@@ -218,12 +218,14 @@ static void test_tailcall_2(void)
bpf_object__close(obj);
}
-static void test_tailcall_count(const char *which)
+static void test_tailcall_count(const char *which, bool test_fentry,
+ bool test_fexit)
{
+ struct bpf_object *obj = NULL, *fentry_obj = NULL, *fexit_obj = NULL;
+ struct bpf_link *fentry_link = NULL, *fexit_link = NULL;
int err, map_fd, prog_fd, main_fd, data_fd, i, val;
struct bpf_map *prog_array, *data_map;
struct bpf_program *prog;
- struct bpf_object *obj;
char buff[128] = {};
LIBBPF_OPTS(bpf_test_run_opts, topts,
.data_in = buff,
@@ -265,6 +267,54 @@ static void test_tailcall_count(const char *which)
if (CHECK_FAIL(err))
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(main_fd, &topts);
ASSERT_OK(err, "tailcall");
ASSERT_EQ(topts.retval, 1, "tailcall retval");
@@ -282,6 +332,40 @@ static void test_tailcall_count(const char *which)
ASSERT_OK(err, "tailcall count");
ASSERT_EQ(val, 33, "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;
+
+ data_fd = bpf_map__fd(data_map);
+ if (!ASSERT_FALSE(data_fd < 0,
+ "find tailcall_bpf2bpf_fentry.bss map fd"))
+ goto out;
+
+ i = 0;
+ err = bpf_map_lookup_elem(data_fd, &i, &val);
+ ASSERT_OK(err, "fentry count");
+ ASSERT_EQ(val, 33, "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;
+
+ data_fd = bpf_map__fd(data_map);
+ if (!ASSERT_FALSE(data_fd < 0,
+ "find tailcall_bpf2bpf_fexit.bss map fd"))
+ goto out;
+
+ i = 0;
+ err = bpf_map_lookup_elem(data_fd, &i, &val);
+ ASSERT_OK(err, "fexit count");
+ ASSERT_EQ(val, 33, "fexit count");
+ }
+
i = 0;
err = bpf_map_delete_elem(map_fd, &i);
if (CHECK_FAIL(err))
@@ -291,6 +375,10 @@ static void test_tailcall_count(const char *which)
ASSERT_OK(err, "tailcall");
ASSERT_OK(topts.retval, "tailcall retval");
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);
}
@@ -299,7 +387,7 @@ static void test_tailcall_count(const char *which)
*/
static void test_tailcall_3(void)
{
- test_tailcall_count("tailcall3.bpf.o");
+ test_tailcall_count("tailcall3.bpf.o", false, false);
}
/* test_tailcall_6 checks that the count value of the tail call limit
@@ -307,7 +395,7 @@ static void test_tailcall_3(void)
*/
static void test_tailcall_6(void)
{
- test_tailcall_count("tailcall6.bpf.o");
+ test_tailcall_count("tailcall6.bpf.o", false, false);
}
/* test_tailcall_4 checks that the kernel properly selects indirect jump
@@ -884,6 +972,139 @@ static void test_tailcall_bpf2bpf_6(void)
tailcall_bpf2bpf6__destroy(obj);
}
+/* test_tailcall_bpf2bpf_fentry checks that the count value of the tail call
+ * limit enforcement matches with expectations when tailcall is preceded with
+ * bpf2bpf call, and the bpf2bpf call is traced by fentry.
+ */
+static void test_tailcall_bpf2bpf_fentry(void)
+{
+ test_tailcall_count("tailcall_bpf2bpf2.bpf.o", true, false);
+}
+
+/* test_tailcall_bpf2bpf_fexit checks that the count value of the tail call
+ * limit enforcement matches with expectations when tailcall is preceded with
+ * bpf2bpf call, and the bpf2bpf call is traced by fexit.
+ */
+static void test_tailcall_bpf2bpf_fexit(void)
+{
+ test_tailcall_count("tailcall_bpf2bpf2.bpf.o", false, true);
+}
+
+/* test_tailcall_bpf2bpf_fentry_fexit checks that the count value of the tail
+ * call limit enforcement matches with expectations when tailcall is preceded
+ * with bpf2bpf call, and the bpf2bpf call is traced by both fentry and fexit.
+ */
+static void test_tailcall_bpf2bpf_fentry_fexit(void)
+{
+ test_tailcall_count("tailcall_bpf2bpf2.bpf.o", true, true);
+}
+
+/* test_tailcall_bpf2bpf_fentry_entry checks that the count value of the tail
+ * call limit enforcement matches with expectations when tailcall is preceded
+ * with bpf2bpf call, and the bpf2bpf caller is traced by fentry.
+ */
+static void test_tailcall_bpf2bpf_fentry_entry(void)
+{
+ struct bpf_object *tgt_obj = NULL, *fentry_obj = NULL;
+ int err, map_fd, prog_fd, data_fd, i, val;
+ struct bpf_map *prog_array, *data_map;
+ struct bpf_link *fentry_link = 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_bpf2bpf2.bpf.o",
+ BPF_PROG_TYPE_SCHED_CLS,
+ &tgt_obj, &prog_fd);
+ if (!ASSERT_OK(err, "load tgt_obj"))
+ return;
+
+ prog_array = bpf_object__find_map_by_name(tgt_obj, "jmp_table");
+ if (!ASSERT_OK_PTR(prog_array, "find jmp_table map"))
+ goto out;
+
+ map_fd = bpf_map__fd(prog_array);
+ if (!ASSERT_FALSE(map_fd < 0, "find jmp_table map fd"))
+ goto out;
+
+ prog = bpf_object__find_program_by_name(tgt_obj, "classifier_0");
+ if (!ASSERT_OK_PTR(prog, "find classifier_0 prog"))
+ goto out;
+
+ prog_fd = bpf_program__fd(prog);
+ if (!ASSERT_FALSE(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;
+
+ 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, "classifier_0");
+ if (!ASSERT_OK(err, "set_attach_target classifier_0"))
+ 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;
+
+ 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(tgt_obj, "tailcall.bss");
+ if (!ASSERT_FALSE(!data_map || !bpf_map__is_internal(data_map),
+ "find tailcall.bss map"))
+ goto out;
+
+ data_fd = bpf_map__fd(data_map);
+ if (!ASSERT_FALSE(data_fd < 0, "find tailcall.bss map fd"))
+ goto out;
+
+ i = 0;
+ err = bpf_map_lookup_elem(data_fd, &i, &val);
+ ASSERT_OK(err, "tailcall count");
+ ASSERT_EQ(val, 34, "tailcall count");
+
+ 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;
+
+ data_fd = bpf_map__fd(data_map);
+ if (!ASSERT_FALSE(data_fd < 0,
+ "find tailcall_bpf2bpf_fentry.bss map fd"))
+ goto out;
+
+ i = 0;
+ err = bpf_map_lookup_elem(data_fd, &i, &val);
+ ASSERT_OK(err, "fentry count");
+ ASSERT_EQ(val, 1, "fentry count");
+
+out:
+ bpf_link__destroy(fentry_link);
+ bpf_object__close(fentry_obj);
+ bpf_object__close(tgt_obj);
+}
+
void test_tailcalls(void)
{
if (test__start_subtest("tailcall_1"))
@@ -910,4 +1131,12 @@ void test_tailcalls(void)
test_tailcall_bpf2bpf_4(true);
if (test__start_subtest("tailcall_bpf2bpf_6"))
test_tailcall_bpf2bpf_6();
+ if (test__start_subtest("tailcall_bpf2bpf_fentry"))
+ test_tailcall_bpf2bpf_fentry();
+ if (test__start_subtest("tailcall_bpf2bpf_fexit"))
+ test_tailcall_bpf2bpf_fexit();
+ if (test__start_subtest("tailcall_bpf2bpf_fentry_fexit"))
+ test_tailcall_bpf2bpf_fentry_fexit();
+ if (test__start_subtest("tailcall_bpf2bpf_fentry_entry"))
+ test_tailcall_bpf2bpf_fentry_entry();
}
new file mode 100644
@@ -0,0 +1,18 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright Leon Hwang */
+
+#include "vmlinux.h"
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+
+int count = 0;
+
+SEC("fentry/subprog_tail")
+int BPF_PROG(fentry, struct sk_buff *skb)
+{
+ count++;
+
+ return 0;
+}
+
+char _license[] SEC("license") = "GPL";
new file mode 100644
@@ -0,0 +1,18 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright Leon Hwang */
+
+#include "vmlinux.h"
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+
+int count = 0;
+
+SEC("fexit/subprog_tail")
+int BPF_PROG(fexit, struct sk_buff *skb)
+{
+ count++;
+
+ return 0;
+}
+
+char _license[] SEC("license") = "GPL";
Add 4 test cases to confirm the tailcall infinite loop bug has been fixed. Like tailcall_bpf2bpf cases, do fentry/fexit on the bpf2bpf, and then check the final count result. tools/testing/selftests/bpf/test_progs -t tailcalls 226/13 tailcalls/tailcall_bpf2bpf_fentry:OK 226/14 tailcalls/tailcall_bpf2bpf_fexit:OK 226/15 tailcalls/tailcall_bpf2bpf_fentry_fexit:OK 226/16 tailcalls/tailcall_bpf2bpf_fentry_entry:OK 226 tailcalls:OK Summary: 1/16 PASSED, 0 SKIPPED, 0 FAILED Signed-off-by: Leon Hwang <hffilwlqm@gmail.com> --- .../selftests/bpf/prog_tests/tailcalls.c | 237 +++++++++++++++++- .../bpf/progs/tailcall_bpf2bpf_fentry.c | 18 ++ .../bpf/progs/tailcall_bpf2bpf_fexit.c | 18 ++ 3 files changed, 269 insertions(+), 4 deletions(-) create mode 100644 tools/testing/selftests/bpf/progs/tailcall_bpf2bpf_fentry.c create mode 100644 tools/testing/selftests/bpf/progs/tailcall_bpf2bpf_fexit.c