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  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
 29static 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
 41static 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
 62static 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
111static 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
207out_delete_evlist:
208	evlist__delete(evlist);
209	return ret;
210}
211
212static struct bpf_object *
213prepare_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
225static 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
285out:
286	bpf__clear();
287	return ret;
288}
289
290int test__bpf_subtest_get_nr(void)
291{
292	return (int)ARRAY_SIZE(bpf_testcase_table);
293}
294
295const 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
302static 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
332int 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
352int test__bpf_subtest_get_nr(void)
353{
354	return 0;
355}
356
357const char *test__bpf_subtest_get_desc(int i __maybe_unused)
358{
359	return NULL;
360}
361
362int 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