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/filter.h>
14 #include <linux/kernel.h>
15 #include <linux/string.h>
16 #include <api/fs/fs.h>
17 #include <perf/mmap.h>
18 #include "tests.h"
19 #include "llvm.h"
20 #include "debug.h"
21 #include "parse-events.h"
22 #include "util/mmap.h"
23 #define NR_ITERS 111
24 #define PERF_TEST_BPF_PATH "/sys/fs/bpf/perf_test"
25
26 #if defined(HAVE_LIBBPF_SUPPORT) && defined(HAVE_LIBTRACEEVENT)
27 #include <linux/bpf.h>
28 #include <bpf/bpf.h>
29
epoll_pwait_loop(void)30 static int epoll_pwait_loop(void)
31 {
32 int i;
33
34 /* Should fail NR_ITERS times */
35 for (i = 0; i < NR_ITERS; i++)
36 epoll_pwait(-(i + 1), NULL, 0, 0, NULL);
37 return 0;
38 }
39
40 #ifdef HAVE_BPF_PROLOGUE
41
llseek_loop(void)42 static int llseek_loop(void)
43 {
44 int fds[2], i;
45
46 fds[0] = open("/dev/null", O_RDONLY);
47 fds[1] = open("/dev/null", O_RDWR);
48
49 if (fds[0] < 0 || fds[1] < 0)
50 return -1;
51
52 for (i = 0; i < NR_ITERS; i++) {
53 lseek(fds[i % 2], i, (i / 2) % 2 ? SEEK_CUR : SEEK_SET);
54 lseek(fds[(i + 1) % 2], i, (i / 2) % 2 ? SEEK_CUR : SEEK_SET);
55 }
56 close(fds[0]);
57 close(fds[1]);
58 return 0;
59 }
60
61 #endif
62
63 static struct {
64 enum test_llvm__testcase prog_id;
65 const char *name;
66 const char *msg_compile_fail;
67 const char *msg_load_fail;
68 int (*target_func)(void);
69 int expect_result;
70 bool pin;
71 } bpf_testcase_table[] = {
72 {
73 .prog_id = LLVM_TESTCASE_BASE,
74 .name = "[basic_bpf_test]",
75 .msg_compile_fail = "fix 'perf test LLVM' first",
76 .msg_load_fail = "load bpf object failed",
77 .target_func = &epoll_pwait_loop,
78 .expect_result = (NR_ITERS + 1) / 2,
79 },
80 {
81 .prog_id = LLVM_TESTCASE_BASE,
82 .name = "[bpf_pinning]",
83 .msg_compile_fail = "fix kbuild first",
84 .msg_load_fail = "check your vmlinux setting?",
85 .target_func = &epoll_pwait_loop,
86 .expect_result = (NR_ITERS + 1) / 2,
87 .pin = true,
88 },
89 #ifdef HAVE_BPF_PROLOGUE
90 {
91 .prog_id = LLVM_TESTCASE_BPF_PROLOGUE,
92 .name = "[bpf_prologue_test]",
93 .msg_compile_fail = "fix kbuild first",
94 .msg_load_fail = "check your vmlinux setting?",
95 .target_func = &llseek_loop,
96 .expect_result = (NR_ITERS + 1) / 4,
97 },
98 #endif
99 };
100
do_test(struct bpf_object * obj,int (* func)(void),int expect)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
114 char pid[16];
115 char sbuf[STRERR_BUFSIZE];
116 struct evlist *evlist;
117 int i, ret = TEST_FAIL, err = 0, count = 0;
118
119 struct parse_events_state parse_state;
120 struct parse_events_error parse_error;
121
122 parse_events_error__init(&parse_error);
123 bzero(&parse_state, sizeof(parse_state));
124 parse_state.error = &parse_error;
125 INIT_LIST_HEAD(&parse_state.list);
126
127 err = parse_events_load_bpf_obj(&parse_state, &parse_state.list, obj, NULL);
128 parse_events_error__exit(&parse_error);
129 if (err == -ENODATA) {
130 pr_debug("Failed to add events selected by BPF, debuginfo package not installed\n");
131 return TEST_SKIP;
132 }
133 if (err || list_empty(&parse_state.list)) {
134 pr_debug("Failed to add events selected by BPF\n");
135 return TEST_FAIL;
136 }
137
138 snprintf(pid, sizeof(pid), "%d", getpid());
139 pid[sizeof(pid) - 1] = '\0';
140 opts.target.tid = opts.target.pid = pid;
141
142 /* Instead of evlist__new_default, don't add default events */
143 evlist = evlist__new();
144 if (!evlist) {
145 pr_debug("Not enough memory to create evlist\n");
146 return TEST_FAIL;
147 }
148
149 err = evlist__create_maps(evlist, &opts.target);
150 if (err < 0) {
151 pr_debug("Not enough memory to create thread/cpu maps\n");
152 goto out_delete_evlist;
153 }
154
155 evlist__splice_list_tail(evlist, &parse_state.list);
156 evlist->core.nr_groups = parse_state.nr_groups;
157
158 evlist__config(evlist, &opts, NULL);
159
160 err = evlist__open(evlist);
161 if (err < 0) {
162 pr_debug("perf_evlist__open: %s\n",
163 str_error_r(errno, sbuf, sizeof(sbuf)));
164 goto out_delete_evlist;
165 }
166
167 err = evlist__mmap(evlist, opts.mmap_pages);
168 if (err < 0) {
169 pr_debug("evlist__mmap: %s\n",
170 str_error_r(errno, sbuf, sizeof(sbuf)));
171 goto out_delete_evlist;
172 }
173
174 evlist__enable(evlist);
175 (*func)();
176 evlist__disable(evlist);
177
178 for (i = 0; i < evlist->core.nr_mmaps; i++) {
179 union perf_event *event;
180 struct mmap *md;
181
182 md = &evlist->mmap[i];
183 if (perf_mmap__read_init(&md->core) < 0)
184 continue;
185
186 while ((event = perf_mmap__read_event(&md->core)) != NULL) {
187 const u32 type = event->header.type;
188
189 if (type == PERF_RECORD_SAMPLE)
190 count ++;
191 }
192 perf_mmap__read_done(&md->core);
193 }
194
195 if (count != expect * evlist->core.nr_entries) {
196 pr_debug("BPF filter result incorrect, expected %d, got %d samples\n", expect * evlist->core.nr_entries, count);
197 goto out_delete_evlist;
198 }
199
200 ret = TEST_OK;
201
202 out_delete_evlist:
203 evlist__delete(evlist);
204 return ret;
205 }
206
207 static struct bpf_object *
prepare_bpf(void * obj_buf,size_t obj_buf_sz,const char * name)208 prepare_bpf(void *obj_buf, size_t obj_buf_sz, const char *name)
209 {
210 struct bpf_object *obj;
211
212 obj = bpf__prepare_load_buffer(obj_buf, obj_buf_sz, name);
213 if (IS_ERR(obj)) {
214 pr_debug("Compile BPF program failed.\n");
215 return NULL;
216 }
217 return obj;
218 }
219
__test__bpf(int idx)220 static int __test__bpf(int idx)
221 {
222 int ret;
223 void *obj_buf;
224 size_t obj_buf_sz;
225 struct bpf_object *obj;
226
227 ret = test_llvm__fetch_bpf_obj(&obj_buf, &obj_buf_sz,
228 bpf_testcase_table[idx].prog_id,
229 false, NULL);
230 if (ret != TEST_OK || !obj_buf || !obj_buf_sz) {
231 pr_debug("Unable to get BPF object, %s\n",
232 bpf_testcase_table[idx].msg_compile_fail);
233 if ((idx == 0) || (ret == TEST_SKIP))
234 return TEST_SKIP;
235 else
236 return TEST_FAIL;
237 }
238
239 obj = prepare_bpf(obj_buf, obj_buf_sz,
240 bpf_testcase_table[idx].name);
241 if ((!!bpf_testcase_table[idx].target_func) != (!!obj)) {
242 if (!obj)
243 pr_debug("Fail to load BPF object: %s\n",
244 bpf_testcase_table[idx].msg_load_fail);
245 else
246 pr_debug("Success unexpectedly: %s\n",
247 bpf_testcase_table[idx].msg_load_fail);
248 ret = TEST_FAIL;
249 goto out;
250 }
251
252 if (obj) {
253 ret = do_test(obj,
254 bpf_testcase_table[idx].target_func,
255 bpf_testcase_table[idx].expect_result);
256 if (ret != TEST_OK)
257 goto out;
258 if (bpf_testcase_table[idx].pin) {
259 int err;
260
261 if (!bpf_fs__mount()) {
262 pr_debug("BPF filesystem not mounted\n");
263 ret = TEST_FAIL;
264 goto out;
265 }
266 err = mkdir(PERF_TEST_BPF_PATH, 0777);
267 if (err && errno != EEXIST) {
268 pr_debug("Failed to make perf_test dir: %s\n",
269 strerror(errno));
270 ret = TEST_FAIL;
271 goto out;
272 }
273 if (bpf_object__pin(obj, PERF_TEST_BPF_PATH))
274 ret = TEST_FAIL;
275 if (rm_rf(PERF_TEST_BPF_PATH))
276 ret = TEST_FAIL;
277 }
278 }
279
280 out:
281 free(obj_buf);
282 bpf__clear();
283 return ret;
284 }
285
check_env(void)286 static int check_env(void)
287 {
288 LIBBPF_OPTS(bpf_prog_load_opts, opts);
289 int err;
290 char license[] = "GPL";
291
292 struct bpf_insn insns[] = {
293 BPF_MOV64_IMM(BPF_REG_0, 1),
294 BPF_EXIT_INSN(),
295 };
296
297 err = fetch_kernel_version(&opts.kern_version, NULL, 0);
298 if (err) {
299 pr_debug("Unable to get kernel version\n");
300 return err;
301 }
302 err = bpf_prog_load(BPF_PROG_TYPE_KPROBE, NULL, license, insns,
303 ARRAY_SIZE(insns), &opts);
304 if (err < 0) {
305 pr_err("Missing basic BPF support, skip this test: %s\n",
306 strerror(errno));
307 return err;
308 }
309 close(err);
310
311 return 0;
312 }
313
test__bpf(int i)314 static int test__bpf(int i)
315 {
316 int err;
317
318 if (i < 0 || i >= (int)ARRAY_SIZE(bpf_testcase_table))
319 return TEST_FAIL;
320
321 if (geteuid() != 0) {
322 pr_debug("Only root can run BPF test\n");
323 return TEST_SKIP;
324 }
325
326 if (check_env())
327 return TEST_SKIP;
328
329 err = __test__bpf(i);
330 return err;
331 }
332 #endif
333
test__basic_bpf_test(struct test_suite * test __maybe_unused,int subtest __maybe_unused)334 static int test__basic_bpf_test(struct test_suite *test __maybe_unused,
335 int subtest __maybe_unused)
336 {
337 #if defined(HAVE_LIBBPF_SUPPORT) && defined(HAVE_LIBTRACEEVENT)
338 return test__bpf(0);
339 #else
340 pr_debug("Skip BPF test because BPF or libtraceevent support is not compiled\n");
341 return TEST_SKIP;
342 #endif
343 }
344
test__bpf_pinning(struct test_suite * test __maybe_unused,int subtest __maybe_unused)345 static int test__bpf_pinning(struct test_suite *test __maybe_unused,
346 int subtest __maybe_unused)
347 {
348 #if defined(HAVE_LIBBPF_SUPPORT) && defined(HAVE_LIBTRACEEVENT)
349 return test__bpf(1);
350 #else
351 pr_debug("Skip BPF test because BPF or libtraceevent support is not compiled\n");
352 return TEST_SKIP;
353 #endif
354 }
355
test__bpf_prologue_test(struct test_suite * test __maybe_unused,int subtest __maybe_unused)356 static int test__bpf_prologue_test(struct test_suite *test __maybe_unused,
357 int subtest __maybe_unused)
358 {
359 #if defined(HAVE_LIBBPF_SUPPORT) && defined(HAVE_BPF_PROLOGUE) && defined(HAVE_LIBTRACEEVENT)
360 return test__bpf(2);
361 #else
362 pr_debug("Skip BPF test because BPF or libtraceevent support is not compiled\n");
363 return TEST_SKIP;
364 #endif
365 }
366
367
368 static struct test_case bpf_tests[] = {
369 #if defined(HAVE_LIBBPF_SUPPORT) && defined(HAVE_LIBTRACEEVENT)
370 TEST_CASE("Basic BPF filtering", basic_bpf_test),
371 TEST_CASE_REASON("BPF pinning", bpf_pinning,
372 "clang isn't installed or environment missing BPF support"),
373 #ifdef HAVE_BPF_PROLOGUE
374 TEST_CASE_REASON("BPF prologue generation", bpf_prologue_test,
375 "clang/debuginfo isn't installed or environment missing BPF support"),
376 #else
377 TEST_CASE_REASON("BPF prologue generation", bpf_prologue_test, "not compiled in"),
378 #endif
379 #else
380 TEST_CASE_REASON("Basic BPF filtering", basic_bpf_test, "not compiled in or missing libtraceevent support"),
381 TEST_CASE_REASON("BPF pinning", bpf_pinning, "not compiled in or missing libtraceevent support"),
382 TEST_CASE_REASON("BPF prologue generation", bpf_prologue_test, "not compiled in or missing libtraceevent support"),
383 #endif
384 { .name = NULL, }
385 };
386
387 struct test_suite suite__bpf = {
388 .desc = "BPF filter",
389 .test_cases = bpf_tests,
390 };
391