selftests/bpf: Check for PREEMPTION instead of PREEMPT

CONFIG_PREEMPT is a preemtion model the so called "Low-Latency Desktop".
A different preemption model is PREEMPT_RT the so called "Real-Time".
Both implement preemption in kernel and set CONFIG_PREEMPTION.
There is also the so called "LAZY PREEMPT" which the "Scheduler
controlled preemption model". Here we have also preemption in the kernel
the rules are slightly different.

Therefore the testsuite should not check for CONFIG_PREEMPT (as one
model) but for CONFIG_PREEMPTION to figure out if preemption in the
kernel is possible.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Link: https://lore.kernel.org/r/20241119161819.qvEcs-n_@linutronix.de
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

tools/testing/selftests/bpf/map_tests/task_storage_map.c

@@ -78,8 +78,8 @@ void test_task_storage_map_stress_lookup(void)
 	CHECK(err, "open_and_load", "error %d\n", err);
 
 	/* Only for a fully preemptible kernel */
-	if (!skel->kconfig->CONFIG_PREEMPT) {
-		printf("%s SKIP (no CONFIG_PREEMPT)\n", __func__);
+	if (!skel->kconfig->CONFIG_PREEMPTION) {
+		printf("%s SKIP (no CONFIG_PREEMPTION)\n", __func__);
 		read_bpf_task_storage_busy__destroy(skel);
 		skips++;
 		return;

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

@@ -197,7 +197,7 @@ static void test_nodeadlock(void)
 	/* Unnecessary recursion and deadlock detection are reproducible
 	 * in the preemptible kernel.
 	 */
-	if (!skel->kconfig->CONFIG_PREEMPT) {
+	if (!skel->kconfig->CONFIG_PREEMPTION) {
 		test__skip();
 		goto done;
 	}

tools/testing/selftests/bpf/progs/read_bpf_task_storage_busy.c

@@ -4,7 +4,7 @@
 #include <bpf/bpf_helpers.h>
 #include <bpf/bpf_tracing.h>
 
-extern bool CONFIG_PREEMPT __kconfig __weak;
+extern bool CONFIG_PREEMPTION __kconfig __weak;
 extern const int bpf_task_storage_busy __ksym;
 
 char _license[] SEC("license") = "GPL";
@@ -24,7 +24,7 @@ int BPF_PROG(read_bpf_task_storage_busy)
 {
 	int *value;
 
-	if (!CONFIG_PREEMPT)
+	if (!CONFIG_PREEMPTION)
 		return 0;
 
 	if (bpf_get_current_pid_tgid() >> 32 != pid)

tools/testing/selftests/bpf/progs/task_storage_nodeadlock.c

@@ -10,7 +10,7 @@ char _license[] SEC("license") = "GPL";
 #define EBUSY 16
 #endif
 
-extern bool CONFIG_PREEMPT __kconfig __weak;
+extern bool CONFIG_PREEMPTION __kconfig __weak;
 int nr_get_errs = 0;
 int nr_del_errs = 0;
 
@@ -29,7 +29,7 @@ int BPF_PROG(socket_post_create, struct socket *sock, int family, int type,
 	int ret, zero = 0;
 	int *value;
 
-	if (!CONFIG_PREEMPT)
+	if (!CONFIG_PREEMPTION)
 		return 0;
 
 	task = bpf_get_current_task_btf();