From d42d1cc44d702123d6ff12ce54a0e854036d29cb Mon Sep 17 00:00:00 2001 From: YiFei Zhu Date: Tue, 15 Sep 2020 16:45:43 -0700 Subject: [PATCH] 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 Signed-off-by: Stanislav Fomichev Signed-off-by: Alexei Starovoitov Acked-by: Andrii Nakryiko Cc: YiFei Zhu Link: https://lore.kernel.org/bpf/20200915234543.3220146-6-sdf@google.com --- tools/testing/selftests/bpf/Makefile | 3 +- tools/testing/selftests/bpf/prog_tests/metadata.c | 141 +++++++++++++++++++++ .../testing/selftests/bpf/progs/metadata_unused.c | 15 +++ tools/testing/selftests/bpf/progs/metadata_used.c | 15 +++ .../testing/selftests/bpf/test_bpftool_metadata.sh | 82 ++++++++++++ 5 files changed, 255 insertions(+), 1 deletion(-) create mode 100644 tools/testing/selftests/bpf/prog_tests/metadata.c create mode 100644 tools/testing/selftests/bpf/progs/metadata_unused.c create mode 100644 tools/testing/selftests/bpf/progs/metadata_used.c create mode 100755 tools/testing/selftests/bpf/test_bpftool_metadata.sh diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile index 05798c2b5c67..2a63791177c4 100644 --- a/tools/testing/selftests/bpf/Makefile +++ b/tools/testing/selftests/bpf/Makefile @@ -68,7 +68,8 @@ TEST_PROGS := test_kmod.sh \ test_tc_edt.sh \ test_xdping.sh \ test_bpftool_build.sh \ - test_bpftool.sh + test_bpftool.sh \ + test_bpftool_metadata.sh \ TEST_PROGS_EXTENDED := with_addr.sh \ with_tunnels.sh \ diff --git a/tools/testing/selftests/bpf/prog_tests/metadata.c b/tools/testing/selftests/bpf/prog_tests/metadata.c new file mode 100644 index 000000000000..2c53eade88e3 --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/metadata.c @@ -0,0 +1,141 @@ +// SPDX-License-Identifier: GPL-2.0-only + +/* + * Copyright 2020 Google LLC. + */ + +#include +#include +#include + +#include "metadata_unused.skel.h" +#include "metadata_used.skel.h" + +static int duration; + +static int prog_holds_map(int prog_fd, int map_fd) +{ + struct bpf_prog_info prog_info = {}; + struct bpf_prog_info map_info = {}; + __u32 prog_info_len; + __u32 map_info_len; + __u32 *map_ids; + int nr_maps; + int ret; + int i; + + map_info_len = sizeof(map_info); + ret = bpf_obj_get_info_by_fd(map_fd, &map_info, &map_info_len); + if (ret) + return -errno; + + prog_info_len = sizeof(prog_info); + ret = bpf_obj_get_info_by_fd(prog_fd, &prog_info, &prog_info_len); + if (ret) + return -errno; + + map_ids = calloc(prog_info.nr_map_ids, sizeof(__u32)); + if (!map_ids) + return -ENOMEM; + + nr_maps = prog_info.nr_map_ids; + memset(&prog_info, 0, sizeof(prog_info)); + prog_info.nr_map_ids = nr_maps; + prog_info.map_ids = ptr_to_u64(map_ids); + prog_info_len = sizeof(prog_info); + + ret = bpf_obj_get_info_by_fd(prog_fd, &prog_info, &prog_info_len); + if (ret) { + ret = -errno; + goto free_map_ids; + } + + ret = -ENOENT; + for (i = 0; i < prog_info.nr_map_ids; i++) { + if (map_ids[i] == map_info.id) { + ret = 0; + break; + } + } + +free_map_ids: + free(map_ids); + return ret; +} + +static void test_metadata_unused(void) +{ + struct metadata_unused *obj; + int err; + + obj = metadata_unused__open_and_load(); + if (CHECK(!obj, "skel-load", "errno %d", errno)) + return; + + err = prog_holds_map(bpf_program__fd(obj->progs.prog), + bpf_map__fd(obj->maps.rodata)); + if (CHECK(err, "prog-holds-rodata", "errno: %d", err)) + return; + + /* Assert that we can access the metadata in skel and the values are + * what we expect. + */ + if (CHECK(strncmp(obj->rodata->bpf_metadata_a, "foo", + sizeof(obj->rodata->bpf_metadata_a)), + "bpf_metadata_a", "expected \"foo\", value differ")) + goto close_bpf_object; + if (CHECK(obj->rodata->bpf_metadata_b != 1, "bpf_metadata_b", + "expected 1, got %d", obj->rodata->bpf_metadata_b)) + goto close_bpf_object; + + /* Assert that binding metadata map to prog again succeeds. */ + err = bpf_prog_bind_map(bpf_program__fd(obj->progs.prog), + bpf_map__fd(obj->maps.rodata), NULL); + CHECK(err, "rebind_map", "errno %d, expected 0", errno); + +close_bpf_object: + metadata_unused__destroy(obj); +} + +static void test_metadata_used(void) +{ + struct metadata_used *obj; + int err; + + obj = metadata_used__open_and_load(); + if (CHECK(!obj, "skel-load", "errno %d", errno)) + return; + + err = prog_holds_map(bpf_program__fd(obj->progs.prog), + bpf_map__fd(obj->maps.rodata)); + if (CHECK(err, "prog-holds-rodata", "errno: %d", err)) + return; + + /* Assert that we can access the metadata in skel and the values are + * what we expect. + */ + if (CHECK(strncmp(obj->rodata->bpf_metadata_a, "bar", + sizeof(obj->rodata->bpf_metadata_a)), + "metadata_a", "expected \"bar\", value differ")) + goto close_bpf_object; + if (CHECK(obj->rodata->bpf_metadata_b != 2, "metadata_b", + "expected 2, got %d", obj->rodata->bpf_metadata_b)) + goto close_bpf_object; + + /* Assert that binding metadata map to prog again succeeds. */ + err = bpf_prog_bind_map(bpf_program__fd(obj->progs.prog), + bpf_map__fd(obj->maps.rodata), NULL); + CHECK(err, "rebind_map", "errno %d, expected 0", errno); + +close_bpf_object: + metadata_used__destroy(obj); +} + +void test_metadata(void) +{ + if (test__start_subtest("unused")) + test_metadata_unused(); + + if (test__start_subtest("used")) + test_metadata_used(); +} diff --git a/tools/testing/selftests/bpf/progs/metadata_unused.c b/tools/testing/selftests/bpf/progs/metadata_unused.c new file mode 100644 index 000000000000..672a0d19f8d0 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/metadata_unused.c @@ -0,0 +1,15 @@ +// SPDX-License-Identifier: GPL-2.0-only + +#include +#include + +volatile const char bpf_metadata_a[] SEC(".rodata") = "foo"; +volatile const int bpf_metadata_b SEC(".rodata") = 1; + +SEC("cgroup_skb/egress") +int prog(struct xdp_md *ctx) +{ + return 0; +} + +char _license[] SEC("license") = "GPL"; diff --git a/tools/testing/selftests/bpf/progs/metadata_used.c b/tools/testing/selftests/bpf/progs/metadata_used.c new file mode 100644 index 000000000000..b7198e65383d --- /dev/null +++ b/tools/testing/selftests/bpf/progs/metadata_used.c @@ -0,0 +1,15 @@ +// SPDX-License-Identifier: GPL-2.0-only + +#include +#include + +volatile const char bpf_metadata_a[] SEC(".rodata") = "bar"; +volatile const int bpf_metadata_b SEC(".rodata") = 2; + +SEC("cgroup_skb/egress") +int prog(struct xdp_md *ctx) +{ + return bpf_metadata_b ? 1 : 0; +} + +char _license[] SEC("license") = "GPL"; diff --git a/tools/testing/selftests/bpf/test_bpftool_metadata.sh b/tools/testing/selftests/bpf/test_bpftool_metadata.sh new file mode 100755 index 000000000000..1bf81b49457a --- /dev/null +++ b/tools/testing/selftests/bpf/test_bpftool_metadata.sh @@ -0,0 +1,82 @@ +#!/bin/sh +# SPDX-License-Identifier: GPL-2.0 + +# Kselftest framework requirement - SKIP code is 4. +ksft_skip=4 + +TESTNAME=bpftool_metadata +BPF_FS=$(awk '$3 == "bpf" {print $2; exit}' /proc/mounts) +BPF_DIR=$BPF_FS/test_$TESTNAME + +_cleanup() +{ + set +e + rm -rf $BPF_DIR 2> /dev/null +} + +cleanup_skip() +{ + echo "selftests: $TESTNAME [SKIP]" + _cleanup + + exit $ksft_skip +} + +cleanup() +{ + if [ "$?" = 0 ]; then + echo "selftests: $TESTNAME [PASS]" + else + echo "selftests: $TESTNAME [FAILED]" + fi + _cleanup +} + +if [ $(id -u) -ne 0 ]; then + echo "selftests: $TESTNAME [SKIP] Need root privileges" + exit $ksft_skip +fi + +if [ -z "$BPF_FS" ]; then + echo "selftests: $TESTNAME [SKIP] Could not run test without bpffs mounted" + exit $ksft_skip +fi + +if ! bpftool version > /dev/null 2>&1; then + echo "selftests: $TESTNAME [SKIP] Could not run test without bpftool" + exit $ksft_skip +fi + +set -e + +trap cleanup_skip EXIT + +mkdir $BPF_DIR + +trap cleanup EXIT + +bpftool prog load metadata_unused.o $BPF_DIR/unused + +METADATA_PLAIN="$(bpftool prog)" +echo "$METADATA_PLAIN" | grep 'a = "foo"' > /dev/null +echo "$METADATA_PLAIN" | grep 'b = 1' > /dev/null + +bpftool prog --json | grep '"metadata":{"a":"foo","b":1}' > /dev/null + +bpftool map | grep 'metadata.rodata' > /dev/null + +rm $BPF_DIR/unused + +bpftool prog load metadata_used.o $BPF_DIR/used + +METADATA_PLAIN="$(bpftool prog)" +echo "$METADATA_PLAIN" | grep 'a = "bar"' > /dev/null +echo "$METADATA_PLAIN" | grep 'b = 2' > /dev/null + +bpftool prog --json | grep '"metadata":{"a":"bar","b":2}' > /dev/null + +bpftool map | grep 'metadata.rodata' > /dev/null + +rm $BPF_DIR/used + +exit 0 -- 2.11.0