Re: [PATCH bpf-next v3 4/4] selftests: Add tests for automatic map pinning
From: Andrii Nakryiko <hidden>
Date: 2019-10-28 18:43:27
Also in:
bpf
On Sun, Oct 27, 2019 at 1:53 PM Toke Høiland-Jørgensen [off-list ref] wrote:
quoted hunk ↗ jump to hunk
From: Toke Høiland-Jørgensen <redacted> This adds a new BPF selftest to exercise the new automatic map pinning code. Signed-off-by: Toke Høiland-Jørgensen <redacted> --- 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.cdiff --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?
quoted hunk ↗ jump to hunk
+ 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";