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Commit d279f1f8 authored by Yonghong Song's avatar Yonghong Song Committed by Alexei Starovoitov
Browse files

bpf/tracing: add a bpf test for new ioctl query interface 



Added a subtest in test_progs. The tracepoint is
sched/sched_switch. Multiple bpf programs are attached to
this tracepoint and the query interface is exercised.

Signed-off-by: default avatarYonghong Song <yhs@fb.com>
Acked-by: default avatarAlexei Starovoitov <ast@kernel.org>
Acked-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent f371b304

tools/include/uapi/linux/perf_event.h

+22 −0
Original line number Diff line number Diff line
@@ -418,6 +418,27 @@ struct perf_event_attr { 
	__u16	__reserved_2;	/* align to __u64 */

};



/*

 * Structure used by below PERF_EVENT_IOC_QUERY_BPF command

 * to query bpf programs attached to the same perf tracepoint

 * as the given perf event.

 */

struct perf_event_query_bpf {

	/*

	 * The below ids array length

	 */

	__u32	ids_len;

	/*

	 * Set by the kernel to indicate the number of

	 * available programs

	 */

	__u32	prog_cnt;

	/*

	 * User provided buffer to store program ids

	 */

	__u32	ids[0];

};



#define perf_flags(attr)	(*(&(attr)->read_format + 1))



/*
@@ -433,6 +454,7 @@ struct perf_event_attr { 
#define PERF_EVENT_IOC_ID		_IOR('$', 7, __u64 *)

#define PERF_EVENT_IOC_SET_BPF		_IOW('$', 8, __u32)

#define PERF_EVENT_IOC_PAUSE_OUTPUT	_IOW('$', 9, __u32)

#define PERF_EVENT_IOC_QUERY_BPF	_IOWR('$', 10, struct perf_event_query_bpf *)



enum perf_event_ioc_flags {

	PERF_IOC_FLAG_GROUP		= 1U << 0,

tools/testing/selftests/bpf/Makefile

+1 −1
Original line number Diff line number Diff line
@@ -17,7 +17,7 @@ TEST_GEN_PROGS = test_verifier test_tag test_maps test_lru_map test_lpm_map test 


TEST_GEN_FILES = test_pkt_access.o test_xdp.o test_l4lb.o test_tcp_estats.o test_obj_id.o \

	test_pkt_md_access.o test_xdp_redirect.o test_xdp_meta.o sockmap_parse_prog.o     \

	sockmap_verdict_prog.o dev_cgroup.o sample_ret0.o

	sockmap_verdict_prog.o dev_cgroup.o sample_ret0.o test_tracepoint.o



TEST_PROGS := test_kmod.sh test_xdp_redirect.sh test_xdp_meta.sh \

	test_offload.py

tools/testing/selftests/bpf/test_progs.c

+133 −0
Original line number Diff line number Diff line
@@ -21,8 +21,10 @@ typedef __u16 __sum16; 
#include <linux/ipv6.h>

#include <linux/tcp.h>

#include <linux/filter.h>

#include <linux/perf_event.h>

#include <linux/unistd.h>



#include <sys/ioctl.h>

#include <sys/wait.h>

#include <sys/resource.h>

#include <sys/types.h>
@@ -617,6 +619,136 @@ static void test_obj_name(void) 
	}

}



static void test_tp_attach_query(void)

{

	const int num_progs = 3;

	int i, j, bytes, efd, err, prog_fd[num_progs], pmu_fd[num_progs];

	__u32 duration = 0, info_len, saved_prog_ids[num_progs];

	const char *file = "./test_tracepoint.o";

	struct perf_event_query_bpf *query;

	struct perf_event_attr attr = {};

	struct bpf_object *obj[num_progs];

	struct bpf_prog_info prog_info;

	char buf[256];



	snprintf(buf, sizeof(buf),

		 "/sys/kernel/debug/tracing/events/sched/sched_switch/id");

	efd = open(buf, O_RDONLY, 0);

	if (CHECK(efd < 0, "open", "err %d errno %d\n", efd, errno))

		return;

	bytes = read(efd, buf, sizeof(buf));

	close(efd);

	if (CHECK(bytes <= 0 || bytes >= sizeof(buf),

		  "read", "bytes %d errno %d\n", bytes, errno))

		return;



	attr.config = strtol(buf, NULL, 0);

	attr.type = PERF_TYPE_TRACEPOINT;

	attr.sample_type = PERF_SAMPLE_RAW | PERF_SAMPLE_CALLCHAIN;

	attr.sample_period = 1;

	attr.wakeup_events = 1;



	query = malloc(sizeof(*query) + sizeof(__u32) * num_progs);

	for (i = 0; i < num_progs; i++) {

		err = bpf_prog_load(file, BPF_PROG_TYPE_TRACEPOINT, &obj[i],

				    &prog_fd[i]);

		if (CHECK(err, "prog_load", "err %d errno %d\n", err, errno))

			goto cleanup1;



		bzero(&prog_info, sizeof(prog_info));

		prog_info.jited_prog_len = 0;

		prog_info.xlated_prog_len = 0;

		prog_info.nr_map_ids = 0;

		info_len = sizeof(prog_info);

		err = bpf_obj_get_info_by_fd(prog_fd[i], &prog_info, &info_len);

		if (CHECK(err, "bpf_obj_get_info_by_fd", "err %d errno %d\n",

			  err, errno))

			goto cleanup1;

		saved_prog_ids[i] = prog_info.id;



		pmu_fd[i] = syscall(__NR_perf_event_open, &attr, -1 /* pid */,

				    0 /* cpu 0 */, -1 /* group id */,

				    0 /* flags */);

		if (CHECK(pmu_fd[i] < 0, "perf_event_open", "err %d errno %d\n",

			  pmu_fd[i], errno))

			goto cleanup2;

		err = ioctl(pmu_fd[i], PERF_EVENT_IOC_ENABLE, 0);

		if (CHECK(err, "perf_event_ioc_enable", "err %d errno %d\n",

			  err, errno))

			goto cleanup3;



		if (i == 0) {

			/* check NULL prog array query */

			query->ids_len = num_progs;

			err = ioctl(pmu_fd[i], PERF_EVENT_IOC_QUERY_BPF, query);

			if (CHECK(err || query->prog_cnt != 0,

				  "perf_event_ioc_query_bpf",

				  "err %d errno %d query->prog_cnt %u\n",

				  err, errno, query->prog_cnt))

				goto cleanup3;

		}



		err = ioctl(pmu_fd[i], PERF_EVENT_IOC_SET_BPF, prog_fd[i]);

		if (CHECK(err, "perf_event_ioc_set_bpf", "err %d errno %d\n",

			  err, errno))

			goto cleanup3;



		if (i == 1) {

			/* try to get # of programs only */

			query->ids_len = 0;

			err = ioctl(pmu_fd[i], PERF_EVENT_IOC_QUERY_BPF, query);

			if (CHECK(err || query->prog_cnt != 2,

				  "perf_event_ioc_query_bpf",

				  "err %d errno %d query->prog_cnt %u\n",

				  err, errno, query->prog_cnt))

				goto cleanup3;



			/* try a few negative tests */

			/* invalid query pointer */

			err = ioctl(pmu_fd[i], PERF_EVENT_IOC_QUERY_BPF,

				    (struct perf_event_query_bpf *)0x1);

			if (CHECK(!err || errno != EFAULT,

				  "perf_event_ioc_query_bpf",

				  "err %d errno %d\n", err, errno))

				goto cleanup3;



			/* no enough space */

			query->ids_len = 1;

			err = ioctl(pmu_fd[i], PERF_EVENT_IOC_QUERY_BPF, query);

			if (CHECK(!err || errno != ENOSPC || query->prog_cnt != 2,

				  "perf_event_ioc_query_bpf",

				  "err %d errno %d query->prog_cnt %u\n",

				  err, errno, query->prog_cnt))

				goto cleanup3;

		}



		query->ids_len = num_progs;

		err = ioctl(pmu_fd[i], PERF_EVENT_IOC_QUERY_BPF, query);

		if (CHECK(err || query->prog_cnt != (i + 1),

			  "perf_event_ioc_query_bpf",

			  "err %d errno %d query->prog_cnt %u\n",

			  err, errno, query->prog_cnt))

			goto cleanup3;

		for (j = 0; j < i + 1; j++)

			if (CHECK(saved_prog_ids[j] != query->ids[j],

				  "perf_event_ioc_query_bpf",

				  "#%d saved_prog_id %x query prog_id %x\n",

				  j, saved_prog_ids[j], query->ids[j]))

				goto cleanup3;

	}



	i = num_progs - 1;

	for (; i >= 0; i--) {

 cleanup3:

		ioctl(pmu_fd[i], PERF_EVENT_IOC_DISABLE);

 cleanup2:

		close(pmu_fd[i]);

 cleanup1:

		bpf_object__close(obj[i]);

	}

	free(query);

}



int main(void)

{

	struct rlimit rinf = { RLIM_INFINITY, RLIM_INFINITY };
@@ -630,6 +762,7 @@ int main(void) 
	test_bpf_obj_id();

	test_pkt_md_access();

	test_obj_name();

	test_tp_attach_query();



	printf("Summary: %d PASSED, %d FAILED\n", pass_cnt, error_cnt);

	return error_cnt ? EXIT_FAILURE : EXIT_SUCCESS;

tools/testing/selftests/bpf/test_tracepoint.c

0 → 100644
+26 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0

// Copyright (c) 2017 Facebook



#include <linux/bpf.h>

#include "bpf_helpers.h"



/* taken from /sys/kernel/debug/tracing/events/sched/sched_switch/format */

struct sched_switch_args {

	unsigned long long pad;

	char prev_comm[16];

	int prev_pid;

	int prev_prio;

	long long prev_state;

	char next_comm[16];

	int next_pid;

	int next_prio;

};



SEC("tracepoint/sched/sched_switch")

int oncpu(struct sched_switch_args *ctx)

{

	return 0;

}



char _license[] SEC("license") = "GPL";

__u32 _version SEC("version") = 1; /* ignored by tracepoints, required by libbpf.a */