Josh Gao | 682282e | 2017-04-17 18:31:26 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2017 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 "safe_copy.h" |
| 18 | |
Josh Gao | 9a2eea3 | 2017-04-19 15:44:20 -0700 | [diff] [blame] | 19 | #include <errno.h> |
| 20 | #include <string.h> |
Josh Gao | 682282e | 2017-04-17 18:31:26 -0700 | [diff] [blame] | 21 | #include <sys/user.h> |
| 22 | |
David Sehr | 9c4a015 | 2018-04-05 12:23:54 -0700 | [diff] [blame] | 23 | #include "android-base/logging.h" |
David Sehr | 1979c64 | 2018-04-26 14:41:18 -0700 | [diff] [blame] | 24 | #include "globals.h" |
David Sehr | 9c4a015 | 2018-04-05 12:23:54 -0700 | [diff] [blame] | 25 | #include "gtest/gtest.h" |
David Sehr | 10db8fe | 2018-07-18 11:01:20 -0700 | [diff] [blame] | 26 | #include "mman.h" |
David Sehr | 9c4a015 | 2018-04-05 12:23:54 -0700 | [diff] [blame] | 27 | |
Andreas Gampe | 01f7743 | 2017-05-24 09:56:30 -0700 | [diff] [blame] | 28 | |
Josh Gao | 682282e | 2017-04-17 18:31:26 -0700 | [diff] [blame] | 29 | namespace art { |
| 30 | |
| 31 | #if defined(__linux__) |
| 32 | |
| 33 | TEST(SafeCopyTest, smoke) { |
Andreas Gampe | 01f7743 | 2017-05-24 09:56:30 -0700 | [diff] [blame] | 34 | DCHECK_EQ(kPageSize, static_cast<decltype(kPageSize)>(PAGE_SIZE)); |
| 35 | |
Josh Gao | 9a2eea3 | 2017-04-19 15:44:20 -0700 | [diff] [blame] | 36 | // Map four pages, mark the second one as PROT_NONE, unmap the last one. |
Andreas Gampe | 01f7743 | 2017-05-24 09:56:30 -0700 | [diff] [blame] | 37 | void* map = mmap(nullptr, kPageSize * 4, PROT_READ | PROT_WRITE, |
Josh Gao | 682282e | 2017-04-17 18:31:26 -0700 | [diff] [blame] | 38 | MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); |
| 39 | ASSERT_NE(MAP_FAILED, map); |
| 40 | char* page1 = static_cast<char*>(map); |
Andreas Gampe | 01f7743 | 2017-05-24 09:56:30 -0700 | [diff] [blame] | 41 | char* page2 = page1 + kPageSize; |
| 42 | char* page3 = page2 + kPageSize; |
| 43 | char* page4 = page3 + kPageSize; |
| 44 | ASSERT_EQ(0, mprotect(page1 + kPageSize, kPageSize, PROT_NONE)); |
| 45 | ASSERT_EQ(0, munmap(page4, kPageSize)); |
Josh Gao | 682282e | 2017-04-17 18:31:26 -0700 | [diff] [blame] | 46 | |
| 47 | page1[0] = 'a'; |
Andreas Gampe | 01f7743 | 2017-05-24 09:56:30 -0700 | [diff] [blame] | 48 | page1[kPageSize - 1] = 'z'; |
Josh Gao | 682282e | 2017-04-17 18:31:26 -0700 | [diff] [blame] | 49 | |
Josh Gao | 9a2eea3 | 2017-04-19 15:44:20 -0700 | [diff] [blame] | 50 | page3[0] = 'b'; |
Andreas Gampe | 01f7743 | 2017-05-24 09:56:30 -0700 | [diff] [blame] | 51 | page3[kPageSize - 1] = 'y'; |
Josh Gao | 9a2eea3 | 2017-04-19 15:44:20 -0700 | [diff] [blame] | 52 | |
Andreas Gampe | 01f7743 | 2017-05-24 09:56:30 -0700 | [diff] [blame] | 53 | char buf[kPageSize]; |
Josh Gao | 682282e | 2017-04-17 18:31:26 -0700 | [diff] [blame] | 54 | |
| 55 | // Completely valid read. |
| 56 | memset(buf, 0xCC, sizeof(buf)); |
Andreas Gampe | 01f7743 | 2017-05-24 09:56:30 -0700 | [diff] [blame] | 57 | EXPECT_EQ(static_cast<ssize_t>(kPageSize), SafeCopy(buf, page1, kPageSize)) << strerror(errno); |
| 58 | EXPECT_EQ(0, memcmp(buf, page1, kPageSize)); |
Josh Gao | 682282e | 2017-04-17 18:31:26 -0700 | [diff] [blame] | 59 | |
Josh Gao | 9a2eea3 | 2017-04-19 15:44:20 -0700 | [diff] [blame] | 60 | // Reading into a guard page. |
Josh Gao | 682282e | 2017-04-17 18:31:26 -0700 | [diff] [blame] | 61 | memset(buf, 0xCC, sizeof(buf)); |
Andreas Gampe | 01f7743 | 2017-05-24 09:56:30 -0700 | [diff] [blame] | 62 | EXPECT_EQ(static_cast<ssize_t>(kPageSize - 1), SafeCopy(buf, page1 + 1, kPageSize)); |
| 63 | EXPECT_EQ(0, memcmp(buf, page1 + 1, kPageSize - 1)); |
Josh Gao | 682282e | 2017-04-17 18:31:26 -0700 | [diff] [blame] | 64 | |
Josh Gao | 9a2eea3 | 2017-04-19 15:44:20 -0700 | [diff] [blame] | 65 | // Reading from a guard page into a real page. |
| 66 | memset(buf, 0xCC, sizeof(buf)); |
Andreas Gampe | 01f7743 | 2017-05-24 09:56:30 -0700 | [diff] [blame] | 67 | EXPECT_EQ(0, SafeCopy(buf, page2 + kPageSize - 1, kPageSize)); |
Josh Gao | 9a2eea3 | 2017-04-19 15:44:20 -0700 | [diff] [blame] | 68 | |
| 69 | // Reading off of the end of a mapping. |
| 70 | memset(buf, 0xCC, sizeof(buf)); |
Andreas Gampe | 01f7743 | 2017-05-24 09:56:30 -0700 | [diff] [blame] | 71 | EXPECT_EQ(static_cast<ssize_t>(kPageSize), SafeCopy(buf, page3, kPageSize * 2)); |
| 72 | EXPECT_EQ(0, memcmp(buf, page3, kPageSize)); |
Josh Gao | 9a2eea3 | 2017-04-19 15:44:20 -0700 | [diff] [blame] | 73 | |
Josh Gao | 682282e | 2017-04-17 18:31:26 -0700 | [diff] [blame] | 74 | // Completely invalid. |
Andreas Gampe | 01f7743 | 2017-05-24 09:56:30 -0700 | [diff] [blame] | 75 | EXPECT_EQ(0, SafeCopy(buf, page1 + kPageSize, kPageSize)); |
Josh Gao | 9a2eea3 | 2017-04-19 15:44:20 -0700 | [diff] [blame] | 76 | |
| 77 | // Clean up. |
Andreas Gampe | 01f7743 | 2017-05-24 09:56:30 -0700 | [diff] [blame] | 78 | ASSERT_EQ(0, munmap(map, kPageSize * 3)); |
Josh Gao | 9a2eea3 | 2017-04-19 15:44:20 -0700 | [diff] [blame] | 79 | } |
| 80 | |
| 81 | TEST(SafeCopyTest, alignment) { |
Andreas Gampe | 01f7743 | 2017-05-24 09:56:30 -0700 | [diff] [blame] | 82 | DCHECK_EQ(kPageSize, static_cast<decltype(kPageSize)>(PAGE_SIZE)); |
| 83 | |
Josh Gao | 9a2eea3 | 2017-04-19 15:44:20 -0700 | [diff] [blame] | 84 | // Copy the middle of a mapping to the end of another one. |
Andreas Gampe | 01f7743 | 2017-05-24 09:56:30 -0700 | [diff] [blame] | 85 | void* src_map = mmap(nullptr, kPageSize * 3, PROT_READ | PROT_WRITE, |
Josh Gao | 9a2eea3 | 2017-04-19 15:44:20 -0700 | [diff] [blame] | 86 | MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); |
| 87 | ASSERT_NE(MAP_FAILED, src_map); |
| 88 | |
| 89 | // Add a guard page to make sure we don't write past the end of the mapping. |
Andreas Gampe | 01f7743 | 2017-05-24 09:56:30 -0700 | [diff] [blame] | 90 | void* dst_map = mmap(nullptr, kPageSize * 4, PROT_READ | PROT_WRITE, |
Josh Gao | 9a2eea3 | 2017-04-19 15:44:20 -0700 | [diff] [blame] | 91 | MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); |
| 92 | ASSERT_NE(MAP_FAILED, dst_map); |
| 93 | |
| 94 | char* src = static_cast<char*>(src_map); |
| 95 | char* dst = static_cast<char*>(dst_map); |
Andreas Gampe | 01f7743 | 2017-05-24 09:56:30 -0700 | [diff] [blame] | 96 | ASSERT_EQ(0, mprotect(dst + 3 * kPageSize, kPageSize, PROT_NONE)); |
Josh Gao | 9a2eea3 | 2017-04-19 15:44:20 -0700 | [diff] [blame] | 97 | |
| 98 | src[512] = 'a'; |
Andreas Gampe | 01f7743 | 2017-05-24 09:56:30 -0700 | [diff] [blame] | 99 | src[kPageSize * 3 - 512 - 1] = 'z'; |
Josh Gao | 9a2eea3 | 2017-04-19 15:44:20 -0700 | [diff] [blame] | 100 | |
Andreas Gampe | 01f7743 | 2017-05-24 09:56:30 -0700 | [diff] [blame] | 101 | EXPECT_EQ(static_cast<ssize_t>(kPageSize * 3 - 1024), |
| 102 | SafeCopy(dst + 1024, src + 512, kPageSize * 3 - 1024)); |
| 103 | EXPECT_EQ(0, memcmp(dst + 1024, src + 512, kPageSize * 3 - 1024)); |
Josh Gao | 9a2eea3 | 2017-04-19 15:44:20 -0700 | [diff] [blame] | 104 | |
Andreas Gampe | 01f7743 | 2017-05-24 09:56:30 -0700 | [diff] [blame] | 105 | ASSERT_EQ(0, munmap(src_map, kPageSize * 3)); |
| 106 | ASSERT_EQ(0, munmap(dst_map, kPageSize * 4)); |
Josh Gao | 682282e | 2017-04-17 18:31:26 -0700 | [diff] [blame] | 107 | } |
| 108 | |
| 109 | #endif // defined(__linux__) |
| 110 | |
| 111 | } // namespace art |