selftests/bpf: Skip timer cases when bpf_timer is not supported

JIRA: https://issues.redhat.com/browse/RHEL-83826

commit fbdd61c
Author: Leon Hwang <leon.hwang@linux.dev>
Date:   Wed Sep 10 20:57:40 2025 +0800

    selftests/bpf: Skip timer cases when bpf_timer is not supported

    When enable CONFIG_PREEMPT_RT, verifier will reject bpf_timer with
    returning -EOPNOTSUPP.

    Therefore, skip test cases when errno is EOPNOTSUPP.

    cd tools/testing/selftests/bpf
    ./test_progs -t timer
    125     free_timer:SKIP
    456     timer:SKIP
    457/1   timer_crash/array:SKIP
    457/2   timer_crash/hash:SKIP
    457     timer_crash:SKIP
    458     timer_lockup:SKIP
    459     timer_mim:SKIP
    Summary: 5/0 PASSED, 6 SKIPPED, 0 FAILED

    Signed-off-by: Leon Hwang <leon.hwang@linux.dev>
    Link: https://lore.kernel.org/r/20250910125740.52172-3-leon.hwang@linux.dev
    Signed-off-by: Alexei Starovoitov <ast@kernel.org>

Signed-off-by: Gregory Bell <grbell@redhat.com>

Author: Gbell26

tools/testing/selftests/bpf/prog_tests/free_timer.c

@@ -124,6 +124,10 @@ void test_free_timer(void)
 	int err;
 
 	skel = free_timer__open_and_load();
+	if (!skel && errno == EOPNOTSUPP) {
+		test__skip();
+		return;
+	}
 	if (!ASSERT_OK_PTR(skel, "open_load"))
 		return;
 

tools/testing/selftests/bpf/prog_tests/timer.c

@@ -86,6 +86,10 @@ void serial_test_timer(void)
 	int err;
 
 	timer_skel = timer__open_and_load();
+	if (!timer_skel && errno == EOPNOTSUPP) {
+		test__skip();
+		return;
+	}
 	if (!ASSERT_OK_PTR(timer_skel, "timer_skel_load"))
 		return;
 

tools/testing/selftests/bpf/prog_tests/timer_crash.c

@@ -12,6 +12,10 @@ static void test_timer_crash_mode(int mode)
 	struct timer_crash *skel;
 
 	skel = timer_crash__open_and_load();
+	if (!skel && errno == EOPNOTSUPP) {
+		test__skip();
+		return;
+	}
 	if (!ASSERT_OK_PTR(skel, "timer_crash__open_and_load"))
 		return;
 	skel->bss->pid = getpid();

tools/testing/selftests/bpf/prog_tests/timer_lockup.c

@@ -59,6 +59,10 @@ void test_timer_lockup(void)
 	}
 
 	skel = timer_lockup__open_and_load();
+	if (!skel && errno == EOPNOTSUPP) {
+		test__skip();
+		return;
+	}
 	if (!ASSERT_OK_PTR(skel, "timer_lockup__open_and_load"))
 		return;
 

tools/testing/selftests/bpf/prog_tests/timer_mim.c

@@ -65,6 +65,10 @@ void serial_test_timer_mim(void)
 		goto cleanup;
 
 	timer_skel = timer_mim__open_and_load();
+	if (!timer_skel && errno == EOPNOTSUPP) {
+		test__skip();
+		return;
+	}
 	if (!ASSERT_OK_PTR(timer_skel, "timer_skel_load"))
 		goto cleanup;