Commit ab963beb authored by Alexei Starovoitov's avatar Alexei Starovoitov Committed by Daniel Borkmann
Browse files

selftests/bpf: add bpf_spin_lock C test 



add bpf_spin_lock C based test that requires latest llvm with BTF support

Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
parent b4d4556c

tools/testing/selftests/bpf/Makefile

+1 −1
Original line number Diff line number Diff line
@@ -35,7 +35,7 @@ BPF_OBJ_FILES = \ 
	sendmsg4_prog.o sendmsg6_prog.o test_lirc_mode2_kern.o \

	get_cgroup_id_kern.o socket_cookie_prog.o test_select_reuseport_kern.o \

	test_skb_cgroup_id_kern.o bpf_flow.o netcnt_prog.o test_xdp_vlan.o \

	xdp_dummy.o test_map_in_map.o

	xdp_dummy.o test_map_in_map.o test_spin_lock.o



# Objects are built with default compilation flags and with sub-register

# code-gen enabled.

tools/testing/selftests/bpf/bpf_helpers.h

+4 −0
Original line number Diff line number Diff line
@@ -172,6 +172,10 @@ static int (*bpf_skb_vlan_pop)(void *ctx) = 
	(void *) BPF_FUNC_skb_vlan_pop;

static int (*bpf_rc_pointer_rel)(void *ctx, int rel_x, int rel_y) =

	(void *) BPF_FUNC_rc_pointer_rel;

static void (*bpf_spin_lock)(struct bpf_spin_lock *lock) =

	(void *) BPF_FUNC_spin_lock;

static void (*bpf_spin_unlock)(struct bpf_spin_lock *lock) =

	(void *) BPF_FUNC_spin_unlock;



/* llvm builtin functions that eBPF C program may use to

 * emit BPF_LD_ABS and BPF_LD_IND instructions

tools/testing/selftests/bpf/test_progs.c

+42 −1
Original line number Diff line number Diff line
@@ -28,7 +28,7 @@ typedef __u16 __sum16; 
#include <sys/wait.h>

#include <sys/types.h>

#include <fcntl.h>



#include <pthread.h>

#include <linux/bpf.h>

#include <linux/err.h>

#include <bpf/bpf.h>
@@ -1985,6 +1985,46 @@ static void test_flow_dissector(void) 
	bpf_object__close(obj);

}



static void *test_spin_lock(void *arg)

{

	__u32 duration, retval;

	int err, prog_fd = *(u32 *) arg;



	err = bpf_prog_test_run(prog_fd, 10000, &pkt_v4, sizeof(pkt_v4),

				NULL, NULL, &retval, &duration);

	CHECK(err || retval, "",

	      "err %d errno %d retval %d duration %d\n",

	      err, errno, retval, duration);

	pthread_exit(arg);

}



static void test_spinlock(void)

{

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

	pthread_t thread_id[4];

	struct bpf_object *obj;

	int prog_fd;

	int err = 0, i;

	void *ret;



	err = bpf_prog_load(file, BPF_PROG_TYPE_CGROUP_SKB, &obj, &prog_fd);

	if (err) {

		printf("test_spin_lock:bpf_prog_load errno %d\n", errno);

		goto close_prog;

	}

	for (i = 0; i < 4; i++)

		assert(pthread_create(&thread_id[i], NULL,

				      &test_spin_lock, &prog_fd) == 0);

	for (i = 0; i < 4; i++)

		assert(pthread_join(thread_id[i], &ret) == 0 &&

		       ret == (void *)&prog_fd);

	goto close_prog_noerr;

close_prog:

	error_cnt++;

close_prog_noerr:

	bpf_object__close(obj);

}



int main(void)

{

	srand(time(NULL));
@@ -2013,6 +2053,7 @@ int main(void) 
	test_queue_stack_map(QUEUE);

	test_queue_stack_map(STACK);

	test_flow_dissector();

	test_spinlock();



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

	return error_cnt ? EXIT_FAILURE : EXIT_SUCCESS;

tools/testing/selftests/bpf/test_spin_lock.c

0 → 100644
+108 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0

// Copyright (c) 2019 Facebook

#include <linux/bpf.h>

#include <linux/version.h>

#include "bpf_helpers.h"



struct hmap_elem {

	volatile int cnt;

	struct bpf_spin_lock lock;

	int test_padding;

};



struct bpf_map_def SEC("maps") hmap = {

	.type = BPF_MAP_TYPE_HASH,

	.key_size = sizeof(int),

	.value_size = sizeof(struct hmap_elem),

	.max_entries = 1,

};



BPF_ANNOTATE_KV_PAIR(hmap, int, struct hmap_elem);





struct cls_elem {

	struct bpf_spin_lock lock;

	volatile int cnt;

};



struct bpf_map_def SEC("maps") cls_map = {

	.type = BPF_MAP_TYPE_CGROUP_STORAGE,

	.key_size = sizeof(struct bpf_cgroup_storage_key),

	.value_size = sizeof(struct cls_elem),

};



BPF_ANNOTATE_KV_PAIR(cls_map, struct bpf_cgroup_storage_key,

		     struct cls_elem);



struct bpf_vqueue {

	struct bpf_spin_lock lock;

	/* 4 byte hole */

	unsigned long long lasttime;

	int credit;

	unsigned int rate;

};



struct bpf_map_def SEC("maps") vqueue = {

	.type = BPF_MAP_TYPE_ARRAY,

	.key_size = sizeof(int),

	.value_size = sizeof(struct bpf_vqueue),

	.max_entries = 1,

};



BPF_ANNOTATE_KV_PAIR(vqueue, int, struct bpf_vqueue);

#define CREDIT_PER_NS(delta, rate) (((delta) * rate) >> 20)



SEC("spin_lock_demo")

int bpf_sping_lock_test(struct __sk_buff *skb)

{

	volatile int credit = 0, max_credit = 100, pkt_len = 64;

	struct hmap_elem zero = {}, *val;

	unsigned long long curtime;

	struct bpf_vqueue *q;

	struct cls_elem *cls;

	int key = 0;

	int err = 0;



	val = bpf_map_lookup_elem(&hmap, &key);

	if (!val) {

		bpf_map_update_elem(&hmap, &key, &zero, 0);

		val = bpf_map_lookup_elem(&hmap, &key);

		if (!val) {

			err = 1;

			goto err;

		}

	}

	/* spin_lock in hash map run time test */

	bpf_spin_lock(&val->lock);

	if (val->cnt)

		val->cnt--;

	else

		val->cnt++;

	if (val->cnt != 0 && val->cnt != 1)

		err = 1;

	bpf_spin_unlock(&val->lock);



	/* spin_lock in array. virtual queue demo */

	q = bpf_map_lookup_elem(&vqueue, &key);

	if (!q)

		goto err;

	curtime = bpf_ktime_get_ns();

	bpf_spin_lock(&q->lock);

	q->credit += CREDIT_PER_NS(curtime - q->lasttime, q->rate);

	q->lasttime = curtime;

	if (q->credit > max_credit)

		q->credit = max_credit;

	q->credit -= pkt_len;

	credit = q->credit;

	bpf_spin_unlock(&q->lock);



	/* spin_lock in cgroup local storage */

	cls = bpf_get_local_storage(&cls_map, 0);

	bpf_spin_lock(&cls->lock);

	cls->cnt++;

	bpf_spin_unlock(&cls->lock);



err:

	return err;

}

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