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1 /*
2  * Copyright (C) 2017 The Android Open Source Project
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  *  * Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  *  * Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in
12  *    the documentation and/or other materials provided with the
13  *    distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
16  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
17  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
18  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
19  * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
21  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
22  * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
23  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
24  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
25  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 #include <gtest/gtest.h>
30 
31 #include <link.h>
32 
TEST(link,dl_iterate_phdr_early_exit)33 TEST(link, dl_iterate_phdr_early_exit) {
34   static size_t call_count = 0;
35   ASSERT_EQ(123, dl_iterate_phdr([](dl_phdr_info*, size_t, void*) { ++call_count; return 123; },
36                                  nullptr));
37   ASSERT_EQ(1u, call_count);
38 }
39 
TEST(link,dl_iterate_phdr)40 TEST(link, dl_iterate_phdr) {
41   struct Functor {
42     static int Callback(dl_phdr_info* i, size_t s, void* data) {
43       reinterpret_cast<Functor*>(data)->DoChecks(i, s);
44       return 0;
45     }
46     void DoChecks(dl_phdr_info* info, size_t s) {
47       ASSERT_EQ(sizeof(dl_phdr_info), s);
48 
49       ASSERT_TRUE(info->dlpi_name != nullptr);
50 
51       // Find the first PT_LOAD program header so we can find the ELF header.
52       for (ElfW(Half) i = 0; i < info->dlpi_phnum; ++i) {
53         const ElfW(Phdr)* phdr = reinterpret_cast<const ElfW(Phdr)*>(&info->dlpi_phdr[i]);
54         if (phdr->p_type == PT_LOAD) {
55           const ElfW(Ehdr)* ehdr = reinterpret_cast<const ElfW(Ehdr)*>(info->dlpi_addr +
56                                                                        phdr->p_vaddr);
57           // Does it look like an ELF file?
58           ASSERT_EQ(0, memcmp(ehdr, ELFMAG, SELFMAG));
59           // Does the e_phnum match what dl_iterate_phdr told us?
60           ASSERT_EQ(info->dlpi_phnum, ehdr->e_phnum);
61           break;
62         }
63       }
64     }
65     size_t count;
66   } f = {};
67   ASSERT_EQ(0, dl_iterate_phdr(Functor::Callback, &f));
68 }
69 
70 #if __arm__
read_exidx_func(uintptr_t * entry)71 static uintptr_t read_exidx_func(uintptr_t* entry) {
72   int32_t offset = *entry;
73   // Sign-extend from int31 to int32.
74   if ((offset & 0x40000000) != 0) {
75     offset += -0x7fffffff - 1;
76   }
77   return reinterpret_cast<uintptr_t>(entry) + offset;
78 }
another_function_in_same_ELF_file()79 __attribute__((__unused__)) static void another_function_in_same_ELF_file() {}
80 #endif
81 
TEST(link,dl_unwind_find_exidx)82 TEST(link, dl_unwind_find_exidx) {
83 #if __arm__
84   int count = 0;
85   struct eit_entry_t {
86     uintptr_t one;
87     uintptr_t two;
88   };
89   eit_entry_t* entries = reinterpret_cast<eit_entry_t*>(dl_unwind_find_exidx(
90       reinterpret_cast<_Unwind_Ptr>(read_exidx_func), &count));
91   ASSERT_TRUE(entries != nullptr);
92   ASSERT_GT(count, 0);
93 
94   // Sanity checks
95   uintptr_t func = reinterpret_cast<uintptr_t>(read_exidx_func);
96   bool found = false;
97   for (int i = 0; i < count; ++i) {
98     // Entries must have bit 31 clear.
99     ASSERT_TRUE((entries[i].one & (1<<31)) == 0);
100 
101     uintptr_t exidx_func = read_exidx_func(&entries[i].one);
102 
103     // If our function is compiled for thumb, exception table contains our address - 1.
104     if (func == exidx_func || func == exidx_func + 1) found = true;
105 
106     // Entries must be sorted. Some addresses may appear twice if function
107     // is compiled for arm.
108     if (i > 0) {
109       EXPECT_GE(exidx_func, read_exidx_func(&entries[i - 1].one)) << i;
110     }
111   }
112   ASSERT_TRUE(found);
113 #else
114   GTEST_LOG_(INFO) << "dl_unwind_find_exidx is an ARM-only API\n";
115 #endif
116 }
117