1 files changed, 139 insertions, 0 deletions
diff --git a/tools/testing/selftests/powerpc/ptrace/child.h b/tools/testing/selftests/powerpc/ptrace/child.h
new file mode 100644
index 000000000000..d7275b7b33dc
--- /dev/null
+++ b/tools/testing/selftests/powerpc/ptrace/child.h
@@ -0,0 +1,139 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Helper functions to sync execution between parent and child processes.
+ *
+ * Copyright 2018, Thiago Jung Bauermann, IBM Corporation.
+ */
+#include <stdio.h>
+#include <stdbool.h>
+#include <semaphore.h>
+
+/*
+ * Information in a shared memory location for synchronization between child and
+ * parent.
+ */
+struct child_sync {
+	/* The parent waits on this semaphore. */
+	sem_t sem_parent;
+
+	/* If true, the child should give up as well. */
+	bool parent_gave_up;
+
+	/* The child waits on this semaphore. */
+	sem_t sem_child;
+
+	/* If true, the parent should give up as well. */
+	bool child_gave_up;
+};
+
+#define CHILD_FAIL_IF(x, sync)						\
+	do {								\
+		if (x) {						\
+			fprintf(stderr,					\
+				"[FAIL] Test FAILED on line %d\n", __LINE__); \
+			(sync)->child_gave_up = true;			\
+			prod_parent(sync);				\
+			return 1;					\
+		}							\
+	} while (0)
+
+#define PARENT_FAIL_IF(x, sync)						\
+	do {								\
+		if (x) {						\
+			fprintf(stderr,					\
+				"[FAIL] Test FAILED on line %d\n", __LINE__); \
+			(sync)->parent_gave_up = true;			\
+			prod_child(sync);				\
+			return 1;					\
+		}							\
+	} while (0)
+
+#define PARENT_SKIP_IF_UNSUPPORTED(x, sync)				\
+	do {								\
+		if ((x) == -1 && (errno == ENODEV || errno == EINVAL)) { \
+			(sync)->parent_gave_up = true;			\
+			prod_child(sync);				\
+			SKIP_IF(1);					\
+		}							\
+	} while (0)
+
+int init_child_sync(struct child_sync *sync)
+{
+	int ret;
+
+	ret = sem_init(&sync->sem_parent, 1, 0);
+	if (ret) {
+		perror("Semaphore initialization failed");
+		return 1;
+	}
+
+	ret = sem_init(&sync->sem_child, 1, 0);
+	if (ret) {
+		perror("Semaphore initialization failed");
+		return 1;
+	}
+
+	return 0;
+}
+
+void destroy_child_sync(struct child_sync *sync)
+{
+	sem_destroy(&sync->sem_parent);
+	sem_destroy(&sync->sem_child);
+}
+
+int wait_child(struct child_sync *sync)
+{
+	int ret;
+
+	/* Wait until the child prods us. */
+	ret = sem_wait(&sync->sem_parent);
+	if (ret) {
+		perror("Error waiting for child");
+		return 1;
+	}
+
+	return sync->child_gave_up;
+}
+
+int prod_child(struct child_sync *sync)
+{
+	int ret;
+
+	/* Unblock the child now. */
+	ret = sem_post(&sync->sem_child);
+	if (ret) {
+		perror("Error prodding child");
+		return 1;
+	}
+
+	return 0;
+}
+
+int wait_parent(struct child_sync *sync)
+{
+	int ret;
+
+	/* Wait until the parent prods us. */
+	ret = sem_wait(&sync->sem_child);
+	if (ret) {
+		perror("Error waiting for parent");
+		return 1;
+	}
+
+	return sync->parent_gave_up;
+}
+
+int prod_parent(struct child_sync *sync)
+{
+	int ret;
+
+	/* Unblock the parent now. */
+	ret = sem_post(&sync->sem_parent);
+	if (ret) {
+		perror("Error prodding parent");
+		return 1;
+	}
+
+	return 0;
+}