From: Leon Hwang <hffilwlqm@gmail.com>
To: bpf@vger.kernel.org
Cc: ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org,
maciej.fijalkowski@intel.com, jakub@cloudflare.com,
pulehui@huawei.com, hengqi.chen@gmail.com, hffilwlqm@gmail.com,
kernel-patches-bot@fb.com
Subject: [PATCH bpf-next v3 3/3] selftests/bpf: Add testcases for tailcall hierarchy fixing
Date: Tue, 2 Apr 2024 23:26:38 +0800 [thread overview]
Message-ID: <20240402152638.31377-4-hffilwlqm@gmail.com> (raw)
In-Reply-To: <20240402152638.31377-1-hffilwlqm@gmail.com>
Add some test cases to confirm the tailcall hierarchy issue has been fixed.
tools/testing/selftests/bpf/test_progs -t tailcalls
311/18 tailcalls/tailcall_bpf2bpf_hierarchy_1:OK
311/19 tailcalls/tailcall_bpf2bpf_hierarchy_fentry:OK
311/20 tailcalls/tailcall_bpf2bpf_hierarchy_fexit:OK
311/21 tailcalls/tailcall_bpf2bpf_hierarchy_fentry_fexit:OK
311/22 tailcalls/tailcall_bpf2bpf_hierarchy_2:OK
311/23 tailcalls/tailcall_bpf2bpf_hierarchy_3:OK
311 tailcalls:OK
Summary: 1/23 PASSED, 0 SKIPPED, 0 FAILED
Signed-off-by: Leon Hwang <hffilwlqm@gmail.com>
---
.../selftests/bpf/prog_tests/tailcalls.c | 418 ++++++++++++++++++
.../bpf/progs/tailcall_bpf2bpf_hierarchy1.c | 38 ++
.../bpf/progs/tailcall_bpf2bpf_hierarchy2.c | 63 +++
.../bpf/progs/tailcall_bpf2bpf_hierarchy3.c | 50 +++
4 files changed, 569 insertions(+)
create mode 100644 tools/testing/selftests/bpf/progs/tailcall_bpf2bpf_hierarchy1.c
create mode 100644 tools/testing/selftests/bpf/progs/tailcall_bpf2bpf_hierarchy2.c
create mode 100644 tools/testing/selftests/bpf/progs/tailcall_bpf2bpf_hierarchy3.c
diff --git a/tools/testing/selftests/bpf/prog_tests/tailcalls.c b/tools/testing/selftests/bpf/prog_tests/tailcalls.c
index 59993fc9c0d7e..6b7baafb855af 100644
--- a/tools/testing/selftests/bpf/prog_tests/tailcalls.c
+++ b/tools/testing/selftests/bpf/prog_tests/tailcalls.c
@@ -1187,6 +1187,412 @@ static void test_tailcall_poke(void)
tailcall_poke__destroy(call);
}
+static void test_tailcall_hierarchy_count(const char *which, bool test_fentry,
+ bool test_fexit)
+{
+ int err, map_fd, prog_fd, main_data_fd, fentry_data_fd, fexit_data_fd, i, val;
+ struct bpf_object *obj = NULL, *fentry_obj = NULL, *fexit_obj = NULL;
+ struct bpf_link *fentry_link = NULL, *fexit_link = NULL;
+ struct bpf_map *prog_array, *data_map;
+ struct bpf_program *prog;
+ char buff[128] = {};
+
+ LIBBPF_OPTS(bpf_test_run_opts, topts,
+ .data_in = buff,
+ .data_size_in = sizeof(buff),
+ .repeat = 1,
+ );
+
+ err = bpf_prog_test_load(which, BPF_PROG_TYPE_SCHED_CLS, &obj,
+ &prog_fd);
+ if (!ASSERT_OK(err, "load obj"))
+ return;
+
+ prog = bpf_object__find_program_by_name(obj, "entry");
+ if (!ASSERT_OK_PTR(prog, "find entry prog"))
+ goto out;
+
+ prog_fd = bpf_program__fd(prog);
+ if (!ASSERT_GE(prog_fd, 0, "prog_fd"))
+ goto out;
+
+ prog_array = bpf_object__find_map_by_name(obj, "jmp_table");
+ if (!ASSERT_OK_PTR(prog_array, "find jmp_table"))
+ goto out;
+
+ map_fd = bpf_map__fd(prog_array);
+ if (!ASSERT_GE(map_fd, 0, "map_fd"))
+ goto out;
+
+ i = 0;
+ err = bpf_map_update_elem(map_fd, &i, &prog_fd, BPF_ANY);
+ if (!ASSERT_OK(err, "update jmp_table"))
+ goto out;
+
+ if (test_fentry) {
+ fentry_obj = bpf_object__open_file("tailcall_bpf2bpf_fentry.bpf.o",
+ NULL);
+ if (!ASSERT_OK_PTR(fentry_obj, "open fentry_obj file"))
+ goto out;
+
+ prog = bpf_object__find_program_by_name(fentry_obj, "fentry");
+ if (!ASSERT_OK_PTR(prog, "find fentry prog"))
+ goto out;
+
+ err = bpf_program__set_attach_target(prog, prog_fd,
+ "subprog_tail");
+ if (!ASSERT_OK(err, "set_attach_target subprog_tail"))
+ goto out;
+
+ err = bpf_object__load(fentry_obj);
+ if (!ASSERT_OK(err, "load fentry_obj"))
+ goto out;
+
+ fentry_link = bpf_program__attach_trace(prog);
+ if (!ASSERT_OK_PTR(fentry_link, "attach_trace"))
+ goto out;
+ }
+
+ if (test_fexit) {
+ fexit_obj = bpf_object__open_file("tailcall_bpf2bpf_fexit.bpf.o",
+ NULL);
+ if (!ASSERT_OK_PTR(fexit_obj, "open fexit_obj file"))
+ goto out;
+
+ prog = bpf_object__find_program_by_name(fexit_obj, "fexit");
+ if (!ASSERT_OK_PTR(prog, "find fexit prog"))
+ goto out;
+
+ err = bpf_program__set_attach_target(prog, prog_fd,
+ "subprog_tail");
+ if (!ASSERT_OK(err, "set_attach_target subprog_tail"))
+ goto out;
+
+ err = bpf_object__load(fexit_obj);
+ if (!ASSERT_OK(err, "load fexit_obj"))
+ goto out;
+
+ fexit_link = bpf_program__attach_trace(prog);
+ if (!ASSERT_OK_PTR(fexit_link, "attach_trace"))
+ goto out;
+ }
+
+ err = bpf_prog_test_run_opts(prog_fd, &topts);
+ ASSERT_OK(err, "tailcall");
+ ASSERT_EQ(topts.retval, 1, "tailcall retval");
+
+ data_map = bpf_object__find_map_by_name(obj, ".bss");
+ if (!ASSERT_FALSE(!data_map || !bpf_map__is_internal(data_map),
+ "find data_map"))
+ goto out;
+
+ main_data_fd = bpf_map__fd(data_map);
+ if (!ASSERT_GE(main_data_fd, 0, "main_data_fd"))
+ goto out;
+
+ i = 0;
+ err = bpf_map_lookup_elem(main_data_fd, &i, &val);
+ ASSERT_OK(err, "tailcall count");
+ ASSERT_EQ(val, 34, "tailcall count");
+
+ if (test_fentry) {
+ data_map = bpf_object__find_map_by_name(fentry_obj, ".bss");
+ if (!ASSERT_FALSE(!data_map || !bpf_map__is_internal(data_map),
+ "find tailcall_bpf2bpf_fentry.bss map"))
+ goto out;
+
+ fentry_data_fd = bpf_map__fd(data_map);
+ if (!ASSERT_GE(fentry_data_fd, 0,
+ "find tailcall_bpf2bpf_fentry.bss map fd"))
+ goto out;
+
+ i = 0;
+ err = bpf_map_lookup_elem(fentry_data_fd, &i, &val);
+ ASSERT_OK(err, "fentry count");
+ ASSERT_EQ(val, 68, "fentry count");
+ }
+
+ if (test_fexit) {
+ data_map = bpf_object__find_map_by_name(fexit_obj, ".bss");
+ if (!ASSERT_FALSE(!data_map || !bpf_map__is_internal(data_map),
+ "find tailcall_bpf2bpf_fexit.bss map"))
+ goto out;
+
+ fexit_data_fd = bpf_map__fd(data_map);
+ if (!ASSERT_GE(fexit_data_fd, 0,
+ "find tailcall_bpf2bpf_fexit.bss map fd"))
+ goto out;
+
+ i = 0;
+ err = bpf_map_lookup_elem(fexit_data_fd, &i, &val);
+ ASSERT_OK(err, "fexit count");
+ ASSERT_EQ(val, 68, "fexit count");
+ }
+
+ i = 0;
+ err = bpf_map_delete_elem(map_fd, &i);
+ if (!ASSERT_OK(err, "delete_elem from jmp_table"))
+ goto out;
+
+ err = bpf_prog_test_run_opts(prog_fd, &topts);
+ ASSERT_OK(err, "tailcall");
+ ASSERT_EQ(topts.retval, 1, "tailcall retval");
+
+ i = 0;
+ err = bpf_map_lookup_elem(main_data_fd, &i, &val);
+ ASSERT_OK(err, "tailcall count");
+ ASSERT_EQ(val, 35, "tailcall count");
+
+ if (test_fentry) {
+ i = 0;
+ err = bpf_map_lookup_elem(fentry_data_fd, &i, &val);
+ ASSERT_OK(err, "fentry count");
+ ASSERT_EQ(val, 70, "fentry count");
+ }
+
+ if (test_fexit) {
+ i = 0;
+ err = bpf_map_lookup_elem(fexit_data_fd, &i, &val);
+ ASSERT_OK(err, "fexit count");
+ ASSERT_EQ(val, 70, "fexit count");
+ }
+
+out:
+ bpf_link__destroy(fentry_link);
+ bpf_link__destroy(fexit_link);
+ bpf_object__close(fentry_obj);
+ bpf_object__close(fexit_obj);
+ bpf_object__close(obj);
+}
+
+/* test_tailcall_bpf2bpf_hierarchy_1 checks that the count value of the tail
+ * call limit enforcement matches with expectations when tailcalls are preceded
+ * with two bpf2bpf calls.
+ *
+ * subprog --tailcall-> entry prog
+ * entry prog <
+ * subprog --tailcall-> entry prog
+ */
+static void test_tailcall_bpf2bpf_hierarchy_1(void)
+{
+ test_tailcall_hierarchy_count("tailcall_bpf2bpf_hierarchy1.bpf.o",
+ false, false);
+}
+
+/* test_tailcall_bpf2bpf_hierarchy_fentry checks that the count value of the
+ * tail call limit enforcement matches with expectations when tailcalls are
+ * preceded with two bpf2bpf calls, and the two subprogs are traced by fentry.
+ */
+static void test_tailcall_bpf2bpf_hierarchy_fentry(void)
+{
+ test_tailcall_hierarchy_count("tailcall_bpf2bpf_hierarchy1.bpf.o",
+ true, false);
+}
+
+/* test_tailcall_bpf2bpf_hierarchy_fexit checks that the count value of the tail
+ * call limit enforcement matches with expectations when tailcalls are preceded
+ * with two bpf2bpf calls, and the two subprogs are traced by fexit.
+ */
+static void test_tailcall_bpf2bpf_hierarchy_fexit(void)
+{
+ test_tailcall_hierarchy_count("tailcall_bpf2bpf_hierarchy1.bpf.o",
+ false, true);
+}
+
+/* test_tailcall_bpf2bpf_hierarchy_fentry_fexit checks that the count value of
+ * the tail call limit enforcement matches with expectations when tailcalls are
+ * preceded with two bpf2bpf calls, and the two subprogs are traced by both
+ * fentry and fexit.
+ */
+static void test_tailcall_bpf2bpf_hierarchy_fentry_fexit(void)
+{
+ test_tailcall_hierarchy_count("tailcall_bpf2bpf_hierarchy1.bpf.o",
+ true, true);
+}
+
+/* test_tailcall_bpf2bpf_hierarchy_2 checks that the count value of the tail
+ * call limit enforcement matches with expectations:
+ *
+ * subprog_tail0 --tailcall-> classifier_0 -> subprog_tail0
+ * entry <
+ * subprog_tail1 --tailcall-> classifier_1 -> subprog_tail1
+ */
+static void test_tailcall_bpf2bpf_hierarchy_2(void)
+{
+ int err, map_fd, prog_fd, data_fd, main_fd, i, val[2];
+ struct bpf_map *prog_array, *data_map;
+ struct bpf_object *obj = NULL;
+ struct bpf_program *prog;
+ char buff[128] = {};
+
+ LIBBPF_OPTS(bpf_test_run_opts, topts,
+ .data_in = buff,
+ .data_size_in = sizeof(buff),
+ .repeat = 1,
+ );
+
+ err = bpf_prog_test_load("tailcall_bpf2bpf_hierarchy2.bpf.o",
+ BPF_PROG_TYPE_SCHED_CLS,
+ &obj, &prog_fd);
+ if (!ASSERT_OK(err, "load obj"))
+ return;
+
+ prog = bpf_object__find_program_by_name(obj, "entry");
+ if (!ASSERT_OK_PTR(prog, "find entry prog"))
+ goto out;
+
+ main_fd = bpf_program__fd(prog);
+ if (!ASSERT_GE(main_fd, 0, "main_fd"))
+ goto out;
+
+ prog_array = bpf_object__find_map_by_name(obj, "jmp_table");
+ if (!ASSERT_OK_PTR(prog_array, "find jmp_table map"))
+ goto out;
+
+ map_fd = bpf_map__fd(prog_array);
+ if (!ASSERT_GE(map_fd, 0, "find jmp_table map fd"))
+ goto out;
+
+ prog = bpf_object__find_program_by_name(obj, "classifier_0");
+ if (!ASSERT_OK_PTR(prog, "find classifier_0 prog"))
+ goto out;
+
+ prog_fd = bpf_program__fd(prog);
+ if (!ASSERT_GE(prog_fd, 0, "find classifier_0 prog fd"))
+ goto out;
+
+ i = 0;
+ err = bpf_map_update_elem(map_fd, &i, &prog_fd, BPF_ANY);
+ if (!ASSERT_OK(err, "update jmp_table"))
+ goto out;
+
+ prog = bpf_object__find_program_by_name(obj, "classifier_1");
+ if (!ASSERT_OK_PTR(prog, "find classifier_1 prog"))
+ goto out;
+
+ prog_fd = bpf_program__fd(prog);
+ if (!ASSERT_GE(prog_fd, 0, "find classifier_1 prog fd"))
+ goto out;
+
+ i = 1;
+ err = bpf_map_update_elem(map_fd, &i, &prog_fd, BPF_ANY);
+ if (!ASSERT_OK(err, "update jmp_table"))
+ goto out;
+
+ err = bpf_prog_test_run_opts(main_fd, &topts);
+ ASSERT_OK(err, "tailcall");
+ ASSERT_EQ(topts.retval, 1, "tailcall retval");
+
+ data_map = bpf_object__find_map_by_name(obj, ".bss");
+ if (!ASSERT_FALSE(!data_map || !bpf_map__is_internal(data_map),
+ "find .bss map"))
+ goto out;
+
+ data_fd = bpf_map__fd(data_map);
+ if (!ASSERT_GE(data_fd, 0, "find .bss map fd"))
+ goto out;
+
+ i = 0;
+ err = bpf_map_lookup_elem(data_fd, &i, &val);
+ ASSERT_OK(err, "tailcall counts");
+ ASSERT_EQ(val[0], 33, "tailcall count0");
+ ASSERT_EQ(val[1], 0, "tailcall count1");
+
+out:
+ bpf_object__close(obj);
+}
+
+/* test_tailcall_bpf2bpf_hierarchy_3 checks that the count value of the tail
+ * call limit enforcement matches with expectations:
+ *
+ * subprog with jmp_table0 to classifier_0
+ * entry --tailcall-> classifier_0 <
+ * subprog with jmp_table1 to classifier_0
+ */
+static void test_tailcall_bpf2bpf_hierarchy_3(void)
+{
+ int err, map_fd, prog_fd, data_fd, main_fd, i, val;
+ struct bpf_map *prog_array, *data_map;
+ struct bpf_object *obj = NULL;
+ struct bpf_program *prog;
+ char buff[128] = {};
+
+ LIBBPF_OPTS(bpf_test_run_opts, topts,
+ .data_in = buff,
+ .data_size_in = sizeof(buff),
+ .repeat = 1,
+ );
+
+ err = bpf_prog_test_load("tailcall_bpf2bpf_hierarchy3.bpf.o",
+ BPF_PROG_TYPE_SCHED_CLS,
+ &obj, &prog_fd);
+ if (!ASSERT_OK(err, "load obj"))
+ return;
+
+ prog = bpf_object__find_program_by_name(obj, "entry");
+ if (!ASSERT_OK_PTR(prog, "find entry prog"))
+ goto out;
+
+ main_fd = bpf_program__fd(prog);
+ if (!ASSERT_GE(main_fd, 0, "main_fd"))
+ goto out;
+
+ prog_array = bpf_object__find_map_by_name(obj, "jmp_table0");
+ if (!ASSERT_OK_PTR(prog_array, "find jmp_table0 map"))
+ goto out;
+
+ map_fd = bpf_map__fd(prog_array);
+ if (!ASSERT_GE(map_fd, 0, "find jmp_table0 map fd"))
+ goto out;
+
+ prog = bpf_object__find_program_by_name(obj, "classifier_0");
+ if (!ASSERT_OK_PTR(prog, "find classifier_0 prog"))
+ goto out;
+
+ prog_fd = bpf_program__fd(prog);
+ if (!ASSERT_GE(prog_fd, 0, "find classifier_0 prog fd"))
+ goto out;
+
+ i = 0;
+ err = bpf_map_update_elem(map_fd, &i, &prog_fd, BPF_ANY);
+ if (!ASSERT_OK(err, "update jmp_table0"))
+ goto out;
+
+ prog_array = bpf_object__find_map_by_name(obj, "jmp_table1");
+ if (!ASSERT_OK_PTR(prog_array, "find jmp_table1 map"))
+ goto out;
+
+ map_fd = bpf_map__fd(prog_array);
+ if (!ASSERT_GE(map_fd, 0, "find jmp_table1 map fd"))
+ goto out;
+
+ i = 0;
+ err = bpf_map_update_elem(map_fd, &i, &prog_fd, BPF_ANY);
+ if (!ASSERT_OK(err, "update jmp_table1"))
+ goto out;
+
+ err = bpf_prog_test_run_opts(main_fd, &topts);
+ ASSERT_OK(err, "tailcall");
+ ASSERT_EQ(topts.retval, 1, "tailcall retval");
+
+ data_map = bpf_object__find_map_by_name(obj, ".bss");
+ if (!ASSERT_FALSE(!data_map || !bpf_map__is_internal(data_map),
+ "find .bss map"))
+ goto out;
+
+ data_fd = bpf_map__fd(data_map);
+ if (!ASSERT_GE(data_fd, 0, "find .bss map fd"))
+ goto out;
+
+ i = 0;
+ err = bpf_map_lookup_elem(data_fd, &i, &val);
+ ASSERT_OK(err, "tailcall count");
+ ASSERT_EQ(val, 33, "tailcall count");
+
+out:
+ bpf_object__close(obj);
+}
+
void test_tailcalls(void)
{
if (test__start_subtest("tailcall_1"))
@@ -1223,4 +1629,16 @@ void test_tailcalls(void)
test_tailcall_bpf2bpf_fentry_entry();
if (test__start_subtest("tailcall_poke"))
test_tailcall_poke();
+ if (test__start_subtest("tailcall_bpf2bpf_hierarchy_1"))
+ test_tailcall_bpf2bpf_hierarchy_1();
+ if (test__start_subtest("tailcall_bpf2bpf_hierarchy_fentry"))
+ test_tailcall_bpf2bpf_hierarchy_fentry();
+ if (test__start_subtest("tailcall_bpf2bpf_hierarchy_fexit"))
+ test_tailcall_bpf2bpf_hierarchy_fexit();
+ if (test__start_subtest("tailcall_bpf2bpf_hierarchy_fentry_fexit"))
+ test_tailcall_bpf2bpf_hierarchy_fentry_fexit();
+ if (test__start_subtest("tailcall_bpf2bpf_hierarchy_2"))
+ test_tailcall_bpf2bpf_hierarchy_2();
+ if (test__start_subtest("tailcall_bpf2bpf_hierarchy_3"))
+ test_tailcall_bpf2bpf_hierarchy_3();
}
diff --git a/tools/testing/selftests/bpf/progs/tailcall_bpf2bpf_hierarchy1.c b/tools/testing/selftests/bpf/progs/tailcall_bpf2bpf_hierarchy1.c
new file mode 100644
index 0000000000000..375b486573395
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/tailcall_bpf2bpf_hierarchy1.c
@@ -0,0 +1,38 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/bpf.h>
+#include <bpf/bpf_helpers.h>
+#include "bpf_legacy.h"
+
+struct {
+ __uint(type, BPF_MAP_TYPE_PROG_ARRAY);
+ __uint(max_entries, 1);
+ __uint(key_size, sizeof(__u32));
+ __uint(value_size, sizeof(__u32));
+} jmp_table SEC(".maps");
+
+int count = 0;
+
+static __noinline
+int subprog_tail(struct __sk_buff *skb)
+{
+ bpf_tail_call_static(skb, &jmp_table, 0);
+ return 0;
+}
+
+SEC("tc")
+int entry(struct __sk_buff *skb)
+{
+ int ret = 1;
+
+ if (count >= 100)
+ /* exit for abnormal case */
+ return count;
+
+ count++;
+ subprog_tail(skb);
+ subprog_tail(skb);
+
+ return ret;
+}
+
+char __license[] SEC("license") = "GPL";
diff --git a/tools/testing/selftests/bpf/progs/tailcall_bpf2bpf_hierarchy2.c b/tools/testing/selftests/bpf/progs/tailcall_bpf2bpf_hierarchy2.c
new file mode 100644
index 0000000000000..4bf65d1c73d98
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/tailcall_bpf2bpf_hierarchy2.c
@@ -0,0 +1,63 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/bpf.h>
+#include <bpf/bpf_helpers.h>
+#include "bpf_legacy.h"
+
+struct {
+ __uint(type, BPF_MAP_TYPE_PROG_ARRAY);
+ __uint(max_entries, 2);
+ __uint(key_size, sizeof(__u32));
+ __uint(value_size, sizeof(__u32));
+} jmp_table SEC(".maps");
+
+int count0 = 0;
+int count1 = 0;
+
+static __noinline
+int subprog_tail0(struct __sk_buff *skb)
+{
+ bpf_tail_call_static(skb, &jmp_table, 0);
+ return 0;
+}
+
+SEC("tc")
+int classifier_0(struct __sk_buff *skb)
+{
+ if (count0 >= 100)
+ /* exit for abnormal case */
+ return count0;
+
+ count0++;
+ subprog_tail0(skb);
+ return 0;
+}
+
+static __noinline
+int subprog_tail1(struct __sk_buff *skb)
+{
+ bpf_tail_call_static(skb, &jmp_table, 1);
+ return 0;
+}
+
+SEC("tc")
+int classifier_1(struct __sk_buff *skb)
+{
+ if (count1 >= 100)
+ /* exit for abnormal case */
+ return count1;
+
+ count1++;
+ subprog_tail1(skb);
+ return 0;
+}
+
+SEC("tc")
+int entry(struct __sk_buff *skb)
+{
+ subprog_tail0(skb);
+ subprog_tail1(skb);
+
+ return 1;
+}
+
+char __license[] SEC("license") = "GPL";
diff --git a/tools/testing/selftests/bpf/progs/tailcall_bpf2bpf_hierarchy3.c b/tools/testing/selftests/bpf/progs/tailcall_bpf2bpf_hierarchy3.c
new file mode 100644
index 0000000000000..68c69d4e97fc9
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/tailcall_bpf2bpf_hierarchy3.c
@@ -0,0 +1,50 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/bpf.h>
+#include <bpf/bpf_helpers.h>
+#include "bpf_legacy.h"
+
+struct {
+ __uint(type, BPF_MAP_TYPE_PROG_ARRAY);
+ __uint(max_entries, 1);
+ __uint(key_size, sizeof(__u32));
+ __uint(value_size, sizeof(__u32));
+} jmp_table0 SEC(".maps");
+
+struct {
+ __uint(type, BPF_MAP_TYPE_PROG_ARRAY);
+ __uint(max_entries, 1);
+ __uint(key_size, sizeof(__u32));
+ __uint(value_size, sizeof(__u32));
+} jmp_table1 SEC(".maps");
+
+int count = 0;
+
+static __noinline
+int subprog_tail(struct __sk_buff *skb, void *jmp_table)
+{
+ bpf_tail_call_static(skb, jmp_table, 0);
+ return 0;
+}
+
+SEC("tc")
+int classifier_0(struct __sk_buff *skb)
+{
+ if (count >= 100)
+ /* exit for abnormal case */
+ return count;
+
+ count++;
+ subprog_tail(skb, &jmp_table0);
+ subprog_tail(skb, &jmp_table1);
+ return 1;
+}
+
+SEC("tc")
+int entry(struct __sk_buff *skb)
+{
+ bpf_tail_call_static(skb, &jmp_table0, 0);
+
+ return 0;
+}
+
+char __license[] SEC("license") = "GPL";
--
2.44.0
prev parent reply other threads:[~2024-04-02 15:27 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-02 15:26 [PATCH bpf-next v3 0/3] bpf, x64: Fix tailcall hierarchy Leon Hwang
2024-04-02 15:26 ` [PATCH bpf-next v3 1/3] bpf: Add bpf_tail_call_cnt to task_struct Leon Hwang
2024-04-02 15:26 ` [PATCH bpf-next v3 2/3] bpf, x64: Fix tailcall hierarchy Leon Hwang
2024-04-05 1:03 ` Alexei Starovoitov
2024-04-07 11:34 ` Leon Hwang
2024-04-07 16:30 ` Alexei Starovoitov
2024-04-10 14:09 ` Leon Hwang
2024-04-11 3:42 ` Alexei Starovoitov
2024-04-14 11:47 ` Leon Hwang
2024-04-02 15:26 ` Leon Hwang [this message]
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