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 #ifdef HAVE_LIBBPF_SUPPORT
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 || list_empty(&parse_state.list)) {
130 pr_debug("Failed to add events selected by BPF\n");
131 return TEST_FAIL;
132 }
133
134 snprintf(pid, sizeof(pid), "%d", getpid());
135 pid[sizeof(pid) - 1] = '\0';
136 opts.target.tid = opts.target.pid = pid;
137
138 /* Instead of evlist__new_default, don't add default events */
139 evlist = evlist__new();
140 if (!evlist) {
141 pr_debug("Not enough memory to create evlist\n");
142 return TEST_FAIL;
143 }
144
145 err = evlist__create_maps(evlist, &opts.target);
146 if (err < 0) {
147 pr_debug("Not enough memory to create thread/cpu maps\n");
148 goto out_delete_evlist;
149 }
150
151 evlist__splice_list_tail(evlist, &parse_state.list);
152 evlist->core.nr_groups = parse_state.nr_groups;
153
154 evlist__config(evlist, &opts, NULL);
155
156 err = evlist__open(evlist);
157 if (err < 0) {
158 pr_debug("perf_evlist__open: %s\n",
159 str_error_r(errno, sbuf, sizeof(sbuf)));
160 goto out_delete_evlist;
161 }
162
163 err = evlist__mmap(evlist, opts.mmap_pages);
164 if (err < 0) {
165 pr_debug("evlist__mmap: %s\n",
166 str_error_r(errno, sbuf, sizeof(sbuf)));
167 goto out_delete_evlist;
168 }
169
170 evlist__enable(evlist);
171 (*func)();
172 evlist__disable(evlist);
173
174 for (i = 0; i < evlist->core.nr_mmaps; i++) {
175 union perf_event *event;
176 struct mmap *md;
177
178 md = &evlist->mmap[i];
179 if (perf_mmap__read_init(&md->core) < 0)
180 continue;
181
182 while ((event = perf_mmap__read_event(&md->core)) != NULL) {
183 const u32 type = event->header.type;
184
185 if (type == PERF_RECORD_SAMPLE)
186 count ++;
187 }
188 perf_mmap__read_done(&md->core);
189 }
190
191 if (count != expect * evlist->core.nr_entries) {
192 pr_debug("BPF filter result incorrect, expected %d, got %d samples\n", expect * evlist->core.nr_entries, count);
193 goto out_delete_evlist;
194 }
195
196 ret = TEST_OK;
197
198 out_delete_evlist:
199 evlist__delete(evlist);
200 return ret;
201 }
202
203 static struct bpf_object *
prepare_bpf(void * obj_buf,size_t obj_buf_sz,const char * name)204 prepare_bpf(void *obj_buf, size_t obj_buf_sz, const char *name)
205 {
206 struct bpf_object *obj;
207
208 obj = bpf__prepare_load_buffer(obj_buf, obj_buf_sz, name);
209 if (IS_ERR(obj)) {
210 pr_debug("Compile BPF program failed.\n");
211 return NULL;
212 }
213 return obj;
214 }
215
__test__bpf(int idx)216 static int __test__bpf(int idx)
217 {
218 int ret;
219 void *obj_buf;
220 size_t obj_buf_sz;
221 struct bpf_object *obj;
222
223 ret = test_llvm__fetch_bpf_obj(&obj_buf, &obj_buf_sz,
224 bpf_testcase_table[idx].prog_id,
225 true, NULL);
226 if (ret != TEST_OK || !obj_buf || !obj_buf_sz) {
227 pr_debug("Unable to get BPF object, %s\n",
228 bpf_testcase_table[idx].msg_compile_fail);
229 if (idx == 0)
230 return TEST_SKIP;
231 else
232 return TEST_FAIL;
233 }
234
235 obj = prepare_bpf(obj_buf, obj_buf_sz,
236 bpf_testcase_table[idx].name);
237 if ((!!bpf_testcase_table[idx].target_func) != (!!obj)) {
238 if (!obj)
239 pr_debug("Fail to load BPF object: %s\n",
240 bpf_testcase_table[idx].msg_load_fail);
241 else
242 pr_debug("Success unexpectedly: %s\n",
243 bpf_testcase_table[idx].msg_load_fail);
244 ret = TEST_FAIL;
245 goto out;
246 }
247
248 if (obj) {
249 ret = do_test(obj,
250 bpf_testcase_table[idx].target_func,
251 bpf_testcase_table[idx].expect_result);
252 if (ret != TEST_OK)
253 goto out;
254 if (bpf_testcase_table[idx].pin) {
255 int err;
256
257 if (!bpf_fs__mount()) {
258 pr_debug("BPF filesystem not mounted\n");
259 ret = TEST_FAIL;
260 goto out;
261 }
262 err = mkdir(PERF_TEST_BPF_PATH, 0777);
263 if (err && errno != EEXIST) {
264 pr_debug("Failed to make perf_test dir: %s\n",
265 strerror(errno));
266 ret = TEST_FAIL;
267 goto out;
268 }
269 if (bpf_object__pin(obj, PERF_TEST_BPF_PATH))
270 ret = TEST_FAIL;
271 if (rm_rf(PERF_TEST_BPF_PATH))
272 ret = TEST_FAIL;
273 }
274 }
275
276 out:
277 free(obj_buf);
278 bpf__clear();
279 return ret;
280 }
281
check_env(void)282 static int check_env(void)
283 {
284 int err;
285 unsigned int kver_int;
286 char license[] = "GPL";
287
288 struct bpf_insn insns[] = {
289 BPF_MOV64_IMM(BPF_REG_0, 1),
290 BPF_EXIT_INSN(),
291 };
292
293 err = fetch_kernel_version(&kver_int, NULL, 0);
294 if (err) {
295 pr_debug("Unable to get kernel version\n");
296 return err;
297 }
298
299 err = bpf_load_program(BPF_PROG_TYPE_KPROBE, insns,
300 ARRAY_SIZE(insns),
301 license, kver_int, NULL, 0);
302 if (err < 0) {
303 pr_err("Missing basic BPF support, skip this test: %s\n",
304 strerror(errno));
305 return err;
306 }
307 close(err);
308
309 return 0;
310 }
311
test__bpf(int i)312 static int test__bpf(int i)
313 {
314 int err;
315
316 if (i < 0 || i >= (int)ARRAY_SIZE(bpf_testcase_table))
317 return TEST_FAIL;
318
319 if (geteuid() != 0) {
320 pr_debug("Only root can run BPF test\n");
321 return TEST_SKIP;
322 }
323
324 if (check_env())
325 return TEST_SKIP;
326
327 err = __test__bpf(i);
328 return err;
329 }
330 #endif
331
test__basic_bpf_test(struct test_suite * test __maybe_unused,int subtest __maybe_unused)332 static int test__basic_bpf_test(struct test_suite *test __maybe_unused,
333 int subtest __maybe_unused)
334 {
335 #ifdef HAVE_LIBBPF_SUPPORT
336 return test__bpf(0);
337 #else
338 pr_debug("Skip BPF test because BPF support is not compiled\n");
339 return TEST_SKIP;
340 #endif
341 }
342
test__bpf_pinning(struct test_suite * test __maybe_unused,int subtest __maybe_unused)343 static int test__bpf_pinning(struct test_suite *test __maybe_unused,
344 int subtest __maybe_unused)
345 {
346 #ifdef HAVE_LIBBPF_SUPPORT
347 return test__bpf(1);
348 #else
349 pr_debug("Skip BPF test because BPF support is not compiled\n");
350 return TEST_SKIP;
351 #endif
352 }
353
test__bpf_prologue_test(struct test_suite * test __maybe_unused,int subtest __maybe_unused)354 static int test__bpf_prologue_test(struct test_suite *test __maybe_unused,
355 int subtest __maybe_unused)
356 {
357 #if defined(HAVE_LIBBPF_SUPPORT) && defined(HAVE_BPF_PROLOGUE)
358 return test__bpf(2);
359 #else
360 pr_debug("Skip BPF test because BPF support is not compiled\n");
361 return TEST_SKIP;
362 #endif
363 }
364
365
366 static struct test_case bpf_tests[] = {
367 #ifdef HAVE_LIBBPF_SUPPORT
368 TEST_CASE("Basic BPF filtering", basic_bpf_test),
369 TEST_CASE("BPF pinning", bpf_pinning),
370 #ifdef HAVE_BPF_PROLOGUE
371 TEST_CASE("BPF prologue generation", bpf_prologue_test),
372 #else
373 TEST_CASE_REASON("BPF prologue generation", bpf_prologue_test, "not compiled in"),
374 #endif
375 #else
376 TEST_CASE_REASON("Basic BPF filtering", basic_bpf_test, "not compiled in"),
377 TEST_CASE_REASON("BPF pinning", bpf_pinning, "not compiled in"),
378 TEST_CASE_REASON("BPF prologue generation", bpf_prologue_test, "not compiled in"),
379 #endif
380 { .name = NULL, }
381 };
382
383 struct test_suite suite__bpf = {
384 .desc = "BPF filter",
385 .test_cases = bpf_tests,
386 };
387