1 /*
2  * Copyright (C) 2013 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 <stdlib.h>
18 #include <string.h>
19 #include <sys/mman.h>
20 
21 #include <gtest/gtest.h>
22 
23 #include "../linker_block_allocator.h"
24 
25 #include <unistd.h>
26 
27 namespace {
28 
29 struct test_struct_nominal {
30   void* pointer;
31   ssize_t value;
32 };
33 
34 /*
35  * this one has size below allocator cap which is 2*sizeof(void*)
36  */
37 struct test_struct_small {
38   char dummy_str[5];
39 };
40 
41 /*
42  * 1009 byte struct (1009 is prime)
43  */
44 struct test_struct_larger {
45   char dummy_str[1009];
46 };
47 
48 static size_t kPageSize = sysconf(_SC_PAGE_SIZE);
49 };
50 
TEST(linker_allocator,test_nominal)51 TEST(linker_allocator, test_nominal) {
52   LinkerTypeAllocator<test_struct_nominal> allocator;
53 
54   test_struct_nominal* ptr1 = allocator.alloc();
55   ASSERT_TRUE(ptr1 != nullptr);
56   ASSERT_EQ(0U, reinterpret_cast<uintptr_t>(ptr1) % 16);
57   test_struct_nominal* ptr2 = allocator.alloc();
58   ASSERT_EQ(0U, reinterpret_cast<uintptr_t>(ptr2) % 16);
59   ASSERT_TRUE(ptr2 != nullptr);
60   // they should be next to each other.
61   ASSERT_EQ(reinterpret_cast<uint8_t*>(ptr1)+16, reinterpret_cast<uint8_t*>(ptr2));
62 
63   ptr1->value = 42;
64 
65   allocator.free(ptr1);
66   allocator.free(ptr2);
67 }
68 
TEST(linker_allocator,test_small)69 TEST(linker_allocator, test_small) {
70   LinkerTypeAllocator<test_struct_small> allocator;
71 
72   char* ptr1 = reinterpret_cast<char*>(allocator.alloc());
73   char* ptr2 = reinterpret_cast<char*>(allocator.alloc());
74 
75   ASSERT_TRUE(ptr1 != nullptr);
76   ASSERT_EQ(0U, reinterpret_cast<uintptr_t>(ptr1) % 16);
77   ASSERT_TRUE(ptr2 != nullptr);
78   ASSERT_EQ(0U, reinterpret_cast<uintptr_t>(ptr2) % 16);
79   ASSERT_EQ(ptr1+16, ptr2); // aligned to 16
80 }
81 
TEST(linker_allocator,test_larger)82 TEST(linker_allocator, test_larger) {
83   LinkerTypeAllocator<test_struct_larger> allocator;
84 
85   test_struct_larger* ptr1 = allocator.alloc();
86   test_struct_larger* ptr2 = allocator.alloc();
87 
88   ASSERT_TRUE(ptr1 != nullptr);
89   ASSERT_EQ(0U, reinterpret_cast<uintptr_t>(ptr1) % 16);
90   ASSERT_TRUE(ptr2 != nullptr);
91   ASSERT_EQ(0U, reinterpret_cast<uintptr_t>(ptr2) % 16);
92 
93   ASSERT_EQ(reinterpret_cast<uint8_t*>(ptr1) + 1024, reinterpret_cast<uint8_t*>(ptr2));
94 
95   // lets allocate until we reach next page.
96   size_t n = kPageSize/sizeof(test_struct_larger) + 1 - 2;
97 
98   for (size_t i=0; i<n; ++i) {
99     ASSERT_TRUE(allocator.alloc() != nullptr);
100   }
101 
102   test_struct_larger* ptr_to_free = allocator.alloc();
103   ASSERT_TRUE(ptr_to_free != nullptr);
104   allocator.free(ptr1);
105 }
106 
protect_all()107 static void protect_all() {
108   LinkerTypeAllocator<test_struct_larger> allocator;
109 
110   // number of allocs to reach the end of first page
111   size_t n = kPageSize/sizeof(test_struct_larger) - 1;
112   test_struct_larger* page1_ptr = allocator.alloc();
113 
114   for (size_t i=0; i<n; ++i) {
115     allocator.alloc();
116   }
117 
118   test_struct_larger* page2_ptr = allocator.alloc();
119   allocator.protect_all(PROT_READ);
120   allocator.protect_all(PROT_READ | PROT_WRITE);
121   // check access
122   page2_ptr->dummy_str[23] = 27;
123   page1_ptr->dummy_str[13] = 11;
124 
125   allocator.protect_all(PROT_READ);
126   fprintf(stderr, "trying to access protected page");
127 
128   // this should result in segmentation fault
129   page1_ptr->dummy_str[11] = 7;
130 }
131 
TEST(linker_allocator,test_protect)132 TEST(linker_allocator, test_protect) {
133   testing::FLAGS_gtest_death_test_style = "threadsafe";
134   ASSERT_EXIT(protect_all(), testing::KilledBySignal(SIGSEGV), "trying to access protected page");
135 }
136 
137