1 | // SPDX-License-Identifier: GPL-2.0 |
2 | |
3 | /* |
4 | * Test that MAP_FIXED_NOREPLACE works. |
5 | * |
6 | * Copyright 2018, Jann Horn <jannh@google.com> |
7 | * Copyright 2018, Michael Ellerman, IBM Corporation. |
8 | */ |
9 | |
10 | #include <sys/mman.h> |
11 | #include <errno.h> |
12 | #include <stdio.h> |
13 | #include <stdlib.h> |
14 | #include <unistd.h> |
15 | #include "../kselftest.h" |
16 | |
17 | static void dump_maps(void) |
18 | { |
19 | char cmd[32]; |
20 | |
21 | snprintf(cmd, sizeof(cmd), "cat /proc/%d/maps" , getpid()); |
22 | system(cmd); |
23 | } |
24 | |
25 | static unsigned long find_base_addr(unsigned long size) |
26 | { |
27 | void *addr; |
28 | unsigned long flags; |
29 | |
30 | flags = MAP_PRIVATE | MAP_ANONYMOUS; |
31 | addr = mmap(NULL, size, PROT_NONE, flags, -1, 0); |
32 | if (addr == MAP_FAILED) |
33 | ksft_exit_fail_msg(msg: "Error: couldn't map the space we need for the test\n" ); |
34 | |
35 | if (munmap(addr, size) != 0) |
36 | ksft_exit_fail_msg(msg: "Error: munmap failed\n" ); |
37 | |
38 | return (unsigned long)addr; |
39 | } |
40 | |
41 | int main(void) |
42 | { |
43 | unsigned long base_addr; |
44 | unsigned long flags, addr, size, page_size; |
45 | char *p; |
46 | |
47 | ksft_print_header(); |
48 | ksft_set_plan(plan: 9); |
49 | |
50 | page_size = sysconf(_SC_PAGE_SIZE); |
51 | |
52 | /* let's find a base addr that is free before we start the tests */ |
53 | size = 5 * page_size; |
54 | base_addr = find_base_addr(size); |
55 | |
56 | flags = MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED_NOREPLACE; |
57 | |
58 | /* Check we can map all the areas we need below */ |
59 | addr = base_addr; |
60 | size = 5 * page_size; |
61 | p = mmap((void *)addr, size, PROT_NONE, flags, -1, 0); |
62 | if (p == MAP_FAILED) { |
63 | dump_maps(); |
64 | ksft_exit_fail_msg(msg: "Error: couldn't map the space we need for the test\n" ); |
65 | } |
66 | if (munmap((void *)addr, 5 * page_size) != 0) { |
67 | dump_maps(); |
68 | ksft_exit_fail_msg(msg: "Error: munmap failed!?\n" ); |
69 | } |
70 | ksft_test_result_pass(msg: "mmap() @ 0x%lx-0x%lx p=%p result=%m\n" , addr, addr + size, p); |
71 | |
72 | addr = base_addr + page_size; |
73 | size = 3 * page_size; |
74 | p = mmap((void *)addr, size, PROT_NONE, flags, -1, 0); |
75 | if (p == MAP_FAILED) { |
76 | dump_maps(); |
77 | ksft_exit_fail_msg(msg: "Error: first mmap() failed unexpectedly\n" ); |
78 | } |
79 | ksft_test_result_pass(msg: "mmap() @ 0x%lx-0x%lx p=%p result=%m\n" , addr, addr + size, p); |
80 | |
81 | /* |
82 | * Exact same mapping again: |
83 | * base | free | new |
84 | * +1 | mapped | new |
85 | * +2 | mapped | new |
86 | * +3 | mapped | new |
87 | * +4 | free | new |
88 | */ |
89 | addr = base_addr; |
90 | size = 5 * page_size; |
91 | p = mmap((void *)addr, size, PROT_NONE, flags, -1, 0); |
92 | if (p != MAP_FAILED) { |
93 | dump_maps(); |
94 | ksft_exit_fail_msg(msg: "Error:1: mmap() succeeded when it shouldn't have\n" ); |
95 | } |
96 | ksft_test_result_pass(msg: "mmap() @ 0x%lx-0x%lx p=%p result=%m\n" , addr, addr + size, p); |
97 | |
98 | /* |
99 | * Second mapping contained within first: |
100 | * |
101 | * base | free | |
102 | * +1 | mapped | |
103 | * +2 | mapped | new |
104 | * +3 | mapped | |
105 | * +4 | free | |
106 | */ |
107 | addr = base_addr + (2 * page_size); |
108 | size = page_size; |
109 | p = mmap((void *)addr, size, PROT_NONE, flags, -1, 0); |
110 | if (p != MAP_FAILED) { |
111 | dump_maps(); |
112 | ksft_exit_fail_msg(msg: "Error:2: mmap() succeeded when it shouldn't have\n" ); |
113 | } |
114 | ksft_test_result_pass(msg: "mmap() @ 0x%lx-0x%lx p=%p result=%m\n" , addr, addr + size, p); |
115 | |
116 | /* |
117 | * Overlap end of existing mapping: |
118 | * base | free | |
119 | * +1 | mapped | |
120 | * +2 | mapped | |
121 | * +3 | mapped | new |
122 | * +4 | free | new |
123 | */ |
124 | addr = base_addr + (3 * page_size); |
125 | size = 2 * page_size; |
126 | p = mmap((void *)addr, size, PROT_NONE, flags, -1, 0); |
127 | if (p != MAP_FAILED) { |
128 | dump_maps(); |
129 | ksft_exit_fail_msg(msg: "Error:3: mmap() succeeded when it shouldn't have\n" ); |
130 | } |
131 | ksft_test_result_pass(msg: "mmap() @ 0x%lx-0x%lx p=%p result=%m\n" , addr, addr + size, p); |
132 | |
133 | /* |
134 | * Overlap start of existing mapping: |
135 | * base | free | new |
136 | * +1 | mapped | new |
137 | * +2 | mapped | |
138 | * +3 | mapped | |
139 | * +4 | free | |
140 | */ |
141 | addr = base_addr; |
142 | size = 2 * page_size; |
143 | p = mmap((void *)addr, size, PROT_NONE, flags, -1, 0); |
144 | if (p != MAP_FAILED) { |
145 | dump_maps(); |
146 | ksft_exit_fail_msg(msg: "Error:4: mmap() succeeded when it shouldn't have\n" ); |
147 | } |
148 | ksft_test_result_pass(msg: "mmap() @ 0x%lx-0x%lx p=%p result=%m\n" , addr, addr + size, p); |
149 | |
150 | /* |
151 | * Adjacent to start of existing mapping: |
152 | * base | free | new |
153 | * +1 | mapped | |
154 | * +2 | mapped | |
155 | * +3 | mapped | |
156 | * +4 | free | |
157 | */ |
158 | addr = base_addr; |
159 | size = page_size; |
160 | p = mmap((void *)addr, size, PROT_NONE, flags, -1, 0); |
161 | if (p == MAP_FAILED) { |
162 | dump_maps(); |
163 | ksft_exit_fail_msg(msg: "Error:5: mmap() failed when it shouldn't have\n" ); |
164 | } |
165 | ksft_test_result_pass(msg: "mmap() @ 0x%lx-0x%lx p=%p result=%m\n" , addr, addr + size, p); |
166 | |
167 | /* |
168 | * Adjacent to end of existing mapping: |
169 | * base | free | |
170 | * +1 | mapped | |
171 | * +2 | mapped | |
172 | * +3 | mapped | |
173 | * +4 | free | new |
174 | */ |
175 | addr = base_addr + (4 * page_size); |
176 | size = page_size; |
177 | p = mmap((void *)addr, size, PROT_NONE, flags, -1, 0); |
178 | if (p == MAP_FAILED) { |
179 | dump_maps(); |
180 | ksft_exit_fail_msg(msg: "Error:6: mmap() failed when it shouldn't have\n" ); |
181 | } |
182 | ksft_test_result_pass(msg: "mmap() @ 0x%lx-0x%lx p=%p result=%m\n" , addr, addr + size, p); |
183 | |
184 | addr = base_addr; |
185 | size = 5 * page_size; |
186 | if (munmap((void *)addr, size) != 0) { |
187 | dump_maps(); |
188 | ksft_exit_fail_msg(msg: "Error: munmap failed!?\n" ); |
189 | } |
190 | ksft_test_result_pass(msg: "Base Address unmap() successful\n" ); |
191 | |
192 | ksft_finished(); |
193 | } |
194 | |