selftests/bpf: Move sys_pidfd_open() into task_local_storage_helpers.h

sys_pidfd_open() is defined twice in both test_bprm_opts.c and
test_local_storage.c, so move it to a common header file. And it will be
used in map_tests as well.
Signed-off-by: Hou Tao <houtao1@huawei.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/r/20220901061938.3789460-4-houtao@huaweicloud.comSigned-off-by: Martin KaFai Lau <martin.lau@kernel.org>

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

@@ -9,18 +9,10 @@
 
 #include "bprm_opts.skel.h"
 #include "network_helpers.h"
-
-#ifndef __NR_pidfd_open
-#define __NR_pidfd_open 434
-#endif
+#include "task_local_storage_helpers.h"
 
 static const char * const bash_envp[] = { "TMPDIR=shouldnotbeset", NULL };
 
-static inline int sys_pidfd_open(pid_t pid, unsigned int flags)
-{
-	return syscall(__NR_pidfd_open, pid, flags);
-}
-
 static int update_storage(int map_fd, int secureexec)
 {
 	int task_fd, ret = 0;

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

@@ -11,15 +11,7 @@
 
 #include "local_storage.skel.h"
 #include "network_helpers.h"
-
-#ifndef __NR_pidfd_open
-#define __NR_pidfd_open 434
-#endif
-
-static inline int sys_pidfd_open(pid_t pid, unsigned int flags)
-{
-	return syscall(__NR_pidfd_open, pid, flags);
-}
+#include "task_local_storage_helpers.h"
 
 static unsigned int duration;
 

tools/testing/selftests/bpf/task_local_storage_helpers.h

+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __TASK_LOCAL_STORAGE_HELPER_H
+#define __TASK_LOCAL_STORAGE_HELPER_H
+
+#include <unistd.h>
+#include <sys/syscall.h>
+#include <sys/types.h>
+
+#ifndef __NR_pidfd_open
+#define __NR_pidfd_open 434
+#endif
+
+static inline int sys_pidfd_open(pid_t pid, unsigned int flags)
+{
+	return syscall(__NR_pidfd_open, pid, flags);
+}
+
+#endif