1 // SPDX-License-Identifier: GPL-2.0
2 #include <test_progs.h>
3 #include <sys/mman.h>
4 #include "test_mmap.skel.h"
5
6 struct map_data {
7 __u64 val[512 * 4];
8 };
9
roundup_page(size_t sz)10 static size_t roundup_page(size_t sz)
11 {
12 long page_size = sysconf(_SC_PAGE_SIZE);
13 return (sz + page_size - 1) / page_size * page_size;
14 }
15
test_mmap(void)16 void test_mmap(void)
17 {
18 const size_t bss_sz = roundup_page(sizeof(struct test_mmap__bss));
19 const size_t map_sz = roundup_page(sizeof(struct map_data));
20 const int zero = 0, one = 1, two = 2, far = 1500;
21 const long page_size = sysconf(_SC_PAGE_SIZE);
22 int err, duration = 0, i, data_map_fd, data_map_id, tmp_fd, rdmap_fd;
23 struct bpf_map *data_map, *bss_map;
24 void *bss_mmaped = NULL, *map_mmaped = NULL, *tmp0, *tmp1, *tmp2;
25 struct test_mmap__bss *bss_data;
26 struct bpf_map_info map_info;
27 __u32 map_info_sz = sizeof(map_info);
28 struct map_data *map_data;
29 struct test_mmap *skel;
30 __u64 val = 0;
31
32 skel = test_mmap__open();
33 if (CHECK(!skel, "skel_open", "skeleton open failed\n"))
34 return;
35
36 err = bpf_map__set_max_entries(skel->maps.rdonly_map, page_size);
37 if (CHECK(err != 0, "bpf_map__set_max_entries", "bpf_map__set_max_entries failed\n"))
38 goto cleanup;
39
40 /* at least 4 pages of data */
41 err = bpf_map__set_max_entries(skel->maps.data_map,
42 4 * (page_size / sizeof(u64)));
43 if (CHECK(err != 0, "bpf_map__set_max_entries", "bpf_map__set_max_entries failed\n"))
44 goto cleanup;
45
46 err = test_mmap__load(skel);
47 if (CHECK(err != 0, "skel_load", "skeleton load failed\n"))
48 goto cleanup;
49
50 bss_map = skel->maps.bss;
51 data_map = skel->maps.data_map;
52 data_map_fd = bpf_map__fd(data_map);
53
54 rdmap_fd = bpf_map__fd(skel->maps.rdonly_map);
55 tmp1 = mmap(NULL, page_size, PROT_READ | PROT_WRITE, MAP_SHARED, rdmap_fd, 0);
56 if (CHECK(tmp1 != MAP_FAILED, "rdonly_write_mmap", "unexpected success\n")) {
57 munmap(tmp1, page_size);
58 goto cleanup;
59 }
60 /* now double-check if it's mmap()'able at all */
61 tmp1 = mmap(NULL, page_size, PROT_READ, MAP_SHARED, rdmap_fd, 0);
62 if (CHECK(tmp1 == MAP_FAILED, "rdonly_read_mmap", "failed: %d\n", errno))
63 goto cleanup;
64
65 /* get map's ID */
66 memset(&map_info, 0, map_info_sz);
67 err = bpf_map_get_info_by_fd(data_map_fd, &map_info, &map_info_sz);
68 if (CHECK(err, "map_get_info", "failed %d\n", errno))
69 goto cleanup;
70 data_map_id = map_info.id;
71
72 /* mmap BSS map */
73 bss_mmaped = mmap(NULL, bss_sz, PROT_READ | PROT_WRITE, MAP_SHARED,
74 bpf_map__fd(bss_map), 0);
75 if (CHECK(bss_mmaped == MAP_FAILED, "bss_mmap",
76 ".bss mmap failed: %d\n", errno)) {
77 bss_mmaped = NULL;
78 goto cleanup;
79 }
80 /* map as R/W first */
81 map_mmaped = mmap(NULL, map_sz, PROT_READ | PROT_WRITE, MAP_SHARED,
82 data_map_fd, 0);
83 if (CHECK(map_mmaped == MAP_FAILED, "data_mmap",
84 "data_map mmap failed: %d\n", errno)) {
85 map_mmaped = NULL;
86 goto cleanup;
87 }
88
89 bss_data = bss_mmaped;
90 map_data = map_mmaped;
91
92 CHECK_FAIL(bss_data->in_val);
93 CHECK_FAIL(bss_data->out_val);
94 CHECK_FAIL(skel->bss->in_val);
95 CHECK_FAIL(skel->bss->out_val);
96 CHECK_FAIL(map_data->val[0]);
97 CHECK_FAIL(map_data->val[1]);
98 CHECK_FAIL(map_data->val[2]);
99 CHECK_FAIL(map_data->val[far]);
100
101 err = test_mmap__attach(skel);
102 if (CHECK(err, "attach_raw_tp", "err %d\n", err))
103 goto cleanup;
104
105 bss_data->in_val = 123;
106 val = 111;
107 CHECK_FAIL(bpf_map_update_elem(data_map_fd, &zero, &val, 0));
108
109 usleep(1);
110
111 CHECK_FAIL(bss_data->in_val != 123);
112 CHECK_FAIL(bss_data->out_val != 123);
113 CHECK_FAIL(skel->bss->in_val != 123);
114 CHECK_FAIL(skel->bss->out_val != 123);
115 CHECK_FAIL(map_data->val[0] != 111);
116 CHECK_FAIL(map_data->val[1] != 222);
117 CHECK_FAIL(map_data->val[2] != 123);
118 CHECK_FAIL(map_data->val[far] != 3 * 123);
119
120 CHECK_FAIL(bpf_map_lookup_elem(data_map_fd, &zero, &val));
121 CHECK_FAIL(val != 111);
122 CHECK_FAIL(bpf_map_lookup_elem(data_map_fd, &one, &val));
123 CHECK_FAIL(val != 222);
124 CHECK_FAIL(bpf_map_lookup_elem(data_map_fd, &two, &val));
125 CHECK_FAIL(val != 123);
126 CHECK_FAIL(bpf_map_lookup_elem(data_map_fd, &far, &val));
127 CHECK_FAIL(val != 3 * 123);
128
129 /* data_map freeze should fail due to R/W mmap() */
130 err = bpf_map_freeze(data_map_fd);
131 if (CHECK(!err || errno != EBUSY, "no_freeze",
132 "data_map freeze succeeded: err=%d, errno=%d\n", err, errno))
133 goto cleanup;
134
135 err = mprotect(map_mmaped, map_sz, PROT_READ);
136 if (CHECK(err, "mprotect_ro", "mprotect to r/o failed %d\n", errno))
137 goto cleanup;
138
139 /* unmap R/W mapping */
140 err = munmap(map_mmaped, map_sz);
141 map_mmaped = NULL;
142 if (CHECK(err, "data_map_munmap", "data_map munmap failed: %d\n", errno))
143 goto cleanup;
144
145 /* re-map as R/O now */
146 map_mmaped = mmap(NULL, map_sz, PROT_READ, MAP_SHARED, data_map_fd, 0);
147 if (CHECK(map_mmaped == MAP_FAILED, "data_mmap",
148 "data_map R/O mmap failed: %d\n", errno)) {
149 map_mmaped = NULL;
150 goto cleanup;
151 }
152 err = mprotect(map_mmaped, map_sz, PROT_WRITE);
153 if (CHECK(!err, "mprotect_wr", "mprotect() succeeded unexpectedly!\n"))
154 goto cleanup;
155 err = mprotect(map_mmaped, map_sz, PROT_EXEC);
156 if (CHECK(!err, "mprotect_ex", "mprotect() succeeded unexpectedly!\n"))
157 goto cleanup;
158 map_data = map_mmaped;
159
160 /* map/unmap in a loop to test ref counting */
161 for (i = 0; i < 10; i++) {
162 int flags = i % 2 ? PROT_READ : PROT_WRITE;
163 void *p;
164
165 p = mmap(NULL, map_sz, flags, MAP_SHARED, data_map_fd, 0);
166 if (CHECK_FAIL(p == MAP_FAILED))
167 goto cleanup;
168 err = munmap(p, map_sz);
169 if (CHECK_FAIL(err))
170 goto cleanup;
171 }
172
173 /* data_map freeze should now succeed due to no R/W mapping */
174 err = bpf_map_freeze(data_map_fd);
175 if (CHECK(err, "freeze", "data_map freeze failed: err=%d, errno=%d\n",
176 err, errno))
177 goto cleanup;
178
179 /* mapping as R/W now should fail */
180 tmp1 = mmap(NULL, map_sz, PROT_READ | PROT_WRITE, MAP_SHARED,
181 data_map_fd, 0);
182 if (CHECK(tmp1 != MAP_FAILED, "data_mmap", "mmap succeeded\n")) {
183 munmap(tmp1, map_sz);
184 goto cleanup;
185 }
186
187 bss_data->in_val = 321;
188 usleep(1);
189 CHECK_FAIL(bss_data->in_val != 321);
190 CHECK_FAIL(bss_data->out_val != 321);
191 CHECK_FAIL(skel->bss->in_val != 321);
192 CHECK_FAIL(skel->bss->out_val != 321);
193 CHECK_FAIL(map_data->val[0] != 111);
194 CHECK_FAIL(map_data->val[1] != 222);
195 CHECK_FAIL(map_data->val[2] != 321);
196 CHECK_FAIL(map_data->val[far] != 3 * 321);
197
198 /* check some more advanced mmap() manipulations */
199
200 tmp0 = mmap(NULL, 4 * page_size, PROT_READ, MAP_SHARED | MAP_ANONYMOUS,
201 -1, 0);
202 if (CHECK(tmp0 == MAP_FAILED, "adv_mmap0", "errno %d\n", errno))
203 goto cleanup;
204
205 /* map all but last page: pages 1-3 mapped */
206 tmp1 = mmap(tmp0, 3 * page_size, PROT_READ, MAP_SHARED | MAP_FIXED,
207 data_map_fd, 0);
208 if (CHECK(tmp0 != tmp1, "adv_mmap1", "tmp0: %p, tmp1: %p\n", tmp0, tmp1)) {
209 munmap(tmp0, 4 * page_size);
210 goto cleanup;
211 }
212
213 /* unmap second page: pages 1, 3 mapped */
214 err = munmap(tmp1 + page_size, page_size);
215 if (CHECK(err, "adv_mmap2", "errno %d\n", errno)) {
216 munmap(tmp1, 4 * page_size);
217 goto cleanup;
218 }
219
220 /* map page 2 back */
221 tmp2 = mmap(tmp1 + page_size, page_size, PROT_READ,
222 MAP_SHARED | MAP_FIXED, data_map_fd, 0);
223 if (CHECK(tmp2 == MAP_FAILED, "adv_mmap3", "errno %d\n", errno)) {
224 munmap(tmp1, page_size);
225 munmap(tmp1 + 2*page_size, 2 * page_size);
226 goto cleanup;
227 }
228 CHECK(tmp1 + page_size != tmp2, "adv_mmap4",
229 "tmp1: %p, tmp2: %p\n", tmp1, tmp2);
230
231 /* re-map all 4 pages */
232 tmp2 = mmap(tmp1, 4 * page_size, PROT_READ, MAP_SHARED | MAP_FIXED,
233 data_map_fd, 0);
234 if (CHECK(tmp2 == MAP_FAILED, "adv_mmap5", "errno %d\n", errno)) {
235 munmap(tmp1, 4 * page_size); /* unmap page 1 */
236 goto cleanup;
237 }
238 CHECK(tmp1 != tmp2, "adv_mmap6", "tmp1: %p, tmp2: %p\n", tmp1, tmp2);
239
240 map_data = tmp2;
241 CHECK_FAIL(bss_data->in_val != 321);
242 CHECK_FAIL(bss_data->out_val != 321);
243 CHECK_FAIL(skel->bss->in_val != 321);
244 CHECK_FAIL(skel->bss->out_val != 321);
245 CHECK_FAIL(map_data->val[0] != 111);
246 CHECK_FAIL(map_data->val[1] != 222);
247 CHECK_FAIL(map_data->val[2] != 321);
248 CHECK_FAIL(map_data->val[far] != 3 * 321);
249
250 munmap(tmp2, 4 * page_size);
251
252 /* map all 4 pages, but with pg_off=1 page, should fail */
253 tmp1 = mmap(NULL, 4 * page_size, PROT_READ, MAP_SHARED | MAP_FIXED,
254 data_map_fd, page_size /* initial page shift */);
255 if (CHECK(tmp1 != MAP_FAILED, "adv_mmap7", "unexpected success")) {
256 munmap(tmp1, 4 * page_size);
257 goto cleanup;
258 }
259
260 tmp1 = mmap(NULL, map_sz, PROT_READ, MAP_SHARED, data_map_fd, 0);
261 if (CHECK(tmp1 == MAP_FAILED, "last_mmap", "failed %d\n", errno))
262 goto cleanup;
263
264 test_mmap__destroy(skel);
265 skel = NULL;
266 CHECK_FAIL(munmap(bss_mmaped, bss_sz));
267 bss_mmaped = NULL;
268 CHECK_FAIL(munmap(map_mmaped, map_sz));
269 map_mmaped = NULL;
270
271 /* map should be still held by active mmap */
272 tmp_fd = bpf_map_get_fd_by_id(data_map_id);
273 if (CHECK(tmp_fd < 0, "get_map_by_id", "failed %d\n", errno)) {
274 munmap(tmp1, map_sz);
275 goto cleanup;
276 }
277 close(tmp_fd);
278
279 /* this should release data map finally */
280 munmap(tmp1, map_sz);
281
282 /* we need to wait for RCU grace period */
283 for (i = 0; i < 10000; i++) {
284 __u32 id = data_map_id - 1;
285 if (bpf_map_get_next_id(id, &id) || id > data_map_id)
286 break;
287 usleep(1);
288 }
289
290 /* should fail to get map FD by non-existing ID */
291 tmp_fd = bpf_map_get_fd_by_id(data_map_id);
292 if (CHECK(tmp_fd >= 0, "get_map_by_id_after",
293 "unexpectedly succeeded %d\n", tmp_fd)) {
294 close(tmp_fd);
295 goto cleanup;
296 }
297
298 cleanup:
299 if (bss_mmaped)
300 CHECK_FAIL(munmap(bss_mmaped, bss_sz));
301 if (map_mmaped)
302 CHECK_FAIL(munmap(map_mmaped, map_sz));
303 test_mmap__destroy(skel);
304 }
305