bpf.c 8.1 KB

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  1. // SPDX-License-Identifier: GPL-2.0
  2. #include <errno.h>
  3. #include <stdio.h>
  4. #include <stdlib.h>
  5. #include <sys/epoll.h>
  6. #include <sys/types.h>
  7. #include <sys/stat.h>
  8. #include <fcntl.h>
  9. #include <util/record.h>
  10. #include <util/util.h>
  11. #include <util/bpf-loader.h>
  12. #include <util/evlist.h>
  13. #include <linux/bpf.h>
  14. #include <linux/filter.h>
  15. #include <linux/kernel.h>
  16. #include <linux/string.h>
  17. #include <api/fs/fs.h>
  18. #include <bpf/bpf.h>
  19. #include <perf/mmap.h>
  20. #include "tests.h"
  21. #include "llvm.h"
  22. #include "debug.h"
  23. #include "parse-events.h"
  24. #include "util/mmap.h"
  25. #define NR_ITERS 111
  26. #define PERF_TEST_BPF_PATH "/sys/fs/bpf/perf_test"
  27. #ifdef HAVE_LIBBPF_SUPPORT
  28. static int epoll_pwait_loop(void)
  29. {
  30. int i;
  31. /* Should fail NR_ITERS times */
  32. for (i = 0; i < NR_ITERS; i++)
  33. epoll_pwait(-(i + 1), NULL, 0, 0, NULL);
  34. return 0;
  35. }
  36. #ifdef HAVE_BPF_PROLOGUE
  37. static int llseek_loop(void)
  38. {
  39. int fds[2], i;
  40. fds[0] = open("/dev/null", O_RDONLY);
  41. fds[1] = open("/dev/null", O_RDWR);
  42. if (fds[0] < 0 || fds[1] < 0)
  43. return -1;
  44. for (i = 0; i < NR_ITERS; i++) {
  45. lseek(fds[i % 2], i, (i / 2) % 2 ? SEEK_CUR : SEEK_SET);
  46. lseek(fds[(i + 1) % 2], i, (i / 2) % 2 ? SEEK_CUR : SEEK_SET);
  47. }
  48. close(fds[0]);
  49. close(fds[1]);
  50. return 0;
  51. }
  52. #endif
  53. static struct {
  54. enum test_llvm__testcase prog_id;
  55. const char *desc;
  56. const char *name;
  57. const char *msg_compile_fail;
  58. const char *msg_load_fail;
  59. int (*target_func)(void);
  60. int expect_result;
  61. bool pin;
  62. } bpf_testcase_table[] = {
  63. {
  64. .prog_id = LLVM_TESTCASE_BASE,
  65. .desc = "Basic BPF filtering",
  66. .name = "[basic_bpf_test]",
  67. .msg_compile_fail = "fix 'perf test LLVM' first",
  68. .msg_load_fail = "load bpf object failed",
  69. .target_func = &epoll_pwait_loop,
  70. .expect_result = (NR_ITERS + 1) / 2,
  71. },
  72. {
  73. .prog_id = LLVM_TESTCASE_BASE,
  74. .desc = "BPF pinning",
  75. .name = "[bpf_pinning]",
  76. .msg_compile_fail = "fix kbuild first",
  77. .msg_load_fail = "check your vmlinux setting?",
  78. .target_func = &epoll_pwait_loop,
  79. .expect_result = (NR_ITERS + 1) / 2,
  80. .pin = true,
  81. },
  82. #ifdef HAVE_BPF_PROLOGUE
  83. {
  84. .prog_id = LLVM_TESTCASE_BPF_PROLOGUE,
  85. .desc = "BPF prologue generation",
  86. .name = "[bpf_prologue_test]",
  87. .msg_compile_fail = "fix kbuild first",
  88. .msg_load_fail = "check your vmlinux setting?",
  89. .target_func = &llseek_loop,
  90. .expect_result = (NR_ITERS + 1) / 4,
  91. },
  92. #endif
  93. {
  94. .prog_id = LLVM_TESTCASE_BPF_RELOCATION,
  95. .desc = "BPF relocation checker",
  96. .name = "[bpf_relocation_test]",
  97. .msg_compile_fail = "fix 'perf test LLVM' first",
  98. .msg_load_fail = "libbpf error when dealing with relocation",
  99. },
  100. };
  101. static int do_test(struct bpf_object *obj, int (*func)(void),
  102. int expect)
  103. {
  104. struct record_opts opts = {
  105. .target = {
  106. .uid = UINT_MAX,
  107. .uses_mmap = true,
  108. },
  109. .freq = 0,
  110. .mmap_pages = 256,
  111. .default_interval = 1,
  112. };
  113. char pid[16];
  114. char sbuf[STRERR_BUFSIZE];
  115. struct evlist *evlist;
  116. int i, ret = TEST_FAIL, err = 0, count = 0;
  117. struct parse_events_state parse_state;
  118. struct parse_events_error parse_error;
  119. bzero(&parse_error, sizeof(parse_error));
  120. bzero(&parse_state, sizeof(parse_state));
  121. parse_state.error = &parse_error;
  122. INIT_LIST_HEAD(&parse_state.list);
  123. err = parse_events_load_bpf_obj(&parse_state, &parse_state.list, obj, NULL);
  124. if (err || list_empty(&parse_state.list)) {
  125. pr_debug("Failed to add events selected by BPF\n");
  126. return TEST_FAIL;
  127. }
  128. snprintf(pid, sizeof(pid), "%d", getpid());
  129. pid[sizeof(pid) - 1] = '\0';
  130. opts.target.tid = opts.target.pid = pid;
  131. /* Instead of perf_evlist__new_default, don't add default events */
  132. evlist = evlist__new();
  133. if (!evlist) {
  134. pr_debug("Not enough memory to create evlist\n");
  135. return TEST_FAIL;
  136. }
  137. err = perf_evlist__create_maps(evlist, &opts.target);
  138. if (err < 0) {
  139. pr_debug("Not enough memory to create thread/cpu maps\n");
  140. goto out_delete_evlist;
  141. }
  142. perf_evlist__splice_list_tail(evlist, &parse_state.list);
  143. evlist->nr_groups = parse_state.nr_groups;
  144. perf_evlist__config(evlist, &opts, NULL);
  145. err = evlist__open(evlist);
  146. if (err < 0) {
  147. pr_debug("perf_evlist__open: %s\n",
  148. str_error_r(errno, sbuf, sizeof(sbuf)));
  149. goto out_delete_evlist;
  150. }
  151. err = evlist__mmap(evlist, opts.mmap_pages);
  152. if (err < 0) {
  153. pr_debug("evlist__mmap: %s\n",
  154. str_error_r(errno, sbuf, sizeof(sbuf)));
  155. goto out_delete_evlist;
  156. }
  157. evlist__enable(evlist);
  158. (*func)();
  159. evlist__disable(evlist);
  160. for (i = 0; i < evlist->core.nr_mmaps; i++) {
  161. union perf_event *event;
  162. struct mmap *md;
  163. md = &evlist->mmap[i];
  164. if (perf_mmap__read_init(&md->core) < 0)
  165. continue;
  166. while ((event = perf_mmap__read_event(&md->core)) != NULL) {
  167. const u32 type = event->header.type;
  168. if (type == PERF_RECORD_SAMPLE)
  169. count ++;
  170. }
  171. perf_mmap__read_done(&md->core);
  172. }
  173. if (count != expect * evlist->core.nr_entries) {
  174. pr_debug("BPF filter result incorrect, expected %d, got %d samples\n", expect * evlist->core.nr_entries, count);
  175. goto out_delete_evlist;
  176. }
  177. ret = TEST_OK;
  178. out_delete_evlist:
  179. evlist__delete(evlist);
  180. return ret;
  181. }
  182. static struct bpf_object *
  183. prepare_bpf(void *obj_buf, size_t obj_buf_sz, const char *name)
  184. {
  185. struct bpf_object *obj;
  186. obj = bpf__prepare_load_buffer(obj_buf, obj_buf_sz, name);
  187. if (IS_ERR(obj)) {
  188. pr_debug("Compile BPF program failed.\n");
  189. return NULL;
  190. }
  191. return obj;
  192. }
  193. static int __test__bpf(int idx)
  194. {
  195. int ret;
  196. void *obj_buf;
  197. size_t obj_buf_sz;
  198. struct bpf_object *obj;
  199. ret = test_llvm__fetch_bpf_obj(&obj_buf, &obj_buf_sz,
  200. bpf_testcase_table[idx].prog_id,
  201. true, NULL);
  202. if (ret != TEST_OK || !obj_buf || !obj_buf_sz) {
  203. pr_debug("Unable to get BPF object, %s\n",
  204. bpf_testcase_table[idx].msg_compile_fail);
  205. if (idx == 0)
  206. return TEST_SKIP;
  207. else
  208. return TEST_FAIL;
  209. }
  210. obj = prepare_bpf(obj_buf, obj_buf_sz,
  211. bpf_testcase_table[idx].name);
  212. if ((!!bpf_testcase_table[idx].target_func) != (!!obj)) {
  213. if (!obj)
  214. pr_debug("Fail to load BPF object: %s\n",
  215. bpf_testcase_table[idx].msg_load_fail);
  216. else
  217. pr_debug("Success unexpectedly: %s\n",
  218. bpf_testcase_table[idx].msg_load_fail);
  219. ret = TEST_FAIL;
  220. goto out;
  221. }
  222. if (obj) {
  223. ret = do_test(obj,
  224. bpf_testcase_table[idx].target_func,
  225. bpf_testcase_table[idx].expect_result);
  226. if (ret != TEST_OK)
  227. goto out;
  228. if (bpf_testcase_table[idx].pin) {
  229. int err;
  230. if (!bpf_fs__mount()) {
  231. pr_debug("BPF filesystem not mounted\n");
  232. ret = TEST_FAIL;
  233. goto out;
  234. }
  235. err = mkdir(PERF_TEST_BPF_PATH, 0777);
  236. if (err && errno != EEXIST) {
  237. pr_debug("Failed to make perf_test dir: %s\n",
  238. strerror(errno));
  239. ret = TEST_FAIL;
  240. goto out;
  241. }
  242. if (bpf_object__pin(obj, PERF_TEST_BPF_PATH))
  243. ret = TEST_FAIL;
  244. if (rm_rf(PERF_TEST_BPF_PATH))
  245. ret = TEST_FAIL;
  246. }
  247. }
  248. out:
  249. free(obj_buf);
  250. bpf__clear();
  251. return ret;
  252. }
  253. int test__bpf_subtest_get_nr(void)
  254. {
  255. return (int)ARRAY_SIZE(bpf_testcase_table);
  256. }
  257. const char *test__bpf_subtest_get_desc(int i)
  258. {
  259. if (i < 0 || i >= (int)ARRAY_SIZE(bpf_testcase_table))
  260. return NULL;
  261. return bpf_testcase_table[i].desc;
  262. }
  263. static int check_env(void)
  264. {
  265. int err;
  266. unsigned int kver_int;
  267. char license[] = "GPL";
  268. struct bpf_insn insns[] = {
  269. BPF_MOV64_IMM(BPF_REG_0, 1),
  270. BPF_EXIT_INSN(),
  271. };
  272. err = fetch_kernel_version(&kver_int, NULL, 0);
  273. if (err) {
  274. pr_debug("Unable to get kernel version\n");
  275. return err;
  276. }
  277. err = bpf_load_program(BPF_PROG_TYPE_KPROBE, insns,
  278. sizeof(insns) / sizeof(insns[0]),
  279. license, kver_int, NULL, 0);
  280. if (err < 0) {
  281. pr_err("Missing basic BPF support, skip this test: %s\n",
  282. strerror(errno));
  283. return err;
  284. }
  285. close(err);
  286. return 0;
  287. }
  288. int test__bpf(struct test *test __maybe_unused, int i)
  289. {
  290. int err;
  291. if (i < 0 || i >= (int)ARRAY_SIZE(bpf_testcase_table))
  292. return TEST_FAIL;
  293. if (geteuid() != 0) {
  294. pr_debug("Only root can run BPF test\n");
  295. return TEST_SKIP;
  296. }
  297. if (check_env())
  298. return TEST_SKIP;
  299. err = __test__bpf(i);
  300. return err;
  301. }
  302. #else
  303. int test__bpf_subtest_get_nr(void)
  304. {
  305. return 0;
  306. }
  307. const char *test__bpf_subtest_get_desc(int i __maybe_unused)
  308. {
  309. return NULL;
  310. }
  311. int test__bpf(struct test *test __maybe_unused, int i __maybe_unused)
  312. {
  313. pr_debug("Skip BPF test because BPF support is not compiled\n");
  314. return TEST_SKIP;
  315. }
  316. #endif