| /* |
| * Copyright 2011, The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| #include "StubLayout.h" |
| |
| #include "utils/flush_cpu_cache.h" |
| #include "utils/raw_ostream.h" |
| #include "utils/rsl_assert.h" |
| |
| #include <stdint.h> |
| #include <stdlib.h> |
| |
| StubLayout::StubLayout() : table(nullptr), count(0) { |
| } |
| |
| void StubLayout::initStubTable(unsigned char *table_, size_t count_) { |
| table = table_; |
| count = count_; |
| } |
| |
| void *StubLayout::allocateStub(void *addr) { |
| // Check if we have created this stub or not. |
| std::map<void *, void *>::iterator index_iter = stub_index.find(addr); |
| |
| if (index_iter != stub_index.end()) { |
| return index_iter->second; |
| } |
| |
| // We have to create a new stub |
| if (count == 0) { |
| // No free stub slot is available |
| return nullptr; |
| } |
| |
| // Initialize the stub |
| unsigned char *stub = table; |
| setStubAddress(stub, addr); |
| stub_index.insert(std::make_pair(addr, stub)); |
| |
| // Increase the free stub slot pointer |
| table += getUnitStubSize(); |
| count--; |
| |
| return stub; |
| } |
| |
| size_t StubLayout::calcStubTableSize(size_t count) const { |
| return count * getUnitStubSize(); |
| } |
| |
| size_t StubLayoutAARCH64::getUnitStubSize() const { |
| return 16; |
| } |
| |
| void StubLayoutAARCH64::setStubAddress(void *stub_, void *addr) { |
| uint8_t *stub = (uint8_t *)stub_; |
| |
| // First instruction: |
| // ldr x16,[pc,#8] LDR literal (pc relative) |
| // +--+---+-+--+-------------------+-----+ |
| // |01|011|0|00| (#8 >> 2) = 10 |10000| |
| // +--+---+-+--+-------------------+-----+ |
| // 0x58000050 |
| // Little endian. |
| stub[0] = 0x50; |
| stub[1] = 0x00; |
| stub[2] = 0x00; |
| stub[3] = 0x58; |
| |
| // Next Instruction: |
| // br x16 |
| // +-------+--+--+-----+------+-----+-----+ |
| // |1101011|00|00|11111|000000|10000|00000| |
| // +-------+--+--+-----+------+-----+-----+ |
| // 0xd61f0200 |
| |
| stub += 4; |
| stub[0] = 0x00; |
| stub[1] = 0x02; |
| stub[2] = 0x1f; |
| stub[3] = 0xd6; |
| |
| // Now the absolute address (64 bits). |
| uint64_t *target = reinterpret_cast<uint64_t*>(stub + 4); |
| *target = reinterpret_cast<uint64_t>(addr); |
| } |
| |
| size_t StubLayoutARM::getUnitStubSize() const { |
| return 8; |
| } |
| |
| void StubLayoutARM::setStubAddress(void *stub_, void *addr) { |
| uint8_t *stub = (uint8_t *)stub_; |
| stub[0] = 0x04; // ldr pc, [pc, #-4] |
| stub[1] = 0xf0; // ldr pc, [pc, #-4] |
| stub[2] = 0x1f; // ldr pc, [pc, #-4] |
| stub[3] = 0xe5; // ldr pc, [pc, #-4] |
| |
| void **target = (void **)(stub + 4); |
| *target = addr; |
| } |
| |
| size_t StubLayoutMIPS::getUnitStubSize() const { |
| return 16; |
| } |
| |
| void StubLayoutMIPS::setStubAddress(void *stub_, void *addr) { |
| uint32_t addr32 = (uint32_t)(uintptr_t)addr; |
| uint16_t addr_hi16 = (addr32 >> 16) & 0xffff; |
| uint16_t addr_lo16 = addr32 & 0xffff; |
| |
| uint32_t *stub = (uint32_t *)stub_; |
| stub[0] = 0x3c190000ul | addr_hi16; // lui |
| stub[1] = 0x37390000ul | addr_lo16; // ori |
| stub[2] = 0x03200008ul; // jr (jump register) |
| stub[3] = 0x00000000ul; // nop |
| } |
| |
| size_t StubLayoutX86::getUnitStubSize() const { |
| return 8; |
| } |
| |
| void StubLayoutX86::setStubAddress(void *stub_, void *addr) { |
| uint8_t *stub = (uint8_t *)stub_; |
| stub[0] = 0xE9; // 32-bit pc-relative jump. |
| void **target = (void **)(stub + 1); |
| *target = addr; |
| } |
| |
| size_t StubLayoutX86_64::getUnitStubSize() const { |
| return 16; |
| } |
| |
| void StubLayoutX86_64::setStubAddress(void *stub_, void *addr) { |
| // x86 doesn't have proper register/mem to store the jump destination |
| // use below instructions to jump to the specified address |
| |
| // jmp *0x0(%rip); jump to the location which is stored in next instruction |
| // addr; this is not a real instruction, just an address |
| uint8_t *stub = (uint8_t*)stub_; |
| stub[0] = 0xff; |
| stub[1] = 0x25; |
| stub[2] = 0x0; |
| stub[3] = 0x0; |
| stub[4] = 0x0; |
| stub[5] = 0x0; |
| uint64_t *target = reinterpret_cast<uint64_t*>(stub + 6); |
| *target = reinterpret_cast<uint64_t>(addr); |
| } |
| |