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
41static uintptr_t StartAddr = 0x7e000000UL;
42#endif
43
44AllocFunc MemChunk::VendorAlloc = NULL;
45FreeFunc MemChunk::VendorFree = NULL;
46
47MemChunk::MemChunk() : buf(NULL), buf_size(0), bVendorBuf(true) {
48}
49
50MemChunk::~MemChunk() {
51  if (!invalidBuf() && bVendorBuf && VendorFree) {
52    (*VendorFree)(buf);
53    return;
54  }
55  if (!invalidBuf()) {
56    munmap(buf, buf_size);
57  }
58}
59
60bool MemChunk::invalidBuf() const {
61  return (buf == 0 || buf == (unsigned char *)MAP_FAILED);
62}
63
64bool MemChunk::allocate(size_t size) {
65  if (size == 0) {
66    return true;
67  }
68  if (VendorAlloc) {
69    buf = (unsigned char*)(*VendorAlloc)(size, 0);
70  }
71  if (invalidBuf()) {
72    bVendorBuf = false;
73#if USE_FIXED_ADDR_MEM_CHUNK
74    buf = (unsigned char *)mmap((void *)StartAddr, size,
75                                PROT_READ | PROT_WRITE,
76                                MAP_PRIVATE | MAP_ANON | MAP_32BIT,
77                                -1, 0);
78#else
79    buf = (unsigned char *)mmap(0, size,
80                                PROT_READ | PROT_WRITE,
81                                MAP_PRIVATE | MAP_ANON | MAP_32BIT,
82                                -1, 0);
83#endif
84  }
85
86  if (invalidBuf()) {
87    return false;
88  }
89
90#if USE_FIXED_ADDR_MEM_CHUNK
91  StartAddr += (size + 4095) / 4096 * 4096;
92#endif
93
94  buf_size = size;
95  return true;
96}
97
98void MemChunk::print() const {
99  if (!invalidBuf()) {
100    dump_hex(buf, buf_size, 0, buf_size);
101  }
102}
103
104bool MemChunk::protect(int prot) {
105  if (buf_size > 0) {
106    int ret = mprotect((void *)buf, buf_size, prot);
107    if (ret == -1) {
108      llvm::errs() << "Error: Can't mprotect.\n";
109      return false;
110    }
111
112    if (prot & PROT_EXEC) {
113      FLUSH_CPU_CACHE(buf, buf + buf_size);
114    }
115  }
116
117  return true;
118}
119