1 /*
2 * Copyright (C) 2015 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 "berberis/runtime_primitives/exec_region_anonymous.h"
18
19 #include <sys/mman.h>
20
21 #include "berberis/base/fd.h"
22 #include "berberis/base/mmap.h"
23
24 namespace berberis {
25
Create(size_t size)26 ExecRegion ExecRegionAnonymousFactory::Create(size_t size) {
27 size = AlignUpPageSize(size);
28
29 auto fd = CreateMemfdOrDie("exec");
30 FtruncateOrDie(fd, static_cast<off64_t>(size));
31
32 #if defined(__x86_64__)
33 constexpr int kBerberisFlags = kMmapBerberis32Bit;
34 #else
35 // TODO(b/363611588): enable for other backends (arm64/riscv64)
36 constexpr int kBerberisFlags = 0;
37 #endif // defined(__x86_64__)
38
39 ExecRegion result{
40 static_cast<uint8_t*>(MmapImplOrDie({.size = size,
41 .prot = PROT_READ | PROT_EXEC,
42 .flags = MAP_SHARED,
43 .fd = fd,
44 .berberis_flags = kBerberisFlags})),
45 static_cast<uint8_t*>(MmapImplOrDie(
46 {.size = size, .prot = PROT_READ | PROT_WRITE, .flags = MAP_SHARED, .fd = fd})),
47 size};
48
49 CloseUnsafe(fd);
50 return result;
51 }
52
53 } // namespace berberis
54