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-rw-r--r--tools/bpf/bpftool/json_writer.c6
-rw-r--r--tools/bpf/bpftool/json_writer.h3
-rw-r--r--tools/bpf/bpftool/prog.c199
-rw-r--r--tools/include/uapi/linux/bpf.h7
-rw-r--r--tools/lib/bpf/bpf.c16
-rw-r--r--tools/lib/bpf/bpf.h8
-rw-r--r--tools/lib/bpf/libbpf.c69
-rw-r--r--tools/lib/bpf/libbpf.map1
-rw-r--r--tools/testing/selftests/bpf/Makefile3
-rw-r--r--tools/testing/selftests/bpf/prog_tests/metadata.c141
-rw-r--r--tools/testing/selftests/bpf/progs/metadata_unused.c15
-rw-r--r--tools/testing/selftests/bpf/progs/metadata_used.c15
-rwxr-xr-xtools/testing/selftests/bpf/test_bpftool_metadata.sh82
13 files changed, 564 insertions, 1 deletions
diff --git a/tools/bpf/bpftool/json_writer.c b/tools/bpf/bpftool/json_writer.c
index 86501cd3c763..7fea83bedf48 100644
--- a/tools/bpf/bpftool/json_writer.c
+++ b/tools/bpf/bpftool/json_writer.c
@@ -119,6 +119,12 @@ void jsonw_pretty(json_writer_t *self, bool on)
self->pretty = on;
}
+void jsonw_reset(json_writer_t *self)
+{
+ assert(self->depth == 0);
+ self->sep = '\0';
+}
+
/* Basic blocks */
static void jsonw_begin(json_writer_t *self, int c)
{
diff --git a/tools/bpf/bpftool/json_writer.h b/tools/bpf/bpftool/json_writer.h
index 35cf1f00f96c..8ace65cdb92f 100644
--- a/tools/bpf/bpftool/json_writer.h
+++ b/tools/bpf/bpftool/json_writer.h
@@ -27,6 +27,9 @@ void jsonw_destroy(json_writer_t **self_p);
/* Cause output to have pretty whitespace */
void jsonw_pretty(json_writer_t *self, bool on);
+/* Reset separator to create new JSON */
+void jsonw_reset(json_writer_t *self);
+
/* Add property name */
void jsonw_name(json_writer_t *self, const char *name);
diff --git a/tools/bpf/bpftool/prog.c b/tools/bpf/bpftool/prog.c
index f7923414a052..d942c1e3372c 100644
--- a/tools/bpf/bpftool/prog.c
+++ b/tools/bpf/bpftool/prog.c
@@ -29,6 +29,9 @@
#include "main.h"
#include "xlated_dumper.h"
+#define BPF_METADATA_PREFIX "bpf_metadata_"
+#define BPF_METADATA_PREFIX_LEN (sizeof(BPF_METADATA_PREFIX) - 1)
+
const char * const prog_type_name[] = {
[BPF_PROG_TYPE_UNSPEC] = "unspec",
[BPF_PROG_TYPE_SOCKET_FILTER] = "socket_filter",
@@ -151,6 +154,198 @@ static void show_prog_maps(int fd, __u32 num_maps)
}
}
+static void *find_metadata(int prog_fd, struct bpf_map_info *map_info)
+{
+ struct bpf_prog_info prog_info;
+ __u32 prog_info_len;
+ __u32 map_info_len;
+ void *value = NULL;
+ __u32 *map_ids;
+ int nr_maps;
+ int key = 0;
+ int map_fd;
+ int ret;
+ __u32 i;
+
+ memset(&prog_info, 0, sizeof(prog_info));
+ prog_info_len = sizeof(prog_info);
+ ret = bpf_obj_get_info_by_fd(prog_fd, &prog_info, &prog_info_len);
+ if (ret)
+ return NULL;
+
+ if (!prog_info.nr_map_ids)
+ return NULL;
+
+ map_ids = calloc(prog_info.nr_map_ids, sizeof(__u32));
+ if (!map_ids)
+ return NULL;
+
+ 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)
+ goto free_map_ids;
+
+ for (i = 0; i < prog_info.nr_map_ids; i++) {
+ map_fd = bpf_map_get_fd_by_id(map_ids[i]);
+ if (map_fd < 0)
+ goto free_map_ids;
+
+ memset(map_info, 0, sizeof(*map_info));
+ map_info_len = sizeof(*map_info);
+ ret = bpf_obj_get_info_by_fd(map_fd, map_info, &map_info_len);
+ if (ret < 0) {
+ close(map_fd);
+ goto free_map_ids;
+ }
+
+ if (map_info->type != BPF_MAP_TYPE_ARRAY ||
+ map_info->key_size != sizeof(int) ||
+ map_info->max_entries != 1 ||
+ !map_info->btf_value_type_id ||
+ !strstr(map_info->name, ".rodata")) {
+ close(map_fd);
+ continue;
+ }
+
+ value = malloc(map_info->value_size);
+ if (!value) {
+ close(map_fd);
+ goto free_map_ids;
+ }
+
+ if (bpf_map_lookup_elem(map_fd, &key, value)) {
+ close(map_fd);
+ free(value);
+ value = NULL;
+ goto free_map_ids;
+ }
+
+ close(map_fd);
+ break;
+ }
+
+free_map_ids:
+ free(map_ids);
+ return value;
+}
+
+static bool has_metadata_prefix(const char *s)
+{
+ return strncmp(s, BPF_METADATA_PREFIX, BPF_METADATA_PREFIX_LEN) == 0;
+}
+
+static void show_prog_metadata(int fd, __u32 num_maps)
+{
+ const struct btf_type *t_datasec, *t_var;
+ struct bpf_map_info map_info;
+ struct btf_var_secinfo *vsi;
+ bool printed_header = false;
+ struct btf *btf = NULL;
+ unsigned int i, vlen;
+ void *value = NULL;
+ const char *name;
+ int err;
+
+ if (!num_maps)
+ return;
+
+ memset(&map_info, 0, sizeof(map_info));
+ value = find_metadata(fd, &map_info);
+ if (!value)
+ return;
+
+ err = btf__get_from_id(map_info.btf_id, &btf);
+ if (err || !btf)
+ goto out_free;
+
+ t_datasec = btf__type_by_id(btf, map_info.btf_value_type_id);
+ if (!btf_is_datasec(t_datasec))
+ goto out_free;
+
+ vlen = btf_vlen(t_datasec);
+ vsi = btf_var_secinfos(t_datasec);
+
+ /* We don't proceed to check the kinds of the elements of the DATASEC.
+ * The verifier enforces them to be BTF_KIND_VAR.
+ */
+
+ if (json_output) {
+ struct btf_dumper d = {
+ .btf = btf,
+ .jw = json_wtr,
+ .is_plain_text = false,
+ };
+
+ for (i = 0; i < vlen; i++, vsi++) {
+ t_var = btf__type_by_id(btf, vsi->type);
+ name = btf__name_by_offset(btf, t_var->name_off);
+
+ if (!has_metadata_prefix(name))
+ continue;
+
+ if (!printed_header) {
+ jsonw_name(json_wtr, "metadata");
+ jsonw_start_object(json_wtr);
+ printed_header = true;
+ }
+
+ jsonw_name(json_wtr, name + BPF_METADATA_PREFIX_LEN);
+ err = btf_dumper_type(&d, t_var->type, value + vsi->offset);
+ if (err) {
+ p_err("btf dump failed: %d", err);
+ break;
+ }
+ }
+ if (printed_header)
+ jsonw_end_object(json_wtr);
+ } else {
+ json_writer_t *btf_wtr = jsonw_new(stdout);
+ struct btf_dumper d = {
+ .btf = btf,
+ .jw = btf_wtr,
+ .is_plain_text = true,
+ };
+
+ if (!btf_wtr) {
+ p_err("jsonw alloc failed");
+ goto out_free;
+ }
+
+ for (i = 0; i < vlen; i++, vsi++) {
+ t_var = btf__type_by_id(btf, vsi->type);
+ name = btf__name_by_offset(btf, t_var->name_off);
+
+ if (!has_metadata_prefix(name))
+ continue;
+
+ if (!printed_header) {
+ printf("\tmetadata:");
+ printed_header = true;
+ }
+
+ printf("\n\t\t%s = ", name + BPF_METADATA_PREFIX_LEN);
+
+ jsonw_reset(btf_wtr);
+ err = btf_dumper_type(&d, t_var->type, value + vsi->offset);
+ if (err) {
+ p_err("btf dump failed: %d", err);
+ break;
+ }
+ }
+ if (printed_header)
+ jsonw_destroy(&btf_wtr);
+ }
+
+out_free:
+ btf__free(btf);
+ free(value);
+}
+
static void print_prog_header_json(struct bpf_prog_info *info)
{
jsonw_uint_field(json_wtr, "id", info->id);
@@ -228,6 +423,8 @@ static void print_prog_json(struct bpf_prog_info *info, int fd)
emit_obj_refs_json(&refs_table, info->id, json_wtr);
+ show_prog_metadata(fd, info->nr_map_ids);
+
jsonw_end_object(json_wtr);
}
@@ -297,6 +494,8 @@ static void print_prog_plain(struct bpf_prog_info *info, int fd)
emit_obj_refs_plain(&refs_table, info->id, "\n\tpids ");
printf("\n");
+
+ show_prog_metadata(fd, info->nr_map_ids);
}
static int show_prog(int fd)
diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
index 7dd314176df7..a22812561064 100644
--- a/tools/include/uapi/linux/bpf.h
+++ b/tools/include/uapi/linux/bpf.h
@@ -124,6 +124,7 @@ enum bpf_cmd {
BPF_ENABLE_STATS,
BPF_ITER_CREATE,
BPF_LINK_DETACH,
+ BPF_PROG_BIND_MAP,
};
enum bpf_map_type {
@@ -658,6 +659,12 @@ union bpf_attr {
__u32 flags;
} iter_create;
+ struct { /* struct used by BPF_PROG_BIND_MAP command */
+ __u32 prog_fd;
+ __u32 map_fd;
+ __u32 flags; /* extra flags */
+ } prog_bind_map;
+
} __attribute__((aligned(8)));
/* The description below is an attempt at providing documentation to eBPF
diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c
index 82b983ff6569..2baa1308737c 100644
--- a/tools/lib/bpf/bpf.c
+++ b/tools/lib/bpf/bpf.c
@@ -872,3 +872,19 @@ int bpf_enable_stats(enum bpf_stats_type type)
return sys_bpf(BPF_ENABLE_STATS, &attr, sizeof(attr));
}
+
+int bpf_prog_bind_map(int prog_fd, int map_fd,
+ const struct bpf_prog_bind_opts *opts)
+{
+ union bpf_attr attr;
+
+ if (!OPTS_VALID(opts, bpf_prog_bind_opts))
+ return -EINVAL;
+
+ memset(&attr, 0, sizeof(attr));
+ attr.prog_bind_map.prog_fd = prog_fd;
+ attr.prog_bind_map.map_fd = map_fd;
+ attr.prog_bind_map.flags = OPTS_GET(opts, flags, 0);
+
+ return sys_bpf(BPF_PROG_BIND_MAP, &attr, sizeof(attr));
+}
diff --git a/tools/lib/bpf/bpf.h b/tools/lib/bpf/bpf.h
index 015d13f25fcc..8c1ac4b42f90 100644
--- a/tools/lib/bpf/bpf.h
+++ b/tools/lib/bpf/bpf.h
@@ -243,6 +243,14 @@ LIBBPF_API int bpf_task_fd_query(int pid, int fd, __u32 flags, char *buf,
enum bpf_stats_type; /* defined in up-to-date linux/bpf.h */
LIBBPF_API int bpf_enable_stats(enum bpf_stats_type type);
+struct bpf_prog_bind_opts {
+ size_t sz; /* size of this struct for forward/backward compatibility */
+ __u32 flags;
+};
+#define bpf_prog_bind_opts__last_field flags
+
+LIBBPF_API int bpf_prog_bind_map(int prog_fd, int map_fd,
+ const struct bpf_prog_bind_opts *opts);
#ifdef __cplusplus
} /* extern "C" */
#endif
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 550950eb1860..570235dbc922 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -174,6 +174,8 @@ enum kern_feature_id {
FEAT_EXP_ATTACH_TYPE,
/* bpf_probe_read_{kernel,user}[_str] helpers */
FEAT_PROBE_READ_KERN,
+ /* BPF_PROG_BIND_MAP is supported */
+ FEAT_PROG_BIND_MAP,
__FEAT_CNT,
};
@@ -409,6 +411,7 @@ struct bpf_object {
struct extern_desc *externs;
int nr_extern;
int kconfig_map_idx;
+ int rodata_map_idx;
bool loaded;
bool has_subcalls;
@@ -1070,6 +1073,7 @@ static struct bpf_object *bpf_object__new(const char *path,
obj->efile.bss_shndx = -1;
obj->efile.st_ops_shndx = -1;
obj->kconfig_map_idx = -1;
+ obj->rodata_map_idx = -1;
obj->kern_version = get_kernel_version();
obj->loaded = false;
@@ -1428,6 +1432,8 @@ static int bpf_object__init_global_data_maps(struct bpf_object *obj)
obj->efile.rodata->d_size);
if (err)
return err;
+
+ obj->rodata_map_idx = obj->nr_maps - 1;
}
if (obj->efile.bss_shndx >= 0) {
err = bpf_object__init_internal_map(obj, LIBBPF_MAP_BSS,
@@ -3894,6 +3900,52 @@ static int probe_kern_probe_read_kernel(void)
return probe_fd(bpf_load_program_xattr(&attr, NULL, 0));
}
+static int probe_prog_bind_map(void)
+{
+ struct bpf_load_program_attr prg_attr;
+ struct bpf_create_map_attr map_attr;
+ char *cp, errmsg[STRERR_BUFSIZE];
+ struct bpf_insn insns[] = {
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ BPF_EXIT_INSN(),
+ };
+ int ret, map, prog;
+
+ memset(&map_attr, 0, sizeof(map_attr));
+ map_attr.map_type = BPF_MAP_TYPE_ARRAY;
+ map_attr.key_size = sizeof(int);
+ map_attr.value_size = 32;
+ map_attr.max_entries = 1;
+
+ map = bpf_create_map_xattr(&map_attr);
+ if (map < 0) {
+ ret = -errno;
+ cp = libbpf_strerror_r(ret, errmsg, sizeof(errmsg));
+ pr_warn("Error in %s():%s(%d). Couldn't create simple array map.\n",
+ __func__, cp, -ret);
+ return ret;
+ }
+
+ memset(&prg_attr, 0, sizeof(prg_attr));
+ prg_attr.prog_type = BPF_PROG_TYPE_SOCKET_FILTER;
+ prg_attr.insns = insns;
+ prg_attr.insns_cnt = ARRAY_SIZE(insns);
+ prg_attr.license = "GPL";
+
+ prog = bpf_load_program_xattr(&prg_attr, NULL, 0);
+ if (prog < 0) {
+ close(map);
+ return 0;
+ }
+
+ ret = bpf_prog_bind_map(prog, map, NULL);
+
+ close(map);
+ close(prog);
+
+ return ret >= 0;
+}
+
enum kern_feature_result {
FEAT_UNKNOWN = 0,
FEAT_SUPPORTED = 1,
@@ -3934,6 +3986,9 @@ static struct kern_feature_desc {
},
[FEAT_PROBE_READ_KERN] = {
"bpf_probe_read_kernel() helper", probe_kern_probe_read_kernel,
+ },
+ [FEAT_PROG_BIND_MAP] = {
+ "BPF_PROG_BIND_MAP support", probe_prog_bind_map,
}
};
@@ -6468,6 +6523,20 @@ retry_load:
if (ret >= 0) {
if (log_buf && load_attr.log_level)
pr_debug("verifier log:\n%s", log_buf);
+
+ if (prog->obj->rodata_map_idx >= 0 &&
+ kernel_supports(FEAT_PROG_BIND_MAP)) {
+ struct bpf_map *rodata_map =
+ &prog->obj->maps[prog->obj->rodata_map_idx];
+
+ if (bpf_prog_bind_map(ret, bpf_map__fd(rodata_map), NULL)) {
+ cp = libbpf_strerror_r(errno, errmsg, sizeof(errmsg));
+ pr_warn("prog '%s': failed to bind .rodata map: %s\n",
+ prog->name, cp);
+ /* Don't fail hard if can't bind rodata. */
+ }
+ }
+
*pfd = ret;
ret = 0;
goto out;
diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map
index 92ceb48a5ca2..5f054dadf082 100644
--- a/tools/lib/bpf/libbpf.map
+++ b/tools/lib/bpf/libbpf.map
@@ -302,6 +302,7 @@ LIBBPF_0.1.0 {
LIBBPF_0.2.0 {
global:
+ bpf_prog_bind_map;
bpf_program__section_name;
perf_buffer__buffer_cnt;
perf_buffer__buffer_fd;
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 <test_progs.h>
+#include <cgroup_helpers.h>
+#include <network_helpers.h>
+
+#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 <linux/bpf.h>
+#include <bpf/bpf_helpers.h>
+
+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 <linux/bpf.h>
+#include <bpf/bpf_helpers.h>
+
+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
generated by cgit v1.2.3 (git 2.25.1) at 2025-07-02 22:37:56 +0000