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 "MemChunk.h" 18 19#include "utils/flush_cpu_cache.h" 20#include "utils/helper.h" 21 22#include <llvm/Support/raw_ostream.h> 23 24#include <sys/mman.h> 25 26#include <stdlib.h> 27 28#ifndef MAP_32BIT 29#define MAP_32BIT 0 30// Note: If the <sys/mman.h> does not come with MAP_32BIT, then we 31// define it as zero, so that it won't manipulate the flags. 32#endif 33 34//#define USE_FIXED_ADDR_MEM_CHUNK 1 35 36#if USE_FIXED_ADDR_MEM_CHUNK 37static uintptr_t StartAddr = 0x7e000000UL; 38#endif 39 40MemChunk::MemChunk() : buf((unsigned char *)MAP_FAILED), buf_size(0) { 41} 42 43MemChunk::~MemChunk() { 44 if (buf != MAP_FAILED) { 45 munmap(buf, buf_size); 46 } 47} 48 49bool MemChunk::allocate(size_t size) { 50#if USE_FIXED_ADDR_MEM_CHUNK 51 buf = (unsigned char *)mmap((void *)StartAddr, size, 52 PROT_READ | PROT_WRITE, 53 MAP_PRIVATE | MAP_ANON | MAP_32BIT, 54 -1, 0); 55#else 56 buf = (unsigned char *)mmap(0, size, 57 PROT_READ | PROT_WRITE, 58 MAP_PRIVATE | MAP_ANON | MAP_32BIT, 59 -1, 0); 60#endif 61 62 if (buf == MAP_FAILED) { 63 return false; 64 } 65 66#if USE_FIXED_ADDR_MEM_CHUNK 67 StartAddr += (size + 4095) / 4096 * 4096; 68#endif 69 70 buf_size = size; 71 return true; 72} 73 74void MemChunk::print() const { 75 if (buf != MAP_FAILED) { 76 dump_hex(buf, buf_size, 0, buf_size); 77 } 78} 79 80bool MemChunk::protect(int prot) { 81 if (buf_size > 0) { 82 int ret = mprotect((void *)buf, buf_size, prot); 83 if (ret == -1) { 84 llvm::errs() << "Error: Can't mprotect.\n"; 85 return false; 86 } 87 88 if (prot & PROT_EXEC) { 89 FLUSH_CPU_CACHE(buf, buf + buf_size); 90 } 91 } 92 93 return true; 94} 95