selftests: Add tests for automatic map pinning

This adds a new BPF selftest to exercise the new automatic map pinning
code.

Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/157269298209.394725.15420085139296213182.stgit@toke.dk

diff --git a/tools/testing/selftests/bpf/prog_tests/pinning.c b/tools/testing/selftests/bpf/prog_tests/pinning.c
new file mode 100644 (file)
index 0000000..5253889
--- /dev/null
+++ b/tools/testing/selftests/bpf/prog_tests/pinning.c
@@ -0,0 +1,210 @@
+// 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)
+{
+       struct bpf_map_info map_info = {};
+       __u32 map_info_len, duration = 0;
+       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"))
+               return 0;
+
+       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;
+}
+
+void test_pinning(void)
+{
+       const char *file_invalid = "./test_pinning_invalid.o";
+       const char *custpinpath = "/sys/fs/bpf/custom/pinmap";
+       const char *nopinpath = "/sys/fs/bpf/nopinmap";
+       const char *nopinpath2 = "/sys/fs/bpf/nopinmap2";
+       const char *custpath = "/sys/fs/bpf/custom";
+       const char *pinpath = "/sys/fs/bpf/pinmap";
+       const char *file = "./test_pinning.o";
+       __u32 map_id, map_id2, duration = 0;
+       struct stat statbuf = {};
+       struct bpf_object *obj;
+       struct bpf_map *map;
+       int err;
+       DECLARE_LIBBPF_OPTS(bpf_object_open_opts, opts,
+               .pin_root_path = custpath,
+       );
+
+       /* check that opening fails with invalid pinning value in map def */
+       obj = bpf_object__open_file(file_invalid, NULL);
+       err = libbpf_get_error(obj);
+       if (CHECK(err != -EINVAL, "invalid open", "err %d errno %d\n", err, errno)) {
+               obj = NULL;
+               goto out;
+       }
+
+       /* open the valid object file  */
+       obj = bpf_object__open_file(file, NULL);
+       err = libbpf_get_error(obj);
+       if (CHECK(err, "default open", "err %d errno %d\n", err, errno)) {
+               obj = NULL;
+               goto out;
+       }
+
+       err = bpf_object__load(obj);
+       if (CHECK(err, "default load", "err %d errno %d\n", err, errno))
+               goto out;
+
+       /* check that pinmap was pinned */
+       err = stat(pinpath, &statbuf);
+       if (CHECK(err, "stat pinpath", "err %d errno %d\n", err, errno))
+               goto out;
+
+       /* check that nopinmap was *not* pinned */
+       err = stat(nopinpath, &statbuf);
+       if (CHECK(!err || errno != ENOENT, "stat nopinpath",
+                 "err %d errno %d\n", err, errno))
+               goto out;
+
+       /* check that nopinmap2 was *not* pinned */
+       err = stat(nopinpath2, &statbuf);
+       if (CHECK(!err || errno != ENOENT, "stat nopinpath2",
+                 "err %d errno %d\n", err, errno))
+               goto out;
+
+       map_id = get_map_id(obj, "pinmap");
+       if (!map_id)
+               goto out;
+
+       bpf_object__close(obj);
+
+       obj = bpf_object__open_file(file, NULL);
+       if (CHECK_FAIL(libbpf_get_error(obj))) {
+               obj = NULL;
+               goto out;
+       }
+
+       err = bpf_object__load(obj);
+       if (CHECK(err, "default load", "err %d errno %d\n", err, errno))
+               goto out;
+
+       /* check that same map ID was reused for second load */
+       map_id2 = get_map_id(obj, "pinmap");
+       if (CHECK(map_id != map_id2, "check reuse",
+                 "err %d errno %d id %d id2 %d\n", err, errno, map_id, map_id2))
+               goto out;
+
+       /* should be no-op to re-pin same map */
+       map = bpf_object__find_map_by_name(obj, "pinmap");
+       if (CHECK(!map, "find map", "NULL map"))
+               goto out;
+
+       err = bpf_map__pin(map, NULL);
+       if (CHECK(err, "re-pin map", "err %d errno %d\n", err, errno))
+               goto out;
+
+       /* but error to pin at different location */
+       err = bpf_map__pin(map, "/sys/fs/bpf/other");
+       if (CHECK(!err, "pin map different", "err %d errno %d\n", err, errno))
+               goto out;
+
+       /* unpin maps with a pin_path set */
+       err = bpf_object__unpin_maps(obj, NULL);
+       if (CHECK(err, "unpin maps", "err %d errno %d\n", err, errno))
+               goto out;
+
+       /* and re-pin them... */
+       err = bpf_object__pin_maps(obj, NULL);
+       if (CHECK(err, "pin maps", "err %d errno %d\n", err, errno))
+               goto out;
+
+       /* set pinning path of other map and re-pin all */
+       map = bpf_object__find_map_by_name(obj, "nopinmap");
+       if (CHECK(!map, "find map", "NULL map"))
+               goto out;
+
+       err = bpf_map__set_pin_path(map, custpinpath);
+       if (CHECK(err, "set pin path", "err %d errno %d\n", err, errno))
+               goto out;
+
+       /* should only pin the one unpinned map */
+       err = bpf_object__pin_maps(obj, NULL);
+       if (CHECK(err, "pin maps", "err %d errno %d\n", err, errno))
+               goto out;
+
+       /* check that nopinmap was pinned at the custom path */
+       err = stat(custpinpath, &statbuf);
+       if (CHECK(err, "stat custpinpath", "err %d errno %d\n", err, errno))
+               goto out;
+
+       /* remove the custom pin path to re-test it with auto-pinning below */
+       err = unlink(custpinpath);
+       if (CHECK(err, "unlink custpinpath", "err %d errno %d\n", err, errno))
+               goto out;
+
+       err = rmdir(custpath);
+       if (CHECK(err, "rmdir custpindir", "err %d errno %d\n", err, errno))
+               goto out;
+
+       bpf_object__close(obj);
+
+       /* open the valid object file again */
+       obj = bpf_object__open_file(file, NULL);
+       err = libbpf_get_error(obj);
+       if (CHECK(err, "default open", "err %d errno %d\n", err, errno)) {
+               obj = NULL;
+               goto out;
+       }
+
+       /* swap pin paths of the two maps */
+       bpf_object__for_each_map(map, obj) {
+               if (!strcmp(bpf_map__name(map), "nopinmap"))
+                       err = bpf_map__set_pin_path(map, pinpath);
+               else if (!strcmp(bpf_map__name(map), "pinmap"))
+                       err = bpf_map__set_pin_path(map, NULL);
+               else
+                       continue;
+
+               if (CHECK(err, "set pin path", "err %d errno %d\n", err, errno))
+                       goto out;
+       }
+
+       /* should fail because of map parameter mismatch */
+       err = bpf_object__load(obj);
+       if (CHECK(err != -EINVAL, "param mismatch load", "err %d errno %d\n", err, errno))
+               goto out;
+
+       bpf_object__close(obj);
+
+       /* test auto-pinning at custom path with open opt */
+       obj = bpf_object__open_file(file, &opts);
+       if (CHECK_FAIL(libbpf_get_error(obj))) {
+               obj = NULL;
+               goto out;
+       }
+
+       err = bpf_object__load(obj);
+       if (CHECK(err, "custom load", "err %d errno %d\n", err, errno))
+               goto out;
+
+       /* check that pinmap was pinned at the custom path */
+       err = stat(custpinpath, &statbuf);
+       if (CHECK(err, "stat custpinpath", "err %d errno %d\n", err, errno))
+               goto out;
+
+out:
+       unlink(pinpath);
+       unlink(nopinpath);
+       unlink(nopinpath2);
+       unlink(custpinpath);
+       rmdir(custpath);
+       if (obj)
+               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 (file)
index 0000000..f69a4a5
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/test_pinning.c
@@ -0,0 +1,31 @@
+// 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_HASH);
+       __uint(max_entries, 1);
+       __type(key, __u32);
+       __type(value, __u64);
+} nopinmap SEC(".maps");
+
+struct {
+       __uint(type, BPF_MAP_TYPE_ARRAY);
+       __uint(max_entries, 1);
+       __type(key, __u32);
+       __type(value, __u64);
+       __uint(pinning, LIBBPF_PIN_NONE);
+} nopinmap2 SEC(".maps");
+
+char _license[] SEC("license") = "GPL";

diff --git a/tools/testing/selftests/bpf/progs/test_pinning_invalid.c b/tools/testing/selftests/bpf/progs/test_pinning_invalid.c
new file mode 100644 (file)
index 0000000..51b38ab
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/test_pinning_invalid.c
@@ -0,0 +1,16 @@
+// 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, 2); /* invalid */
+} nopinmap3 SEC(".maps");
+
+char _license[] SEC("license") = "GPL";