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 #ifndef USE_MINGW /* TODO create a proper HAVE_MMAN_H */ 25 #include <sys/mman.h> 26 #else 27 #include "mmanWindows.h" 28 #endif 29 30 #include <stdlib.h> 31 32 #ifndef MAP_32BIT 33 #define MAP_32BIT 0 34 // Note: If the <sys/mman.h> does not come with MAP_32BIT, then we 35 // define it as zero, so that it won't manipulate the flags. 36 #endif 37 38 //#define USE_FIXED_ADDR_MEM_CHUNK 1 39 40 #if USE_FIXED_ADDR_MEM_CHUNK 41 static uintptr_t StartAddr = 0x7e000000UL; 42 #endif 43 44 MemChunk::MemChunk() : buf((unsigned char *)MAP_FAILED), buf_size(0) { 45 } 46 47 MemChunk::~MemChunk() { 48 if (buf != MAP_FAILED) { 49 munmap(buf, buf_size); 50 } 51 } 52 53 bool MemChunk::allocate(size_t size) { 54 if (size == 0) { 55 return true; 56 } 57 #if USE_FIXED_ADDR_MEM_CHUNK 58 buf = (unsigned char *)mmap((void *)StartAddr, size, 59 PROT_READ | PROT_WRITE, 60 MAP_PRIVATE | MAP_ANON | MAP_32BIT, 61 -1, 0); 62 #else 63 buf = (unsigned char *)mmap(0, size, 64 PROT_READ | PROT_WRITE, 65 MAP_PRIVATE | MAP_ANON | MAP_32BIT, 66 -1, 0); 67 #endif 68 69 if (buf == MAP_FAILED) { 70 return false; 71 } 72 73 #if USE_FIXED_ADDR_MEM_CHUNK 74 StartAddr += (size + 4095) / 4096 * 4096; 75 #endif 76 77 buf_size = size; 78 return true; 79 } 80 81 void MemChunk::print() const { 82 if (buf != MAP_FAILED) { 83 dump_hex(buf, buf_size, 0, buf_size); 84 } 85 } 86 87 bool MemChunk::protect(int prot) { 88 if (buf_size > 0) { 89 int ret = mprotect((void *)buf, buf_size, prot); 90 if (ret == -1) { 91 llvm::errs() << "Error: Can't mprotect.\n"; 92 return false; 93 } 94 95 if (prot & PROT_EXEC) { 96 FLUSH_CPU_CACHE(buf, buf + buf_size); 97 } 98 } 99 100 return true; 101 } 102