Merge branch 'bpf-arm64-add-fsession-support'

Leon Hwang says:

====================
Similar to commit 98770bd4e6df ("bpf,x86: add fsession support for x86_64"),
add fsession support on arm64.

Patch #1 adds bpf_jit_supports_fsession() to prevent fsession loading
on architectures that do not implement fsession support.

Patch #2 implements fsession support in the arm64 BPF JIT trampoline.

Patch #3 enables the relevant selftests on arm64, including get_func_ip,
and get_func_args.

All enabled tests pass on arm64:

 cd tools/testing/selftests/bpf
 ./test_progs -t fsession
 #136/1   fsession_test/fsession_test:OK
 #136/2   fsession_test/fsession_reattach:OK
 #136/3   fsession_test/fsession_cookie:OK
 #136     fsession_test:OK
 Summary: 1/3 PASSED, 0 SKIPPED, 0 FAILED

 ./test_progs -t get_func
 #138     get_func_args_test:OK
 #139     get_func_ip_test:OK
 Summary: 2/0 PASSED, 0 SKIPPED, 0 FAILED

Changes:
v4 -> v5:
* Address comment from Alexei:
  * Rename helper bpf_link_prog_session_cookie() to
    bpf_prog_calls_session_cookie().
* v4: https://lore.kernel.org/bpf/20260129154953.66915-1-leon.hwang@linux.dev/

v3 -> v4:
* Add a log when !bpf_jit_supports_fsession() in patch #1 (per AI).
* v3: https://lore.kernel.org/bpf/20260129142536.48637-1-leon.hwang@linux.dev/

v2 -> v3:
* Fix typo in subject and patch message of patch #1 (per AI and Chris).
* Collect Acked-by, and Tested-by from Puranjay, thanks.
* v2: https://lore.kernel.org/bpf/20260128150112.8873-1-leon.hwang@linux.dev/

v1 -> v2:
* Add bpf_jit_supports_fsession().
* v1: https://lore.kernel.org/bpf/20260127163344.92819-1-leon.hwang@linux.dev/
====================

Link: https://patch.msgid.link/20260131144950.16294-1-leon.hwang@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

3 files changed, 26 insertions, 10 deletions

diff --git a/tools/testing/selftests/bpf/prog_tests/fsession_test.c b/tools/testing/selftests/bpf/prog_tests/fsession_test.c
index 0c4b428e1cee..a299aeb8cc2e 100644
--- a/tools/testing/selftests/bpf/prog_tests/fsession_test.c
+++ b/tools/testing/selftests/bpf/prog_tests/fsession_test.c
@@ -29,8 +29,16 @@ static void test_fsession_basic(void)
 	struct fsession_test *skel = NULL;
 	int err;
 
-	skel = fsession_test__open_and_load();
-	if (!ASSERT_OK_PTR(skel, "fsession_test__open_and_load"))
+	skel = fsession_test__open();
+	if (!ASSERT_OK_PTR(skel, "fsession_test__open"))
+		return;
+
+	err = fsession_test__load(skel);
+	if (err == -EOPNOTSUPP) {
+		test__skip();
+		goto cleanup;
+	}
+	if (!ASSERT_OK(err, "fsession_test__load"))
 		goto cleanup;
 
 	err = fsession_test__attach(skel);
@@ -47,8 +55,16 @@ static void test_fsession_reattach(void)
 	struct fsession_test *skel = NULL;
 	int err;
 
-	skel = fsession_test__open_and_load();
-	if (!ASSERT_OK_PTR(skel, "fsession_test__open_and_load"))
+	skel = fsession_test__open();
+	if (!ASSERT_OK_PTR(skel, "fsession_test__open"))
+		return;
+
+	err = fsession_test__load(skel);
+	if (err == -EOPNOTSUPP) {
+		test__skip();
+		goto cleanup;
+	}
+	if (!ASSERT_OK(err, "fsession_test__load"))
 		goto cleanup;
 
 	/* first attach */
@@ -94,6 +110,10 @@ static void test_fsession_cookie(void)
 	bpf_program__set_autoload(skel->progs.test6, false);
 
 	err = fsession_test__load(skel);
+	if (err == -EOPNOTSUPP) {
+		test__skip();
+		goto cleanup;
+	}
 	if (!ASSERT_OK(err, "fsession_test__load"))
 		goto cleanup;
 
@@ -111,10 +131,6 @@ cleanup:
 
 void test_fsession_test(void)
 {
-#if !defined(__x86_64__)
-	test__skip();
-	return;
-#endif
 	if (test__start_subtest("fsession_test"))
 		test_fsession_basic();
 	if (test__start_subtest("fsession_reattach"))
diff --git a/tools/testing/selftests/bpf/progs/get_func_args_test.c b/tools/testing/selftests/bpf/progs/get_func_args_test.c
index 0a3236a7a109..180ba5098ca1 100644
--- a/tools/testing/selftests/bpf/progs/get_func_args_test.c
+++ b/tools/testing/selftests/bpf/progs/get_func_args_test.c
@@ -167,7 +167,7 @@ int BPF_PROG(tp_test2)
 }
 
 __u64 test7_result = 0;
-#ifdef __TARGET_ARCH_x86
+#if defined(bpf_target_x86) || defined(bpf_target_arm64)
 SEC("fsession/bpf_fentry_test1")
 int BPF_PROG(test7)
 {
diff --git a/tools/testing/selftests/bpf/progs/get_func_ip_test.c b/tools/testing/selftests/bpf/progs/get_func_ip_test.c
index 65f7e1f182bf..43ff836a8ed8 100644
--- a/tools/testing/selftests/bpf/progs/get_func_ip_test.c
+++ b/tools/testing/selftests/bpf/progs/get_func_ip_test.c
@@ -106,7 +106,7 @@ int BPF_URETPROBE(test8, int ret)
 
 __u64 test9_entry_result = 0;
 __u64 test9_exit_result = 0;
-#ifdef __TARGET_ARCH_x86
+#if defined(bpf_target_x86) || defined(bpf_target_arm64)
 SEC("fsession/bpf_fentry_test1")
 int BPF_PROG(test9, int a)
 {