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 BPF_EMBED_OBJ(test_mmap, "test_mmap.o"); 17 18 void test_mmap(void) 19 { 20 const size_t bss_sz = roundup_page(sizeof(struct test_mmap__bss)); 21 const size_t map_sz = roundup_page(sizeof(struct map_data)); 22 const int zero = 0, one = 1, two = 2, far = 1500; 23 const long page_size = sysconf(_SC_PAGE_SIZE); 24 int err, duration = 0, i, data_map_fd; 25 struct bpf_map *data_map, *bss_map; 26 void *bss_mmaped = NULL, *map_mmaped = NULL, *tmp1, *tmp2; 27 struct test_mmap__bss *bss_data; 28 struct map_data *map_data; 29 struct test_mmap *skel; 30 __u64 val = 0; 31 32 33 skel = test_mmap__open_and_load(&test_mmap_embed); 34 if (CHECK(!skel, "skel_open_and_load", "skeleton open/load failed\n")) 35 return; 36 37 bss_map = skel->maps.bss; 38 data_map = skel->maps.data_map; 39 data_map_fd = bpf_map__fd(data_map); 40 41 bss_mmaped = mmap(NULL, bss_sz, PROT_READ | PROT_WRITE, MAP_SHARED, 42 bpf_map__fd(bss_map), 0); 43 if (CHECK(bss_mmaped == MAP_FAILED, "bss_mmap", 44 ".bss mmap failed: %d\n", errno)) { 45 bss_mmaped = NULL; 46 goto cleanup; 47 } 48 /* map as R/W first */ 49 map_mmaped = mmap(NULL, map_sz, PROT_READ | PROT_WRITE, MAP_SHARED, 50 data_map_fd, 0); 51 if (CHECK(map_mmaped == MAP_FAILED, "data_mmap", 52 "data_map mmap failed: %d\n", errno)) { 53 map_mmaped = NULL; 54 goto cleanup; 55 } 56 57 bss_data = bss_mmaped; 58 map_data = map_mmaped; 59 60 CHECK_FAIL(bss_data->in_val); 61 CHECK_FAIL(bss_data->out_val); 62 CHECK_FAIL(skel->bss->in_val); 63 CHECK_FAIL(skel->bss->out_val); 64 CHECK_FAIL(map_data->val[0]); 65 CHECK_FAIL(map_data->val[1]); 66 CHECK_FAIL(map_data->val[2]); 67 CHECK_FAIL(map_data->val[far]); 68 69 err = test_mmap__attach(skel); 70 if (CHECK(err, "attach_raw_tp", "err %d\n", err)) 71 goto cleanup; 72 73 bss_data->in_val = 123; 74 val = 111; 75 CHECK_FAIL(bpf_map_update_elem(data_map_fd, &zero, &val, 0)); 76 77 usleep(1); 78 79 CHECK_FAIL(bss_data->in_val != 123); 80 CHECK_FAIL(bss_data->out_val != 123); 81 CHECK_FAIL(skel->bss->in_val != 123); 82 CHECK_FAIL(skel->bss->out_val != 123); 83 CHECK_FAIL(map_data->val[0] != 111); 84 CHECK_FAIL(map_data->val[1] != 222); 85 CHECK_FAIL(map_data->val[2] != 123); 86 CHECK_FAIL(map_data->val[far] != 3 * 123); 87 88 CHECK_FAIL(bpf_map_lookup_elem(data_map_fd, &zero, &val)); 89 CHECK_FAIL(val != 111); 90 CHECK_FAIL(bpf_map_lookup_elem(data_map_fd, &one, &val)); 91 CHECK_FAIL(val != 222); 92 CHECK_FAIL(bpf_map_lookup_elem(data_map_fd, &two, &val)); 93 CHECK_FAIL(val != 123); 94 CHECK_FAIL(bpf_map_lookup_elem(data_map_fd, &far, &val)); 95 CHECK_FAIL(val != 3 * 123); 96 97 /* data_map freeze should fail due to R/W mmap() */ 98 err = bpf_map_freeze(data_map_fd); 99 if (CHECK(!err || errno != EBUSY, "no_freeze", 100 "data_map freeze succeeded: err=%d, errno=%d\n", err, errno)) 101 goto cleanup; 102 103 /* unmap R/W mapping */ 104 err = munmap(map_mmaped, map_sz); 105 map_mmaped = NULL; 106 if (CHECK(err, "data_map_munmap", "data_map munmap failed: %d\n", errno)) 107 goto cleanup; 108 109 /* re-map as R/O now */ 110 map_mmaped = mmap(NULL, map_sz, PROT_READ, MAP_SHARED, data_map_fd, 0); 111 if (CHECK(map_mmaped == MAP_FAILED, "data_mmap", 112 "data_map R/O mmap failed: %d\n", errno)) { 113 map_mmaped = NULL; 114 goto cleanup; 115 } 116 map_data = map_mmaped; 117 118 /* map/unmap in a loop to test ref counting */ 119 for (i = 0; i < 10; i++) { 120 int flags = i % 2 ? PROT_READ : PROT_WRITE; 121 void *p; 122 123 p = mmap(NULL, map_sz, flags, MAP_SHARED, data_map_fd, 0); 124 if (CHECK_FAIL(p == MAP_FAILED)) 125 goto cleanup; 126 err = munmap(p, map_sz); 127 if (CHECK_FAIL(err)) 128 goto cleanup; 129 } 130 131 /* data_map freeze should now succeed due to no R/W mapping */ 132 err = bpf_map_freeze(data_map_fd); 133 if (CHECK(err, "freeze", "data_map freeze failed: err=%d, errno=%d\n", 134 err, errno)) 135 goto cleanup; 136 137 /* mapping as R/W now should fail */ 138 tmp1 = mmap(NULL, map_sz, PROT_READ | PROT_WRITE, MAP_SHARED, 139 data_map_fd, 0); 140 if (CHECK(tmp1 != MAP_FAILED, "data_mmap", "mmap succeeded\n")) { 141 munmap(tmp1, map_sz); 142 goto cleanup; 143 } 144 145 bss_data->in_val = 321; 146 usleep(1); 147 CHECK_FAIL(bss_data->in_val != 321); 148 CHECK_FAIL(bss_data->out_val != 321); 149 CHECK_FAIL(skel->bss->in_val != 321); 150 CHECK_FAIL(skel->bss->out_val != 321); 151 CHECK_FAIL(map_data->val[0] != 111); 152 CHECK_FAIL(map_data->val[1] != 222); 153 CHECK_FAIL(map_data->val[2] != 321); 154 CHECK_FAIL(map_data->val[far] != 3 * 321); 155 156 /* check some more advanced mmap() manipulations */ 157 158 /* map all but last page: pages 1-3 mapped */ 159 tmp1 = mmap(NULL, 3 * page_size, PROT_READ, MAP_SHARED, 160 data_map_fd, 0); 161 if (CHECK(tmp1 == MAP_FAILED, "adv_mmap1", "errno %d\n", errno)) 162 goto cleanup; 163 164 /* unmap second page: pages 1, 3 mapped */ 165 err = munmap(tmp1 + page_size, page_size); 166 if (CHECK(err, "adv_mmap2", "errno %d\n", errno)) { 167 munmap(tmp1, map_sz); 168 goto cleanup; 169 } 170 171 /* map page 2 back */ 172 tmp2 = mmap(tmp1 + page_size, page_size, PROT_READ, 173 MAP_SHARED | MAP_FIXED, data_map_fd, 0); 174 if (CHECK(tmp2 == MAP_FAILED, "adv_mmap3", "errno %d\n", errno)) { 175 munmap(tmp1, page_size); 176 munmap(tmp1 + 2*page_size, page_size); 177 goto cleanup; 178 } 179 CHECK(tmp1 + page_size != tmp2, "adv_mmap4", 180 "tmp1: %p, tmp2: %p\n", tmp1, tmp2); 181 182 /* re-map all 4 pages */ 183 tmp2 = mmap(tmp1, 4 * page_size, PROT_READ, MAP_SHARED | MAP_FIXED, 184 data_map_fd, 0); 185 if (CHECK(tmp2 == MAP_FAILED, "adv_mmap5", "errno %d\n", errno)) { 186 munmap(tmp1, 3 * page_size); /* unmap page 1 */ 187 goto cleanup; 188 } 189 CHECK(tmp1 != tmp2, "adv_mmap6", "tmp1: %p, tmp2: %p\n", tmp1, tmp2); 190 191 map_data = tmp2; 192 CHECK_FAIL(bss_data->in_val != 321); 193 CHECK_FAIL(bss_data->out_val != 321); 194 CHECK_FAIL(skel->bss->in_val != 321); 195 CHECK_FAIL(skel->bss->out_val != 321); 196 CHECK_FAIL(map_data->val[0] != 111); 197 CHECK_FAIL(map_data->val[1] != 222); 198 CHECK_FAIL(map_data->val[2] != 321); 199 CHECK_FAIL(map_data->val[far] != 3 * 321); 200 201 munmap(tmp2, 4 * page_size); 202 cleanup: 203 if (bss_mmaped) 204 CHECK_FAIL(munmap(bss_mmaped, bss_sz)); 205 if (map_mmaped) 206 CHECK_FAIL(munmap(map_mmaped, map_sz)); 207 test_mmap__destroy(skel); 208 } 209