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 AllocFunc MemChunk::VendorAlloc = NULL;
45 FreeFunc MemChunk::VendorFree = NULL;
46
MemChunk()47 MemChunk::MemChunk() : buf(NULL), buf_size(0), bVendorBuf(true) {
48 }
49
~MemChunk()50 MemChunk::~MemChunk() {
51 if (!invalidBuf() && bVendorBuf && VendorFree) {
52 (*VendorFree)(buf);
53 return;
54 }
55 if (!invalidBuf()) {
56 munmap(buf, buf_size);
57 }
58 }
59
invalidBuf() const60 bool MemChunk::invalidBuf() const {
61 return (buf == 0 || buf == (unsigned char *)MAP_FAILED);
62 }
63
allocate(size_t size)64 bool 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
print() const98 void MemChunk::print() const {
99 if (!invalidBuf()) {
100 dump_hex(buf, buf_size, 0, buf_size);
101 }
102 }
103
protect(int prot)104 bool 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