selftests/bpf: Extract syscall wrapper

Extract the helper to set up SYS_PREFIX for fentry and kprobe selftests
that use __x86_sys_* attach functions.
Suggested-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Kenta Tada <Kenta.Tada@sony.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20220124141622.4378-2-Kenta.Tada@sony.com

tools/testing/selftests/bpf/progs/bpf_misc.h

+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __BPF_MISC_H__
+#define __BPF_MISC_H__
+
+#if defined(__TARGET_ARCH_x86)
+#define SYSCALL_WRAPPER 1
+#define SYS_PREFIX "__x64_"
+#elif defined(__TARGET_ARCH_s390)
+#define SYSCALL_WRAPPER 1
+#define SYS_PREFIX "__s390x_"
+#elif defined(__TARGET_ARCH_arm64)
+#define SYSCALL_WRAPPER 1
+#define SYS_PREFIX "__arm64_"
+#else
+#define SYSCALL_WRAPPER 0
+#define SYS_PREFIX ""
+#endif
+
+#endif

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

@@ -7,20 +7,7 @@
 
 #include <bpf/bpf_helpers.h>
 #include <bpf/bpf_tracing.h>
-
-#if defined(__TARGET_ARCH_x86)
-#define SYSCALL_WRAPPER 1
-#define SYS_PREFIX "__x64_"
-#elif defined(__TARGET_ARCH_s390)
-#define SYSCALL_WRAPPER 1
-#define SYS_PREFIX "__s390x_"
-#elif defined(__TARGET_ARCH_arm64)
-#define SYSCALL_WRAPPER 1
-#define SYS_PREFIX "__arm64_"
-#else
-#define SYSCALL_WRAPPER 0
-#define SYS_PREFIX ""
-#endif
+#include "bpf_misc.h"
 
 static struct sockaddr_in old;