Commit 9de7f0fd authored by Yonghong Song's avatar Yonghong Song Committed by Alexei Starovoitov
Browse files

selftests/bpf: Add hashmap test for bpf_for_each_map_elem() helper 



A test case is added for hashmap and percpu hashmap. The test
also exercises nested bpf_for_each_map_elem() calls like
    bpf_prog:
      bpf_for_each_map_elem(func1)
    func1:
      bpf_for_each_map_elem(func2)
    func2:

  $ ./test_progs -n 45
  #45/1 hash_map:OK
  #45 for_each:OK
  Summary: 1/1 PASSED, 0 SKIPPED, 0 FAILED

Signed-off-by: default avatarYonghong Song <yhs@fb.com>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
Acked-by: default avatarAndrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210226204933.3885657-1-yhs@fb.com
parent f1f9f0d8

tools/testing/selftests/bpf/prog_tests/for_each.c

0 → 100644
+73 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0

/* Copyright (c) 2021 Facebook */

#include <test_progs.h>

#include <network_helpers.h>

#include "for_each_hash_map_elem.skel.h"



static unsigned int duration;



static void test_hash_map(void)

{

	int i, err, hashmap_fd, max_entries, percpu_map_fd;

	struct for_each_hash_map_elem *skel;

	__u64 *percpu_valbuf = NULL;

	__u32 key, num_cpus, retval;

	__u64 val;



	skel = for_each_hash_map_elem__open_and_load();

	if (!ASSERT_OK_PTR(skel, "for_each_hash_map_elem__open_and_load"))

		return;



	hashmap_fd = bpf_map__fd(skel->maps.hashmap);

	max_entries = bpf_map__max_entries(skel->maps.hashmap);

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

		key = i;

		val = i + 1;

		err = bpf_map_update_elem(hashmap_fd, &key, &val, BPF_ANY);

		if (!ASSERT_OK(err, "map_update"))

			goto out;

	}



	num_cpus = bpf_num_possible_cpus();

	percpu_map_fd = bpf_map__fd(skel->maps.percpu_map);

	percpu_valbuf = malloc(sizeof(__u64) * num_cpus);

	if (!ASSERT_OK_PTR(percpu_valbuf, "percpu_valbuf"))

		goto out;



	key = 1;

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

		percpu_valbuf[i] = i + 1;

	err = bpf_map_update_elem(percpu_map_fd, &key, percpu_valbuf, BPF_ANY);

	if (!ASSERT_OK(err, "percpu_map_update"))

		goto out;



	err = bpf_prog_test_run(bpf_program__fd(skel->progs.test_pkt_access),

				1, &pkt_v4, sizeof(pkt_v4), NULL, NULL,

				&retval, &duration);

	if (CHECK(err || retval, "ipv4", "err %d errno %d retval %d\n",

		  err, errno, retval))

		goto out;



	ASSERT_EQ(skel->bss->hashmap_output, 4, "hashmap_output");

	ASSERT_EQ(skel->bss->hashmap_elems, max_entries, "hashmap_elems");



	key = 1;

	err = bpf_map_lookup_elem(hashmap_fd, &key, &val);

	ASSERT_ERR(err, "hashmap_lookup");



	ASSERT_EQ(skel->bss->percpu_called, 1, "percpu_called");

	ASSERT_LT(skel->bss->cpu, num_cpus, "num_cpus");

	ASSERT_EQ(skel->bss->percpu_map_elems, 1, "percpu_map_elems");

	ASSERT_EQ(skel->bss->percpu_key, 1, "percpu_key");

	ASSERT_EQ(skel->bss->percpu_val, skel->bss->cpu + 1, "percpu_val");

	ASSERT_EQ(skel->bss->percpu_output, 100, "percpu_output");

out:

	free(percpu_valbuf);

	for_each_hash_map_elem__destroy(skel);

}



void test_for_each(void)

{

	if (test__start_subtest("hash_map"))

		test_hash_map();

}

tools/testing/selftests/bpf/progs/for_each_hash_map_elem.c

0 → 100644
+95 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0

/* Copyright (c) 2021 Facebook */

#include "vmlinux.h"

#include <bpf/bpf_helpers.h>



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



struct {

	__uint(type, BPF_MAP_TYPE_HASH);

	__uint(max_entries, 3);

	__type(key, __u32);

	__type(value, __u64);

} hashmap SEC(".maps");



struct {

	__uint(type, BPF_MAP_TYPE_PERCPU_HASH);

	__uint(max_entries, 1);

	__type(key, __u32);

	__type(value, __u64);

} percpu_map SEC(".maps");



struct callback_ctx {

	struct __sk_buff *ctx;

	int input;

	int output;

};



static __u64

check_hash_elem(struct bpf_map *map, __u32 *key, __u64 *val,

		struct callback_ctx *data)

{

	struct __sk_buff *skb = data->ctx;

	__u32 k;

	__u64 v;



	if (skb) {

		k = *key;

		v = *val;

		if (skb->len == 10000 && k == 10 && v == 10)

			data->output = 3; /* impossible path */

		else

			data->output = 4;

	} else {

		data->output = data->input;

		bpf_map_delete_elem(map, key);

	}



	return 0;

}



__u32 cpu = 0;

__u32 percpu_called = 0;

__u32 percpu_key = 0;

__u64 percpu_val = 0;

int percpu_output = 0;



static __u64

check_percpu_elem(struct bpf_map *map, __u32 *key, __u64 *val,

		  struct callback_ctx *unused)

{

	struct callback_ctx data;



	percpu_called++;

	cpu = bpf_get_smp_processor_id();

	percpu_key = *key;

	percpu_val = *val;



	data.ctx = 0;

	data.input = 100;

	data.output = 0;

	bpf_for_each_map_elem(&hashmap, check_hash_elem, &data, 0);

	percpu_output = data.output;



	return 0;

}



int hashmap_output = 0;

int hashmap_elems = 0;

int percpu_map_elems = 0;



SEC("classifier")

int test_pkt_access(struct __sk_buff *skb)

{

	struct callback_ctx data;



	data.ctx = skb;

	data.input = 10;

	data.output = 0;

	hashmap_elems = bpf_for_each_map_elem(&hashmap, check_hash_elem, &data, 0);

	hashmap_output = data.output;



	percpu_map_elems = bpf_for_each_map_elem(&percpu_map, check_percpu_elem,

						 (void *)0, 0);

	return 0;

}

tools/testing/selftests/bpf/test_progs.h

+11 −0
Original line number Diff line number Diff line
@@ -152,6 +152,17 @@ extern int test__join_cgroup(const char *path); 
	___ok;								\

})



#define ASSERT_LT(actual, expected, name) ({				\

	static int duration = 0;					\

	typeof(actual) ___act = (actual);				\

	typeof(expected) ___exp = (expected);				\

	bool ___ok = ___act < ___exp;					\

	CHECK(!___ok, (name),						\

	      "unexpected %s: actual %lld >= expected %lld\n",		\

	      (name), (long long)(___act), (long long)(___exp));	\

	___ok;								\

})



#define ASSERT_STREQ(actual, expected, name) ({				\

	static int duration = 0;					\

	const char *___act = actual;					\