[PATCH v6 3/5] tools: testing: separate out wait_for_pid() into helper header

[Lorenzo Stoakes <lorenzo.stoakes@xxxxxxxxxx>]

It seems tests other than the pidfd tests use the wait_for_pid() function
declared in pidfd.h.

Since we will shortly be modifying pidfd.h in a way that might clash with
other tests, separate this out and update tests accordingly.

Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@xxxxxxxxxx>
---
 tools/testing/selftests/cgroup/test_kill.c    |  2 +-
 .../pid_namespace/regression_enomem.c         |  2 +-
 tools/testing/selftests/pidfd/pidfd.h         | 26 +------------
 tools/testing/selftests/pidfd/pidfd_helpers.h | 39 +++++++++++++++++++
 4 files changed, 42 insertions(+), 27 deletions(-)
 create mode 100644 tools/testing/selftests/pidfd/pidfd_helpers.h

diff --git a/tools/testing/selftests/cgroup/test_kill.c b/tools/testing/selftests/cgroup/test_kill.c
index 0e5bb6c7307a..2367f645fe89 100644
--- a/tools/testing/selftests/cgroup/test_kill.c
+++ b/tools/testing/selftests/cgroup/test_kill.c
@@ -10,7 +10,7 @@
 #include <unistd.h>
 
 #include "../kselftest.h"
-#include "../pidfd/pidfd.h"
+#include "../pidfd/pidfd_helpers.h"
 #include "cgroup_util.h"
 
 /*
diff --git a/tools/testing/selftests/pid_namespace/regression_enomem.c b/tools/testing/selftests/pid_namespace/regression_enomem.c
index 7d84097ad45c..f3e6989c8069 100644
--- a/tools/testing/selftests/pid_namespace/regression_enomem.c
+++ b/tools/testing/selftests/pid_namespace/regression_enomem.c
@@ -12,7 +12,7 @@
 #include <sys/wait.h>
 
 #include "../kselftest_harness.h"
-#include "../pidfd/pidfd.h"
+#include "../pidfd/pidfd_helpers.h"
 
 /*
  * Regression test for:
diff --git a/tools/testing/selftests/pidfd/pidfd.h b/tools/testing/selftests/pidfd/pidfd.h
index 88d6830ee004..0f3fc51cec73 100644
--- a/tools/testing/selftests/pidfd/pidfd.h
+++ b/tools/testing/selftests/pidfd/pidfd.h
@@ -17,6 +17,7 @@
 #include <sys/wait.h>
 
 #include "../kselftest.h"
+#include "pidfd_helpers.h"
 
 #ifndef P_PIDFD
 #define P_PIDFD 3
@@ -68,31 +69,6 @@
 #define PIDFD_SKIP 3
 #define PIDFD_XFAIL 4
 
-static inline int wait_for_pid(pid_t pid)
-{
-	int status, ret;
-
-again:
-	ret = waitpid(pid, &status, 0);
-	if (ret == -1) {
-		if (errno == EINTR)
-			goto again;
-
-		ksft_print_msg("waitpid returned -1, errno=%d\n", errno);
-		return -1;
-	}
-
-	if (!WIFEXITED(status)) {
-		ksft_print_msg(
-		       "waitpid !WIFEXITED, WIFSIGNALED=%d, WTERMSIG=%d\n",
-		       WIFSIGNALED(status), WTERMSIG(status));
-		return -1;
-	}
-
-	ret = WEXITSTATUS(status);
-	return ret;
-}
-
 static inline int sys_pidfd_open(pid_t pid, unsigned int flags)
 {
 	return syscall(__NR_pidfd_open, pid, flags);
diff --git a/tools/testing/selftests/pidfd/pidfd_helpers.h b/tools/testing/selftests/pidfd/pidfd_helpers.h
new file mode 100644
index 000000000000..5637bfe888de
--- /dev/null
+++ b/tools/testing/selftests/pidfd/pidfd_helpers.h
@@ -0,0 +1,39 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef __PIDFD_HELPERS_H
+#define __PIDFD_HELPERS_H
+
+#define _GNU_SOURCE
+#include <errno.h>
+#include <stdlib.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <unistd.h>
+#include "../kselftest.h"
+
+static inline int wait_for_pid(pid_t pid)
+{
+	int status, ret;
+
+again:
+	ret = waitpid(pid, &status, 0);
+	if (ret == -1) {
+		if (errno == EINTR)
+			goto again;
+
+		ksft_print_msg("waitpid returned -1, errno=%d\n", errno);
+		return -1;
+	}
+
+	if (!WIFEXITED(status)) {
+		ksft_print_msg(
+		       "waitpid !WIFEXITED, WIFSIGNALED=%d, WTERMSIG=%d\n",
+		       WIFSIGNALED(status), WTERMSIG(status));
+		return -1;
+	}
+
+	ret = WEXITSTATUS(status);
+	return ret;
+}
+
+#endif /* __PIDFD_HELPERS_H */
-- 
2.47.0