1 // SPDX-License-Identifier: GPL-2.0
2 #include <errno.h>
3 #include <stdio.h>
4 #include <sys/epoll.h>
5 #include <sys/types.h>
6 #include <sys/stat.h>
7 #include <fcntl.h>
8 #include <util/record.h>
9 #include <util/util.h>
10 #include <util/bpf-loader.h>
11 #include <util/evlist.h>
12 #include <linux/bpf.h>
13 #include <linux/filter.h>
14 #include <linux/kernel.h>
15 #include <linux/string.h>
16 #include <api/fs/fs.h>
17 #include <bpf/bpf.h>
18 #include <perf/mmap.h>
19 #include "tests.h"
20 #include "llvm.h"
21 #include "debug.h"
22 #include "parse-events.h"
23 #include "util/mmap.h"
24 #define NR_ITERS 111
25 #define PERF_TEST_BPF_PATH "/sys/fs/bpf/perf_test"
26
27 #ifdef HAVE_LIBBPF_SUPPORT
28
epoll_pwait_loop(void)29 static int epoll_pwait_loop(void)
30 {
31 int i;
32
33 /* Should fail NR_ITERS times */
34 for (i = 0; i < NR_ITERS; i++)
35 epoll_pwait(-(i + 1), NULL, 0, 0, NULL);
36 return 0;
37 }
38
39 #ifdef HAVE_BPF_PROLOGUE
40
llseek_loop(void)41 static int llseek_loop(void)
42 {
43 int fds[2], i;
44
45 fds[0] = open("/dev/null", O_RDONLY);
46 fds[1] = open("/dev/null", O_RDWR);
47
48 if (fds[0] < 0 || fds[1] < 0)
49 return -1;
50
51 for (i = 0; i < NR_ITERS; i++) {
52 lseek(fds[i % 2], i, (i / 2) % 2 ? SEEK_CUR : SEEK_SET);
53 lseek(fds[(i + 1) % 2], i, (i / 2) % 2 ? SEEK_CUR : SEEK_SET);
54 }
55 close(fds[0]);
56 close(fds[1]);
57 return 0;
58 }
59
60 #endif
61
62 static struct {
63 enum test_llvm__testcase prog_id;
64 const char *desc;
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 .desc = "Basic BPF filtering",
75 .name = "[basic_bpf_test]",
76 .msg_compile_fail = "fix 'perf test LLVM' first",
77 .msg_load_fail = "load bpf object failed",
78 .target_func = &epoll_pwait_loop,
79 .expect_result = (NR_ITERS + 1) / 2,
80 },
81 {
82 .prog_id = LLVM_TESTCASE_BASE,
83 .desc = "BPF pinning",
84 .name = "[bpf_pinning]",
85 .msg_compile_fail = "fix kbuild first",
86 .msg_load_fail = "check your vmlinux setting?",
87 .target_func = &epoll_pwait_loop,
88 .expect_result = (NR_ITERS + 1) / 2,
89 .pin = true,
90 },
91 #ifdef HAVE_BPF_PROLOGUE
92 {
93 .prog_id = LLVM_TESTCASE_BPF_PROLOGUE,
94 .desc = "BPF prologue generation",
95 .name = "[bpf_prologue_test]",
96 .msg_compile_fail = "fix kbuild first",
97 .msg_load_fail = "check your vmlinux setting?",
98 .target_func = &llseek_loop,
99 .expect_result = (NR_ITERS + 1) / 4,
100 },
101 #endif
102 {
103 .prog_id = LLVM_TESTCASE_BPF_RELOCATION,
104 .desc = "BPF relocation checker",
105 .name = "[bpf_relocation_test]",
106 .msg_compile_fail = "fix 'perf test LLVM' first",
107 .msg_load_fail = "libbpf error when dealing with relocation",
108 },
109 };
110
do_test(struct bpf_object * obj,int (* func)(void),int expect)111 static int do_test(struct bpf_object *obj, int (*func)(void),
112 int expect)
113 {
114 struct record_opts opts = {
115 .target = {
116 .uid = UINT_MAX,
117 .uses_mmap = true,
118 },
119 .freq = 0,
120 .mmap_pages = 256,
121 .default_interval = 1,
122 };
123
124 char pid[16];
125 char sbuf[STRERR_BUFSIZE];
126 struct evlist *evlist;
127 int i, ret = TEST_FAIL, err = 0, count = 0;
128
129 struct parse_events_state parse_state;
130 struct parse_events_error parse_error;
131
132 bzero(&parse_error, sizeof(parse_error));
133 bzero(&parse_state, sizeof(parse_state));
134 parse_state.error = &parse_error;
135 INIT_LIST_HEAD(&parse_state.list);
136
137 err = parse_events_load_bpf_obj(&parse_state, &parse_state.list, obj, NULL);
138 if (err || list_empty(&parse_state.list)) {
139 pr_debug("Failed to add events selected by BPF\n");
140 return TEST_FAIL;
141 }
142
143 snprintf(pid, sizeof(pid), "%d", getpid());
144 pid[sizeof(pid) - 1] = '\0';
145 opts.target.tid = opts.target.pid = pid;
146
147 /* Instead of perf_evlist__new_default, don't add default events */
148 evlist = evlist__new();
149 if (!evlist) {
150 pr_debug("Not enough memory to create evlist\n");
151 return TEST_FAIL;
152 }
153
154 err = perf_evlist__create_maps(evlist, &opts.target);
155 if (err < 0) {
156 pr_debug("Not enough memory to create thread/cpu maps\n");
157 goto out_delete_evlist;
158 }
159
160 perf_evlist__splice_list_tail(evlist, &parse_state.list);
161 evlist->nr_groups = parse_state.nr_groups;
162
163 perf_evlist__config(evlist, &opts, NULL);
164
165 err = evlist__open(evlist);
166 if (err < 0) {
167 pr_debug("perf_evlist__open: %s\n",
168 str_error_r(errno, sbuf, sizeof(sbuf)));
169 goto out_delete_evlist;
170 }
171
172 err = evlist__mmap(evlist, opts.mmap_pages);
173 if (err < 0) {
174 pr_debug("evlist__mmap: %s\n",
175 str_error_r(errno, sbuf, sizeof(sbuf)));
176 goto out_delete_evlist;
177 }
178
179 evlist__enable(evlist);
180 (*func)();
181 evlist__disable(evlist);
182
183 for (i = 0; i < evlist->core.nr_mmaps; i++) {
184 union perf_event *event;
185 struct mmap *md;
186
187 md = &evlist->mmap[i];
188 if (perf_mmap__read_init(&md->core) < 0)
189 continue;
190
191 while ((event = perf_mmap__read_event(&md->core)) != NULL) {
192 const u32 type = event->header.type;
193
194 if (type == PERF_RECORD_SAMPLE)
195 count ++;
196 }
197 perf_mmap__read_done(&md->core);
198 }
199
200 if (count != expect * evlist->core.nr_entries) {
201 pr_debug("BPF filter result incorrect, expected %d, got %d samples\n", expect, count);
202 goto out_delete_evlist;
203 }
204
205 ret = TEST_OK;
206
207 out_delete_evlist:
208 evlist__delete(evlist);
209 return ret;
210 }
211
212 static struct bpf_object *
prepare_bpf(void * obj_buf,size_t obj_buf_sz,const char * name)213 prepare_bpf(void *obj_buf, size_t obj_buf_sz, const char *name)
214 {
215 struct bpf_object *obj;
216
217 obj = bpf__prepare_load_buffer(obj_buf, obj_buf_sz, name);
218 if (IS_ERR(obj)) {
219 pr_debug("Compile BPF program failed.\n");
220 return NULL;
221 }
222 return obj;
223 }
224
__test__bpf(int idx)225 static int __test__bpf(int idx)
226 {
227 int ret;
228 void *obj_buf;
229 size_t obj_buf_sz;
230 struct bpf_object *obj;
231
232 ret = test_llvm__fetch_bpf_obj(&obj_buf, &obj_buf_sz,
233 bpf_testcase_table[idx].prog_id,
234 true, NULL);
235 if (ret != TEST_OK || !obj_buf || !obj_buf_sz) {
236 pr_debug("Unable to get BPF object, %s\n",
237 bpf_testcase_table[idx].msg_compile_fail);
238 if (idx == 0)
239 return TEST_SKIP;
240 else
241 return TEST_FAIL;
242 }
243
244 obj = prepare_bpf(obj_buf, obj_buf_sz,
245 bpf_testcase_table[idx].name);
246 if ((!!bpf_testcase_table[idx].target_func) != (!!obj)) {
247 if (!obj)
248 pr_debug("Fail to load BPF object: %s\n",
249 bpf_testcase_table[idx].msg_load_fail);
250 else
251 pr_debug("Success unexpectedly: %s\n",
252 bpf_testcase_table[idx].msg_load_fail);
253 ret = TEST_FAIL;
254 goto out;
255 }
256
257 if (obj) {
258 ret = do_test(obj,
259 bpf_testcase_table[idx].target_func,
260 bpf_testcase_table[idx].expect_result);
261 if (ret != TEST_OK)
262 goto out;
263 if (bpf_testcase_table[idx].pin) {
264 int err;
265
266 if (!bpf_fs__mount()) {
267 pr_debug("BPF filesystem not mounted\n");
268 ret = TEST_FAIL;
269 goto out;
270 }
271 err = mkdir(PERF_TEST_BPF_PATH, 0777);
272 if (err && errno != EEXIST) {
273 pr_debug("Failed to make perf_test dir: %s\n",
274 strerror(errno));
275 ret = TEST_FAIL;
276 goto out;
277 }
278 if (bpf_object__pin(obj, PERF_TEST_BPF_PATH))
279 ret = TEST_FAIL;
280 if (rm_rf(PERF_TEST_BPF_PATH))
281 ret = TEST_FAIL;
282 }
283 }
284
285 out:
286 bpf__clear();
287 return ret;
288 }
289
test__bpf_subtest_get_nr(void)290 int test__bpf_subtest_get_nr(void)
291 {
292 return (int)ARRAY_SIZE(bpf_testcase_table);
293 }
294
test__bpf_subtest_get_desc(int i)295 const char *test__bpf_subtest_get_desc(int i)
296 {
297 if (i < 0 || i >= (int)ARRAY_SIZE(bpf_testcase_table))
298 return NULL;
299 return bpf_testcase_table[i].desc;
300 }
301
check_env(void)302 static int check_env(void)
303 {
304 int err;
305 unsigned int kver_int;
306 char license[] = "GPL";
307
308 struct bpf_insn insns[] = {
309 BPF_MOV64_IMM(BPF_REG_0, 1),
310 BPF_EXIT_INSN(),
311 };
312
313 err = fetch_kernel_version(&kver_int, NULL, 0);
314 if (err) {
315 pr_debug("Unable to get kernel version\n");
316 return err;
317 }
318
319 err = bpf_load_program(BPF_PROG_TYPE_KPROBE, insns,
320 sizeof(insns) / sizeof(insns[0]),
321 license, kver_int, NULL, 0);
322 if (err < 0) {
323 pr_err("Missing basic BPF support, skip this test: %s\n",
324 strerror(errno));
325 return err;
326 }
327 close(err);
328
329 return 0;
330 }
331
test__bpf(struct test * test __maybe_unused,int i)332 int test__bpf(struct test *test __maybe_unused, int i)
333 {
334 int err;
335
336 if (i < 0 || i >= (int)ARRAY_SIZE(bpf_testcase_table))
337 return TEST_FAIL;
338
339 if (geteuid() != 0) {
340 pr_debug("Only root can run BPF test\n");
341 return TEST_SKIP;
342 }
343
344 if (check_env())
345 return TEST_SKIP;
346
347 err = __test__bpf(i);
348 return err;
349 }
350
351 #else
test__bpf_subtest_get_nr(void)352 int test__bpf_subtest_get_nr(void)
353 {
354 return 0;
355 }
356
test__bpf_subtest_get_desc(int i __maybe_unused)357 const char *test__bpf_subtest_get_desc(int i __maybe_unused)
358 {
359 return NULL;
360 }
361
test__bpf(struct test * test __maybe_unused,int i __maybe_unused)362 int test__bpf(struct test *test __maybe_unused, int i __maybe_unused)
363 {
364 pr_debug("Skip BPF test because BPF support is not compiled\n");
365 return TEST_SKIP;
366 }
367 #endif
368