On 7/24/24 5:32 PM, Leon Hwang wrote:
Add a selftest to confirm the issue, which gets -EINVAL when update
attached freplace prog to PROG_ARRAY map, has been fixed.
cd tools/testing/selftests/bpf; ./test_progs -t tailcalls
327/25 tailcalls/tailcall_freplace:OK
327 tailcalls:OK
Summary: 1/25 PASSED, 0 SKIPPED, 0 FAILED
Signed-off-by: Leon Hwang <leon.hwang@xxxxxxxxx>
---
.../selftests/bpf/prog_tests/tailcalls.c | 76 ++++++++++++++++++-
.../selftests/bpf/progs/tailcall_freplace.c | 33 ++++++++
.../testing/selftests/bpf/progs/tc_bpf2bpf.c | 23 ++++++
3 files changed, 131 insertions(+), 1 deletion(-)
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/progs/tailcall_freplace.c b/tools/testing/selftests/bpf/progs/tailcall_freplace.c
new file mode 100644
index 0000000000000..80b5fa386ed9c
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/tailcall_freplace.c
@@ -0,0 +1,33 @@
+// 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)
+{
+ count++;
+
+ bpf_tail_call_static(skb, &jmp_table, 0);
+
+ return count;
+}
+
+SEC("freplace")
+int entry(struct __sk_buff *skb)
+{
+ return subprog(skb);
+}
+
+char __license[] SEC("license") = "GPL";
+
extra line in the above.
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..4810961554585
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/tc_bpf2bpf.c
@@ -0,0 +1,23 @@
+// 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;
+
+ asm volatile (""::"r+"(ret));
+ return ret;
+}
+
+SEC("tc")
+int entry(struct __sk_buff *skb)
+{
+ return subprog(skb);
+}
+
+char __license[] SEC("license") = "GPL";
+
extra line in the above.
