Roman Gushchin | 84092dbc | 2018-05-11 19:03:49 +0100 | [diff] [blame] | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
| 2 | |
| 3 | #define _GNU_SOURCE |
| 4 | |
| 5 | #include <errno.h> |
| 6 | #include <fcntl.h> |
| 7 | #include <linux/limits.h> |
| 8 | #include <signal.h> |
| 9 | #include <stdio.h> |
| 10 | #include <stdlib.h> |
| 11 | #include <string.h> |
| 12 | #include <sys/stat.h> |
| 13 | #include <sys/types.h> |
| 14 | #include <sys/wait.h> |
| 15 | #include <unistd.h> |
| 16 | |
| 17 | #include "cgroup_util.h" |
| 18 | |
| 19 | static ssize_t read_text(const char *path, char *buf, size_t max_len) |
| 20 | { |
| 21 | ssize_t len; |
| 22 | int fd; |
| 23 | |
| 24 | fd = open(path, O_RDONLY); |
| 25 | if (fd < 0) |
| 26 | return fd; |
| 27 | |
| 28 | len = read(fd, buf, max_len - 1); |
| 29 | if (len < 0) |
| 30 | goto out; |
| 31 | |
| 32 | buf[len] = 0; |
| 33 | out: |
| 34 | close(fd); |
| 35 | return len; |
| 36 | } |
| 37 | |
Dan Carpenter | 53c3daf | 2018-06-07 11:30:02 +0300 | [diff] [blame] | 38 | static ssize_t write_text(const char *path, char *buf, ssize_t len) |
Roman Gushchin | 84092dbc | 2018-05-11 19:03:49 +0100 | [diff] [blame] | 39 | { |
| 40 | int fd; |
| 41 | |
| 42 | fd = open(path, O_WRONLY | O_APPEND); |
| 43 | if (fd < 0) |
| 44 | return fd; |
| 45 | |
| 46 | len = write(fd, buf, len); |
| 47 | if (len < 0) { |
| 48 | close(fd); |
| 49 | return len; |
| 50 | } |
| 51 | |
| 52 | close(fd); |
| 53 | |
| 54 | return len; |
| 55 | } |
| 56 | |
| 57 | char *cg_name(const char *root, const char *name) |
| 58 | { |
| 59 | size_t len = strlen(root) + strlen(name) + 2; |
| 60 | char *ret = malloc(len); |
| 61 | |
Roman Gushchin | adb31be | 2018-05-22 11:10:31 +0100 | [diff] [blame] | 62 | snprintf(ret, len, "%s/%s", root, name); |
Roman Gushchin | 84092dbc | 2018-05-11 19:03:49 +0100 | [diff] [blame] | 63 | |
| 64 | return ret; |
| 65 | } |
| 66 | |
| 67 | char *cg_name_indexed(const char *root, const char *name, int index) |
| 68 | { |
| 69 | size_t len = strlen(root) + strlen(name) + 10; |
| 70 | char *ret = malloc(len); |
| 71 | |
Roman Gushchin | adb31be | 2018-05-22 11:10:31 +0100 | [diff] [blame] | 72 | snprintf(ret, len, "%s/%s_%d", root, name, index); |
Roman Gushchin | 84092dbc | 2018-05-11 19:03:49 +0100 | [diff] [blame] | 73 | |
| 74 | return ret; |
| 75 | } |
| 76 | |
Roman Gushchin | 5313bfe | 2019-04-19 10:03:06 -0700 | [diff] [blame] | 77 | char *cg_control(const char *cgroup, const char *control) |
| 78 | { |
| 79 | size_t len = strlen(cgroup) + strlen(control) + 2; |
| 80 | char *ret = malloc(len); |
| 81 | |
| 82 | snprintf(ret, len, "%s/%s", cgroup, control); |
| 83 | |
| 84 | return ret; |
| 85 | } |
| 86 | |
Roman Gushchin | 84092dbc | 2018-05-11 19:03:49 +0100 | [diff] [blame] | 87 | int cg_read(const char *cgroup, const char *control, char *buf, size_t len) |
| 88 | { |
| 89 | char path[PATH_MAX]; |
| 90 | |
| 91 | snprintf(path, sizeof(path), "%s/%s", cgroup, control); |
| 92 | |
| 93 | if (read_text(path, buf, len) >= 0) |
| 94 | return 0; |
| 95 | |
| 96 | return -1; |
| 97 | } |
| 98 | |
| 99 | int cg_read_strcmp(const char *cgroup, const char *control, |
| 100 | const char *expected) |
| 101 | { |
Jay Kamat | 48c2bb0 | 2018-09-07 14:34:04 -0700 | [diff] [blame] | 102 | size_t size; |
Roman Gushchin | 84092dbc | 2018-05-11 19:03:49 +0100 | [diff] [blame] | 103 | char *buf; |
Jay Kamat | 48c2bb0 | 2018-09-07 14:34:04 -0700 | [diff] [blame] | 104 | int ret; |
| 105 | |
| 106 | /* Handle the case of comparing against empty string */ |
| 107 | if (!expected) |
| 108 | size = 32; |
| 109 | else |
| 110 | size = strlen(expected) + 1; |
Roman Gushchin | 84092dbc | 2018-05-11 19:03:49 +0100 | [diff] [blame] | 111 | |
| 112 | buf = malloc(size); |
| 113 | if (!buf) |
| 114 | return -1; |
| 115 | |
Jay Kamat | 48c2bb0 | 2018-09-07 14:34:04 -0700 | [diff] [blame] | 116 | if (cg_read(cgroup, control, buf, size)) { |
| 117 | free(buf); |
Roman Gushchin | 84092dbc | 2018-05-11 19:03:49 +0100 | [diff] [blame] | 118 | return -1; |
Jay Kamat | 48c2bb0 | 2018-09-07 14:34:04 -0700 | [diff] [blame] | 119 | } |
Roman Gushchin | 84092dbc | 2018-05-11 19:03:49 +0100 | [diff] [blame] | 120 | |
Jay Kamat | 48c2bb0 | 2018-09-07 14:34:04 -0700 | [diff] [blame] | 121 | ret = strcmp(expected, buf); |
| 122 | free(buf); |
| 123 | return ret; |
Roman Gushchin | 84092dbc | 2018-05-11 19:03:49 +0100 | [diff] [blame] | 124 | } |
| 125 | |
| 126 | int cg_read_strstr(const char *cgroup, const char *control, const char *needle) |
| 127 | { |
| 128 | char buf[PAGE_SIZE]; |
| 129 | |
| 130 | if (cg_read(cgroup, control, buf, sizeof(buf))) |
| 131 | return -1; |
| 132 | |
| 133 | return strstr(buf, needle) ? 0 : -1; |
| 134 | } |
| 135 | |
| 136 | long cg_read_long(const char *cgroup, const char *control) |
| 137 | { |
| 138 | char buf[128]; |
| 139 | |
| 140 | if (cg_read(cgroup, control, buf, sizeof(buf))) |
| 141 | return -1; |
| 142 | |
| 143 | return atol(buf); |
| 144 | } |
| 145 | |
| 146 | long cg_read_key_long(const char *cgroup, const char *control, const char *key) |
| 147 | { |
| 148 | char buf[PAGE_SIZE]; |
| 149 | char *ptr; |
| 150 | |
| 151 | if (cg_read(cgroup, control, buf, sizeof(buf))) |
| 152 | return -1; |
| 153 | |
| 154 | ptr = strstr(buf, key); |
| 155 | if (!ptr) |
| 156 | return -1; |
| 157 | |
| 158 | return atol(ptr + strlen(key)); |
| 159 | } |
| 160 | |
Michal Koutný | 1131898 | 2019-10-04 12:57:42 +0200 | [diff] [blame] | 161 | long cg_read_lc(const char *cgroup, const char *control) |
| 162 | { |
| 163 | char buf[PAGE_SIZE]; |
| 164 | const char delim[] = "\n"; |
| 165 | char *line; |
| 166 | long cnt = 0; |
| 167 | |
| 168 | if (cg_read(cgroup, control, buf, sizeof(buf))) |
| 169 | return -1; |
| 170 | |
| 171 | for (line = strtok(buf, delim); line; line = strtok(NULL, delim)) |
| 172 | cnt++; |
| 173 | |
| 174 | return cnt; |
| 175 | } |
| 176 | |
Roman Gushchin | 84092dbc | 2018-05-11 19:03:49 +0100 | [diff] [blame] | 177 | int cg_write(const char *cgroup, const char *control, char *buf) |
| 178 | { |
| 179 | char path[PATH_MAX]; |
Dan Carpenter | 53c3daf | 2018-06-07 11:30:02 +0300 | [diff] [blame] | 180 | ssize_t len = strlen(buf); |
Roman Gushchin | 84092dbc | 2018-05-11 19:03:49 +0100 | [diff] [blame] | 181 | |
| 182 | snprintf(path, sizeof(path), "%s/%s", cgroup, control); |
| 183 | |
| 184 | if (write_text(path, buf, len) == len) |
| 185 | return 0; |
| 186 | |
| 187 | return -1; |
| 188 | } |
| 189 | |
| 190 | int cg_find_unified_root(char *root, size_t len) |
| 191 | { |
| 192 | char buf[10 * PAGE_SIZE]; |
| 193 | char *fs, *mount, *type; |
| 194 | const char delim[] = "\n\t "; |
| 195 | |
| 196 | if (read_text("/proc/self/mounts", buf, sizeof(buf)) <= 0) |
| 197 | return -1; |
| 198 | |
| 199 | /* |
| 200 | * Example: |
| 201 | * cgroup /sys/fs/cgroup cgroup2 rw,seclabel,noexec,relatime 0 0 |
| 202 | */ |
| 203 | for (fs = strtok(buf, delim); fs; fs = strtok(NULL, delim)) { |
| 204 | mount = strtok(NULL, delim); |
| 205 | type = strtok(NULL, delim); |
| 206 | strtok(NULL, delim); |
| 207 | strtok(NULL, delim); |
| 208 | strtok(NULL, delim); |
| 209 | |
Chris Down | b59b1ba | 2019-08-02 21:49:15 -0700 | [diff] [blame] | 210 | if (strcmp(type, "cgroup2") == 0) { |
Roman Gushchin | 84092dbc | 2018-05-11 19:03:49 +0100 | [diff] [blame] | 211 | strncpy(root, mount, len); |
| 212 | return 0; |
| 213 | } |
| 214 | } |
| 215 | |
| 216 | return -1; |
| 217 | } |
| 218 | |
| 219 | int cg_create(const char *cgroup) |
| 220 | { |
| 221 | return mkdir(cgroup, 0644); |
| 222 | } |
| 223 | |
Roman Gushchin | 5313bfe | 2019-04-19 10:03:06 -0700 | [diff] [blame] | 224 | int cg_wait_for_proc_count(const char *cgroup, int count) |
| 225 | { |
| 226 | char buf[10 * PAGE_SIZE] = {0}; |
| 227 | int attempts; |
| 228 | char *ptr; |
| 229 | |
| 230 | for (attempts = 10; attempts >= 0; attempts--) { |
| 231 | int nr = 0; |
| 232 | |
| 233 | if (cg_read(cgroup, "cgroup.procs", buf, sizeof(buf))) |
| 234 | break; |
| 235 | |
| 236 | for (ptr = buf; *ptr; ptr++) |
| 237 | if (*ptr == '\n') |
| 238 | nr++; |
| 239 | |
| 240 | if (nr >= count) |
| 241 | return 0; |
| 242 | |
| 243 | usleep(100000); |
| 244 | } |
| 245 | |
| 246 | return -1; |
| 247 | } |
| 248 | |
| 249 | int cg_killall(const char *cgroup) |
Roman Gushchin | 84092dbc | 2018-05-11 19:03:49 +0100 | [diff] [blame] | 250 | { |
| 251 | char buf[PAGE_SIZE]; |
| 252 | char *ptr = buf; |
| 253 | |
| 254 | if (cg_read(cgroup, "cgroup.procs", buf, sizeof(buf))) |
| 255 | return -1; |
| 256 | |
| 257 | while (ptr < buf + sizeof(buf)) { |
| 258 | int pid = strtol(ptr, &ptr, 10); |
| 259 | |
| 260 | if (pid == 0) |
| 261 | break; |
| 262 | if (*ptr) |
| 263 | ptr++; |
| 264 | else |
| 265 | break; |
| 266 | if (kill(pid, SIGKILL)) |
| 267 | return -1; |
| 268 | } |
| 269 | |
| 270 | return 0; |
| 271 | } |
| 272 | |
| 273 | int cg_destroy(const char *cgroup) |
| 274 | { |
| 275 | int ret; |
| 276 | |
| 277 | retry: |
| 278 | ret = rmdir(cgroup); |
| 279 | if (ret && errno == EBUSY) { |
Roman Gushchin | ff9fb7cb | 2019-04-19 10:03:05 -0700 | [diff] [blame] | 280 | cg_killall(cgroup); |
Roman Gushchin | 84092dbc | 2018-05-11 19:03:49 +0100 | [diff] [blame] | 281 | usleep(100); |
| 282 | goto retry; |
| 283 | } |
| 284 | |
| 285 | if (ret && errno == ENOENT) |
| 286 | ret = 0; |
| 287 | |
| 288 | return ret; |
| 289 | } |
| 290 | |
Roman Gushchin | 5313bfe | 2019-04-19 10:03:06 -0700 | [diff] [blame] | 291 | int cg_enter(const char *cgroup, int pid) |
| 292 | { |
| 293 | char pidbuf[64]; |
| 294 | |
| 295 | snprintf(pidbuf, sizeof(pidbuf), "%d", pid); |
| 296 | return cg_write(cgroup, "cgroup.procs", pidbuf); |
| 297 | } |
| 298 | |
Claudio | d863cb03fc | 2018-07-18 19:33:58 +0200 | [diff] [blame] | 299 | int cg_enter_current(const char *cgroup) |
| 300 | { |
Michal Koutný | 58c9f75 | 2019-10-04 12:57:41 +0200 | [diff] [blame] | 301 | return cg_write(cgroup, "cgroup.procs", "0"); |
| 302 | } |
Claudio | d863cb03fc | 2018-07-18 19:33:58 +0200 | [diff] [blame] | 303 | |
Michal Koutný | 58c9f75 | 2019-10-04 12:57:41 +0200 | [diff] [blame] | 304 | int cg_enter_current_thread(const char *cgroup) |
| 305 | { |
| 306 | return cg_write(cgroup, "cgroup.threads", "0"); |
Claudio | d863cb03fc | 2018-07-18 19:33:58 +0200 | [diff] [blame] | 307 | } |
| 308 | |
Roman Gushchin | 84092dbc | 2018-05-11 19:03:49 +0100 | [diff] [blame] | 309 | int cg_run(const char *cgroup, |
| 310 | int (*fn)(const char *cgroup, void *arg), |
| 311 | void *arg) |
| 312 | { |
| 313 | int pid, retcode; |
| 314 | |
| 315 | pid = fork(); |
| 316 | if (pid < 0) { |
| 317 | return pid; |
| 318 | } else if (pid == 0) { |
| 319 | char buf[64]; |
| 320 | |
| 321 | snprintf(buf, sizeof(buf), "%d", getpid()); |
| 322 | if (cg_write(cgroup, "cgroup.procs", buf)) |
| 323 | exit(EXIT_FAILURE); |
| 324 | exit(fn(cgroup, arg)); |
| 325 | } else { |
| 326 | waitpid(pid, &retcode, 0); |
| 327 | if (WIFEXITED(retcode)) |
| 328 | return WEXITSTATUS(retcode); |
| 329 | else |
| 330 | return -1; |
| 331 | } |
| 332 | } |
| 333 | |
| 334 | int cg_run_nowait(const char *cgroup, |
| 335 | int (*fn)(const char *cgroup, void *arg), |
| 336 | void *arg) |
| 337 | { |
| 338 | int pid; |
| 339 | |
| 340 | pid = fork(); |
| 341 | if (pid == 0) { |
| 342 | char buf[64]; |
| 343 | |
| 344 | snprintf(buf, sizeof(buf), "%d", getpid()); |
| 345 | if (cg_write(cgroup, "cgroup.procs", buf)) |
| 346 | exit(EXIT_FAILURE); |
| 347 | exit(fn(cgroup, arg)); |
| 348 | } |
| 349 | |
| 350 | return pid; |
| 351 | } |
| 352 | |
| 353 | int get_temp_fd(void) |
| 354 | { |
| 355 | return open(".", O_TMPFILE | O_RDWR | O_EXCL); |
| 356 | } |
| 357 | |
| 358 | int alloc_pagecache(int fd, size_t size) |
| 359 | { |
| 360 | char buf[PAGE_SIZE]; |
| 361 | struct stat st; |
| 362 | int i; |
| 363 | |
| 364 | if (fstat(fd, &st)) |
| 365 | goto cleanup; |
| 366 | |
| 367 | size += st.st_size; |
| 368 | |
| 369 | if (ftruncate(fd, size)) |
| 370 | goto cleanup; |
| 371 | |
| 372 | for (i = 0; i < size; i += sizeof(buf)) |
| 373 | read(fd, buf, sizeof(buf)); |
| 374 | |
| 375 | return 0; |
| 376 | |
| 377 | cleanup: |
| 378 | return -1; |
| 379 | } |
| 380 | |
| 381 | int alloc_anon(const char *cgroup, void *arg) |
| 382 | { |
| 383 | size_t size = (unsigned long)arg; |
| 384 | char *buf, *ptr; |
| 385 | |
| 386 | buf = malloc(size); |
| 387 | for (ptr = buf; ptr < buf + size; ptr += PAGE_SIZE) |
| 388 | *ptr = 0; |
| 389 | |
| 390 | free(buf); |
| 391 | return 0; |
| 392 | } |
Mike Rapoport | 478b278 | 2018-05-15 19:05:53 +0300 | [diff] [blame] | 393 | |
| 394 | int is_swap_enabled(void) |
| 395 | { |
| 396 | char buf[PAGE_SIZE]; |
| 397 | const char delim[] = "\n"; |
| 398 | int cnt = 0; |
| 399 | char *line; |
| 400 | |
| 401 | if (read_text("/proc/swaps", buf, sizeof(buf)) <= 0) |
| 402 | return -1; |
| 403 | |
| 404 | for (line = strtok(buf, delim); line; line = strtok(NULL, delim)) |
| 405 | cnt++; |
| 406 | |
| 407 | return cnt > 1; |
| 408 | } |
Jay Kamat | a987785 | 2018-09-07 14:34:05 -0700 | [diff] [blame] | 409 | |
| 410 | int set_oom_adj_score(int pid, int score) |
| 411 | { |
| 412 | char path[PATH_MAX]; |
| 413 | int fd, len; |
| 414 | |
| 415 | sprintf(path, "/proc/%d/oom_score_adj", pid); |
| 416 | |
| 417 | fd = open(path, O_WRONLY | O_APPEND); |
| 418 | if (fd < 0) |
| 419 | return fd; |
| 420 | |
| 421 | len = dprintf(fd, "%d", score); |
| 422 | if (len < 0) { |
| 423 | close(fd); |
| 424 | return len; |
| 425 | } |
| 426 | |
| 427 | close(fd); |
| 428 | return 0; |
| 429 | } |
Roman Gushchin | 5313bfe | 2019-04-19 10:03:06 -0700 | [diff] [blame] | 430 | |
Michal Koutný | 58c9f75 | 2019-10-04 12:57:41 +0200 | [diff] [blame] | 431 | ssize_t proc_read_text(int pid, bool thread, const char *item, char *buf, size_t size) |
Roman Gushchin | 5313bfe | 2019-04-19 10:03:06 -0700 | [diff] [blame] | 432 | { |
| 433 | char path[PATH_MAX]; |
| 434 | |
Michal Koutný | 58c9f75 | 2019-10-04 12:57:41 +0200 | [diff] [blame] | 435 | if (!pid) |
| 436 | snprintf(path, sizeof(path), "/proc/%s/%s", |
| 437 | thread ? "thread-self" : "self", item); |
| 438 | else |
| 439 | snprintf(path, sizeof(path), "/proc/%d/%s", pid, item); |
Roman Gushchin | 5313bfe | 2019-04-19 10:03:06 -0700 | [diff] [blame] | 440 | |
| 441 | return read_text(path, buf, size); |
| 442 | } |
Michal Koutný | 1131898 | 2019-10-04 12:57:42 +0200 | [diff] [blame] | 443 | |
| 444 | int proc_read_strstr(int pid, bool thread, const char *item, const char *needle) |
| 445 | { |
| 446 | char buf[PAGE_SIZE]; |
| 447 | |
| 448 | if (proc_read_text(pid, thread, item, buf, sizeof(buf)) < 0) |
| 449 | return -1; |
| 450 | |
| 451 | return strstr(buf, needle) ? 0 : -1; |
| 452 | } |