1 #include <errno.h>
2 #include <stdio.h>
3 #include <sys/epoll.h>
4 #include <sys/types.h>
5 #include <sys/stat.h>
6 #include <fcntl.h>
7 #include <util/util.h>
8 #include <util/bpf-loader.h>
9 #include <util/evlist.h>
10 #include <linux/bpf.h>
11 #include <linux/filter.h>
12 #include <linux/kernel.h>
13 #include <api/fs/fs.h>
14 #include <bpf/bpf.h>
15 #include "tests.h"
16 #include "llvm.h"
17 #include "debug.h"
18 #define NR_ITERS 111
19 #define PERF_TEST_BPF_PATH "/sys/fs/bpf/perf_test"
20
21 #ifdef HAVE_LIBBPF_SUPPORT
22
epoll_pwait_loop(void)23 static int epoll_pwait_loop(void)
24 {
25 int i;
26
27 /* Should fail NR_ITERS times */
28 for (i = 0; i < NR_ITERS; i++)
29 epoll_pwait(-(i + 1), NULL, 0, 0, NULL);
30 return 0;
31 }
32
33 #ifdef HAVE_BPF_PROLOGUE
34
llseek_loop(void)35 static int llseek_loop(void)
36 {
37 int fds[2], i;
38
39 fds[0] = open("/dev/null", O_RDONLY);
40 fds[1] = open("/dev/null", O_RDWR);
41
42 if (fds[0] < 0 || fds[1] < 0)
43 return -1;
44
45 for (i = 0; i < NR_ITERS; i++) {
46 lseek(fds[i % 2], i, (i / 2) % 2 ? SEEK_CUR : SEEK_SET);
47 lseek(fds[(i + 1) % 2], i, (i / 2) % 2 ? SEEK_CUR : SEEK_SET);
48 }
49 close(fds[0]);
50 close(fds[1]);
51 return 0;
52 }
53
54 #endif
55
56 static struct {
57 enum test_llvm__testcase prog_id;
58 const char *desc;
59 const char *name;
60 const char *msg_compile_fail;
61 const char *msg_load_fail;
62 int (*target_func)(void);
63 int expect_result;
64 bool pin;
65 } bpf_testcase_table[] = {
66 {
67 .prog_id = LLVM_TESTCASE_BASE,
68 .desc = "Basic BPF filtering",
69 .name = "[basic_bpf_test]",
70 .msg_compile_fail = "fix 'perf test LLVM' first",
71 .msg_load_fail = "load bpf object failed",
72 .target_func = &epoll_pwait_loop,
73 .expect_result = (NR_ITERS + 1) / 2,
74 },
75 {
76 .prog_id = LLVM_TESTCASE_BASE,
77 .desc = "BPF pinning",
78 .name = "[bpf_pinning]",
79 .msg_compile_fail = "fix kbuild first",
80 .msg_load_fail = "check your vmlinux setting?",
81 .target_func = &epoll_pwait_loop,
82 .expect_result = (NR_ITERS + 1) / 2,
83 .pin = true,
84 },
85 #ifdef HAVE_BPF_PROLOGUE
86 {
87 .prog_id = LLVM_TESTCASE_BPF_PROLOGUE,
88 .desc = "BPF prologue generation",
89 .name = "[bpf_prologue_test]",
90 .msg_compile_fail = "fix kbuild first",
91 .msg_load_fail = "check your vmlinux setting?",
92 .target_func = &llseek_loop,
93 .expect_result = (NR_ITERS + 1) / 4,
94 },
95 #endif
96 {
97 .prog_id = LLVM_TESTCASE_BPF_RELOCATION,
98 .desc = "BPF relocation checker",
99 .name = "[bpf_relocation_test]",
100 .msg_compile_fail = "fix 'perf test LLVM' first",
101 .msg_load_fail = "libbpf error when dealing with relocation",
102 },
103 };
104
do_test(struct bpf_object * obj,int (* func)(void),int expect)105 static int do_test(struct bpf_object *obj, int (*func)(void),
106 int expect)
107 {
108 struct record_opts opts = {
109 .target = {
110 .uid = UINT_MAX,
111 .uses_mmap = true,
112 },
113 .freq = 0,
114 .mmap_pages = 256,
115 .default_interval = 1,
116 };
117
118 char pid[16];
119 char sbuf[STRERR_BUFSIZE];
120 struct perf_evlist *evlist;
121 int i, ret = TEST_FAIL, err = 0, count = 0;
122
123 struct parse_events_state parse_state;
124 struct parse_events_error parse_error;
125
126 bzero(&parse_error, sizeof(parse_error));
127 bzero(&parse_state, sizeof(parse_state));
128 parse_state.error = &parse_error;
129 INIT_LIST_HEAD(&parse_state.list);
130
131 err = parse_events_load_bpf_obj(&parse_state, &parse_state.list, obj, NULL);
132 if (err || list_empty(&parse_state.list)) {
133 pr_debug("Failed to add events selected by BPF\n");
134 return TEST_FAIL;
135 }
136
137 snprintf(pid, sizeof(pid), "%d", getpid());
138 pid[sizeof(pid) - 1] = '\0';
139 opts.target.tid = opts.target.pid = pid;
140
141 /* Instead of perf_evlist__new_default, don't add default events */
142 evlist = perf_evlist__new();
143 if (!evlist) {
144 pr_debug("Not enough memory to create evlist\n");
145 return TEST_FAIL;
146 }
147
148 err = perf_evlist__create_maps(evlist, &opts.target);
149 if (err < 0) {
150 pr_debug("Not enough memory to create thread/cpu maps\n");
151 goto out_delete_evlist;
152 }
153
154 perf_evlist__splice_list_tail(evlist, &parse_state.list);
155 evlist->nr_groups = parse_state.nr_groups;
156
157 perf_evlist__config(evlist, &opts, NULL);
158
159 err = perf_evlist__open(evlist);
160 if (err < 0) {
161 pr_debug("perf_evlist__open: %s\n",
162 str_error_r(errno, sbuf, sizeof(sbuf)));
163 goto out_delete_evlist;
164 }
165
166 err = perf_evlist__mmap(evlist, opts.mmap_pages);
167 if (err < 0) {
168 pr_debug("perf_evlist__mmap: %s\n",
169 str_error_r(errno, sbuf, sizeof(sbuf)));
170 goto out_delete_evlist;
171 }
172
173 perf_evlist__enable(evlist);
174 (*func)();
175 perf_evlist__disable(evlist);
176
177 for (i = 0; i < evlist->nr_mmaps; i++) {
178 union perf_event *event;
179 struct perf_mmap *md;
180
181 md = &evlist->mmap[i];
182 if (perf_mmap__read_init(md) < 0)
183 continue;
184
185 while ((event = perf_mmap__read_event(md)) != NULL) {
186 const u32 type = event->header.type;
187
188 if (type == PERF_RECORD_SAMPLE)
189 count ++;
190 }
191 perf_mmap__read_done(md);
192 }
193
194 if (count != expect) {
195 pr_debug("BPF filter result incorrect, expected %d, got %d samples\n", expect, count);
196 goto out_delete_evlist;
197 }
198
199 ret = TEST_OK;
200
201 out_delete_evlist:
202 perf_evlist__delete(evlist);
203 return ret;
204 }
205
206 static struct bpf_object *
prepare_bpf(void * obj_buf,size_t obj_buf_sz,const char * name)207 prepare_bpf(void *obj_buf, size_t obj_buf_sz, const char *name)
208 {
209 struct bpf_object *obj;
210
211 obj = bpf__prepare_load_buffer(obj_buf, obj_buf_sz, name);
212 if (IS_ERR(obj)) {
213 pr_debug("Compile BPF program failed.\n");
214 return NULL;
215 }
216 return obj;
217 }
218
__test__bpf(int idx)219 static int __test__bpf(int idx)
220 {
221 int ret;
222 void *obj_buf;
223 size_t obj_buf_sz;
224 struct bpf_object *obj;
225
226 ret = test_llvm__fetch_bpf_obj(&obj_buf, &obj_buf_sz,
227 bpf_testcase_table[idx].prog_id,
228 true, NULL);
229 if (ret != TEST_OK || !obj_buf || !obj_buf_sz) {
230 pr_debug("Unable to get BPF object, %s\n",
231 bpf_testcase_table[idx].msg_compile_fail);
232 if (idx == 0)
233 return TEST_SKIP;
234 else
235 return TEST_FAIL;
236 }
237
238 obj = prepare_bpf(obj_buf, obj_buf_sz,
239 bpf_testcase_table[idx].name);
240 if ((!!bpf_testcase_table[idx].target_func) != (!!obj)) {
241 if (!obj)
242 pr_debug("Fail to load BPF object: %s\n",
243 bpf_testcase_table[idx].msg_load_fail);
244 else
245 pr_debug("Success unexpectedly: %s\n",
246 bpf_testcase_table[idx].msg_load_fail);
247 ret = TEST_FAIL;
248 goto out;
249 }
250
251 if (obj) {
252 ret = do_test(obj,
253 bpf_testcase_table[idx].target_func,
254 bpf_testcase_table[idx].expect_result);
255 if (ret != TEST_OK)
256 goto out;
257 if (bpf_testcase_table[idx].pin) {
258 int err;
259
260 if (!bpf_fs__mount()) {
261 pr_debug("BPF filesystem not mounted\n");
262 ret = TEST_FAIL;
263 goto out;
264 }
265 err = mkdir(PERF_TEST_BPF_PATH, 0777);
266 if (err && errno != EEXIST) {
267 pr_debug("Failed to make perf_test dir: %s\n",
268 strerror(errno));
269 ret = TEST_FAIL;
270 goto out;
271 }
272 if (bpf_object__pin(obj, PERF_TEST_BPF_PATH))
273 ret = TEST_FAIL;
274 if (rm_rf(PERF_TEST_BPF_PATH))
275 ret = TEST_FAIL;
276 }
277 }
278
279 out:
280 bpf__clear();
281 return ret;
282 }
283
test__bpf_subtest_get_nr(void)284 int test__bpf_subtest_get_nr(void)
285 {
286 return (int)ARRAY_SIZE(bpf_testcase_table);
287 }
288
test__bpf_subtest_get_desc(int i)289 const char *test__bpf_subtest_get_desc(int i)
290 {
291 if (i < 0 || i >= (int)ARRAY_SIZE(bpf_testcase_table))
292 return NULL;
293 return bpf_testcase_table[i].desc;
294 }
295
check_env(void)296 static int check_env(void)
297 {
298 int err;
299 unsigned int kver_int;
300 char license[] = "GPL";
301
302 struct bpf_insn insns[] = {
303 BPF_MOV64_IMM(BPF_REG_0, 1),
304 BPF_EXIT_INSN(),
305 };
306
307 err = fetch_kernel_version(&kver_int, NULL, 0);
308 if (err) {
309 pr_debug("Unable to get kernel version\n");
310 return err;
311 }
312
313 err = bpf_load_program(BPF_PROG_TYPE_KPROBE, insns,
314 sizeof(insns) / sizeof(insns[0]),
315 license, kver_int, NULL, 0);
316 if (err < 0) {
317 pr_err("Missing basic BPF support, skip this test: %s\n",
318 strerror(errno));
319 return err;
320 }
321 close(err);
322
323 return 0;
324 }
325
test__bpf(struct test * test __maybe_unused,int i)326 int test__bpf(struct test *test __maybe_unused, int i)
327 {
328 int err;
329
330 if (i < 0 || i >= (int)ARRAY_SIZE(bpf_testcase_table))
331 return TEST_FAIL;
332
333 if (geteuid() != 0) {
334 pr_debug("Only root can run BPF test\n");
335 return TEST_SKIP;
336 }
337
338 if (check_env())
339 return TEST_SKIP;
340
341 err = __test__bpf(i);
342 return err;
343 }
344
345 #else
test__bpf_subtest_get_nr(void)346 int test__bpf_subtest_get_nr(void)
347 {
348 return 0;
349 }
350
test__bpf_subtest_get_desc(int i __maybe_unused)351 const char *test__bpf_subtest_get_desc(int i __maybe_unused)
352 {
353 return NULL;
354 }
355
test__bpf(struct test * test __maybe_unused,int i __maybe_unused)356 int test__bpf(struct test *test __maybe_unused, int i __maybe_unused)
357 {
358 pr_debug("Skip BPF test because BPF support is not compiled\n");
359 return TEST_SKIP;
360 }
361 #endif
362
