Commit 08f71a1e authored by Martynas Pumputis's avatar Martynas Pumputis Committed by Andrii Nakryiko
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selftests/bpf: Check inner map deletion 



Add a test case to check whether an unsuccessful creation of an outer
map of a BTF-defined map-in-map destroys the inner map.

As bpf_object__create_map() is a static function, we cannot just call it
from the test case and then check whether a map accessible via
map->inner_map_fd has been closed. Instead, we iterate over all maps and
check whether the map "$MAP_NAME.inner" does not exist.

Signed-off-by: default avatarMartynas Pumputis <m@lambda.lt>
Signed-off-by: default avatarAndrii Nakryiko <andrii@kernel.org>
Acked-by: default avatarJohn Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20210719173838.423148-3-m@lambda.lt
parent a21ab4c5

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

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

/* Copyright (c) 2021 Isovalent, Inc. */

#include <linux/bpf.h>

#include <bpf/bpf_helpers.h>



struct inner {

	__uint(type, BPF_MAP_TYPE_ARRAY);

	__type(key, __u32);

	__type(value, int);

	__uint(max_entries, 4);

};



struct {

	__uint(type, BPF_MAP_TYPE_ARRAY_OF_MAPS);

	__uint(max_entries, 0); /* This will make map creation to fail */

	__uint(key_size, sizeof(__u32));

	__array(values, struct inner);

} mim SEC(".maps");



SEC("xdp")

int xdp_noop0(struct xdp_md *ctx)

{

	return XDP_PASS;

}



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

tools/testing/selftests/bpf/test_maps.c

+62 −1
Original line number Diff line number Diff line
@@ -1153,12 +1153,16 @@ static void test_sockmap(unsigned int tasks, void *data) 
}



#define MAPINMAP_PROG "./test_map_in_map.o"

#define MAPINMAP_INVALID_PROG "./test_map_in_map_invalid.o"

static void test_map_in_map(void)

{

	struct bpf_object *obj;

	struct bpf_map *map;

	int mim_fd, fd, err;

	int pos = 0;

	struct bpf_map_info info = {};

	__u32 len = sizeof(info);

	__u32 id = 0;



	obj = bpf_object__open(MAPINMAP_PROG);
@@ -1228,10 +1232,67 @@ static void test_map_in_map(void) 
	}



	close(fd);

	fd = -1;

	bpf_object__close(obj);



	/* Test that failing bpf_object__create_map() destroys the inner map */

	obj = bpf_object__open(MAPINMAP_INVALID_PROG);

	err = libbpf_get_error(obj);

	if (err) {

		printf("Failed to load %s program: %d %d",

		       MAPINMAP_INVALID_PROG, err, errno);

		goto out_map_in_map;

	}



	map = bpf_object__find_map_by_name(obj, "mim");

	if (!map) {

		printf("Failed to load array of maps from test prog\n");

		goto out_map_in_map;

	}



	err = bpf_object__load(obj);

	if (!err) {

		printf("Loading obj supposed to fail\n");

		goto out_map_in_map;

	}



	/* Iterate over all maps to check whether the internal map

	 * ("mim.internal") has been destroyed.

	 */

	while (true) {

		err = bpf_map_get_next_id(id, &id);

		if (err) {

			if (errno == ENOENT)

				break;

			printf("Failed to get next map: %d", errno);

			goto out_map_in_map;

		}



		fd = bpf_map_get_fd_by_id(id);

		if (fd < 0) {

			if (errno == ENOENT)

				continue;

			printf("Failed to get map by id %u: %d", id, errno);

			goto out_map_in_map;

		}



		err = bpf_obj_get_info_by_fd(fd, &info, &len);

		if (err) {

			printf("Failed to get map info by fd %d: %d", fd,

			       errno);

			goto out_map_in_map;

		}



		if (!strcmp(info.name, "mim.inner")) {

			printf("Inner map mim.inner was not destroyed\n");

			goto out_map_in_map;

		}

	}



	return;



out_map_in_map:

	if (fd >= 0)

		close(fd);

	exit(1);

}