068b63b1692Vladimir Marko */ 16b163bb742a099c1808907b513ae39068b63b1692Vladimir Marko 17b163bb742a099c1808907b513ae39068b63b1692Vladimir Marko#include "linker/arm/relative_patcher_thumb2.h" 18b163bb742a099c1808907b513ae39068b63b1692Vladimir Marko 193d21bdf8894e780d349c481e5c9e29fe1556051cMathieu Chartier#include "art_method.h" 20b163bb742a099c1808907b513ae39068b63b1692Vladimir Marko#include "compiled_method.h" 21b163bb742a099c1808907b513ae39068b63b1692Vladimir Marko#include "utils/arm/assembler_thumb2.h" 22b163bb742a099c1808907b513ae39068b63b1692Vladimir Marko 23b163bb742a099c1808907b513ae39068b63b1692Vladimir Markonamespace art { 24b163bb742a099c1808907b513ae39068b63b1692Vladimir Markonamespace linker { 25b163bb742a099c1808907b513ae39068b63b1692Vladimir Marko 26b163bb742a099c1808907b513ae39068b63b1692Vladimir MarkoThumb2RelativePatcher::Thumb2RelativePatcher(RelativePatcherTargetProvider* provider) 27b163bb742a099c1808907b513ae39068b63b1692Vladimir Marko : ArmBaseRelativePatcher(provider, kThumb2, CompileThunkCode(), 28b163bb742a099c1808907b513ae39068b63b1692Vladimir Marko kMaxPositiveDisplacement, kMaxNegativeDisplacement) { 29b163bb742a099c1808907b513ae39068b63b1692Vladimir Marko} 30b163bb742a099c1808907b513ae39068b63b1692Vladimir Marko 31b163bb742a099c1808907b513ae39068b63b1692Vladimir Markovoid Thumb2RelativePatcher::PatchCall(std::vector<uint8_t>* code, uint32_t literal_offset, 32b163bb742a099c1808907b513ae39068b63b1692Vladimir Marko uint32_t patch_offset, uint32_t target_offset) { 33b163bb742a099c1808907b513ae39068b63b1692Vladimir Marko DCHECK_LE(literal_offset + 4u, code->size()); 34b163bb742a099c1808907b513ae39068b63b1692Vladimir Marko DCHECK_EQ(literal_offset & 1u, 0u); 35b163bb742a099c1808907b513ae39068b63b1692Vladimir Marko DCHECK_EQ(patch_offset & 1u, 0u); 36b163bb742a099c1808907b513ae39068b63b1692Vladimir Marko DCHECK_EQ(target_offset & 1u, 1u); // Thumb2 mode bit. 37b163bb742a099c1808907b513ae39068b63b1692Vladimir Marko uint32_t displacement = CalculateDisplacement(patch_offset, target_offset & ~1u); 38b163bb742a099c1808907b513ae39068b63b1692Vladimir Marko displacement -= kPcDisplacement; // The base PC is at the end of the 4-byte patch. 39b163bb742a099c1808907b513ae39068b63b1692Vladimir Marko DCHECK_EQ(displacement & 1u, 0u); 40b163bb742a099c1808907b513ae39068b63b1692Vladimir Marko DCHECK((displacement >> 24) == 0u || (displacement >> 24) == 255u); // 25-bit signed. 41b163bb742a099c1808907b513ae39068b63b1692Vladimir Marko uint32_t signbit = (displacement >> 31) & 0x1; 42b163bb742a099c1808907b513ae39068b63b1692Vladimir Marko uint32_t i1 = (displacement >> 23) & 0x1; 43b163bb742a099c1808907b513ae39068b63b1692Vladimir Marko uint32_t i2 = (displacement >> 22) & 0x1; 44b163bb742a099c1808907b513ae39068b63b1692Vladimir Marko uint32_t imm10 = (displacement >> 12) & 0x03ff; 45b163bb742a099c1808907b513ae39068b63b1692Vladimir Marko uint32_t imm11 = (displacement >> 1) & 0x07ff; 46b163bb742a099c1808907b513ae39068b63b1692Vladimir Marko uint32_t j1 = i1 ^ (signbit ^ 1); 47b163bb742a099c1808907b513ae39068b63b1692Vladimir Marko uint32_t j2 = i2 ^ (signbit ^ 1); 48b163bb742a099c1808907b513ae39068b63b1692Vladimir Marko uint32_t value = (signbit << 26) | (j1 << 13) | (j2 << 11) | (imm10 << 16) | imm11; 49b163bb742a099c1808907b513ae39068b63b1692Vladimir Marko value |= 0xf000d000; // BL 50b163bb742a099c1808907b513ae39068b63b1692Vladimir Marko 51b163bb742a099c1808907b513ae39068b63b1692Vladimir Marko // Check that we're just overwriting an existing BL. 52e5c76c515a481074aaa6b869aa16490a47ba98bcVladimir Marko DCHECK_EQ(GetInsn32(code, literal_offset) & 0xf800d000, 0xf000d000); 53b163bb742a099c1808907b513ae39068b63b1692Vladimir Marko // Write the new BL. 54e5c76c515a481074aaa6b869aa16490a47ba98bcVladimir Marko SetInsn32(code, literal_offset, value); 55b163bb742a099c1808907b513ae39068b63b1692Vladimir Marko} 56b163bb742a099c1808907b513ae39068b63b1692Vladimir Marko 57e5c76c515a481074aaa6b869aa16490a47ba98bcVladimir Markovoid Thumb2RelativePatcher::PatchDexCacheReference(std::vector<uint8_t>* code, 58e5c76c515a481074aaa6b869aa16490a47ba98bcVladimir Marko const LinkerPatch& patch, 59e5c76c515a481074aaa6b869aa16490a47ba98bcVladimir Marko uint32_t patch_offset, 60e5c76c515a481074aaa6b869aa16490a47ba98bcVladimir Marko uint32_t target_offset) { 61e5c76c515a481074aaa6b869aa16490a47ba98bcVladimir Marko uint32_t literal_offset = patch.LiteralOffset(); 62e5c76c515a481074aaa6b869aa16490a47ba98bcVladimir Marko uint32_t pc_literal_offset = patch.PcInsnOffset(); 63e5c76c515a481074aaa6b869aa16490a47ba98bcVladimir Marko uint32_t pc_base = patch_offset + (pc_literal_offset - literal_offset) + 4u /* PC adjustment */; 64e5c76c515a481074aaa6b869aa16490a47ba98bcVladimir Marko uint32_t diff = target_offset - pc_base; 65e5c76c515a481074aaa6b869aa16490a47ba98bcVladimir Marko 66e5c76c515a481074aaa6b869aa16490a47ba98bcVladimir Marko uint32_t insn = GetInsn32(code, literal_offset); 67e5c76c515a481074aaa6b869aa16490a47ba98bcVladimir Marko DCHECK_EQ(insn & 0xff7ff0ffu, 0xf2400000u); // MOVW/MOVT, unpatched (imm16 == 0). 68e5c76c515a481074aaa6b869aa16490a47ba98bcVladimir Marko uint32_t diff16 = ((insn & 0x00800000u) != 0u) ? (diff >> 16) : (diff & 0xffffu); 69e5c76c515a481074aaa6b869aa16490a47ba98bcVladimir Marko uint32_t imm4 = (diff16 >> 12) & 0xfu; 70e5c76c515a481074aaa6b869aa16490a47ba98bcVladimir Marko uint32_t imm = (diff16 >> 11) & 0x1u; 71e5c76c515a481074aaa6b869aa16490a47ba98bcVladimir Marko uint32_t imm3 = (diff16 >> 8) & 0x7u; 72e5c76c515a481074aaa6b869aa16490a47ba98bcVladimir Marko uint32_t imm8 = diff16 & 0xffu; 73e5c76c515a481074aaa6b869aa16490a47ba98bcVladimir Marko insn = (insn & 0xfbf08f00u) | (imm << 26) | (imm4 << 16) | (imm3 << 12) | imm8; 74e5c76c515a481074aaa6b869aa16490a47ba98bcVladimir Marko SetInsn32(code, literal_offset, insn); 75b163bb742a099c1808907b513ae39068b63b1692Vladimir Marko} 76b163bb742a099c1808907b513ae39068b63b1692Vladimir Marko 77b163bb742a099c1808907b513ae39068b63b1692Vladimir Markostd::vector<uint8_t> Thumb2RelativePatcher::CompileThunkCode() { 78b163bb742a099c1808907b513ae39068b63b1692Vladimir Marko // The thunk just uses the entry point in the ArtMethod. This works even for calls 79b163bb742a099c1808907b513ae39068b63b1692Vladimir Marko // to the generic JNI and interpreter trampolines. 80b163bb742a099c1808907b513ae39068b63b1692Vladimir Marko arm::Thumb2Assembler assembler; 81b163bb742a099c1808907b513ae39068b63b1692Vladimir Marko assembler.LoadFromOffset( 82b163bb742a099c1808907b513ae39068b63b1692Vladimir Marko arm::kLoadWord, arm::PC, arm::R0, 833d21bdf8894e780d349c481e5c9e29fe1556051cMathieu Chartier ArtMethod::EntryPointFromQuickCompiledCodeOffset(kArmPointerSize).Int32Value()); 84b163bb742a099c1808907b513ae39068b63b1692Vladimir Marko assembler.bkpt(0); 85b163bb742a099c1808907b513ae39068b63b1692Vladimir Marko std::vector<uint8_t> thunk_code(assembler.CodeSize()); 86b163bb742a099c1808907b513ae39068b63b1692Vladimir Marko MemoryRegion code(thunk_code.data(), thunk_code.size()); 87b163bb742a099c1808907b513ae39068b63b1692Vladimir Marko assembler.FinalizeInstructions(code); 88b163bb742a099c1808907b513ae39068b63b1692Vladimir Marko return thunk_code; 89b163bb742a099c1808907b513ae39068b63b1692Vladimir Marko} 90b163bb742a099c1808907b513ae39068b63b1692Vladimir Marko 91e5c76c515a481074aaa6b869aa16490a47ba98bcVladimir Markovoid Thumb2RelativePatcher::SetInsn32(std::vector<uint8_t>* code, uint32_t offset, uint32_t value) { 92e5c76c515a481074aaa6b869aa16490a47ba98bcVladimir Marko DCHECK_LE(offset + 4u, code->size()); 93e5c76c515a481074aaa6b869aa16490a47ba98bcVladimir Marko DCHECK_EQ(offset & 1u, 0u); 94e5c76c515a481074aaa6b869aa16490a47ba98bcVladimir Marko uint8_t* addr = &(*code)[offset]; 95e5c76c515a481074aaa6b869aa16490a47ba98bcVladimir Marko addr[0] = (value >> 16) & 0xff; 96e5c76c515a481074aaa6b869aa16490a47ba98bcVladimir Marko addr[1] = (value >> 24) & 0xff; 97e5c76c515a481074aaa6b869aa16490a47ba98bcVladimir Marko addr[2] = (value >> 0) & 0xff; 98e5c76c515a481074aaa6b869aa16490a47ba98bcVladimir Marko addr[3] = (value >> 8) & 0xff; 99e5c76c515a481074aaa6b869aa16490a47ba98bcVladimir Marko} 100e5c76c515a481074aaa6b869aa16490a47ba98bcVladimir Marko 101e5c76c515a481074aaa6b869aa16490a47ba98bcVladimir Markouint32_t Thumb2RelativePatcher::GetInsn32(ArrayRef<const uint8_t> code, uint32_t offset) { 102e5c76c515a481074aaa6b869aa16490a47ba98bcVladimir Marko DCHECK_LE(offset + 4u, code.size()); 103e5c76c515a481074aaa6b869aa16490a47ba98bcVladimir Marko DCHECK_EQ(offset & 1u, 0u); 104e5c76c515a481074aaa6b869aa16490a47ba98bcVladimir Marko const uint8_t* addr = &code[offset]; 105e5c76c515a481074aaa6b869aa16490a47ba98bcVladimir Marko return 106e5c76c515a481074aaa6b869aa16490a47ba98bcVladimir Marko (static_cast<uint32_t>(addr[0]) << 16) + 107e5c76c515a481074aaa6b869aa16490a47ba98bcVladimir Marko (static_cast<uint32_t>(addr[1]) << 24) + 108e5c76c515a481074aaa6b869aa16490a47ba98bcVladimir Marko (static_cast<uint32_t>(addr[2]) << 0)+ 109e5c76c515a481074aaa6b869aa16490a47ba98bcVladimir Marko (static_cast<uint32_t>(addr[3]) << 8); 110e5c76c515a481074aaa6b869aa16490a47ba98bcVladimir Marko} 111e5c76c515a481074aaa6b869aa16490a47ba98bcVladimir Marko 112e5c76c515a481074aaa6b869aa16490a47ba98bcVladimir Markotemplate <typename Alloc> 113e5c76c515a481074aaa6b869aa16490a47ba98bcVladimir Markouint32_t Thumb2RelativePatcher::GetInsn32(std::vector<uint8_t, Alloc>* code, uint32_t offset) { 114e5c76c515a481074aaa6b869aa16490a47ba98bcVladimir Marko return GetInsn32(ArrayRef<const uint8_t>(*code), offset); 115e5c76c515a481074aaa6b869aa16490a47ba98bcVladimir Marko} 116e5c76c515a481074aaa6b869aa16490a47ba98bcVladimir Marko 117b163bb742a099c1808907b513ae39068b63b1692Vladimir Marko} // namespace linker 118b163bb742a099c1808907b513ae39068b63b1692Vladimir Marko} // namespace art 119