[linux.git] / samples / bpf / task_fd_query_user.c

// SPDX-License-Identifier: GPL-2.0

#include <stdio.h>
#include <stdlib.h>
#include <signal.h>
#include <unistd.h>
#include <stdbool.h>
#include <string.h>
#include <stdint.h>
#include <fcntl.h>
#include <linux/bpf.h>
#include <sys/ioctl.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <linux/perf_event.h>

#include <bpf/bpf.h>
#include <bpf/libbpf.h>
#include "bpf_util.h"
#include "perf-sys.h"
#include "trace_helpers.h"

static struct bpf_program *progs[2];
static struct bpf_link *links[2];

#define CHECK_PERROR_RET(condition) ({			\
	int __ret = !!(condition);			\
	if (__ret) {					\
		printf("FAIL: %s:\n", __func__);	\
		perror("    ");			\
		return -1;				\
	}						\
})

#define CHECK_AND_RET(condition) ({			\
	int __ret = !!(condition);			\
	if (__ret)					\
		return -1;				\
})

static __u64 ptr_to_u64(void *ptr)
{
	return (__u64) (unsigned long) ptr;
}

#define PMU_TYPE_FILE "/sys/bus/event_source/devices/%s/type"
static int bpf_find_probe_type(const char *event_type)
{
	char buf[256];
	int fd, ret;

	ret = snprintf(buf, sizeof(buf), PMU_TYPE_FILE, event_type);
	CHECK_PERROR_RET(ret < 0 || ret >= sizeof(buf));

	fd = open(buf, O_RDONLY);
	CHECK_PERROR_RET(fd < 0);

	ret = read(fd, buf, sizeof(buf));
	close(fd);
	CHECK_PERROR_RET(ret < 0 || ret >= sizeof(buf));

	errno = 0;
	ret = (int)strtol(buf, NULL, 10);
	CHECK_PERROR_RET(errno);
	return ret;
}

#define PMU_RETPROBE_FILE "/sys/bus/event_source/devices/%s/format/retprobe"
static int bpf_get_retprobe_bit(const char *event_type)
{
	char buf[256];
	int fd, ret;

	ret = snprintf(buf, sizeof(buf), PMU_RETPROBE_FILE, event_type);
	CHECK_PERROR_RET(ret < 0 || ret >= sizeof(buf));

	fd = open(buf, O_RDONLY);
	CHECK_PERROR_RET(fd < 0);

	ret = read(fd, buf, sizeof(buf));
	close(fd);
	CHECK_PERROR_RET(ret < 0 || ret >= sizeof(buf));
	CHECK_PERROR_RET(strlen(buf) < strlen("config:"));

	errno = 0;
	ret = (int)strtol(buf + strlen("config:"), NULL, 10);
	CHECK_PERROR_RET(errno);
	return ret;
}

static int test_debug_fs_kprobe(int link_idx, const char *fn_name,
				__u32 expected_fd_type)
{
	__u64 probe_offset, probe_addr;
	__u32 len, prog_id, fd_type;
	int err, event_fd;
	char buf[256];

	len = sizeof(buf);
	event_fd = bpf_link__fd(links[link_idx]);
	err = bpf_task_fd_query(getpid(), event_fd, 0, buf, &len,
				&prog_id, &fd_type, &probe_offset,
				&probe_addr);
	if (err < 0) {
		printf("FAIL: %s, for event_fd idx %d, fn_name %s\n",
		       __func__, link_idx, fn_name);
		perror("    :");
		return -1;
	}
	if (strcmp(buf, fn_name) != 0 ||
	    fd_type != expected_fd_type ||
	    probe_offset != 0x0 || probe_addr != 0x0) {
		printf("FAIL: bpf_trace_event_query(event_fd[%d]):\n",
		       link_idx);
		printf("buf: %s, fd_type: %u, probe_offset: 0x%llx,"
		       " probe_addr: 0x%llx\n",
		       buf, fd_type, probe_offset, probe_addr);
		return -1;
	}
	return 0;
}

static int test_nondebug_fs_kuprobe_common(const char *event_type,
	const char *name, __u64 offset, __u64 addr, bool is_return,
	char *buf, __u32 *buf_len, __u32 *prog_id, __u32 *fd_type,
	__u64 *probe_offset, __u64 *probe_addr)
{
	int is_return_bit = bpf_get_retprobe_bit(event_type);
	int type = bpf_find_probe_type(event_type);
	struct perf_event_attr attr = {};
	struct bpf_link *link;
	int fd, err = -1;

	if (type < 0 || is_return_bit < 0) {
		printf("FAIL: %s incorrect type (%d) or is_return_bit (%d)\n",
			__func__, type, is_return_bit);
		return err;
	}

	attr.sample_period = 1;
	attr.wakeup_events = 1;
	if (is_return)
		attr.config |= 1 << is_return_bit;

	if (name) {
		attr.config1 = ptr_to_u64((void *)name);
		attr.config2 = offset;
	} else {
		attr.config1 = 0;
		attr.config2 = addr;
	}
	attr.size = sizeof(attr);
	attr.type = type;

	fd = sys_perf_event_open(&attr, -1, 0, -1, 0);
	link = bpf_program__attach_perf_event(progs[0], fd);
	if (libbpf_get_error(link)) {
		printf("ERROR: bpf_program__attach_perf_event failed\n");
		link = NULL;
		close(fd);
		goto cleanup;
	}

	CHECK_PERROR_RET(bpf_task_fd_query(getpid(), fd, 0, buf, buf_len,
			 prog_id, fd_type, probe_offset, probe_addr) < 0);
	err = 0;

cleanup:
	bpf_link__destroy(link);
	return err;
}

static int test_nondebug_fs_probe(const char *event_type, const char *name,
				  __u64 offset, __u64 addr, bool is_return,
				  __u32 expected_fd_type,
				  __u32 expected_ret_fd_type,
				  char *buf, __u32 buf_len)
{
	__u64 probe_offset, probe_addr;
	__u32 prog_id, fd_type;
	int err;

	err = test_nondebug_fs_kuprobe_common(event_type, name,
					      offset, addr, is_return,
					      buf, &buf_len, &prog_id,
					      &fd_type, &probe_offset,
					      &probe_addr);
	if (err < 0) {
		printf("FAIL: %s, "
		       "for name %s, offset 0x%llx, addr 0x%llx, is_return %d\n",
		       __func__, name ? name : "", offset, addr, is_return);
		perror("    :");
		return -1;
	}
	if ((is_return && fd_type != expected_ret_fd_type) ||
	    (!is_return && fd_type != expected_fd_type)) {
		printf("FAIL: %s, incorrect fd_type %u\n",
		       __func__, fd_type);
		return -1;
	}
	if (name) {
		if (strcmp(name, buf) != 0) {
			printf("FAIL: %s, incorrect buf %s\n", __func__, buf);
			return -1;
		}
		if (probe_offset != offset) {
			printf("FAIL: %s, incorrect probe_offset 0x%llx\n",
			       __func__, probe_offset);
			return -1;
		}
	} else {
		if (buf_len != 0) {
			printf("FAIL: %s, incorrect buf %p\n",
			       __func__, buf);
			return -1;
		}

		if (probe_addr != addr) {
			printf("FAIL: %s, incorrect probe_addr 0x%llx\n",
			       __func__, probe_addr);
			return -1;
		}
	}
	return 0;
}

static int test_debug_fs_uprobe(char *binary_path, long offset, bool is_return)
{
	char buf[256], event_alias[sizeof("test_1234567890")];
	const char *event_type = "uprobe";
	struct perf_event_attr attr = {};
	__u64 probe_offset, probe_addr;
	__u32 len, prog_id, fd_type;
	int err = -1, res, kfd, efd;
	struct bpf_link *link;
	ssize_t bytes;

	snprintf(buf, sizeof(buf), "/sys/kernel/debug/tracing/%s_events",
		 event_type);
	kfd = open(buf, O_WRONLY | O_TRUNC, 0);
	CHECK_PERROR_RET(kfd < 0);

	res = snprintf(event_alias, sizeof(event_alias), "test_%d", getpid());
	CHECK_PERROR_RET(res < 0 || res >= sizeof(event_alias));

	res = snprintf(buf, sizeof(buf), "%c:%ss/%s %s:0x%lx",
		       is_return ? 'r' : 'p', event_type, event_alias,
		       binary_path, offset);
	CHECK_PERROR_RET(res < 0 || res >= sizeof(buf));
	CHECK_PERROR_RET(write(kfd, buf, strlen(buf)) < 0);

	close(kfd);
	kfd = -1;

	snprintf(buf, sizeof(buf), "/sys/kernel/debug/tracing/events/%ss/%s/id",
		 event_type, event_alias);
	efd = open(buf, O_RDONLY, 0);
	CHECK_PERROR_RET(efd < 0);

	bytes = read(efd, buf, sizeof(buf));
	CHECK_PERROR_RET(bytes <= 0 || bytes >= sizeof(buf));
	close(efd);
	buf[bytes] = '\0';

	attr.config = strtol(buf, NULL, 0);
	attr.type = PERF_TYPE_TRACEPOINT;
	attr.sample_period = 1;
	attr.wakeup_events = 1;

	kfd = sys_perf_event_open(&attr, -1, 0, -1, PERF_FLAG_FD_CLOEXEC);
	link = bpf_program__attach_perf_event(progs[0], kfd);
	if (libbpf_get_error(link)) {
		printf("ERROR: bpf_program__attach_perf_event failed\n");
		link = NULL;
		close(kfd);
		goto cleanup;
	}

	len = sizeof(buf);
	err = bpf_task_fd_query(getpid(), kfd, 0, buf, &len,
				&prog_id, &fd_type, &probe_offset,
				&probe_addr);
	if (err < 0) {
		printf("FAIL: %s, binary_path %s\n", __func__, binary_path);
		perror("    :");
		return -1;
	}
	if ((is_return && fd_type != BPF_FD_TYPE_URETPROBE) ||
	    (!is_return && fd_type != BPF_FD_TYPE_UPROBE)) {
		printf("FAIL: %s, incorrect fd_type %u\n", __func__,
		       fd_type);
		return -1;
	}
	if (strcmp(binary_path, buf) != 0) {
		printf("FAIL: %s, incorrect buf %s\n", __func__, buf);
		return -1;
	}
	if (probe_offset != offset) {
		printf("FAIL: %s, incorrect probe_offset 0x%llx\n", __func__,
		       probe_offset);
		return -1;
	}
	err = 0;

cleanup:
	bpf_link__destroy(link);
	return err;
}

int main(int argc, char **argv)
{
	extern char __executable_start;
	char filename[256], buf[256];
	__u64 uprobe_file_offset;
	struct bpf_program *prog;
	struct bpf_object *obj;
	int i = 0, err = -1;

	if (load_kallsyms()) {
		printf("failed to process /proc/kallsyms\n");
		return err;
	}

	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
	obj = bpf_object__open_file(filename, NULL);
	if (libbpf_get_error(obj)) {
		fprintf(stderr, "ERROR: opening BPF object file failed\n");
		return err;
	}

	/* load BPF program */
	if (bpf_object__load(obj)) {
		fprintf(stderr, "ERROR: loading BPF object file failed\n");
		goto cleanup;
	}

	bpf_object__for_each_program(prog, obj) {
		progs[i] = prog;
		links[i] = bpf_program__attach(progs[i]);
		if (libbpf_get_error(links[i])) {
			fprintf(stderr, "ERROR: bpf_program__attach failed\n");
			links[i] = NULL;
			goto cleanup;
		}
		i++;
	}

	/* test two functions in the corresponding *_kern.c file */
	CHECK_AND_RET(test_debug_fs_kprobe(0, "blk_mq_start_request",
					   BPF_FD_TYPE_KPROBE));
	CHECK_AND_RET(test_debug_fs_kprobe(1, "__blk_account_io_done",
					   BPF_FD_TYPE_KRETPROBE));

	/* test nondebug fs kprobe */
	CHECK_AND_RET(test_nondebug_fs_probe("kprobe", "bpf_check", 0x0, 0x0,
					     false, BPF_FD_TYPE_KPROBE,
					     BPF_FD_TYPE_KRETPROBE,
					     buf, sizeof(buf)));
#ifdef __x86_64__
	/* set a kprobe on "bpf_check + 0x5", which is x64 specific */
	CHECK_AND_RET(test_nondebug_fs_probe("kprobe", "bpf_check", 0x5, 0x0,
					     false, BPF_FD_TYPE_KPROBE,
					     BPF_FD_TYPE_KRETPROBE,
					     buf, sizeof(buf)));
#endif
	CHECK_AND_RET(test_nondebug_fs_probe("kprobe", "bpf_check", 0x0, 0x0,
					     true, BPF_FD_TYPE_KPROBE,
					     BPF_FD_TYPE_KRETPROBE,
					     buf, sizeof(buf)));
	CHECK_AND_RET(test_nondebug_fs_probe("kprobe", NULL, 0x0,
					     ksym_get_addr("bpf_check"), false,
					     BPF_FD_TYPE_KPROBE,
					     BPF_FD_TYPE_KRETPROBE,
					     buf, sizeof(buf)));
	CHECK_AND_RET(test_nondebug_fs_probe("kprobe", NULL, 0x0,
					     ksym_get_addr("bpf_check"), false,
					     BPF_FD_TYPE_KPROBE,
					     BPF_FD_TYPE_KRETPROBE,
					     NULL, 0));
	CHECK_AND_RET(test_nondebug_fs_probe("kprobe", NULL, 0x0,
					     ksym_get_addr("bpf_check"), true,
					     BPF_FD_TYPE_KPROBE,
					     BPF_FD_TYPE_KRETPROBE,
					     buf, sizeof(buf)));
	CHECK_AND_RET(test_nondebug_fs_probe("kprobe", NULL, 0x0,
					     ksym_get_addr("bpf_check"), true,
					     BPF_FD_TYPE_KPROBE,
					     BPF_FD_TYPE_KRETPROBE,
					     0, 0));

	/* test nondebug fs uprobe */
	/* the calculation of uprobe file offset is based on gcc 7.3.1 on x64
	 * and the default linker script, which defines __executable_start as
	 * the start of the .text section. The calculation could be different
	 * on different systems with different compilers. The right way is
	 * to parse the ELF file. We took a shortcut here.
	 */
	uprobe_file_offset = (unsigned long)main - (unsigned long)&__executable_start;
	CHECK_AND_RET(test_nondebug_fs_probe("uprobe", (char *)argv[0],
					     uprobe_file_offset, 0x0, false,
					     BPF_FD_TYPE_UPROBE,
					     BPF_FD_TYPE_URETPROBE,
					     buf, sizeof(buf)));
	CHECK_AND_RET(test_nondebug_fs_probe("uprobe", (char *)argv[0],
					     uprobe_file_offset, 0x0, true,
					     BPF_FD_TYPE_UPROBE,
					     BPF_FD_TYPE_URETPROBE,
					     buf, sizeof(buf)));

	/* test debug fs uprobe */
	CHECK_AND_RET(test_debug_fs_uprobe((char *)argv[0], uprobe_file_offset,
					   false));
	CHECK_AND_RET(test_debug_fs_uprobe((char *)argv[0], uprobe_file_offset,
					   true));
	err = 0;

cleanup:
	for (i--; i >= 0; i--)
		bpf_link__destroy(links[i]);

	bpf_object__close(obj);
	return err;
}
Commit	Line	Data
ecb96f7f YS	1	// SPDX-License-Identifier: GPL-2.0
	2
	3	#include <stdio.h>
	4	#include <stdlib.h>
	5	#include <signal.h>
	6	#include <unistd.h>
	7	#include <stdbool.h>
	8	#include <string.h>
	9	#include <stdint.h>
	10	#include <fcntl.h>
	11	#include <linux/bpf.h>
	12	#include <sys/ioctl.h>
ecb96f7f YS	13	#include <sys/types.h>
ecb96f7f YS	14	#include <sys/stat.h>
e55190f2	15	#include <linux/perf_event.h>
ecb96f7f	16
4fe66415	17	#include <bpf/bpf.h>
7cf245a3	18	#include <bpf/libbpf.h>
ecb96f7f YS	19	#include "bpf_util.h"
	20	#include "perf-sys.h"
	21	#include "trace_helpers.h"
	22
4fe66415 DL	23	static struct bpf_program *progs[2];
	24	static struct bpf_link *links[2];
	25
ecb96f7f YS	26	#define CHECK_PERROR_RET(condition) ({ \
	27	int __ret = !!(condition); \
	28	if (__ret) { \
	29	printf("FAIL: %s:\n", __func__); \
	30	perror(" "); \
	31	return -1; \
	32	} \
	33	})
	34
	35	#define CHECK_AND_RET(condition) ({ \
	36	int __ret = !!(condition); \
	37	if (__ret) \
	38	return -1; \
	39	})
	40
	41	static __u64 ptr_to_u64(void *ptr)
	42	{
	43	return (__u64) (unsigned long) ptr;
	44	}
	45
	46	#define PMU_TYPE_FILE "/sys/bus/event_source/devices/%s/type"
	47	static int bpf_find_probe_type(const char *event_type)
	48	{
	49	char buf[256];
	50	int fd, ret;
	51
	52	ret = snprintf(buf, sizeof(buf), PMU_TYPE_FILE, event_type);
	53	CHECK_PERROR_RET(ret < 0 \|\| ret >= sizeof(buf));
	54
	55	fd = open(buf, O_RDONLY);
	56	CHECK_PERROR_RET(fd < 0);
	57
	58	ret = read(fd, buf, sizeof(buf));
	59	close(fd);
	60	CHECK_PERROR_RET(ret < 0 \|\| ret >= sizeof(buf));
	61
	62	errno = 0;
	63	ret = (int)strtol(buf, NULL, 10);
	64	CHECK_PERROR_RET(errno);
	65	return ret;
	66	}
	67
	68	#define PMU_RETPROBE_FILE "/sys/bus/event_source/devices/%s/format/retprobe"
	69	static int bpf_get_retprobe_bit(const char *event_type)
	70	{
	71	char buf[256];
	72	int fd, ret;
	73
	74	ret = snprintf(buf, sizeof(buf), PMU_RETPROBE_FILE, event_type);
	75	CHECK_PERROR_RET(ret < 0 \|\| ret >= sizeof(buf));
	76
	77	fd = open(buf, O_RDONLY);
	78	CHECK_PERROR_RET(fd < 0);
	79
	80	ret = read(fd, buf, sizeof(buf));
	81	close(fd);
	82	CHECK_PERROR_RET(ret < 0 \|\| ret >= sizeof(buf));
	83	CHECK_PERROR_RET(strlen(buf) < strlen("config:"));
	84
	85	errno = 0;
	86	ret = (int)strtol(buf + strlen("config:"), NULL, 10);
	87	CHECK_PERROR_RET(errno);
	88	return ret;
	89	}
90
4fe66415	91	static int test_debug_fs_kprobe(int link_idx, const char *fn_name,
ecb96f7f YS	92	__u32 expected_fd_type)
	93	{
	94	__u64 probe_offset, probe_addr;
	95	__u32 len, prog_id, fd_type;
4fe66415	96	int err, event_fd;
ecb96f7f	97	char buf[256];
ecb96f7f YS	98
ecb96f7f YS	99	len = sizeof(buf);
4fe66415 DL	100	event_fd = bpf_link__fd(links[link_idx]);
4fe66415 DL	101	err = bpf_task_fd_query(getpid(), event_fd, 0, buf, &len,
ecb96f7f YS	102	&prog_id, &fd_type, &probe_offset,
	103	&probe_addr);
	104	if (err < 0) {
	105	printf("FAIL: %s, for event_fd idx %d, fn_name %s\n",
4fe66415	106	__func__, link_idx, fn_name);
ecb96f7f YS	107	perror(" :");
	108	return -1;
	109	}
	110	if (strcmp(buf, fn_name) != 0 \|\|
	111	fd_type != expected_fd_type \|\|
	112	probe_offset != 0x0 \|\| probe_addr != 0x0) {
	113	printf("FAIL: bpf_trace_event_query(event_fd[%d]):\n",
4fe66415	114	link_idx);
ecb96f7f YS	115	printf("buf: %s, fd_type: %u, probe_offset: 0x%llx,"
	116	" probe_addr: 0x%llx\n",
	117	buf, fd_type, probe_offset, probe_addr);
	118	return -1;
	119	}
	120	return 0;
	121	}
	122
	123	static int test_nondebug_fs_kuprobe_common(const char *event_type,
	124	const char *name, __u64 offset, __u64 addr, bool is_return,
	125	char buf, __u32 buf_len, __u32 prog_id, __u32 fd_type,
	126	__u64 probe_offset, __u64 probe_addr)
	127	{
	128	int is_return_bit = bpf_get_retprobe_bit(event_type);
	129	int type = bpf_find_probe_type(event_type);
	130	struct perf_event_attr attr = {};
4fe66415 DL	131	struct bpf_link *link;
4fe66415 DL	132	int fd, err = -1;
ecb96f7f YS	133
	134	if (type < 0 \|\| is_return_bit < 0) {
	135	printf("FAIL: %s incorrect type (%d) or is_return_bit (%d)\n",
	136	__func__, type, is_return_bit);
4fe66415	137	return err;
ecb96f7f YS	138	}
	139
	140	attr.sample_period = 1;
	141	attr.wakeup_events = 1;
	142	if (is_return)
	143	attr.config \|= 1 << is_return_bit;
	144
	145	if (name) {
	146	attr.config1 = ptr_to_u64((void *)name);
	147	attr.config2 = offset;
	148	} else {
	149	attr.config1 = 0;
	150	attr.config2 = addr;
	151	}
	152	attr.size = sizeof(attr);
	153	attr.type = type;
	154
	155	fd = sys_perf_event_open(&attr, -1, 0, -1, 0);
4fe66415 DL	156	link = bpf_program__attach_perf_event(progs[0], fd);
	157	if (libbpf_get_error(link)) {
	158	printf("ERROR: bpf_program__attach_perf_event failed\n");
	159	link = NULL;
	160	close(fd);
	161	goto cleanup;
	162	}
ecb96f7f	163
ecb96f7f YS	164	CHECK_PERROR_RET(bpf_task_fd_query(getpid(), fd, 0, buf, buf_len,
ecb96f7f YS	165	prog_id, fd_type, probe_offset, probe_addr) < 0);
4fe66415	166	err = 0;
ecb96f7f	167
4fe66415 DL	168	cleanup:
	169	bpf_link__destroy(link);
	170	return err;
ecb96f7f YS	171	}
	172
	173	static int test_nondebug_fs_probe(const char event_type, const char name,
	174	__u64 offset, __u64 addr, bool is_return,
	175	__u32 expected_fd_type,
	176	__u32 expected_ret_fd_type,
	177	char *buf, __u32 buf_len)
	178	{
	179	__u64 probe_offset, probe_addr;
	180	__u32 prog_id, fd_type;
	181	int err;
	182
	183	err = test_nondebug_fs_kuprobe_common(event_type, name,
	184	offset, addr, is_return,
	185	buf, &buf_len, &prog_id,
	186	&fd_type, &probe_offset,
	187	&probe_addr);
	188	if (err < 0) {
	189	printf("FAIL: %s, "
	190	"for name %s, offset 0x%llx, addr 0x%llx, is_return %d\n",
	191	__func__, name ? name : "", offset, addr, is_return);
	192	perror(" :");
	193	return -1;
	194	}
	195	if ((is_return && fd_type != expected_ret_fd_type) \|\|
	196	(!is_return && fd_type != expected_fd_type)) {
	197	printf("FAIL: %s, incorrect fd_type %u\n",
	198	__func__, fd_type);
	199	return -1;
	200	}
	201	if (name) {
	202	if (strcmp(name, buf) != 0) {
	203	printf("FAIL: %s, incorrect buf %s\n", __func__, buf);
	204	return -1;
	205	}
	206	if (probe_offset != offset) {
	207	printf("FAIL: %s, incorrect probe_offset 0x%llx\n",
	208	__func__, probe_offset);
	209	return -1;
	210	}
	211	} else {
	212	if (buf_len != 0) {
	213	printf("FAIL: %s, incorrect buf %p\n",
	214	__func__, buf);
	215	return -1;
	216	}
	217
	218	if (probe_addr != addr) {
	219	printf("FAIL: %s, incorrect probe_addr 0x%llx\n",
	220	__func__, probe_addr);
	221	return -1;
	222	}
	223	}
	224	return 0;
	225	}
	226
	227	static int test_debug_fs_uprobe(char *binary_path, long offset, bool is_return)
	228	{
4fe66415	229	char buf[256], event_alias[sizeof("test_1234567890")];
ecb96f7f YS	230	const char *event_type = "uprobe";
ecb96f7f YS	231	struct perf_event_attr attr = {};
ecb96f7f YS	232	__u64 probe_offset, probe_addr;
ecb96f7f YS	233	__u32 len, prog_id, fd_type;
4fe66415 DL	234	int err = -1, res, kfd, efd;
4fe66415 DL	235	struct bpf_link *link;
ecb96f7f YS	236	ssize_t bytes;
	237
	238	snprintf(buf, sizeof(buf), "/sys/kernel/debug/tracing/%s_events",
	239	event_type);
4fe66415	240	kfd = open(buf, O_WRONLY \| O_TRUNC, 0);
ecb96f7f YS	241	CHECK_PERROR_RET(kfd < 0);
	242
	243	res = snprintf(event_alias, sizeof(event_alias), "test_%d", getpid());
	244	CHECK_PERROR_RET(res < 0 \|\| res >= sizeof(event_alias));
	245
	246	res = snprintf(buf, sizeof(buf), "%c:%ss/%s %s:0x%lx",
	247	is_return ? 'r' : 'p', event_type, event_alias,
	248	binary_path, offset);
	249	CHECK_PERROR_RET(res < 0 \|\| res >= sizeof(buf));
	250	CHECK_PERROR_RET(write(kfd, buf, strlen(buf)) < 0);
	251
	252	close(kfd);
	253	kfd = -1;
	254
	255	snprintf(buf, sizeof(buf), "/sys/kernel/debug/tracing/events/%ss/%s/id",
	256	event_type, event_alias);
	257	efd = open(buf, O_RDONLY, 0);
	258	CHECK_PERROR_RET(efd < 0);
	259
	260	bytes = read(efd, buf, sizeof(buf));
	261	CHECK_PERROR_RET(bytes <= 0 \|\| bytes >= sizeof(buf));
	262	close(efd);
	263	buf[bytes] = '\0';
	264
	265	attr.config = strtol(buf, NULL, 0);
	266	attr.type = PERF_TYPE_TRACEPOINT;
	267	attr.sample_period = 1;
	268	attr.wakeup_events = 1;
4fe66415	269
ecb96f7f	270	kfd = sys_perf_event_open(&attr, -1, 0, -1, PERF_FLAG_FD_CLOEXEC);
4fe66415 DL	271	link = bpf_program__attach_perf_event(progs[0], kfd);
	272	if (libbpf_get_error(link)) {
	273	printf("ERROR: bpf_program__attach_perf_event failed\n");
	274	link = NULL;
	275	close(kfd);
	276	goto cleanup;
	277	}
ecb96f7f YS	278
	279	len = sizeof(buf);
	280	err = bpf_task_fd_query(getpid(), kfd, 0, buf, &len,
	281	&prog_id, &fd_type, &probe_offset,
	282	&probe_addr);
	283	if (err < 0) {
	284	printf("FAIL: %s, binary_path %s\n", __func__, binary_path);
	285	perror(" :");
	286	return -1;
	287	}
	288	if ((is_return && fd_type != BPF_FD_TYPE_URETPROBE) \|\|
	289	(!is_return && fd_type != BPF_FD_TYPE_UPROBE)) {
	290	printf("FAIL: %s, incorrect fd_type %u\n", __func__,
	291	fd_type);
	292	return -1;
	293	}
	294	if (strcmp(binary_path, buf) != 0) {
	295	printf("FAIL: %s, incorrect buf %s\n", __func__, buf);
	296	return -1;
	297	}
	298	if (probe_offset != offset) {
	299	printf("FAIL: %s, incorrect probe_offset 0x%llx\n", __func__,
	300	probe_offset);
	301	return -1;
	302	}
4fe66415	303	err = 0;
ecb96f7f	304
4fe66415 DL	305	cleanup:
	306	bpf_link__destroy(link);
	307	return err;
ecb96f7f YS	308	}
	309
	310	int main(int argc, char **argv)
	311	{
ecb96f7f YS	312	extern char __executable_start;
	313	char filename[256], buf[256];
	314	__u64 uprobe_file_offset;
4fe66415 DL	315	struct bpf_program *prog;
	316	struct bpf_object *obj;
	317	int i = 0, err = -1;
ecb96f7f	318
ecb96f7f YS	319	if (load_kallsyms()) {
ecb96f7f YS	320	printf("failed to process /proc/kallsyms\n");
4fe66415 DL	321	return err;
	322	}
	323
	324	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
	325	obj = bpf_object__open_file(filename, NULL);
	326	if (libbpf_get_error(obj)) {
	327	fprintf(stderr, "ERROR: opening BPF object file failed\n");
	328	return err;
ecb96f7f YS	329	}
ecb96f7f YS	330
4fe66415 DL	331	/* load BPF program */
	332	if (bpf_object__load(obj)) {
	333	fprintf(stderr, "ERROR: loading BPF object file failed\n");
	334	goto cleanup;
	335	}
	336
	337	bpf_object__for_each_program(prog, obj) {
	338	progs[i] = prog;
	339	links[i] = bpf_program__attach(progs[i]);
	340	if (libbpf_get_error(links[i])) {
	341	fprintf(stderr, "ERROR: bpf_program__attach failed\n");
	342	links[i] = NULL;
	343	goto cleanup;
	344	}
	345	i++;
ecb96f7f YS	346	}
	347
	348	/* test two functions in the corresponding _kern.c file /
d2e614cb	349	CHECK_AND_RET(test_debug_fs_kprobe(0, "blk_mq_start_request",
ecb96f7f	350	BPF_FD_TYPE_KPROBE));
bc069da6	351	CHECK_AND_RET(test_debug_fs_kprobe(1, "__blk_account_io_done",
ecb96f7f YS	352	BPF_FD_TYPE_KRETPROBE));
	353
	354	/* test nondebug fs kprobe */
	355	CHECK_AND_RET(test_nondebug_fs_probe("kprobe", "bpf_check", 0x0, 0x0,
	356	false, BPF_FD_TYPE_KPROBE,
	357	BPF_FD_TYPE_KRETPROBE,
	358	buf, sizeof(buf)));
	359	#ifdef __x86_64__
	360	/* set a kprobe on "bpf_check + 0x5", which is x64 specific */
	361	CHECK_AND_RET(test_nondebug_fs_probe("kprobe", "bpf_check", 0x5, 0x0,
	362	false, BPF_FD_TYPE_KPROBE,
	363	BPF_FD_TYPE_KRETPROBE,
	364	buf, sizeof(buf)));
	365	#endif
	366	CHECK_AND_RET(test_nondebug_fs_probe("kprobe", "bpf_check", 0x0, 0x0,
	367	true, BPF_FD_TYPE_KPROBE,
	368	BPF_FD_TYPE_KRETPROBE,
	369	buf, sizeof(buf)));
	370	CHECK_AND_RET(test_nondebug_fs_probe("kprobe", NULL, 0x0,
	371	ksym_get_addr("bpf_check"), false,
	372	BPF_FD_TYPE_KPROBE,
	373	BPF_FD_TYPE_KRETPROBE,
	374	buf, sizeof(buf)));
	375	CHECK_AND_RET(test_nondebug_fs_probe("kprobe", NULL, 0x0,
	376	ksym_get_addr("bpf_check"), false,
	377	BPF_FD_TYPE_KPROBE,
	378	BPF_FD_TYPE_KRETPROBE,
	379	NULL, 0));
	380	CHECK_AND_RET(test_nondebug_fs_probe("kprobe", NULL, 0x0,
	381	ksym_get_addr("bpf_check"), true,
	382	BPF_FD_TYPE_KPROBE,
	383	BPF_FD_TYPE_KRETPROBE,
	384	buf, sizeof(buf)));
	385	CHECK_AND_RET(test_nondebug_fs_probe("kprobe", NULL, 0x0,
	386	ksym_get_addr("bpf_check"), true,
	387	BPF_FD_TYPE_KPROBE,
	388	BPF_FD_TYPE_KRETPROBE,
	389	0, 0));
	390
	391	/* test nondebug fs uprobe */
	392	/* the calculation of uprobe file offset is based on gcc 7.3.1 on x64
	393	* and the default linker script, which defines __executable_start as
	394	* the start of the .text section. The calculation could be different
	395	* on different systems with different compilers. The right way is
	396	* to parse the ELF file. We took a shortcut here.
	397	*/
0303ce17	398	uprobe_file_offset = (unsigned long)main - (unsigned long)&__executable_start;
ecb96f7f YS	399	CHECK_AND_RET(test_nondebug_fs_probe("uprobe", (char *)argv[0],
	400	uprobe_file_offset, 0x0, false,
	401	BPF_FD_TYPE_UPROBE,
	402	BPF_FD_TYPE_URETPROBE,
	403	buf, sizeof(buf)));
	404	CHECK_AND_RET(test_nondebug_fs_probe("uprobe", (char *)argv[0],
	405	uprobe_file_offset, 0x0, true,
	406	BPF_FD_TYPE_UPROBE,
	407	BPF_FD_TYPE_URETPROBE,
	408	buf, sizeof(buf)));
	409
	410	/* test debug fs uprobe */
	411	CHECK_AND_RET(test_debug_fs_uprobe((char *)argv[0], uprobe_file_offset,
	412	false));
	413	CHECK_AND_RET(test_debug_fs_uprobe((char *)argv[0], uprobe_file_offset,
	414	true));
4fe66415	415	err = 0;
ecb96f7f	416
4fe66415 DL	417	cleanup:
	418	for (i--; i >= 0; i--)
	419	bpf_link__destroy(links[i]);
	420
	421	bpf_object__close(obj);
	422	return err;
ecb96f7f	423	}