Add a selftest to confirm the issue, panic when update attached freplace
prog to PROG_ARRAY map, has been fixed.
cd tools/testing/selftests/bpf; ./test_progs -t tailcall
324/18 tailcalls/tailcall_freplace:OK
324 tailcalls:OK
Summary: 1/18 PASSED, 0 SKIPPED, 0 FAILED
Signed-off-by: Leon Hwang <hffilwlqm@xxxxxxxxx>
---
.../selftests/bpf/prog_tests/tailcalls.c | 82 +++++++++++++++++++
.../selftests/bpf/progs/tailcall_freplace.c | 34 ++++++++
.../testing/selftests/bpf/progs/tc_bpf2bpf.c | 21 +++++
3 files changed, 137 insertions(+)
create mode 100644 tools/testing/selftests/bpf/progs/tailcall_freplace.c
create mode 100644 tools/testing/selftests/bpf/progs/tc_bpf2bpf.c
diff --git a/tools/testing/selftests/bpf/prog_tests/tailcalls.c b/tools/testing/selftests/bpf/prog_tests/tailcalls.c
index 59993fc9c0d7e..d0c6f0d2a4233 100644
--- a/tools/testing/selftests/bpf/prog_tests/tailcalls.c
+++ b/tools/testing/selftests/bpf/prog_tests/tailcalls.c
@@ -3,6 +3,8 @@
#include <test_progs.h>
#include <network_helpers.h>
#include "tailcall_poke.skel.h"
+#include "tailcall_freplace.skel.h"
+#include "tc_bpf2bpf.skel.h"
/* test_tailcall_1 checks basic functionality by patching multiple locations
@@ -1187,6 +1189,84 @@ static void test_tailcall_poke(void)
tailcall_poke__destroy(call);
}
+static void test_tailcall_freplace(void)
+{
+ struct tailcall_freplace *skel = NULL;
+ struct tc_bpf2bpf *tgt_skel = NULL;
+ struct bpf_link *freplace = NULL;
+ struct bpf_map *data_map;
+ int prog_fd, data_fd;
+ char buff[128] = {};
+ __u32 key = 0;
+ int err, val;
+
+ LIBBPF_OPTS(bpf_test_run_opts, topts,
+ .data_in = buff,
+ .data_size_in = sizeof(buff),
+ .repeat = 1,
+ );
+
+ skel = tailcall_freplace__open();
+ if (!ASSERT_OK_PTR(skel, "open skel"))
+ goto out;
+
+ tgt_skel = tc_bpf2bpf__open_and_load();
+ if (!ASSERT_OK_PTR(tgt_skel, "open tgt_skel"))
+ goto out;
+
+ err = bpf_program__set_attach_target(skel->progs.entry,
+ bpf_program__fd(tgt_skel->progs.entry),
+ "subprog");
+ if (!ASSERT_OK(err, "set_attach_target"))
+ goto out;
+
+ err = tailcall_freplace__load(skel);
+ if (!ASSERT_OK(err, "load skel"))
+ goto out;
+
+ freplace = bpf_program__attach_freplace(skel->progs.entry,
+ bpf_program__fd(tgt_skel->progs.entry),
+ "subprog");
+ if (!ASSERT_OK_PTR(freplace, "attatch_freplace"))
+ goto out;
+
+ prog_fd = bpf_program__fd(skel->progs.entry);
+ if (!ASSERT_GE(prog_fd, 0, "prog_fd"))
+ goto out;
+
+ err = bpf_map_update_elem(bpf_map__fd(skel->maps.jmp_table), &key,
+ &prog_fd, BPF_ANY);
+ if (!ASSERT_OK(err, "update jmp_table"))
+ goto out;
+
+ prog_fd = bpf_program__fd(tgt_skel->progs.entry);
+ if (!ASSERT_GE(prog_fd, 0, "prog_fd"))
+ goto out;
+
+ err = bpf_prog_test_run_opts(prog_fd, &topts);
+ ASSERT_OK(err, "test_run");
+ ASSERT_EQ(topts.retval, 1, "test_run retval");
+
+ data_map = bpf_object__find_map_by_name(skel->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, ".bss map_fd"))
+ goto out;
+
+ key = 0;
+ err = bpf_map_lookup_elem(data_fd, &key, &val);
+ ASSERT_OK(err, "tailcall count");
+ ASSERT_EQ(val, 34, "tailcall count");
+
+out:
+ bpf_link__destroy(freplace);
+ tc_bpf2bpf__destroy(tgt_skel);
+ tailcall_freplace__destroy(skel);
+}
+
void test_tailcalls(void)
{
if (test__start_subtest("tailcall_1"))
@@ -1223,4 +1303,6 @@ void test_tailcalls(void)
test_tailcall_bpf2bpf_fentry_entry();
if (test__start_subtest("tailcall_poke"))
test_tailcall_poke();
+ if (test__start_subtest("tailcall_freplace"))
+ test_tailcall_freplace();
}
diff --git a/tools/testing/selftests/bpf/progs/tailcall_freplace.c b/tools/testing/selftests/bpf/progs/tailcall_freplace.c
new file mode 100644
index 0000000000000..fe25343e9d2fa
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/tailcall_freplace.c
@@ -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;
+
+__noinline int
+subprog(struct __sk_buff *skb)
+{
+ volatile int ret = 1;
+
+ count++;
+
+ bpf_tail_call_static(skb, &jmp_table, 0);
+
+ return ret;
+}
+
+SEC("freplace")
+int entry(struct __sk_buff *skb)
+{
+ return subprog(skb);
+}
+
+char __license[] SEC("license") = "GPL";
diff --git a/tools/testing/selftests/bpf/progs/tc_bpf2bpf.c b/tools/testing/selftests/bpf/progs/tc_bpf2bpf.c
new file mode 100644
index 0000000000000..54abda6c3246e
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/tc_bpf2bpf.c
@@ -0,0 +1,21 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/bpf.h>
+#include <bpf/bpf_helpers.h>
+#include "bpf_legacy.h"
+
+__noinline int
+subprog(struct __sk_buff *skb)
+{
+ volatile int ret = 1;
+
+ return ret;
+}
+
+SEC("tc")
+int entry(struct __sk_buff *skb)
+{
+ return subprog(skb);
+}
+
+char __license[] SEC("license") = "GPL";
--
2.44.0
