0001
0002 #include <errno.h>
0003 #include <stdio.h>
0004 #include <stdlib.h>
0005 #include <sys/epoll.h>
0006 #include <sys/types.h>
0007 #include <sys/stat.h>
0008 #include <fcntl.h>
0009 #include <util/record.h>
0010 #include <util/util.h>
0011 #include <util/bpf-loader.h>
0012 #include <util/evlist.h>
0013 #include <linux/filter.h>
0014 #include <linux/kernel.h>
0015 #include <linux/string.h>
0016 #include <api/fs/fs.h>
0017 #include <perf/mmap.h>
0018 #include "tests.h"
0019 #include "llvm.h"
0020 #include "debug.h"
0021 #include "parse-events.h"
0022 #include "util/mmap.h"
0023 #define NR_ITERS 111
0024 #define PERF_TEST_BPF_PATH "/sys/fs/bpf/perf_test"
0025
0026 #ifdef HAVE_LIBBPF_SUPPORT
0027 #include <linux/bpf.h>
0028 #include <bpf/bpf.h>
0029
0030 static int epoll_pwait_loop(void)
0031 {
0032 int i;
0033
0034
0035 for (i = 0; i < NR_ITERS; i++)
0036 epoll_pwait(-(i + 1), NULL, 0, 0, NULL);
0037 return 0;
0038 }
0039
0040 #ifdef HAVE_BPF_PROLOGUE
0041
0042 static int llseek_loop(void)
0043 {
0044 int fds[2], i;
0045
0046 fds[0] = open("/dev/null", O_RDONLY);
0047 fds[1] = open("/dev/null", O_RDWR);
0048
0049 if (fds[0] < 0 || fds[1] < 0)
0050 return -1;
0051
0052 for (i = 0; i < NR_ITERS; i++) {
0053 lseek(fds[i % 2], i, (i / 2) % 2 ? SEEK_CUR : SEEK_SET);
0054 lseek(fds[(i + 1) % 2], i, (i / 2) % 2 ? SEEK_CUR : SEEK_SET);
0055 }
0056 close(fds[0]);
0057 close(fds[1]);
0058 return 0;
0059 }
0060
0061 #endif
0062
0063 static struct {
0064 enum test_llvm__testcase prog_id;
0065 const char *name;
0066 const char *msg_compile_fail;
0067 const char *msg_load_fail;
0068 int (*target_func)(void);
0069 int expect_result;
0070 bool pin;
0071 } bpf_testcase_table[] = {
0072 {
0073 .prog_id = LLVM_TESTCASE_BASE,
0074 .name = "[basic_bpf_test]",
0075 .msg_compile_fail = "fix 'perf test LLVM' first",
0076 .msg_load_fail = "load bpf object failed",
0077 .target_func = &epoll_pwait_loop,
0078 .expect_result = (NR_ITERS + 1) / 2,
0079 },
0080 {
0081 .prog_id = LLVM_TESTCASE_BASE,
0082 .name = "[bpf_pinning]",
0083 .msg_compile_fail = "fix kbuild first",
0084 .msg_load_fail = "check your vmlinux setting?",
0085 .target_func = &epoll_pwait_loop,
0086 .expect_result = (NR_ITERS + 1) / 2,
0087 .pin = true,
0088 },
0089 #ifdef HAVE_BPF_PROLOGUE
0090 {
0091 .prog_id = LLVM_TESTCASE_BPF_PROLOGUE,
0092 .name = "[bpf_prologue_test]",
0093 .msg_compile_fail = "fix kbuild first",
0094 .msg_load_fail = "check your vmlinux setting?",
0095 .target_func = &llseek_loop,
0096 .expect_result = (NR_ITERS + 1) / 4,
0097 },
0098 #endif
0099 };
0100
0101 static int do_test(struct bpf_object *obj, int (*func)(void),
0102 int expect)
0103 {
0104 struct record_opts opts = {
0105 .target = {
0106 .uid = UINT_MAX,
0107 .uses_mmap = true,
0108 },
0109 .freq = 0,
0110 .mmap_pages = 256,
0111 .default_interval = 1,
0112 };
0113
0114 char pid[16];
0115 char sbuf[STRERR_BUFSIZE];
0116 struct evlist *evlist;
0117 int i, ret = TEST_FAIL, err = 0, count = 0;
0118
0119 struct parse_events_state parse_state;
0120 struct parse_events_error parse_error;
0121
0122 parse_events_error__init(&parse_error);
0123 bzero(&parse_state, sizeof(parse_state));
0124 parse_state.error = &parse_error;
0125 INIT_LIST_HEAD(&parse_state.list);
0126
0127 err = parse_events_load_bpf_obj(&parse_state, &parse_state.list, obj, NULL);
0128 parse_events_error__exit(&parse_error);
0129 if (err || list_empty(&parse_state.list)) {
0130 pr_debug("Failed to add events selected by BPF\n");
0131 return TEST_FAIL;
0132 }
0133
0134 snprintf(pid, sizeof(pid), "%d", getpid());
0135 pid[sizeof(pid) - 1] = '\0';
0136 opts.target.tid = opts.target.pid = pid;
0137
0138
0139 evlist = evlist__new();
0140 if (!evlist) {
0141 pr_debug("Not enough memory to create evlist\n");
0142 return TEST_FAIL;
0143 }
0144
0145 err = evlist__create_maps(evlist, &opts.target);
0146 if (err < 0) {
0147 pr_debug("Not enough memory to create thread/cpu maps\n");
0148 goto out_delete_evlist;
0149 }
0150
0151 evlist__splice_list_tail(evlist, &parse_state.list);
0152 evlist->core.nr_groups = parse_state.nr_groups;
0153
0154 evlist__config(evlist, &opts, NULL);
0155
0156 err = evlist__open(evlist);
0157 if (err < 0) {
0158 pr_debug("perf_evlist__open: %s\n",
0159 str_error_r(errno, sbuf, sizeof(sbuf)));
0160 goto out_delete_evlist;
0161 }
0162
0163 err = evlist__mmap(evlist, opts.mmap_pages);
0164 if (err < 0) {
0165 pr_debug("evlist__mmap: %s\n",
0166 str_error_r(errno, sbuf, sizeof(sbuf)));
0167 goto out_delete_evlist;
0168 }
0169
0170 evlist__enable(evlist);
0171 (*func)();
0172 evlist__disable(evlist);
0173
0174 for (i = 0; i < evlist->core.nr_mmaps; i++) {
0175 union perf_event *event;
0176 struct mmap *md;
0177
0178 md = &evlist->mmap[i];
0179 if (perf_mmap__read_init(&md->core) < 0)
0180 continue;
0181
0182 while ((event = perf_mmap__read_event(&md->core)) != NULL) {
0183 const u32 type = event->header.type;
0184
0185 if (type == PERF_RECORD_SAMPLE)
0186 count ++;
0187 }
0188 perf_mmap__read_done(&md->core);
0189 }
0190
0191 if (count != expect * evlist->core.nr_entries) {
0192 pr_debug("BPF filter result incorrect, expected %d, got %d samples\n", expect * evlist->core.nr_entries, count);
0193 goto out_delete_evlist;
0194 }
0195
0196 ret = TEST_OK;
0197
0198 out_delete_evlist:
0199 evlist__delete(evlist);
0200 return ret;
0201 }
0202
0203 static struct bpf_object *
0204 prepare_bpf(void *obj_buf, size_t obj_buf_sz, const char *name)
0205 {
0206 struct bpf_object *obj;
0207
0208 obj = bpf__prepare_load_buffer(obj_buf, obj_buf_sz, name);
0209 if (IS_ERR(obj)) {
0210 pr_debug("Compile BPF program failed.\n");
0211 return NULL;
0212 }
0213 return obj;
0214 }
0215
0216 static int __test__bpf(int idx)
0217 {
0218 int ret;
0219 void *obj_buf;
0220 size_t obj_buf_sz;
0221 struct bpf_object *obj;
0222
0223 ret = test_llvm__fetch_bpf_obj(&obj_buf, &obj_buf_sz,
0224 bpf_testcase_table[idx].prog_id,
0225 false, NULL);
0226 if (ret != TEST_OK || !obj_buf || !obj_buf_sz) {
0227 pr_debug("Unable to get BPF object, %s\n",
0228 bpf_testcase_table[idx].msg_compile_fail);
0229 if ((idx == 0) || (ret == TEST_SKIP))
0230 return TEST_SKIP;
0231 else
0232 return TEST_FAIL;
0233 }
0234
0235 obj = prepare_bpf(obj_buf, obj_buf_sz,
0236 bpf_testcase_table[idx].name);
0237 if ((!!bpf_testcase_table[idx].target_func) != (!!obj)) {
0238 if (!obj)
0239 pr_debug("Fail to load BPF object: %s\n",
0240 bpf_testcase_table[idx].msg_load_fail);
0241 else
0242 pr_debug("Success unexpectedly: %s\n",
0243 bpf_testcase_table[idx].msg_load_fail);
0244 ret = TEST_FAIL;
0245 goto out;
0246 }
0247
0248 if (obj) {
0249 ret = do_test(obj,
0250 bpf_testcase_table[idx].target_func,
0251 bpf_testcase_table[idx].expect_result);
0252 if (ret != TEST_OK)
0253 goto out;
0254 if (bpf_testcase_table[idx].pin) {
0255 int err;
0256
0257 if (!bpf_fs__mount()) {
0258 pr_debug("BPF filesystem not mounted\n");
0259 ret = TEST_FAIL;
0260 goto out;
0261 }
0262 err = mkdir(PERF_TEST_BPF_PATH, 0777);
0263 if (err && errno != EEXIST) {
0264 pr_debug("Failed to make perf_test dir: %s\n",
0265 strerror(errno));
0266 ret = TEST_FAIL;
0267 goto out;
0268 }
0269 if (bpf_object__pin(obj, PERF_TEST_BPF_PATH))
0270 ret = TEST_FAIL;
0271 if (rm_rf(PERF_TEST_BPF_PATH))
0272 ret = TEST_FAIL;
0273 }
0274 }
0275
0276 out:
0277 free(obj_buf);
0278 bpf__clear();
0279 return ret;
0280 }
0281
0282 static int check_env(void)
0283 {
0284 LIBBPF_OPTS(bpf_prog_load_opts, opts);
0285 int err;
0286 char license[] = "GPL";
0287
0288 struct bpf_insn insns[] = {
0289 BPF_MOV64_IMM(BPF_REG_0, 1),
0290 BPF_EXIT_INSN(),
0291 };
0292
0293 err = fetch_kernel_version(&opts.kern_version, NULL, 0);
0294 if (err) {
0295 pr_debug("Unable to get kernel version\n");
0296 return err;
0297 }
0298 err = bpf_prog_load(BPF_PROG_TYPE_KPROBE, NULL, license, insns,
0299 ARRAY_SIZE(insns), &opts);
0300 if (err < 0) {
0301 pr_err("Missing basic BPF support, skip this test: %s\n",
0302 strerror(errno));
0303 return err;
0304 }
0305 close(err);
0306
0307 return 0;
0308 }
0309
0310 static int test__bpf(int i)
0311 {
0312 int err;
0313
0314 if (i < 0 || i >= (int)ARRAY_SIZE(bpf_testcase_table))
0315 return TEST_FAIL;
0316
0317 if (geteuid() != 0) {
0318 pr_debug("Only root can run BPF test\n");
0319 return TEST_SKIP;
0320 }
0321
0322 if (check_env())
0323 return TEST_SKIP;
0324
0325 err = __test__bpf(i);
0326 return err;
0327 }
0328 #endif
0329
0330 static int test__basic_bpf_test(struct test_suite *test __maybe_unused,
0331 int subtest __maybe_unused)
0332 {
0333 #ifdef HAVE_LIBBPF_SUPPORT
0334 return test__bpf(0);
0335 #else
0336 pr_debug("Skip BPF test because BPF support is not compiled\n");
0337 return TEST_SKIP;
0338 #endif
0339 }
0340
0341 static int test__bpf_pinning(struct test_suite *test __maybe_unused,
0342 int subtest __maybe_unused)
0343 {
0344 #ifdef HAVE_LIBBPF_SUPPORT
0345 return test__bpf(1);
0346 #else
0347 pr_debug("Skip BPF test because BPF support is not compiled\n");
0348 return TEST_SKIP;
0349 #endif
0350 }
0351
0352 static int test__bpf_prologue_test(struct test_suite *test __maybe_unused,
0353 int subtest __maybe_unused)
0354 {
0355 #if defined(HAVE_LIBBPF_SUPPORT) && defined(HAVE_BPF_PROLOGUE)
0356 return test__bpf(2);
0357 #else
0358 pr_debug("Skip BPF test because BPF support is not compiled\n");
0359 return TEST_SKIP;
0360 #endif
0361 }
0362
0363
0364 static struct test_case bpf_tests[] = {
0365 #ifdef HAVE_LIBBPF_SUPPORT
0366 TEST_CASE("Basic BPF filtering", basic_bpf_test),
0367 TEST_CASE_REASON("BPF pinning", bpf_pinning,
0368 "clang isn't installed or environment missing BPF support"),
0369 #ifdef HAVE_BPF_PROLOGUE
0370 TEST_CASE_REASON("BPF prologue generation", bpf_prologue_test,
0371 "clang isn't installed or environment missing BPF support"),
0372 #else
0373 TEST_CASE_REASON("BPF prologue generation", bpf_prologue_test, "not compiled in"),
0374 #endif
0375 #else
0376 TEST_CASE_REASON("Basic BPF filtering", basic_bpf_test, "not compiled in"),
0377 TEST_CASE_REASON("BPF pinning", bpf_pinning, "not compiled in"),
0378 TEST_CASE_REASON("BPF prologue generation", bpf_prologue_test, "not compiled in"),
0379 #endif
0380 { .name = NULL, }
0381 };
0382
0383 struct test_suite suite__bpf = {
0384 .desc = "BPF filter",
0385 .test_cases = bpf_tests,
0386 };
