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Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
selftests/bpf: Test load and dump metadata with btftool and skel
This is a simple test to check that loading and dumping metadata
in btftool works, whether or not metadata contents are used by the
program.
A C test is also added to make sure the skeleton code can read the
metadata values.
Signed-off-by: YiFei Zhu <zhuyifei@google.com>
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Cc: YiFei Zhu <zhuyifei1999@gmail.com>
Link: https://lore.kernel.org/bpf/20200915234543.3220146-6-sdf@google.com
authored by
YiFei Zhu
and committed by
Alexei Starovoitov
d42d1cc4
aff52e68
+255
-1
+2
-1
tools/testing/selftests/bpf/Makefile
+2
-1
tools/testing/selftests/bpf/Makefile
+141
tools/testing/selftests/bpf/prog_tests/metadata.c
+141
tools/testing/selftests/bpf/prog_tests/metadata.c
···
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// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Copyright 2020 Google LLC.
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*/
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#include <test_progs.h>
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#include <cgroup_helpers.h>
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#include <network_helpers.h>
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#include "metadata_unused.skel.h"
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#include "metadata_used.skel.h"
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static int duration;
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static int prog_holds_map(int prog_fd, int map_fd)
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{
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struct bpf_prog_info prog_info = {};
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struct bpf_prog_info map_info = {};
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__u32 prog_info_len;
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__u32 map_info_len;
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__u32 *map_ids;
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int nr_maps;
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int ret;
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int i;
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map_info_len = sizeof(map_info);
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ret = bpf_obj_get_info_by_fd(map_fd, &map_info, &map_info_len);
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if (ret)
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return -errno;
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prog_info_len = sizeof(prog_info);
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ret = bpf_obj_get_info_by_fd(prog_fd, &prog_info, &prog_info_len);
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if (ret)
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return -errno;
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map_ids = calloc(prog_info.nr_map_ids, sizeof(__u32));
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if (!map_ids)
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return -ENOMEM;
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nr_maps = prog_info.nr_map_ids;
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memset(&prog_info, 0, sizeof(prog_info));
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prog_info.nr_map_ids = nr_maps;
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prog_info.map_ids = ptr_to_u64(map_ids);
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prog_info_len = sizeof(prog_info);
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ret = bpf_obj_get_info_by_fd(prog_fd, &prog_info, &prog_info_len);
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if (ret) {
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ret = -errno;
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goto free_map_ids;
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}
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ret = -ENOENT;
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for (i = 0; i < prog_info.nr_map_ids; i++) {
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if (map_ids[i] == map_info.id) {
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ret = 0;
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break;
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}
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}
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free_map_ids:
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free(map_ids);
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return ret;
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}
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static void test_metadata_unused(void)
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{
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struct metadata_unused *obj;
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int err;
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obj = metadata_unused__open_and_load();
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if (CHECK(!obj, "skel-load", "errno %d", errno))
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return;
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err = prog_holds_map(bpf_program__fd(obj->progs.prog),
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bpf_map__fd(obj->maps.rodata));
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if (CHECK(err, "prog-holds-rodata", "errno: %d", err))
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return;
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/* Assert that we can access the metadata in skel and the values are
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* what we expect.
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*/
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if (CHECK(strncmp(obj->rodata->bpf_metadata_a, "foo",
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sizeof(obj->rodata->bpf_metadata_a)),
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"bpf_metadata_a", "expected \"foo\", value differ"))
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goto close_bpf_object;
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if (CHECK(obj->rodata->bpf_metadata_b != 1, "bpf_metadata_b",
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"expected 1, got %d", obj->rodata->bpf_metadata_b))
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goto close_bpf_object;
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/* Assert that binding metadata map to prog again succeeds. */
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err = bpf_prog_bind_map(bpf_program__fd(obj->progs.prog),
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bpf_map__fd(obj->maps.rodata), NULL);
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CHECK(err, "rebind_map", "errno %d, expected 0", errno);
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close_bpf_object:
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metadata_unused__destroy(obj);
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}
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static void test_metadata_used(void)
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{
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struct metadata_used *obj;
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int err;
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obj = metadata_used__open_and_load();
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if (CHECK(!obj, "skel-load", "errno %d", errno))
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return;
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err = prog_holds_map(bpf_program__fd(obj->progs.prog),
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bpf_map__fd(obj->maps.rodata));
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if (CHECK(err, "prog-holds-rodata", "errno: %d", err))
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return;
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/* Assert that we can access the metadata in skel and the values are
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* what we expect.
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*/
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if (CHECK(strncmp(obj->rodata->bpf_metadata_a, "bar",
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sizeof(obj->rodata->bpf_metadata_a)),
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"metadata_a", "expected \"bar\", value differ"))
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goto close_bpf_object;
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if (CHECK(obj->rodata->bpf_metadata_b != 2, "metadata_b",
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"expected 2, got %d", obj->rodata->bpf_metadata_b))
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goto close_bpf_object;
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/* Assert that binding metadata map to prog again succeeds. */
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err = bpf_prog_bind_map(bpf_program__fd(obj->progs.prog),
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bpf_map__fd(obj->maps.rodata), NULL);
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CHECK(err, "rebind_map", "errno %d, expected 0", errno);
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close_bpf_object:
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metadata_used__destroy(obj);
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}
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void test_metadata(void)
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{
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if (test__start_subtest("unused"))
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test_metadata_unused();
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if (test__start_subtest("used"))
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test_metadata_used();
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}
+15
tools/testing/selftests/bpf/progs/metadata_unused.c
+15
tools/testing/selftests/bpf/progs/metadata_unused.c
···
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// SPDX-License-Identifier: GPL-2.0-only
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#include <linux/bpf.h>
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#include <bpf/bpf_helpers.h>
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volatile const char bpf_metadata_a[] SEC(".rodata") = "foo";
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volatile const int bpf_metadata_b SEC(".rodata") = 1;
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SEC("cgroup_skb/egress")
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int prog(struct xdp_md *ctx)
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{
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return 0;
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}
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char _license[] SEC("license") = "GPL";
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tools/testing/selftests/bpf/progs/metadata_used.c
+15
tools/testing/selftests/bpf/progs/metadata_used.c
···
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// SPDX-License-Identifier: GPL-2.0-only
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#include <linux/bpf.h>
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#include <bpf/bpf_helpers.h>
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volatile const char bpf_metadata_a[] SEC(".rodata") = "bar";
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volatile const int bpf_metadata_b SEC(".rodata") = 2;
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SEC("cgroup_skb/egress")
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int prog(struct xdp_md *ctx)
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{
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return bpf_metadata_b ? 1 : 0;
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}
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char _license[] SEC("license") = "GPL";
+82
tools/testing/selftests/bpf/test_bpftool_metadata.sh
+82
tools/testing/selftests/bpf/test_bpftool_metadata.sh
···
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#!/bin/sh
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# SPDX-License-Identifier: GPL-2.0
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# Kselftest framework requirement - SKIP code is 4.
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ksft_skip=4
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TESTNAME=bpftool_metadata
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BPF_FS=$(awk '$3 == "bpf" {print $2; exit}' /proc/mounts)
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BPF_DIR=$BPF_FS/test_$TESTNAME
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_cleanup()
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{
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set +e
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rm -rf $BPF_DIR 2> /dev/null
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}
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cleanup_skip()
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{
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echo "selftests: $TESTNAME [SKIP]"
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_cleanup
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exit $ksft_skip
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}
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cleanup()
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{
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if [ "$?" = 0 ]; then
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echo "selftests: $TESTNAME [PASS]"
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else
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echo "selftests: $TESTNAME [FAILED]"
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fi
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_cleanup
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}
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if [ $(id -u) -ne 0 ]; then
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echo "selftests: $TESTNAME [SKIP] Need root privileges"
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exit $ksft_skip
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fi
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if [ -z "$BPF_FS" ]; then
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echo "selftests: $TESTNAME [SKIP] Could not run test without bpffs mounted"
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exit $ksft_skip
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fi
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if ! bpftool version > /dev/null 2>&1; then
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echo "selftests: $TESTNAME [SKIP] Could not run test without bpftool"
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exit $ksft_skip
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fi
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set -e
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trap cleanup_skip EXIT
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mkdir $BPF_DIR
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trap cleanup EXIT
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bpftool prog load metadata_unused.o $BPF_DIR/unused
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METADATA_PLAIN="$(bpftool prog)"
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echo "$METADATA_PLAIN" | grep 'a = "foo"' > /dev/null
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echo "$METADATA_PLAIN" | grep 'b = 1' > /dev/null
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bpftool prog --json | grep '"metadata":{"a":"foo","b":1}' > /dev/null
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bpftool map | grep 'metadata.rodata' > /dev/null
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rm $BPF_DIR/unused
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bpftool prog load metadata_used.o $BPF_DIR/used
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METADATA_PLAIN="$(bpftool prog)"
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echo "$METADATA_PLAIN" | grep 'a = "bar"' > /dev/null
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echo "$METADATA_PLAIN" | grep 'b = 2' > /dev/null
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bpftool prog --json | grep '"metadata":{"a":"bar","b":2}' > /dev/null
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bpftool map | grep 'metadata.rodata' > /dev/null
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rm $BPF_DIR/used
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exit 0