On Sun, Oct 27, 2019 at 1:53 PM Toke Høiland-Jørgensen <toke@xxxxxxxxxx> wrote:
>
> From: Toke Høiland-Jørgensen <toke@xxxxxxxxxx>
>
> This adds a new BPF selftest to exercise the new automatic map pinning
> code.
>
> Signed-off-by: Toke Høiland-Jørgensen <toke@xxxxxxxxxx>
> ---
> tools/testing/selftests/bpf/prog_tests/pinning.c | 91 ++++++++++++++++++++++
> tools/testing/selftests/bpf/progs/test_pinning.c | 29 +++++++
> 2 files changed, 120 insertions(+)
> create mode 100644 tools/testing/selftests/bpf/prog_tests/pinning.c
> create mode 100644 tools/testing/selftests/bpf/progs/test_pinning.c
>
> diff --git a/tools/testing/selftests/bpf/prog_tests/pinning.c b/tools/testing/selftests/bpf/prog_tests/pinning.c
> new file mode 100644
> index 000000000000..d4a63de72f5a
> --- /dev/null
> +++ b/tools/testing/selftests/bpf/prog_tests/pinning.c
> @@ -0,0 +1,91 @@
> +// SPDX-License-Identifier: GPL-2.0
> +
> +#include <sys/types.h>
> +#include <sys/stat.h>
> +#include <unistd.h>
> +#include <test_progs.h>
> +
> +__u32 get_map_id(struct bpf_object *obj, const char *name)
> +{
> + __u32 map_info_len, duration, retval;
> + struct bpf_map_info map_info = {};
> + struct bpf_map *map;
> + int err;
> +
> + map_info_len = sizeof(map_info);
> +
> + map = bpf_object__find_map_by_name(obj, name);
> + if (!CHECK(!map, "find map", "NULL map")) {
please follow the pattern of "if (CHECK()) { return or goto cleanup
}". There is literally zero cases where we have `if (!CHECK())` in
selftests.
> + err = bpf_obj_get_info_by_fd(bpf_map__fd(map),
> + &map_info, &map_info_len);
> + CHECK(err, "get map info", "err %d errno %d", err, errno);
> + return map_info.id;
> + }
> + return 0;
> +}
> +
> +void test_pinning(void)
> +{
> + __u32 duration, retval, size, map_id, map_id2;
> + const char *custpinpath = "/sys/fs/bpf/custom/pinmap";
> + const char *nopinpath = "/sys/fs/bpf/nopinmap";
> + const char *custpath = "/sys/fs/bpf/custom";
> + const char *pinpath = "/sys/fs/bpf/pinmap";
> + const char *file = "./test_pinning.o";
> + struct stat statbuf = {};
> + struct bpf_object *obj;
> + DECLARE_LIBBPF_OPTS(bpf_object_open_opts, opts,
> + .auto_pin_path = custpath,
> + );
> +
> + int err;
> + obj = bpf_object__open_file(file, NULL);
> + if (CHECK_FAIL(libbpf_get_error(obj)))
> + return;
> +
> + err = bpf_object__load(obj);
> + CHECK(err, "default load", "err %d errno %d\n", err, errno);
cleanup and exit, you don't have a valid set up to proceed with
testing. Same for almost every check below.
> +
> + /* check that pinmap was pinned */
> + err = stat(pinpath, &statbuf);
> + CHECK(err, "stat pinpath", "err %d errno %d\n", err, errno);
> +
> + /* check that nopinmap was *not* pinned */
> + err = stat(nopinpath, &statbuf);
> + CHECK(errno != ENOENT, "stat nopinpath", "err %d errno %d\n", err, errno);
if previous stat succeeded, errno might be from other syscall, you
have to check both
> +
> + map_id = get_map_id(obj, "pinmap");
formatting? check that get_map_id succeeded?
> + bpf_object__close(obj);
> +
> + obj = bpf_object__open_file(file, NULL);
> + if (CHECK_FAIL(libbpf_get_error(obj)))
> + return;
> +
> + err = bpf_object__load(obj);
> + CHECK(err, "default load", "err %d errno %d\n", err, errno);
> +
> + /* check that same map ID was reused for second load */
> + map_id2 = get_map_id(obj, "pinmap");
> + CHECK(map_id != map_id2, "check reuse",
> + "err %d errno %d id %d id2 %d\n", err, errno, map_id, map_id2);
> + unlink(pinpath);
> + bpf_object__close(obj);
> +
> + err = mkdir(custpath, 0700);
> + CHECK(err, "mkdir custpath", "err %d errno %d\n", err, errno);
> +
> + obj = bpf_object__open_file(file, &opts);
> + if (CHECK_FAIL(libbpf_get_error(obj)))
> + return;
> +
> + err = bpf_object__load(obj);
> + CHECK(err, "custom load", "err %d errno %d\n", err, errno);
> +
> + /* check that pinmap was pinned at the custom path */
> + err = stat(custpinpath, &statbuf);
> + CHECK(err, "stat custpinpath", "err %d errno %d\n", err, errno);
> +
> + unlink(custpinpath);
> + rmdir(custpath);
> + bpf_object__close(obj);
> +}
> diff --git a/tools/testing/selftests/bpf/progs/test_pinning.c b/tools/testing/selftests/bpf/progs/test_pinning.c
> new file mode 100644
> index 000000000000..ff2d7447777e
> --- /dev/null
> +++ b/tools/testing/selftests/bpf/progs/test_pinning.c
> @@ -0,0 +1,29 @@
> +// SPDX-License-Identifier: GPL-2.0
> +
> +#include <linux/bpf.h>
> +#include "bpf_helpers.h"
> +
> +int _version SEC("version") = 1;
> +
> +struct {
> + __uint(type, BPF_MAP_TYPE_ARRAY);
> + __uint(max_entries, 1);
> + __type(key, __u32);
> + __type(value, __u64);
> + __uint(pinning, LIBBPF_PIN_BY_NAME);
> +} pinmap SEC(".maps");
> +
> +struct {
> + __uint(type, BPF_MAP_TYPE_ARRAY);
> + __uint(max_entries, 1);
> + __type(key, __u32);
> + __type(value, __u64);
> +} nopinmap SEC(".maps");
> +
> +SEC("xdp_prog")
> +int _xdp_prog(struct xdp_md *xdp)
> +{
> + return XDP_PASS;
> +}
> +
> +char _license[] SEC("license") = "GPL";
>
