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 37 static uintptr_t StartAddr = 0x7e000000UL; 38 #endif 39 40 MemChunk::MemChunk() : buf((unsigned char *)MAP_FAILED), buf_size(0) { 41 } 42 43 MemChunk::~MemChunk() { 44 if (buf != MAP_FAILED) { 45 munmap(buf, buf_size); 46 } 47 } 48 49 bool 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 74 void MemChunk::print() const { 75 if (buf != MAP_FAILED) { 76 dump_hex(buf, buf_size, 0, buf_size); 77 } 78 } 79 80 bool 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
