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 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 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; 23 struct bpf_map *data_map, *bss_map; 24 void *bss_mmaped = NULL, *map_mmaped = NULL, *tmp1, *tmp2; 25 struct test_mmap__bss *bss_data; 26 struct map_data *map_data; 27 struct test_mmap *skel; 28 __u64 val = 0; 29 30 31 skel = test_mmap__open_and_load(); 32 if (CHECK(!skel, "skel_open_and_load", "skeleton open/load failed\n")) 33 return; 34 35 bss_map = skel->maps.bss; 36 data_map = skel->maps.data_map; 37 data_map_fd = bpf_map__fd(data_map); 38 39 bss_mmaped = mmap(NULL, bss_sz, PROT_READ | PROT_WRITE, MAP_SHARED, 40 bpf_map__fd(bss_map), 0); 41 if (CHECK(bss_mmaped == MAP_FAILED, "bss_mmap", 42 ".bss mmap failed: %d\n", errno)) { 43 bss_mmaped = NULL; 44 goto cleanup; 45 } 46 /* map as R/W first */ 47 map_mmaped = mmap(NULL, map_sz, PROT_READ | PROT_WRITE, MAP_SHARED, 48 data_map_fd, 0); 49 if (CHECK(map_mmaped == MAP_FAILED, "data_mmap", 50 "data_map mmap failed: %d\n", errno)) { 51 map_mmaped = NULL; 52 goto cleanup; 53 } 54 55 bss_data = bss_mmaped; 56 map_data = map_mmaped; 57 58 CHECK_FAIL(bss_data->in_val); 59 CHECK_FAIL(bss_data->out_val); 60 CHECK_FAIL(skel->bss->in_val); 61 CHECK_FAIL(skel->bss->out_val); 62 CHECK_FAIL(map_data->val[0]); 63 CHECK_FAIL(map_data->val[1]); 64 CHECK_FAIL(map_data->val[2]); 65 CHECK_FAIL(map_data->val[far]); 66 67 err = test_mmap__attach(skel); 68 if (CHECK(err, "attach_raw_tp", "err %d\n", err)) 69 goto cleanup; 70 71 bss_data->in_val = 123; 72 val = 111; 73 CHECK_FAIL(bpf_map_update_elem(data_map_fd, &zero, &val, 0)); 74 75 usleep(1); 76 77 CHECK_FAIL(bss_data->in_val != 123); 78 CHECK_FAIL(bss_data->out_val != 123); 79 CHECK_FAIL(skel->bss->in_val != 123); 80 CHECK_FAIL(skel->bss->out_val != 123); 81 CHECK_FAIL(map_data->val[0] != 111); 82 CHECK_FAIL(map_data->val[1] != 222); 83 CHECK_FAIL(map_data->val[2] != 123); 84 CHECK_FAIL(map_data->val[far] != 3 * 123); 85 86 CHECK_FAIL(bpf_map_lookup_elem(data_map_fd, &zero, &val)); 87 CHECK_FAIL(val != 111); 88 CHECK_FAIL(bpf_map_lookup_elem(data_map_fd, &one, &val)); 89 CHECK_FAIL(val != 222); 90 CHECK_FAIL(bpf_map_lookup_elem(data_map_fd, &two, &val)); 91 CHECK_FAIL(val != 123); 92 CHECK_FAIL(bpf_map_lookup_elem(data_map_fd, &far, &val)); 93 CHECK_FAIL(val != 3 * 123); 94 95 /* data_map freeze should fail due to R/W mmap() */ 96 err = bpf_map_freeze(data_map_fd); 97 if (CHECK(!err || errno != EBUSY, "no_freeze", 98 "data_map freeze succeeded: err=%d, errno=%d\n", err, errno)) 99 goto cleanup; 100 101 /* unmap R/W mapping */ 102 err = munmap(map_mmaped, map_sz); 103 map_mmaped = NULL; 104 if (CHECK(err, "data_map_munmap", "data_map munmap failed: %d\n", errno)) 105 goto cleanup; 106 107 /* re-map as R/O now */ 108 map_mmaped = mmap(NULL, map_sz, PROT_READ, MAP_SHARED, data_map_fd, 0); 109 if (CHECK(map_mmaped == MAP_FAILED, "data_mmap", 110 "data_map R/O mmap failed: %d\n", errno)) { 111 map_mmaped = NULL; 112 goto cleanup; 113 } 114 map_data = map_mmaped; 115 116 /* map/unmap in a loop to test ref counting */ 117 for (i = 0; i < 10; i++) { 118 int flags = i % 2 ? PROT_READ : PROT_WRITE; 119 void *p; 120 121 p = mmap(NULL, map_sz, flags, MAP_SHARED, data_map_fd, 0); 122 if (CHECK_FAIL(p == MAP_FAILED)) 123 goto cleanup; 124 err = munmap(p, map_sz); 125 if (CHECK_FAIL(err)) 126 goto cleanup; 127 } 128 129 /* data_map freeze should now succeed due to no R/W mapping */ 130 err = bpf_map_freeze(data_map_fd); 131 if (CHECK(err, "freeze", "data_map freeze failed: err=%d, errno=%d\n", 132 err, errno)) 133 goto cleanup; 134 135 /* mapping as R/W now should fail */ 136 tmp1 = mmap(NULL, map_sz, PROT_READ | PROT_WRITE, MAP_SHARED, 137 data_map_fd, 0); 138 if (CHECK(tmp1 != MAP_FAILED, "data_mmap", "mmap succeeded\n")) { 139 munmap(tmp1, map_sz); 140 goto cleanup; 141 } 142 143 bss_data->in_val = 321; 144 usleep(1); 145 CHECK_FAIL(bss_data->in_val != 321); 146 CHECK_FAIL(bss_data->out_val != 321); 147 CHECK_FAIL(skel->bss->in_val != 321); 148 CHECK_FAIL(skel->bss->out_val != 321); 149 CHECK_FAIL(map_data->val[0] != 111); 150 CHECK_FAIL(map_data->val[1] != 222); 151 CHECK_FAIL(map_data->val[2] != 321); 152 CHECK_FAIL(map_data->val[far] != 3 * 321); 153 154 /* check some more advanced mmap() manipulations */ 155 156 /* map all but last page: pages 1-3 mapped */ 157 tmp1 = mmap(NULL, 3 * page_size, PROT_READ, MAP_SHARED, 158 data_map_fd, 0); 159 if (CHECK(tmp1 == MAP_FAILED, "adv_mmap1", "errno %d\n", errno)) 160 goto cleanup; 161 162 /* unmap second page: pages 1, 3 mapped */ 163 err = munmap(tmp1 + page_size, page_size); 164 if (CHECK(err, "adv_mmap2", "errno %d\n", errno)) { 165 munmap(tmp1, map_sz); 166 goto cleanup; 167 } 168 169 /* map page 2 back */ 170 tmp2 = mmap(tmp1 + page_size, page_size, PROT_READ, 171 MAP_SHARED | MAP_FIXED, data_map_fd, 0); 172 if (CHECK(tmp2 == MAP_FAILED, "adv_mmap3", "errno %d\n", errno)) { 173 munmap(tmp1, page_size); 174 munmap(tmp1 + 2*page_size, page_size); 175 goto cleanup; 176 } 177 CHECK(tmp1 + page_size != tmp2, "adv_mmap4", 178 "tmp1: %p, tmp2: %p\n", tmp1, tmp2); 179 180 /* re-map all 4 pages */ 181 tmp2 = mmap(tmp1, 4 * page_size, PROT_READ, MAP_SHARED | MAP_FIXED, 182 data_map_fd, 0); 183 if (CHECK(tmp2 == MAP_FAILED, "adv_mmap5", "errno %d\n", errno)) { 184 munmap(tmp1, 3 * page_size); /* unmap page 1 */ 185 goto cleanup; 186 } 187 CHECK(tmp1 != tmp2, "adv_mmap6", "tmp1: %p, tmp2: %p\n", tmp1, tmp2); 188 189 map_data = tmp2; 190 CHECK_FAIL(bss_data->in_val != 321); 191 CHECK_FAIL(bss_data->out_val != 321); 192 CHECK_FAIL(skel->bss->in_val != 321); 193 CHECK_FAIL(skel->bss->out_val != 321); 194 CHECK_FAIL(map_data->val[0] != 111); 195 CHECK_FAIL(map_data->val[1] != 222); 196 CHECK_FAIL(map_data->val[2] != 321); 197 CHECK_FAIL(map_data->val[far] != 3 * 321); 198 199 munmap(tmp2, 4 * page_size); 200 cleanup: 201 if (bss_mmaped) 202 CHECK_FAIL(munmap(bss_mmaped, bss_sz)); 203 if (map_mmaped) 204 CHECK_FAIL(munmap(map_mmaped, map_sz)); 205 test_mmap__destroy(skel); 206 } 207