1 /* 2 * Copyright 2011, 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 "StubLayout.h" 18 19 #include "utils/flush_cpu_cache.h" 20 #include "utils/raw_ostream.h" 21 #include "utils/rsl_assert.h" 22 23 #include <stdint.h> 24 #include <stdlib.h> 25 #include <sys/mman.h> 26 27 StubLayout::StubLayout() : table(NULL), count(0) { 28 } 29 30 void StubLayout::initStubTable(unsigned char *table_, size_t count_) { 31 table = table_; 32 count = count_; 33 } 34 35 void *StubLayout::allocateStub(void *addr) { 36 // Check if we have created this stub or not. 37 std::map<void *, void *>::iterator index_iter = stub_index.find(addr); 38 39 if (index_iter != stub_index.end()) { 40 return index_iter->second; 41 } 42 43 // We have to create a new stub 44 if (count == 0) { 45 // No free stub slot is available 46 return NULL; 47 } 48 49 // Initialize the stub 50 unsigned char *stub = table; 51 setStubAddress(stub, addr); 52 stub_index.insert(std::make_pair(addr, stub)); 53 54 // Increase the free stub slot pointer 55 table += getUnitStubSize(); 56 count--; 57 58 return stub; 59 } 60 61 size_t StubLayout::calcStubTableSize(size_t count) const { 62 return count * getUnitStubSize(); 63 } 64 65 size_t StubLayoutARM::getUnitStubSize() const { 66 return 8; 67 } 68 69 void StubLayoutARM::setStubAddress(void *stub_, void *addr) { 70 uint8_t *stub = (uint8_t *)stub_; 71 stub[0] = 0x04; // ldr pc, [pc, #-4] 72 stub[1] = 0xf0; // ldr pc, [pc, #-4] 73 stub[2] = 0x1f; // ldr pc, [pc, #-4] 74 stub[3] = 0xe5; // ldr pc, [pc, #-4] 75 76 void **target = (void **)(stub + 4); 77 *target = addr; 78 } 79 80 size_t StubLayoutMIPS::getUnitStubSize() const { 81 return 16; 82 } 83 84 void StubLayoutMIPS::setStubAddress(void *stub_, void *addr) { 85 uint32_t addr32 = (uint32_t)(uintptr_t)addr; 86 uint16_t addr_hi16 = (addr32 >> 16) & 0xffff; 87 uint16_t addr_lo16 = addr32 & 0xffff; 88 89 uint32_t *stub = (uint32_t *)stub_; 90 stub[0] = 0x3c190000ul | addr_hi16; // lui 91 stub[1] = 0x37390000ul | addr_lo16; // ori 92 stub[2] = 0x03200008ul; // jr (jump register) 93 stub[3] = 0x00000000ul; // nop 94 } 95
