Simon Guo | 26b4224 | 2016-10-07 16:59:52 -0700 | [diff] [blame] | 1 | /* |
| 2 | * It tests the mlock/mlock2() when they are invoked |
| 3 | * on randomly memory region. |
| 4 | */ |
| 5 | #include <unistd.h> |
| 6 | #include <sys/resource.h> |
| 7 | #include <sys/capability.h> |
| 8 | #include <sys/mman.h> |
| 9 | #include <fcntl.h> |
| 10 | #include <string.h> |
| 11 | #include <sys/ipc.h> |
| 12 | #include <sys/shm.h> |
| 13 | #include <time.h> |
| 14 | #include "mlock2.h" |
| 15 | |
| 16 | #define CHUNK_UNIT (128 * 1024) |
| 17 | #define MLOCK_RLIMIT_SIZE (CHUNK_UNIT * 2) |
| 18 | #define MLOCK_WITHIN_LIMIT_SIZE CHUNK_UNIT |
| 19 | #define MLOCK_OUTOF_LIMIT_SIZE (CHUNK_UNIT * 3) |
| 20 | |
| 21 | #define TEST_LOOP 100 |
| 22 | #define PAGE_ALIGN(size, ps) (((size) + ((ps) - 1)) & ~((ps) - 1)) |
| 23 | |
| 24 | int set_cap_limits(rlim_t max) |
| 25 | { |
| 26 | struct rlimit new; |
| 27 | cap_t cap = cap_init(); |
| 28 | |
| 29 | new.rlim_cur = max; |
| 30 | new.rlim_max = max; |
| 31 | if (setrlimit(RLIMIT_MEMLOCK, &new)) { |
| 32 | perror("setrlimit() returns error\n"); |
| 33 | return -1; |
| 34 | } |
| 35 | |
| 36 | /* drop capabilities including CAP_IPC_LOCK */ |
| 37 | if (cap_set_proc(cap)) { |
| 38 | perror("cap_set_proc() returns error\n"); |
| 39 | return -2; |
| 40 | } |
| 41 | |
| 42 | return 0; |
| 43 | } |
| 44 | |
| 45 | int get_proc_locked_vm_size(void) |
| 46 | { |
| 47 | FILE *f; |
| 48 | int ret = -1; |
| 49 | char line[1024] = {0}; |
| 50 | unsigned long lock_size = 0; |
| 51 | |
| 52 | f = fopen("/proc/self/status", "r"); |
| 53 | if (!f) { |
| 54 | perror("fopen"); |
| 55 | return -1; |
| 56 | } |
| 57 | |
| 58 | while (fgets(line, 1024, f)) { |
| 59 | if (strstr(line, "VmLck")) { |
| 60 | ret = sscanf(line, "VmLck:\t%8lu kB", &lock_size); |
| 61 | if (ret <= 0) { |
| 62 | printf("sscanf() on VmLck error: %s: %d\n", |
| 63 | line, ret); |
| 64 | fclose(f); |
| 65 | return -1; |
| 66 | } |
| 67 | fclose(f); |
| 68 | return (int)(lock_size << 10); |
| 69 | } |
| 70 | } |
| 71 | |
| 72 | perror("cann't parse VmLck in /proc/self/status\n"); |
| 73 | fclose(f); |
| 74 | return -1; |
| 75 | } |
| 76 | |
| 77 | /* |
| 78 | * Get the MMUPageSize of the memory region including input |
| 79 | * address from proc file. |
| 80 | * |
| 81 | * return value: on error case, 0 will be returned. |
| 82 | * Otherwise the page size(in bytes) is returned. |
| 83 | */ |
| 84 | int get_proc_page_size(unsigned long addr) |
| 85 | { |
| 86 | FILE *smaps; |
| 87 | char *line; |
| 88 | unsigned long mmupage_size = 0; |
| 89 | size_t size; |
| 90 | |
| 91 | smaps = seek_to_smaps_entry(addr); |
| 92 | if (!smaps) { |
| 93 | printf("Unable to parse /proc/self/smaps\n"); |
| 94 | return 0; |
| 95 | } |
| 96 | |
| 97 | while (getline(&line, &size, smaps) > 0) { |
| 98 | if (!strstr(line, "MMUPageSize")) { |
| 99 | free(line); |
| 100 | line = NULL; |
| 101 | size = 0; |
| 102 | continue; |
| 103 | } |
| 104 | |
| 105 | /* found the MMUPageSize of this section */ |
| 106 | if (sscanf(line, "MMUPageSize: %8lu kB", |
| 107 | &mmupage_size) < 1) { |
| 108 | printf("Unable to parse smaps entry for Size:%s\n", |
| 109 | line); |
| 110 | break; |
| 111 | } |
| 112 | |
| 113 | } |
| 114 | free(line); |
| 115 | if (smaps) |
| 116 | fclose(smaps); |
| 117 | return mmupage_size << 10; |
| 118 | } |
| 119 | |
| 120 | /* |
| 121 | * Test mlock/mlock2() on provided memory chunk. |
| 122 | * It expects the mlock/mlock2() to be successful (within rlimit) |
| 123 | * |
| 124 | * With allocated memory chunk [p, p + alloc_size), this |
| 125 | * test will choose start/len randomly to perform mlock/mlock2 |
| 126 | * [start, start + len] memory range. The range is within range |
| 127 | * of the allocated chunk. |
| 128 | * |
| 129 | * The memory region size alloc_size is within the rlimit. |
| 130 | * So we always expect a success of mlock/mlock2. |
| 131 | * |
| 132 | * VmLck is assumed to be 0 before this test. |
| 133 | * |
| 134 | * return value: 0 - success |
| 135 | * else: failure |
| 136 | */ |
| 137 | int test_mlock_within_limit(char *p, int alloc_size) |
| 138 | { |
| 139 | int i; |
| 140 | int ret = 0; |
| 141 | int locked_vm_size = 0; |
| 142 | struct rlimit cur; |
| 143 | int page_size = 0; |
| 144 | |
| 145 | getrlimit(RLIMIT_MEMLOCK, &cur); |
| 146 | if (cur.rlim_cur < alloc_size) { |
| 147 | printf("alloc_size[%d] < %u rlimit,lead to mlock failure\n", |
| 148 | alloc_size, (unsigned int)cur.rlim_cur); |
| 149 | return -1; |
| 150 | } |
| 151 | |
| 152 | srand(time(NULL)); |
| 153 | for (i = 0; i < TEST_LOOP; i++) { |
| 154 | /* |
| 155 | * - choose mlock/mlock2 randomly |
| 156 | * - choose lock_size randomly but lock_size < alloc_size |
| 157 | * - choose start_offset randomly but p+start_offset+lock_size |
| 158 | * < p+alloc_size |
| 159 | */ |
| 160 | int is_mlock = !!(rand() % 2); |
| 161 | int lock_size = rand() % alloc_size; |
| 162 | int start_offset = rand() % (alloc_size - lock_size); |
| 163 | |
| 164 | if (is_mlock) |
| 165 | ret = mlock(p + start_offset, lock_size); |
| 166 | else |
| 167 | ret = mlock2_(p + start_offset, lock_size, |
| 168 | MLOCK_ONFAULT); |
| 169 | |
| 170 | if (ret) { |
| 171 | printf("%s() failure at |%p(%d)| mlock:|%p(%d)|\n", |
| 172 | is_mlock ? "mlock" : "mlock2", |
| 173 | p, alloc_size, |
| 174 | p + start_offset, lock_size); |
| 175 | return ret; |
| 176 | } |
| 177 | } |
| 178 | |
| 179 | /* |
| 180 | * Check VmLck left by the tests. |
| 181 | */ |
| 182 | locked_vm_size = get_proc_locked_vm_size(); |
| 183 | page_size = get_proc_page_size((unsigned long)p); |
| 184 | if (page_size == 0) { |
| 185 | printf("cannot get proc MMUPageSize\n"); |
| 186 | return -1; |
| 187 | } |
| 188 | |
| 189 | if (locked_vm_size > PAGE_ALIGN(alloc_size, page_size) + page_size) { |
| 190 | printf("test_mlock_within_limit() left VmLck:%d on %d chunk\n", |
| 191 | locked_vm_size, alloc_size); |
| 192 | return -1; |
| 193 | } |
| 194 | |
| 195 | return 0; |
| 196 | } |
| 197 | |
| 198 | |
| 199 | /* |
| 200 | * We expect the mlock/mlock2() to be fail (outof limitation) |
| 201 | * |
| 202 | * With allocated memory chunk [p, p + alloc_size), this |
| 203 | * test will randomly choose start/len and perform mlock/mlock2 |
| 204 | * on [start, start+len] range. |
| 205 | * |
| 206 | * The memory region size alloc_size is above the rlimit. |
| 207 | * And the len to be locked is higher than rlimit. |
| 208 | * So we always expect a failure of mlock/mlock2. |
| 209 | * No locked page number should be increased as a side effect. |
| 210 | * |
| 211 | * return value: 0 - success |
| 212 | * else: failure |
| 213 | */ |
| 214 | int test_mlock_outof_limit(char *p, int alloc_size) |
| 215 | { |
| 216 | int i; |
| 217 | int ret = 0; |
| 218 | int locked_vm_size = 0, old_locked_vm_size = 0; |
| 219 | struct rlimit cur; |
| 220 | |
| 221 | getrlimit(RLIMIT_MEMLOCK, &cur); |
| 222 | if (cur.rlim_cur >= alloc_size) { |
| 223 | printf("alloc_size[%d] >%u rlimit, violates test condition\n", |
| 224 | alloc_size, (unsigned int)cur.rlim_cur); |
| 225 | return -1; |
| 226 | } |
| 227 | |
| 228 | old_locked_vm_size = get_proc_locked_vm_size(); |
| 229 | srand(time(NULL)); |
| 230 | for (i = 0; i < TEST_LOOP; i++) { |
| 231 | int is_mlock = !!(rand() % 2); |
| 232 | int lock_size = (rand() % (alloc_size - cur.rlim_cur)) |
| 233 | + cur.rlim_cur; |
| 234 | int start_offset = rand() % (alloc_size - lock_size); |
| 235 | |
| 236 | if (is_mlock) |
| 237 | ret = mlock(p + start_offset, lock_size); |
| 238 | else |
| 239 | ret = mlock2_(p + start_offset, lock_size, |
| 240 | MLOCK_ONFAULT); |
| 241 | if (ret == 0) { |
| 242 | printf("%s() succeeds? on %p(%d) mlock%p(%d)\n", |
| 243 | is_mlock ? "mlock" : "mlock2", |
| 244 | p, alloc_size, |
| 245 | p + start_offset, lock_size); |
| 246 | return -1; |
| 247 | } |
| 248 | } |
| 249 | |
| 250 | locked_vm_size = get_proc_locked_vm_size(); |
| 251 | if (locked_vm_size != old_locked_vm_size) { |
| 252 | printf("tests leads to new mlocked page: old[%d], new[%d]\n", |
| 253 | old_locked_vm_size, |
| 254 | locked_vm_size); |
| 255 | return -1; |
| 256 | } |
| 257 | |
| 258 | return 0; |
| 259 | } |
| 260 | |
| 261 | int main(int argc, char **argv) |
| 262 | { |
| 263 | char *p = NULL; |
| 264 | int ret = 0; |
| 265 | |
| 266 | if (set_cap_limits(MLOCK_RLIMIT_SIZE)) |
| 267 | return -1; |
| 268 | |
| 269 | p = malloc(MLOCK_WITHIN_LIMIT_SIZE); |
| 270 | if (p == NULL) { |
| 271 | perror("malloc() failure\n"); |
| 272 | return -1; |
| 273 | } |
| 274 | ret = test_mlock_within_limit(p, MLOCK_WITHIN_LIMIT_SIZE); |
| 275 | if (ret) |
| 276 | return ret; |
| 277 | munlock(p, MLOCK_WITHIN_LIMIT_SIZE); |
| 278 | free(p); |
| 279 | |
| 280 | |
| 281 | p = malloc(MLOCK_OUTOF_LIMIT_SIZE); |
| 282 | if (p == NULL) { |
| 283 | perror("malloc() failure\n"); |
| 284 | return -1; |
| 285 | } |
| 286 | ret = test_mlock_outof_limit(p, MLOCK_OUTOF_LIMIT_SIZE); |
| 287 | if (ret) |
| 288 | return ret; |
| 289 | munlock(p, MLOCK_OUTOF_LIMIT_SIZE); |
| 290 | free(p); |
| 291 | |
| 292 | return 0; |
| 293 | } |