@@ -1105,6 +1105,412 @@ static void test_tailcall_bpf2bpf_fentry_entry(void)
bpf_object__close(tgt_obj);
}
+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
+ * entry <
+ * subprog --tailcall-> entry
+ */
+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"))
@@ -1139,4 +1545,16 @@ void test_tailcalls(void)
test_tailcall_bpf2bpf_fentry_fexit();
if (test__start_subtest("tailcall_bpf2bpf_fentry_entry"))
test_tailcall_bpf2bpf_fentry_entry();
+ 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();
}
new file mode 100644
@@ -0,0 +1,34 @@
+// 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)
+{
+ volatile int ret = 1;
+
+ count++;
+ subprog_tail(skb);
+ subprog_tail(skb);
+
+ return ret;
+}
+
+char __license[] SEC("license") = "GPL";
new file mode 100644
@@ -0,0 +1,55 @@
+// 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)
+{
+ 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)
+{
+ 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";
new file mode 100644
@@ -0,0 +1,46 @@
+// 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)
+{
+ 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";
Add some test cases to confirm the tailcall hierarchy issue has been fixed. tools/testing/selftests/bpf/test_progs -t tailcalls 235/17 tailcalls/tailcall_bpf2bpf_hierarchy_1:OK 235/18 tailcalls/tailcall_bpf2bpf_hierarchy_fentry:OK 235/19 tailcalls/tailcall_bpf2bpf_hierarchy_fexit:OK 235/20 tailcalls/tailcall_bpf2bpf_hierarchy_fentry_fexit:OK 235/21 tailcalls/tailcall_bpf2bpf_hierarchy_2:OK 235/22 tailcalls/tailcall_bpf2bpf_hierarchy_3:OK 235 tailcalls:OK Summary: 1/22 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 | 34 ++ .../bpf/progs/tailcall_bpf2bpf_hierarchy2.c | 55 +++ .../bpf/progs/tailcall_bpf2bpf_hierarchy3.c | 46 ++ 4 files changed, 553 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